To see the other types of publications on this topic, follow the link: Valuation of trees and forest land and forest stands.
Journal articles on the topic 'Valuation of trees and forest land and forest stands'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Valuation of trees and forest land and forest stands.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Kovyazin, V. F., K. P. Vinogradov, A. A. Kitcenko, and Е. А. Vasilyeva. "Airborne Laser Scanning for Clarification of the Valuation Indicators of Forest Stands." Lesnoy Zhurnal (Forestry Journal), no. 6 (December 10, 2020): 42–54. http://dx.doi.org/10.37482/0536-1036-2020-6-42-54.
Full textAbstract:
Nowadays the latest non-contact methods and technologies for studying the forest fund are being developed for forest monitoring improvement, forest lands assessment and their cadastral registration. It is the use of airborne laser scanning (ALS) in forest inventory that is designed to solve the challenges forest management facing. Laser scanning is the only method of collecting data on the real surface covered with forest vegetation, which allows to obtain data on the shape, location and reflectivity of the studied forest objects. The result of ALS is a 3D array of laser reflections with a density of up to several dozens of points per 1 m2 and accuracy of determining their coordinates of less than 10 cm in plan and height. Various imported scanning systems are used for surveying. The ALS of the Earth’s vegetation cover is superior to all existing technologies for assessing the quantitative and qualitative parameters of forest stands in a set of characteristics. This method of assessment and inventory of forests has no competitors in the field of monitoring and valuation of forest stands. It also has sufficient accuracy in mapping woody vegetation, up to the tree survey of forested lands. The article proposes a method for determining valuation indicators: species composition, density, stock, height and diameter of forest stands according to the results of ALS in the forest area of the Vsevolozhsk district (Leningrad region). The species composition and density were determined by horizontal projections of tree crowns. The heights of the trees were determined using the Global Mapper software, and their average diameter was found using the diameter and height relationship equations known in forest valuation. The planting stock was calculated using the equations of Dementiev, Dentsin and G. Cuvier. It was found that the results of determining the valuation indicators by means of ALS can be used in forest monitoring along with the data of visual valuation, since the obtained information on the forest stand stays within the limits of permissible errors specified in the forest management instruction.
2
Amidi, Juliette, Jean Mikhael Stephan, and Elias Maatouk. "Reforestation for environmental services as valued by local communities: a case study from Lebanon." Forestry Economics Review 2, no. 1 (April 20, 2020): 97–115. http://dx.doi.org/10.1108/fer-07-2019-0017.
Full textAbstract:
PurposeLebanon has been subject to important reforestation activities which resulted in the establishment of several cedars, pine and other mixed forest stands on communal lands. These stands are not designated for timber production but rather for nonwood forest products (NWFPs), landscape restoration and for environmental services. The study aims at valuating old reforested sites from the perspective of rural communities neighboring those reforested stands.Design/methodology/approachTo assess the non-timber goods and services provided by these forest ecosystems, 13 reforested sites located in different regions in Lebanon were selected. The socioeconomic assessment was done using questionnaires distributed to locals that have close interactions with the neighboring forests; it included, among others, a double-bonded dichotomous contingent valuation (CV) related to their willingness to pay (WTP) for reforestation and forest management activities.FindingsResults of the goods and services assessment revealed that the forests have multifunctional uses with ecotourism as a major activity in all forest types. The CV showed that 75% of respondents did express a WTP. Most of the respondents did so, thus giving a great importance to intrinsic values of the forests. Lower income did not negatively affect the WTP of respondents but rather age and the educational level did. Other factors such as forest type, forest surface and the biodiversity status of the sites did not have an impact on WTP.Practical implicationsThese results are very informative for governmental policies seeking funds to perform reforestation programs for environmental objectives, involving local communities in co-funding these programs would help insure the sustainable conservation of reforestation sites.Social implicationsDespite their relative low income, poor communities are willing to pay to sustain forests and their ecosystem services.Originality/valueIt is the first time that a CV is used for ecosystem services regenerated from 50–60 years old reforested sites in a semiarid region, where trees are not planted for timber production. It is one of the few examples were lower income did not affect the WTP for forests providing environmental services on communal lands.
3
Turusov, Victor, Alexey Chekanyshkin, and Alexandr Lepekhin. "Growth and State of Mixed Stands of Forest Plantations of the Kamennaya Steppe." Lesnoy Zhurnal (Forestry Journal), no. 4 (July 21, 2021): 97–106. http://dx.doi.org/10.37482/0536-1036-2021-4-97-106.
Full textAbstract:
By now, a vast amount of experimental material has been accumulated in the field of protective afforestation of the Central Chernozem Region of Russia, which allows estimating the stability and longevity of various trees and shrubs in different environmental conditions. Good growth and high vitality of woody vegetation largely depend on growing conditions and are determined primarily by the relationship between species (individuals within a species) when they are placed in the forest area and the type of terrain. The researchdifferent combinations in tree and shrub mixing schemes and unequal location by types of terrain. The study was carried out in mature (115–118-year-old) forest strips laid out by the staff of the Kamennaya Steppe experimental forestry G.F. Morozov and N.A. Mikhailov on the territory of the Kamennaya Steppe (Voronezh region, Talovsky district) using archival materials, scientific works of the authors of this article and the employees of the Department of Agroforestry. A comparative analysis of the materials of forest survey work carried out in protective forest plantations created according to the tree-shrub type of mixing on different types of terrain revealed an excess of biometric indicators of tree species growing on the upland type of terrain over those on the slope. It is shown that the initial percentage of participation of English oak is a significant, but not always decisive factor in the creation of oak plantations. They can also be grown with a smaller proportion of this species in the culture, but in this case, timely thinning will be of paramount importance. Over time, there have been significant changes in the composition of plantations, the number of trees and their valuation indicators. There are no viable ash and elm specimens left in the upper tier of the stands. They are severely damaged by stem pests. Certain tree species are damaged by the following pests: common ash by large ash bark beetle (Hylesinus crenatus) and ash bark beetle (Hylesinus fraxini); elm species by cambium-feeding beetles (large elm bark beetle (Scolytus scolytus), European elm bark beetle (Scolytus multistriatus), and pygmy elm bark beetle (Scolytus pygmaeus); English oak by gold pit oak splendour beetle (Chrysobothris affinis), oak borer (Agrilus angustulus), longhorn beetle (Plagionotus detritus), and European oak bark beetle (Scolytus intricatus). The predominant number of trees of all tree species belongs to the categories of limited viable and inviable.
4
Gribacheva, O. V., and A. I. Chernodubov. "Distribution of English Oak (Quercus robur L.) and Norway Maple (Acer platanoides L.) with Height in a Shelterbelt." Lesnoy Zhurnal (Forestry Journal), no. 6 (December 10, 2020): 111–19. http://dx.doi.org/10.37482/0536-1036-2020-6-111-119.
Full textAbstract:
The organizing framework of adaptive landscape agriculture is protective afforestation. The study of the shelterbelt state is necessary for detection of their protective height due to the dramatically changing climatic conditions. The research purpose is to carry out the distribution of trees of English oak (Quercus robur L.) and Norway maple (Acer platanoides L.) with height for the stand structure evaluation, as well as to propose the measures for the condition improvement of English oak. The shelterbelt, the spatial structure of which was studied, is located in the vicinity of the village of Zolotarevka (65 km from the city of Lugansk). Archival data on the creation time and age of the studied forest shelterbelt were not revealed. Shelterbelts in the Lugansk region were created in accordance with the “Great Plan for the Transformation of Nature”, which was designed for 1949–1965. Sampling areas were laid out in accordance with the industrial standard OST 56-69–83. The composition of the shelterbelt, the diameter and average height of the trees were determined based on the results of enumerative valuation. The coefficients of skewness and kurtosis of stands of the studied species were calculated by the standard methods of biometrics. The distribution of Norway maple and English oak trees with height was checked with the normal distribution of trees in the plantation according to the Shapiro-Wilk test. The authors revealed that arithmetic and valuation mean heights of the stands of English oak and Norway maple on two permanent sampling areas differ slightly. It was found that the stand of Norway maple on the first and second sampling areas is characterized by positive right-side symmetry and positive kurtosis. Analyzing the stand condition, it is arguable that the coefficient of skewness of the English Oak stand on both areas is not the same in sign and numerical value: on the first sampling area – leftside negative (As = –2.026) and on the second – right-side positive (As = 0.973). The authors pay particular attention to the fact that the value of the coefficient of kurtosis of the English Oak stands is the highest on the first sampling area – 3.044. On the basis of the Shapiro-Wilk test it is shown that the curve of distribution of the Norway maple stands with height on the first and second sampling areas does not correspond to the normal distribution curve for the plantations. While the curve of distribution of the English Oak stands with height on the second sampling area is close to the indicator of the Shapiro-Wilk test for normal stands and is 0.823 (for p = 0.05, W = 0.842, n = 10).
5
Chang, Sun Joseph. "Forest valuation under the generalized Faustmann formula." Canadian Journal of Forest Research 44, no. 1 (January 2014): 56–63. http://dx.doi.org/10.1139/cjfr-2013-0298.
Full textAbstract:
This paper attempts to address the question of how the value of the forest, the land, and the standing timber should be determined under the generalized Faustmann formula when the beginning and ending value of the land may be different. First, the formulas to determine the value of the forest and the land under such a situation were derived. These formulas were then used to separate the value of the trees from that of the forest. A comparison of the correctly determined valuations of the land against those obtained through a frequently used approximation method showed that at interest rates commonly used, the approximation method overestimates the land value and underestimates the value of the standing timber. Sensitivity analyses showed that higher future land value tends to affect the value of the land less at the beginning of the rotation and more at the end. Its impact on the value of the standing timber may or may not be affected, depending on whether the optimal harvest age is affected or not. Higher final harvest value and higher interest rate affect both the value of the land and the value of the standing timber throughout the entire rotation. Lastly, higher regeneration at the beginning of the rotation simply re-allocates the forest value between that of the land and that of the standing timber, reducing the former while increasing the latter.
6
Michalčík, M. "A contribution to creating groups of trees for forest valuation." Journal of Forest Science 51, No. 4 (January 10, 2012): 177–85. http://dx.doi.org/10.17221/4557-jfs.
Full textAbstract:
During the construction of model logging costs for valuation of forest stands, by accident I found out differences between some species included in the groups of tree species. Differences within the groups of species may cause errors in logging costs of some species, for example with hornbeam, all species of linden, all species of rowans and horse chestnut. With the help of simple calculations it was proved that the differences could be very large, that they were more than forty per cent, it means they were significant. On the basis of my further research it is envisaged to increase the number of groups of trees from 13 to 16. The purpose is to give the most accurate background to make up a model of logging costs. In the second step it is expected that the model can provide the results for more or fewer groups of trees more easily if statistical methods are used. But this problem is not a part of this paper.
7
Czernyszewicz, Eugenia, Małgorzata Szymańska, Beata Żuraw, and Katarzyna Leziak. "The Effect of Location on the Value of Ornamental Trees Using the Example of a Green Space in Lublin." Real Estate Management and Valuation 27, no. 4 (December 1, 2019): 53–61. http://dx.doi.org/10.2478/remav-2019-0035.
Full textAbstract:
Abstract This paper examines and identifies, using a specific example, how the location of trees influences their value. For the valuation of trees outside a forest area, appraisers often employ methods recommended for estimating forest stands, which significantly reduces the value of trees and valued properties. The tree-valuation method developed by SZCZEPANOWSKA et al. (2010) was used in our study. First, we compiled an inventory of trees located on plots intended for expropriation. The study covered all specimens with trunk circumferences of over 25 centimetres, which amounted to a total of 76 trees. We considered the value of the trees in the conditions of the actual location, which means that our calculations included house gardens in the city and the values of the same trees in hypothetical growth conditions: tree stands in rural and urban areas, green spaces in urban and rural areas, housing estates, roads and streets (both urban and rural), and historic areas, health resorts and health-resort protection zones. Our study has shown that the tree valuation method based on differentiating coefficients is a very useful tool for establishing the value of trees in outlying areas.
8
Adamowicz, Krzysztof, Magdalena Gwiazdowicz, and Piotr Szczypa. "Applicability of book value to estimate property of Polish forest management units." Folia Forestalia Polonica 59, no. 3 (September 1, 2017): 231–38. http://dx.doi.org/10.1515/ffp-2017-0024.
Full textAbstract:
AbstractAt present, various solutions are proposed for the appraisal of forest land and stands. Recently an important problem concerning business information is connected with the valuation of assets of individual forest districts. In practice, numerous methods are used to estimate the property of enterprises. However, there are no universal methods to estimate the value of an enterprise. One of these practically applicable methods is the book value method (BVM). In view of the above, it was decided to analyse the applicability of this method to valuate the property of forest districts. Based on the conducted case study and the discussion of results, it was found that the original BV method may not be used to appraise the property of forest districts. The primary justification for rejection of this method in the valuation of forest district property results was from the lack of financial balance information on the value of forest land and stands. As a result, the value of a forest district calculated using the BVM is underestimated. A lesser but significant effect on the estimated value of forest districts is also observed for cash flows related with the Forest Fund. In the case of net contributors, the estimated value of forest districts is overestimated and that of net beneficiaries is underestimated.
9
Susaeta, Andres, and Chris Demers. "The Optimal Forest Management of an Even-Aged Stand: The Biological Rotation versus the Land Expectation Value." EDIS 2019, no. 6 (December 2, 2019): 4. http://dx.doi.org/10.32473/edis-fr424-2019.
Full textAbstract:
This 4-page fact sheet written by Andres Susaeta and Chris Demers and published by the UF/IFAS School of Forest Resources and Conservation provides a guide for forest landowners, managers, and stakeholders in conducting a valuation of timber investments. It reviews and provides examples of two different approaches for determining the optimal rotation age of even-aged forest stands. These methods can help forest landowners and managers in making forestry investment decisions. https://edis.ifas.ufl.edu/fr424
10
Frelich, Lee. "Forest dynamics." F1000Research 5 (February 17, 2016): 183. http://dx.doi.org/10.12688/f1000research.7412.1.
Full textAbstract:
Forest dynamics encompass changes in stand structure, species composition, and species interactions with disturbance and environment over a range of spatial and temporal scales. For convenience, spatial scale is defined as individual tree, neighborhood, stand, and landscape. Whether a given canopy-leveling disturbance will initiate a sequence of development in structure with little change in composition or initiate an episode of succession depends on a match or mismatch, respectively, with traits of the dominant tree species that allow the species to survive disturbance. When these match, certain species-disturbance type combinations lock in a pattern of stand and landscape dynamics that can persist for several generations of trees; thus, dominant tree species regulate, as well as respond to, disturbance. A complex interaction among tree species, neighborhood effects, disturbance type and severity, landform, and soils determines how stands of differing composition form and the mosaic of stands that compose the landscape. Neighborhood effects (e.g., serotinous seed rain, sprouting, shading, leaf-litter chemistry, and leaf-litter physical properties) operate at small spatial extents of the individual tree and its neighbors but play a central role in forest dynamics by contributing to patch formation at stand scales and dynamics of the entire landscape. Dominance by tree species with neutral to negative neighborhood effects leads to unstable landscape dynamics in disturbance-prone regions, wherein most stands are undergoing succession; stability can only occur under very low-severity disturbance regimes. Dominance by species with positive effects leads to stable landscape dynamics wherein only a small proportion of stands undergo succession at any one time. Positive neighborhood effects are common in temperate and boreal zones, whereas negative effects are more common in tropical climates. Landscapes with positive dynamics have alternate categories of dynamics stabilized by high-severity and low-severity disturbance regimes. Contrary to prevailing ecological theory, systems with positive neighborhood effects can have similar levels of compositional stability across tree, stand, and landscape scales. Neighborhood effect theory can help explain responses of landscapes to large-scale land clearing and novel effects brought on by factors such as invasive species and deer overabundance.
11
Ahmed, Junaid, and Sanjay Sharma. "Effect of forest fire on floristic composition, structure, dominance and species richness in subtropical pine forest of Ponda watershed, Rajouri, J&K." Environment Conservation Journal 15, no. 1&2 (June 18, 2014): 61–68. http://dx.doi.org/10.36953/ecj.2014.151208.
Full textAbstract:
Forest fires have profound impacts on physical environment including land cover, land use, forest ecosystem and biodiversity. In the present study the effect of fires on floristic composition, structure, dominance and species richness in subtropical pine forest of Ponda watershed, Rajouri, J&K, lying at an altitude range of 800 m to 1000 m above mean sea level, was assessed. The forests in the study area were divided into two strata i.e., burnt and un-burnt forest. Random sampling was carried out by laying out forty sample plots in all, with twenty sample plots in each strata covering burnt and unburnt forest sites of the study area. The plot dimensions of 20m x 20m were used for studying trees and 5m x 5m for shrubs (laid within the plots for trees). The density, basal area and IVI along with diversity and concentration of dominance of trees and shrubs in both forest sites were studied. Similarity index was also calculated for burnt and unburnt forest of the study area. The results show that the total density and total basal area of trees and shrubs was highest in un-burnt forest sites with density values of 468.75 and 5284 individuals/ha and 85.33 m2/ha and 25.42 m2/ha, respectively. The results on the basis of the comparison of IVI values of all species in both forest stands also reveal that the respective dominant tree and shrub species were Pinus roxburghii and Carissa opaca. The calculated values of Shannon-Wiener, Margalef and Menhinick indices i.e. 1.93, 2.53 and 0.82 for trees and 1.80, 2.08 and 0.44 for shrubs, respectively, reveal that the species richness and diversity was high for unburnt forest stand whereas, Simpson’s index value of tree (0.48) and shrub (0.75) show that an concentration of dominance was highest in burnt forest stands. The calculated value of Sorenson’s and Jaccard’s index of similarity for trees (0.60 and 0.43) was maximum as compare to shrubs (0.47 and 0.31) which shows that forest fire have profound effect on shrub than trees.
12
Byler, James W., Michael A. Marsden, and Susan K. Hagle. "The probability of root disease on the Lolo National Forest, Montana." Canadian Journal of Forest Research 20, no. 7 (July 1, 1990): 987–94. http://dx.doi.org/10.1139/x90-132.
Full textAbstract:
Root disease killed trees in 33% of 579 stands on the Lolo National Forest, Montana. Of all the commercial forest land, 123 255 ha, or 18.8%, was diseased; 1.2% was in nonstocked patches. The statistical method CART (classification and regression trees) was used to construct a decision tree to place stands into one of four classes, based on the probability that the stands contained trees that were killed by root disease. High probabilities of root disease were found for stands in the western hemlock and grand fir habitat type series (0.59) and in other habitat types on moderate slopes with southerly aspects (0.48). Low probabilities of disease were found on non-hemlock and non grand fir types on northerly aspects (0.15) and southerly aspects that were on either flat or very rugged terrain (0.17). Both Phellinusweirii (Murr.) Gilb. and Armillaria sp., probably A. ostoyae (Romagna) Herick, were frequently associated with mortality in hemlock, grand fir, and cedar habitat type series. Only A. ostoyae was common on Douglas-fir and subalpine fir habitat type series, however. Selective harvest and fire control in these two classes may contribute to the extensive root disease mortality found in Lolo National Forest at present.
13
Oliva, Jonàs, Magnus Thor, and Jan Stenlid. "Long-term effects of mechanized stump treatment against Heterobasidion annosum root rot in Picea abies." Canadian Journal of Forest Research 40, no. 6 (June 2010): 1020–33. http://dx.doi.org/10.1139/x10-051.
Full textAbstract:
Airborne Heterobasidion annosum (Fr.) Bref. sensu lato infections can be controlled by winter thinning or by mechanically spreading urea or Phlebiopsis gigantea (Fr.) Jülich spores on stump surfaces during summer thinning operations. The long-term outcomes of these control methods when applied as part of the conventional forest operations are unclear. We studied the rot incidence and population structure of H. annosum in plots of Picea abies (L.) Karst. thinned in winter or thinned in summer with and without treatment of the stumps. Plots were distributed among 11 stands in Sweden representing two different land use histories: forest and agricultural. After 13 years, the effect of stump treatment on rot incidence was only evident in stands on former agricultural land. In stands planted on former forest land with higher levels of preexisting rot than on former agricultural land, the expansion of preexisting genets of H. annosum might have masked the effects of stump protection. In former forest land, unprotected summer plots showed a greater diversity of H. annosum genotypes and a smaller number of trees infected by each genet than in protected plots, suggesting that protection treatments prevented the establishment of new genets, which may result in a reduced rot incidence in the future.
14
Oravec, Milan, and Marián Slamka. "The energy intensity of the production of energy chips from dendromass stands on long-term uncultivated agricultural land." Central European Forestry Journal 64, no. 2 (June 1, 2018): 104–15. http://dx.doi.org/10.1515/forj-2017-0033.
Full textAbstract:
Abstract The aim of this work was to investigate the energy intensity of the fuel wood chips production on unused agricultural land. The unused agricultural land, overgrown with forest trees, also called white areas, is the result of the end of the traditional intensive management of agricultural land by the natural succession of forest stands and pioneers’ wood species on the borders of forest and non-forest land. These stands are advantageously localized due to previous method of the land utilization, accessible and therefore very interesting from the point of view of obtaining fuel dendromass. The logging and subsequent dendromass processing was carried out for the purpose of further land use as pasture land and also for the production of fuel wood chips and their subsequent sale to the end user. With the utilization of technology chain saw-forwarder-chipper, the energy intensity of each operation, expressed in terms of the amount of fuel consumed per unit of produced wood fuel, was determined. The share of energy consumed in the energy value of the harvested tree dendromass in the evaluated sites ranged from 0.43 to 0.62%, approximately 0.64 to 0.88% and the chipping 0.42 to 0.54%. The total amount of energy consumed after calculation the chipper transfers to an average distance of 180 km was within 1.46 to 2.11%. The average weight of the harvested trees caused the biggest impact on the energy intensity of the production process.
15
Dechesne, Clément, Clément Mallet, Arnaud Le Bris, Valérie Gouet, and Alexandre Hervieu. "FOREST STAND SEGMENTATION USING AIRBORNE LIDAR DATA AND VERY HIGH RESOLUTION MULTISPECTRAL IMAGERY." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B3 (June 9, 2016): 207–14. http://dx.doi.org/10.5194/isprsarchives-xli-b3-207-2016.
Full textAbstract:
Forest stands are the basic units for forest inventory and mapping. Stands are large forested areas (e.g., ≥ 2 ha) of homogeneous tree species composition. The accurate delineation of forest stands is usually performed by visual analysis of human operators on very high resolution (VHR) optical images. This work is highly time consuming and should be automated for scalability purposes. In this paper, a method based on the fusion of airborne laser scanning data (or lidar) and very high resolution multispectral imagery for automatic forest stand delineation and forest land-cover database update is proposed. The multispectral images give access to the tree species whereas 3D lidar point clouds provide geometric information on the trees. Therefore, multi-modal features are computed, both at pixel and object levels. The objects are individual trees extracted from lidar data. A supervised classification is performed at the object level on the computed features in order to coarsely discriminate the existing tree species in the area of interest. The analysis at tree level is particularly relevant since it significantly improves the tree species classification. A probability map is generated through the tree species classification and inserted with the pixel-based features map in an energetical framework. The proposed energy is then minimized using a standard graph-cut method (namely QPBO with α-expansion) in order to produce a segmentation map with a controlled level of details. Comparison with an existing forest land cover database shows that our method provides satisfactory results both in terms of stand labelling and delineation (matching ranges between 94% and 99%).
16
Dechesne, Clément, Clément Mallet, Arnaud Le Bris, Valérie Gouet, and Alexandre Hervieu. "FOREST STAND SEGMENTATION USING AIRBORNE LIDAR DATA AND VERY HIGH RESOLUTION MULTISPECTRAL IMAGERY." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B3 (June 9, 2016): 207–14. http://dx.doi.org/10.5194/isprs-archives-xli-b3-207-2016.
Full textAbstract:
Forest stands are the basic units for forest inventory and mapping. Stands are large forested areas (e.g., ≥ 2 ha) of homogeneous tree species composition. The accurate delineation of forest stands is usually performed by visual analysis of human operators on very high resolution (VHR) optical images. This work is highly time consuming and should be automated for scalability purposes. In this paper, a method based on the fusion of airborne laser scanning data (or lidar) and very high resolution multispectral imagery for automatic forest stand delineation and forest land-cover database update is proposed. The multispectral images give access to the tree species whereas 3D lidar point clouds provide geometric information on the trees. Therefore, multi-modal features are computed, both at pixel and object levels. The objects are individual trees extracted from lidar data. A supervised classification is performed at the object level on the computed features in order to coarsely discriminate the existing tree species in the area of interest. The analysis at tree level is particularly relevant since it significantly improves the tree species classification. A probability map is generated through the tree species classification and inserted with the pixel-based features map in an energetical framework. The proposed energy is then minimized using a standard graph-cut method (namely QPBO with α-expansion) in order to produce a segmentation map with a controlled level of details. Comparison with an existing forest land cover database shows that our method provides satisfactory results both in terms of stand labelling and delineation (matching ranges between 94% and 99%).
17
Rédei, Károly, János Gál, Zsolt Keserű, and Borbála Antal. "Above-Ground Biomass of Black Locust (Robinia pseudoacacia L.) Trees and Stands." Acta Silvatica et Lignaria Hungarica 13, no. 2 (December 1, 2017): 113–24. http://dx.doi.org/10.1515/aslh-2017-0008.
Full textAbstract:
Abstract The increasing demand for forest products, diminishing forest land areas, and general concern about the long-term effects of deforestation have increased the need for multipurpose tree species with rapid growth rates. Consequently, information on renewable energy resources is becoming increasingly crucial, and forest biomass determination is becoming a significant part of forestry. Black locust (Robinia pseudoacacia L.) is a fast growing, nitrogen fixing, stress tolerant species with durable and high quality wood that can be used for many purposes including wall panelling; vine props; furniture; pulp and paper; animal feed stock; bee forage; and biomass energy. This article presents the above-ground biomass of black locust, both for individual trees and for stands. Information concerning wet and absolute dry wood for stem, merchantable (d1.3 > 5 cm) and small (d 1.3 < 5 cm) wood, and for other tree parts (foliage, bark) for individual trees and for black locust stands are detailed in dendromass tables by six yield classes.
18
Fraser, Benjamin T., and Russell G. Congalton. "Estimating Primary Forest Attributes and Rare Community Characteristics Using Unmanned Aerial Systems (UAS): An Enrichment of Conventional Forest Inventories." Remote Sensing 13, no. 15 (July 28, 2021): 2971. http://dx.doi.org/10.3390/rs13152971.
Full textAbstract:
The techniques for conducting forest inventories have been established over centuries of land management and conservation. In recent decades, however, compelling new tools and methodologies in remote sensing, computer vision, and data science have offered innovative pathways for enhancing the effectiveness and comprehension of these sampling designs. Now with the aid of Unmanned Aerial Systems (UAS) and advanced image processing techniques, we have never been closer to mapping forests at field-based inventory scales. Our research, conducted in New Hampshire on complex mixed-species forests, used natural color UAS imagery for estimating individual tree diameters (diameter at breast height (dbh)) as well as stand level estimates of Basal Area per Hectare (BA/ha), Quadratic Mean Diameter (QMD), Trees per Hectare (TPH), and a Stand Density Index (SDI) using digital photogrammetry. To strengthen our understanding of these forests, we also assessed the proficiency of the UAS to map the presence of large trees (i.e., >40 cm in diameter). We assessed the proficiency of UAS digital photogrammetry for identifying large trees in two ways: (1) using the UAS estimated dbh and the 40 cm size threshold and (2) using a random forest supervised classification and a combination of spectral, textural, and geometric features. Our UAS-based estimates of tree diameter reported an average error of 19.7% to 33.7%. At the stand level, BA/ha and QMD were overestimated by 42.18% and 62.09%, respectively, while TPH and SDI were underestimated by 45.58% and 3.34%. When considering only stands larger than 9 ha however, the overestimation of BA/ha at the stand level dropped to 14.629%. The overall classification of large trees, using the random forest supervised classification achieved an overall accuracy of 85%. The efficiency and effectiveness of these methods offer local land managers the opportunity to better understand their forested ecosystems. Future research into individual tree crown detection and delineation, especially for co-dominant or suppressed trees, will further support these efforts.
19
Musienko, S., O. Lyalin, L. Tkach, V. Babenko, and M. Sułkowska. "Characteristics and Current Situation of Urban Forests in Kharkiv Region." Folia Forestalia Polonica 60, no. 3 (September 1, 2018): 183–91. http://dx.doi.org/10.2478/ffp-2018-0018.
Full textAbstract:
Abstract The main aim of our study was to examine the current state and to analyse the prospects of the development of urban forests in the city of Kharkiv. Modern methods of assessment and forest resources ranking were used in the evaluation process. The data from the last basic forest inventory and the electronic database of the ‘Ukrderzhlisproekt’ Production Association are used.Conducted investigation enables to assess the state of the urban forests in Kharkiv, to show the division of forest resources by the land category, to list the species composition according to the forests stakeholders as well as to compare the existing and optimal division subject to the age group and to calculate the average forest valuation indicators. Our results indicated that the urban forests have different indicators in the context of permanent users. The existing division of the forest stands by the age group and average forest valuation indicators do not satisfy the optimal ones. Thereby, the vital problem in solving the issue of the conducting forestry in the urban forests transferred to the scientific base for the provision of their optimal growth, development and carrying out of their functions in full exists to date.
20
Šturm, Tomaž, and Tomaž Podobnikar. "A probability model for long-term forest fire occurrence in the Karst forest management area of Slovenia." International Journal of Wildland Fire 26, no. 5 (2017): 399. http://dx.doi.org/10.1071/wf15192.
Full textAbstract:
The aim of this study is to develop a long-term forest fire occurrence probability model in the Karst forest management area of Slovenia. The target area has the greatest forest fire occurrence rates and the largest burned areas in the country. To discover how the forest stand characteristics influence forest fire occurrence, we developed a long-term linear regression model. The geographically weighted regression method was applied to build the model, using forest management plans and land-based datasets as explanatory variables and a past forest fire activity dataset as a predicted variable. The land-based dataset was used to represent human activity as a key component in fire occurrence. Variables representing the natural and the anthropogenic environment used in the model explained 39% of past forest fire occurrences and predicted areas with the highest likelihood of forest fire occurrence. The results show that forest fire occurrence probability in a stand increases with lower wood stock, lower species diversity and lower thickness diversity, and in stands dominated by conifer trees under normal canopy closure. These forests stand characteristics are planned to be used in forest management and silviculture planning to reduce fire damage in Slovenian forests.
21
Steininger, Marc K. "Secondary forest structure and biomass following short and extended land-use in central and southern Amazonia." Journal of Tropical Ecology 16, no. 5 (September 2000): 689–708. http://dx.doi.org/10.1017/s0266467400001656.
Full textAbstract:
A study was conducted on the effect of extended land-use on secondary forest biomass accumulation in the Amazon. Structural measurements were made in a series of secondary forest stands, from 4–30 y old, in Brazil and Bolivia. Half of the stands were forest regrowth following clearance and only 1 y of cultivation; the other half were regrowth following 4 y or more of continuous pasture in Brazil and three or more rotations of medium-fallow agriculture in Bolivia. Above-ground live biomass was estimated using published allometric equations. Total biomass ranged from 17 to 207 Mg ha−1. Biomass of pioneer trees was poorly related to stand age, while that of later-successional trees increased linearly with age. Total biomass accumulation in Bolivia averaged 5.4 Mg ha−1 y−1 over the entire age sequence. Biomass accumulation for regrowth following short-term use was not greater than that for regrowth following medium-fallow agriculture. In Brazil, biomass accumulation averaged 9.1 Mg ha−1 y−1 over the first 12 y of regrowth and 5.9 Mg ha−1 y−1 over the entire age sequence. Biomass accumulation was significantly slower, around 5.0 Mg ha−1 y−1, for regrowth following continuous pasture than for regrowth following 1 y of cultivation.
22
Lucier, Alan A. "Pine Growth-Rate Changes in the Southeast: A Summary of Key Issues for Forest Managers." Southern Journal of Applied Forestry 12, no. 2 (May 1, 1988): 84–89. http://dx.doi.org/10.1093/sjaf/12.2.84.
Full textAbstract:
Abstract Forest inventory data collected by the USDA Forest Service shows that pine forests in the Southeast have changed in many ways since the 1950s. The average age and density of natural stands has increased substantially over the past 30 years, perhaps reflecting the maturation of a large number of stands established between 1945 and 1965. Growth rates of some classes of trees and stands have decreased, but it is not known whether increases in age and density are largely responsible. The existence of growth reductions in natural stands is an expected consequence of the documented changes in stand conditions. The magnitude of the growth reductions, however, cannot be objectively defined as normal or abnormal on the basis of existing data. Researchers are attempting to define the contributions of stand conditions, drought, land-use patterns, atmospheric pollutants, and other factors to observed growth reductions. There is at present no demonstrated link between air pollutants and growth reductions in natural pine stands and no evidence of growth reductions on intensively managed forest industry lands. South. J. Appl. For. 12(2):84-89.
23
Taylor, Anthony R., Donnie A. McPhee, and Judy A. Loo. "Incidence of beech bark disease resistance in the eastern Acadian forest of North America." Forestry Chronicle 89, no. 05 (October 2013): 690–95. http://dx.doi.org/10.5558/tfc2013-122.
Full textAbstract:
Beech bark disease (BBD) is a fatal affliction of American beech (Fagus grandifolia Ehrh.) in North America. Although natural resistance to BBD has been observed, reports vary with respect to incidence of resistance, with 1% being most commonly acknowledged. In this paper, we provide the first formal, empirical estimate of BBD resistance over a wide geographical area where BBD has been prevalent for longest in North America. We conducted our study in the Acadian Forest region of eastern Canada. Thirty-five beech-dominated stands (>5 ha each) were surveyed across the provinces of New Brunswick, Nova Scotia, and Prince Edward Island, spanning a time since infection (TSI) period between 1890 and 1975. Stands were surveyed for incidence of disease-free beech trees, which was used as a proxy for BBD resistance. Across our study area, the average percentage of disease-free trees observed was 3.3%; however, the occurrence of disease-free trees varied significantly geographically, with the oldest, most southerly TSI zone indicating 2.2% and the youngest, most northerly TSI zone showing 5.7%. Although geographic variation of disease-free beech trees may reflect disease exposure time, we speculate that lower minimum winter temperatures, combined with less intensive land-use history are the underlying mechanisms that explain the higher observed percentage of disease-free trees in the most northerly TSI zones.
24
Adermann, Veiko, Allar Padari, Risto Sirgmets, Aija Kosk, and Paavo Kaimre. "Valuation of timber production and carbon sequestration on Järvselja nature protection area." Forestry Studies 63, no. 1 (December 1, 2015): 29–43. http://dx.doi.org/10.1515/fsmu-2015-0007.
Full textAbstract:
Abstract Järvselja nature protection area was established in order to preserve and introduce virgin forests, to protect old natural forests, old deciduous forests and habitats of different species. At the same time the stands of nature protection area provide other benefits having both use and non-use values. The goal of the study is to assess the monetary value of the two components of forest ecosystem: timber production and carbon sequestration. The value of timber expresses to forest owners and policy-makers the opportunity cost of nature protection. The carbon sequestration represents the value of new service, highly appreciated in the context of climate policy. While a market for timber and carbon exists, the market-price method has been used for valuation. The data for calculations was obtained from the materials of forest inventory carried out in 2010 by the Department of Forest Management, Estonian University of Life Sciences. According to the calculations the theoretical long-term average value of timber is 325 euros per hectare. The monetary value of timber production is approximately three times higher compared to average productivity of Estonian private forests. The guidelines of Intergovernmental Panel on Climate Change for the inventories of greenhouse gases were used when transforming the growing stock and dead stem timber into biomass and finally into carbon and carbon dioxide. According to the price 4.62 € per ton of tradeable carbon equivalent in autumn 2013, the value of carbon sequestration on Järvselja nature protection area could be estimated 1473 € per hectare of forest land. Because of the high age of stands on nature protection area, the role of forests as a sequestrator of CO2 is remarkable compared to commercial forests. The accumulation of carbon in old-growth natural forests is close to zero, but they still fulfil the role of being a carbon pool.
25
Taylor, Benton N., Robin L. Chazdon, Benedicte Bachelot, and Duncan N. L. Menge. "Nitrogen-fixing trees inhibit growth of regenerating Costa Rican rainforests." Proceedings of the National Academy of Sciences 114, no. 33 (July 31, 2017): 8817–22. http://dx.doi.org/10.1073/pnas.1707094114.
Full textAbstract:
More than half of the world’s tropical forests are currently recovering from human land use, and this regenerating biomass now represents the largest carbon (C)-capturing potential on Earth. How quickly these forests regenerate is now a central concern for both conservation and global climate-modeling efforts. Symbiotic nitrogen-fixing trees are thought to provide much of the nitrogen (N) required to fuel tropical secondary regrowth and therefore to drive the rate of forest regeneration, yet we have a poor understanding of how these N fixers influence the trees around them. Do they promote forest growth, as expected if the new N they fix facilitates neighboring trees? Or do they suppress growth, as expected if competitive inhibition of their neighbors is strong? Using 17 consecutive years of data from tropical rainforest plots in Costa Rica that range from 10 y since abandonment to old-growth forest, we assessed how N fixers influenced the growth of forest stands and the demographic rates of neighboring trees. Surprisingly, we found no evidence that N fixers facilitate biomass regeneration in these forests. At the hectare scale, plots with more N-fixing trees grew slower. At the individual scale, N fixers inhibited their neighbors even more strongly than did nonfixing trees. These results provide strong evidence that N-fixing trees do not always serve the facilitative role to neighboring trees during tropical forest regeneration that is expected given their N inputs into these systems.
26
Piotti, Andrea, Matteo Garbarino, Camilla Avanzi, Roberta Berretti, Renzo Motta, Paolo Piovani, and Stefano Leonardi. "Influence of Spatiotemporal Dynamics on the Fine-Scale Spatial Genetic Structure of Differently Managed Picea abies Stands." Forests 9, no. 10 (October 10, 2018): 622. http://dx.doi.org/10.3390/f9100622.
Full textAbstract:
The tandem analysis of dendrochronological and genetic data is piquing forest ecologists’ interest and represents a promising approach for studying the temporal development of genetic structure in forest tree populations. Such multidisciplinary approach can help elucidate to what extent different management practices have impacted the fine-scale spatial genetic structure of forest stands through time. In this study, we jointly analysed spatial, age and genetic data from three differently managed Norway spruce permanent plots to assess: (1) possible differences among plots in the spatial distribution of individuals and their genetic structure due to different management practices, and (2) whether modifications in the age structure influenced the fine-scale spatial genetic structure within each permanent plot. With these aims, we genetically characterized at five nuclear microsatellite markers a large subset (328) of all the trees for which spatial and age data were collected (1472). We found that different management practices determined a similar spatial structure in terms of trees’ ages (r < 25 m in all plots) and neutral genetic diversity (Sp ranging from 0.002 to 0.004). Hot spots and cold spots of trees’ age were not statistically different in terms of genetic diversity, and trees’ age was not statistically different among the genetic clusters detected. On the other hand, the spatial distribution of individuals was significantly clustered up to 22 m only in the wooded pasture plot. Our main findings show that forest land use and management can indeed determine markedly different spatial layouts of Norway spruce individuals but do not produce strong distortions in the spatial structure of age and genetic parameters.
27
Plieninger, Tobias, Fernando J. Pulido, and Werner Konold. "Effects of land-use history on size structure of holm oak stands in Spanish dehesas: implications for conservation and restoration." Environmental Conservation 30, no. 1 (March 2003): 61–70. http://dx.doi.org/10.1017/s0376892903000055.
Full textAbstract:
Dehesas, rangelands occupied by scattered oak trees and characterized by silvopastoral uses, cover about 3.1 million ha in south-western Spain. There is considerable debate about the long-term persistence of holm oak (Quercus ilex) populations in dehesas, since most stands are overaged and seedlings and saplings are sparse. The forest cycle has been disrupted in most dehesas. Regeneration has been inhibited since stands were opened for agriculture and grazing. Oak diameters from three land-use groups (young dehesa [YD], middle-aged dehesa [MD], and old dehesa [OD]) in Cáceres Province, Spain, were compared. These groups differed in the age of the land-use system, i.e. time since the original Mediterranean forest was cleared. The dehesa systems were established about 80 (YD), 150 (MD) and 500 (OD) years ago. An analysis of 66 holm oak cross sections revealed a close correlation (r2 = 91.2%) between tree rings and diameters, so that diameter seems to be a reliable indicator of tree age. Nested analysis of variance showed significant variation in diameters between the land-use groups. There is generally a positive relationship between tree age and the age of agrosilvopastoral use of the dehesas. Sparse holm oaks in the dehesas are primarily remnants from the first forest cycle. Local differences in growth conditions (for example soil quality and tree density) contribute further significant diameter variation on a between-plot level. Diameter structure of abandoned dehesas showed two peaks and a high proportion of trees in the smallest size class. This indicates that the forest degradation process is reversible. An effective regeneration policy should promote a rotating 20- to 30-year set-aside of dehesa parcels.
28
Triwiyanto, Chandra Nur, Priyono Suryanto, and Budiadi _. "DRY-FIELD (TEGALAN) AGROFORESTRY SYSTEMS AS MINIATURE NATURE FOREST IN OUTSIDE FOREST AREA ON BULU - GIRIPURWO VILLAGE, GIRIMULYO DISTRICT, KULONPROGO." KnE Life Sciences 2, no. 1 (September 20, 2015): 213. http://dx.doi.org/10.18502/kls.v2i1.145.
Full textAbstract:
<p>A dry-field (tegalan) is one of the subsystems of classical agroforestry, where there is no intensive management of both the spacing and the selection of the type that is considered. Dry-field (tegalan) agroforestry subsystems have a state that resembles natural forest ecosystems. It became an opportunity execution of research related to the stands composition of dry-field (tegalan) and forest nature. The purpose of this study is to determine the pattern of developing agroforestry in Bulu and the relation of the natural forest. This research was conducted in Bulu-Giripurwo Village, Girimulyo District, Kulonprogo. Data was collected at 36 sample plots representing 3 strata. The first stratum had an area of < 1000 m2, the second 1,000 m2–2,000 m2, and the third > 2,000 m2. K-Means Cluster Analysis and exponential equation modeling was used to analyze the dry-field (tegalan). The results of this study indicate that there were three models of management of cultivated land in Bulu; the Mixed Model, Model MPTS dominant plants, and forest trees dominant model. Mixed models had the stand equation Y = 3.39 x 2.7128-0,026X with an R2 of 0.798. The dominant MPTS plan models had the stand equation 3,155 x 2.7128-0,021X with an R2 of 0.770. The dominant of forest trees models has stands equation Y = 3.182 x 2.7128-0,024X with R2 of 0.706. These results demonstrate agroforestry modeling subsystem dry-field (tegalan) has characteristics resembling natural forest indicated from the value of R2 that characterized so close with the equation of uneven-aged forest model.</p><p><br /><strong>Keywords</strong>: Agroforestry, dry-field (tegalan), natural forest</p>
29
MOLDOVAN, Mircea C., Liviu BOCA, Tudor LUNGU, Ioan TĂUT, and Marcel DÎRJA. "Evolution of the Stands Established on Degradated Lands in the Diviciorii Mari Area." Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Horticulture 76, no. 1 (June 12, 2019): 83. http://dx.doi.org/10.15835/buasvmcn-hort:2018.0051.
Full textAbstract:
The introduction of some agricultural land which has partially or totally lost their production capacity is and will be a very important action of Romanian forestry. This extends the forest fund and improves the climatic conditions around the planting areas. The research was carried out in two improvement perimeters near Diviciorii Mari, which assumed measurements of tree diameters, heights and harvesting increment cores. After the analysis of the data and increment cores, the results were associated with climatic data and the stands were found to sufferfrom the effects of prolonged droughts. Also, these trees suffer from drying, windfalls and breaks of crowns due to the combination of droughts with slope and soil. The results obtained from the research were compared with the researches carried out at the Mineci-Ungureni Forest District between 1944 and 1955 and similarities were found regarding the influence of droughts on the radial and, implicitly, forest growths.
30
Applegate, Jason R., and Jim Steinman. "A Comparison of Tree Health Among Forest Types and Conditions at Fort A.P. Hill, Virginia." Southern Journal of Applied Forestry 29, no. 3 (August 1, 2005): 143–47. http://dx.doi.org/10.1093/sjaf/29.3.143.
Full textAbstract:
Abstract Fort A.P. Hill's Range and Training Land Assessments (RTLA) program initiated long-term monitoring of installation forests to assess forest health and ensure optimal sustainability of forest resources for military training activities. A subset of forest health indicators developed by the USDA Forest Service Forest Health Monitoring (FHM) and Forest Inventory and Analysis programs were used to assess forest health on Army training lands at Fort A.P. Hill, Virginia. Indicators of tree crown condition and tree damage condition were taken in forested areas where military training occurs, “tactical concealment areas (TCAs),” and on continuous forest monitoring (CFM) plots established in control stands where military training is absent. A higher percent of trees with high crown dieback, low crown density, and multiple types of stem damage were observed within TCAs than on CFM plots. The results are indicative of possible long-term changes to forest health from military training activities. The FHM forest health indicators proved to be an effective and useful approach to assess tree conditions. South. J. Appl. For. 29(3):143–147.
31
Mushinski, Ryan M., Richard P. Phillips, Zachary C. Payne, Rebecca B. Abney, Insu Jo, Songlin Fei, Sally E. Pusede, Jeffrey R. White, Douglas B. Rusch, and Jonathan D. Raff. "Microbial mechanisms and ecosystem flux estimation for aerobic NOyemissions from deciduous forest soils." Proceedings of the National Academy of Sciences 116, no. 6 (January 18, 2019): 2138–45. http://dx.doi.org/10.1073/pnas.1814632116.
Full textAbstract:
Reactive nitrogen oxides (NOy; NOy= NO + NO2+ HONO) decrease air quality and impact radiative forcing, yet the factors responsible for their emission from nonpoint sources (i.e., soils) remain poorly understood. We investigated the factors that control the production of aerobic NOyin forest soils using molecular techniques, process-based assays, and inhibitor experiments. We subsequently used these data to identify hotspots for gas emissions across forests of the eastern United States. Here, we show that nitrogen oxide soil emissions are mediated by microbial community structure (e.g., ammonium oxidizer abundances), soil chemical characteristics (pH and C:N), and nitrogen (N) transformation rates (net nitrification). We find that, while nitrification rates are controlled primarily by chemoautotrophic ammonia-oxidizing archaea (AOA), the production of NOyis mediated in large part by chemoautotrophic ammonia-oxidizing bacteria (AOB). Variation in nitrification rates and nitrogen oxide emissions tracked variation in forest communities, as stands dominated by arbuscular mycorrhizal (AM) trees had greater N transformation rates and NOyfluxes than stands dominated by ectomycorrhizal (ECM) trees. Given mapped distributions of AM and ECM trees from 78,000 forest inventory plots, we estimate that broadleaf forests of the Midwest and the eastern United States as well as the Mississippi River corridor may be considered hotspots of biogenic NOyemissions. Together, our results greatly improve our understanding of NOyfluxes from forests, which should lead to improved predictions about the atmospheric consequences of tree species shifts owing to land management and climate change.
32
Proutsos, Nikolaos, Alexandra Solomou, George Karetsos, Konstantinia Tsagari, George Mantakas, Konstantinos Kaoukis, Athanassios Bourletsikas, and George Lyrintzis. "The Ecological Status of Juniperus foetidissima Forest Stands in the Mt. Oiti-Natura 2000 Site in Greece." Sustainability 13, no. 6 (March 23, 2021): 3544. http://dx.doi.org/10.3390/su13063544.
Full textAbstract:
Junipers face multiple threats induced both by climate and land use changes, impacting their expansion and reproductive dynamics. The aim of this work is to evaluate the ecological status of Juniperus foetidissima Willd. forest stands in the protected Natura 2000 site of Mt. Oiti in Greece. The study of the ecological status is important for designing and implementing active management and conservation actions for the species’ protection. Tree size characteristics (height, breast height diameter), age, reproductive dynamics, seed production and viability, tree density, sex, and habitat expansion were examined. The data analysis revealed a generally good ecological status of the habitat with high plant diversity. However, at the different juniper stands, subpopulations present high variability and face different problems, such as poor tree density, reduced numbers of juvenile trees or poor seed production, inadequate male:female ratios, a small number of female trees, reduced numbers of seeds with viable embryos, competition with other woody species, grazing, and illegal logging. From the results, the need for site-specific active management and interventions is demonstrated in order to preserve or achieve the good status of the habitat at all stands in the region.
33
Vaughan, Damon, David Auty, Thomas Kolb, Joseph Dahlen, Andrew J. Sánchez Meador, and Kurt H. Mackes. "Wood density variation in naturally regenerated stands of Pinus ponderosa in northern Arizona, USA." Canadian Journal of Forest Research 51, no. 4 (April 2021): 583–94. http://dx.doi.org/10.1139/cjfr-2020-0245.
Full textAbstract:
In the southwestern United States, land managers are implementing large-scale forest restoration projects involving treatments designed to improve forest health, protect ecosystem services, and reduce the risk of catastrophic wildfire in overstocked ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.) forests. A better understanding of wood properties is necessary to improve the currently limited markets for the woody byproducts generated by these treatments. Therefore, our objective was to investigate variations in ponderosa pine wood density across the northern Arizona landscape. We sampled trees from 18 naturally regenerated stands and used X-ray densitometry to quantify the radial and axial variation within and among trees. We modeled within-stem wood density patterns using generalized additive models, and investigated the effects of climatic variation using response function analyses. Additionally, we tested the effects of site-level predictors on whole-tree wood density. We found high variability in radial wood density profiles among trees in our stands compared with that observed in studies of other species grown in plantations — perhaps due to high genetic variation within naturally regenerated stands. Wood density was negatively correlated with precipitation at annual and most quarterly intervals, except for a positive correlation with late-summer monsoon precipitation. The high wood density variation we found among trees highlights the need for further investigation of controls over wood properties in natural nonplantation forests.
34
Imbeau, Louis, Jean-Pierre L. Savard, and Réjean Gagnon. "Comparing bird assemblages in successional black spruce stands originating from fire and logging." Canadian Journal of Zoology 77, no. 12 (December 1, 1999): 1850–60. http://dx.doi.org/10.1139/z99-172.
Full textAbstract:
Comparisons of the effects of logging and fire as disturbance agents on the composition of bird assemblages in boreal ecosystems are still lacking or are limited to the short-term impacts of clear-cutting. In Quebec, where the boreal forest is largely dominated by black spruce (Picea mariana (Mill.) B.S.P.) stands, we surveyed 140 point-count stations in 3 postlogging and 4 postfire development stages determined according to the height of the regenerating spruce trees. Species richness did not vary among forest development stages, but bird abundance was higher in recent clearcuts. Recently disturbed areas were characterized by open-land bird assemblages dominated by Neotropical migrants, which reached their highest abundance in clearcuts. Moreover, logged stands were distinguished from burned sites by the absence of cavity-nesting birds. Forest-bird assemblages reestablished themselves as soon as young spruces reached the sapling stage. However, the Black-backed Woodpecker (Picoides arcticus), Three-toed Woodpecker (Picoides tridactylus), and Brown Creeper (Certhia americana) were restricted to mature stands or recent burns and are thus likely to be negatively affected by modern forestry, which involves fire suppression and short logging rotations. We suggest that retention of larger areas of continuous mature forest might be essential to maintain these species in managed regions.
35
Tkach, Viktor, Oksana Tarnopilska, Oleksiy Kobets, Volodymyr Luk’yanets, Maksym Rumiantsev, Iryna Obolonyk, and Sergiy Musienko. "Harmfulness of root rot in the stands planted on formerly arable land and clear-cuts after annosum-infected pine forests in Chernihiv Polissya physiographic region of Ukraine." Central European Forestry Journal 66, no. 1 (March 1, 2020): 37–48. http://dx.doi.org/10.2478/forj-2019-0025.
Full textAbstract:
AbstractThe study was conducted in pure Scots pine (Pinus sylvestris L.) forests and mixed forests of Scots pine and silver birch (Betula pendula Roth.) within the Chernihiv Polissya physiographic region of Ukraine. The aim of the study was a comparative analysis of forest mensuration characteristics and health condition of pine and mixed pine-birch stands planted on formerly arable lands and cutover areas after pine stands infected by annosum root rot. It was found that in pine stands planted on formerly arable land, the average diameter of living trees in the root rot disease focus was 1–6% larger and the average diameter of dead trees was 11–23% larger than those outside the disease focus. Due to the pathological loss inside the disease foci, the pine stand density was much lower – by 14–38% and the growing stock volume was 16–35% less as compared to the outside areas. Mixed pine-birch stands (with a predominance of pine trees), established on the cutover areas after pine stands affected by root rot, had a 20% greater stock volume and the birch-pine stands (with birch predominance) in the clear-cuts had 18% greater stock volume than pure pine stands inside the root rot disease area. The pine trees were assessed as “weakened” in the mixed stands and as “severely weakened” in the pure pine stand inside the disease focus. The birch trees in mixed stands were characterized as “healthy”.
36
Mihál, Ivan, Eva Luptáková, and Martin Pavlík. "Wood-inhabiting macromycete communities in spruce stands on former agricultural land." Journal of Forest Science 67, No. 2 (February 4, 2021): 51–65. http://dx.doi.org/10.17221/107/2020-jfs.
Full textAbstract:
Wood-inhabiting macromycete (WIM) communities in the ecosystem of uneven-aged spruce stands growing on former agricultural land were investigated in relation to the supply of wood substrate, degree of wood rot, and selected climatic and ecological conditions. Altogether, 58 WIM species were detected at research plots during 2016–2018. The abundance of fruiting bodies and WIM species richness increased from the youngest to the oldest forest stands. The highest numbers of fruiting body abundance were recorded for Gymnopus perforans (11 756), Hypholoma fasciculare (2 971), Coprinellus disseminatus (326), Exidia pithya (318) and Panellus mitis (147). The influence of stand age on WIM abundance was highly significant (P < 0.001), WIM abundance was not affected by precipitation (P > 0.05). The relationships between abundance and air temperature (P < 0.001), species richness and precipitation (P < 0.001), species richness and air temperature (P < 0.001) were highly significant. The most frequent damage to trees was caused by insects and forest animals (81%), which resulted in a high occurrence of resin secretion (70%). The total volume of coarse wood debris (CWD) and the decay rate were not statistically dependent. We confirmed the occurrence of Heterobasidion annosum s.s., H. abietinum s.s., H. parviporum s.s., Armillaria ostoyae s.s. and A. cepistipes s.s. by use of molecular genetic analyses.
37
Bucha, Tomáš, Juraj Papčo, Ivan Sačkov, Jozef Pajtík, Maroš Sedliak, Ivan Barka, and Ján Feranec. "Woody Above-Ground Biomass Estimation on Abandoned Agriculture Land Using Sentinel-1 and Sentinel-2 Data." Remote Sensing 13, no. 13 (June 25, 2021): 2488. http://dx.doi.org/10.3390/rs13132488.
Full textAbstract:
Abandoned agricultural land (AAL) is a European problem and phenomenon when agricultural land is gradually overgrown with shrubs and forest. This wood biomass has not yet been systematically inventoried. The aim of this study was to experimentally prove and validate the concept of the satellite-based estimation of woody above-ground biomass (AGB) on AAL in the Western Carpathian region. The analysis is based on Sentinel-1 and -2 satellite data, supported by field research and airborne laser scanning. An improved AGB estimate was achieved using radar and optical multi-temporal data and polarimetric coherence by creating integrated predictive models by multiple regression. Abandonment is represented by two basic AAL classes identified according to overgrowth by shrub formations (AAL1) and tree formations (AAL2). First, an allometric model for AAL1 estimation was derived based on empirical material obtained from blackthorn stands. AAL2 biomass was quantified by different procedures related to (1) mature trees, (2) stumps and (3) young trees. Then, three satellite-based predictive mathematical models for AGB were developed. The best model reached R2 = 0.84 and RMSE = 41.2 t·ha−1 (35.1%), parametrized for an AGB range of 4 to 350 t·ha−1. In addition to 3214 hectares of forest land, we identified 992 hectares of shrub–tree formations on AAL with significantly lower wood AGB than on forest land and with simple shrub composition.
38
Klavina, Darta, Lauma Bruna, Astra Zaluma, Natalija Burnevica, Kaspars Polmanis, Talis Gaitnieks, and Tuula Piri. "Infection and Spread of Root Rot Caused by Heterobasidion Parviporum in Picea Abies Stands after Thinning: Case Studies on Former Pasture and Meadow Lands." Environmental Sciences Proceedings 3, no. 1 (November 12, 2020): 2. http://dx.doi.org/10.3390/iecf2020-07950.
Full textAbstract:
Afforestation of former agricultural lands is a well-established practice in several countries. It is beneficial for avoiding previous-generation forest diseases and expanding forest areas. However, several biotic and abiotic risks have been reported for such stands as well as a higher risk of Heterobasidion root rot after thinning. Therefore, this study investigates the spread patterns of Heterobasidion root rot in three Picea abies (L.) Karst. Plantations established on former pasture and meadow lands and subjected to forest management practices. First of all, to get an insight into the average infection rate we sampled all standing trees (157 in total) within a transect all along the sampling area. It showed slightly lower infection in pastures than in former meadows (16% vs. 29% and 33%, respectively). Based on those data and the observed dieback all over the stand, we established circle sample plots in disease centres where all trees and stumps were analysed, and the average infection rate there was 34–41%. All obtained Heterobasidion isolates belonging to Heterobasidion parviporum Niemelä & Korhonen. Isolates were paired to detect genotype size and infection origin. Of 141 genets examined, 99 were single-tree, indicating primary infection, and 42 formed territorial clones (160 trees and or stumps) indicating the spread of infection through root contacts. The following conclusions were reached: (i) on average, primary infection in such stands is essential, but in older stands secondary infection predominates; (ii) H. parviporum can form large (up to 137 m2) territorial clones in forests on former pasture and meadow lands causing extensive tree dieback and mortality. This study was financially supported by European Regional Development Fund’s Post-doctoral Research project No. 1.1.1.2/VIAA/2/18/298 “Determining the risk of Heterobasidion root-rot and fungal communities in roots of Norway spruce stands on former agricultural land”.
39
Rapanoela, Rija, Frédéric Raulier, Sylvie Gauthier, Hakim Ouzennou, Jean-Pierre Saucier, and Yves Bergeron. "Contrasting current and potential productivity and the influence of fire and species composition in the boreal forest: a case study in eastern Canada." Canadian Journal of Forest Research 45, no. 5 (May 2015): 541–52. http://dx.doi.org/10.1139/cjfr-2014-0124.
Full textAbstract:
The capacity of a forest stand to produce timber is related to the interactions that exist between its regeneration capacity, physical site characteristics (climate, surficial deposit, drainage), and disturbances. Minimally, to be sustainably managed, a forest needs to be sufficiently productive and able to regenerate after a disturbance so that its productive capacity is maintained or enhanced. To this effect, we evaluated timber productivity over a large area (175 000 km2) covering the latitudinal extent of closed-canopy black spruce (Picea mariana (Mill.) B.S.P) forest. Site index and relative density index were used to identify stands that cannot reach a minimum volume of trees of minimum size over one rotation. A nonparametric method was used to estimate their values for all stands within the study area. This imputation used either physical site attributes alone to assess potential productivity independent of stand history or physical and vegetation site attributes to assess current productivity. The proportion of productive stands was then estimated at the scale of landscapes ranging from 39 to 2491 km2. Physical site factors alone explain 84% of the variability in the percentage of potentially productive stands (78% for currently productive stands); their combination resulted in an abrupt transition in productivity over the study area. However, burn rate alone also explains 63% of variation in the proportion of currently productive stands and 41% of the relative difference between percentages of potentially or currently productive stands. These results have implications for strategic forest management planning at land classification stage, as timber production area is assumed to remain stable through time, whereas it is apparently related to the disturbance rate.
40
Rusdiana, Omo, and Nuri Nursjahbani. "Pemetaan Sifat Fisik dan Kimia Tanah pada Tegakan Pinus merkusii di Hutan Penelitian Dramaga, Bogor." Journal of Tropical Silviculture 11, no. 1 (April 27, 2020): 18–24. http://dx.doi.org/10.29244/j-siltrop.11.1.18-24.
Full textAbstract:
The environment is a complex system where various factors affect on the plant community in the forest. This theory should be proven by study of the influence of environmental factors to the vegetation of forest stands. This study aimed to analyze the effect of environmental factors, particularly edaphic factors such as soil physical and chemical properties to the vegetation and to examine the effect of edaphic variations to the vegetation variation of Pinus merkusii stands on the plot of 163, Dramaga Forest Research, Bogor. The sample of soil were disturbed sample and undisturbed sample taken by systematic sampling method. There was a tendency that the greater the properties of soil the better the vegetation growth in terms of height and diameter of pine tree. However, that effect was not significant due to the great durability of P. merkusii against marginal soil condition. The soil properties must be supported by other factors such as shading so that the two factors are able to manage the optimal growth of pine trees and maintain the function of forest.
Keywords: Pinus merkusii, physical properties, chemical properties, land unit, Dramaga
41
Nunes, Leónia, Mauro Moreno, Iciar Alberdi, Juan Gabriel Álvarez-González, Paulo Godinho-Ferreira, Stefano Mazzoleni, and Francisco Castro Rego. "Harmonized Classification of Forest Types in the Iberian Peninsula Based on National Forest Inventories." Forests 11, no. 11 (November 2, 2020): 1170. http://dx.doi.org/10.3390/f11111170.
Full textAbstract:
National Forest Inventories (NFIs) collect and provide a large amount of information regarding the forest volume, carbon stocks, vitality, biodiversity, non-wood forest products and their changes. Forest stands variables data are paramount to understanding their composition, especially on those related with understory characteristics and the coverage of species according to canopy layers; they are essential to assess biodiversity and to support forest management. At the same time, these inventories allow the development of harmonized forest descriptions beyond the national scale. This study aims to develop a homogeneous characterization of the Iberian Peninsula’s forests, in order to classify and identify the forest types. For this purpose, harmonized data from NFIs of Portugal and Spain were used to assess the composition of species, dominance and the percentage of cover for each species in a vertical space defined by seven canopy layers. Using the “K-means” clustering algorithm, a set of clusters was identified and georeferenced using forest polygons from land use and cover maps of both countries. The interpretation and description of the clusters lead to the establishment of 28 forest types that characterize all of the Iberian Peninsula forests. Each forest area has been described through one of the forest types and their relation with other ecological characteristics of the stands was analyzed. Shrubs formations are generally widely distributed in the forest area of the Iberian Peninsula, however their abundance in terms of cover is lower in comparison with tree species. Around 71% of the forest types are dominated by trees, mainly species from the genera Pinus and Quercus, and 21% are dominated by shrub formations with species of Ulex spp., Cytisus spp., and Cistus spp. The Quercus ilex s.l. L. and Pinus pinaster Aiton are the common species of importance for both NFIs. The results represent a powerful and homogenous multi-use tool describing the Iberian Peninsula’s forestlands with applications on landscape analysis, forest management and conservation. This information can be used for comparisons at larger scales, allowing cross-border analysis in relation to various aspects, such as hazards and wildfires, as well as management and conservation of forest biodiversity. The developed method is adaptable to an updated dataset from more recent NFIs and to other study areas.
42
Gorrod, E. J., P. Childs, D. A. Keith, S. Bowen, M. Pennay, T. O'Kelly, R. Woodward, A. Haywood, J. P. Pigott, and C. McCormack. "Can ecological thinning deliver conservation outcomes in high-density river red gum forests? Establishing an adaptive management experiment." Pacific Conservation Biology 23, no. 3 (2017): 262. http://dx.doi.org/10.1071/pc16040.
Full textAbstract:
Newly protected areas often have land-use legacies that affect their capacity to deliver conservation outcomes into the future. The management actions required to achieve conservation outcomes may be uncertain. This uncertainty may be resolved through experimental adaptive management that draws on knowledge of the ecology and history of the ecosystem. In New South Wales, Australia, river red gum (Eucalyptus camaldulensis) floodplain forests were gazetted as National Park in 2010, including Murray Valley National Park. Land-use legacies had resulted in one-third of river red gum forests and woodlands occurring as high-stem-density (>400 stems ha−1) stands at the time of gazettal. High-stem-density stands are characterised by dominance of narrow straight trees, a paucity of large and hollow-bearing trees, modified understorey vegetation and reduced coarse woody debris. A simple state-and-transition process model captured knowledge of the processes that led to the high-stem-density river red gum forest state being widespread. We describe the establishment of a manipulative experiment to evaluate whether ecological thinning can achieve conservation outcomes in high-stem-density stands of river red gum floodplain forest. The experiment was designed to reduce intrastand competition for water and other resources, and encourage development of spreading tree crowns. Future results will inform management decisions in high-stem-density stands of river red gum floodplain forests. The adaptive management approach employed provides a template for using knowledge of the ecosystem to resolve uncertainty about management, particularly in newly protected areas.
43
Morin, Randall S., Andrew M. Liebhold, and Kurt W. Gottschalk. "Area-Wide Analysis of Hardwood Defoliator Effects on Tree Conditions in the Allegheny Plateau." Northern Journal of Applied Forestry 21, no. 1 (March 1, 2004): 31–39. http://dx.doi.org/10.1093/njaf/21.1.31.
Full textAbstract:
Abstract The effects of defoliation caused by three foliage feeding insects, the gypsy moth (Lymantria dispar), the cherry scallopshell moth (Hydria prunivorata), and the elm spanworm (Ennomos subsignarius), on tree mortality and crown conditions were evaluated using data collected from 1984 to 1999 in the Allegheny National Forest located in northwestern Pennsylvania. While previous studies have focused on the effects of defoliation on trees in individual stands, this study differed in that it used exhaustive maps of defoliation and an areawide network of plots to assess these effects. A geographic information system was used to map the coincidence of USDA Forest Service Forest Inventory and Analysis and Forest Health Monitoring plot locations with defoliation polygons derived from aerial surveys to calculate cumulative years of defoliation for each pest. Over 85% of the Allegheny National Forest land area was defoliated at least once during the 16-year period from 1984 to 1999. Frequency of defoliation by specific defoliator species was closely associated with the dominance of their primary hosts in stands. Frequency of defoliation was often associated with crown dieback and mortality, but these relationships were not detectable in all species. These results suggest that when impacts are averaged over large areas (such as in this study) effects of defoliation are likely to be considerably less severe than when measured in selected stands (as is the approach taken in most previous impact studies).
44
Данилов, Dmitriy Danilov, Беляева, Nataliia Beliaeva, Мартынов, Aleksey Martynov, Зайцев, and Dmitriy Zaytsev. "THE IMPACT OF SHARE PARTICIPATION OF PINE AND SPRUCE ON INVENTORY INDICES OF MIXED FOREST STANDS." Forestry Engineering Journal 7, no. 1 (August 15, 2017): 49–58. http://dx.doi.org/10.12737/25192.
Full textAbstract:
The influence of composition on the dynamics of inventory indices of the mixed modal forest stands is considered: ridges with the groups of forest types of middle subzone of taiga in the territory of the Leningrad region, for 60 year period. The course of growth of pine and spruce in the mixed stand is due to the composition of the stand, which affects the entire life cycle of its development. Analysis of forest inventory data at the test plots has shown that the median line for the average height and diameter has the distinction of growth from tabular reference data. Differences in the dynamics of growth in valuation metrics over the study period is due to the initial density of pine, then spruce, and the degree of difference in the age of trees. The variability of average heights and diameters on the experimental plots is influenced by the share of particular species in the composition of the stand. The stand composition significantly affects average diameter and height of tiers, composing the mixed coniferous forest that was confirmed by single-factor analysis of variance. The sum of the areas of the cross sections at the pine tier of the virtually at all experienced objects increases up to the age of 100-120 years, and in spruce this dependence is shown only up to the age of 80-85 years. Pine tier depending on the initial density has a greater impact on the composition of the mixed stands than spruce. This can be considered as a fact of environmental compliance of the conditions of the types: ridges with groups of forest types, for successful growth of pine. In mixed stands, untouched by commercial logging, the spruce element, quantitatively not exceeding the pine one, are stunted and produce less stock
45
Kronholm, Thomas, David Bengtsson, and Dan Bergström. "Family Forest Owners’ Perception of Management and Thinning Operations in Young Dense Forests: A Survey from Sweden." Forests 11, no. 11 (October 30, 2020): 1151. http://dx.doi.org/10.3390/f11111151.
Full textAbstract:
Family forest owners (FFOs) own 48% of Sweden’s productive forest land and are responsible for 59% of the annual gross felling. They are thus important suppliers of raw materials to the forest industry and the energy sector. Environmental goals on the national and international level promote an increased use of renewable resources in order to replace fossil-based fuels, but since the current supply of forest products is already fully utilized by the industry, there is a need to find new types of biomass assortment. One way to increase the biomass supply is to replace traditional pre-commercial thinning operations, where fallen stems are left in the forest to rot, with whole-tree harvesting of small-diameter trees using novel technologies and methods. This will however require willingness of the FFOs to shift their management practices. The objectives of this study were, therefore, to elucidate FFOs’ perceptions of management and thinning operations in young dense forests, identify if there are differences depending on their demographic backgrounds, and clarify which factors could potentially affect their willingness to implement whole-tree harvesting in young dense forests. Data were collected through a survey administered to a random sample of 842 FFOs, with a response rate of 53.4% (n = 450). The results show that FFOs in general are positive towards implementing whole-tree harvesting in young dense stands, and are often also willing to promote the development of suitable stands. Factors such as forest size, geographical location, distance from home to their forest, degree of self-employment and current need for cleaning were found to significantly affect their attitudes. The study highlights that the development of cost efficient harvesting techniques and working methods is important if the industry wants to increase the FFOs’ willingness to engage in whole-tree harvesting in young dense forest stands and thereby increase the supply of biomass.
46
Cannon, Jeffery B., Wade T. Tinkham, Ryan K. DeAngelis, Edward M. Hill, and Mike A. Battaglia. "Variability in Mixed Conifer Spatial Structure Changes Understory Light Environments." Forests 10, no. 11 (November 13, 2019): 1015. http://dx.doi.org/10.3390/f10111015.
Full textAbstract:
In fire-adapted conifer forests of the Western U.S., changing land use has led to increased forest densities and fuel conditions partly responsible for increasing the extent of high-severity wildfires in the region. In response, land managers often use mechanical thinning treatments to reduce fuels and increase overstory structural complexity, which can help improve stand resilience and restore complex spatial patterns that once characterized these stands. The outcomes of these treatments can vary greatly, resulting in a large gradient in aggregation of residual overstory trees. However, there is limited information on how a range of spatial outcomes from restoration treatments can influence structural complexity and tree regeneration dynamics in mixed conifer stands. In this study, we model understory light levels across a range of forest density in a stem-mapped dry mixed conifer forest and apply this model to simulated stem maps that are similar in residual basal area yet vary in degree of spatial complexity. We found that light availability was best modeled by residual stand density index and that consideration of forest structure at multiple spatial scales is important for predicting light availability. Second, we found that restoration treatments differing in spatial pattern may differ markedly in their achievement of objectives such as density reduction, maintenance of horizontal and tree size complexity, and creation of microsite conditions favorable to shade-intolerant species, with several notable tradeoffs. These conditions in turn have cascading effects on regeneration dynamics, treatment longevity, fire behavior, and resilience to disturbances. In our study, treatments with high aggregation of residual trees best balanced multiple objectives typically used in ponderosa pine and dry mixed conifer forests. Simulation studies that consider a wide range of possible spatial patterns can complement field studies and provide predictions of the impacts of mechanical treatments on a large range of potential ecological effects.
47
Prasmatiwi, Fembriarti Erry, Irham Irham, Any Suryantini, and Jamhari Jamhari. "KESEDIAAN MEMBAYAR PETANI KOPI UNTUK PERBAIKAN LINGKUNGAN." Jurnal Ekonomi Pembangunan: Kajian Masalah Ekonomi dan Pembangunan 12, no. 2 (December 1, 2011): 187. http://dx.doi.org/10.23917/jep.v12i2.192.
Full textAbstract:
This study aims were, first to measure the level of farmers’ willingness to pay the external cost to improve the environment and second, examine the determinant factors. The experiment was conducted in District Sumberjaya and Sekincau, West Lampung District during June-October 2009. Contingent Valuation Method (CVM) was used to answer the first purpose, while ordinal logit regression analysis was used to answer the second purpose. Factors of farmland area, land productivity, household income, educational level, number of family labor, and knowledge of farmers about the benefits of forests had positive influence on WTP while distance of farmers’ house to the forest had negative influence. The increase of WTP was needed to reduce environmental damage due to forest conversion to coffee plantation; moreover, environment improvement hopefully could restore the function of forest where coffee trees were planted.
48
Wojda, Tomasz, Marcin Klisz, Szymon Jastrzębowski, Marcin Mionskowski, Iwona Szyp-Borowska, and Krystyna Szczygieł. "The Geographical Distribution Of The Black Locust (Robinia Pseudoacacia L.) In Poland And Its Role On Non-Forest Land." Papers on Global Change IGBP 22, no. 1 (January 1, 2015): 101–13. http://dx.doi.org/10.1515/igbp-2015-0018.
Full textAbstract:
AbstractThe black locust (Robinia pseudoacaciaL.) has been present in Poland for more than 200 years now, its range coming to encompass the entire country, albeit with a particular concentration of occurrence in the west. Overall, it is present in 3.4% of the stands making up Poland’s “State Forests National Forest Holding” (Państwowe Gospodarstwo Leśne Lasy Państwowe), and is the dominant species in 0.1% of stands. Thanks to its producing durable wood of favourable energetic properties, this species is used in medium-rotation (≤ 40-year) plantations as well as in biomass energy plantations (where there is a 5–7-year rotation). In terms of its nectar production, the black locust is second only to lime as the Polish tree best serving the production of honey. While the species shows marked expansiveness in Poland, it has not thus far been placed on the list of aliens capable of threatening native species or natural habitats. Breeding of the species has been engaged in – if to only a limited extent – in Poland for some 20 years now, and 2 selected seed stands have been registered, as well as 34 plus trees and 2 seed orchards.
49
Burton, Philip J., Daniel D. Kneeshaw, and K. David Coates. "Managing forest harvesting to maintain old growth in boreal and sub-boreal forests." Forestry Chronicle 75, no. 4 (August 1, 1999): 623–31. http://dx.doi.org/10.5558/tfc75623-4.
Full textAbstract:
Old-growth stands can be rare in northern coniferous forests, and hence are worthy of protection and special management. We describe some quantitative guidelines for recognizing old-growth stands and options for maintaining a long-term supply of old-growth values in landscapes managed for timber production. In the Sub-Boreal Spruce forests of central British Columbia, attributes most indicative of old-growth status include stand age, the density of large (> 1.0 m3) snags and downed logs, stand basal area and volume. It is suggested that partial cutting could occur in some old-growth stands, while still maintaining their structural and functional attributes, if large logs, snags and trees are retained at the threshold densities necessary to recognise old-growth status. At the landscape level, the use of extended timber crop rotations is advocated. Planning for a tapered forest age class distribution (with decreasing areas of forest allowed to persist to successively older ages) is suggested as a means of sustainably generating true old-growth, and as an alternative to the use of partial cutting and patch retention. Arithmetic formulas are developed which provide guidelines for the proportion of the forest land base to be kept in each successive age class. This model for regulating human disturbance in commercial forests holds promise as a mechanism for allowing continued timber harvest and even-aged stand management while retaining a near-natural proportion of old-growth forest in northern landscapes. Key words: disturbance regime, even-aged management, extended rotations, forest age class structure, forest management, old-growth attributes, rotation length, silvicultural systems, sub-boreal spruce zone, timber supply planning.
50
Bowman, DMJS. "Environmental Determinants of Allosyncarpia ternata Forests That Are Endemic to Western Arnhem Land, Northern Australia." Australian Journal of Botany 39, no. 6 (1991): 575. http://dx.doi.org/10.1071/bt9910575.
Full textAbstract:
Allosyncarpia ternata S. T. Blake dominates closed forests on rugged sandstone escarpments on the western edge of the Arnhem Land Plateau, northern Australia. The forests occur in a floristic continuum between fire-protected wet monsoon forests in the base of canyons and frequently burnt, eucalyptdominated savannas that occur in all other topographic positions. An indirect gradient analysis of 69 quadrats from these three vegetation types at six different localities showed that no measured edaphic variable was correlated with this floristic transition. A detailed study of a single patch of Allosyncarpia on level terrain with rock-free, sandy soils showed that Allosyncarpia trees occur on sites with significantly deeper soils and higher concentrations of available K in the surface soil compared to surrounding eucalypt savannas. However, there was no significant difference in dry season surface soil moisture content between these communities. There is also evidence that there is no significant difference in subsoil moisture supply. Xylem pressure potential of Callitris intratropica (which is equally abundant in both Allosyncarpia and eucalypt communities) was found to be statistically similar at the beginning and end of the dry season. The Allosyncarpia forest was made up of a mosaic ranging from stands co-dominated by savanna species with grassy understoreys to stands co-dominated by monsoon forest species with dense understoreys. No measured environmental factors were significantly related to the patterning of these stands within the forest. Seed throw of Allosyncarpia is limited to several metres from the canopy edge and seedlings were only observed beneath the canopy. Field experiments demonstrated that seedling survival in the savanna can be enhanced by the provision of shade, and nursery experiments demonstrated that the growth of seedlings provided with ample water is suppressed by full sunlight. Dry season fires in grass fuels ranging from 2 to 8 t ha-1 were found to be lethal to seedlings <100 mm tall. Although most Allosyncarpia trees recover following fire damage, the present distribution of the species may be best explained as a consequence of wildfires. However, there is need for confirmation that the species range is contracting under current fire regimes. This is probably best derived by analysis of existing remote sensing data.