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Journal articles on the topic 'Stand Biomass'
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1
Yang, Bin, Wenyan Xue, Shichuan Yu, Jianyun Zhou, and Wenhui Zhang. "Effects of Stand Age on Biomass Allocation and Allometry of Quercus Acutissima in the Central Loess Plateau of China." Forests 10, no. 1 (January 9, 2019): 41. http://dx.doi.org/10.3390/f10010041.
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We studied the effects of stand age on allocation and equation fitting of aboveground and below-ground biomass in four Quercus acutissima stands (14, 31, 46, and 63 years old) in the Central Loess Plateau of China. The stem wood, stem bark, branch, foliage, and belowground biomass of each of the 20 destructive harvesting trees were quantified. The mean total biomass of each tree was 28.8, 106.8, 380.6, and 603.4 kg/tree in the 14-, 31-, 46-, and 63-year-old stands, respectively. Aboveground biomass accounted for 72.25%, 73.05%, 76.14%, and 80.37% of the total tree biomass in the 14-, 31-, 46-, and 63-year-old stands, respectively, and stem wood was the major component of tree biomass. The proportion of stem (with bark) biomass to total tree biomass increased with stand age while the proportions of branch, foliage, and belowground biomass to total tree biomass decreased with stand age. The ratio of belowground biomass to aboveground biomass decreased from 0.39 in the 14-year-old stand to 0.37, 0.31, and 0.24 in the 31-, 46-, and 63-year-old stands, respectively. Age-specific biomass equations in each stand were developed for stem wood, stem bark, aboveground, and total tree. The inclusion of tree height as a second variable improved the total tree biomass equation fitting for middle-aged (31-year-old and 46-year-old) stands but not young (14 years old) and mature (63 years old) stands. Moreover, biomass conversion and expansion factors (BCEFs) varied with stand age, showing a decreasing trend with increasing stand age. These results indicate that stand age alters the biomass allocation of Q. acutissima and results in age-specific allometric biomass equations and BCEFs. Therefore, to obtain accurate estimates of Q. acutissima forest biomass and carbon stocks, age-specific changes need to be considered.
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Dutcă, Ioan, Richard Mather, and Florin Ioraş. "Tree biomass allometry during the early growth of Norway spruce (Picea abies) varies between pure stands and mixtures with European beech (Fagus sylvatica)." Canadian Journal of Forest Research 48, no. 1 (January 2018): 77–84. http://dx.doi.org/10.1139/cjfr-2017-0177.
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In this paper, we report an investigation of how forest stand mixture may affect biomass allometric relationships in Norway spruce (Picea abies (L.) Karst.). Analysis of aboveground biomass data was conducted for 50 trees: 25 sample trees from a pure Norway spruce stand and 25 from a mixed stand of Norway spruce with European beech (Fagus sylvatica L.). ANCOVA results demonstrated that individual-tree biomass allometry of the pure stand significantly differed from that of the mixed stand. Allometric characteristics depended on the biomass component recorded and the type of biomass predictor used. When predicted by diameter at breast height and (or) height, the total aboveground biomass of mixed-stand trees was significantly less than that for pure-stand trees. This “apparent” lower aboveground biomass was attributed to the lower branch and needle biomass proportions of trees growing in mixed stand. The findings indicate that caution should be exercised when applying biomass allometric models developed from pure stands to predict tree biomass in mixed stands (and vice versa), as such data treatment may introduce significant bias.
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Jagodziński, Andrzej, Marcin Dyderski, Kamil Gęsikiewicz, and Paweł Horodecki. "Tree- and Stand-Level Biomass Estimation in a Larix decidua Mill. Chronosequence." Forests 9, no. 10 (September 21, 2018): 587. http://dx.doi.org/10.3390/f9100587.
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Carbon pool assessments in forests is one of the most important tasks of forest ecology. Despite the wide cultivation range, and economical and traditional importance, the aboveground biomass of European larch (Larix decidua Mill.) stands is poorly characterized. To increase knowledge about forest biomass accumulation and to provide a set of tools for aboveground biomass estimation, we studied a chronosequence of 12 larch forest stands (7–120 years old). From these stands, we measured the biomass of 96 sample trees ranging from 1.9 to 57.9 cm in diameter at breast height. We provided age-specific and generalized allometric equations, biomass conversion and expansion factors (BCEFs) and biomass models based on forest stand characteristics. Aboveground biomass of stands ranged from 4.46 (7-year-old forest stand) to 445.76 Mg ha−1 (106-year-old). Stand biomass increased with increasing stand age, basal area, mean diameter, height and total stem volume and decreased with increasing density. BCEFs of the aboveground biomass and stem were almost constant (mean BCEFs of 0.4688 and 0.3833 Mg m−3, respectively). Our generalized models at the tree and stand level had lower bias in predicting the biomass of the forest stands studied, than other published models. The set of tools provided fills the gap in biomass estimation caused by the low number of studies on larch biomass, which allows for better estimation of forest carbon pools.
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Lee, E. Henry, David T. Tingey, Peter A. Beedlow, Mark G. Johnson, and Robert B. McKane. "A spatial analysis of fine-root biomass from stand data in the Pacific Northwest." Canadian Journal of Forest Research 34, no. 10 (October 1, 2004): 2169–80. http://dx.doi.org/10.1139/x04-098.
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High spatial variability of fine roots in natural forest stands makes accurate estimates of stand-level fine-root biomass difficult and expensive to obtain by standard coring methods. This study uses aboveground tree metrics and spatial relationships to improve core-based estimates of stand-level fine-root biomass. Using the multiple-tree Ribbens model for pure stands, the approach assumes that the total fine-root biomass at a given point is the additive contribution of the nearest dominant trees and that fine-root biomass for a single tree depends on the distance to the trunk and its size. A Monte Carlo random sampling technique, or sampling on a regular grid, is used to estimate the average fine-root biomass across the stand. We illustrate the applicability of this approach by using it on root-core data from a Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stand and a western juniper (Juniperus occidentalis Hook.) stand in the Pacific Northwest. We conclude that stand-level fine-root biomass is adequately estimated using the Ribbens model. Unlike the model-based estimate for stand-level fine-root biomass, the accuracy and precision of the arithmetic mean of the coring samples depends on the spatial heterogeneity of root distributions and the representativeness of the root coring samples.
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Espinosa Bancalari, Miguel A., and David A. Perry. "Distribution and increment of biomass in adjacent young Douglas-fir stands with different early growth rates." Canadian Journal of Forest Research 17, no. 7 (July 1, 1987): 722–30. http://dx.doi.org/10.1139/x87-115.
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Total biomass increments were determined for three adjacent 22-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) plantations in the Oregon Coast Range that had widely different early growth rates. Estimated total aboveground biomass of the stands, designated slow, intermediate, and fast, was 98.7, 148.7, and 203.7 Mg•ha−1, respectively; estimated mean biomass increment in the 5 years previous to sampling was 8.9, 12.6, and 12.3 Mg•ha−1•year−1. The slow stand had a greater proportion of aboveground biomass in branches and a smaller proportion in stem wood than the intermediate and fast stands. Differences in biomass increment were primarily due to stem rather than crown growth. Total below ground biomass was highest in the fast stand, the difference being due to roots >5 mm in diameter; weight of roots <5 mm was greater in the slow and intermediate stands. Roots >5 mm comprised about 77% of the total root system in those stands and 90% in the fast stand. Increment of roots >5 mm was 2.2, 2.5, and 3.0 Mg•ha−1•year−1 in the slow, intermediate, and fast stands. The ratio of productivity to total leaf nitrogen suggests that nitrogen is a principal limiting resource in the intermediate stand. The fast stand, with a leaf area index 50% greater than the others, is probably limited by light. The slow stand has anaerobic soils during at least part of the year, which may restrict rooting depth and thereby induce water stress during summer drought.
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Špulák, Ondřej, Jiří Souček, and Jakub Černý. "Do stand structure and admixture of tree species affect Scots pine aboveground biomass production and stability on its natural site?" Journal of Forest Science 64, No. 11 (December 3, 2018): 486–95. http://dx.doi.org/10.17221/117/2018-jfs.
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The paper analyses stand structure and production on two experimental forest stand series of mature pure and mixed Scots pine stands, growing on natural Scots pine sites in the Czech Republic. Sessile oak was the main admixed species. In mixed stands, Scots pine constituted the dominant level of the stand, admixed species grew mostly as subdominants. Admixture increased stand densities and aboveground biomass production compared to pure stands. Sessile oak with the 20–30% number share within the Scots pine stand led to an increase of the Scots pine tree dimensions and mean stem merchantable wood (DBH ≥ 7 cm) volume compared to the pure Scots pine stand of similar density. The Scots pine and sessile oak slenderness ratios increased in mixed stands compared to monocultures, however, the stand mechanical stability was not threatened.
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Adams, J. C., and B. G. Lockaby. "Variability of Understory Sweetgum Biomass Relationships." Southern Journal of Applied Forestry 12, no. 1 (February 1, 1988): 5–7. http://dx.doi.org/10.1093/sjaf/12.1.5.
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Abstract Understory sweetgum (Liquidambar styraciflua L.) in three 40-50-yr-old stands of loblolly pine was sampled to estimate the total and component biomass encompassed by this species. Individual tree sweetgum equations (based on D²H) were developed for total tree and tree component biomass for each stand. Total stand estimates of 9.79, 8.38, 1.09, and 0 32 tons/ac were determined for total, stem, branch, and foliage dry weight, respectively. There were no statistical differences among stands for total tree and stem biomass equations, but differences were found among stands for foliage and branch equations. The differences among crown component equations are probably reflective of the understory growing conditions in the different stands. South. J. Appl. For. 12(1):5-7.
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McDowell, Nate G., Nick J. Balster, and John D. Marshall. "Belowground carbon allocation of Rocky Mountain Douglas-fir." Canadian Journal of Forest Research 31, no. 8 (August 1, 2001): 1425–36. http://dx.doi.org/10.1139/x01-067.
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Carbon allocation to fine roots and mycorrhizae constitute one of the largest carbon fluxes in forest ecosystems, but these fluxes are also among the most difficult to measure. We measured belowground carbon fluxes in two Pseudotsuga menziesii (Mirb.) Franco var. glauca stands. We used a carbon balance approach to estimate total belowground carbon allocation (TBCA) and carbon allocation to fine-root and mycorrhizal production (NPPfr). The stands differed in belowground biomass because of fertilization treatment 8 years prior. Annual soil flux was 856 and 849 g C·m2·year1 for the two stands. Annual root respiration equaled 269 and 333 g C·m2·year1 in the low- and high-biomass stand, respectively. TBCA equaled 733 and 710 g C·m2·year1 in the low- and high-biomass stand, respectively. Calculated NPPfr equaled 431 g C·m2·year1 in the low-biomass stand and 334 g C·m2·year1 in the high-biomass stand; equivalent to 59 and 47% of TBCA, respectively. Fine-root and mycorrhizal turnover equaled 1.8 and 0.8 year1 in the low- and high-biomass stands, respectively. Belowground carbon allocation appeared to be distributed evenly between respiration and production despite differences in biomass and turnover. Sensitivity analysis indicated the NPPfr estimate is dependent foremost on the annual prediction of soil CO2 flux. The carbon balance approach provided a simple nonintrusive method for separating the belowground autotrophic and heterotrophic carbon budget.
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Wu, Zhou, Wen, Zhu, You, Qin, Li, et al. "Coniferous-Broadleaf Mixture Increases Soil Microbial Biomass and Functions Accompanied by Improved Stand Biomass and Litter Production in Subtropical China." Forests 10, no. 10 (October 6, 2019): 879. http://dx.doi.org/10.3390/f10100879.
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Although the advantages of multi-species plantations over single-species plantations have been widely recognized, the mechanisms driving these advantages remain unclear. In this study, we compared stand biomass, litter production and quality, soil properties, soil microbial community, and functions in a Pinus massoniana Lamb. and Castanopsis hystrix Miq. mixed plantation and their corresponding mono-specific plantations after 34 years afforestation in subtropical China. The results have shown that a coniferous-broadleaf mixture created significantly positive effects on stand biomass, litter production, soil microbial biomass, and activities. Firstly, the tree, shrub and herb biomass, and litter production were significantly higher in the coniferous-broadleaf mixed plantation. Secondly, although the concentrations of soil organic carbon (SOC) and total nitrogen (TN) were lower in the mixed stand, the concentrations of soil microbial biomass carbon (MBC), and nitrogen (MBN), along with MBC-to-SOC and MBN-to-TN ratio, were significantly higher in mixed stands with markedly positive admixing effects. We also found higher carbon source utilization ability and β−1, 4−N−acetylglucosaminidase, urease and acid phosphatase activities in mixed stands compared with the mono-species stands. Our results highlight that establishment of coniferous-broadleaf mixed forests may be a good management practice as coniferous-broadleaf mixture could accumulate higher stand biomass and return more litter, resulting in increasing soil microbial biomass and related functions for the long term in subtropical China.
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Uri, Veiko, Jürgen Aosaar, Mats Varik, and Merit Kund. "The growth and production of some fast growing deciduous tree species stands on abandoned agricultural land." Forestry Studies / Metsanduslikud Uurimused 52, no. 1 (January 1, 2010): 18–29. http://dx.doi.org/10.2478/v10132-011-0080-z.
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Mõningate kiirekasvuliste lehtpuupuistute kasv ja produktsioonivõime endisel põllumaalSeveral studies about stands growing on abandoned agricultural lands are induced by extensive afforestation of agricultural lands and more intensive use of biomass. Overview of above-ground biomass production of grey alder, hybrid alder and silver birch young stands growing on former agricultural areas are presented in current paper. The results of 16- and 6-year period of alders and silver birch stands, respectively, are reported. Above-ground biomass and biomass production of stands were estimated. The growing stock and current annual increment (CAI) of 16-years-old grey alder stand were 250 m3ha-1and 35.6 m3ha-1, respectively. Due to fast growth and high biomass production capacity grey alder is promising tree species for short-rotation forestry in Estonia. Hybrid alder is productive tree although not exceeding the productivity of grey alders. Stem volume and CAI of the 16-years-old hybrid alder stand were 155 m3ha-1and 21 m3ha-1, respectively. Our results supported earlier data reported in literature: rotation period of hybrid alder is longer than for grey alder and CAI of hybrid alder stands culminate later. The productivity of young silver birch stands on abandoned agricultural land is varying in a broad range. One young silver birch stand growing on abandoned agricultural land was involved into study. Growing stock and CAI in 13-years old stand were 118 m3ha-1and 15 m3ha-1, respectively. These values are exceeding respective values of several yield tables of silver birch and biomass production capability of silver birch stands in favourable conditions is high.
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Fatemi, Farrah R., Ruth D. Yanai, Steven P. Hamburg, Matthew A. Vadeboncoeur, Mary A. Arthur, Russell D. Briggs, and Carrie R. Levine. "Allometric equations for young northern hardwoods: the importance of age-specific equations for estimating aboveground biomass." Canadian Journal of Forest Research 41, no. 4 (April 2011): 881–91. http://dx.doi.org/10.1139/x10-248.
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Estimates of aboveground biomass and nutrient stocks are commonly derived using equations that describe tree dimensional relationships. Despite the widespread use of this approach, there is little information about whether equations specific to stand age are necessary for accurate biomass predictions. We developed equations for small trees (2–12 cm diameter) of six species in four young northern hardwood stands. We then compared our equations with equations used frequently in the literature that were developed in mature stands (Whittaker et al. 1974. Ecol. Monogr. 44: 233–252). Our equations for yellow birch ( Betula alleghaniensis Britt.) predicted 11%–120% greater stem wood for individual trees compared with the equations from Whittaker et al. and, on average, 50% greater aboveground yellow birch biomass in the four stands that we studied. Differences were less pronounced for sugar maple ( Acer saccharum Marsh.) and American beech ( Fagus grandifolia Ehrh.); our equations predicted, on average, 9% greater aboveground stand biomass for sugar maple and 3% lower biomass for American beech compared with Whittaker et al. Our results suggest that stand age may be an important factor influencing the aboveground allometry and biomass of small yellow birch trees in these developing northern hardwood stands.
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Will, Rodney E., Gregory T. Munger, Yujia Zhang, and Bruce E. Borders. "Effects of annual fertilization and complete competition control on current annual increment, foliar development, and growth efficiency of different aged Pinus taeda stands." Canadian Journal of Forest Research 32, no. 10 (October 1, 2002): 1728–40. http://dx.doi.org/10.1139/x02-095.
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The effects that competing vegetation and nitrogen limitation have on the current annual increment (CAI), leaf biomass, and growth efficiency (GE) of different aged loblolly pine (Pinus taeda L.) stands planted on a Piedmont and lower Coastal Plain location in Georgia, U.S.A. were determined by measuring stands receiving a factorial combination of complete interspecific competition control and annual nitrogen fertilization. At the Piedmont location, CAI increased with age (5, 10, and 12 years) as well as fertilization (7.39.2 Mg·ha1) and competition control (6.89.6 Mg·ha1). The effects of fertilization on leaf biomass increased with stand age (no difference at age 5 to 1.5 Mg·ha1 difference at age 12), while the effects of competition control on leaf biomass decreased with stand age (difference of 2.5 Mg·ha1 at age 5 to difference of 1.6 Mg·ha1 at age 12). At the Coastal Plain location, fertilization increased CAI from 10.3 to 14.8 Mg·ha1. Leaf biomass increased with competition control (4.95.5 Mg·ha1) and fertilization (4.46.0 Mg·ha1). Leaf biomass increased with stand age for the fertilized stands (5.37.0 Mg·ha1 between age 7 and 13) and decreased with stand age for nonfertilized stands (4.94.0 Mg·ha1 between age 7 and 13). At the Coastal Plain location, fertilization increased the GE of the age-7 stands from 2.34 to 2.86 but decreased the GE of the age-13 stands from 2.32 to 2.14. In general, GE decreased as mean tree size increased indicating that changes in GE related to treatments may be confounded with changes in tree size. Results of this experiment emphasize the importance of nutrition on stand growth as fertilization increased leaf biomass and may increase stem production per unit of foliage at early stages of development.
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Tinker, Daniel, Gail K. Stakes, and Richard M. Arcano. "Allometric Equation Development, Biomass, and Aboveground Productivity in Ponderosa Pine Forests, Black Hills, Wyoming." Western Journal of Applied Forestry 25, no. 3 (July 1, 2010): 112–19. http://dx.doi.org/10.1093/wjaf/25.3.112.
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Abstract Temperate forest ecosystems continue to play an important role in the global carbon cycle, and the ability to accurately quantify carbon storage and allocation remains a critical tool for managers and researchers. This study was aimed at developing new allometric equations for predicting above- and belowground biomass of both mature trees and saplings of ponderosa pine trees in the Black Hills region of the western United States and at evaluating thinning effects on biomass pools and aboveground productivity. Study sites included three stands that had been commercially thinned and one unmanaged stand. Nine allometric equations were developed for mature trees, and six equations were developed for saplings; all models exhibited strong predictive power. The unmanaged stand contained more than twice as much total aboveground biomass as any of the thinned stands. Aboveground biomass allocation among tree compartments was similar among the three older stands but quite different from the young, even-aged stand. Stand-level aboveground net primary production was higher in the unmanaged and intensively managed stands, yet tree-level annual productivity was much lower in the unmanaged stands than in any of the managed forests, suggesting that thinning of some forest stands may increase their ability to sequester and store carbon. Our data also suggest that different management approaches did not have the same effect on carbon allocation as they did on total carbon storage capacity, but rather, stand age was the most important factor in predicting carbon allocation within individual trees and stands. Identification of the relationships between stand structure and forest management practices may help identify various management strategies that maximize rates of carbon storage in ponderosa pine forests.
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Grewal, H. "Parent stand age and harvesting treatment effects on juvenile aspen biomass productivity." Forestry Chronicle 71, no. 3 (June 1, 1995): 299–303. http://dx.doi.org/10.5558/tfc71299-3.
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The objectives of this study were to characterize parent stand age and harvest method treatment effects on biomass production of aspen and other species, and to construct equations for the prediction of aspen stemwood, branch, and foliage biomass production. Aspen from young parent stands (30–40 years) generally regenerated taller and denser stands, and produced higher total aspen biomass and larger proportions of branch biomass than those regenerated from older parent stands. Stands regenerated after total biomass removal were taller and had larger diameters and average densities than stands regenerated by conventional logging. Aspen biomass component production was predicted consistently by various combinations and transformations of height and diameter. Key words: aspen, biomass equations, biomass production, harvest method, logging method, parent age
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Wertz, Bogdan, Mariusz Bembenek, Zbigniew Karaszewski, Wojciech Ochał, Maciej Skorupski, Paweł Strzeliński, Andrzej Węgiel, and Piotr S. Mederski. "Impact of Stand Density and Tree Social Status on Aboveground Biomass Allocation of Scots Pine Pinus sylvestris L." Forests 11, no. 7 (July 17, 2020): 765. http://dx.doi.org/10.3390/f11070765.
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Stand density changes due to aging and thinning interventions. At the same time, the social status of trees develops and varies due to different genetic conditions as well as access to nutrients and light. Trees growing in diverse conditions gain their social status in the stand, which, in the end, influences their development and biomass allocation. The objective of this research was to discover if stand density or tree social status has an impact on a tree’s aboveground biomass allocation. The study was carried out in five premature and five mature pine stands, growing in the same soil conditions. The selected sample stands had a different growing density, from low to high. In each sample stand, 10 trees were selected to represent a different social status, according to the Schädelin classification. There were 100 trees felled in total (50 in the premature stands and 50 in the mature stands), for which the dry biomass of the stem, living and dead branches, needles, and cones was determined. The results showed that stand density only had an impact on the branches’ biomass fraction but not the stem and foliage fractions, while social status had an impact on all the fractions. Dominant and codominant trees, as well as those with developed crowns, had a smaller share of the stem and higher share of branches in comparison with trees of a lower social status.
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Schulze, E. D., W. Schulze, H. Koch, A. Arneth, G. Bauer, F. M. Kelliher, D. Y. Hollinger, et al. "Aboveground biomass and nitrogen nutrition in a chronosequence of pristine Dahurian Larix stands in eastern Siberia." Canadian Journal of Forest Research 25, no. 6 (June 1, 1995): 943–60. http://dx.doi.org/10.1139/x95-103.
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Measurements of aboveground biomass and nitrogen (N) nutrition were made during July 1993 in 50-, 130-, and 380-year-old stands of Larixgmelinii (Rupr.) Rupr. in eastern Siberia. Constituting six forest types based on understorey plants, the stands were representative of vegetation throughout the Yakutsk region. Average tree height, diameter, and density ranged from 2 m, 23 mm, and 50 800 stems/ha in the 50-year-old stand to 11 m, 160 mm, and 600 stems/ha in the oldest stand. Aboveground biomass in the 50-year-old stand was 4.4 kg•m−2, and the aboveground N pool was 1.1 mol•m−2. This was slightly higher than the N pool in a 125-year-old stand with a Ledum understorey (1.0 mol•m−2), despite its higher biomass (7.2 kg•m−2). The highest observed aboveground biomass in a 125-year-old stand (characterized by the N2-fixing understorey plant Alnasterfruticosa) reached 12.0 kg•m−2, but the corresponding N pool was only 1.6 mol•m−2. In the oldest stand, aboveground biomass was 8.9 kg•m−2 and the N pool was 1.1 mol•m−2. There was thus a relatively constant quantity of N in the aboveground biomass of stands differing in age by almost 400 years. We postulate that N sets a limit on carbon accumulation in this boreal forest type. Trees were extremely slow growing, and there was essentially no aboveground biomass accumulation between the ages of 130 and 380 years because of a lack of available N. This conclusion was supported by graphical analysis indicating that the self-thinning process in our stands was not governed by the availability of radiation according to allometric theory. Much of the available N was used in the production of tree stems where 86% of the aboveground N (and 96% of aboveground biomass) was immobilized in the oldest stand. N in wood of the old stand exceeded the N pool in the litter layer and was 20% of the N pool in the Ah horizon. The processes of carbon and N partitioning were further explored by the estimation of carbon and N fluxes during three periods of forest development. We calculated a loss of ecosystem N during the period of self-thinning, while in the mature stands the N cycle appeared to be very tight. The immobilized N is returned from the wood into a plant-available form only by a recurrent fire cycle, which regenerates the N cycle. Thus fire is an essential component for the persistence of the L. gmelinii forest.
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Hunt, S. L., A. M. Gordon, and D. M. Morris. "Aspects of ecological development in managed stands of jack pine and black spruce in northern Ontario: Understory vegetation and nutrient relations." Forestry Chronicle 81, no. 1 (February 1, 2005): 61–72. http://dx.doi.org/10.5558/tfc81061-1.
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This study investigated relationships between understory vegetation and nutrient pools in managed stands of jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana [Mill.] BSP) in the Lake Nipigon region of northern Ontario. The species composition, biomass, and nutrient pool sizes in the understory vegetation, as well as biomass and nutrient pools in trees and soils, were determined in 16 managed stands ranging in age from 10 to 53 years since establishment and one mature, natural stand. Patterns of above-ground biomass accumulation in understory vegetation varied with overstory tree species and general site type (dry, sandy soils, or mesic, finer-textured soils). Understory vegetation contributed little (0.3 to 2.6%) to total above-ground organic matter (live biomass plus forest floor) but accounted for higher proportions of total above-ground nutrient pools (e.g., 0.7 to 3.4% of N; 3.2 to 11.7% of K) and net primary productivity (1.2 to 21.2%). The species composition of the understory vegetation was strongly related to stand basal area as well as to concentrations of nutrients (N, P, K, Ca, Mg) in the forest floor and mineral soil. The greatest amount of change in vegetation community composition occurred from the pre-to post-canopy closure stages of stand development; fewer differences were observed among stands of a given species and site type 35 to 50 years after establishment. The effects of silvicultural practices were detected in certain stands 35 years after establishment; for example the most severely treated (bladed and thinned) jack pine stand differed from other stands of similar age and soils with its Cladina/Vaccinium-dominated understory, and large amounts of biomass in the moss/lichen stratum. The understory vegetation communities in other managed jack pine stands, by 35 to 50 years, were similar to that of the mature, natural stand, indicating resilience to silvicultural disturbances. Silviculture may have lasting effects on understory vegetation biomass and species composition through its effects on stand basal area, overstory species, and soil nutrients. This research serves as baseline information for further studies into the ecology of managed stands in northern Ontario. Key words: understory, nutrients, managed forests, jack pine, black spruce, canonical correspondence analysis
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Namm, Brandon H., and John-Pascal Berrill. "How do tree- and stand-level factors influence belowground biomass and carbon storage in tanoak (Notholithocarpus densiflorus)?" Forestry Chronicle 96, no. 01 (May 2020): 50–60. http://dx.doi.org/10.5558/tfc2020-007.
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Tanoak (Notholithocarpus densiflorus) is the most common hardwood in northern California forests, yet its capacity for belowground carbon storage is unknown. To study relationships between coarse roots and tree and stand variables, we destructively sampled twelve tanoak root systems in Humboldt County, California. To estimate belowground biomass, we summed measured biomass of the root ball and a subsample of lateral roots along with predicted biomass of unmeasured coarse roots. Tree size was the best linear predictor of belowground biomass and carbon, indicating that a 25-cm diameter tanoak, for example, stored 70 kg of biomass and 34 kg of carbon in its root system. Stand density was also influential: a doubling of stand density index reduced belowground carbon by 22% for the average tanoak. The mean root-toshoot ratio of 0.35 varied between 0.11 and 0.65, with larger tanoak at high stand densities allocating proportionally less biomass belowground than small open-grown tanoak. The findings highlight the importance of accounting for stand density effects, otherwise belowground carbon will be under predicted in low-density stands managed for tree health, vigor, and resistance to drought and wildfire, or overestimated in forests managed at high densities for high carbon sequestration.
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Aosaar, Jürgen, and Veiko Uri. "Biomass production of grey alder, hybrid alder and silver birch stands on abandoned agricultural land." Forestry Studies / Metsanduslikud Uurimused 48, no. 1 (January 1, 2008): 53–66. http://dx.doi.org/10.2478/v10132-011-0055-0.
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Halli lepa, hübriidlepa ja arukase biomassi produktsioon endistel põllumaadel The present study is based on four experimental sites, located in Southern-Estonia: hybrid alder and grey alder plantations located in Põlva county, and two sample plots of silver birch, located in Tartu county. The stand characteristics, above-ground biomass and current annual production (CAP) were estimated in order to evaluate production capacity of different tree species growing on abandoned agricultural lands. Due to fast growth and high biomass production capacity the most promising tree species for short-rotation forestry in Estonia is grey alder. The stem mass in the 13-years-old grey alder and hybrid alder stand was 63.4 t ha-1 and 40.0 t ha-1, respectively. However, the different biomass production is mainly affected by stand densities, 6170 trees per ha and 4080 trees per ha, respectively. During ageing, the differences between the alder stands diminish. At the age of 14, mean height and diameter at breast height were practically equal. Also the mean stem mass in the older, 13-year old stand, is almost equal: 10.3 kg in grey alder stand and 9.8 kg in hybrid alder stand. At a younger age, the mean stem mass was higher in grey alder stand, but later, at the age of 13, the mean stem mass has become almost the same (10.3 kg in grey alder stand and 9.8 kg in hybrid alder stand). The rotation period for hybrid alder is longer than for grey alder and bulk maturity will occur later. Silver birch is also a highly productive tree species and has a prospect for short-rotation forestry. The mean stem mass and annual current increment of 8-year-old silver birch stand was in same the magnitude as in the grey alder stand. Although the average stand diameter and height were lower in the silver birch stand than in the grey alder stand, it is compensated by the higher wood density of birch wood. The number of trees has affected silver birch stand production, the above-ground biomass in the very high density birch stand (35 600 trees per ha) was significantly lower than in the sparse stand (11 600 trees per ha), 22.8 t ha-1 and 31.2 t ha-1, respectively.
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Šebeň, Vladimír, Bohdan Konôpka, Michal Bošeľa, and Jozef Pajtík. "Contrasting development of declining and living larch-spruce stands after a disturbance event: A case study from the High Tatra Mts." Forestry Journal 61, no. 3 (September 1, 2015): 157–66. http://dx.doi.org/10.1515/forj-2015-0024.
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AbstractThe decline of spruce stands caused by bark beetle outbreaks is a serious economic and ecological problem of forestry in Slovakia. In the preceding period, the decline affected mainly secondary spruce forests. Over the last decade, due to large bark-beetle outbreaks this problem has been observed also in natural spruce forests, even at high elevations. We dealt with this issue in a case study of short-term development of larch-spruce stands in the High Tatras (at a site called Štart). We compared the situation in the stand infested by bark beetles several years after the wind-throw in 2004 with the stand unaffected by bark beetles. We separately analysed the development of the mature (parent) stands and the regeneration. The results indicated that forest decline caused by bark beetles significantly depended on the stand structure (mainly tree species composition), which affected the period of stand disintegration. Mortality of spruce trees slowed down biomass accumulation (and thus carbon sequestration) in the forest ecosystem. In the new stand, pioneer tree species dominated (in the conditions of the High Tatras it is primarily rowan), although their share in the parent stand was negligible. The results showed different trends in the accumulation of below-ground and above-ground biomass in the declined and living stands. In the first years after the stand decline, rowan accumulated significantly more biomass than the main tree species, i.e. spruce. The reverse situation was under the surviving stand, where spruce trees accumulated more biomass than rowan. The different share of spruce and pioneer tree species, mainly rowan, affected the ratio between fixed (in woody parts of trees) and rotating (in foliage) carbon in the undergrowth. Forest die-back is a big source of carbon emissions from dead individuals, and the compensation of these losses in the form of carbon sequestration by future stands is a matter of several decades.
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Claus, A., and E. George. "Effect of stand age on fine-root biomass and biomass distribution in three European forest chronosequences." Canadian Journal of Forest Research 35, no. 7 (July 1, 2005): 1617–25. http://dx.doi.org/10.1139/x05-079.
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Fine-root (<2 mm) biomass and biomass distribution were determined in different age-classes of three European forest chronosequences dominated by Fagus sylvatica L., Picea abies (L.) Karst., and Quercus cerris L., respectively. Root samples were taken with the auger method. There was a clear effect of stand age on standing fine-root biomass, with the highest fine-root biomass in adult but not mature stands. The vertical fine-root biomass distribution showed, at all sites, high densities of roots in the top soil layers and with depth a gradual decrease of fine-root biomass density. The difference in total fine-root biomass between the different age-classes appeared to be due to differences in the top soil layers. Fine-root biomass in the lower soil layers was less variable along the life cycle of the forests. Only in very young stands, specific root length of fine roots was higher than in the other age-classes. The present data together with other published values suggest that fine-root biomass in tree stands develops in three phases: rapid increase after a clear-cut harvest up to a maximum of fine-root biomass; a decrease during maturation of the stand; and a steady-state in mature stands.
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Litton, Creighton, Dennis Knight, and Michael Ryan. "Above-and Belowground Carbon Allocation in Post-Fire Lodgepole Pine Forests: Effects of Tree Density and Stand Age." UW National Parks Service Research Station Annual Reports 25 (January 1, 2001): 123–29. http://dx.doi.org/10.13001/uwnpsrc.2001.3475.
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Validating the different components of the carbon (C) budget in forest ecosystems is essential for developing allocation rules that allow accurate predictions of global C pools and fluxes. In addition, a better understanding of the effects of natural disturbances on C cycling is critical - particularly in light of changes in disturbance regimes that may occur with alterations in global climate. This study investigates the indirect effects of fire on C cycling in lodgepole pine (Pinus contorta var. latifolia Engelm. ex Wats.) stands in Yellowstone National Park by examining above- and belowground C pools, fluxes and allocation patterns in post-fire stands that vary in tree density and stand age (four forest types: low (50,000 trees/ha) in 13-yrÂold stands; and ~110-yr-old mature stands). Above and belowground biomass were estimated to investigate the effect of tree density on biomass partitioning in young stands. The effect of tree density on soil-surface C02 efflux (Fs) and microbial biomass C (Cmic) in young stands was also examined, and data from mature stands were used as a proxy of pre-fire conditions to estimate the extent of ecosystem recovery 13 years after a stand replacing fire. Finally, the effects of tree density and stand age on ecosystem C pools, fluxes and allocation patterns were investigated. Partitioning of biomass to belowground increased with tree density in young stands primarily as a result of inherent differences associated with tree size, not competition. Fs and Cmic increased with tree density in young stands and with stand age, and both Fs and Cmic were correlated exclusively with biotic variables. These findings support recent studies demonstrating the prevailing importance of plants in controlling overall rates of Fs, and suggest that increased decomposition of older, recalcitrant soil C pools is relatively unimportant following fire. Fire, through influences on tree density and stand age, has important and lasting effects on the magnitude of C pools and fluxes in lodgepole pine ecosystems. However, results presented here suggest that overall C allocation patterns following fire are independent of tree density and stand age.
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Mitchell, Dana, and Tom Gallagher. "Chipping Whole Trees for Fuel Chips: A Production Study." Southern Journal of Applied Forestry 31, no. 4 (November 1, 2007): 176–80. http://dx.doi.org/10.1093/sjaf/31.4.176.
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Abstract A time and motion study was conducted to determine the productivity and cost of an in-woods chipping operation when processing whole small-diameter trees for biomass. The study removed biomass from two overstocked stands and compared the cost of this treatment to existing alternatives. The treatment stands consisted of a 30-year-old longleaf pine stand and a 37-year-old loblolly pine stand. In the longleaf pine stand, 71% of the trees removed were less than 5 in. dbh. In the loblolly pine stand, approximately 81% of the stems removed were less than 5 in. dbh. The harvesting system consisted of conventional ground-based harvesting equipment and a three-knife chipper that processed the biomass into fuel chips. The average production time to fill a chip van was 24.61 minutes. The chip moisture content averaged 94.11% (dry basis). Using machine rates and federal labor wage rates, the in-woods cost of producing fuel chips was $9.18/green ton (gt). The cost of the biomass chipping operation ($15.18/gt), including transportation, compared favorably to existing alternative treatments of cut-and-pile or mulching.
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Slim, FJ, PM Gwada, M. Kodjo, and MA Hemminga. "Biomass and litterfall of Ceriops tagal and Rhizophora mucronata in the mangrove forest of Gazi Bay, Kenya." Marine and Freshwater Research 47, no. 8 (1996): 999. http://dx.doi.org/10.1071/mf9960999.
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Biomass and (leaf) litter production of stands of Rhizophora mucronata and Ceriops tagal were assessed in an East African mangrove forest. Inundation frequency of the R. mucronata stand was twice a day (on average 575 min day-1), whereas the C. tagal stand was inundated only during spring tides (on average 116 min day-1). The highest above-ground biomass (24.9 � 4.0 kg dry weight m<.-2) was present in the R. mucronata stand, in which leaf litter production was 2.51 � 1.15 g DW mw2 day-1. Above-ground biomass and leaf litterfall in the C. tagal stand were 4.01 � 0.34 kg DW m-2 and 1.05 � 0.49 g DW m-2 day-1, respectively. There was a distinct seasonal pattern in litterfall in both stands, with lower litterfall values in the wet season. Chloride concentrations were relatively high in senescent leaves, compared with those in green leaves. The decreased litterfall during the wet periods may be related to a reduced accumulation of chloride in the leaves. The difference in inundation frequency between the R. mucronata and C. tagal stands is expected to cause a more substantial tidal export of fallen leaves from the R. mucronata stand. As nitrogen resorption before defoliation was similar for C. tagal (50.9%) and R. mucronata (50.1%), tidal flushing may cause larger nitrogen losses from the R. mucronata stand.
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Crotteau, Justin S., Annelise Z. Rue-Johns, and Jeffrey C. Barnard. "Effects on understory biomass and forage 8–10 years after precommercial thinning of Sitka spruce – western hemlock stands in southeast Alaska." Canadian Journal of Forest Research 50, no. 2 (February 2020): 215–25. http://dx.doi.org/10.1139/cjfr-2019-0268.
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In southeast Alaska, United States, multiple-use forest management objectives include both timber production and wildlife habitat. Following stand-replacing disturbances such as clear-cutting, Sitka spruce (Picea sitchensis (Bong.) Carrière) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) naturally regenerate and competitively dominate resources, excluding understory biomass and biodiversity. Thinning may mitigate the effects of canopy closure and permit understory development, but evidence of the effect on understories 8–10 years after thinning is lacking. We report results 4–5 and 8–10 years after thinning experiments on the Tongass National Forest to demonstrate the effects of precommercial thinning (thinned versus control), stand age (15–25, 25–35, and 35–50 years), and weather on understory dynamics and Sitka black-tailed deer (Odocoileus hemionus sitkensis Merriam, 1898) forage availability. Stand density negatively affected understory biomass, whereas temperature and precipitation positively interacted to increase biomass. Thinning had an enduring effect on understories, with biomass at least twice as great in thinned versus unthinned stands through year 10. We identified compositional differences from thinning as stand age class increased. Deer forage responded similarly to biomass, but thinning-induced differences faded with increased winter snowfall scenarios, especially in older stands. This study aids the understanding of stand overstory and understory development following silvicultural treatments in the coastal temperate rain forest of Alaska and suggests management implications and applications for balancing objectives throughout the forest type.
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Bohdan, Konôpka, Pajtík Jozef, and Marušák Róbert. "Canopy closure altered biomass allocation in young spruce stand." Journal of Forest Science 61, No. 2 (June 3, 2016): 62–71. http://dx.doi.org/10.17221/101/2014-jfs.
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Augusto, L., N. Crampon, E. Saur, M. R. Bakker, S. Pellerin, C. de Lavaissière, and P. Trichet. "High rates of nitrogen fixation of Ulex species in the understory of maritime pine stands and the potential effect of phosphorus fertilization." Canadian Journal of Forest Research 35, no. 5 (May 1, 2005): 1183–92. http://dx.doi.org/10.1139/x05-054.
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Nitrogen (N2) fixation by Ulex species was studied in a range of mature maritime pine (Pinus pinaster Ait.) stands as well as in a phosphorus (P) fertilization trial in a young (6-year-old) open pine stand. The biomass was estimated by allometric relationships, and the percentage of N derived from atmosphere was calculated according to the natural 15N abundance method. Ulex stand biomass was lower in the mature pine stand than in the young open pine stand. In the latter pine stand, Ulex mean annual biomass increment ranged from 1 to 5 Mg·ha1·year1, increasing with P fertilization dose, as did the Ulex stand biomass, ranging from 5.4 to 31.1 Mg·ha1 after six growing seasons in the most highly fertilized treatment. For the sites where the natural 15N abundance method was applicable, the calculated percentage of N in the Ulex europaeus L. tissues derived from atmosphere was very high (mean = 82%; range = 59%100%). At the other sites, the N2 fixation was probably also very important but could not be calculated with confidence. Here, the mean fixation rate of the former sites was used to calculate the N2 fixation flux. The estimated annual N2 fixation flux ranged from 0.5 to 5.1 kg N·ha1·year1 in the mature pine stands. In the young open pine stand, the Ulex understory fixation ranged from 8.1 to 57.4 kg N·ha1·year1, increasing with P fertilization dose. Considering the low levels of N fluxes in theses ecosystems, these figures are very high.
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Wang, Weiqian, Ya Wang, Xiaoxia Li, Yan Liu, and Qiaoqiao Huang. "Individual growth, competitive ability and stand-level biomass production of invasive Sorghum halepense populations on Hainan island, China." Journal of Plant Ecology 14, no. 5 (March 26, 2021): 793–804. http://dx.doi.org/10.1093/jpe/rtab032.
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Abstract Aims Sorghum halepense is a perennial invasive weed causing great harm worldwide, including some regions on Hainan island. In this study, we compared the performance between plants from outbreaking (dense stands covering large areas) and those from non-outbreaking (less dense stands covering smaller areas) populations. We also tested the hypothesis that plants with greater intraspecific competitive ability will have a lower stand biomass when grown under high-density conditions. Methods We grew plants of S. halepense individually, with an intraspecific competitor, with two interspecific competitors and with three or six plants from the same population per pot, and tested whether outbreaking and non-outbreaking populations differed in their performance. We also tested whether stand biomass (i.e. total biomass when three or six plants were grown together) was related to total biomass of individuals grown alone, and intra- or interspecific competitive ability. Important Findings Outbreaking and non-outbreaking populations of S. halepense differed in their biomass when individuals were grown alone, but not when grown in competition or when three or six plants from the same population were grown together. Across populations, biomass of individuals grown alone was negatively correlated with intra- and interspecific competitive ability, indicating that there is a trade-off between individual growth and competitive ability. Stand-level biomass was not related to total biomass of individuals grown alone, and intra- or interspecific competitive ability, indicating that low biomass when grown alone and high competitive ability may not reduce the performance of S. halepense when grown in dense monocultural stands.
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Litton, Creighton M., Michael G. Ryan, Daniel B. Tinker, and Dennis H. Knight. "Belowground and aboveground biomass in young postfire lodgepole pine forests of contrasting tree density." Canadian Journal of Forest Research 33, no. 2 (February 1, 2003): 351–63. http://dx.doi.org/10.1139/x02-181.
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As much as 40% of live biomass in coniferous forests is located belowground, yet the effect of tree density on biomass allocation is poorly understood. We developed allometric equations using traditional harvesting techniques to estimate coarse root biomass for [Formula: see text]13-year-old postfire lodgepole pine trees (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.). We then used these equations, plus estimates of fine root and aboveground biomass, to estimate total tree biomass and belowground to aboveground biomass ratios in young postfire lodgepole pine stands with a wide range of tree densities. Belowground biomass allocation increased with tree density, but the increase was largely determined by inherent differences associated with tree size, not competition. Stand biomass in trees ranged from 46 to 5529 kg·ha1 belowground, from 176 to 9400 kg·ha1 aboveground, and from 222 to 13 685 kg·ha1 for total biomass. For individual trees, the ratio of belowground to total biomass declined with tree size from 0.44 at a basal diameter of 0.5 cm to 0.11 at a basal diameter of 8 cm. This shift in individual tree allocation caused the proportion of total stand biomass in belowground tissues to increase from 19% in low-density stands with larger trees to 31% in high-density stands with small trees.
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Domke, Grant M., Andrew J. David, Anthony W. D'Amato, Alan R. Ek, and Gary W. Wycoff. "Hybrid Aspen Response to Shearing in Minnesota: Implications for Biomass Production." Northern Journal of Applied Forestry 28, no. 3 (September 1, 2011): 117–22. http://dx.doi.org/10.1093/njaf/28.3.117.
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Abstract There is great potential for the production of woody biomass feedstocks from hybrid aspen stands; however, little is known about the response of these systems to silvicultural treatments, such as shearing. We sought to address this need by integrating results from more than 20 years of individual tree and yield measurements in hybrid aspen (Populus tremuloides Mich. × P. tremula L.) stands in north central Minnesota. Specifically, tree and stand-level responses are described in terms of sucker density, early diameter and height characteristics, volume, and biomass production. Overall, shearing treatments increased the density of hybrid aspen stems, relative to preshear densities at the same age. In addition, average stem diameter and volume as well as stand-level biomass were considerably greater in hybrid aspen stands relative to similarly aged native aspen stands also established via shearing treatment. These findings illustrate that coppice systems using hybrid aspen provide great potential to rapidly produce biomass feedstocks, with little management investment.
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Sytnyk, Svitlana, Viktoriia Lovynska, and Ivan Lakyda. "Foliage biomass qualitative indices of selected forest forming tree species in Ukrainian Steppe." Folia Oecologica 44, no. 1 (June 27, 2017): 38–45. http://dx.doi.org/10.1515/foecol-2017-0005.
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AbstractOur study objective was research on the assimilation component of aboveground biomass of trees and its correlation with mensurational indices of trees (age, diameter and height) in stands of the main forest forming species in the Ukrainian Northern Steppe zone - Pinus sylvestris L. (Scots pine) and Robinia pseudoacacia L. (Black locust). The research was carried out in forest stands subordinated to the State Agency of Forest Resources of Ukraine. We used experimental data collected on sample plots established during years 2014-2016. The main research results prove that the foliage share in the tree greenery biomass structure had a wide range of values. For both investigated species, a positive correlation was found between the dry matter content in the tree foliage and the tree age, height and diameter. The foliage share in tree greenery biomass decreased with increasing mensurational index values. Correlation analysis revealed linear relationships between the mensurational indices and the discussed aboveground live biomass parameters. The closest correlation was observed between the stand age, mean stand diameter, mean stand height and dry matter content in the foliage.
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Turner, Kathryn G., Claire M. Lorts, Asnake T. Haile, and Jesse R. Lasky. "Effects of genomic and functional diversity on stand-level productivity and performance of non-native Arabidopsis." Proceedings of the Royal Society B: Biological Sciences 287, no. 1937 (October 21, 2020): 20202041. http://dx.doi.org/10.1098/rspb.2020.2041.
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Biodiversity can affect the properties of groups of organisms, such as ecosystem function and the persistence of colonizing populations. Genomic data offer a newly available window to diversity, complementary to other measures like taxonomic or phenotypic diversity. We tested whether native genetic diversity in field experimental stands of Arabidopsis thaliana affected their aboveground biomass and fecundity in their colonized range. We constructed some stands of genotypes that we a priori predicted would differ in performance or show overyielding. We found no relationship between genetic diversity and stand total biomass. However, increasing stand genetic diversity increased fecundity in high-resource conditions. Polyculture (multiple genotype) stands consistently yielded less biomass than expected based on the yields of component genotypes in monoculture. This under-yielding was strongest in stands with late-flowering and high biomass genotypes, potentially due to interference competition by these genotypes. Using a new implementation of association mapping, we identified genetic loci whose diversity was associated with stand-level yield, revealing a major flowering time locus associated with under-yielding of polycultures. Our field experiment supports community ecology studies that find a range of diversity-function relationships. Nevertheless, our results suggest diversity in colonizing propagule pools can enhance population fitness. Furthermore, interference competition among genotypes differing in flowering time might limit the advantages of polyculture.
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DesRochers, Annie, and Victor J. Lieffers. "Root biomass of regenerating aspen (Populus tremuloides) stands of different densities in Alberta." Canadian Journal of Forest Research 31, no. 6 (June 1, 2001): 1012–18. http://dx.doi.org/10.1139/x01-037.
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In north-central Alberta, 12 plots (9 m2) were hydraulically excavated in young trembling aspen (Populus tremuloides Michx.) stands (510 years old) of different sucker density to quantify the effects of sucker density on the parental root system, on the formation of new roots and on the growth of suckers. All roots were collected and divided into live and dead parental roots and new root categories. Size and age of parent roots at the time of suckering were determined. Total biomass ranged from 1 to 18 t/ha of live roots. Living root biomass was proportional to stand density and leaf area index (LAI). Low-density stands had a higher proportion of dead roots. Suckers in plots with more parental root biomass/sucker had greater height growth. Root/shoot ratios ranged from 0.46 to 3.52 but were not correlated with stand densities. Stands with larger basal area of suckers and greater mean parent root diameter produced more biomass of new roots. This research suggests that young sucker-origin aspen stands support a large underground biomass and that high sucker densities and LAI are required to prevent loss of parental root biomass.
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Uthbah, Zinatul, Eming Sudiana, and Edy Yani. "ANALISIS BIOMASA DAN CADANGAN KARBON PADA BERBAGAI UMUR TEGAKAN DAMAR (Agathis dammara (Lamb.) Rich.) DI KPH BANYUMAS TIMUR." Scripta Biologica 4, no. 2 (June 1, 2017): 119. http://dx.doi.org/10.20884/1.sb.2017.4.2.404.
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Increased carbon dioxide in the atmosphere causes global climate change seriously. Forests serve as an important asset that can absorb and store carbon in the form of biomass. One type of potential forest as a carbon sink is forests resin. The amount of carbon stored by standing very dynamic and varies according to the age of its standing. Therefore, studies will be needed to determine the effect of age on biomass and carbon stocks stands resin, determine the relationship between age and standing biomass and carbon stocks resin, and knowing the optimum resin stand age in storing biomass and carbon stocks. This research was conducted at the stands of resin RPH Karang Gandul, KPH Banyumas Timur for four weeks in May 2016. The method used is a survey with a sampling technique using cluster random sampling. Stands resin used in the study were classified into five age groups with 5 replicates. Data were analyzed using ANOVA with an error rate of 5% and continued with LSD for further test results were significant and regression analysis to determine the relationship of age with biomass and carbon stocks stands resin. The results showed that the age effect on biomass and carbon stocks stands resin, the relationship formed between the age of stand with biomass and carbon stocks are quadratic, and age optimum in storing biomass and carbon stocks is 35 years.
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Puhlick, Joshua J., Aaron R. Weiskittel, Shawn Fraver, Matthew B. Russell, and Laura S. Kenefic. "Assessing the role of natural disturbance and forest management on dead wood dynamics in mixed-species stands of central Maine, USA." Canadian Journal of Forest Research 46, no. 9 (September 2016): 1092–102. http://dx.doi.org/10.1139/cjfr-2016-0177.
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Dead wood pools are strongly influenced by natural disturbance events, stand development processes, and forest management activities. However, the relative importance of these influences can vary over time. In this study, we evaluate the role of these factors on dead wood biomass pools across several forest management alternatives after 60 years of treatment on the Penobscot Experimental Forest in central Maine, USA. After accounting for variation in site quality, we found significant differences in observed downed coarse woody material (CWM; ≥7.6 cm small-end diameter) and standing dead wood biomass among selection, shelterwood, and commercial clear-cut treatments. Overall, total dead wood biomass was positively correlated with live tree biomass and was negatively correlated with the average wood density of nonharvest mortality. We also developed an index of cumulative harvest severity, which can be used to evaluate forest attributes when multiple harvests have occurred within the same stand over time. Findings of this study highlight the dynamic roles of forest management, stand development, and site quality in influencing dead wood biomass pools at the stand level and underscore the potential for various outcomes from the same forest management treatment applied at different times in contrasting stands.
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Gautam, Tilak Prasad, and Tej Narayan Mandal. "Effect of disturbance on fine root biomass in the Tropical moist forest of eastern Nepal." Nepalese Journal of Biosciences 2 (January 24, 2013): 10–16. http://dx.doi.org/10.3126/njbs.v2i0.7484.
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Fine root biomass (<5 mm diameter) was estimated in 0-15 cm and 15- 30 cm soil depths of disturbed and undisturbed stands of tropical moist forest in eastern Nepal. The value of root mass was higher (4.28 t ha-1) in the undisturbed stand than the disturbed stand (2.04 t ha-1). The biomass of smaller fine roots (<2 mm diameter) was 1.51 and 3.2 t ha-1 in the disturbed and undisturbed stands respectively. Most of the fine roots were present in the surface soil layer (0-15 cm), in both the disturbed and undisturbed stands (67% in the disturbed and 64% in the undisturbed). The nitrogen stock in the fine roots was more (38.61 kg ha-1) in undisturbed stand than the disturbed stand (16.93 kg ha-1). More nitrogen was confined in the fine roots of <2 mm diameter in both undisturbed (28.8 kg ha-1) and disturbed (13.59 kg ha-1) stands. DOI: http://dx.doi.org/10.3126/njbs.v2i0.7484 Nepalese Journal of Biosciences 2 : 10-16 (2012)
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Zhang, Xiao, Xueli Zhang, Hui Han, Zhongjie Shi, and Xiaohui Yang. "Biomass Accumulation and Carbon Sequestration in an Age-Sequence of Mongolian Pine Plantations in Horqin Sandy Land, China." Forests 10, no. 2 (February 22, 2019): 197. http://dx.doi.org/10.3390/f10020197.
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The Mongolian pine (Pinus sylvestris L. var. mongolica Litv.) was first introduced to the southeastern Horqin sandy land in the mid-1950s. Since then, it has been widely planted and has become the most important conifer species in Northern China, providing significant ecological, economic and social benefits. However, its function in sequestering carbon at different developmental stages has been little studied. In this study, twenty plots inventory and destructive sampling of eight trees were conducted in 12-, 19-, 34-, 48- and 58-year-old Mongolian pine stands of China. Allometric biomass equations (ABEs) for tree components were established and used to determine the magnitude and distribution of tree biomass and carbon density. The carbon density of the understory, forest floor and soil was also determined. The ABEs with age as the second variable could simply and accurately determine the biomass of plantation tree branches, foliage and fruit, which were considerably influenced by age. With increasing stand age, the proportion of stem biomass to total tree biomass increased from 22.2% in the 12-year-old stand to 54.2% in the 58-year-old stand, and the proportion of understory biomass to total ecosystem biomass decreased, with values of 7.5%, 4.6%, 4.4%, 4.1% and 3.0% in the five stands. The biomass of the forest floor was 0.00, 1.12, 2.04, 6.69 and 3.65 Mg ha−1 in the five stands. The ecosystem carbon density was 40.2, 73.4, 92.9, 89.9 and 87.3 Mg ha−1 in the 12-, 19-, 34-, 48-, and 58-year-old stands, in which soil carbon density accounted for the largest proportion, with values of 67.4%, 76.8%, 73.2%, 63.4%, and 57.7% respectively. The Mongolian pine had the potential for carbon sequestration during its development, especially in the early stages, however, in the later growth stage, the ecosystem carbon density decreased slightly.
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Sabatia, Charles O., Rodney E. Will, and Thomas B. Lynch. "Effect of Thinning on Aboveground Biomass Accumulation and Distribution in Naturally Regenerated Shortleaf Pine." Southern Journal of Applied Forestry 33, no. 4 (November 1, 2009): 188–92. http://dx.doi.org/10.1093/sjaf/33.4.188.
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Abstract The accumulation and relative distribution of standing biomass to different aboveground tree components was investigated in 46–53-year-old naturally regenerated shortleaf pine (Pinus echinata Mill.) stands growing in the Ouachita Mountains of southeastern Oklahoma that were thinned to different levels 16 years previously. The thinning levels were 50% full stocking, 70% full stocking, and a 140% full stocking unthinned control. After 16 years, the unthinned controls had more total aboveground biomass, bole wood, bark, and foliage standing biomass per hectare but had less branch standing biomass than the more heavily thinned stands. Foliage biomass as a proportion of total stand biomass was similar among the three treatment levels. Bark biomass proportion was significantly less in thinned to 50% treatment compared with the other treatments. Bole wood biomass proportion in thinned to 50% treatment was significantly less than in the control. The proportion in branches was significantly greater in the thinned treatments compared with the proportion in the unthinned control. These results suggest that thinning increases biomass distribution to branches at the expense of stems, after 16 years of postthinning stand growth.
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Lo Monaco, Angela, and Paolo Cantiani. "Forest Stand Management and Biomass Growth." Forests 12, no. 9 (September 15, 2021): 1253. http://dx.doi.org/10.3390/f12091253.
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He, Shao Juan, Yong Chang Ye, Jian Yun Zhu, and Lu Zhang. "Carbon Accounting and Evaluation for Natural and Planted Forest Stands in South China." Advanced Materials Research 610-613 (December 2012): 3328–31. http://dx.doi.org/10.4028/www.scientific.net/amr.610-613.3328.
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Three forest stands, i.e., natural secondary broadleaved mixed stand, 3-year-old eucalypt stand and 1-year-old eucalypt stand, were selected for study in Dongguan, south China, for forest carbon accounting and evaluation. The results showed that forest tree carbon stocks for the three stands were 85.6745 t, 17.5570 t, and 6.5469 t for broadleaved mixed stand, 3-year-old eucalypt stand, and 1-year-old eucalypt stand, respectively, while the forest soil carbon stocks for the three forest stands in a descending order were: 3-year-old eucalypt stand (97.0984 t), 1-year-old eucalypt forest stand (96.7272 t), and broadleaved mixed forest (84.6288 t), respectively. Using a carbon tax criterion, we evaluate the monetary benefit of carbon stock for each forest stand, with the broadleaved forest stand having the highest total value. This study suggested that the perennial broadleaved forest stand has significant advantage over 1-year or 3-year-old eucalypt stands in biomass carbon stocks, however, eucalypt stands have great potentials in soil carbon stock due to more organic material return from litter.
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Fons, Jaume, and Karel Klinka. "Temporal variations of forest floor properties in the Coastal Western Hemlock zone of southern British Columbia." Canadian Journal of Forest Research 28, no. 4 (April 1, 1998): 582–90. http://dx.doi.org/10.1139/x98-027.
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We examined temporal changes in the forest floor across a zonal chronosequence represented by four stages of stand development: stand initiation ( <= 7 years after disturbance), stem exclusion ( ±40-year-old stands), understory reinitiation ( ±60-year-old stands), and old-growth (>350-year-old) stands. All stages, except the old-growth, had a similar history of disturbance: clear-cutting without subsequent burning and silvicultural treatments. Considering thickness and chemical and biotic properties of the LF and H horizons, the most dissimilar stages were the stand initiation and old-growth, and the most similar stages were the stem exclusion and understory reinitiation. Compared with the old-growth stage, the stand initiation stage had about the same thickness of LF and H horizons and bacterial biomass but lower acidity, C:N ratio, fungal biomass, and soil fauna density and higher N mineralization. The stem exclusion and understory reinitiation stages had, in general, properties intermediate between the stand initiation and old-growth stage, with a gradual increase in acidity, C:N ratio, and fungal and faunal populations. After clear-cutting, the forest floor showed inevitable qualitative and quantitative alterations in response to the open-area climate. At the same time, it showed resilience, as most faunal groups of the old-growth stage were present in the stand initiation stage.
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Magnussen, Steen, Paul Boudewyn, and Rene Alfaro. "Spatial prediction of the onset of spruce budworm defoliation." Forestry Chronicle 80, no. 4 (August 1, 2004): 485–94. http://dx.doi.org/10.5558/tfc80485-4.
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A logistic regression model for spatially explicit predictions of the likelihood of an onset of stand-level spruce budworm (Choristoneura fumiferana, Clemens) defoliation in a 15 000 km2 study area in northern British Columbia, Canada is developed. Predictions are derived from stand (volume and needle biomass) and topographic attributes (distance from nearest river, distance from previous year defoliation, and stand elevation) collected during the first 12 years of a current budworm outbreak. The likelihood of an onset of defoliation increased with an increase in stand volume and biomass of current needles and it decreased with an increase in the distance to the nearest river and to the nearest stand with a defoliation recorded for the year prior to the year of prediction. Stands located at higher elevations sustained less defoliation than stands located at lower elevations. A single model is assumed adequate for predictions throughout an entire outbreak cycle. Observed and predicted relative frequencies of locations with an onset of defoliation compared relatively well. Key words: Choristoneura fumiferana; Picea; logistic regression; nearest neighbour distance
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Omdal, Daniel W., William R. Jacobi, and Charles G. Shaw. "Estimating Large-Root Biomass from Breast-Height Diameters for Ponderosa Pine in Northern New Mexico." Western Journal of Applied Forestry 16, no. 1 (January 1, 2001): 18–21. http://dx.doi.org/10.1093/wjaf/16.1.18.
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Abstract An important component of forest ecosystems in the southern Rocky Mountains is the belowground biomass associated with mature stands of ponderosa pine (Pinus ponderosa). Information on root biomass is fundamental to understanding the dynamics of ecological systems and designing studies of those systems. Ponderosa pine trees from a stand in northern New Mexico were cut and their root systems excavated. Biomass of all roots > 0.6 cm in diameter and the belowground portion of the stump was determined on a dry-weight basis. A regression model was constructed using data on breast-height diameter and belowground stump and coarse-root biomass from 42 trees in the stand. Diameter at breast height ranged from 18.3 to 67.6 cm, and belowground biomass ranged from 3 to 576 kg. West. J. Appl. For. 16(1):18–21.
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Osawa, A., A. P. Abaimov, and T. Kajimoto. "Feasibility of estimating total stem volume and aboveground biomass from measurement on the largest trees in even-aged pure stands." Canadian Journal of Forest Research 31, no. 11 (November 1, 2001): 2042–48. http://dx.doi.org/10.1139/x01-137.
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Feasibility was tested of estimating the total stem volume and aboveground biomass from data of only the largest trees in even-aged pure stands. We applied a method of fitting a size-distribution function to data that exclude information of smaller individuals in a stand and compared the predicted stem volume and aboveground biomass with those calculated with data of all living trees in the stand. The paired t test showed that the predicted values of the total stem volume and aboveground biomass were not different (p = 0.05) from those observed even if only the largest 10% of the trees were used for estimation with the 3/2 power distribution. Results were similar with the beta-type distribution; however, data from at least the largest 30% of the trees in the stand must be included. Absolute values of the relative error of the predicted total stem volume or aboveground biomass were generally in the range 1020%, indicating that the present method is accurate enough to be used for calculation of these variables. However, there is systematic bias in the predictions of the total stem volume and aboveground biomass of a stand. Possible causes of the indicated biases and potential ways for improvement of the predictions were discussed.
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Dong, Zhang, and Li. "Evaluation of Stand Biomass Estimation Methods for Major Forest Types in the Eastern Da Xing’an Mountains, Northeast China." Forests 10, no. 9 (August 21, 2019): 715. http://dx.doi.org/10.3390/f10090715.
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Currently, forest biomass estimation methods at the regional scale have attracted the greatest attention from researchers, and the development of stand biomass models has become popular a trend. In this study, a total of 5074 measurements on 1053 permanent sample plots were obtained in the Eastern Da Xing’an Mountains, and three additive systems of stand biomass equations were developed. The first additive system (M-1) used stand variables as the predictors (i.e., stand basal area and average height), the second additive system (M-2) utilized stand volume as the sole predictor, and the third additive system (M-3) included both stand volume and biomass expansion and conversion factors (BCEFs) as the predictors. The coefficients of the three model systems were estimated with nonlinear seemingly unrelated regression (NSUR), while the heteroscedasticity of the model residuals was solved with the weight function. The jackknifing technique was used on the residuals, and several statistics were used to assess the prediction performance of each model. We comprehensively evaluated four stand biomass estimation methods (i.e., M-1, M-2, M-3 and a constant BCEF (M-4)). Here, we showed that the (1) three additive systems of stand biomass equations showed good model fitting and prediction performance, (2) M-3 significantly improved the model fitting and performance and provided the most accurate predictions for most stand biomass components, and (3) the ranking of the four stand biomass estimation methods followed the order of M-3 > M-2 > M-4 > M-1. Our results demonstrated these additive stand biomass models could be used to estimate the stand aboveground and belowground biomass for the major forest types in the Eastern Da Xing’an Mountains, although the most appropriate method depends on the available data and forest type.
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Farooq, Taimoor, Wenjing Wu, Mulualem Tigabu, Xiangqing Ma, Zongming He, Muhammad Rashid, Matoor Gilani, and Pengfei Wu. "Growth, Biomass Production and Root Development of Chinese fir in Relation to Initial Planting Density." Forests 10, no. 3 (March 7, 2019): 236. http://dx.doi.org/10.3390/f10030236.
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Chinese fir (Cunninghamia lanceolata (Lamb) Hook) is a commercially valuable timber species that is widely planted in southern China and accounts for 6.1% of the global plantation forests. However, appropriate planting density that ensures high plantation productivity is largely unexplored in this species. The aim of the study was to examine tree growth, biomass production, and its allocation among different organs in relation to initial planting density, and to examine whether planting density has an impact on root development. Mortality, diameter at breast height and tree-height of all trees were determined and measured in wider (2.36 × 2.36 m), intermediate (1.83 × 1.83 m) and narrow (1.44 × 1.44 m) spacing with stand density of 1450 trees ha−1, 2460 trees ha−1 and 3950 trees ha−1, respectively. In each stand, three plots of 20 × 20 m at a distance of 500 m were delineated as the sampling unit. Biomass was determined by destructive sampling of trees in each stand and developing allometric equations. Root morphological traits and their spatial distribution were also determined by carefully excavating the root systems. The results showed an increase in diameter of trees with decreasing stand density while tree height was independent of stand density. Biomass production of individual trees was significantly (p < 0.05) less in high-density stand (32.35 ± 2.98 kg tree−1) compared to low-density stand (44.72 ± 4.96 kg tree−1) and intermediate-density stand (61.35 ± 4.78 kg tree−1) while stand biomass production differed significantly in the order of intermediate (67.63 ± 5.14 t ha−1) > high (57.08 ± 3.13 t ha−1) > low (27.39 ± 3.42 t ha−1) stand density. Both average root length and root volume were significantly (p < 0.05) lower in the high-density stand than stands with low and intermediate density. Analysis of spatial distribution of root systems revealed no overlap between roots of neighboring trees in the competition zone in low-density stand, a subtle overlap in the intermediate density stand and larger overlap in the high-density stand. It can be concluded that better growth and biomass production in intermediate density stand could be explained by better root structural development coupled with minimal competition with understory vegetation and between trees; thus intermediate stand density can be optimal for sustaining long-term productivity and may reduce the management cost in the early phase of the plantation.
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Węgiel, Andrzej, Ernest Bielinis, and Krzysztof Polowy. "Macronutrient Stocks in Scots Pine Stands of Different Densities." Forests 9, no. 10 (September 22, 2018): 593. http://dx.doi.org/10.3390/f9100593.
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A positive nutrient balance is crucial to sustaining forest productivity. Differences in stand densities usually mean different aboveground biomass stocks and different proportions of tree compartments. These differences can be reflected in the different macronutrient stocks between stands of different densities, because various tree compartments have different element concentrations. In this study, 82-year-old stands of Scots pine were compared, and specifically, the concentrations of the elements in tree compartments and the amounts of macronutrients in aboveground biomass were compared. The nutrients considered in this study were nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur. A positive correlation between stand density and the level of stored macronutrients was found for nitrogen, phosphorus, and potassium. This result means that forest managers can influence nutrient balances by regulating stand densities or by harvesting methods (SOH: stem-only harvesting or WTH: whole-tree harvesting).
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Andrade, Thiago Cavalcante Gomes Ribeiro de, Nairam Félix de Barros, Luiz Eduardo Dias, and Maria Inês Ramos Azevedo. "Biomass yield and calorific value of six clonal stands of Eucalyptus urophylla S. T. Blake cultivated in Northeastern Brazil." CERNE 19, no. 3 (September 2013): 467–72. http://dx.doi.org/10.1590/s0104-77602013000300014.
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The worldwide demand for clean, sustainable energy has increased in recent years. A potential alternative energy source is biomass from nonnative forests, particularly from the genus Eucalyptus spp. in the specific case of Brazil, currently with several selected clonal stands for energy production. Because each stand adapts differently to different environments, specific studies are required in order to evaluate energy production in a given region. The objective of this study is to determine, from among six clonal stands of Eucalyptus urophylla S. T. Blake, which have greater potential for production of biomass and energy in the South Central region of Maranhão (Grajaú). Clonal stands planted at a spacing of 4 x 3 m apart were evaluated at age 41 months, distributed in a completely randomized design with five replicates. Each experimental plot consisted of 100 trees. Analysis included determining biomass yield and distribution in each tree portion as well as calorific value of bark and wood components. Out of the six clonal stands, two outdid the others both in biomass yield and in energy generation, surpassing the least yielding stand by up to 27%.
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McMullin, Richard Troy, Ian D. Thompson, Brian W. Lacey, and Steven G. Newmaster. "Estimating the biomass of woodland caribou forage lichens." Canadian Journal of Forest Research 41, no. 10 (October 2011): 1961–69. http://dx.doi.org/10.1139/x11-108.
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Lichens are an important winter food source for woodland caribou ( Rangifer tarandus caribou ), but quantifying their abundance is difficult. Here, we present an efficient method for assessing lichen biomass at the stand level in boreal forests. We measured lichens occurring in high enough abundance to serve as a winter food source for woodland caribou in 51 boreal forest stands. Samples of each species or genus were collected from each stand and a mean abundance (cover) to biomass ratio was established. The method does not require samples to be collected or weighed, due to this predetermined relationship, and it also accounts for the variation in biomass among lichen species that are equally abundant. The variation in lichen growth between stands was assessed by means of five lichen abundance classes. The proposed method was tested in 34 stands with a wide range of ages and stem densities. The average time to complete a lichen biomass assessment was approximately 2 h. This method is an efficient and accurate tool that can assist forest managers and researchers with ecological studies on lichens or with monitoring changes in lichen biomass over time and with habitat assessments for organisms for which lichens are important, such as woodland caribou.
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Ali, Ashfaq, Adnan Ahmad, Kashif Akhtar, Mingjun Teng, Weisheng Zeng, Zhaogui Yan, and Zhixiang Zhou. "Patterns of Biomass, Carbon, and Soil Properties in Masson pine (Pinus massoniana Lamb) Plantations with Different Stand Ages and Management Practices." Forests 10, no. 8 (July 30, 2019): 645. http://dx.doi.org/10.3390/f10080645.
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Masson pine (Pinus massoniana Lamb) has been planted extensively in different parts of China for timber production and habitat restoration. The effects of stand age and management of these plantations on biomass, carbon storage, and soil physicochemical properties are poorly understood. In this study, we investigated biomass, carbon storage, and soil physicochemical properties of Masson pine plantations. The plantations were divided into four age groups (9, 18, 28, and 48 years), and into managed (MS) and unmanaged stands (UMS) in Hubei province, Central China. Tree biomass increased with stand age. A growth model indicated that maximum tree growth occurred when the plantations were 17 years old, and the average growth rate occurred when plantations were 23 years old. Tree biomass in managed stands was 9.75% greater than that in unmanaged ones. Total biomass carbon was estimated at 27.4, 86.0, 112.7, and 142.2 Mg ha−1, whereas soil organic carbon was 116.4, 135.0, 147.4, and 138.1 Mg ha−1 in 9-, 18-, 28-, and 48-year-old plantations, respectively. Total carbon content was 122.6 and 106.5 Mg ha−1, whereas soil organic carbon content was 104.9 and 115.4 Mg ha−1 in MS and UMS, respectively. Total carbon storage in the plantations studied averaged 143.7, 220.4, 260.1, and 280.3 Mg ha−1 in 9-,18-, 28-, and 48-year-old stands, and 227.3 and 222.4 Mg ha−1 in MS and UMS, respectively. The results of our study provide a sound basis for estimating ecosystem carbon as it relates to forest management activity and stand age.