Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: Residual tree stands.
Статті в журналах з теми "Residual tree stands"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 статей у журналах для дослідження на тему "Residual tree stands".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте статті в журналах для різних дисциплін та оформлюйте правильно вашу бібліографію.
1
Roy, Vincent, Robert Jobidon, and Louis Blais. "Étude des facteurs associés au dépérissement du bouleau à papier en peuplement résiduel après coupe." Forestry Chronicle 77, no. 3 (2001): 509–17. http://dx.doi.org/10.5558/tfc77509-3.
Повний текст джерелаАнотація:
Following harvesting operations within the Quebec mixedwood region, decadence symptoms are frequently observed on residual paper birch trees, compromising future harvests. Simultaneously, these residual stands are often a constraint to the establishment and growth of valuable regeneration. In the context of intensive forest management and preservation of the conifer component in mixedwood stands, it is important to identify factors associated with paper birch post-logging decadence. Ninety-eight (98) stands were sampled along a partial cutting chronosequence of 1 to 11 years old in order to examine five site variables and six stand variables susceptible of explaining post-logging decadence. Classification and regression tree (CART) models indicated that stand variables, mainly residual basal area and time since harvest, were the best predictor variables of decadence. This study suggests maintaining a basal area of at least 16 m2/ha and preserving larger diameter stems when the objective is to maintain healthy paper birch for further harvesting. When the silvicultural objective is to regenerate softwoods, this study recommends keeping a residual basal area after partial cutting of no more than 4 m2/ha. Keywords: residual trees, competition, mixed stands, partial cutting, tree regression, regeneration
2
Seablom, Thomas J., and David D. Reed. "Assessment of Factors Contributing to Residual Tree Damage from Mechanized Harvesting in Northern Hardwoods." Northern Journal of Applied Forestry 22, no. 2 (2005): 124–31. http://dx.doi.org/10.1093/njaf/22.2.124.
Повний текст джерелаАнотація:
Abstract Seven northern hardwood stands were evaluated for damage after mechanized harvesting. Four different harvesting systems were evaluated: harvester and grapple skidder, processor and forwarder, chainsaw and cable skidder, and chainsaw and forwarder. There was not an excessive amount of damage occurring to any of the residual stands, and there was an adequate number of residual trees per acre in all diameter classes to meet residual stand structure goals. The majority of the damage that did occur was to the bole portion of the tree and to the 2–8-in. dbh size classes. There was no strong relationship between amount of damage occurring to residual trees and the number of residual trees per acre, residual basal area per acre, or distance to skid trail. These results indicate that mechanized harvesting can be used in northern hardwoods without causing excessive damage to the residual stand. Recommendations are to continue with current silvicultural prescriptions and to increase forester-operator communication to minimize residual tree damage.North. J. Appl. For. 22(2):124–131.
3
Smyth, Cheryl, Jim Schieck, Stan Boutin, and Shawn Wasel. "Influence of stand size on pattern of live trees in mixedwood landscapes following wildfire." Forestry Chronicle 81, no. 1 (2005): 125–32. http://dx.doi.org/10.5558/tfc81125-1.
Повний текст джерелаАнотація:
Burned areas and patches of residual live trees were mapped from post-fire aerial photographs of 168 mixedwood stands (a total of 9367 ha), in eight large wildfires in the boreal forest of northern Alberta. The stands were stratified into three size classes: small (<10 ha), medium (10–60 ha), and large (>60 ha).We described the area occupied by single live residual trees, unburned patches of live trees and partially burned patches of live trees within these mixedwood stands. Although results from individual stands were highly variable, there was proportionally more area covered by live residual trees in large fire-killed stands compared to medium stands, which in turn had proportionally more than small stands. For most sizes and types of live tree patches, larger fire-killed stands had a greater proportion of live tree area compared to smaller stands. Results of this study are compared to similar studies and current harvest guidelines. We outline the amount and distribution of live tree patches that would be needed to create harvest areas similar to that found after wildfire. Key words: natural disturbance, wildfire, live residual trees, ecosystem management, forest harvest pattern, boreal mixedwood
4
Sokol, Kerry A., Michael S. Greenwood, and William H. Livingston. "Impacts of Long-Term Diameter-Limit Harvesting on Residual Stands of Red Spruce in Maine." Northern Journal of Applied Forestry 21, no. 2 (2004): 69–73. http://dx.doi.org/10.1093/njaf/21.2.69.
Повний текст джерелаАнотація:
Abstract Diameter-limit harvesting has long been suspected as a dysgenic forestry practice, but a conclusive, practical demonstration of the effects of this selection technique on residual tree performance is lacking. To determine the effects of repeated diameter-limit harvesting on the phenotypes of residual trees, we compared radial growth patterns of residual red spruce trees (with ages greater than 100 years) after diameter-limit harvests with those of residual trees in stands subjected to positive selection harvesting. After nearly 50 years of repeated harvesting, residual trees in the diameter-limit stands were nearly 40% smaller and had grown 32% slower than residual trees in positive selection stands. Furthermore, diameter-limit residuals were initially smaller and remained significantly smaller than positive selection residuals throughout their lifespan, despite major release events. After release, the diameter-limit trees responded with increased growth rates, but the increase was relatively small. Growth rates were consistently and significantly lower for diameter-limit residuals until the final 20 yr when growth rates in each treatment converged. Our results indicate that red spruce stands subjected to repeated diameter-limit harvesting will develop progressively less valuable growing stock with limited growth potential.
5
Perry, Roger W., and Ronald E. Thill. "Initial Effects of Reproduction Cutting Treatments on Residual Hard Mast Production in the Ouachita Mountains." Southern Journal of Applied Forestry 27, no. 4 (2003): 253–58. http://dx.doi.org/10.1093/sjaf/27.4.253.
Повний текст джерелаАнотація:
Abstract We compared indices of total hard mast production (oak and hickory combined) in 20, second-growth, pine-hardwood stands under five treatments to determine the effects of different reproduction treatments on mast production in the Ouachita Mountains. We evaluated mast production in mature unharvested controls and stands under four reproduction cutting methods (single-tree selection, group selection, shelterwood, and clearcut with wildlife tree retention) during the first 6 yr after initial harvest. Mean Whitehead mast production indices were greater in shelterwoods and clearcuts with wildlife tree retention than in unharvested stands 5 of the 6 yr of study, indicating individual trees in these stands produced greater amounts of hard mast. Stand production values for the 6 yr combined indicated group selections generally produced the greatest amounts of total hard mast, probably because competing pines in the matrix were thinned and hard mast-producing tree densities were unchanged after harvest. However, wide variation in residual density of mast trees existed among stands of the same treatment. Our results indicate hard mast production can be affected by different silvicultural treatments and managers should consider the importance of residual mast production along with other objectives when determining silvicultural treatments to apply. South. J. Appl. For. 27(4):253–258.
6
Miller, Gary W., and H. Clay Smith. "A Practical Alternative to Single-Tree Selection?" Northern Journal of Applied Forestry 10, no. 1 (1993): 32–38. http://dx.doi.org/10.1093/njaf/10.1.32.
Повний текст джерелаАнотація:
Abstract When landowners want to develop and maintain an uneven-aged tree structure in eastern hardwood stands, single-tree selection often is suggested as the only advisable, long-term partial regeneration harvest method. Single-tree selection is preferred because it provides a means for improving quality and controlling stocking of the residual stand necessary for sustained yield of desired products. Although studies have shown that single-tree selection is feasible where desirable shade-tolerant species can be regenerated, it is rarely applied because marking stands for harvest can be difficult and time consuming. Instead, diameter-limit cutting is the most common partial regeneration practice used in eastern hardwoods, primarily because it is much easier to apply. Unfortunately, strict diameter-limit cuts do not provide for control of residual stocking or improve the quality of residual trees. However, based on 20-yr results, most objectives of single-tree selection can be attained with flexible diameter-limit harvest guidelines based on potential value increase of individual trees combined with an improvement cut in small sawtimber trees at each periodic cut. North. J. Appl. For. 10(1):32-38.
7
Heitzman, Eric, and Adrian G. Grell. "Residual Tree Damage Along Forwarder Trails from Cut-to-Length Thinning in Maine Spruce Stands." Northern Journal of Applied Forestry 19, no. 4 (2002): 161–67. http://dx.doi.org/10.1093/njaf/19.4.161.
Повний текст джерелаАнотація:
Abstract In Maine and adjacent eastern Canadian provinces, cut-to-length harvesting has emerged as an ecologically attractive method of thinning conifer plantations and natural stands. Yet regional information on the extent of residual stand damage associated with this system is lacking. Eight naturally regenerated red spruce (Picea rubens) stands in northern Maine were studied; all stands were thinned in 1997–1998 with a processor and forwarder combination. Field methods consisted of examining individual trees near forwarder trails for bole damage and measuring the size and aboveground height of individual wounds. The frequency of trees damaged in each stand ranged from 25–46%. The four sites with the highest pre- and post-cut tree densities generally had the greatest number of damaged trees. Trees located along forwarder trails were more frequently damaged than nontrailside trees. The average individual wound size ranged from 2.6–8.7 in.2; 82–98% of the wounds in each stand were less than or equal to 10 in.2 in size. Usually, wounds on trailside trees were not significantly larger than wounds on nontrailside trees. Regardless of tree location, most wounds were located 3–6 ft above ground level.
8
Walter, Scott T., and Chris C. Maguire. "Conifer response to three silvicultural treatments in the Oregon Coast Range foothills." Canadian Journal of Forest Research 34, no. 9 (2004): 1967–78. http://dx.doi.org/10.1139/x04-068.
Повний текст джерелаАнотація:
This study assessed growth, condition, and mortality of residual trees one decade after harvest across three silvicultural treatments in thirty 85- to 125-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in the Oregon Coast Range foothills. Group-selection cuts had 33% of the entire stand volume extracted as patches approximately 0.20.8 ha in size; two-story regeneration harvests had 75% of the volume extracted, and 2030 residual trees/ha were left; clearcuts had all trees removed, except for 1.2 trees/ha. One decade after harvest, tree basal area, diameter, and height growth, and crown width and fullness did not differ between silvicultural treatments. In contrast, live crown ratio was largest in clearcuts (0.74), and the proportion of trees with epicormic branching was highest in two-story stands (35%). Overall, 45% of trees had more basal area growth in the decade after harvest than in the previous decade. Residual green trees in clearcuts and group-selection stands experienced the highest and lowest percentage mortality, respectively (30.6% vs. 0.2%). Our results reflect little differentiation in the characteristics of trees growing under three silvicultural conditions one decade after harvest. However, percent residual green tree mortality increased with increasing harvest intensity.
9
Howard, Andrew F. "Damage to residual trees from cable yarding when partial cutting second-growth stands in coastal British Columbia." Canadian Journal of Forest Research 26, no. 8 (1996): 1392–96. http://dx.doi.org/10.1139/x26-155.
Повний текст джерелаАнотація:
Damage to residual trees associated with a specific combination of stand conditions, silvicultural treatment, and harvesting system must be known if this information is to guide foresters in the design of prescriptions for individual stands planned for partial cutting. A study was made of residual tree damage in two stands of second growth in coastal British Columbia that were partially cut and the timber was yarded with cable systems. Damage to residual trees was found to be high at both sites. The percentage of trees damaged decreased with increasing distance from the skyline corridor, and bigger trees were less likely to be damaged than small ones. Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) was shown to be the least susceptible to damage, followed by western hemlock (Tsugaheterophylla (Raf.) Sarg.) and finally western redcedar (Thujaplicata Donn ex D. Don). Wider spacing of skyline corridors is suggested as one means for reducing stand damage.
10
Acker, S. A., E. K. Zenner, and W. H. Emmingham. "Structure and yield of two-aged stands on the Willamette National Forest, Oregon: implications for green tree retention." Canadian Journal of Forest Research 28, no. 5 (1998): 749–58. http://dx.doi.org/10.1139/x98-039.
Повний текст джерелаАнотація:
Green tree retention, a practice based on ecosystem science, has been integrated into forest management as a working hypothesis, requiring research and monitoring to quantify its effects. We undertook a retrospective study of natural, two-aged forest stands on the Willamette National Forest to provide preliminary estimates of the effects of green tree retention on forest structure and yield. Fourteen stands in the western hemlock (Tsuga heterophylla (Raf.) Sarg.) zone (mostly dominated by Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco) were sampled using adjacent, paired plots: one with residual trees over a younger cohort (median age of younger cohort, 97 years) and one with only the younger cohort. The younger cohorts all had much higher densities of trees than typical of local Douglas-fir plantations. Basal area, volume, and mean annual increment (MAI) of the younger cohort all declined with increasing residual tree basal area. These relationships were best described by curvilinear models; the greatest effect per unit of residual tree basal area occurred at low residual tree levels (5-10 m2/ha). For 10 m2/ha residual tree basal area (equivalent to about 12 average (diameter at breast height 105 cm) residual trees per hectare), we predicted a 26% decline in younger cohort MAI (95% confidence interval: -30% to -22%).
11
Rice, James A., G. Blake MacDonald, and David H. Weingartner. "Precommercial thinning of trembling aspen in northern Ontario: Part 1 – Growth responses." Forestry Chronicle 77, no. 5 (2001): 893–901. http://dx.doi.org/10.5558/tfc77893-5.
Повний текст джерелаАнотація:
In Ontario, trembling aspen (Populus tremuloides Michx.) utilization has increased over the past 20 years and this trend is expected to continue. With this increased demand, questions are being raised about stand conditions required for optimum growth. In 1979, a study was initiated across the commercial range of aspen in northern Ontario to determine the optimum precommercial thinning intensities for aspen tree and stand growth. Six pure aspen stands between the ages of five and 22 years were thinned to residual spacings of 2 × 2 m, 3 × 3 m, 4 × 4 m, and 5 × 5 m. Unthinned and thinned plots were measured at regular intervals for up to 17 years after treatment. Diameter increased significantly with residual tree spacing over the range of site conditions, geographic locations, and tree ages. Precommercial thinning resulted in significantly increased height in three of the stands, and height generally increased with increased residual spacing. Fifteen to 17 years after treatment, gross total volume (GTV) was highest in the unthinned plots for all six stands and decreased as residual tree spacing increased. Gross merchantable volume (GMV) did not vary significantly with thinning in all but the oldest stand. The results of this study do not support the use of precommercial thinning to increase aspen fibre yield. However, if the management goal is maximizing individual tree growth, precommercial thinning of aspen should be considered. Key words: Trembling aspen, precommercial thinning, DBH response, height response, northern Ontario
12
Amman, Gene D., Mark D. McGregor, Richard F. Schmitz, and Robert D. Oakes. "Susceptibility of lodgepole pine to infestation by mountain pine beetles following partial cutting of stands." Canadian Journal of Forest Research 18, no. 6 (1988): 688–95. http://dx.doi.org/10.1139/x88-105.
Повний текст джерелаАнотація:
Thinning stands of lodgepole pine (Pinuscontorta Douglas var. latifolia Engelmann) is thought to increase vigor and thereby reduce susceptibility to mountain pine beetle (Dendroctonusponderosae Hopkins). Partial cut stands of lodgepole in the Kootenai and Lolo National forests, Montana, U.S.A., provided opportunity (i) to determine growth response of 76- to 102-year-old lodgepole pines following thinning and (ii) to test the hypothesis that vigor of residual trees infested and uninfested by beetles does not differ. Lodgepole pine stands receiving different partial cutting prescriptions were sampled. Characteristics measured for trees within the sample were diameter at breast height, grams of stem wood per square metre of foliage, periodic growth ratio, and leaf area. Trees in most treatments showed decreased growth the 1st year following thinning. The 1st year was followed by increased growth during the next 4 years. Of the tree characteristics measured, only dbh was significantly different on both forests between live trees and trees killed by the mountain pine beetle; the latter were larger (P < 0.001). The low amount of mountain pine beetle infestation in all stands in the presence of poor growth response and vigor of residual trees suggests that factors other than tree vigor will regulate mountain pine beetle infestations in recently thinned lodgepole pine stands. We hypothesize change in stand microclimate is the principal factor.
13
Wittwer, Robert F., Michael G. Shelton, and James M. Guldin. "Effects of Reproduction Cutting Method and Hardwood Retention on Shortleaf Pine Seed Production in Natural Stands of the Ouachita Mountains." Southern Journal of Applied Forestry 27, no. 3 (2003): 206–11. http://dx.doi.org/10.1093/sjaf/27.3.206.
Повний текст джерелаАнотація:
Abstract Shortleaf pine (Pinus echinata Mill.) seed production was monitored for 4 yr in stands harvested by a range of even- and uneven-aged reproduction cutting methods. The fifty-two 35–40 ac stands were distributed throughout the Ouachita Mountains from central Arkansas to eastern Oklahoma. Seed crops were characterized as good, poor, poor, and bumper, averaging 109,000, 18,000, 5,000, and 379,000 sound seeds/ac, respectively. Seed production the first year after harvest was generally correlated with residual density of shortleaf pines; unharvested control stands, single-tree selection, and shelterwood stands produced more seeds than seed tree stands. Differences in seed production among regeneration cutting methods were not significant for the crop dispersed 4 yr after harvest; this is attributed to release and response of residual seed-producing trees in the seed tree and shelterwood stands. Results also indicated that seed production was lowest for stands located in the western section of the Ouachita Mountains. South. J. Appl. For. 27(3):206–211.
14
Negrón, José F. "Within-Stand Distribution of Tree Mortality Caused by Mountain Pine Beetle, Dendroctonus ponderosae Hopkins." Insects 11, no. 2 (2020): 112. http://dx.doi.org/10.3390/insects11020112.
Повний текст джерелаАнотація:
The mountain pine beetle (MPB) (Dendroctonus ponderosae) is a bark beetle that attacks and kills ponderosa pine (Pinus ponderosa), among other pine species throughout the western conifer forests of the United States and Canada, particularly in dense stands comprising large trees. There is information on the stand conditions that the insect prefers. However, there is a paucity of information on how small-scale variation in stand conditions influences the distribution of tree mortality within a stand. I examined the small-scale distribution of ponderosa pine basal area pre- and post a mountain pine beetle infestation, and used geostatistical modeling to relate the spatial distribution of the host to subsequent MPB-caused tree mortality. Results indicated increased mortality in the denser parts of the stand. Previous land management has changed historically open low-elevation ponderosa pine stands with aggregated tree distribution into dense stands that are susceptible to mountain pine beetles and intense fires. Current restoration efforts are aimed at reducing tree density and leaving clumps of trees, which are more similar to historical conditions. The residual clumps, however, may be susceptible to mountain pine beetle populations. Land managers will want to be cognizant of how mountain pine beetles will respond to restoration treatments, so as to prevent and mitigate tree mortality that could negate restoration efforts.
15
MacDonell, Marc R., and Arthur Groot. "Harvesting peatland black spruce: Impacts on advance growth and site disturbance." Forestry Chronicle 73, no. 2 (1997): 249–55. http://dx.doi.org/10.5558/tfc73249-2.
Повний текст джерелаАнотація:
A project was established in the Lake Abitibi Model Forest to study the effects of several harvesting systems on advance growth protection and site disturbance. Tree-length and cut-to-length harvesting systems were compared to a full-tree system on peatland black spruce (Picea mariana (Mill.) B.S.P.) sites. The impacts of the various harvesting systems were compared by summarizing the structural and mensurational properties of the stands before and after harvest, by evaluating damage to residual trees, and by assessing site disturbance. The tree-length and full-tree systems, which were compared in winter harvesting, produced similar results. The cut-to-length system was compared to the full-tree system in both winter and summer harvesting, and protected substantially more advance growth, especially in the summer. Additionally, the cut-to-length system produced less damage to residual trees and lesser amounts of site disturbance. All harvesting systems resulted in or maintained residual stands with an uneven-size structure. Key words: black spruce, advanced regweneration, tree harvesting, systems
16
Fajvan, Mary Ann, Karl E. Knipling, and Brian D. Tift. "Damage to Appalachian Hardwoods from Diameter-Limit Harvesting and Shelterwood Establishment Cutting." Northern Journal of Applied Forestry 19, no. 2 (2002): 80–87. http://dx.doi.org/10.1093/njaf/19.2.80.
Повний текст джерелаАнотація:
Abstract Residual stand damage was assessed in 10 ac stands harvested with either a 12 in. diameter-limit harvest, a 16 in. diameter-limit harvest or an establishment cut of the shelterwood method. Each stand was logged using manual felling and cable skidding; treatments were replicated four times. The 12 in. diameter-limit harvests had the lowest residual basal areas but residual stems had the highest percentage of damage and largest stem wounds. In all three treatments, as tree size (dbh) increased and distance to skid trail increased, the probability of individual tree damage decreased.
17
Gronewold, Chris, Anthony W. D’Amato, and Brian J. Palik. "Relationships between growth, quality, and stocking within managed old-growth northern hardwoods." Canadian Journal of Forest Research 42, no. 6 (2012): 1115–25. http://dx.doi.org/10.1139/x2012-070.
Повний текст джерелаАнотація:
An understanding of long-term growth dynamics is central to the development of sustainable uneven-aged silvicultural systems for northern hardwood forests in eastern North America. Of particular importance are quantitative assessments of the relationships between stocking control and long-term growth and quality development. This study examined these relationships in a long-term silviculture experiment established in northern hardwood stands in the Upper Peninsula of Michigan, USA. Stands were old growth at the onset of the experiment and were maintained at three residual stocking levels (11.5, 16.1, and 20.7 m2·ha–1) over a 57-year period. Several aspects of long-term stocking control were evaluated, including the effects of residual stocking on tree quality development and the relationships between stand stocking and individual tree growth and stand-level production. Results suggest that residual stocking had little impact on quality development, likely due to the initial old-growth condition of the stands examined. In contrast, our results indicate that a range of stand densities will maintain acceptable rates of stand-level production in selection systems and that growth can be shifted between diameter classes depending on desired future stand conditions.
18
Bradford, John B., Anthony W. D’Amato, Brian J. Palik, and Shawn Fraver. "A new method for evaluating forest thinning: growth dominance in managed Pinus resinosa stands." Canadian Journal of Forest Research 40, no. 5 (2010): 843–49. http://dx.doi.org/10.1139/x10-039.
Повний текст джерелаАнотація:
Growth dominance is a relatively new, simple, quantitative metric of within-stand individual tree growth patterns, and is defined as positive when larger trees in the stand display proportionally greater growth than smaller trees, and negative when smaller trees display proportionally greater growth than larger trees. We examined long-term silvicultural experiments in red pine ( Pinus resinosa Ait.) to characterize how stand age, thinning treatments (thinned from above, below, or both), and stocking levels (residual basal area) influence stand-level growth dominance through time. In stands thinned from below or from both above and below, growth dominance was not significantly different from zero at any age or stocking level. Growth dominance in stands thinned from above trended from negative at low stocking levels to positive at high stocking levels and was positive in young stands. Growth dominance in unthinned stands was positive and increased with age. These results suggest that growth dominance provides a useful tool for assessing the efficacy of thinning treatments designed to reduce competition between trees and promote high levels of productivity across a population, particularly among crop trees.
19
Berrill, John-Pascal, and Kevin L. O’Hara. "Estimating site productivity in irregular stand structures by indexing the basal area or volume increment of the dominant species." Canadian Journal of Forest Research 44, no. 1 (2014): 92–100. http://dx.doi.org/10.1139/cjfr-2013-0230.
Повний текст джерелаАнотація:
Estimating site productivity in irregular structures is complicated by variations in stand density, structure, composition in mixed stands, and suppression experienced by subordinate trees. Our objective was to develop an alternate to site index (SI) and demonstrate its application in models of individual-tree and stand growth. We analyzed coast redwood (Sequoia sempervirens (Lamb. ex D. Don) Endl.) tree and stand growth in a grid of 234 permanent sample plots covering a 110 ha study area in north coastal California. Partial harvesting created a mosaic of densities and openings throughout the 60-year-old redwood-dominated forest. Redwood SI was a poor predictor of volume increment (VI) per hectare among redwood in each plot over two decades after harvest. A new index of redwood basal area increment (BAI) productivity, calculated using inventory data for all stems in even-aged stands and the oldest cohort of multiaged stands, was a stronger predictor of VI. Diameter increment of individual redwood trees correlated strongly with stand density and the new BAI index. Forest managers should expect widely divergent responses following partial harvesting in crowded even-aged stands, with the greatest response coming from dominant redwoods with long crowns retained in areas with low residual stand density and high BAI index.
20
Ward, Jeffrey S., George R. Stephens, and Francis J. Ferrandino. "Influence of Cutting Method on Stand Growth in Sawtimber Oak Stands." Northern Journal of Applied Forestry 22, no. 1 (2005): 59–67. http://dx.doi.org/10.1093/njaf/22.1.59.
Повний текст джерелаАнотація:
Abstract Many upland oak forests in the eastern United States are approaching economic and biological maturity. A study was established in 1981–1984 in three central Connecticut forests to examine the effects of six distinct cutting methods (shelterwood, diameter limit, multiaged crop tree, high grading, silvicultural clearcut, forest preserve) on stand growth and dynamics in sawtimber oak stands. Board-foot volumes (International 1/4) averaged 8.4 mbf/ac before the initial harvest. Sixty-nine percent of sawtimber trees had butt-log grades of 2 or better. Volume growth was significantly lower on high grading plots (36 bf/ac/year) than on the forest preserve, diameter limit, shelterwood, and multiaged crop tree plots (∼214 bf/ac/year) through two cutting cycles. Total board-foot yield (final volumes plus harvested volumes) for the silvicultural clearcut plots (7.3 mbf/ac) was significantly lower than for uncut, shelterwood, and diameter limit cuts, 12.3, 12.5, and 13.0 mbf/ac, respectively. This study showed that three distinct cutting methods: shelterwood, multiaged crop tree, and forest preserve resulted in similar stand volume growth rates in sawtimber oak stands. The first two methods can be used by landowners who wish to generate income to offset expenses. The choice will depend on the aesthetic and regeneration goals of the landowner. Diameter-limit cutting also had similar volume rates, but it was necessary to lower the diameter limits for the second cutting cycle to maintain economically viable harvests. As a consequence, residual stand structure after the second cutting cycle was similar to that for the high grading plots. Although high grading had the highest harvested volume during the first cutting cycle, low quality of residual trees and depressed stand growth rates indicate it is not a viable option for long-term forest management. North. J. Appl. For. 22(1):59–67.
21
Burton, Julia I., Eric K. Zenner, and Lee E. Frelich. "Frost Crack Incidence in Northern Hardwood Forests of the Southern Boreal–North Temperate Transition Zone." Northern Journal of Applied Forestry 25, no. 3 (2008): 133–38. http://dx.doi.org/10.1093/njaf/25.3.133.
Повний текст джерелаАнотація:
Abstract Frost cracks are common in northern hardwood stands near their northern range limits. Although they have long been attributed to the regional climate, temperature fluctuations result in surface cracks largely when internal wounds are present. We examined the relationship between the proportion of trees with frost cracks and both tree-level diameter class and stand structural characteristics in primary stands with a history of minimal logging (n = 4) and 67- to 97-year-old second-growth stands subjected to past heavy partial cuts and high grading (n = 8). We hypothesized that frost crack incidence would (1) be greater in the second-growth stands and (2) be associated with differences in structural attributes between the two stand types. High levels of frost cracking in primary stands indicated that cracks are not completely avoidable. However, the proportion of trees with frost cracks was significantly higher in second-growth than primary stands, particularly on small-diameter trees. For example, the odds for frost cracking were 1.66–3.74 times greater in second-growth than in primary stands in the 15-cm diameter class, but were not different in the 45+-cm diameter class. Frost cracking was positively associated with increasing diameter in both stand types. Structural characteristics reflecting tree size, stand basal area, and basal area of hardwoods were positively associated with the proportion of trees with frost cracks in second-growth stands but not in primary stands. Although the basal area of conifers was negatively associated with frost cracking, the effect was likely due to a reduction in hardwood basal area in the vicinity of conifers. We suggest that greater frost crack incidence in second-growth stands is likely a consequence of injuries to residual trees during selective logging.
22
Ostrofsky, W. D., R. S. Seymour, and R. C. Lemin Jr. "Damage to northern hardwoods from thinning using whole-tree harvesting technology." Canadian Journal of Forest Research 16, no. 6 (1986): 1238–44. http://dx.doi.org/10.1139/x86-219.
Повний текст джерелаАнотація:
A mechanized whole-tree harvesting system, which has recently found widespread use in northern New England, was evaluated for its impact on residual crop trees in two northern hardwood stands in western Maine. Stand type, skid trail spacing, and whether or not skid trails were designated prior to harvesting significantly influenced stand damage levels. A higher mean percentage of residual trees was injured in a Betulapapyrifera Marsh, stand (49%) than in similar treatments in a Fagusgrandifolia Ehrh. – Quercusrubra L. stand (32%). A spacing of 20 m between predesignated trails resulted in less damage (22%) to the remaining trees than a spacing of 40 m (53%), but with many more potential crop trees cut for trails. At both sites, highest total damage was found in treatments where no skid trails were predesignated, with 82 and 43% of the crop trees damaged or removed in the B. papyrifera stand and the Fagus–Quercus stand, respectively. Models were developed to predict the effects of thinning systems, tree size, species, dbh, stand basal area, and distance from tree to skid trail on the probability of being damaged. High damage levels indicate that such harvesting systems are unsuitable for some sites and require careful planning and layout on all sites.
23
Vincent, Manon, Cornelia Krause, and Ahmed Koubaa. "Influence of Stem Taper on the Yield of Black Spruce Stands and Trees Following Commercial Thinning." Forests 10, no. 11 (2019): 1024. http://dx.doi.org/10.3390/f10111024.
Повний текст джерелаАнотація:
In this work, we examine the effects of commercial thinning on stand volume and individual stem form in nine naturally regenerated black spruce (Picea mariana (Mill.) B.S.P.) stands. We compared these study sites with controls in the commercial boreal forest of northern Quebec, Canada. At stand level, dendrochronological data provided insight into changes in stand volume ten years after thinning. Analysis of a subsample of six individual trees from each commercially thinned stand and three individual trees from the controls illustrated the role of thinning on stem shape development. Although average volume increased for residual stems in thinned stands slightly more than in the controls (110% versus 106%), the treatment effect stand-level volume increment or stand-level total volume harvested (ten years after treatment) was not statistically significant. Moreover, at tree level, thinning did not significantly affect stem volume increment. However, radial growth increment significantly increased after treatment. Trees from commercially thinned stands showed a significantly higher growth increment along the lower first two-thirds of the stem. Response to thinning at tree level correlated strongly with the size and number of harvested competitors around a residual stem. We conclude that commercial thinning modified wood allocation rather than wood volume and did not affect taper and stem shape. These patterns of post-cutting growth are explained by wood allocation following thinning. After commercial thinning, growth increment is favored at the expense of height growth. As the treatment effect was found at the stem scale rather than at the stand scale, further research is needed in regard to commercial thinning treatments to investigate how to increase productivity at the stand scale.
24
O'Hara, K. L. "Stand structure and growing space efficiency following thinning in an even-aged Douglas-fir stand." Canadian Journal of Forest Research 18, no. 7 (1988): 859–66. http://dx.doi.org/10.1139/x88-132.
Повний текст джерелаАнотація:
The growth of individual trees from four thinning treatments in a 64-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stand was analyzed to determine desirable residual stand structures after thinning. Dominant and codominant trees had the highest individual tree stem volume growth rates over the previous 5 years, and accounted for most stand volume growth in thinned and unthinned stands. Two measures of growing space, crown projection area and sapwood basal area (a surrogate for leaf area), were used to measure how efficiently individual trees used their growing space. Crown classes were useful in characterizing growing space efficiency (volume growth per unit of growing space) only in the unthinned treatment. In thinned treatments, tall trees with medium-sized crowns were most efficient, while in the unthinned treatment, tall trees with relatively large crowns were most efficient. A large crown in an unthinned stand was comparable in size to a medium-sized crown in a thinned stand. Results suggest growing space is not limiting individual tree growth in thinned stands and that thinning to a particular stand structure is more appropriate than thinning to a particular level of stand density.
25
Lejeune, P. "Développement d'un modèle de type arbre appliqué à la croissance des peuplements feuillus irréguliers du sud de la Belgique." Canadian Journal of Forest Research 26, no. 10 (1996): 1838–48. http://dx.doi.org/10.1139/x26-209.
Повний текст джерелаАнотація:
A model predicting circumference growth of individual trees has been developed for mixed irregular stands dominated by Fagussilvatica L. in southeastern Belgium. This model integrates simultaneously tree, stand, and growing site characteristics without considering distances between individual trees. It has a determination coefficient of 40.1% and a residual standard deviation of 0.45 cm/year. Forest mensuration variables considered in the model are circumference, tree social position represented by the total basal area of trees greater than the subject tree, stand basal area, and some index of stand structure corresponding to the ratio of the variance over the mean circumference. The site component is essentially expressed by the length of the growing period. The low accuracy obtained for individual tree growth is relative because the results are used mainly after individual trees have been distributed into size classes. We have been able to show that the introduction of crown description in the model can increase its accuracy. But this modification requires a submodel describing crown changes over time.
26
Vandygriff, J. C., E. M. Hansen, B. J. Bentz, K. K. Allen, G. D. Amman, and L. A. Rasmussen. "Long-term efficacy of diameter-limit cutting to reduce mountain pine beetle-caused tree mortality in a lodgepole pine forest." Forestry Chronicle 91, no. 04 (2015): 444–56. http://dx.doi.org/10.5558/tfc2015-074.
Повний текст джерелаАнотація:
Mountain pine beetle, Dendroctonus ponderosae Hopkins, is the most significant mortality agent in pine forests of western North America. Silvicultural treatments that reduce the number of susceptible host trees, alter age and size class distributions, and diversify species composition are considered viable, long-term options for reducing stand susceptibility to mountain pine beetle-caused tree mortality. Short-term efficacy of thinning treatments has been evaluated, but long-term efficacy has not. We evaluated mountain pine beetle-caused lodgepole pine mortality in 2008, ∼28 years after diameterlimit cutting from above that removed the largest diameter lodgepole pines in a Wyoming, USA forest. Following extensive recent mountain pine beetle activity, the partially-cut stands had significantly less mountain pine beetle-caused tree mortality compared to untreated reference stands. These results are similar to observations five years post-treatment, albeit using different reference stands because the original controls were lost to timber harvest. The original management objective was reduced mountain pine beetle-caused tree mortality, and this objective was achieved, lasting for up to 28 years. Despite the reduced mortality among partially-cut stands, however, untreated and treated stands had similar densities of residual live mature lodgepole pine and those in untreated stands had larger average diameters.
27
Mainwaring, Douglas B., Douglas A. Maguire, Alan Kanaskie, and Jeff Brandt. "Growth responses to commercial thinning in Douglas-fir stands with varying severity of Swiss needle cast in Oregon, USA." Canadian Journal of Forest Research 35, no. 10 (2005): 2394–402. http://dx.doi.org/10.1139/x05-164.
Повний текст джерелаАнотація:
Concern has risen about the degree to which Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands with severe infections of Swiss needle cast (SNC) respond to thinning. A retrospective study was established in the fall of 2001 to assess the growth of Douglas-fir stands that were commercially thinned between 4 and 10 years ago. Current SNC infection levels in these stands ranged from severe to very light. Past volume and basal area growth declined with increasing severity of SNC, as measured by current foliage retention and crown length / sapwood ratio. As has been observed in many other studies, thinning to lower residual stock reduced stand level growth; however, individual tree growth increased with lower residual stand density. The ratio of growth in successive periods and analysis of annual basal area growth since thinning suggested that trees did respond to thinning, although less so as SNC increased. A positive response to thinning, regardless of infection level, was confirmed by an analysis of annual trends in basal area growth over the first 5 years after thinning.
28
Valkonen, S. "Effect of retained Scots pine trees on regeneration, growth, form, and yield of forest stands." Forest Systems 9 (January 1, 2000): 121–45. http://dx.doi.org/10.5424/680.
Повний текст джерелаАнотація:
Green tree retention is predominantly motivated by the increasing complexity of objectives in forest management. It is one of the major methods for the creation of structurally complex stands for ecological and amenity benefits. Retention may promote regeneration in terms of regular seed tree, shelterwood, planting, or direct seeding methods. The effect of retaining Scots pine trees to various degrees and in varying stand structures was assessed, with emphasis on regeneration results, development of the juvenile stand, tree quality and economic results were assessed. Group retention seems to be the simplest way to practise retention with Scots pine for ecological and amenity purposes. Considerable difficulties can be expected when trying to regenerate pine under a dense shelter, naturally or artificially. After the regeneration phase, residual trees have adverse effects on the young generation. Sustainable uneven-aged structures are hard to create and maintain with Scots pine.
29
Ward, Jeffrey S., and Jessica Wikle. "Increased Individual Tree Growth Maintains Stand Volume Growth after B-Level Thinning and Crop-Tree Management in Mature Oak Stands." Forest Science 65, no. 6 (2019): 784–95. http://dx.doi.org/10.1093/forsci/fxz042.
Повний текст джерелаАнотація:
AbstractSix study areas were established in 80–125-year-old upland oak stands on average sites to compare stand and individual tree growth response following two active treatments (B-level thinning, crop tree) with an unmanaged control. Initial stocking of 104 percent was reduced to 62 percent and 60 percent on the B-level and crop-tree-management plots, respectively. Approximately 7,200 board feet per acre (International ¼) were harvested on the actively managed plots with upland oaks accounting for 81 percent of pre- and 86 percent of residual stand. Eleven-year diameter and volume growth of oak sawtimber trees was greater on actively managed plots. Growth response increased with degree of release and was maintained for the length of the study. Because of the increased individual tree growth of oaks in response to release, stand volume growth of oak sawtimber did not differ between treatments. In contrast to an 11-year decline of poletimber stocking on unmanaged plots, poletimber stocking increased on managed plots as diameter growth increased in response to partial release. This may increase difficulty of regenerating oak in the future. For those mature red oak stands where traditional regeneration prescriptions will not be implemented or will be delayed, commercial harvests can be conducted without compromising stand volume growth of oak.
30
Leak, William B. "Thinning Northern Hardwoods in New England by Dominant-Tree Removal—Early Results." Northern Journal of Applied Forestry 24, no. 4 (2007): 312–13. http://dx.doi.org/10.1093/njaf/24.4.312.
Повний текст джерелаАнотація:
Abstract Commercial thinning is a widely accepted practice in northern hardwood stands of New England. Commercial thinning guidelines for eastern hardwoods generally recommend releasing selected crop trees or the removal of trees in less-than-dominant crown classes unless they are of poor health or quality. However, many northern hardwood stands in New England have a dominant crown class with a high proportion of paper birch and aspen. These species mature at an early age (50–70 years) and usually are marketable in stands of that age. In this study, most of the paper birch and aspen (the largest trees) in a 69-year-old northern hardwood stand were removed in a thinning operation, leaving a medium- to well-stocked stand of longer-lived species. Analysis of 4 years of subsequent diameter growth showed that the thinned residual trees (1) grew faster than the unthinned ones, (2) generally responded as well as trees after a range of earlier precommercial treatments, and (3) generally responded as well as residual trees after a more conventional thinning conducted in 1936, indicating that potential growth after thinning has not changed materially over the last 60+ years.
31
Lamson, Neil I., H. Clay Smith, and Gary W. Miller. "Logging Damage Using an Individual-Tree Selection Practice in Appalachian Hardwood Stands." Northern Journal of Applied Forestry 2, no. 4 (1985): 117–20. http://dx.doi.org/10.1093/njaf/2.4.117.
Повний текст джерелаАнотація:
Abstract Four West Virginia hardwood stands, managed using individual-tree selection for the past 30 years, were examined after the third and, in one instance, the fourth periodic harvest to determine the severity of logging damage. On existing skid roads, trees were removed with a rubber-tired skidder or a crawler tractor with a rubber-tired arch. Logging damage reduced residual stand basal area by 6%, a total of 6.1 ft² per acre. Damage was concentrated in the saplings—85% of the stems lost to logging damage were less than 5.0 in dbh. An adequate number of undamaged stems in all diameter classes remained after logging to achieve individual-tree selection stand structure goals. North. J. Appl. For. 2:117-120, Dec. 1985.
32
Johnson, James E., Gary W. Miller, John E. Baumgras, and Cynthia D. West. "Assessment of Residual Stand Quality and Regeneration Following Shelterwood Cutting in Central Appalachian Hardwoods." Northern Journal of Applied Forestry 15, no. 4 (1998): 203–10. http://dx.doi.org/10.1093/njaf/15.4.203.
Повний текст джерелаАнотація:
Abstract Partial cutting to develop two-age stands is a relatively new practice in the central Appalachian region, and forest managers need quantitative information in order to evaluate how well it meets management objectives. Typically, this practice leaves a residual overstory of 10 to 40 ft² per ac of basal area and leads to regeneration of desirable shade-intolerant species which comprise the second age class. In this study we evaluated residual tree quality and regeneration 2 to 5 yr after cutting in 20 stands on the Monongahela National Forest in West Virginia. Tree grades were not significantly affected by the cutting. The largest grade reductions, due primarily to epicormic branching and logging wounds, occurred with large white oak sawtimber (11%) and white ash small sawtimber (10%). Epicormic branching following the cut was greatest for white oaks in the suppressed and intermediate crown classes. Across all species, the trees in the lower crown classes produced the greatest number of epicormic branches. Overall, epicormic branching on the 16 ft butt logs of dominant and codominant trees was low. For white oak (Quercus alba), 64% of these trees produced no epicormic branches. But 75% of yellow-poplars (Liriodendron tulipifera), 82% of black cherries (Prunus serotina), 78% of northern red oaks (Quercus rubra), and 89% of white ashes (Fraxinus americana) produced no epicormic branches on butt logs. Logging wounds occurred on 45% of the residual trees across the 20 stands, but 21% had large wounds over 100 in². Regeneration of both shade-intolerant and tolerant species was prolific following the cutting. Total numbers of tree seedlings and sprouts ranged from 8,217 stems/ac in the mixed oak stands of the Ridge and Valley Province to 30,845 stems/ac in the beech-cherry-maple stands in the Allegheny Mountains. The birches, primarily sweet birch (Betula lenta), comprised the most abundant species across the study area, but species composition varied depending on forest cover type. Regeneration numbers were lowest in the mixed oak stands in the Ridge and Valley Province. North. J. Appl. For. 15(4):203-210.
33
Power, Hugues, Patricia Raymond, Marcel Prévost, Vincent Roy, and Frank Berninger. "Basal area and diameter growth in high-graded eastern temperate mixedwood forests: the influence of acceptable growing stock, species, competition and climate." Forestry: An International Journal of Forest Research 92, no. 5 (2019): 659–69. http://dx.doi.org/10.1093/forestry/cpz029.
Повний текст джерелаАнотація:
AbstractHarvesting practices in temperate mixedwoods of eastern North America have a history of diameter-limit cuts, which have often resulted in degraded residual stands. In this study, we examined the factors influencing stand basal area (BA) and tree diameter growth in previously high-graded mixedwood forests, to understand which stands are more likely to recover from high-grading. Over 15 years, we monitored tree growth, recruitment and stem quality of 532 sample plots that were located in high-graded stands of Quebec’s mixedwood forest. We found that diameter growth rates were positively correlated with precipitation-related variables for balsam fir (Abies balsamea) and for yellow birch (Betulla alleghaniensis) but opposing trends for temperature-related variables were found. Conversely to balsam fir, yellow birch growth was positively correlated to temperature variables. Our results also show that BA growth was greater for plots with a larger acceptable growing stock (AGS: trees with potential sawlog production) and that the increase in AGS was greater for plots with larger amount of conifer BA. These result highlights the importance to maintain a proportion of conifer trees in these mixed stands. Moreover, the significant effect of asymmetric competition in our study underscores the relevance of considering the spatial distribution when choosing crop trees.
34
Brandeis, Thomas J., and Consuelo Brandeis. "Assessing Tree Mortality Probability in Harvested Hardwood Stands Using Long-Term Forest Inventory Data." Forest Science 67, no. 2 (2021): 231–40. http://dx.doi.org/10.1093/forsci/fxaa053.
Повний текст джерелаАнотація:
Abstract Partial harvesting (here defined as removal of ≤50% of preharvest volume) is the predominant silvicultural scheme applied to hardwood forest types in the eastern United States. Future stand conditions are largely reliant on trees retained after harvest, so their mortality because of harvesting activity damage should be minimized or taken into account when planning. We quantify partially harvested stand characteristics and postharvest mortality using data from 32,057 forested conditions, 366,953 trees with a diameter at breast height (dbh) ≥ 2.5 cm, of which 4,469 trees were cut and used in partially harvested stands. On average 23.3% of stand volume was selectively harvested with an additional 2.5% of volume lost to harvesting-caused mortality. Of the trees killed by logging activity in harvested stands, 90.7% were under 28 cm dbh. The likelihood of mortality was 1.31 times higher (95% CI of 1.20 to 1.44) for trees retained in stands that had undergone partial harvesting than for trees growing in unharvested stands. Commercial species had lower odds of mortality (0.88 times) in harvested stands than noncommercial species. Residual trees in harvested stands on private lands had a higher probability of mortality (1.23 times) than those on harvested public lands.
35
Lazaruk, Lance W., Gavin Kernaghan, S. Ellen Macdonald, and Damase Khasa. "Effects of partial cutting on the ectomycorrhizae of Picea glauca forests in northwestern Alberta." Canadian Journal of Forest Research 35, no. 6 (2005): 1442–54. http://dx.doi.org/10.1139/x05-062.
Повний текст джерелаАнотація:
This study assessed the impact of various harvesting practices (including those designed to emulate natural disturbances) on ectomycorrhizae (ECM) associated with white spruce (Picea glauca (Moench) Voss) in northwestern Alberta, Canada. Treatments included clearcuts, partial cuts (dispersed green-tree retention with 20%, 50%, and 75% residual live trees, and aggregated green-tree retention), unharvested control sites, and a burned stand. The percentage of active white spruce root tips and ECM richness and diversity, as observed in soil cores collected throughout the study site, all decreased with increasing disturbance intensity. Effects were particularly pronounced in clearcuts, machine corridors used for access by harvesting equipment in the dispersed green-tree retention stands, and in burned areas. Reductions in ECM biodiversity could be attributed to the sensitivity of late-stage ectomycorrhizae (e.g., Cortinarius spp., Lactarius spp., and Russula spp.) to soil disturbances and changes in microclimate associated with harvesting or burning. Areas of dispersed and aggregated green-tree retention were not dramatically different than unharvested forest in terms of root tip density and ECM richness, diversity, and composition. Harvesting practices that retain a percentage of residual live trees, either dispersed throughout the cutting unit or in aggregated patches, could be an effective means of maintaining ectomycorrhizal biodiversity at the stand level.
36
Greene, D. F., and E. A. Johnson. "Tree recruitment from burn edges." Canadian Journal of Forest Research 30, no. 8 (2000): 1264–74. http://dx.doi.org/10.1139/x00-040.
Повний текст джерелаАнотація:
We developed and tested a wind-dispersal model of tree recruitment into burns from living sources at the fire edge or from small unburned residual stands. The model was also tested on recruitment of serotinous Pinus banksiana Lamb. within a burn. The model assumed that source strength is proportional to basal area density and that an individual (point source) recruitment curve can be expressed as a lognormal distribution. The model made significant predictions of the recruitment curves of Engelmann spruce (Picea engelmannii Parry ex Engelm.), white spruce (Picea glauca (Moench) Voss), and balsam fir (Abies balsamea (L.) Mill.) to distances as great as 2.0 km, although it tended to underpredict Abies and overpredict Picea. The model gave significant prediction of recruitment for jack pine (Pinus banksiana) within burns with seeds derived from aerial seed banks, and of white spruce and tamarck (Larix laricina (Du Roi) K. Koch) up to 100 m from residual stands. By forestry standards, burns are poorly stocked by those species that must obligately recruit from edges. In large fires, adequate stocking by a species such as white spruce that had 5 m2/ha of basal area would be limited to about 70 m from the edge. Small residual stands are expected to supply about half of all the recruits of white spruce or fir at distances exceeding about 800 m from a nominal burn edge.
37
Hansen, E. Matthew, José F. Negron, A. Steven Munson, and John A. Anhold. "A Retrospective Assessment of Partial Cutting to Reduce Spruce Beetle-Caused Mortality in the Southern Rocky Mountains." Western Journal of Applied Forestry 25, no. 2 (2010): 81–87. http://dx.doi.org/10.1093/wjaf/25.2.81.
Повний текст джерелаАнотація:
Abstract Tree susceptibility to bark beetle-caused mortality has been linked to stand characteristics such as basal area (BA) and average tree size, factors that can be manipulated through partial cutting. There is no experimental evidence, however, demonstrating the efficacy of partial cutting in spruce type. Such experiments are very difficult to complete because of the inability to manipulate bark beetle populations needed to challenge treated stands. To circumvent this difficulty, we identified spruce stands that were partially cut (for nonexperimental reasons) in advance ofbeetle activity and compared beetle-caused mortality to that in nearby spruce stands that were not treated. Treated stands had fewer infested stems and less infested BA than untreated stands, as well as smaller proportions of infested stems and BA. Untreated stands, however, had more residualspruce stems and BA than treated stands. Most of this difference was among stems 3–11 in. dbh with little difference in survivorship among larger stems. Spruce regeneration was not significantly different among treated and untreated stands. Spruce stand density index, spruce BA, and the number of spruce stems >11 in. dbh were the stand variables most strongly correlated with host mortality measurements. Insect population pressure appears to influence the degree of protection to residual spruce following partial cutting.
38
Piri, Tuula, and Kari Korhonen. "The effect of winter thinning on the spread of Heterobasidion parviporum in Norway spruce stands." Canadian Journal of Forest Research 38, no. 10 (2008): 2589–95. http://dx.doi.org/10.1139/x08-103.
Повний текст джерелаАнотація:
Genets of Heterobasidion were identified in eight 43- to 56-year-old Norway spruce ( Picea abies (L.) Karst.) stands in southern Finland. Four of the stands had been thinned in winter ca. 10 years prior to the study, and four had been left unthinned. It was hypothesized that the felling of decayed trees promotes the vegetative spread of the fungus from thinning stumps into the adjacent trees, and hence the Heterobasidion genets should be larger in thinned stands. Although the number of infected stumps per areal unit was lower and the genets were slightly smaller in the previous tree generation of thinned plots, the genets, particularly the old ones, in the present tree generation were larger on thinned plots. The genets originating from the previous rotation included, on average, 12.2 trees on thinned plots and 6.7 trees on unthinned plots. The mean number of trees infected by new genets (not found in previous generation) was also slightly higher (p < 0.05) on thinned than on unthinned plots, 1.8 and 1.2 trees, respectively. The results indicate that the rapid expansion of old Heterobasidion infections after a thinning operation may significantly contribute to the occurrence of root rot in the residual stand.
39
Emmingham, Wm, Rick Fletcher, Stephen Fitzgerald, and Max Bennett. "Comparing Tree and Stand Volume Growth Response to Low and Crown Thinning in Young Natural Douglas-fir Stands." Western Journal of Applied Forestry 22, no. 2 (2007): 124–33. http://dx.doi.org/10.1093/wjaf/22.2.124.
Повний текст джерелаАнотація:
Abstract We consider tree and stand response to low, crown, and no thinningof well-differentiated, naturally regenerated even-aged Douglas-firstands over 15 years on a moderately productive Cascade Mountains siteand over 10 years on a highly productive Oregon Coast Range site.Regardless of treatment, trees in dominant and codominant crown classescontinued growing at preinitiation rates and contributed 92–100% ofstand growth 5–15 years later. Most leave trees in suppressed crownclasses died during the first 10 years and suppressed and intermediatecrown classes contributed little to stand growth because survivorscontinued to grow slowly. Low thinning remains the most reliablethinning method for increasing stand volume in high-quality trees.Crown or selection thinning may be used to achieve certain objectivesif managers carefully use information about response of trees invarious crown classes. Growth rates of residual stands will depend onthe amount of residual growing stock and the degree to which it iscomprised of vigorously growing dominant and codominant trees.Residual subordinate trees may provide snags but few living trees insmall-diameter classes. Implications for management of the Douglas-firare discussed.
40
Baker, James B., and Michael G. Shelton. "Rehabilitation of Understocked Loblolly-Shortleaf Pine Stands—I. Recently Cutover Natural Stands." Southern Journal of Applied Forestry 22, no. 1 (1998): 35–40. http://dx.doi.org/10.1093/sjaf/22.1.35.
Повний текст джерелаАнотація:
Abstract Two loblolly-shortleaf pine (Pinus taeda L.-P. echinata Mill.) stands were cut to stocking levels of 10, 20, 30, 40, and 50% to simulate recently cutover, understocked, uneven-aged stands. Number of trees ranged from 38 per acre for 10% stocking to 213 per acre for 50% stocking; comparable total basal areas were 4 and 16 ft²/ac, respectively. One stand was on a good site (site index = 90 ft at age 50), the other on a medium site (site index = 75 ft at age 50). As a rehabilitation treatment, all hardwoods 1 in. groundline diameter and larger were injected with a herbicide. At 2, 5, 10, and 15 yr after treatment, the stands were inventoried to determine: (1) rate at which the understocked stands recovered, and (2) minimum stocking levels required for successful rehabilitation. During 15 yr of rehabilitation, the understocked stands changed dramatically, and because of rapid growth of residual pines, stocking levels, basal areas, and tree volumes increasedmarkedly. Stands having at least 20% residual stocking and 5 ft²/ac of pine basal area reached an acceptable stocking level of 60% (based on number and size of trees), or 45 ft²/ac of basal area within 15 yr. Stands at this minimum stocking threshold produced 4,600 bd ft(Doyle)/ac of sawtimber volume on the good site and 3,000 bd ft/ac of sawtimber volume on the medium site during the 15 yr period. The study indicates that recently cutover, or damaged, understocked stands with at least 20% to 30% stocking or 5 to 10 ft²/ac of pine basal area can be rehabilitated to produce respectable sawtimber volumes. This management strategy provides a low-cost alternative to establishing a new stand at considerable cost to the landowner. South. J. Appl. For. 22(1):35-40.
41
McGee, Gregory G., and Robin W. Kimmerer. "Forest age and management effects on epiphytic bryophyte communities in Adirondack northern hardwood forests, New York, U.S.A." Canadian Journal of Forest Research 32, no. 9 (2002): 1562–76. http://dx.doi.org/10.1139/x02-083.
Повний текст джерелаАнотація:
The objective of this study was to assess the influence of substrate heterogeneity on epiphytic bryophyte communities in northern hardwood forests of varying disturbance histories. Specifically, we compared bryophyte abundance (m2·ha1) and community composition among partially cut; maturing, 90- to 100-year-old, even-aged; and old-growth northern hardwood stands in Adirondack Park, New York, U.S.A. Total bryophyte cover from 0 to 1.5 m above ground level on trees [Formula: see text]10 cm diameter at breast height (DBH) did not differ among the three stand types. However, bryophyte community composition differed among host tree species and among stand types. Communities in partially cut and maturing stands were dominated by xerophytic bryophytes (Platygyrium repens, Frullania eboracensis, Hypnum pallescens, Brachythecium reflexum, Ulota crispa), while old-growth stands contained a greater representation of calcicoles and mesophytic species (Brachythecium oxycladon, Anomodon rugelii, Porella platyphylloidea, Anomodon attenuatus, Leucodon brachypus, Neckera pennata). This mesophyte-calcicole assemblage occurred in all stand types but was limited by the abundance of large-diameter (>50 cm DBH), thick-barked, hardwood host trees (Acer saccharum Marsh., Tilia americana L., Fraxinus americana L.). This study suggested that epiphytic bryophyte diversity can be sustained and enhanced in managed northern hardwood forests by maintaining host tree species diversity and retaining large or old, thick-barked residual hardwood stems when applying even-aged and uneven-aged silviculture systems.
42
Yuniawati, Yuniawati, S. Andini, and M. H. Ningrum. "Application of Conventional and Improved Techniques in Felling and Skidding to Residual Stand Damages." Jurnal Manajemen Hutan Tropika (Journal of Tropical Forest Management) 29, no. 3 (2023): 234–42. http://dx.doi.org/10.7226/jtfm.29.3.234.
Повний текст джерелаАнотація:
Felling and skidding are essential in the timber extraction process. But on the other hand, residual stand damage can’t be avoided. This study aimed to analyze the impact of conventional and improved felling and skidding techniques on residual stands in natural forests. Three observation plots were developed to identify the types, numbers, and criteria of residual stand damage due to both techniques. The criteria were categorized as a) minor damage (<25%), b) moderate damage (25–50%), and c) major damage (>50%). It showed that the conventional felling and skidding technique caused damages of 14.92% dominated by tree crown damage and 16.70% dominated by stem wounds, respectively. The residual stand damage due to conventional felling and skidding technique was 31.62% categorized as medium damage. Meanwhile, improved felling and skidding techniques caused damage of 9.89% dominated by broken trees, and 10.27% dominated by stem wounds, respectively. The residual stand damage due to improved felling and skidding technique was 20.16% categorized as minor damage. The improvement techniques can minimize residual stand damage by 36.24%. Therefore, a good understanding of forest concessionaires regarding RIL principles is necessary for achieving sustainable timber harvesting
43
Fowler, Gary W. "Individual Tree Volume Equations for Red Pine in Michigan." Northern Journal of Applied Forestry 14, no. 2 (1997): 53–58. http://dx.doi.org/10.1093/njaf/14.2.53.
Повний текст джерелаАнотація:
Abstract New total, pulpwood, sawtimber, and residual pulpwood cubic foot individual tree volume equations were developed for red pine in Michigan using nonlinear and multiple linear regression. Equations were also developed for Doyle, International 1/4 in., and Scribner bd ft volume, and a procedure for estimating pulpwood and residual pulpwood rough cord volumes from the appropriate cubic foot equations was described. Average ratios of residual pulpwood (i.e., topwood, cubic foot or cords) to mbf were developed for 7.6 and 9.6 in. sawtimber. Data used to develop these equations were collected during May-August 1983-1985 from 3,507 felled and/or standing trees from 27 stands in Michigan. Sixteen and 11 stands were located in the Upper and Lower Peninsulas, respectively. All equations were validated on an independent data set. Rough cord volume estimates based on the new pulpwood equation were compared with contemporary tables for 2 small cruise data sets. The new equations can be used to more accurately estimate total volume and volume per acre when cruising red pine stands. North. J. Appl. For. 14(2):53-58.
44
Behjou, Farshad Keivan, and Alireza Ghomi Motazeh. "Residual Trees Response to Selective Cutting Operations in Caspian Forests." Nova mehanizacija šumarstva 41 (December 10, 2020): 29–35. http://dx.doi.org/10.5552/nms.2020.4.
Повний текст джерелаАнотація:
Damages to residual trees caused by felling operation were assessed in the stands of a Caspian hardwood forest. Following the felling operation, a field survey was done to collect data of all residual trees (species, DBH, height) and of tree wounds (size class, location, intensity of damage). Different harvesting intensities were studied, and treatments were replicated three times. The results showed that the treatment with the medium and high harvest intensity was found to cause the highest percentage of damage and the largest stem wounds. It is concluded that harvesting intensity should be limited to 3 trees/ha during each harvesting operation to reduce the extent of tree damage and thus future financial loss.
45
Liang, Jingjing, Joseph Buongiorno, and Robert A. Monserud. "Bootstrap Simulation and Response Surface Optimization of Management Regimes for Douglas-Fir/Western Hemlock Stands." Forest Science 52, no. 5 (2006): 579–94. http://dx.doi.org/10.1093/forestscience/52.5.579.
Повний текст джерелаАнотація:
Abstract A method was proposed to simulate forest stand growth, timber prices, and interest rates by distribution-free bootstrapping, and then optimize management controls for economic and ecological objectives by response surface analysis. The method was applied to Douglas-fir/western hemlock stands to predict the effects on economic and ecological objectives of management alternatives defined by the cutting cycle, C, the residual stand basal area, B, the diameter of the largest tree, D, and the ratio, q, of the number of trees in adjacent diameter classes. The effects were described with response surfaces, which were used to determine the best combinations of B, q, and C for each management criterion. Adjusting B, q, and C could control for 97 to 99% of the variability in the expected value of species diversity, size diversity, percentage of peeler logs, and basal area, and for 80 to 90% of the variability in land expectation value and annual production. Economic and ecologic criteria were generally most sensitive to the q ratio, the residual basal area, and the cutting cycle. Annual production was negatively correlated with tree size diversity and wood quality. There was no apparent conflict between stand diversity and wood quality.
46
Cimon-Morin, Jérôme, Jean-Claude Ruel, Marcel Darveau, Jean-Martin Lussier, Philippe Meek, and Vincent Roy. "Essais de jardinage sans martelage dans des peuplements irréguliers de sapin baumier et d’épinette noire." Forestry Chronicle 86, no. 4 (2010): 498–510. http://dx.doi.org/10.5558/tfc86498-4.
Повний текст джерелаАнотація:
It is increasingly accepted that silviculture must now try to maintain complex stands. In this context, selection cutting has been suggested as an option for irregular boreal stands. However, selection cutting in virgin stands could prove difficult to apply at a reasonable cost. In an attempt to reduce harvesting costs, two selection cutting patterns were implemented, avoiding tree marking. The efficacy of this approach was evaluated by comparing the results of plots harvested without tree marking to those with tree marking. To proceed in the absence of tree marking, silvicultural types were defined as well as a rule for the selection of stems to harvest; the final choice of stems to fell was therefore left to the operator upon harvesting. The effects of the different silvicultural and tree marking treatments were examined in relation to their ability to maintain the main structural and functional attributes of irregular boreal stands. A follow-up was conducted with regards to structure, composition, residual stand basal area, abundance of woody debris and mortality. The absence of marking did not affect the performance of selection cutting treatments in terms of basal area, quadratic mean diameter and Shannon index. Tree vigour was not modified by harvesting, both with and without tree marking. Stand composition was not influenced by the absence of marking. Snag abundance was reduced to similar levels regardless of marking. Tree marking did not influence the abundance of downed woody debris. As a consequence, it seems possible to apply a simplified approach of selection cutting, without compromising the success of the treatment in these stands.Key words: black spruce, Picea mariana, balsam fir, Abies balsamea, irregular stand, selection cutting, ecosystem management, forest attributes
47
Bakys, R., R. Vasaitis, and J. P. Skovsgaard. "Patterns and severity of crown dieback in young even-aged stands of european ash (Fraxinus excelsior L.) in relation to stand density, bud flushing phenotype, and season." Plant Protection Science 49, No. 3 (2013): 120–26. http://dx.doi.org/10.17221/70/2012-pps.
Повний текст джерелаАнотація:
The extent and temporal pattern of crown damage (attributed to Hymenoscyphus pseudoalbidus) in even-aged stands of Fraxinus excelsior in relation to bud flushing phenotype, stand density, and season was investigated. Data were collected in 2007 in four statistically designed thinning experiments located in 12&ndash;15-years old plantations of ash in Denmark. The study included 21 plots of four contrasting, residual stand densities: (1) 1700&ndash;5500 trees/ha (unthinned control plots), (2)&nbsp;1500 trees/ha, (3) 500 trees/ha, and (4) 100&ndash;150 trees/ha. Assessments included estimation of flushing phenotype in May, followed by evaluation of severity of crown damage (percentage of crown killed) in June and September. Simultaneously, for each tree, the presence or absence of crown wilt and dead tops were recorded. The seasonal pattern of disease severity (average crown damage) was similar in all stands, and disregarding stand density the extent of tree crown damage increased significantly towards the end of the growing season (P &lt; 0.005). Disease severity was the worst in unthinned plots, but otherwise unrelated to stand density. Late-flushing trees were most severely affected (P &lt; 0.001). The observed patterns of disease severity are probably associated with ecological features of the pathogen that still remain largely unknown. &nbsp;
48
Cline, Michael L., Benjamin F. Hoffman, Michael Cyr, and William Bragg. "Stand Damage Following Whole-Tree Partial Cutting in Northern Forests." Northern Journal of Applied Forestry 8, no. 2 (1991): 72–76. http://dx.doi.org/10.1093/njaf/8.2.72.
Повний текст джерелаАнотація:
Abstract Eighteen mechanically harvested, partially cut hard- and mixed-wood stands in New England were examined to determine the extent of logging damage. Frequency of crop tree damage averaged 9.6%. Tree injury, both incidence and severity, was not related to location relative to skid trails or landings. Variations in damage level between sites was not explained by numbers of trees per acre, size of trees, or basal area prior to or after harvest, but cover type, rockiness, and season of harvest in combination accounted for a small part of the site-to-site differences. Residual stand damage appeared to be most influenced by the care in harvest planning and the experience of the equipment operators. North. J. Appl. For. 8(2):72-76.
49
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 (2019): 1015. http://dx.doi.org/10.3390/f10111015.
Повний текст джерелаАнотація:
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.
50
Kizha, Anil Raj, Evan Nahor, Noah Coogen, Libin T. Louis, and Alex K. George. "Residual Stand Damage under Different Harvesting Methods and Mitigation Strategies." Sustainability 13, no. 14 (2021): 7641. http://dx.doi.org/10.3390/su13147641.
Повний текст джерелаАнотація:
A major component of sustainable forest management are the stands left behind after the logging operation. Large mechanized harvesting equipment involved in current forest management can inflict damage on residual trees; and can pose a risk of mortality from diseases, natural calamities, and/or degrade future economic value. The primary objective of this study was to evaluate the residual stand damage under different harvesting methods and silvicultural prescriptions i.e., crop tree release (CTR), diameter limit cut (DLC), and overstory removal (OSR). The second objective was to evaluate the intensity and frequency of damage occurring on the bole, canopy, and root at tree and stand level. The third objective was to document strategies adopted globally to minimize stand damage due to timber harvesting. Five harvest blocks implementing three silvicultural prescriptions, were selected as the treatments across two different industrial timberlands in central and northern Maine (Study Site (SS) I and II, respectively). A hybrid cut-to-length (Hyb CTL) and whole-tree (WT) harvesting method were employed for conducting the harvest in SS I and II, respectively. Systematic transect sampling was employed to collect information on type, frequency, and intensity of damages. The inventory captured 41 and 8 damaged trees per hectare with 62 and 22 damages per hectare from SS I and SS II respectively. Bole damage was the most frequent damage across all treatments. The Hyb CTL had lower damage density (damage per ha) and severity compared to WT. The average number of trees damaged per ha was higher for CTR prescriptions compared to DLC. There were no significant differences in the height of the damages from the ground level between treatments within each study site; however, there was a significant difference between the study sites. Species damaged was directly related to the residual trees left behind and was dominated by American beech, yellow birch, sugar maple, and eastern hemlock. Finally, the study provides strategies that can be adopted at different forest managerial phases to mitigate residual stand damage.