Pub Date : 2024-04-10DOI: 10.1093/forestscience/52.5.579
Jingjing Liang, Joseph Buongiorno, Robert A. Monserud
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.
提出了一种方法，通过无分布引导法模拟林分生长、木材价格和利率，然后通过响应面分析法优化经济和生态目标的管理控制。该方法应用于花旗松/西部铁杉林分，预测由砍伐周期 C、剩余林分基部面积 B、最大树木直径 D 和相邻直径等级树木数量比 q 定义的管理替代方案对经济和生态目标的影响。通过响应曲面来描述这些影响，从而确定每种管理标准下 B、q 和 C 的最佳组合。调整 B、q 和 C 可以控制物种多样性、大小多样性、剥皮原木百分比和基部面积预期值中 97% 到 99% 的变化，以及土地预期值和年产量中 80% 到 90% 的变化。经济和生态标准通常对 q 比率、剩余基部面积和砍伐周期最为敏感。年产量与树木大小多样性和木材质量呈负相关。林分多样性与木材质量之间没有明显的冲突。
{"title":"Bootstrap Simulation and Response Surface Optimization of Management Regimes for Douglas-Fir/Western Hemlock Stands","authors":"Jingjing Liang, Joseph Buongiorno, Robert A. Monserud","doi":"10.1093/forestscience/52.5.579","DOIUrl":"https://doi.org/10.1093/forestscience/52.5.579","url":null,"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.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"30 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140566615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-10DOI: 10.1093/forestscience/57.6.506
Weifeng Wang, Xiangdong Lei, Zhihai Ma, Daniel D. Kneeshaw, Changhui Peng
Maintaining both the structure and functionality of forest ecosystems is a primary goal of forest management. In this study, relationships between structural diversity and aboveground stand carbon (C) stocks were examined in spruce-dominated forests in New Brunswick, Canada. Tree species, size, and height diversity indices as well as a combination of these diversity indices were used to correlate aboveground C stocks. Multiple linear regressions were subsequently used to quantify the relationships between these indices and aboveground C stocks, and partial correlation analysis was also adopted to remove the effects of other explanatory variables. Results show that stand structural diversity has a significant positive effect on aboveground C stocks even though the relationship is weak overall. Positive relationships observed between the diversity indices and aboveground C stocks support the hypothesis that increased structural diversity enhances aboveground C storage capacity. This occurs because complex forest structures allow for greater light infiltration and promote a more efficient resource use by trees, leading to an increase in biomass and C production. Mixed tolerant species composition and uneven-aged stand management in conjunction with selection or partial cutting to maintain high structural diversity is therefore recommended to preserve biodiversity and C stocks in spruce-dominated forests.
{"title":"Positive Relationship between Aboveground Carbon Stocks and Structural Diversity in Spruce-Dominated Forest Stands in New Brunswick, Canada","authors":"Weifeng Wang, Xiangdong Lei, Zhihai Ma, Daniel D. Kneeshaw, Changhui Peng","doi":"10.1093/forestscience/57.6.506","DOIUrl":"https://doi.org/10.1093/forestscience/57.6.506","url":null,"abstract":"Maintaining both the structure and functionality of forest ecosystems is a primary goal of forest management. In this study, relationships between structural diversity and aboveground stand carbon (C) stocks were examined in spruce-dominated forests in New Brunswick, Canada. Tree species, size, and height diversity indices as well as a combination of these diversity indices were used to correlate aboveground C stocks. Multiple linear regressions were subsequently used to quantify the relationships between these indices and aboveground C stocks, and partial correlation analysis was also adopted to remove the effects of other explanatory variables. Results show that stand structural diversity has a significant positive effect on aboveground C stocks even though the relationship is weak overall. Positive relationships observed between the diversity indices and aboveground C stocks support the hypothesis that increased structural diversity enhances aboveground C storage capacity. This occurs because complex forest structures allow for greater light infiltration and promote a more efficient resource use by trees, leading to an increase in biomass and C production. Mixed tolerant species composition and uneven-aged stand management in conjunction with selection or partial cutting to maintain high structural diversity is therefore recommended to preserve biodiversity and C stocks in spruce-dominated forests.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"18 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140566228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-10DOI: 10.1093/forestscience/55.2.142
Zhongsheng Wang, Hong Liu, Na Wei, Weixiang Xu, Shuqing An, Shirong Liu
As a representative relict forest type, the sclerophyllous oak (Quercus aquifolioides Rehd. et Wils.) forests in the Himalayas-Hengduanshan Mountains of China have been either nearly completely destroyed or heavily fragmented, mostly due to the long-lasting overexploitation by local human population. To evaluate the effect of current silvicultural treatments on regeneration of sclerophyllous oak, we compared inter simple sequence repeats, measures of genetic variation of this species regenerating in three types of stands: natural old-growth oak forest, clearcut spruce plantation, and clearcut naturally regenerated stands in the Miyaluo area, western Sichuan Province of China. Results showed that populations of Q. aquifolioides in the old-growth stands displayed the highest level of genetic diversity, whereas populations in the clearcut naturally regenerated stands had the lowest. In addition, we found that populations in the older spruce plantations (e.g., stands ≥50 years old) were genetically more diverse than those in the younger sites. These findings had the following immediate implications: forest clearcuts had significantly reduced genetic variability within populations of Q. aquifolioides; artificial reforestation of spruce after clearcut could promote the recovery of genetic diversity in Q. aquifolioides, especially in the older stands; and severe human and livestock disturbances hindered the recovery of genetic diversity of Q. aquifolioides in the naturally regenerated stands. We recommend active thinning in spruce plantations (at approximately age 30-40 years) via selective logging at times of rapid height growth and crown closure to promote multistoried stand structures and canopy gaps suitable for the survival and growth of Q. aquifolioides. Finally, we recommend strict management control in the naturally regenerated stands to limit the utilities of these stands by humans and their livestock to facilitate the recovery of Q. aquifolioides genetic diversity.
作为一种具有代表性的孑遗森林类型，中国喜马拉雅山-横断山的硬叶栎森林（Quercus aquifolioides Rehd. et Wils.）已几乎被完全破坏或严重破碎，这主要是由于当地人类的长期过度开发造成的。为了评估目前的造林措施对硬叶栎再生的影响，我们比较了简单序列重复序列间的遗传变异，以及该物种在中国四川省西部米亚罗地区三种林分中再生的遗传变异情况：天然老龄栎林、人工云杉林和天然更新林分。结果表明，古老林分中的水曲柳种群遗传多样性水平最高，而天然更新林分中的种群遗传多样性水平最低。此外，我们还发现老云杉人工林（如树龄≥50年的林分）中的种群比年轻林分中的种群遗传多样性更高。这些发现具有以下直接影响：森林砍伐大大降低了水曲柳种群内的遗传变异性；砍伐后云杉的人工再造林可促进水曲柳遗传多样性的恢复，尤其是在树龄较大的林分中；严重的人为和牲畜干扰阻碍了自然再生林分中水曲柳遗传多样性的恢复。我们建议在云杉人工林中积极疏伐（树龄约为 30-40 年），在高度快速增长和树冠闭合时选择性伐木，以促进适合水曲柳生存和生长的多层林分结构和树冠间隙。最后，我们建议对自然再生的林分进行严格的管理控制，限制人类及其牲畜对这些林分的利用，以促进水曲柳遗传多样性的恢复。
{"title":"Effects of Stand Regeneration Management Regimes and Age on Genetic Structure of Quercus aquifolioides (Sclerophyllous Oak) in Southwestern China","authors":"Zhongsheng Wang, Hong Liu, Na Wei, Weixiang Xu, Shuqing An, Shirong Liu","doi":"10.1093/forestscience/55.2.142","DOIUrl":"https://doi.org/10.1093/forestscience/55.2.142","url":null,"abstract":"As a representative relict forest type, the sclerophyllous oak (Quercus aquifolioides Rehd. et Wils.) forests in the Himalayas-Hengduanshan Mountains of China have been either nearly completely destroyed or heavily fragmented, mostly due to the long-lasting overexploitation by local human population. To evaluate the effect of current silvicultural treatments on regeneration of sclerophyllous oak, we compared inter simple sequence repeats, measures of genetic variation of this species regenerating in three types of stands: natural old-growth oak forest, clearcut spruce plantation, and clearcut naturally regenerated stands in the Miyaluo area, western Sichuan Province of China. Results showed that populations of Q. aquifolioides in the old-growth stands displayed the highest level of genetic diversity, whereas populations in the clearcut naturally regenerated stands had the lowest. In addition, we found that populations in the older spruce plantations (e.g., stands ≥50 years old) were genetically more diverse than those in the younger sites. These findings had the following immediate implications: forest clearcuts had significantly reduced genetic variability within populations of Q. aquifolioides; artificial reforestation of spruce after clearcut could promote the recovery of genetic diversity in Q. aquifolioides, especially in the older stands; and severe human and livestock disturbances hindered the recovery of genetic diversity of Q. aquifolioides in the naturally regenerated stands. We recommend active thinning in spruce plantations (at approximately age 30-40 years) via selective logging at times of rapid height growth and crown closure to promote multistoried stand structures and canopy gaps suitable for the survival and growth of Q. aquifolioides. Finally, we recommend strict management control in the naturally regenerated stands to limit the utilities of these stands by humans and their livestock to facilitate the recovery of Q. aquifolioides genetic diversity.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"39 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140566300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-10DOI: 10.1093/forestscience/37.4.987
J. B. St. Clair, W. T. Adams
Seed weight, time of emergence, and three measures of seedling size were recorded for 39 open-pollinated Douglas-fir (Pseudotsuga menziesii vat. menziesii [Mirb.] Franco) families in order to assess family variation in seed weight and emergence, and the influence of these seed traits on early growth. Families were planted both as ungerminated seed and as recent germinants to test whether using germinants minimized seed effects on early growth. To evaluate the effect of competition on the relationships of seed weight and rate of emergence to seedling size, individuals of families were planted in mixed-family blocks at close spacing, in single (pure) family blocks at close spacing, and at a wide, noncompetitive spacing. Families differed significantly in seed weight, total percent emergence, and rate of emergence. Nevertheless, correlations of seed weight to rate of emergence, and seed weight and rate of emergence to seedling size were not strong. Using germinants was ineffective in diminishing seed effects, and interfamily competition had only a minor influence on magnifying seed effects. For. Sci. 37(4):987-997.
{"title":"Effects of Seed Weight and Rate of Emergence on Early Growth of Open-Pollinated Douglas-Fir Families","authors":"J. B. St. Clair, W. T. Adams","doi":"10.1093/forestscience/37.4.987","DOIUrl":"https://doi.org/10.1093/forestscience/37.4.987","url":null,"abstract":"Seed weight, time of emergence, and three measures of seedling size were recorded for 39 open-pollinated Douglas-fir (Pseudotsuga menziesii vat. menziesii [Mirb.] Franco) families in order to assess family variation in seed weight and emergence, and the influence of these seed traits on early growth. Families were planted both as ungerminated seed and as recent germinants to test whether using germinants minimized seed effects on early growth. To evaluate the effect of competition on the relationships of seed weight and rate of emergence to seedling size, individuals of families were planted in mixed-family blocks at close spacing, in single (pure) family blocks at close spacing, and at a wide, noncompetitive spacing. Families differed significantly in seed weight, total percent emergence, and rate of emergence. Nevertheless, correlations of seed weight to rate of emergence, and seed weight and rate of emergence to seedling size were not strong. Using germinants was ineffective in diminishing seed effects, and interfamily competition had only a minor influence on magnifying seed effects. For. Sci. 37(4):987-997.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"2 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140566636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-10DOI: 10.1093/forestscience/52.5.549
Susanna Laaksonen-Craig, Jussi Uusivuori
This article examines the impacts of research and development on the mode of multinational expansion (exports versus foreign sales) by forest products companies, and the effects of firms' international strategy on the level of research and development investments. A theoretical model of imperfect competition between international companies is derived and company-level data representing Finnish forest industries are used. The results indicate that the firms' own research and development investments helped, at least during the 1980s, their foreign expansion by favoring the firms' exports rather than foreign sales. External research and development investments by other companies were substitutes for a firm's own investment on research and development in the 1980s, but this effect seems to have disappeared toward the 1990s. There have not appeared to be any significant spillover effects from the research and development activities across the firms.
{"title":"Research and Development Operations and Foreign Expansion of Multinational Companies: Evidence from Forest Industry Microdata","authors":"Susanna Laaksonen-Craig, Jussi Uusivuori","doi":"10.1093/forestscience/52.5.549","DOIUrl":"https://doi.org/10.1093/forestscience/52.5.549","url":null,"abstract":"This article examines the impacts of research and development on the mode of multinational expansion (exports versus foreign sales) by forest products companies, and the effects of firms' international strategy on the level of research and development investments. A theoretical model of imperfect competition between international companies is derived and company-level data representing Finnish forest industries are used. The results indicate that the firms' own research and development investments helped, at least during the 1980s, their foreign expansion by favoring the firms' exports rather than foreign sales. External research and development investments by other companies were substitutes for a firm's own investment on research and development in the 1980s, but this effect seems to have disappeared toward the 1990s. There have not appeared to be any significant spillover effects from the research and development activities across the firms.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"52 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140566085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-10DOI: 10.1093/forestscience/38.1.95
R. J. Haines, T. R. Copley, J. R. Huth, M. R. Nester
Several morphological features were significantly related to the rooting response, and subsequent field performance as rooted cuttings, of shoots collected from hedged stool plants of an F1 hybrid between Pinus caribaea var. hondurensis and P. tecunumanii. Results indicate that it will be possible to manipulate rooting and field performance by shoot selection at the time of harvest of cuttings. The cutting which best meets the objective of maximum rooting without loss of field performance is the terminal segment from a shoot over 30 cm in length, with an actively growing juvenile bud, primary needles in excess of 25 mm, secondary needles present but less than 10 mm in length, and basal diameter over 2 mm. The use of second and third segments of shoots, where these have the appropriate features, would permit greater utilization of material with only a minor decrease in rooting. Primary needle length was the best morphological predictor of both rooting and field height growth. Significant positive genetic correlations suggest that within-family selection for primary needle length will involve selection for clones which root well and which display good height growth in the field, perhaps as a result of slower stool plant aging. For. Sci. 38(1):95-101.
从卡里巴松（Pinus caribaea var. hondurensis）和特库努曼松（P. tecunumanii）的 F1 代杂交种树篱凳植株上采集的嫩枝的生根反应和随后的田间扦插生根表现与几个形态特征有明显关系。结果表明，在收获插条时，可以通过选择插条来控制生根和田间表现。最能满足最大限度生根而不降低田间表现这一目标的插条是长度超过 30 厘米、幼芽生长活跃、主针超过 25 毫米、副针存在但长度小于 10 毫米、基部直径超过 2 毫米的嫩枝顶端部分。如果嫩枝的第二段和第三段具有相应的特征，则可以更多地利用这些材料，而生根率只会略有下降。主针叶长度是预测生根和田间高度增长的最佳形态指标。显著的正遗传相关性表明，对主针叶长度的科内选择将包括选择生根良好、田间高度生长良好的克隆，这可能是茎株老化较慢的结果。科学。科学》38（1）：95-101。
{"title":"Shoot Selection and the Rooting and Field Performance of Tropical Pine Cuttings","authors":"R. J. Haines, T. R. Copley, J. R. Huth, M. R. Nester","doi":"10.1093/forestscience/38.1.95","DOIUrl":"https://doi.org/10.1093/forestscience/38.1.95","url":null,"abstract":"Several morphological features were significantly related to the rooting response, and subsequent field performance as rooted cuttings, of shoots collected from hedged stool plants of an F1 hybrid between Pinus caribaea var. hondurensis and P. tecunumanii. Results indicate that it will be possible to manipulate rooting and field performance by shoot selection at the time of harvest of cuttings. The cutting which best meets the objective of maximum rooting without loss of field performance is the terminal segment from a shoot over 30 cm in length, with an actively growing juvenile bud, primary needles in excess of 25 mm, secondary needles present but less than 10 mm in length, and basal diameter over 2 mm. The use of second and third segments of shoots, where these have the appropriate features, would permit greater utilization of material with only a minor decrease in rooting. Primary needle length was the best morphological predictor of both rooting and field height growth. Significant positive genetic correlations suggest that within-family selection for primary needle length will involve selection for clones which root well and which display good height growth in the field, perhaps as a result of slower stool plant aging. For. Sci. 38(1):95-101.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"3 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140566116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-10DOI: 10.1093/forestscience/38.2.305
John G. Hof, Brian M. Kent, James B. Pickens
This paper treats a variety of approaches to account for random yield coefficients with known means and variances in renewable resource optimization models. General formulations are discussed first, followed by a forestry case example that demonstrates the formulations and resulting optimal solutions in a renewable resource application. Different approaches to approximating the normal cumulative density function are evaluated using simulation. For. Sci. 38(2):305-323.
{"title":"Chance Constraints and Chance Maximization with Random Yield Coefficients in Renewable Resource Optimization","authors":"John G. Hof, Brian M. Kent, James B. Pickens","doi":"10.1093/forestscience/38.2.305","DOIUrl":"https://doi.org/10.1093/forestscience/38.2.305","url":null,"abstract":"This paper treats a variety of approaches to account for random yield coefficients with known means and variances in renewable resource optimization models. General formulations are discussed first, followed by a forestry case example that demonstrates the formulations and resulting optimal solutions in a renewable resource application. Different approaches to approximating the normal cumulative density function are evaluated using simulation. For. Sci. 38(2):305-323.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"119 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140566235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-10DOI: 10.1093/forestscience/55.1.64
Bianca N.I. Eskelson, Hailemariam Temesgen, Tara M. Barrett
Information on current forest condition is essential to assess and characterize resources and to support resource management and policy decisions. The 1998 Farm Bill mandates the US Forest Service to conduct annual inventories to provide annual updates of each state's forest. In annual inventories, the sample size of 1 year (panel) is only a portion of the full sample and therefore the precision of the estimations for any given year is low. To achieve higher precision, the Forest Inventory and Analysis program uses a moving average (MA), which combines the data of multiple panels, as default estimator. The MA can result in biased estimates of current conditions and alternative methods are sought. Alternatives to MA have not yet been explored in the Pacific Northwest. Data from Oregon and Washington national forests were used to examine a weighted moving average (WMA) and three imputation approaches: most similar neighbor, gradient nearest neighbor, and randomForest (RF). Using the most recent measurements of the variables of interest as ancillary variables, RF provided almost unbiased estimates that were comparable to those of the MA and WMA estimators in terms of root mean square error.
有关当前森林状况的信息对于评估和描述资源特征以及支持资源管理和政策决策至关重要。1998 年的《农业法案》要求美国林业局进行年度清查，以提供各州森林的年度最新情况。在年度清查中，1 年（面板）的样本量仅为全部样本的一部分，因此任何给定年份的估算精度都很低。为了达到更高的精度，森林资源清查与分析程序使用移动平均值 (MA) 作为默认估算值，该值结合了多个面板的数据。移动平均法可能会导致对当前状况的估计出现偏差，因此需要寻求替代方法。西北太平洋地区尚未探索过移动平均法的替代方法。俄勒冈州和华盛顿州国家森林的数据被用来研究加权移动平均法（WMA）和三种估算方法：最相似邻近法、梯度最近邻近法和随机森林法（RF）。RF 使用相关变量的最新测量值作为辅助变量，提供了几乎无偏的估计值，其均方根误差与 MA 和 WMA 估计值相当。
{"title":"Estimating Current Forest Attributes from Paneled Inventory Data Using Plot-Level Imputation: A Study from the Pacific Northwest","authors":"Bianca N.I. Eskelson, Hailemariam Temesgen, Tara M. Barrett","doi":"10.1093/forestscience/55.1.64","DOIUrl":"https://doi.org/10.1093/forestscience/55.1.64","url":null,"abstract":"Information on current forest condition is essential to assess and characterize resources and to support resource management and policy decisions. The 1998 Farm Bill mandates the US Forest Service to conduct annual inventories to provide annual updates of each state's forest. In annual inventories, the sample size of 1 year (panel) is only a portion of the full sample and therefore the precision of the estimations for any given year is low. To achieve higher precision, the Forest Inventory and Analysis program uses a moving average (MA), which combines the data of multiple panels, as default estimator. The MA can result in biased estimates of current conditions and alternative methods are sought. Alternatives to MA have not yet been explored in the Pacific Northwest. Data from Oregon and Washington national forests were used to examine a weighted moving average (WMA) and three imputation approaches: most similar neighbor, gradient nearest neighbor, and randomForest (RF). Using the most recent measurements of the variables of interest as ancillary variables, RF provided almost unbiased estimates that were comparable to those of the MA and WMA estimators in terms of root mean square error.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"7 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140566639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-10DOI: 10.1093/forestscience/36.2.358
Kurt D. Pennell, H. Lee Allen, William A. Jackson
Excised loblolly pine roots were exposed to a 32p-labelled solution for 20 minutes to measure their capacity for P uptake. On five dates from March 1985 to March 1986, root samples were collected from 14-year-old loblolly pine which had received 101 kg P · ha-1 and 0 kg P · ha-1 when they were planted. Phosphorus uptake by roots of nonfertilized loblolly pine (1.10 μmol P · g-1 · hr-1) was significantly greater than that by roots of fertilized loblolly pine (0.72 μmol P · g-1 · hr-1) when sampled between June and October, but no difference was detected when sampled in March. Phosphorus uptake was decreased by approximately 50% at 7°C compared to 25°C, and in the presence of metabolic inhibitors. Phosphorus concentrations, measured after the bioassay, of roots from fertilized trees (0.93 g P · kg-1) were significantly greater than those of roots from nonfertilized trees (0.45 g P · kg-1) on all five sampling dates. Capacity for root P uptake did not have an advantage over root or foliar P concentrations as an indicator of P stress, and does not appear to be a practical diagnostic tool for semimature loblolly pine. For. Sci. 36(2):358-366.
将切除的小叶松根暴露在 32p 标记溶液中 20 分钟，以测量其吸收 P 的能力。在 1985 年 3 月至 1986 年 3 月的五个日期，从 14 年树龄的小叶松根部采集了样本，这些小叶松在种植时分别吸收了 101 千克 P - ha-1 和 0 千克 P - ha-1。在 6 月至 10 月采样时，未施肥小叶女贞的根系对磷的吸收量（1.10 μmol P - g-1 - hr-1）明显高于施肥小叶女贞的根系对磷的吸收量（0.72 μmol P - g-1 - hr-1），但在 3 月采样时未发现差异。与 25 摄氏度相比，在 7 摄氏度和存在代谢抑制剂的情况下，磷的吸收量减少了约 50%。在所有五个取样日期，生物测定后测量的施肥树木根部的磷浓度（0.93 g P - kg-1）都明显高于未施肥树木根部的磷浓度（0.45 g P - kg-1）。根系吸收 P 的能力作为 P 压力的指标，与根系或叶片 P 浓度相比没有优势，似乎不是半成熟小叶松的实用诊断工具。对于小叶松来说，这似乎并不是一个实用的诊断工具。36(2):358-366.
{"title":"Phosphorus Uptake Capacity of 14-Year-Old Loblolly Pine as Indicated by a 32P Root Bioassay","authors":"Kurt D. Pennell, H. Lee Allen, William A. Jackson","doi":"10.1093/forestscience/36.2.358","DOIUrl":"https://doi.org/10.1093/forestscience/36.2.358","url":null,"abstract":"Excised loblolly pine roots were exposed to a 32p-labelled solution for 20 minutes to measure their capacity for P uptake. On five dates from March 1985 to March 1986, root samples were collected from 14-year-old loblolly pine which had received 101 kg P · ha-1 and 0 kg P · ha-1 when they were planted. Phosphorus uptake by roots of nonfertilized loblolly pine (1.10 μmol P · g-1 · hr-1) was significantly greater than that by roots of fertilized loblolly pine (0.72 μmol P · g-1 · hr-1) when sampled between June and October, but no difference was detected when sampled in March. Phosphorus uptake was decreased by approximately 50% at 7°C compared to 25°C, and in the presence of metabolic inhibitors. Phosphorus concentrations, measured after the bioassay, of roots from fertilized trees (0.93 g P · kg-1) were significantly greater than those of roots from nonfertilized trees (0.45 g P · kg-1) on all five sampling dates. Capacity for root P uptake did not have an advantage over root or foliar P concentrations as an indicator of P stress, and does not appear to be a practical diagnostic tool for semimature loblolly pine. For. Sci. 36(2):358-366.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"8 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140566052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-10DOI: 10.1093/forestscience/54.6.647
Dirk Pflugmacher, Warren Cohen, Robert Kennedy, Michael Lefsky
Accurate estimates of forest aboveground biomass are needed to reduce uncertainties in global and regional terrestrial carbon fluxes. In this study we investigated the utility of the Geoscience Laser Altimeter System (GLAS) onboard the Ice, Cloud and land Elevation Satellite for large-scale biomass inventories. GLAS is the first spaceborne lidar sensor that will provide global estimates of forest height. We compared accuracy and regional variability of GLAS height estimates with data from the US Forest Service Inventory and Analysis (FIA) program and found that current GLAS algorithms provided generally accurate estimates of height. GLAS heights were on average 2–3 m lower than FIA estimates. To translate GLAS-estimated heights into forest biomass will require general allometric equations. Analysis of the regional variability of forest height-biomass relationships using FIA field data indicates that general nonspecies specific equations are applicable without a significant loss of prediction accuracy. We developed biomass models from FIA data and applied them to the GLAS-estimated heights. Regional estimates of forest biomass from GLAS differed between 39.7 and 58.2 Mg ha−1 compared with FIA.
为了减少全球和区域陆地碳通量的不确定性，需要对森林地上生物量进行精确估算。在这项研究中，我们调查了冰云陆地高程卫星上的地球科学激光测高系统（GLAS）在大规模生物量清查中的实用性。GLAS 是首个可提供全球森林高度估计值的星载激光雷达传感器。我们将 GLAS 高度估算的准确性和区域变异性与美国林务局清查和分析（FIA）计划的数据进行了比较，发现目前的 GLAS 算法提供的高度估算基本准确。GLAS 估算的高度比 FIA 估算的高度平均低 2-3 米。要将 GLAS 估算的高度转化为森林生物量，需要使用一般的计量方程。利用森林资源评估实地数据对森林高度-生物量关系的区域变异性进行的分析表明，一般的非物种特异性方程是适用的，而且不会明显降低预测精度。我们根据 FIA 数据开发了生物量模型，并将其应用于 GLAS 估算的高度。与 FIA 相比，GLAS 对森林生物量的区域估算值相差 39.7 至 58.2 兆克/公顷。
{"title":"Regional Applicability of Forest Height and Aboveground Biomass Models for the Geoscience Laser Altimeter System","authors":"Dirk Pflugmacher, Warren Cohen, Robert Kennedy, Michael Lefsky","doi":"10.1093/forestscience/54.6.647","DOIUrl":"https://doi.org/10.1093/forestscience/54.6.647","url":null,"abstract":"Accurate estimates of forest aboveground biomass are needed to reduce uncertainties in global and regional terrestrial carbon fluxes. In this study we investigated the utility of the Geoscience Laser Altimeter System (GLAS) onboard the Ice, Cloud and land Elevation Satellite for large-scale biomass inventories. GLAS is the first spaceborne lidar sensor that will provide global estimates of forest height. We compared accuracy and regional variability of GLAS height estimates with data from the US Forest Service Inventory and Analysis (FIA) program and found that current GLAS algorithms provided generally accurate estimates of height. GLAS heights were on average 2–3 m lower than FIA estimates. To translate GLAS-estimated heights into forest biomass will require general allometric equations. Analysis of the regional variability of forest height-biomass relationships using FIA field data indicates that general nonspecies specific equations are applicable without a significant loss of prediction accuracy. We developed biomass models from FIA data and applied them to the GLAS-estimated heights. Regional estimates of forest biomass from GLAS differed between 39.7 and 58.2 Mg ha−1 compared with FIA.","PeriodicalId":12749,"journal":{"name":"Forest Science","volume":"18 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140566081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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