Forest Science最新文献

{"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}

{"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}

{"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}

{"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}

{"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}

{"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}

{"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}

{"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}

{"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}

{"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}