The volume increment of individual trees is often inferred from a volume or taper equation and predicted or observed diameter and height increments. Prediction errors can be compounded with this type of approach because of the array of equations used and differences in their accuracy. The consequences of several alternative approaches for indirectly or directly estimating individual tree volume increment were examined using an extensive stem analysis data set of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) in southwest Oregon. The data were used to construct new stem volume, taper, and volume increment equations, which were then used to compare predicted and observed 5-year volume increments. The results of this analysis suggest that the indirect prediction of volume increment is sensitive to both the approach used for estimating stem volume and the use of actual versus predicted diameter and height increment, especially diameter increment. In addition, using the indirect method of volume and taper equations was found to have a slightly lower level of accuracy in predicting stem volume increment than the direct method. It was found that the use of local calibration procedures could help to mitigate possible problems with the bias incurred by using predicted rather than actual diameter increment.
{"title":"Evaluation of alternative approaches for predicting individual tree volume increment.","authors":"D. Hann, A. Weiskittel","doi":"10.1093/WJAF/25.3.120","DOIUrl":"https://doi.org/10.1093/WJAF/25.3.120","url":null,"abstract":"The volume increment of individual trees is often inferred from a volume or taper equation and predicted or observed diameter and height increments. Prediction errors can be compounded with this type of approach because of the array of equations used and differences in their accuracy. The consequences of several alternative approaches for indirectly or directly estimating individual tree volume increment were examined using an extensive stem analysis data set of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) in southwest Oregon. The data were used to construct new stem volume, taper, and volume increment equations, which were then used to compare predicted and observed 5-year volume increments. The results of this analysis suggest that the indirect prediction of volume increment is sensitive to both the approach used for estimating stem volume and the use of actual versus predicted diameter and height increment, especially diameter increment. In addition, using the indirect method of volume and taper equations was found to have a slightly lower level of accuracy in predicting stem volume increment than the direct method. It was found that the use of local calibration procedures could help to mitigate possible problems with the bias incurred by using predicted rather than actual diameter increment.","PeriodicalId":51220,"journal":{"name":"Western Journal of Applied Forestry","volume":"25 1","pages":"120-126"},"PeriodicalIF":0.0,"publicationDate":"2010-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/WJAF/25.3.120","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61109024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Three sets of linear models were developed to predict several forest attributes, using stand-level and single-tree remote sensing (STRS) light detection and ranging (LiDAR) metrics as predictor variables. The first used only area-level metrics (ALM) associated with first-return height distribution, percentage of cover, and canopy transparency. The second alternative included metrics of first-return LiDAR intensity. The third alternative used area-level variables derived from STRS LiDAR metrics. The ALM model for Lorey’s height did not change with inclusion of intensity and yielded the best results in terms of both model fit (adjusted R 2 0.93) and cross-validated relative root mean squared error (RRMSE 8.1%). The ALM model for density (stems per hectare) had the poorest precision initially (RRMSE 39.3%), but it improved dramatically (RRMSE 27.2%) when intensity metrics were included. The resulting RRMSE values of the ALM models excluding intensity for basal area, quadratic mean diameter, cubic stem volume, and average crown width were 20.7, 19.9, 30.7, and 17.1%, respectively. The STRS model for Lorey’s height showed a 3% improvement in RRMSE over the ALM models. The STRS basal area and density models significantly underperformed compared with the ALM models, with RRMSE values of 31.6 and 47.2%, respectively. The performance of STRS models for crown width, volume, and quadratic mean diameter was comparable to that of the ALM models.
{"title":"Relating Forest Attributes with Area- and Tree-Based Light Detection and Ranging Metrics for Western Oregon","authors":"Michael E. Goerndt, V. Monleon, H. Temesgen","doi":"10.1093/WJAF/25.3.105","DOIUrl":"https://doi.org/10.1093/WJAF/25.3.105","url":null,"abstract":"Three sets of linear models were developed to predict several forest attributes, using stand-level and single-tree remote sensing (STRS) light detection and ranging (LiDAR) metrics as predictor variables. The first used only area-level metrics (ALM) associated with first-return height distribution, percentage of cover, and canopy transparency. The second alternative included metrics of first-return LiDAR intensity. The third alternative used area-level variables derived from STRS LiDAR metrics. The ALM model for Lorey’s height did not change with inclusion of intensity and yielded the best results in terms of both model fit (adjusted R 2 0.93) and cross-validated relative root mean squared error (RRMSE 8.1%). The ALM model for density (stems per hectare) had the poorest precision initially (RRMSE 39.3%), but it improved dramatically (RRMSE 27.2%) when intensity metrics were included. The resulting RRMSE values of the ALM models excluding intensity for basal area, quadratic mean diameter, cubic stem volume, and average crown width were 20.7, 19.9, 30.7, and 17.1%, respectively. The STRS model for Lorey’s height showed a 3% improvement in RRMSE over the ALM models. The STRS basal area and density models significantly underperformed compared with the ALM models, with RRMSE values of 31.6 and 47.2%, respectively. The performance of STRS models for crown width, volume, and quadratic mean diameter was comparable to that of the ALM models.","PeriodicalId":51220,"journal":{"name":"Western Journal of Applied Forestry","volume":"25 1","pages":"105-111"},"PeriodicalIF":0.0,"publicationDate":"2010-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/WJAF/25.3.105","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61109001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The effects of forestry site preparation on mountain beaver demographics and associated damage to tree seedlings.","authors":"Wendy M. Arjo","doi":"10.1093/WJAF/25.3.127","DOIUrl":"https://doi.org/10.1093/WJAF/25.3.127","url":null,"abstract":"","PeriodicalId":51220,"journal":{"name":"Western Journal of Applied Forestry","volume":"25 1","pages":"127-135"},"PeriodicalIF":0.0,"publicationDate":"2010-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/WJAF/25.3.127","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61109043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
however, can vary by Armillaria clone, site and soil characteristics, disturbance history, and plant association (McDonald et al.1987, Curran et al. 2007). Single genets (clones) of A. ostoyae (“the humongous fungus”) have been estimated to be 2,400 ac in size and 2,200 years old in northeast Oregon (Schmitt and Tatum 2008), and wildfires may have little effect in reducing populations of subterranean root pathogens such as A. ostoyae (Ferguson et al. 2003, Fields 2003). A name change to Armillaria solidipes has been recently proposed for A. ostoyae (Burdsall and Volk 2008). Besides tree mortality, Armillaria infections may cause crown dieback, resinous-root lesions, treegrowth reductions, lower-stem deformations, stand-structural changes, and down-wood accumulations (Bloomberg and Morrison 1989, Reaves et al. 1993, Cruickshank et al. 1997, 2009, Mallett and Volney 1999, Cruickshank 2002, Fields 2003, Omdal et al. 2004). The association between tree wounding and Armillaria infection is not well known. Severe wounding of roots or stems could exacerbate existing root infections and possibly result in tree mortality. Armillaria root disease has been associated with stressed trees resulting from soil disturbance, high stand densities, drought, or other pest attack (Wargo and Shaw 1985, Hadfield et al. 1986, Williams et al. 1986, Shaw and Kile 1991). In severely infected forests in the Pacific Northwest, tree mortality caused by A. ostoyae has been estimated at 25 ft/ac per year on 1,500 ac in south-central Washington (Shaw et al. 1976), 50 ft/ac per year on 575 ac in south-central Oregon (Filip 1977), and 30 ft/ac per year on 2,500 ac in central Oregon (Filip and Goheen 1982). Dead root systems may be completely colonized by Armillaria 1 to 5 years after tree death or harvesting, depending on Armillaria genet, tree species, size of the root system, number of infected-root lesions, and extent of root colonization by insects or other fungi. Because Armillaria can persist for millennia on infected mixedconifer sites and therefore eradication is futile, we tested the hypothesis that silvicultural treatments can reduce growth loss and mortality caused by Armillaria and reestablish Armillaria-tolerant tree species. The study was conducted in an uneven-aged mixed-conifer forest (but predominantly true fir). The objectives of our study were to determine whether significant differences occur between treated and untreated areas in the amount of 10-year leave-tree dbh-growth loss and mortality with shelterwood harvesting or group-selection harvesting, and to evaluate the frequency of mortality among six A. ostoyae“tolerant” species that were regenerated in the shelterwood and group-selection stands: ponderosa pine, lodgepole pine (Pinus contorta), sugar pine (Pinus lambertiana), coastal Douglas-fir, western larch, and incense-cedar.
然而，可能因蜜环菌无性系、地点和土壤特征、干扰历史和植物关联而异(McDonald et al.1987, Curran et al. 2007)。据估计，单基因(克隆)的A. ostoyae(“巨大的真菌”)在俄勒冈州东北部的规模为2,400 ac，已有2,200年的历史(Schmitt和Tatum 2008)，野火可能对减少A. ostoyae等地下根系病原体的种群影响不大(Ferguson et al. 2003, Fields 2003)。最近有人提议将A. ostoyae的名称改为蜜环菌固化菌(Burdsall and Volk 2008)。除了树木死亡外，蜜环菌感染还可能导致树冠枯死、树脂根病变、树木生长减少、下部茎变形、林分结构变化和木材积聚(Bloomberg and Morrison 1989, Reaves et al. 1993, Cruickshank et al. 1997, 2009, Mallett and Volney 1999, Cruickshank 2002, Fields 2003, Omdal et al. 2004)。树木损伤与蜜环菌感染之间的关系尚不清楚。根或茎的严重损伤会加剧现有的根感染，并可能导致树木死亡。蜜环菌根病与土壤扰动、林分密度高、干旱或其他虫害侵袭造成的胁迫树木有关(Wargo和Shaw 1985, Hadfield等人1986,Williams等人1986,Shaw和Kile 1991)。在太平洋西北地区严重感染的森林中，据估计，在华盛顿州中南部1500ac的树木死亡率为25英尺/平方米/年(Shaw et al. 1976)，在俄勒冈州中南部575ac的树木死亡率为50英尺/平方米/年(Filip 1977)，在俄勒冈州中部2500 ac的树木死亡率为30英尺/平方米/年(Filip and Goheen 1982)。在树木死亡或收获后1至5年，死亡的根系可能完全被蜜环菌定殖，这取决于蜜环菌属、树种、根系大小、受感染的根系病变数量以及昆虫或其他真菌在根系定殖的程度。由于蜜环菌可以在受感染的混合针叶树上存活数千年，因此根除是徒劳的，我们测试了造林处理可以减少由蜜环菌引起的生长损失和死亡率，并重建耐蜜环菌的树种的假设。该研究是在一个年龄不均匀的混合针叶林(但主要是真冷杉)进行的。本研究的目的是确定阔叶林采伐和群选采伐在阔叶树10年生长量和死亡率方面是否存在显著差异，并评估在阔叶林和群选林分再生的6种“耐受”树种的死亡率。黄松、黑松、糖松、沿海道格拉斯冷杉、西部落叶松和香雪松。
{"title":"Armillaria root disease-caused tree mortality following silvicultural treatments (shelterwood or group selection) in an Oregon mixed-conifer forest: insights from a 10-year case study.","authors":"G. Filip, H. Maffei, K. Chadwick, T. Max","doi":"10.1093/WJAF/25.3.136","DOIUrl":"https://doi.org/10.1093/WJAF/25.3.136","url":null,"abstract":"however, can vary by Armillaria clone, site and soil characteristics, disturbance history, and plant association (McDonald et al.1987, Curran et al. 2007). Single genets (clones) of A. ostoyae (“the humongous fungus”) have been estimated to be 2,400 ac in size and 2,200 years old in northeast Oregon (Schmitt and Tatum 2008), and wildfires may have little effect in reducing populations of subterranean root pathogens such as A. ostoyae (Ferguson et al. 2003, Fields 2003). A name change to Armillaria solidipes has been recently proposed for A. ostoyae (Burdsall and Volk 2008). Besides tree mortality, Armillaria infections may cause crown dieback, resinous-root lesions, treegrowth reductions, lower-stem deformations, stand-structural changes, and down-wood accumulations (Bloomberg and Morrison 1989, Reaves et al. 1993, Cruickshank et al. 1997, 2009, Mallett and Volney 1999, Cruickshank 2002, Fields 2003, Omdal et al. 2004). The association between tree wounding and Armillaria infection is not well known. Severe wounding of roots or stems could exacerbate existing root infections and possibly result in tree mortality. Armillaria root disease has been associated with stressed trees resulting from soil disturbance, high stand densities, drought, or other pest attack (Wargo and Shaw 1985, Hadfield et al. 1986, Williams et al. 1986, Shaw and Kile 1991). In severely infected forests in the Pacific Northwest, tree mortality caused by A. ostoyae has been estimated at 25 ft/ac per year on 1,500 ac in south-central Washington (Shaw et al. 1976), 50 ft/ac per year on 575 ac in south-central Oregon (Filip 1977), and 30 ft/ac per year on 2,500 ac in central Oregon (Filip and Goheen 1982). Dead root systems may be completely colonized by Armillaria 1 to 5 years after tree death or harvesting, depending on Armillaria genet, tree species, size of the root system, number of infected-root lesions, and extent of root colonization by insects or other fungi. Because Armillaria can persist for millennia on infected mixedconifer sites and therefore eradication is futile, we tested the hypothesis that silvicultural treatments can reduce growth loss and mortality caused by Armillaria and reestablish Armillaria-tolerant tree species. The study was conducted in an uneven-aged mixed-conifer forest (but predominantly true fir). The objectives of our study were to determine whether significant differences occur between treated and untreated areas in the amount of 10-year leave-tree dbh-growth loss and mortality with shelterwood harvesting or group-selection harvesting, and to evaluate the frequency of mortality among six A. ostoyae“tolerant” species that were regenerated in the shelterwood and group-selection stands: ponderosa pine, lodgepole pine (Pinus contorta), sugar pine (Pinus lambertiana), coastal Douglas-fir, western larch, and incense-cedar.","PeriodicalId":51220,"journal":{"name":"Western Journal of Applied Forestry","volume":"25 1","pages":"136-143"},"PeriodicalIF":0.0,"publicationDate":"2010-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/WJAF/25.3.136","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61109050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Allometric equation development, biomass, and aboveground productivity in ponderosa pine forests, Black Hills, Wyoming.","authors":"D. Tinker, Gail K. Stakes, R. Arcano","doi":"10.1093/WJAF/25.3.112","DOIUrl":"https://doi.org/10.1093/WJAF/25.3.112","url":null,"abstract":"","PeriodicalId":51220,"journal":{"name":"Western Journal of Applied Forestry","volume":"25 1","pages":"112-119"},"PeriodicalIF":0.0,"publicationDate":"2010-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/WJAF/25.3.112","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61109010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Sessions, Jeff Wimer, Forrest Costales, M. Wing
{"title":"Engineering considerations in road assessment for biomass operations in steep terrain.","authors":"J. Sessions, Jeff Wimer, Forrest Costales, M. Wing","doi":"10.1093/WJAF/25.3.144","DOIUrl":"https://doi.org/10.1093/WJAF/25.3.144","url":null,"abstract":"","PeriodicalId":51220,"journal":{"name":"Western Journal of Applied Forestry","volume":"25 1","pages":"144-153"},"PeriodicalIF":0.0,"publicationDate":"2010-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/WJAF/25.3.144","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61109063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In late summer 2000 the Jasper Fire burned approximately 34,000 ha of ponderosa pine forest in the Black Hills of South Dakota. Although regarded as a catastrophic event, the Jasper Fire left a mosaic of fire severity across the landscape, with live trees present in areas burned under low and moderate fire severity. In October 2005, we cored 96 trees from unburned, low-severity, and moderate-severity stands and assessed whether tree growth differed among fire severity classes during the 5 years postfire. We observed no differences in basal area increment (BAI) 10 years prefire among fire severities with BAI averaging 9.6 cm2 per year. Despite severe drought conditions, BAI in moderate severity sites 2 years postfire was 58% greater than in unburned and low-severity stands. Although significant, this growth increase was short-lived. Three, 4, and 5 years postfire, no differences in growth among unburned, low-severity, and moderate-severity sites were detected, as BAI averaged 8.3, 7.5, and 7.0 cm2, respectively. The lack of a consistent and prolonged growth response suggests that the Jasper Fire did not result in any short-term changes in growth patterns. Data extending beyond 5 years postfire are required to infer potential long-term changes in tree growth and productivity.
{"title":"Growth response of Pinus ponderosa following a mixed-severity wildfire in the Black Hills, South Dakota.","authors":"T. Keyser, F. Smith, W. Shepperd","doi":"10.1093/WJAF/25.2.49","DOIUrl":"https://doi.org/10.1093/WJAF/25.2.49","url":null,"abstract":"In late summer 2000 the Jasper Fire burned approximately 34,000 ha of ponderosa pine forest in the Black Hills of South Dakota. Although regarded as a catastrophic event, the Jasper Fire left a mosaic of fire severity across the landscape, with live trees present in areas burned under low and moderate fire severity. In October 2005, we cored 96 trees from unburned, low-severity, and moderate-severity stands and assessed whether tree growth differed among fire severity classes during the 5 years postfire. We observed no differences in basal area increment (BAI) 10 years prefire among fire severities with BAI averaging 9.6 cm2 per year. Despite severe drought conditions, BAI in moderate severity sites 2 years postfire was 58% greater than in unburned and low-severity stands. Although significant, this growth increase was short-lived. Three, 4, and 5 years postfire, no differences in growth among unburned, low-severity, and moderate-severity sites were detected, as BAI averaged 8.3, 7.5, and 7.0 cm2, respectively. The lack of a consistent and prolonged growth response suggests that the Jasper Fire did not result in any short-term changes in growth patterns. Data extending beyond 5 years postfire are required to infer potential long-term changes in tree growth and productivity.","PeriodicalId":51220,"journal":{"name":"Western Journal of Applied Forestry","volume":"25 1","pages":"49-54"},"PeriodicalIF":0.0,"publicationDate":"2010-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/WJAF/25.2.49","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61108351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Noble fir (Abies procera Rehder) bough harvest has been part of the nontimber forest products industry in the Pacific Northwest for decades. The boughs are used for seasonal decorations and command a higher price than most other decorative bough species. However, noble fir boughs that are harvested in the region have been merely a byproduct of noble fir plantations managed for timber products. This article presents the results of a study assessing the financial desirability of managing noble fir plantations in the southern Cascade Mountains of Washington State for the production of both timber and bough products. The Landscape Management System software program was used to simulate the growth of noble fir in four different plant associations on the Gifford Pinchot National Forest. Data from recently established noble fir plantations were used in the simulations. Harvestable bough weights were estimated using a previously published noble fir bough weight model. Comparisons of estimated harvest volumes for sawlogs and noble fir boughs showed positive present net worth (PNW) values for each stand under a combined timber production and bough harvest scenario and negative PNW values for each stand with a timber production management scenario only. Bough harvest is compatible with other land use activities, and the harvest revenue can cover stand establishment and precommercial thinning costs.
{"title":"Returns from the Management of Noble Fir Stands for Bough Production and Sawtimber","authors":"K. Blatner, P. Cohn, R. Fight","doi":"10.1093/WJAF/25.2.68","DOIUrl":"https://doi.org/10.1093/WJAF/25.2.68","url":null,"abstract":"Noble fir (Abies procera Rehder) bough harvest has been part of the nontimber forest products industry in the Pacific Northwest for decades. The boughs are used for seasonal decorations and command a higher price than most other decorative bough species. However, noble fir boughs that are harvested in the region have been merely a byproduct of noble fir plantations managed for timber products. This article presents the results of a study assessing the financial desirability of managing noble fir plantations in the southern Cascade Mountains of Washington State for the production of both timber and bough products. The Landscape Management System software program was used to simulate the growth of noble fir in four different plant associations on the Gifford Pinchot National Forest. Data from recently established noble fir plantations were used in the simulations. Harvestable bough weights were estimated using a previously published noble fir bough weight model. Comparisons of estimated harvest volumes for sawlogs and noble fir boughs showed positive present net worth (PNW) values for each stand under a combined timber production and bough harvest scenario and negative PNW values for each stand with a timber production management scenario only. Bough harvest is compatible with other land use activities, and the harvest revenue can cover stand establishment and precommercial thinning costs.","PeriodicalId":51220,"journal":{"name":"Western Journal of Applied Forestry","volume":"25 1","pages":"68-72"},"PeriodicalIF":0.0,"publicationDate":"2010-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/WJAF/25.2.68","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61108945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Growth models for coast Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco) are generally based on measurements of stands that are genetically unimproved (or woods-run); therefore, they cannot be expected to accurately project the development of stands that originate from improved seedlots. In this report, we demonstrate how early expected gain and genetic-gain multipliers can be incorporated into growth projection, and we also summarize projected volume gains and other aspects of stand development under different levels of genetic gain, site productivity, and initial planting density. Representative tree lists that included three levels of productivity (site index = 100, 125, and 150 ft; base = 50 years) and three initial planting densities (302, 435, and 602 trees/ac) were projected from ages 10 to 60 years under three scenarios using two regional growth models (Stand Management Cooperative version of ORGANON and the Pacific Northwest variant of the Forest Vegetation Simulator). The two models projected similar percentage volume gains for improved seedlots. Seedlots with a genetic worth (GW) of 5% for height and diameter growth were projected to have volume gains of 3.3-5.8% over woods-run stands at 40 years and 2.1-3.2% at 60 years. Volume gains were projected to approximately double when GW was increased from 5 to 10%.
海岸道格拉斯冷杉(pseudosuga menziesii var. menziesii)生长模式[b]。[Franco])通常基于对未经基因改良(或林木经营)的林分的测量;因此，不能指望它们准确地预测来自改良苗区的林分的发展。在本报告中，我们展示了如何将早期预期增益和遗传增益乘数纳入生长预测，并总结了在不同遗传增益、立地生产力和初始种植密度水平下的预估体积增益和林分发育的其他方面。代表性的采油树列表包括三个生产力水平(站点指数= 100、125和150英尺;使用两种区域生长模式(ORGANON的林分管理合作版和太平洋西北版森林植被模拟器)，在3种情景下预测了10 ~ 60年的3种初始种植密度(302、435和602棵/ac)。这两种模型预测改良苗区的产量增长百分比相似。高度和直径生长遗传价值为5%的苗木，预计在40年和60年期间比林分增加3.3-5.8%和2.1-3.2%。当GW从5%增加到10%时，预计容量收益将增加约一倍。
{"title":"Incorporation of genetic gain into growth projections of Douglas-Fir using ORGANON and the Forest Vegetation Simulator","authors":"P. Gould, D. Marshall","doi":"10.1093/WJAF/25.2.55","DOIUrl":"https://doi.org/10.1093/WJAF/25.2.55","url":null,"abstract":"Growth models for coast Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco) are generally based on measurements of stands that are genetically unimproved (or woods-run); therefore, they cannot be expected to accurately project the development of stands that originate from improved seedlots. In this report, we demonstrate how early expected gain and genetic-gain multipliers can be incorporated into growth projection, and we also summarize projected volume gains and other aspects of stand development under different levels of genetic gain, site productivity, and initial planting density. Representative tree lists that included three levels of productivity (site index = 100, 125, and 150 ft; base = 50 years) and three initial planting densities (302, 435, and 602 trees/ac) were projected from ages 10 to 60 years under three scenarios using two regional growth models (Stand Management Cooperative version of ORGANON and the Pacific Northwest variant of the Forest Vegetation Simulator). The two models projected similar percentage volume gains for improved seedlots. Seedlots with a genetic worth (GW) of 5% for height and diameter growth were projected to have volume gains of 3.3-5.8% over woods-run stands at 40 years and 2.1-3.2% at 60 years. Volume gains were projected to approximately double when GW was increased from 5 to 10%.","PeriodicalId":51220,"journal":{"name":"Western Journal of Applied Forestry","volume":"25 1","pages":"55-61"},"PeriodicalIF":0.0,"publicationDate":"2010-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/WJAF/25.2.55","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61108367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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