Author: Crystal Lynn Raymond Publisher: ISBN: Category : Conifers Languages : en Pages : 36
Book Description
Accurate estimates of foliar biomass (FB) are important for quantifying carbon storage in forest ecosystems, but FB is not always reported in regional or national inventories. Foliar biomass also drives key ecological processes in ecosystem models. Published algorithms for estimating FB in conifer species of the Pacific Northwest can yield signifi cantly different results, but have not been rigorously compared for species other than Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). We compared five algorithms for estimating FB for seven common coniferous species in the Pacific Northwest. Algorithms based on diameter at breast height (DBH), or on DBH and height, consistently yield higher estimates of FB than algorithms based on sapwood area. At the tree level, differences between algorithms increased with increasing DBH for all species, but their order and magnitude differed by species. At the stand level, differences among algorithms were muted by the mix of species and diameter classes that contributed to total FB of stands of different seral stages and species composition. Significant differences among estimates of FB from different algorithms show the need for consistent methods for estimating FB for carbon accounting, tests of the sensitivity of ecosystem models to these differences, and more field observations to compare algorithms.
Author: Crystal Lynn Raymond Publisher: ISBN: Category : Conifers Languages : en Pages : 23
Book Description
Accurate estimates of foliar biomass (FB) are important for quantifying carbon storage in forest ecosystems, but FB is not always reported in regional or national inventories. Foliar biomass also drives key ecological processes in ecosystem models. Published algorithms for estimating FB in conifer species of the Pacific Northwest can yield signifi cantly different results, but have not been rigorously compared for species other than Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). We compared five algorithms for estimating FB for seven common coniferous species in the Pacific Northwest. Algorithms based on diameter at breast height (DBH), or on DBH and height, consistently yield higher estimates of FB than algorithms based on sapwood area. At the tree level, differences between algorithms increased with increasing DBH for all species, but their order and magnitude differed by species. At the stand level, differences among algorithms were muted by the mix of species and diameter classes that contributed to total FB of stands of different seral stages and species composition. Significant differences among estimates of FB from different algorithms show the need for consistent methods for estimating FB for carbon accounting, tests of the sensitivity of ecosystem models to these differences, and more field observations to compare algorithms.
Author: Crystal Lynn Raymond Publisher: ISBN: Category : Conifers Languages : en Pages : 23
Book Description
Accurate estimates of foliar biomass (FB) are important for quantifying carbon storage in forest ecosystems, but FB is not always reported in regional or national inventories. Foliar biomass also drives key ecological processes in ecosystem models. Published algorithms for estimating FB in conifer species of the Pacific Northwest can yield signifi cantly different results, but have not been rigorously compared for species other than Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). We compared five algorithms for estimating FB for seven common coniferous species in the Pacific Northwest. Algorithms based on diameter at breast height (DBH), or on DBH and height, consistently yield higher estimates of FB than algorithms based on sapwood area. At the tree level, differences between algorithms increased with increasing DBH for all species, but their order and magnitude differed by species. At the stand level, differences among algorithms were muted by the mix of species and diameter classes that contributed to total FB of stands of different seral stages and species composition. Significant differences among estimates of FB from different algorithms show the need for consistent methods for estimating FB for carbon accounting, tests of the sensitivity of ecosystem models to these differences, and more field observations to compare algorithms.
Author: Warren D. Devine Publisher: ISBN: Category : Douglas fir Languages : en Pages : 29
Book Description
We sampled trees grown with and without competing vegetation control in an 11-year-old Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) plantation on a highly productive site in southwestern Washington to create diameter- based allometric equations for estimating individual-tree bole, branch, foliar, and total aboveground biomass. We used these equations to estimate per-hectare aboveground biomass, nitrogen (N), and carbon (C) content, and compared these results to (1) estimates based on biomass equations published in other studies, and (2) estimates made using the mean-tree method rather than allometric equations. Component and total-tree biomass equations were not influenced by the presence of vegetation control, although per-hectare biomass, C, and N estimates were greater where vegetation control was applied. Our biomass estimates differed from estimates using previously published biomass equations by as much as 23 percent. When using the mean-tree biomass estimation approach, we found that incorporating a previously published biomass equation improved accuracy of the mean-tree diameter calculation.
Author: Joe H. Scott Publisher: ISBN: Category : Fire risk assessment Languages : en Pages : 68
Book Description
Fire managers are increasingly concerned about the threat of crown fires, yet only now are quantitative methods for assessing crown fire hazard being developed. Links among existing mathematical models of fire behavior are used to develop two indices of crown fire hazard-the Torching Index and Crowning Index. These indices can be used to ordinate different forest stands by their relative susceptibility to crown fire and to compare the effectiveness of crown fire mitigation treatments. The coupled model was used to simulate the wide range of fire behavior possible in a forest stand, from a low-intensity surface fire to a high-intensity active crown fire, for the purpose of comparing potential fire behavior. The hazard indices and behavior simulations incorporate the effects of surface fuel characteristics, dead and live fuel moistures (surface and crown), slope steepness, canopy base height, canopy bulk density, and wind reduction by the canopy. Example simulations are for western Montana Pinus ponderosa and Pinus contorta stands. Although some of the models presented here have had limited testing or restricted geographic applicability, the concepts will apply to models for other regions and new models with greater geographic applicability.
Author: Crystal Lynn Raymond
Author: Crystal Lynn Raymond
Author: Crystal Lynn Raymond
Author: Donald McKenzie
Author: 
Author: Warren D. Devine
Author: Sally J. Campbell
Author: 
Author: E. Gregory McPherson
Author: Joe H. Scott