The northern forests of are main1y inc1uded two northern forest regions in theNortheast and the Northwest of China.The first region can be subdivided into the boreal conifer and deciduous forest district of the Great ...The northern forests of are main1y inc1uded two northern forest regions in theNortheast and the Northwest of China.The first region can be subdivided into the boreal conifer and deciduous forest district of the Great Xing’an Mountains and the conifer and deciduous forest district ofLesser Xing’an Mountains;thc second one can be subdivbided into the Northern Montane forest dis-trict of Tianshan Mountains and the Northern Montane coniferous forcst district.It gives a com-pregesive description for the environmental characters,distribution of vegetation and main treespecies of the four distriets.展开更多
In the northeastern United States, whole-tree harvesting is widely used to supply fuel to biomass energy facilities, but questions remain regarding its long-term sustainability. We have previously reported findings in...In the northeastern United States, whole-tree harvesting is widely used to supply fuel to biomass energy facilities, but questions remain regarding its long-term sustainability. We have previously reported findings indicating no short-term decrease in forest productivity in whole-tree harvested sites when compared with similar conventionally (stem-only) harvested sites. Here we present additional results of the same study, but focus on the effect harvest treatment has on the species composition of the regenerating forest. Within northern hardwood forests in central New Hampshire and western Maine, regeneration surveys were conducted on four (4) small clearcuts in 2010 and twenty-nine (29) small clearcuts in 2011. The species and diameter of trees > 2 m in height were recorded within 1 m or 2 m-radius plots and used to calculate the biomass fraction of each species. The 2010 study additionally measured the density of trees 2 m in height and the diversity of understory non-tree species. Non-metric multidimensional scaling and multi-response permutation procedures were used to determine the effect of harvest treatment had on community-wide tree species composition. Potential differences were also examined on a species-by-species basis. Both analytic methods indicated no significant differences in species composition of tree species or understory communities. Within the limits of our data, we conclude that no significant effects of residue removal on species composition are observed within our sample of northern hardwood sites at this early stage of stand development.展开更多
文摘The northern forests of are main1y inc1uded two northern forest regions in theNortheast and the Northwest of China.The first region can be subdivided into the boreal conifer and deciduous forest district of the Great Xing’an Mountains and the conifer and deciduous forest district ofLesser Xing’an Mountains;thc second one can be subdivbided into the Northern Montane forest dis-trict of Tianshan Mountains and the Northern Montane coniferous forcst district.It gives a com-pregesive description for the environmental characters,distribution of vegetation and main treespecies of the four distriets.
文摘In the northeastern United States, whole-tree harvesting is widely used to supply fuel to biomass energy facilities, but questions remain regarding its long-term sustainability. We have previously reported findings indicating no short-term decrease in forest productivity in whole-tree harvested sites when compared with similar conventionally (stem-only) harvested sites. Here we present additional results of the same study, but focus on the effect harvest treatment has on the species composition of the regenerating forest. Within northern hardwood forests in central New Hampshire and western Maine, regeneration surveys were conducted on four (4) small clearcuts in 2010 and twenty-nine (29) small clearcuts in 2011. The species and diameter of trees > 2 m in height were recorded within 1 m or 2 m-radius plots and used to calculate the biomass fraction of each species. The 2010 study additionally measured the density of trees 2 m in height and the diversity of understory non-tree species. Non-metric multidimensional scaling and multi-response permutation procedures were used to determine the effect of harvest treatment had on community-wide tree species composition. Potential differences were also examined on a species-by-species basis. Both analytic methods indicated no significant differences in species composition of tree species or understory communities. Within the limits of our data, we conclude that no significant effects of residue removal on species composition are observed within our sample of northern hardwood sites at this early stage of stand development.
