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Biomass Estimates And Its Spatial Pattern Of A Primary Temperate Forest In Xiaoxing'an Mountains, Northeast China

Posted on:2011-06-11Degree:MasterType:Thesis
Country:ChinaCandidate:R LiFull Text:PDF
GTID:2120360308971290Subject:Ecology
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Accurate estimation of the storage and spatial distribution of biomass in forest ecosystems is essential when quantifying character of the forest ecosystem and forest carbon stocks. Appropriate methods and reliable data are necessary. In this study, the biomass and its spatial distribution pattern of a primeval broad-leaved Korean pine forest was studied based on a 9 hm2 large permanent sample plot. We divided the forest ecosystem into components with detaile, and then using suitable methods to estimate the biomass of each component. Based on the biomass estimate results of tree and shrub layers (all stems DBH≥2 cm) and CWD from the 9 hm2 large permanent sample plot, we used the semivariance analysis of geostatistics and topographic analysis to detect the spatial distribution pattern of the biomass.The results showed as follows:(1) Total biomass for the primeval broad-leaved Korean pine forest was 393.78 t·hm-2, which living biomass made up 91.41%, CWD and litter were 6.68% and 1.91% respectively. (2) Total living biomass (belowground+aboveground) was estimated to be 105.17 t·hm-2 and 260.99 t·hm-2, and root:shoot ratio (R/S) was 0.40. In the allocation of biomass of tree and shrub layers, stems accounted for 52.92%, and coarse roots, branches and leaves were 27.56%,15.48% and 4.04%, respectively. The biomass allocation among different DBH classes was concentrated in the median and large classes, with trees (DBH>20 cm) accounting for 93.36%, large trees (DBH>70 cm) occurred a low frequency in the forest, but they were accounted for 20.98% of the total biomass of tree and shrub layers. The vertical allocation of the biomass in tree and shrub layers was:the sub-layerⅠ(H>30 m) 103.65 t·hm-2, the sub-layerⅡ(20~30 m)181.02 t·hm-2, the sub-layerⅢ(10~20 m)65.83 t·hm-2, and the sub-layerIV(H≤10 m) 8.87 t·hm-2. Over 97% of the biomass is due to 10 species only,70.34% of the biomass was contributed by the obvious dominant tree Pinus koraiensis. (3) CWD biomass storage amounted to 26.77 t·hm-2, of which downed wood, Standing die, Trunk segment were 21.04 t·hm-2,4.14 t·hm-2 and 1.58 t·hm-2, respectively. The decay classes of CWD were largely distributed on the decay classⅡandⅢ, Pinus koraiensis, Betula costata, Abies nephrolepis, Picea koraiensis, Tilia amurensis were the main contributors for the biomass of CWD. (4) The semivariograms of biomass of different component in tree and shrub layers(Stems, Branches, Leaves, Roots, AGB, Lived total) and CWD were best described by fitting models, the spatial variability of all of them were mainly caused by structural factors with spatial structure ration> 75%, the scales of spatial heterogeneity of them were 96.9,138.4,110.1,91.8,98.4,94.8 and 79.5 m respectively. There are high levels of variation in spatial heterogeneity and scale patterns among the five main species(Pinus koraiensis, Betula costata, Abies nephrolepis, Tilia amurensis, Acer mono), the spatial variability of all of them were mainly caused by structural factors with spatial structure ration> 75%, the scales of spatial heterogeneity of them were 110.7,49.7,56.4,43.1 and 51.6 m respectively. (5) Topographic position and aspect were the most impotant topographical factors influcing the biomass of tree and shrub layers. The biomass increased with topographic position assceding and then decreased, and it decreased with the change of the aspect-shady, semi-shady, half-sunny, sunny, flat, and showed significant difference by x2 test (P< 0.001), while the slope showed no significant difference on the biomass of tree and shrub layers (P> 0.05). The distribution of CWD biomass on three topographic levels (topographic position, aspect, and slope) showed no significant difference (P> 0.05).
Keywords/Search Tags:Biomass, Biomass allocation, Spatial pattern, Large permanent sample plot, Primeval broad-leaved Korean pine forest
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