According to the data of wood analysis and biomass invcstigation, wc analyse the relationship among scotch pine stock, the growth of volume and its density, thc relationship between bio-productivity and its density as...According to the data of wood analysis and biomass invcstigation, wc analyse the relationship among scotch pine stock, the growth of volume and its density, thc relationship between bio-productivity and its density as well as the law of the distribution of biomass of various organs of the scotch pine. The conclusions showcd that the stock, volume, growth, bio produetivity and its density were interrclated closely. The appropriate density was 620--820 individuls / hm2 of mid-aged trees. The distributions of biomass on various organs werc different at different age stage. This paper gave the evidence to value artificial scotch pine, its structures and functions.展开更多
Aims Understanding carbon(C)and nitrogen(N)dynamics and their dependence on the stand density of an even-aged,mature forest provides knowledge that is important for forest management.This study investigated the differ...Aims Understanding carbon(C)and nitrogen(N)dynamics and their dependence on the stand density of an even-aged,mature forest provides knowledge that is important for forest management.This study investigated the differences in ecosystem total C and N storage and flux between a low-density stand(LD)and a high-density stand(HD)and examined the effects of stand density on aboveground net primary productivity(ANPP),total belowground C allocation(TBCA)and net ecosystem production(NEP)in a naturally regenerated,65-to 75-year-old Pinus densiflora S.et Z.forest.Methods LD(450 trees ha^(−1))and HD(842 trees ha^(−1))were established in an even-aged,mature P.densiflora forest in September 2006.The forest had been naturally regenerated following harvesting,and the stand density was naturally maintained without any artificial management such as thinning.The diameter at breast height(DBH≥5.0cm)of all live stems within the stands was measured yearly from 2007 to 2011.To compare C and N storage and fluxes in LD and HD,C and N pools in aboveground and belowground biomass,the forest floor,coarse woody debris(CWD)and soil;soil CO_(2) efflux(R_(S));autotrophic respiration(R_(A));litter production;and soil N availability were measured.Further,ANPP,TBCA and NEP were estimated from plot-based measurement data.Important Findings Ecosystem C(Mg C ha^(−1))and N(Mg N ha^(−1))storage was,respectively,173.0±7.3(mean±SE)and 4.69±0.30 for LD and 162±11.8 and 4.08±0.18 for HD.There were no significant differences in C and N storage in the ecosystem components,except for soils,between the two stands.In contrast,there were significant differences in aboveground ANPP and TBCA between the two stands(P<0.05).Litterfall,biomass increment and R_(S) were major C flux components with values of,respectively,3.89,3.74 and 9.07 Mg C ha^(−1) year^(−1) in LD and 3.15,2.94 and 7.06 Mg C ha^(−1) year^(−1) in HD.Biometric-based NEP(Mg C ha^(−1) year^(−1))was 4.18 in LD and 5.50 in HD.Although the even-aged,mature P.densiflora forest had similar C and N allocation patterns,it showed different C and N dynamics depending on stand density.The results of the current study will be useful for elucidating the effects of stand density on C and N storage and fluxes,which are important issues in managing natural mature forest ecosystems.展开更多
文摘According to the data of wood analysis and biomass invcstigation, wc analyse the relationship among scotch pine stock, the growth of volume and its density, thc relationship between bio-productivity and its density as well as the law of the distribution of biomass of various organs of the scotch pine. The conclusions showcd that the stock, volume, growth, bio produetivity and its density were interrclated closely. The appropriate density was 620--820 individuls / hm2 of mid-aged trees. The distributions of biomass on various organs werc different at different age stage. This paper gave the evidence to value artificial scotch pine, its structures and functions.
基金National Research Foundation of Korea(2006-000108630,2009-0076529,A307-K004:JSPS-NRF-NSFC A3 Foresight Program)Korea University(2013).
文摘Aims Understanding carbon(C)and nitrogen(N)dynamics and their dependence on the stand density of an even-aged,mature forest provides knowledge that is important for forest management.This study investigated the differences in ecosystem total C and N storage and flux between a low-density stand(LD)and a high-density stand(HD)and examined the effects of stand density on aboveground net primary productivity(ANPP),total belowground C allocation(TBCA)and net ecosystem production(NEP)in a naturally regenerated,65-to 75-year-old Pinus densiflora S.et Z.forest.Methods LD(450 trees ha^(−1))and HD(842 trees ha^(−1))were established in an even-aged,mature P.densiflora forest in September 2006.The forest had been naturally regenerated following harvesting,and the stand density was naturally maintained without any artificial management such as thinning.The diameter at breast height(DBH≥5.0cm)of all live stems within the stands was measured yearly from 2007 to 2011.To compare C and N storage and fluxes in LD and HD,C and N pools in aboveground and belowground biomass,the forest floor,coarse woody debris(CWD)and soil;soil CO_(2) efflux(R_(S));autotrophic respiration(R_(A));litter production;and soil N availability were measured.Further,ANPP,TBCA and NEP were estimated from plot-based measurement data.Important Findings Ecosystem C(Mg C ha^(−1))and N(Mg N ha^(−1))storage was,respectively,173.0±7.3(mean±SE)and 4.69±0.30 for LD and 162±11.8 and 4.08±0.18 for HD.There were no significant differences in C and N storage in the ecosystem components,except for soils,between the two stands.In contrast,there were significant differences in aboveground ANPP and TBCA between the two stands(P<0.05).Litterfall,biomass increment and R_(S) were major C flux components with values of,respectively,3.89,3.74 and 9.07 Mg C ha^(−1) year^(−1) in LD and 3.15,2.94 and 7.06 Mg C ha^(−1) year^(−1) in HD.Biometric-based NEP(Mg C ha^(−1) year^(−1))was 4.18 in LD and 5.50 in HD.Although the even-aged,mature P.densiflora forest had similar C and N allocation patterns,it showed different C and N dynamics depending on stand density.The results of the current study will be useful for elucidating the effects of stand density on C and N storage and fluxes,which are important issues in managing natural mature forest ecosystems.
