水保所知识产出(1956---)知识库

Within limited growth age in some regions, forest production, including gross primary production (GPP) and net primary
production (NPP), was linearly correlated with leaf area index (LAI). However, over wide range of growth age in the global
scale, LAI patterns of forest production are unclear. Here, we compiled a subset from the Global Soil Respiration Database
(SRDB) for globaltemperate forestecosystems. Thesubsetdatabasemainly includedforestproduction,soilrespiration,and LAI
data in 493 study sites over wide range of forest growth age (0–500 years). The results showed that LAI initially increased
rapidly,reachedapeakatjuvenility,decreasedslowlyuntilmaturity,andagainincreasedpossiblywithfurtherforestaging(R 2 =
0.21, P<0.001). We found that the dynamics of both GPP and NPP across global temperate forest ecosystems were driven by
LAI. GPP initially increased and subsequently stabilized with increasing LAI. NPP peaked at LAI of about 5.6 m 2 m −2 , and
subsequently decreased. The decrease in NPP resulted from the asymptotic increase in GPP and the continuing decrease in the
NPP/GPP ratio with increasing LAI. The decline in the NPP/GPP ratio resulted from the significant increase in autotrophic
respiration (R a ),and especiallyafter canopyclosure,R a increasedmorequicklywithincreasingLAIthanGPP.These results will
improve our understanding of the control of LAI on ecosystem production.