Autumn sunlight promotes aboveground carbon loss in a temperate mixed forest  

作　　者：Xingzhi Li Yanan Wang Juanjuan Zhang Thomas Matthew Robson Hiroko Kurokawa Huan Peng Li Zhou Dapao Yu Jiaojiao Deng Qing‑Wei Wang 

机构地区：[1]CAS Key Laboratory of Forest Ecology and Silviculture,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Changbaishan Xipo National Field Observation and Research Station for Forest Ecosystem,Baishan 134500,China [4]UK National School of Forestry,University of Cumbria,Ambleside LA229BB,UK [5]Organismal and Evolutionary Biology,Viikki Plant Science Centre(ViPS),University of Helsinki,P.O.Box 65,00014 Helsinki,Finland [6]Forestry and Forest Products Research Institute,1 Matsunosato,Tsukuba,Ibaraki 3058687,Japan

出　　处：《Ecological Processes》2024年第3期92-107,共16页生态过程(英文)

基　　金：funded by the National Natural Science Foundation of China(32122059);the National Key R&D Program of China(2021YFD2200402);Chi‑nese Academy of Sciences Young Talents Program,and Liaoning Revitalization Talents Program(XLYC2007016)to QWW;by Chinese Academy of Sciences President’s International Fellowship Initiative(2022VCA0010);the Japan Society for the Promotion of Science(KAKENHI,17F17403)to QWW and HK;Academy of Finland Project(324555)to TMR.

摘　　要：Background Photodegradation of plant litter plays a pivotal role in the global carbon(C) cycle. In temperate forest ecosystems, the exposure of plant litter to solar radiation can be significantly altered by changes in autumn phenol-ogy and snow cover due to climatic change. How this will affect litter decomposition and nutrient dynamic interact-ing with forest canopy structure(understorey vs. gaps) is uncertain. In the present study, we conducted a field experi-ment using leaf litter of early-fall deciduous Betula platyphylla(Asian white birch) and late-fall deciduous Quercus mongolica(Mongolian oak) to explore the effect of change in autumn solar radiation on dynamics of litter decompo-sition in a gap and understorey of a temperate mixed forest.Results Exposure to the full-spectrum of not only significantly increased the loss of mass, C, and lignin, but also mod-ified N loss through both immobilization and mineralization during the initial decomposition during autumn canopy opening, irrespective of canopy structure and litter species. These effects were mainly driven by the blue-green spectral region of sunlight. Short-term photodegradation by autumn solar radiation had a positive legacy effect on the later decomposition particularly in the forest gap, increasing mass loss by 16% and 19% for Asian white birch and Mongolia oak, respectively.Conclusions Our results suggest that earlier autumn leaf-fall phenology and/or later snow cover due to land-use or climate change would increase the exposure of plant organic matter to solar radiation, and accelerate ecosys-tem processes, C and nutrient cycling in temperate forest ecosystems. The study provides a reference for predictive research on carbon cycling under the background of global climate change.

关 键 词：Carbon cycling Canopy phenology Snow cover Climate warming Solar radiation Photodegradation 

分 类 号：S718.5[农业科学—林学]