Photosynthate supply drives soil respiration of Fraxinus mandshurica seedlings in northeastern China： evidences from a shading and nitrogen addition experiment  

作　　者：Yanli Jing Dexin Guan Jiabing Wu Anzhi Wang Changjie Jin Fenghui Yuan 

机构地区：[1]Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences,Shenyang 110164, People's Republic of China [2]University of Chinese Academy of Sciences, Beijing 100049,People's Republic of China

出　　处：《Journal of Forestry Research》2016年第6期1271-1276,共6页林业研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(41375119,31400541);the Key Laboratory of Forest and Soil Ecology(LFSE2013-11)

摘　　要：Improved understanding of the link between photosynthesis and below-ground processes is needed to better understand ecosystem carbon （C） cycling and its feedback to climate change. We conducted a short-term shading and nitrogen （N） addition experiment from June to September 2013 to investigate the effect of photosynthate supply by Manchurian Ash （Fraxinus mandshurica） seed- lings on soil respiration （SR）. Shading significantly reduced SR in early and middle growing season, but not in late growing season, leading to a decrease in mean SR by 24 % in N-unfertilized treatments. N addition increased mean SR by 42 % in un-shaded treatment. The stimulation of SR was largely attributed to accelerated autotrophic respiration by increasing photosynthesis, leaf area index and belowground biomass. Shading reduced mean SR by 32 % in N addition treatment. The strengthened shading effect on SR resulted from N addition was because of more photosynthates supply at low soil temperature. Our findings highlight the predominance of photosynthates supply in regulating the responses of C cycling to global change.Improved understanding of the link between photosynthesis and below-ground processes is needed to better understand ecosystem carbon （C） cycling and its feedback to climate change. We conducted a short-term shading and nitrogen （N） addition experiment from June to September 2013 to investigate the effect of photosynthate supply by Manchurian Ash （Fraxinus mandshurica） seed- lings on soil respiration （SR）. Shading significantly reduced SR in early and middle growing season, but not in late growing season, leading to a decrease in mean SR by 24 % in N-unfertilized treatments. N addition increased mean SR by 42 % in un-shaded treatment. The stimulation of SR was largely attributed to accelerated autotrophic respiration by increasing photosynthesis, leaf area index and belowground biomass. Shading reduced mean SR by 32 % in N addition treatment. The strengthened shading effect on SR resulted from N addition was because of more photosynthates supply at low soil temperature. Our findings highlight the predominance of photosynthates supply in regulating the responses of C cycling to global change.

关 键 词：Autotrophic respiration Carbon FERTILIZATION SHADING Substrate supply 

分 类 号：S792.41[农业科学—林木遗传育种]