Soil nutrient patchiness affects nutrient use efficiency,though not photosynthesis and growth of parental Glechoma longituba ramets:both patch contrast and direction matter  

作　　者：Hao-qin Xiong 

机构地区：[1]State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,Beijing 100093,China [2]Graduate University of Chinese Academy of Sciences,Beijing 100049,China [3]Department of Environmental Science and Engineering,Southwest Forestry University,Kunming 650224,China

出　　处：《Journal of Plant Ecology》2010年第2期131-137,共7页植物生态学报（英文版）

基　　金：National Natural Science Foundation of China(40435014).

摘　　要：Aims Most plants are clonal in nature.Clonal ramets can share water,nutrients and photosynthate,especially when they experience patchy resources.Patch contrast(i.e.a difference in resources among patches)and patch direction(i.e.source–sink relations)are among the basic attributes of spatial patchiness.Here,I hypothesize that young established ramets in nutrient-rich patches support old ramets in nutrient-poor patches when ramets are subjected to different patch contrasts and patch directions.Methods In a greenhouse experiment,old and young ramets of Glechoma longituba were grown in four combinations consisting of patch contrast and patch direction.Minus patch direction refers to a patch combination in which parent ramets grow in nutrient-rich patches while connected daughter ramets grow in nutrient-poor ones and plus patch direction is the opposite direction.Imeasured photosynthesis and fluorescence traits,harvested all ramets,took morphological measures,weighed their dry mass and determined their nutrient uptake and use.Important Findings For parental ramets of G.longituba,patch contrast and patch direction and their interactions had no significant effects on net photosynthetic rate,maximal fluorescence yield,photochemical quenching(quenching refers to any process which decreases the fluorescence intensity of a given substance),non-photochemical quenching,nutrient uptake,biomass and stolon weight ratio.Patch direction alone significantly affected root weight ratio.Large patch contrast enhanced N use efficiency(NUE)and P use efficiency(PUE);plus patch direction decreased NUE,but increased PUE;the patch contrast by patch direction interaction affected PUE and K use efficiency(KUE).There were significant interactions between patch direction and patch contrast on PUE and KUE.It is concluded that soil nutrient patchiness may influence nutrient use strategies,but not nutrient uptake,photosynthesis and growth of parent ramets of G.longituba connected to daughter ramets,and that patch contrast and patch direction join

关 键 词：chlorophyll fluorescence Glechoma longituba growth and allocation nutrient use strategy PHOTOSYNTHESIS soil nutrient patchiness 

分 类 号：TG1[金属学及工艺—金属学]