安吉毛竹林生态系统光合作用特征及其环境影响因子研究

摘要

以浙江省安吉县毛竹(Phyllostachy sedulis)林生态系统为研究对象,利用开路涡度相关系统测定了2014年毛竹林生态系统CO2通量特征,首次利用涡度相关法分析了毛竹林生态系统光合作用特征及其影响因子.结果表明:生态系统最大光合速率(Pmax)、暗呼吸速率(Rd)和初始量子效率(α)均具有明显的月变化特征,各参数的变化范围分别为0.3765~1.5257 mg/(m2·s)、0.0016~0.0024 mg/(m2·s)、0.0785~0.2695 mg/μmol,毛竹林总生态系统生产力GEP年总量为1596.22 g C/(m2·a).影响毛竹林生态系统Pmax和GEP的主要环境因子是温度、光合有效辐射、叶面积指数和饱和水汽压差,Pmax和GEP均随着温度、光合有效辐射和一定范围内的叶面积指数的增加而增长,SWC50 cm也是影响Pmax和GEP的重要环境因子(P<0.05),SWC5 cm对二者的影响均不明显(P>0.05).%The carbon flux of the subtropical bamboo forest ecosystem in Anji County of Zhejiang Province was measured using eddy covariance technique in 2014.The photosynthetic characteristics of the bamboo forest e-cosystem and related environmental controlling factors were analyzed by the eddy covariance micrometeorological method.The results showed that the maximum photosynthesis rate(Pmax),respiration(Rd)and apparent quantum yield(α) and gross ecosystem production ( GEP ) had characteristics of obvious mouthly changes. The monthly mean initial light use efficiency(α),maximum photosynthesis rate(Pmax)and dark ecosystem respiration(Rd) varied from 0.3765 to 1.5257 mg/( m2 ·s) ,0.0016 to 0.0024 mg/( m2 ·s) ,0.0785 to 0.2695 mg/μmol re-spectively.The total amount of gross ecosystem production(GEP)was 1596.22 g C/(m2·a).The major environ-mental factors affecting Pmax and GEP were temperature,Photosynthetically active radiation(PAR),leaf area index( LAI) and vapor pressure deficit( VPD);monthly mean Pmax and GEP increased with the increase of tem-perature,photosynthetically active radiation(PAR),leaf area index(LAI) within a certain range.As affected by the interaction of air temperature( Ta ) and vapor pressure deficit( VPD) ,soil water content at 50 depth was an-other important environmental factor affecting Pmax and GEP,and Pmax and GEP were significantly related to the water content.