Photosynthetic response of Scirpus validus and Typha orientalis to elevated temperatures in Dianchi Lake, Southwestern China  

作　　者：XU Jun-ping SUN Mei WANG Hang ZHANG Yun ZHANG Xiao-tang TIAN Kun National Plateau Wetlands Research Center, Southwest Forestry University School of Environment and Energy, South China University of Technology XU Jun-ping;SUN Mei;WANG Hang;ZHANG Yun;ZHANG Xiao-tang;TIAN Kun

机构地区：[1]National Plateau Wetlands Research Center, Southwest Forestry University [2]School of Environment and Energy, South China University of Technology

出　　处：《Journal of Mountain Science》2018年第12期2666-2675,共10页山地科学学报（英文）

基　　金：supported by the National Science Foundation of China (Grant No. 31370497 and 41877346);the Joint Agricultural Projects of Yunnan Province (Grant No. 2017FG001-018);State Forestry Administration Wetlands Conservation Management Center Foundation of China (Grant Nos. 215231 and 215232)

摘　　要：Understanding the effects of simulated warming on photosynthetic performance of aquatic plants may provide strong supports for predicting future dynamics of wetland ecosystems in the context of climate change. The plateau wetlands located in Yunnan province are highly sensitive to climate warming due to their high altitude and cold temperature. Here, we conducted a temperaturecontrolled experiment using two temperature manipulations(ambient temperature as the control and 2℃ higher than ambient temperature as the warmed treatment) to determine the photosynthetic characteristics of two lakeside dominant species(Scirpus validus Vahl and Typha orientalis C. Presl.) in Dianchi Lake. Net photosynthetic rate(P_n), stomatal conductance(G_s), intercellular CO_2 concentration(Ci), and transpiration rate of S. validus that grew under warmed treatment were all significantly higher than those under the control. Gs and Ci of T. orientalis showed similar patterns as S. validus did. For the response curves of Pn to photosynthetic active radiation(P_n-PAR) and intercellular CO_2 concentration(P_n-Ci), S. validus had higher P_n values under elevated temperatures than the control, while Pn-PAR and P_n-Ci curves of T. orientalis did not separate clearly under two temperature scenarios. Both S. validus and T. orientalis had higher maximum net photosynthetic rate, light saturation point, dark respiration rate, the maximum rate of RuBP carboxylation(V_(cmax)), maximum electron transport rate driving RuBP regeneration(J_(max)), the ratio of V_(cmax) to J_(max), triosephosphate utilization, and 1, 5-bishosphate carboxylase ribulose content under warmed treatment than those under the control. This study provides a preliminary step for predicting the future primary production and vegetation dynamics of plateau wetlands in Yunnan province.Understanding the effects of simulated warming on photosynthetic performance of aquatic plants may provide strong supports for predicting future dynamics of wetland ecosystems in the context of climate change. The plateau wetlands located in Yunnan province are highly sensitive to climate warming due to their high altitude and cold temperature. Here, we conducted a temperaturecontrolled experiment using two temperature manipulations(ambient temperature as the control and 2℃ higher than ambient temperature as the warmed treatment) to determine the photosynthetic characteristics of two lakeside dominant species(Scirpus validus Vahl and Typha orientalis C. Presl.) in Dianchi Lake. Net photosynthetic rate(P_n), stomatal conductance(G_s), intercellular CO_2 concentration(Ci), and transpiration rate of S. validus that grew under warmed treatment were all significantly higher than those under the control. Gs and Ci of T. orientalis showed similar patterns as S. validus did. For the response curves of Pn to photosynthetic active radiation(P_n-PAR) and intercellular CO_2 concentration(P_n-Ci), S. validus had higher P_n values under elevated temperatures than the control, while Pn-PAR and P_n-Ci curves of T. orientalis did not separate clearly under two temperature scenarios. Both S. validus and T. orientalis had higher maximum net photosynthetic rate, light saturation point, dark respiration rate, the maximum rate of RuBP carboxylation(V_(cmax)), maximum electron transport rate driving RuBP regeneration(J_(max)), the ratio of V_(cmax) to J_(max), triosephosphate utilization, and 1, 5-bishosphate carboxylase ribulose content under warmed treatment than those under the control. This study provides a preliminary step for predicting the future primary production and vegetation dynamics of plateau wetlands in Yunnan province.

关 键 词：Climate WARMING AQUATIC plant Photosynthesis Plateau wetland Temperature 

分 类 号：P[天文地球]