不同林分内茶树光合特性及其影响因子和小气候因子分析

对板栗-银杏-茶(Castanea mollissima-Ginkgo biloba-Camellia sinensis)和板栗-茶(Castanea mollissima-Camellia sinensis)复合林分和纯茶(Camellia sinensis)林分内3个小气候因子包括光合有效辐射强度(PAR)、空气温度(Ta)和空气相对湿度(RH)]和茶树光合特性包括净光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)和蒸腾速率(Tr)]的差异进行了比较,并采用多元回归分析探讨了影响茶树Pn的主要生理生态因子.结果表明:在不同测定时期3种林分内PAR、Ta和RH差异较大；同一时期纯茶林分内的PAR和Ta基本都高于2种复合林分,但纯茶林分内的RH总体上均低于2种复合林分；与纯茶林分相比,板栗和银杏与茶树复合种植有助于调节林分内的PAR、Ta和RH.2种复合林分内茶树的生长均受到板栗或银杏阴蔽的影响,纯茶林分中茶树的Pn最高,与板栗-银杏-茶复合林分内茶树的Pn有显著差异；而纯茶林分中茶树的Gs总体上高于复合林分、Ci与复合林分间差异不显著,且3种林分中茶树的Tr总体上也无显著差异.多元回归分析结果表明:在6个生理生态因子(Gs、Ci、Tr、PAR、Ta 和RH)中,Tr对3种林分内茶树的Pn影响最大,其次是Ta,其他因子在各种林分内的影响程度不同.研究结果表明:茶树复合种植可调节林分内的水热状况,改善茶树生长环境,值得在现有茶园中进行推广和应用.

Analyses on photosynthetic characteristics of Camellia sinensis in different forests and its main impact factors and microclimate factors

Differences of three microclimate factors including photosynthetically active radiation intensity(PAR),air temperature(Ta) and air relative humidity(RH) and photosynthetic characteristics including net photosynthetic rate(Pn),stomatal conductance(Gs),intercellular CO2 concentration(Ci) and transpiration rate(Tr) of Camellia sinensis(L.) O.Kuntze in compound forests of Castanea mollissima-Ginkgo biloba-Camellia sinensis and Castanea mollissima-Camellia sinensis and pure forest of Camellia sinensis were compared,and the main physio-ecological factors affecting on Pn of C.sinensis were investigated by multiple regression analysis.The results show that there are great differences of PAR,Ta and RH in three forests during different measurement times,PAR and Ta in pure forest of C.sinensis are generally higher but its RH is generally lower than those in two compound forests during same measurement time.Compared to pure forest of C.sinensis,compound planting of C.mollissima and G.biloba with C.sinensis is helpful to regulate PAR,Ta and RH in the forests.The growth of C.sinensis is affected by shading of C.mollissima or G.biloba in two compound forests.Pn of C.sinensis in pure forest is the highest with significant difference to that of C.sinensis in C.mollissima-G.biloba-C.sinensis compound forest.And Gs of C.sinensis in pure forest is generally higher than and its Ci has no significant difference with that in two compound forests.Also,Tr of C.sinensis generally has no significant difference among three forests.The results of multiple regression analysis indicate that effect of Tr on Pn of C.sinensis in three forests is the greatest among six physio-ecological factors(including Gs,Ci,Tr,PAR,Ta and RH),and the second is Ta.While other factors have different effect degrees in different forests.It is suggested that compound planting of C.sinensis can regulate water and heat conditions within forests and improve growing environment of C.sinensis,it is worth for popularization and application in existing tea garden.