广西海岸红鳞蒲桃林主要树种的温度胁迫

Extreme Temperature Stress on Dominant Trees of Syzygium hancei Forest Along Guangxi Coast

利用电导率和Logistic方程研究广西海岸红鳞蒲桃(Syzygium hancei)季雨林主要树种的抗热性和抗寒性,按半致死温度高低判断这些树种的抗极端温度胁迫能力。结果红鳞蒲桃季雨林主要树种的高温胁迫半致死温度顺序为:竹节树(Carallia brachiata)62.52℃>紫荆木(Madhuca pasquieri)53.66℃>膝柄木(Bhesasinica)50.62℃>豺皮樟(Litsea rotundifoliavar.oblongifolia)49.36℃>红鳞蒲桃48.62℃,远低于广西海岸历史极端高温38.2℃。红鳞蒲桃季雨林主要树种的低温胁迫半致死温度顺序为:竹节树-0.6℃>紫荆木-4.03℃>膝柄木-5.42℃>豺皮樟-5.7℃>红鳞蒲桃-6.93℃,与广西海岸历史极端低温-1.8℃比较接近。低温胁迫是竹节树等季雨林种群生存与发展的重要制约因素。

The hardy capacity to extreme cold and heat of dominant trees in Syzygium hancei monsoon forest along Guangxi coast was studied by means of the relative electrical conductivity method and Logistic equations. Semilethal temperature （LT50） is the index to represent the temperature hardy capacity of these trees. The results show that heat LTso is sequentially 62.52 ℃ of Carallia brachiata 〉53.66℃ ofMadhuca pasquieri〉50.62℃ of Bhesa sinica 〉49.36℃ of Litsea rotundifolia var. oblongifolia -48.62℃ of S. hancei , all of which are much higher than the extreme heat tempature of 38.2℃ on Guangxi coast. The cold LTs0 is sequentially --0. 6℃ ofC. brachiata 〉-4. 03℃ ofM. pasquieri 〉 -5.42℃ of B. sinica -5. 7℃ of L. rotundifolia var. oblongifolia -6.93℃ of S. hancei ,all of which are subequal to the extreme cold tempature of -1.8℃ on Guangxi coast. Accordingly cold stress is an important constraint to limit the growth and spread of population of C. brachiata and so on.