不同地理种源西南桦苗木的耐热性研究

由于受全球气候变化的影响，近年来我国一些地区出现了异常高温天气，这越来越引起林业工作者的重视。以亚热带珍贵用材树种西南桦为研究对象，以采集于我国广西和云南两省区12个种源的西南桦种子所育苗木为实验材料，对不同种源苗木在41C高温处理下的生理指标(叶片电导率、净光合速率、蒸腾速率和根系活力)的变化进行了综合评价，来选择耐热性优良的种源。结果表明，各生理指标在高温处理后与处理前相比发生了较为明显的变化，其中，叶片电导率增高为对照温度(25C)的1．2倍，光合速率、蒸腾速率和根系活力则分别只有对照温度的60％、21％和6％；方差分析发现，在对照温度下，各生理指标在不同种源间的差别不明显，而在41C高温处理后，这种差异达到显著程度。用模糊数学的隶属度函数对参加试验的12个种源西南桦苗木的耐热性进行综合评价发现，凌云种源的耐热性最强，建议作为推荐优先发展的种源。

The research of heat-tolerance of different provenances of Betula alnoides seedlings

In accordance with the global climate changes, abnormal high temperature has occurred in recent years in some regions in China and the influences of such high temperature stress on tree growth have increasingly drawn attention of foresters. In this paper, provenance variation of heat tolerance in a subtropical valuable tree species, Betula alnoides, was studied. A total of 12 provenances seedlings cultivated from seeds, which were collected from Guangxi and Yunnan Provinces in China, were employed. F...