粗齿桫椤和金毛狗的生理生态及其生境特征研究

The Characteristics of Eco-physiological and the Habitat of Gymnosphaera hancockii and Cibotium barometz

对广东天井山自然分布的国家保护植物粗齿桫椤和金毛狗,以及邻近生长的狗脊叶片进行了生理生态特性测定;用温湿度自动记录仪监测了2013年其生境的温湿度,测定了土壤的理化特性、光照强度,以期为它们的生存和发展提供参考.结果表明:生境年均气温17.896℃,年均相对湿度91.703%;土壤pH4.46,有机质含量2.20%.林内光照强度不足旷地的18%.叶片SPAD值和平均的净光合速率粗齿桫椤<金毛狗<狗脊,蒸腾速率则为粗齿桫椤>狗脊>金毛狗,3种植物均对低光照有较好的适应性.粗齿桫椤表现出低光合速率高蒸腾速率,有可能导致其生长较缓慢.

The leaf eco-physiological characteristics of national key protected species of Gymnosphaera hancockii,Cibotium barometz and Woodwardia japonica nearby were determined at nature growing habitat in Tianjingshan,Guangdong. Using an automatic onset HOBO mini-weather station,the air temperature,and the air relative humiditywere monitored for one year（2013）at the field site. The soil physic-chemical characteristics,the light intensity ofinner and open outside of the forest were also measured in order to provide basic data for protecting and enhancingthe plant population. Results showed that the mean annual air temperature was 17.896 ℃,and the mean annual airrelative humidity was 91.703%. Soil p H was 4.46 with organic matter content of 2.20%. The light intension innerthe forest was 18% less than that of open outside of the forest. The leaf SPAD values and mean net photosynthesisrate showed that of G. hancockii〈C. barometz〈W. japonica,meanwhile the transpiration rate showed that of G.hancockii〉W. japonica〉C. barometz. All of the three species were adapted to the low light intension. The results oflower photosynthesis rate and higher transpiration rate of G. hancockii suggested that the lower growth speed.