海南龙血树野生资源分布及其与水热关系的分析

Geographical Distribution of Wild Dracaena cambodiana in China and Its Relationship with Hydrothermal Factors

摘要:

在全面调查海南龙血树(Dracaena cambodiana)野生资源地理分布的基础上,用温度指数、湿度指数等气候指标分析了海南龙血树野生资源地理分布与气候因子间的关系。结果表明,海南龙血树野生资源在中国仅分布于海南岛西南部山区及南部沿海地区,水平分布于108°42′40.9″~110°27′36.8″E,18°14′27″~19°20′28.5″N,垂直分布范围为0~900 m,仅发现10 个现存分布点;海南龙血树属于热带雨林、季雨林小乔木状植物,具有强耐旱、喜阳和喜钙等生态习性,其分布区的绝大部分水热因子是其分布的主要限制因子。主成分分析表明,影响海南龙血树地理分布的主要水热指标的排序为热量因子>降水因子>湿度因子。根据野生居群的生境特点,我们推测水分和光照强度可能是影响海南龙血树种子萌发率或幼苗成活率的重要因子。

Abstract:

The geographical distribution of wild resources of Dracaena cambodiana in China was comprehensively investigated and its relationship with climatic factors was analyzed by climate indexes, such as Kira’s warmth index, Xu’s humidity index, et al. The results showed that D. cambodiana was endemic to southwestern mountains and southern coastal areas of Hainan Island in China, with horizontal distribution from 108°42'40.9" to 110°27'36.8"E, and 18°14'27" to 19°20'28.5"N, and vertical distribution at 0-900 m altitude, and only ten distribution locations were found. The D. cambodiana is a small tree species of tropical rainforest or monsoon forest with ecological habitats of drought tolerance and heliophytes and calcicole, and most of hydrothermal factors were the main limited factors to its geographical distribution. The principal component analysis showed that the dominant factors on the distribution of D. cambodiana were in order as thermal factors > precipitation factors > relative humidity factors. Based on the habitat characteristics of wild populations, it suggested that both moisture and light intensity have significant effects on seed germination and seedling survival of D. cambodiana.