广东连州田心自然保护区香果树种群及其生境特征

香果树是中国特有的茜草科的单种属植物，1993年被列入国家重点保护植物名录（Ⅱ级）。论文首次报道了广东境内的香果树Emmenopterys henryi最大种群及其群落的基本情况，以期为深入了解该保护植物的生态适应性、种群的生存和发展提供基础资料。2013年采用美国Onset公司产HOBO-U23-002温度-湿度记录仪对广东连州田心梅树冲的香果树种群所处生境进行了为期1年的监测；测定了土壤的理化特性、叶面和旷地的光照强度、香果树群落的物种组成、香果树种群的基径径级结构与高度结构，以及叶片的某些生理生态特性。结果表明，连州田心梅树冲是香果树的适宜生长地，生境的年均气温17.315℃，年均大气相对湿度84.316%；土壤pH5.64，有机质含量1.95%（大于林外旷地的0.50%）；叶面光照强度小于旷地的12%。香果树叶片SPAD值约为40，净光合速率为2.16-12.92μmol·m-2·s-1（以CO2计），蒸腾速率0.29-0.62 mmol·m-2·s-1（以H2O计）。群落中有维管植物33种，其中乔木层17种，以壳斗科的4种为最多，樟科3种次之；除香果树外，群落优势种为灯台树Bothrocaryum controversum、西川朴Celtis vandervoetiana、野黄桂Cinnamomum jensenianum和金叶含笑Michelia foveolata等。连州田心梅树冲的香果树种群共有97个个体，其中Ⅰ级幼苗11株（占11.34%），Ⅱ级幼苗76株（占78.35%），小树9株（占9.28%），中树0株，大树1株（1.03%）；高度为0.20-2.03 m的个体数77株，占总数的79.38%。径级结构和高度结构均表明，种群目前虽暂时处于增长阶段，但因受2008年南岭地区的冰灾影响，能产生果实的大树严重受损，缺失中树阶段的个体，且Ⅰ级幼苗数量少于Ⅱ级幼苗，该种群将在一定时期后因无法更新而进入衰退阶段，为此应加强香果树的就地和迁地保护、科学研究和宣传教育。

Characteristics ofEmmenopterys henryi population and habitat at Tianxin Nature Reserves,Lianzhou city,Guangdong province,China

Emmenopterys henryiis a monotypic genus in the Rubiaceae family which is a national grade II key protected tree species in China. The basic characteristics of the largest population ofE. henryiin Guangdong province including community structure are reported in this paper. To provide basic data and information of ecological adaption, for protecting and enhancing theE. henryi population, the habitat characteristics were also analyzed. Using an automatic sensors of Onset HOBO-U23-002 mini-weather station, the air temperature, relative humidity were monitored for one year （during 2013） at Meishuchong village, Tianxin Nature Reserves, Lianzhou city, in Guangdong province located in areas whereE. henryi grows. Soil physic-chemical characteristics, light intensity （on plant leaf and open areas outside of the forest）, species composition of the community, population characteristics of basal diameter size and height class structure, and eco-physiological indexes ofE. henryi leaf were measured. Results showed that Meishuchong village is a suitable field site for growing E. henryi. The mean annual air temperature was 17.315℃, and the mean annual air relative humidity was 84.316% at the field site. Soil pH was 5.64 with an organic matter content of 1.95% which was higher than that of 0.50% of open areas outside the forest. The light intensity on the leaves was 12% which was less than that of open area outside of the forest. The leaf SPAD values was around 40, and the leaf net photosynthesis rate and transpiration rate ofE. henryi was 2.16 to 12.92μmol·m-2·s-1（calculated by CO2） and 0.29 to 0.62 mmol·m-2·s-1 （calculated by H2O）, respectively. There were 33 vascular plant species in the community. Among the group, 17 tree species were arbor, in which the largest family was Fagaceae with four species, the second most abundant family was Lauraceae with three species. Except forE. henryi, the dominant tree species of the community wereBothrocaryum controversum,Celtis vandervoetiana,Cinnamomum jensenianum, a