极小种群野生植物海南假韶子群落土壤特性研究

Study on soil characteristics and differences in the distribution area of extremely small population of Paranephelium hainanensis community

以极小种群野生植物海南假韶子Paranephelium hainanensis集中分布区三亚市落笔洞和亚龙湾热带天堂森林公园两个群落为研究对象,以未见海南假韶子分布的次生林为对照林分,采用土壤理化性质常规及氯仿熏蒸浸提法测定方法对海南假韶子群落的土壤理化性质、土壤微生物和土壤酶活性进行研究。结果表明:(1)海南假韶子所在落笔洞和森林公园群落土壤呈酸性,全磷含量较为缺乏;两个群落非根区土的土壤有机质、碱解氮、有效磷、速效钾、交换性钙和交换性镁含量均高于对照林分;森林公园群落根区土的土壤有机质、全钾、碱解氮和交换性镁含量均显著高于落笔洞群落。(2)两个群落非根区土的土壤微生物生物量碳和氮均高于对照林分;落笔洞群落根区土的土壤微生物生物量碳含量(1 081.92 mg?kg^(-1))和微生物生物量C/N(15.79)高于森林公园群落根区土。(3)两个群落非根区土的土壤酶活性也高于对照林分;森林公园群落根区土的土壤酸性磷酸酶(726.18 mg?kg^(-1))和脲酶(1 445.63 mg?kg^(-1))活性显著高于落笔洞群落,但群落间的土壤过氧化氢酶差异不显著。(4)PCA结果表明,海南假韶子不同群落对土壤因子响应较为显著,能较好地区别落笔洞和森林公园群落;同一群落根区土与非根区土对土壤因子响应也不同。这些结果为进一步探究海南假韶子对异质性土壤的适应性奠定了基础。

Based on the Paranephelium hainanensis community distributed in Luobidong and Bay Tropical Paradise forest park of Sanya city, with no P. hainanensis distributed of secondary forest to control. The soil physical and chemical properties, soil microbial biomass and soil enzyme activity were studied by using the soil physical and chemical properties and the method of chloroform fumigation extraction. The results showed that：（1） The soil was acidic in Luobidong and Forest Park communities, which the contents of total phosphorus was poverty, respectively. The contents of organic matters, available nitrogen, available phosphorus, rapidlyavailable potassium, exchangeable calcium and exchangeable magnesium in the non-planted soil soils of the two communities were higher than control forest.（2） The non-planted soil of two communities of the soil microbial biomass carbon and soil microbial biomass microbial were higher than control forest. The soil microbial biomass carbon（1 081.92 mg·kg^-1） and soil microbial biomass C/N（15.79） at the rhizospheric soil of Luobidong community were higher.（3） The non-planted soil of two communities of the soil enzyme activity also was higher than control forest, respectively. The activity of soil acid phosphatase（726.18 mg·kg^-1） and urease（1 445.63 mg·kg^-1） were significantly higher than Forest Park community. However, there were no significant differences in the soil catalase activity between Luobidong and Forest Park community.（4） Principal Component Analysis（PCA） showed that there was significant correlation with difference P. hainanensis communities, which it could distinguish between Luobidong and Forest Park community. The soil response of the non-planted soil and rhizospheric soil in the same community was difference. These results lay a foundation for further exploration of the adaptability heterogeneous of P. hainanensis.