广西天坑森林物种多样性与土壤酶活性和养分的关系

Relationships among species diversity and soil enzyme activities and nutrient contents in tiankeng forests, Guangxi

关键词:  植物多样性, 土壤养分, 土壤酶活性, 天坑森林, 土壤磷含量

Key words:  plant diversity, soil nutrients, soil enzyme activities, Tiankeng forest, soil phosphorus content

摘要:

为研究天坑负地形生境土壤酶活性、养分和木本植物多样性的分布特征和内在联系,该文以广西大石围天坑群天坑森林为研究区,基于天坑坑内—坑口—坑外群落多样性调查和土壤生境调查,采用相关性分析和冗余分析方法,探究木本植物物种多样性与土壤因子间的耦合关系。结果表明:(1)坑内木本植物有21种31属20科,坑口木本植物有91种58属58科,坑外木本植物有47种30属30科,天坑坑内Margalef指数和Patrick指数显著低于天坑坑口和坑外生境,沿天坑坑内—坑口—坑外生境变化,物种分布总体较为均匀,但物种数量增多。(2)天坑坑外土壤全氮含量显著高于坑内和坑口生境,坑内的土壤全镁、土壤全磷和土壤速效磷含量显著高于坑口和坑外生境,坑外的土壤碱性磷酸酶和土壤脲酶活性显著高于坑口和坑内生境,表明天坑坑内土壤磷含量较高,但土壤酶活性总体偏低。(3)物种多样性与土壤养分、土壤酶活性相关性强。综上表明,天坑生境对物种多样性、土壤酶活性及土壤养分含量的分布特征影响较大,土壤速效磷、土壤碱性磷酸酶、土壤含水量、土壤脲酶、土壤全镁和土壤全磷是影响天坑森林木本植物物种多样性的关键因子。该研究为喀斯特地区植物资源的保护与重建提供了理论基础。

Abstract:

In order to study, the distribution characteristics and internal links of soil enzyme activities, nutrient content and woody plant diversity in negative topographic habitats of tiankeng, the tiankeng forests of the Dashiwei tiankeng group in Guangxi were selected as the object, and the relationship between species diversity and soil factors of woody plants was explored by correlation analysis and redundancy analysis methods, based on the community diversity survey and soil habitat survey along the inner area-top area-outer area of tiankeng. The results were as follows:(1)There were 21 species, 31 genera and 20 families of woody plants in the inside area of tiankeng, 91 species, 58 genera and 58 families of woody plants in the top area of tiankeng, and 47 species, 30 genera and 30 families of woody plants in the outside area of tiankeng. The Margalef index and Patrick index in the inside areas of tiankeng were significantly lower than those in the top and outside areas of tiankeng, indicating that the individuals of species increased, but the species distribution was steady.(2)The total soil nitrogen content in the outside areas of tiankeng was significantly higher than those in the top and outside areas of tiankeng. The soil total magnesium content, soil phosphorus content and soil available phosphorus content in the inside area of tiankeng were significantly higher than those in the top and outside area of tiankeng. The soil alkaline phosphatase content and soil urease activities in the outside area of tiankeng were significantly higher than those in the top and inside area of tiankeng. The soil phosphorus content in the tiankeng was higher, but the soil enzyme activities were lower.(3)The species diversity was strongly correlated with soil nutrients and soil enzyme activities. In conclusion, it can be seen that the habitats of the tiankeng have a great influence on the species diversity, soil enzyme activity and soil nutrient content distribution characteristics, and the soil available phosphorus content, soil alkaline phosphatase activity, soil moisture content, soil urease activity, soil total magnesium content and soil total phosphorus content are the key factors affecting the species diversity of woody plants in the tiankeng forest. The results provide a theoretical basis for the protection and reconstruction of plant resources in karst areas.