海南鹦哥岭不同海拔热带山地雨林土壤微生物群落多样性差异

Soil Microbial Community Diversity under Different Altitudes in the Tropical Mountain Rainforests of Yinggeling National Nature Reserve in Hainan Island

土壤微生物作为土壤生态系统的重要组成部分,是自然生态系统重要的分解者,在生态系统的物质循环和能量转化中占有重要的地位,同时在维持陆地生态系统的结构和稳定其功能等诸多方面都发挥十分重要的作用。本研究以鹦哥岭不同海拔热带山地雨林的8个固定样地为实验样地,采用Biolog-ECO法,探讨了不同海拔梯度下的土壤微生物群落多样性变化特征。结果表明:部分海拔样地的土壤和凋落物的理化性质、土壤酶活性差异显著,且南坡和北坡不同。反映土壤微生物活性的AWCD值的大小顺序为:YGL22 (591 m) > YGL32 (550 m) > YGL23 (458 m) > YGL21 (745 m) > YGL18 (1025 m) > YGL24 (800 m) > YGL16 (1355 m) > YGL34 (406 m);南坡745 m海拔处样地土壤微生物群落对碳源的利用模式为理论模式I,南坡1025 m、1355 m与北坡458 m、800 m海拔处样地土壤微生物群落对碳源的利用模式为理论模式II,南坡406 m、550 m和北坡591 m海拔处样地土壤微生物群落对碳源的利用模式为理论模式III。土壤微生物群落功能多样性指数随海拔的升高先增加后减少,符合“中峰分布”格局。土壤微生物碳源代谢多样性的垂直地带性差异主要体现在碳水化合物、多聚物类和羧酸类碳源的利用,土壤微生物群落功能多样性与土壤有效磷含量显著正相关(p < 0.05),与土壤酸性磷酸酶、凋落物有机碳含量显著负相关(p < 0.05),与土壤过氧化氢酶显著负相关(p < 0.05)。土壤有效磷、酸性磷酸酶、过氧化氢酶和凋落物有机碳含量可能是导致鹦哥岭热带山地雨林土壤微生物群落功能多样性的海拔分布异质性的重要影响因子,研究结果为进一步探讨热带山地雨林与土壤微生物之间的关系奠定了基础。

Soil microbes are an important component of soil ecosystem and playing a key role in nutrient and energy cycling. At the same time, it plays a very important role in maintaining the structure and stabilizing the functions of terrestrial ecosystems. This study used 8 fixed plots of tropical mountain rainforests at different altitudes in Yinggeling as experimental plots, and used the BIOLOG- ECO method to explore the variation of soil microbial community diversity under different altitude gradients. The results showed that three were significant differences in the physicochemical properties and soil enzyme activities of soil and litter in some altitude plots, and the south and north slopes were different. The order of AWCD values reflecting soil microbial activity was YGL22 (591 m) > YGL32 (550 m) > YGL23 (458 m) > YGL21 (745 m) > YGL18 (1025 m) > YGL24 (800 m) > YGL16 (1355 m) > YGL34 (406 m);the utilization mode of soil microbial communities on carbon sources at elevations of 745 m on the south slope was the theoretical mode I, 1025 m and 1355 m on the south slope, 458 m and 800 m on the north slope were the theoretical mode II, 406 m and 550 m on the south slope and 591 m on the north slope were the theoretical mode III. The functional diversity index of soil microbial community increased first and then decreased with the increase of altitude, which conformed to the pattern of “Middle Peak Distribution”, and the vertical zonal differences in the metabolic diversity of soil microbial carbon sources were mainly reflected in the utilization of carbohydrates, polymers and carboxylic acids. The functional diversity of soil microbial community was significantly positively correlated with soil available phosphorus content (p < 0.05), negatively correlated with soil acid phosphatase and litter organic carbon content (p < 0.05), and highly negatively correlated with soil catalase (p < 0.01). The soil available phosphorus, acid phosphatase, catalase and organic carbon content of litter may be the important influencing factors for the altitude distribution heterogeneity of soil microbial community functional diversity in the Yinggeling tropical mountain rainforest. The results of this study suggested a basis for further investigation of the relationships between tropical mountain rainforests and soil microbial community diversity.