Differences of Moss Mites Communities at Different Vegetation Succession Stages in Subalpine Wetland (Jiulongchi, Fanjing Mountain), Southwest China

Abstract

Fanjing Mountain, China, is a World Man and Biosphere Reserve, a World Natural Heritage Property, and a Nature Reserve in China. Mites communities have been reported from the Fanjing Mountain. Wetland moss microhabitats provide a unique habitat for mites, and our objective is to document moss mites communities in the subalpine wetlands of Fanjing Mountain (Jiulongchi), with a particular focus on trends in moss mites at different stages of vegetation succession in the wetlands, which have rarely been described, and the research will provide fundamental data for biodiversity conservation in the face of global climate change. The succession sequence from bryophyte (hygrophyte) to shrub (mesophyte or xerophyte) in the open area of Jiulongchi wetland successively includes Polytrichum commune Hedw. (PC), Eleocharis yokoscensis (Franch. et Sav.) Tang et-Cypers sp. (EY-C), Senecio faberii Hemsl (SF), and Indocalamus longiauritus Hand.-Mazz. (IL) four typical communities. In April 2016, we collected moss samples under the four typical communities mentioned above, and analyzed the difference of moss mite communities using PCA, Kruskal–Wallis nonparametric test, and ANOVA. The results showed the following: (1) A total of 9058 moss mites belonging to 49 genera in 3 orders and 69 families were captured in the four plant communities, with the moss mites Parachipteria, Fuscozetes, and Tectocepheus being the dominant taxa of moss mites in Jiulongchi wetland. The core taxa of moss mites at different successional stages were 12 genera, with IL having the largest number of exclusive taxa (20 genera). (2) The abundance of moss mites showed an overall increasing trend from PC to IL habitats, with the number of families and genera showing a pattern of IL > EY-C > SF > PC. The diversity index SF habitat possessed the maximum value, followed by IL, both of which were significantly different from PC. (3) The results of PCA analysis of moss mites showed that the mite community composition of PC habitats differed more from SF and IL, respectively, and less from EY-C. (4) There existed differences in the ecological taxa of predatory moss mites at different successional stages, with the Poronota group dominating the ecological taxa of oribatida. The research indicated that moss mites communities in subalpine wetlands were rich in species composition, and with the succession of vegetation from hygrophyte to mesophyte or xerophyte, the moss mites group as a whole develops in a direction favorable to its diversity, and the differences in moss mites ecological taxa also demonstrated the variability and complexity of the Jiulongchi wetland environment. This research presents the distribution pattern of moss mites in different vegetation succession stages in subtropical subalpine herbaceous wetlands. The moss mites evolution trend in response to climate-change-induced plant community succession needs further investigation.