我国西北荒漠地区地衣分布格局及其群落构建机制

我国荒漠化日趋严重，已占国土面积的27.5%，尤其是西北低降水量地区。按照植被演替规律，低降水量地区以地衣为主的微型生物结皮是阻止荒漠化和荒漠治理的重要途径。但目前对该地区地衣分布格局及群落构建机制尚缺乏认识。因此，本项申请针对我国西北荒漠地区，以微型生物结皮中的地衣为研究对象，通过系统采集地衣结皮样本，结合多相分类技术鉴定地衣物种并分析其多样性，阐明该地区地衣物种组成及其分布格局；对地衣体、地衣结皮和结皮土壤进行高通量测序，并与地衣多样性进行关联分析，明确生物因子对地衣分布格局及群落构建的贡献；通过地衣多样性与土壤理化性质、环境因子及气候因子等非生物因素相关性分析，明确非生物因子对地衣分布格局及群落构建的影响。最终揭示我国西北荒漠地区地衣分布格局及其群落构建机制。研究结果不仅丰富对我国西北荒漠地衣多样性认识，而且，地衣群落构建机制为应用地衣开展干旱荒漠的治理及生态恢复提供理论依据。

Desertification in China is becoming increasingly serious, accounting for 27.5% of the country's land area, especially in the low rainfall areas of the Northwest. According to the law of vegetation succession, lichen-dominated microbiotic crusts are an important way to prevent and control desertification in low rainfall areas. However, the lichen distribution pattern and community assembly mechanism in this area are still lack of understanding. Therefore, the aims of current proposal are focusing on the Northwest desert of China 1) to clarify lichen species composition and distribution pattern by polyphasic taxonomy and analysis of diversity; 2) to identify the contribution of biotic factors to lichen distribution pattern and community assembly by high-throughput sequencing on lichen thallus, lichen-dominated crust and the soil beneath and correlation analysis with lichen diversity; 3) to identify the effects of abiotic factors on lichen distribution pattern and community assembly by correlation analysis between lichen diversity and abiotic factors such as soil physical and chemical properties, environmental factors, and climatic factors. Based on the above studies, the distribution pattern and community assembly mechanism of lichens in the Northwest deserts of China are finally revealed. The results will not only enrich the understanding of lichen diversity in Northwest deserts of China, but also provide theoretical basis for the application of lichen for the arid deserts control and ecological restoration.