ABSTRACT

Soil microbes’ response to sudden environmental changes is very complicated and has been lively debated. There are a handful of questions yet to answer: are there any succession rules for different soil microbial species to fit in the suddenly changed environment? And what is the correlation between the community succession and the habitat recovery? These questions remain unanswered yet. Nematode-trapping fungi (NTF) play a very important role in the soil ecosystem and can be studied by traditional culture method easily. So, in this study, the NTF community in two burned sites at two depths (0–10 and 10–20 cm) was investigated in comparison with adjacent unburned sites. While the original NTF community structure was rather different in the two unburned sites, the NTF community presented a consistent pattern in the two burned sites: (1) considerable amount of NTF in the shallow soil (0–10 cm) was killed by the extremely high temperature of fire and the vacant niches were subsequently replaced with NTF communities that were originally distributed in the deep soil (10–20 cm); (2) dominant species in the community changed from Arthrobotrys fungi which showed stronger saprophytic ability to Dactylellina fungi which showed stronger capturing ability; and (3) the vacant niche caused by the movement of Dactylellina fungi was taken by Drechslerella fungi. The study shows that microbes inhabited in the deep soil played a critical role in the after-fire process to recovery of the soil ecological system.

摘要

土壤微生物对突然的环境变化的反应非常复杂，并进行了激烈的辩论。还有许多问题要回答：对于突然变化的环境中的土壤微生物，是否有任何继承规则？群落演替与栖息地恢复之间有什么关联？这些问题仍然没有答案。线虫诱捕真菌（NTF）在土壤生态系统中起着非常重要的作用，可以很容易地通过传统的培养方法进行研究。因此，在这项研究中，与相邻的未燃烧地点相比，研究了两个深度（0-10和10-20 cm）的两个燃烧地点的NTF群落。虽然原始的NTF社区结构在两个未烧毁的站点中有很大不同，但NTF社区在两个烧毁的站点中呈现出一致的模式：（1）极高的火势杀死了浅层土壤（0-10 cm）中相当数量的NTF，随后用原来分布在深层土壤（10-20 cm）中的NTF群落取代了空位; （2）社区优势种由节丛真菌其显示更强的腐生能力Dactylellina真菌其显示更强的捕获能力; 和（3）引起的运动的空置利基Dactylellina真菌被带到由Drechslerella真菌。研究表明，深层土壤中的微生物在后燃过程中对恢复土壤生态系统起着至关重要的作用。