Inoculation with remnant prairie soils increased the growth of three native prairie legumes but not necessarily their associations with beneficial soil microbes
Inoculation with remnant prairie soils increased the growth of three native prairie legumes but not necessarily their associations with beneficial soil microbes
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DOI：
10.1111/rec.13126
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发表时间：
2020-02-23
影响因子：
3.2
通讯作者：
Price, Paul A.
中科院分区：
文献类型：
--
作者：
Grman, Emily;Allen, Jamie;Price, Paul A.
恢复残余群落中发现的植物物种的多样性对恢复从业者来说是一个挑战，部分原因是许多重新引入的植物物种未能在恢复的地点建立。豆科植物的生长特别差，可能是因为它们依赖于两种土壤微生物共生菌——根瘤菌和丛枝菌根（AM）真菌，而这两种真菌在恢复的地点可能不存在。以美国密歇根州西南部10个恢复草原和6个未开垦草原为土壤样本，接种胡枝子（lepedeza capitata）、紫穗槐（Amorpha canescens）和紫花苜蓿（Dalea purpurea）幼苗，研究了残留草原和恢复草原土壤微生物对豆科植物生长的影响。我们普遍发现，恢复的草原土壤缺乏促进草原植物生长的微生物这一假设得到了支持，尽管物种和互惠协会之间存在差异。与残存草原土壤接种后，3种豆科植物均生长较大，其中2种豆科植物（胡枝子和紫穗槐）的根瘤菌数量和质量较低，可能限制了这些物种在恢复草原上的建立。相比之下，没有豆科植物在剩余草原土壤中受到AM真菌的根定植，这表明真菌伴侣在剩余和恢复的草原土壤中数量相等（但不一定是质量相等）。我们没有发现在修复过程中有益土壤微生物群落自发恢复的证据。这些结果表明，根瘤菌是草原土壤中一个很大程度上被忽视的组成部分，根瘤菌的缺乏可能通过阻碍豆科植物的建立而在限制恢复的草原多样性方面发挥重要作用。主动重新引入适当的根瘤菌菌株可以提高草原恢复的效果。
Restoring the diversity of plant species found in remnant communities is a challenge for restoration practitioners, in part because many reintroduced plant species fail to establish in restored sites. Legumes establish particularly poorly, perhaps because they depend on two guilds of soil microbial mutualists, rhizobial bacteria and arbuscular mycorrhizal (AM) fungi, that may be absent from restored sites. We tested the effect of soil microorganisms from remnant and restored prairies on legume growth by inoculating seedlings of Lespedeza capitata, Amorpha canescens, and Dalea purpurea with soil from 10 restored prairies and 6 remnant (untilled) prairies from southwest Michigan. We generally found support for the hypothesis that restored prairie soils lack microbes that enhance prairie plant growth, although there was variation across species and mutualist guilds. All three legumes grew larger and two legumes (Lespedeza and Amorpha) produced more nodules when inoculated with soil from remnant prairies, suggesting that low quantity and/or quality of rhizobial partners may limit the establishment of those species in restored prairies. In contrast, no legume experienced greater root colonization by AM fungi in remnant prairie soils, suggesting equivalent quantity (but not necessarily quality) of fungal partners in remnant and restored prairie soils. We detected no evidence of spontaneous recovery of the community of beneficial soil microbes in restorations. These results suggest that the absence of rhizobia, a largely overlooked component of prairie soils, could play a strong role in limiting restored prairie diversity by hindering legume establishment. Active reintroduction of appropriate rhizobial strains could enhance prairie restoration outcomes.