Data from: Host-specific effects of soil microbial filtrates prevail over those of arbuscular mycorrhizae in a fragmented landscape

Plant-soil interactions have been shown to determine plant community composition in a wide range of environments. However, how plants distinctly interact with beneficial and detrimental organisms across mosaic landscapes containing fragmented habitats is still poorly understood. We experimentally tested feedback responses between plants and soil microbial communities from adjacent habitats across a disturbance gradient within a human-modified tropical montane landscape. In a greenhouse experiment, two components of soil microbial communities were amplified; arbuscular mycorrhizal fungi (AMF) and a filtrate excluding AMF spores from the soils of pastures (high disturbance), coffee plantations (intermediate disturbance), and forest fragments (low disturbance), using potted seedlings of 11 plant species common in these habitats (pasture grass, coffee, and 9 native species). We then examined their effects on growth of these same 11 host species with reciprocal habitat inoculation. Most plant species received a similar benefit from AMF, but differed in their response to the filtrates from the three habitats. Soil filtrate from pastures had a net negative effect on plant growth, while filtrates from coffee plantations and forests had a net positive effect on plant growth. Pasture grass, coffee and five pioneer tree species performed better with the filtrate from “away” (where these species rarely occur) compared to “home” (where these species typically occur) habitat soils, while four shade tolerant tree species grew similarly with filtrates from different habitats. These results suggest that pastures accumulate species-specific soil enemies, while coffee plantations and forests accumulate beneficial soil microbes that benefit pioneer native plants and coffee, respectively. Thus, compared to AMF, soil filtrates exerted stronger habitat and host-specific effects on plants, being more important mediators of plant-soil feedbacks across contrasting habitats.

大量研究已证实，植物-土壤互作（plant-soil interactions）可决定多种生境下的植物群落组成。然而，在包含破碎化生境的镶嵌景观中，植物如何与有益、有害生物产生差异化互作，目前仍未得到充分阐释。本研究在受人类活动改造的热带山地景观中，沿干扰梯度选取相邻生境的土壤微生物群落，通过实验探究植物与该类群落间的反馈响应。在温室实验中，研究人员针对三类生境（牧场：高干扰；咖啡种植园：中干扰；森林片段：低干扰）的土壤，制备得到两类土壤微生物群落组分：丛枝菌根真菌（arbuscular mycorrhizal fungi, AMF），以及去除AMF孢子的土壤滤液；实验所用的接种宿主为11种常见于上述生境的盆栽幼苗，涵盖牧场草本、咖啡作物以及9种本土植物。随后通过跨生境反向接种实验，检测这两类微生物组分对上述11种宿主植物生长的影响。多数植物物种从AMF中获得的生长收益相近，但对三类生境来源的土壤滤液的响应则存在显著差异。牧场来源的土壤滤液对植物生长呈现净负面效应，而咖啡种植园与森林来源的滤液则呈现净正面效应。牧场草本、咖啡作物以及5种先锋乔木物种，在接种“异地生境（即该类植物极少分布的生境）”来源的滤液时，生长表现优于接种“本土生境（即该类植物常规分布的生境）”来源的滤液；而4种耐阴乔木物种在接种不同生境来源的滤液时，生长表现无显著差异。上述结果表明，牧场会积累物种特异性的土壤有害生物，而咖啡种植园与森林则分别积累有益于先锋本土植物与咖啡作物的有益土壤微生物。综上，相较于AMF，土壤滤液对植物产生的生境特异性与宿主特异性效应更强，是不同生境间植物-土壤反馈的更关键调控因子。