Woody species encroachment of grasslands globally causes many socioecological impacts, including loss of grazing pastures and decreased biodiversity. Soil microbial communities may partially regulate the pace of shrub encroachment, as plant-microbial interactions can strongly influence plant success. We measured fungal composition and activity under dominant plant species across a grassland to shrubland transition to determine if shrubs cultivate soil microbial communities as they invade. Specifically, soil microbial communities, abiotic soil properties, and extracellular enzyme activities were quantified for soils under four common Chihuahuan Desert plant species (three grasses, one shrub) in central New Mexico, U.S.A. Extracellular enzyme activity levels were fairly consistent under different plant species across the grassland to shrubland transition. Activity levels of two enzymes (alkaline phosphatase and beta-N-acetyl-glucosaminidase) were lower in the ecotone, presumably because soil organic matter content was also lower in ecotone soils. Community composition of soil fungi mirrored patterns in the plant community, with distinct plant and fungal communities in the shrubland and grassland, while grassland-shrubland ecotone soils hosted a mix of taxa from both habitats. We show that shrubs cultivate a distinct microbial community on the leading edge of the invasion, which may be necessary for shrub colonization, establishment, and persistence.

全球范围内木本物种对草原的侵占造成了许多社会生态影响，包括放牧牧场的丧失和生物多样性的减少。土壤微生物群落可能部分调节灌木侵占的速度，因为植物与微生物的相互作用可以强烈影响植物的成功。我们测量了草原到灌木地过渡的优势植物物种下的真菌组成和活性，以确定灌木在入侵时是否培养土壤微生物群落。具体而言，量化了美国新墨西哥州中部四种常见的奇瓦瓦沙漠植物物种（三种草，一种灌木）下土壤的土壤微生物群落、非生物土壤特性和细胞外酶活性 在不同植物物种下，草地向灌木地过渡的细胞外酶活性水平相当一致。两种酶（碱性磷酸酶和β-N-乙酰氨基葡萄糖苷酶）的活性水平在交错带中较低，可能是因为在交错带土壤中土壤有机质含量也较低。土壤真菌的群落组成反映了植物群落的模式，在灌丛和草地具有不同的植物和真菌群落，而草地-灌丛交错带土壤则是来自两个生境的混合分类群。我们表明灌木在入侵的前缘培养了一个独特的微生物群落，这可能是灌木定植、建立和持久所必需的。两种酶（碱性磷酸酶和β-N-乙酰氨基葡萄糖苷酶）的活性水平在交错带中较低，可能是因为在交错带土壤中土壤有机质含量也较低。土壤真菌的群落组成反映了植物群落的模式，在灌丛和草地具有不同的植物和真菌群落，而草地-灌丛交错带土壤则是来自两个生境的混合分类群。我们表明灌木在入侵的前缘培养了一个独特的微生物群落，这可能是灌木定植、建立和持久所必需的。两种酶（碱性磷酸酶和β-N-乙酰氨基葡萄糖苷酶）的活性水平在交错带中较低，可能是因为在交错带土壤中土壤有机质含量也较低。土壤真菌的群落组成反映了植物群落的模式，在灌丛和草地具有不同的植物和真菌群落，而草地-灌丛交错带土壤则是来自两个生境的混合分类群。我们表明灌木在入侵的前缘培养了一个独特的微生物群落，这可能是灌木定植、建立和持久所必需的。而草原-灌木林交错带土壤则是来自两个栖息地的混合分类群。我们表明灌木在入侵的前缘培养了一个独特的微生物群落，这可能是灌木定植、建立和持久所必需的。而草原-灌木林交错带土壤则是来自两个栖息地的混合分类群。我们表明灌木在入侵的前缘培养了一个独特的微生物群落，这可能是灌木定植、建立和持久所必需的。