Habitat edge effects can have profound impacts on biodiversity throughout terrestrial and aquatic biomes. Yet, few studies have examined how habitat edge effects impact the spatial patterning of sediment properties and microbial communities, especially in coastal ecosystems. Coastal salt marshes throughout the world are being transformed by sea level rise; high-marsh, flood-intolerant species, such as Spartina patens, are being fragmented and replaced by low-marsh, flood-tolerant species, such as Spartina alterniflora. The consequences of these habitat transformations on fungal communities remain unclear. Thus, we sought to identify how habitat edge effects, alongside changing plant community dynamics, impact the spatial patterning of fungal communities associated with ubiquitous Spartina species. We analyzed 26 Spartina patens patches: 13 pure monocultures and 13 mixed patches with Spartina alterniflora infiltration. We measured patch characteristics, plant characteristics, sediment physicochemical properties, and sediment fungal communities. We found that habitat edge effects structured sediment and plant properties in both pure and mixed patches. However, habitat edge effects only structured fungal community composition in mixed patches, counter to expectations. These results indicate that changing plant community dynamics driven by sea level rise can exacerbate habitat edge effects in coastal ecosystems. Least discriminant analysis and co-occurrence networks further revealed unique taxa and network structures between pure and mixed patches and between interiors and edges. In sum, we found that habitat transformation of coastal salt marshes driven by global change impacts the spatial dynamics of sediment and fungal properties.

栖息地边缘效应会对整个陆地和水生生物群落的生物多样性产生深远的影响。然而，很少有研究探讨栖息地边缘效应如何影响沉积物特性和微生物群落的空间格局，特别是在沿海生态系统中。世界各地的沿海盐沼正在因海平面上升而发生变化；高沼泽、不耐洪水的物种，如大米草，正在被破碎并被低沼泽、耐洪水的物种，如互花米草取代。这些栖息地转变对真菌群落的影响仍不清楚。因此，我们试图确定栖息地边缘效应以及不断变化的植物群落动态如何影响与普遍存在的大米草物种相关的真菌群落的空间格局。我们分析了 26 个大米草斑块：13 个纯单一栽培斑块和 13 个有互花米草渗透的混合斑块。我们测量了斑块特征、植物特征、沉积物理化特性​​和沉积物真菌群落。我们发现栖息地边缘会影响纯斑块和混合斑块中的结构化沉积物和植物特性。然而，栖息地边缘仅影响混合斑块中的结构化真菌群落组成，这与预期相反。这些结果表明，海平面上升驱动的植物群落动态变化可能会加剧沿海生态系统的栖息地边缘效应。最小判别分析和共现网络进一步揭示了纯斑块和混合斑块之间以及内部和边缘之间独特的分类单元和网络结构。总之，我们发现全球变化驱动的沿海盐沼生境转变影响沉积物和真菌特性的空间动态。