Soil Microbial Assemblages Are Linked to Plant Community Composition and Contribute to Ecosystem Services on Urban Green Roofs
Soil Microbial Assemblages Are Linked to Plant Community Composition and Contribute to Ecosystem Services on Urban Green Roofs
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DOI：
10.3389/fevo.2019.00198
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发表时间：
2019-06-11
影响因子：
3
通讯作者：
McGuire, Krista L.
中科院分区：
文献类型：
--
作者：
Hoch, Jessica M. K.;Rhodes, Matthew E.;McGuire, Krista L.
绿色屋顶是城市缓解热浪和干旱等环境压力的一种方式。然而，这些环境压力因素可能会对绿色屋顶植被产生不利影响，对植物生长和存活造成挑战，并随后降低绿色屋顶系统提供关键生态系统服务的能力，例如减缓热量和养分循环。与植物相关的微生物可以促进绿色屋顶植被对气候相关胁迫的恢复力和耐受性。然而，尽管它们在自然生态系统中对植物生长和生存起着至关重要的作用，但对绿色屋顶系统中植物相关微生物的研究却很少。在绿色屋顶上的植物选择也可以决定在绿色屋顶生长介质中建立的微生物，并且特定的植物-微生物组合可能对环境压力更具弹性。该项目旨在表征纽约市不同植物调色板的绿色屋顶上的土壤微生物群落组成，并评估绿色屋顶植物物种和根相关微生物组合的不同组合如何对隔离和同时进行的高温和干旱处理作出反应。我们调查了绿色屋顶种植景天属植物或混合植被调色板（即，野花、草和多肉植物）。我们发现，混合植被和景天属绿色屋顶有不同的土壤细菌和真菌群落（p < 0.0001），具有较高的相对丰度的菌根真菌混合植被屋顶，和更高的病原菌负载的景天属屋顶。同时，我们进行了一个温室实验，其中植物生长的种子与活接种物收集从两种不同类型的植被上的绿色屋顶，我们调查。我们观察到，植物种类，土壤接种物，和非生物胁迫处理与土壤真菌群落的变化。研究表明，绿色屋顶上的土壤微生物群落与屋顶植被有关，它们可能有助于绿色屋顶植物对环境胁迫的耐受性和恢复力。
Green roofs are a way for cities to mitigate environmental stressors, such as heatwaves and droughts. However, these environmental stressors can adversely affect green roof vegetation, causing challenges for plant growth and survival and subsequently reducing the ability of green roof systems to deliver critical ecosystem services, such as heat mitigation and nutrient cycling. Plant-associated microbes may facilitate the resilience and tolerance of green roof vegetation to climate-associated stress. However, despite their crucial role in plant growth and survival in natural ecosystems, there has been little research on plant-associated microbes in green roof systems. Plant choice on green roofs may also determine which microbes established in green roof growing media, and particular plant-microbial combinations may be more resilient to environmental stress. This project sought to characterize soil microbial community composition on green roofs across New York City with different plant palettes and assess how different combinations of green roof plant species and root-associated microbial assemblages responded to isolated and simultaneous heat and drought treatments. We surveyed green roofs planted with either Sedum species or with a mixed-vegetation palette (i.e., wildflowers, grasses, and succulents). We found that mixed-vegetation and Sedum green roofs had distinct soil bacterial and fungal communities (p < 0.0001) with a higher relative abundance of mycorrhizal fungi on mixed-vegetation roofs, and higher pathogen loads on Sedum roofs. Concurrently, we conducted a greenhouse experiment in which plants were grown from seed with live inocula collected from the two different types of vegetation on the green roofs we surveyed. We observed that plant species, soil inoculum, and abiotic stress treatment was correlated with shifts in soil fungal communities. This study demonstrated that soil microbial assemblages on green roofs are linked to the roof vegetation, and that they may facilitate green roof plants' tolerance and resilience to environmental stressors.