Controls Over Fungal Communities and Consequences for Nutrient Cycling

土壤中蕴藏着令人难以置信的微生物多样性-例如，阿拉斯加森林的一平方米可以居住数百种真菌，其中大多数尚未命名。是什么控制了土壤中真菌的多样性？不同的物种有不同的功能吗？科学家们对发掘这些问题很感兴趣，因为真菌可以分解动植物的死亡组织。在此过程中，它们向大气中释放二氧化碳（一种温室气体）。如果不同的物种针对死亡物质的不同成分，那么更多样化的真菌群落可能会向大气中释放更多的二氧化碳。Treseder，Borneman和Mack将研究真菌群功能的变化和它们分解的凋落物的化学变化都是真菌多样性的重要控制因素的假设，并且真菌多样性的变化可能会影响CO2的产生。他们将使用最近开发的DNA技术（核苷酸类似物）来鉴定在阿拉斯加森林中不同类型的分解树叶上发现的单个真菌群的功能。他们还将建立具有不同数量真菌群的微型实验室生态系统，然后测量这些生态系统内的分解率。这项工作的科学意义将是更好地了解生态系统地下发生的过程，并提高预测生态系统如何应对环境变化的能力。所获得的信息应有助于确定面对全球变化的政策建议。

Soils harbor an incredible diversity of microbes-- for example, one square meter of Alaskan forest can be inhabited by hundreds of species of fungi, most of which have not yet been named. What controls the diversity of fungi in the soil? Do different species perform different functions? Scientists are interested in unearthing these questions because fungi decompose dead tissues from plants and animals. In doing so, they release CO2 (a greenhouse gas) to the atmosphere. If different species target different components of dead material, a more diverse community of fungi may release more CO2 to the atmosphere. Treseder, Borneman, and Mack will examine the hypotheses that variation in functions of fungal groups and variation in the chemistry of the litter they decompose are both important controls over the diversity of fungi, and that changes in fungal diversity may influence CO2 production. They will use a recently developed DNA technique (nucleotide analogs) to identify the functions of individual groups of fungi found on different types of decomposing leaves in Alaskan forests. They will also establish miniature laboratory ecosystems with varying numbers of fungal groups, and then measure decomposition rates within those ecosystems.The scientific importance of this work will be a better understanding of the processes that occur belowground in ecosystems, and an increased capacity to predict how ecosystems will respond to changes in the environment. The information gained should be useful in determining policy recommendations in the face of global change.