A Microbial Observatory in the Duke Forest: Exploring Fungal Diversity in Response to Environmental Change

在许多大规模的生态研究中，真菌的多样性及其在生态系统功能和变化中的作用几乎完全被忽视。 DNA 测序、生物信息学和系统发育分析领域的最新进展使得微生物多样性研究取得了许多进展。 正在开发一种基于分子系统学对杜克森林（北卡罗来纳州达勒姆）真菌生物多样性进行常规调查的系统。杜克森林位于北卡罗来纳州山麓高原的东部边缘附近，支持多种植物物种（超过 100 种树种）、土壤和土地利用条件，目前正在进行的研究项目包括节肢动物多样性调查、环境变化影响（包括二氧化碳升高）、不同土地利用历史以及自然演变的森林群落动态的研究。 杜克森林真菌学观测站（DFMO）将允许研究构成温带森林腐生和菌根真菌核心群的真菌群落。 作为试点项目，将对代表一系列森林类型的地块进行调查，以建立森林担子菌多样性的基线数据集。 接下来将研究几项长期研究中的地块，包括最近启动的自由空气二氧化碳富集（FACE）实验。 FACE 研究的早期数据表明土壤中微生物种群的变化，但迄今为止 FACE 尚未对微生物多样性进行调查。 菌根真菌的丰度、活性和多样性特别有可能发生变化（响应 FACE 图中根系分泌物供应量的增加），并且可能对森林/生态系统的长期健康和稳定发挥重要作用。 这项研究将开发一个与杜克森林内的地点相连的 DNA 序列数据库框架（基于核糖体 ITS 序列）。对于大多数真菌类群来说，广泛的分子数据库已经可用，使得在大多数情况下可以识别属的分离株，并且通常可以识别到物种水平。重点将放在这些地点的土壤、凋落物和菌根样本上，这将提供比基于“地上”子实体或可栽培多样性采样的估计更公正的微生物多样性估计。 这些数据将成为杜克森林和 FACE 站点内真菌微生物多样性长期监测的基础。 该项目将提供有关各种栖息地的土壤栖息、菌根、土壤和凋落物真菌的基线数据。 该项目也将是首批真菌群落结构研究之一，旨在评估各种环境变量（例如二氧化碳浓度增加对真菌多样性的影响）的影响。

In many large-scale ecological studies the diversity of fungi and their roles in ecosystem function and change are almost totally ignored. Recent advances in the fields of DNA sequencing, bioinformatics, and phylogenetic analysis have made possible many advances in studies of microbial diversity. A system for performing routine surveys of fungal biodiversity in Duke Forest (Durham, NC) based on molecular systematics is being developed. The Duke Forest lies near the eastern edge of the North Carolina piedmont plateau and supports diverse plant species (over100 tree species), soils, and land use conditions and research projects currently underway include surveys of arthropod diversity, studies of the effects of environmental change including elevated carbon dioxide, different land use histories, and the dynamics of naturally evolving forest communities. The Duke Forest Mycological Observatory (DFMO) will permit the study of those fungal communities which form the core group of saprophytic and mycorrhizal fungi in temperate forests. As a pilot project, plots representing a range of forest types will be surveyed in order to establish a baseline data set of basidiomycete diversity from the forest. Plots located within several long-term studies including the recently initiated Free-Air Carbon dioxide enrichment (FACE) experiment will next be studied. Early data from the FACE study indicate shifts in the microbial population in the soil, but as yet there have been no surveys of microbial diversity by FACE. Shifts in the abundance, activity and diversity of mycorrhizal fungi are particularly likely (in response to a greater supply of root exudates in the FACE plots) and may play an important role in long term forest/ecosystem health and stability. This study will develop a DNA-sequence database framework (based on ribosomal ITS sequences) linked with sites within the Duke Forest. Extensive molecular databases are already available for most fungal groups, making it possible to identify isolates to the genus in most instances and often to the species level. The focus will be on soil, litter and mycorrhizal samples from these sites, which will provide a more unbiased estimate of microbial diversity than estimates based 'above ground' sampling of fruit bodies or cultivable diversity. These data will then form a basis for the long term monitoring of fungal microbial diversity within the Duke Forest and FACE site. This project will provide baseline data about soil-inhabiting, mycorrhizal, soil, and litter-fungi from a variety of habitats. This project will also be one of the first studies of fungal community structure to assess the impacts of various environmental variables such as increases in carbon dioxide concentration on fungal diversity.