PDF(Pubmed)
Abstract：
Lichens are an important part of forest ecosystems, contributing to forest biodiversity, the formation of micro-niches and nutrient cycling. Assessing the diversity of lichenised fungi in complex ecosystems, such as forests, requires time and substantial skills in collecting and identifying lichens. The completeness of inventories thus largely depends on the expertise of the collector, time available for the survey and size of the studied area. Molecular methods of surveying biodiversity hold the promise to overcome these challenges. DNA barcoding of individual lichen specimens and bulk collections is already being applied; however, eDNA methods have not yet been evaluated as a tool for lichen surveys. Here, we assess which species of lichenised fungi can be detected in eDNA swabbed from bark surfaces of living trees in central European forests. We compare our findings to an expert floristic survey carried out in the same plots about a decade earlier. In total, we studied 150 plots located in three study regions across Germany. In each plot, we took one composite sample based on six trees, belonging to the species Fagussylvatica, Piceaabies and Pinussylvestris. The eDNA method yielded 123 species, the floristic survey 87. The total number of species found with both methods was 167, of which 48% were detected only in eDNA, 26% only in the floristic survey and 26% in both methods. The eDNA contained a higher diversity of inconspicuous species. Many prevalent taxa reported in the floristic survey could not be found in the eDNA due to gaps in molecular reference databases. We conclude that, currently, eDNA has merit as a complementary tool to monitor lichen biodiversity at large scales, but cannot be used on its own. We advocate for the further development of specialised and more complete databases.
摘要：
地衣是森林生态系统的重要组成部分,促进森林生物多样性，微生态位的形成和养分循环。评估复杂生态系统中地衣真菌的多样性，比如森林,需要时间和大量的技能来收集和识别地衣。因此，库存的完整性在很大程度上取决于收藏家的专业知识，可用于调查的时间和研究区域的大小。调查生物多样性的分子方法有望克服这些挑战。已经对单个地衣标本和散装标本进行了DNA条形码编码；但是，eDNA方法尚未被评估为地衣调查的工具。这里,我们评估了从中欧森林中活树的树皮表面擦拭的eDNA中可以检测到哪些种类的苔藓真菌。我们将我们的发现与大约十年前在同一地块进行的专家植物区系调查进行了比较。总的来说,我们研究了位于德国三个研究区的150个地块。在每个情节中，我们根据六棵树采集了一个复合样本，属于Fagussylvatica物种，比色树和比色树。eDNA方法产生了123个物种，植物区系调查87.两种方法发现的物种总数为167，其中48％仅在eDNA中检测到，仅在植物区系调查中占26％，在两种方法中均占26％。eDNA包含更多不显眼的物种。由于分子参考数据库中的空白，在eDNA中找不到植物区系调查中报道的许多流行分类群。我们的结论是，目前,eDNA作为大规模监测地衣生物多样性的补充工具，但不能单独使用。我们主张进一步发展专业和更完整的数据库。
