The effect of tree species diversity on foliar fungal pathogens

树种多样性对叶面真菌病原菌的影响

• 批准号: 251261869
• 负责人: Dr. Lydia Hönig
• 金额: --
• 依托单位: Herbarium
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/251261869?language=en
• 关键词: effect; tree; species; diversity; foliar

Foliar fungal pathogens affect ecosystem processes in forests through highly speciesspecific effects of trees on growth and survival. Thus, fungal pathogens can contribute to maintain tree diversity. As host-specialized pathogenic organisms such as foliar fungal pathogens are both response to and effect of tree diversity in forests, both can be disentangled with the experimental design of BEF-China. In my subproject I aim to test the hypotheses: (1) Tree species diversity decreases disease risk and pathogen load of pathogenic fungi on a particular host species because host species density and thus, fungal habitat availability, is diluted with increasing tree species diversity. (2) Tree species diversity increases foliar fungal species diversity. (3) The phylogenetic similarity of host species increases the phylogenetic similarity of foliar fungal communities on different tree species, as a consequence of the co-evolution of the pathogens with their hosts. (4) The degree of herbivory leads to increased fungal pathogen load. (5) Increasing pathogen load decreases the growth and the fitness of tree individuals and species. I will address these hypotheses with three different experimental set ups of the BEF-China project. WP1 will quantify pathogen load as percentage of leaf area infected by foliar fungal pathogens across all tree species in all plots of the Main Experiment. WP2 will identify for a total of 16 selected tree species all fungus species that occur on leaves of a certain tree species and construct tree species-specific phylogenies and trophobiotic networks. This work package will be complemented by molecular identification of fungi by the Chinese partner project of Jiye Yan, who will also construct molecular fungal phylogenies. WP3 will assess the effect of foliar fungal pathogens on plant performance in the BEFmod approach as well as the effects of P fertilization, competition of the herb layer and herbivory on pathogen load (in particular with SP1, 2, 8, 9, 11). Combining information from the two observational levels and the experimental approach of BEFmod will allow me to address one of the key questions in functional biodiversity research: how pathogens mediate plant species richness-growth relationships in response to herbivory and tree species loss with a focus on trophobiotic interactions.

叶面真菌病原体通过对树木生长和存活的高度物种特异性影响来影响森林生态系统过程。因此，真菌病原体可以有助于维持树木的多样性。由于寄主专化性病原生物（如叶部真菌病原体）既是对森林树木多样性的响应，也是其影响，因此两者都可以通过BEF-中国的实验设计来解开。在我的子项目中，我的目标是测试的假设：（1）树种多样性降低疾病的风险和病原体负载的病原真菌对特定的主机种，因为主机种密度，从而真菌栖息地的可用性，稀释与增加树种多样性。(2)树种多样性增加了叶真菌物种多样性。(3)寄主物种的系统发育相似性增加了不同树种叶面真菌群落的系统发育相似性，这是病原菌与寄主共同进化的结果。(4)草食性程度导致真菌病原菌负荷增加。(5)病原菌负荷的增加降低了树木个体和物种的生长和适合度。我将通过BEF-China项目的三个不同的实验设置来解决这些假设。WP 1将在主要实验的所有地块中，将病原体负荷量化为所有树种中被叶面真菌病原体感染的叶面积的百分比。WP 2将确定总共16个选定树种的所有真菌物种，出现在某一树种的叶子上，并构建树种特异性的共生和营养生物网络。这项工作包将由中国合作伙伴严继业的真菌分子鉴定项目补充，他还将构建分子真菌遗传学。WP 3将评估叶面真菌病原体对BEFmod方法中植物性能的影响，以及磷肥、草本层竞争和食草动物对病原体负荷的影响（特别是SP1、2、8、9、11）。从两个观测水平和BEFmod的实验方法相结合的信息将使我能够解决功能性生物多样性研究中的一个关键问题：病原体如何介导植物物种丰富度的增长关系，以响应草食动物和树种的损失，重点是营养生物相互作用。