Trophic interactions and ecological functions of ants under changing tree diversity

树木多样性变化下蚂蚁的营养相互作用和生态功能

• 批准号: 498261743
• 负责人: Professorin Dr. Heike Feldhaar
• 金额: --
• 依托单位: Arbeitsgruppe Ecological Networks
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/498261743?language=en
• 关键词: Trophic; interactions; ecological; functions; ants

Wider research context: Plant diversity relates to consumer diversity across trophic levels, but only few studies investigated in forests how producer (i.e. tree) diversity influences multitrophic interactions and ecosystem functions of arthropods. Unravelling the relationship between tree diversity and trophic interactions is crucial to understand biodiversity-ecosystem functioning relationships, which are often the outcome of interactions involving arthropods. Occurring in several trophic levels, from phytophagous to highly predacious, with most species being omnivores, ants are ideal for studying multitrophic interactions.Hypotheses: In line with preliminary results, we hypothesize that ant species diversity increases with tree diversity. Following the enemies hypothesis, we hypothesize that the degree of ant predatory life style increases with tree diversity and that functional morphospace shifts towards relatively more predacious communities. Alongside, we expect higher generality and redundancy in resource choice when tree diversity and, thus, ant diversity is high. These tree diversity-mediated changes in trophic interactions relate to realized trophic niches, with higher species-level δ15N indicating a larger share of animal-derived food objects and with broader community isotopic niche breadth indicating trophic redundancy. We hypothesise that the function ‘scavenging’ increases with tree diversity, which is mechanistically related to ant diversity and trait distribution as well as trophic positions, that are all mediated by tree diversity.Methods: In all core plots, we will quantify ant diversity and trait distribution to functionally characterise all collected species. To identify the trophic position of individual species and the entire ant community and to quantify trophic niche breadth and trophic redundancy, we will perform resource-choice experiments and measure δ15N isotope values. We will also test which traits relate to trophic niche breadth and relative trophic position. To link ant diversity and trophic interactions to an ecosystem function, we will measure ‘scavenging’ as the retrieval rate of standard carrion baits in the VIP plots.Innovation: Ants have, with the exception of our initial work, only rarely been studied in tree diversity experiments. By integrating across components of biological organization in a key arthropod taxon we will reveal how the interplay among tree diversity, ant diversity, trait distribution and trophic interactions influences forest ecosystem functionality. Our data will allow predicting if ant diversity decreases in simplified ecosystems and how ant-mediated functions depend on diversity and interactions across trophic levels.Primary researchers involved: This project will be conducted by Michael Staab (PI, Darmstadt) and Heike Feldhaar (Co-PI, Bayreuth), in collaboration with our Chinese partner Xiaojuan Liu (Beijing).

更广泛的研究背景：植物多样性与营养层次上的消费者多样性有关，但很少有研究在森林中调查生产者(即树木)多样性如何影响节肢动物的多营养相互作用和生态系统功能。揭示树木多样性和营养相互作用之间的关系对于理解生物多样性-生态系统功能关系至关重要，这种关系通常是节肢动物相互作用的结果。蚂蚁存在于从植食性到高度捕食性的几个营养级别，其中大多数物种是杂食性动物，是研究多营养相互作用的理想物种。假设：根据初步结果，我们假设蚂蚁物种多样性随着树木多样性的增加而增加。根据敌人假说，我们假设蚂蚁捕食性生活方式的程度随着树木多样性的增加而增加，功能形态空间向相对更具捕食性的群落转移。此外，当树木多样性和蚂蚁多样性较高时，我们期望资源选择具有更高的通用性和冗余性。这些由树木多样性介导的营养相互作用的变化与已实现的营养生态位有关，物种水平较高的δ15N表明动物来源的食物对象所占份额较大，而较宽的群落同位素生态位宽度表明营养过剩。我们假设清除功能随着树木多样性的增加而增加，这与蚂蚁多样性和特征分布以及营养位置有关，这都是由树木多样性所中介的。方法：在所有核心地块中，我们将量化蚂蚁多样性和特征分布，以确定所有收集到的物种的功能特征。为了确定单个物种和整个蚂蚁群落的营养位置，并量化营养生态位宽度和营养冗余度，我们将进行资源选择实验和测量δ15N同位素值。我们还将测试哪些性状与营养生态位宽度和相对营养位置有关。为了将蚂蚁的多样性和营养相互作用与生态系统功能联系起来，我们将在VIP图中测量标准腐肉诱饵的取回率来衡量“清除”。创新：除了我们最初的工作外，很少有人在树木多样性实验中对蚂蚁进行研究。通过整合关键节肢动物分类群中生物组织的各个组成部分，我们将揭示树木多样性、蚂蚁多样性、特征分布和营养相互作用之间的相互作用如何影响森林生态系统功能。我们的数据将允许预测简化生态系统中蚂蚁多样性是否减少，以及蚂蚁介导的功能如何依赖于多样性和营养水平之间的相互作用。主要研究人员参与：该项目将由Michael Staab(Pi，Darmstadt)和Heike Feldhaar(Co-Pi，Bayreuth)与我们的中国合作伙伴刘晓娟(北京)合作进行。