Effects of landscape complexity on the functional diversity of natural enemies and the ecosystem service of pest control

景观复杂性对天敌功能多样性及害虫防治生态系统服务的影响

• 批准号: RGPIN-2020-06473
• 负责人: Costamagna, Alejandro
• 金额: $ 2.04万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=753214
• 关键词: Effects; landscape; complexity; functional; diversity

The relationship between biodiversity and ecosystem functioning (BEF) is central to our understanding of community ecology. Ecosystem services such as pest control (i.e. ecosystem functions that benefits humans) are crucial to ensure sustainable and resilient food production systems, but there are no clear patterns on how landscape complexity (defined as proportion of natural or seminatural habitat in a focal landscape) and biodiversity affects them. Insect pests of crops cause billions of dollars of losses each year. While insecticides are effective in the short term, they are costly and negatively affect non-target species, ultimately disrupting ecosystems and reducing sustainability. Using existing natural enemies (predators and parasitoids) to provide pest control services is cost-free and can improve sustainability, but many of the underlying mechanisms by which natural enemies control pests remain poorly understood. The long-term goal of my research program is to understand interactions among plants, herbivore pests and natural enemies in agricultural landscapes, with the aim to enhance arthropod-mediated ecosystem services. Landscape complexity decreases with increased agricultural intensification, reducing natural enemy populations, but recent work found inconsistent patterns between landscape complexity and pest control, highlighting the need for a mechanistic understanding of BEF relationships at the landscape scale. Shifting the focus from taxonomic diversity to the diversity of functional traits (body size, feeding specialization, activity period, etc.) has improved our understanding BEF relationships in plant and pollinator communities, but has seldom been investigated for natural enemy communities. Over the next five years, I will train 14 students while we investigate the effects of landscape complexity on the functional diversity of natural enemies and pests in agroecosystems. We will examine how local filters (habitat identity and disturbance level) affect functional diversity by simultaneously sampling multiple habitats in focal landscapes. Using manipulative experiments, we will determine how the addition of flowering strips to field borders affects natural enemy functional diversity and pest control in crops, and how this is moderated by landscape complexity. Finally, using molecular gut content analyses, we will examine the association between levels of pest control and natural enemy functional diversity. This research will aid in determining what amount and arrangement of suitable natural enemy habitat is ideal to support functional natural enemy communities and maximize pest control in agricultural landscapes.

生物多样性与生态系统功能（BEF）之间的关系是我们理解群落生态学的核心。虫害控制等生态系统服务（即有益于人类的生态系统功能）对于确保可持续和有复原力的粮食生产系统至关重要，但在景观复杂性（定义为重点景观中自然或非自然生境的比例）和生物多样性如何影响它们方面，没有明确的模式。农作物的虫害每年造成数十亿美元的损失。虽然杀虫剂在短期内是有效的，但它们成本高昂，对非目标物种产生负面影响，最终破坏生态系统，降低可持续性。利用现有的天敌（捕食者和拟寄生物）提供虫害控制服务是免费的，可以提高可持续性，但天敌控制虫害的许多基本机制仍然知之甚少。 我的研究项目的长期目标是了解农业景观中植物，植食性害虫和天敌之间的相互作用，旨在提高节肢动物介导的生态系统服务。景观复杂性随着农业集约化程度的提高而降低，减少了天敌种群，但最近的工作发现景观复杂性和害虫控制之间的模式不一致，突出了在景观尺度上对BEF关系的机械理解的必要性。将重点从分类多样性转移到功能性状的多样性（体型、食性、活动期等）提高了我们对植物和传粉者群落中BEF关系的理解，但很少对天敌群落进行研究。在接下来的五年里，我将培训14名学生，同时我们调查景观复杂性对农业生态系统中天敌和害虫功能多样性的影响。我们将研究当地的过滤器（栖息地的身份和干扰水平）如何影响功能多样性，同时采样多个栖息地的焦点景观。使用操纵实验，我们将确定如何增加开花带的字段边界影响天敌功能多样性和作物害虫防治，以及这是如何缓和景观复杂性。最后，利用分子肠道内容物分析，我们将研究害虫控制水平和天敌功能多样性之间的关联。这项研究将有助于确定合适的天敌栖息地的数量和安排是理想的，以支持功能性天敌群落，并最大限度地控制农业景观中的害虫。