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。害虫防治等生态系统服务（即有利于人类的生态系统功能）对于确保可持续和有抵御力的粮食生产系统至关重要，但关于景观复杂性（定义为焦点景观中自然或半自然栖息地的比例）和生物多样性如何影响它们，目前尚无明确的模式。农作物的害虫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，但它们是昂贵的，并对非目标物种产生负面影响，最终破坏生态系统并降低可持续性。利用现有的天敌（捕食者和寄生虫）提供虫害防治服务是免费的，可以提高可持续性，但对天敌控制害虫的许多潜在机制仍然知之甚少。我研究项目的长期目标是了解农业景观中植物、草食害虫和天敌之间的相互作用，以增强节肢动物介导的生态系统服务。随着农业集约化程度的提高，景观复杂性降低，天敌数量减少，但最近的工作发现景观复杂性与害虫控制之间的模式不一致，强调需要在景观尺度上对BEF关系进行机制理解。将焦点从分类多样性转移到功能性状（体型、摄食专一性、活动期等）的多样性，提高了我们对植物和传粉昆虫群落间BEF关系的认识，但很少对天敌群落的BEF关系进行研究。在接下来的五年里，我将培训14名学生，同时我们将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。我们将通过同时采样焦点景观中的多个栖息地来研究局部过滤器（栖息地身份和干扰水平）如何影响功能多样性。通过操作实验，我们将确定在田间边界增加开花带如何影响农作物的天敌功能多样性和害虫控制，以及景观复杂性如何调节这种影响。最后，利用分子肠道含量分析，我们将研究害虫控制水平与天敌功能多样性之间的关系。该研究将有助于确定适宜的天敌生境的数量和安排，以支持功能性天敌群落和最大限度地控制农业景观中的害虫。