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）之间的关系对于我们对社区生态的理解至关重要。生态系统服务（即受益于人类的生态系统功能）等生态系统服务对于确保可持续和弹性的粮食生产系统至关重要，但是尚无关于景观复杂性（定义为焦点景观中自然或半自然栖息地的比例）的明确模式，并且生物多样性影响它们。农作物的害虫每年造成数十亿美元的损失。尽管杀虫剂在短期内有效，但它们既昂贵又负面影响非目标物种，最终破坏了生态系统并降低了可持续性。使用现有的天然敌人（捕食者和寄生虫）提供有害生物控制服务是免费的，可以提高可持续性，但是自然敌人控制害虫的许多基本机制仍然知之甚少。 我的研究计划的长期目标是了解农业景观中植物，草食动物害虫和自然敌人之间的相互作用，以增强节肢动物介导的生态系统服务。景观复杂性随着农业强化的增加而降低，减少了自然敌人的种群，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，强调了在景观规模上对BEF关系的机械理解的需求。将重点从分类学多样性转移到功能性状的多样性（体型，喂养专业化，活动期等）已改善了我们在植物和传粉媒介社区中的BEF关系，但很少对自然敌人社区进行调查。在接下来的五年中，我将培训14名学生，同时我们研究景观复杂性对农业生态系统中天然敌人和害虫功能多样性的影响。我们将研究局部过滤器（栖息地身份和干扰水平）如何通过同时在局灶性景观中采样多个栖息地来影响功能多样性。使用操纵实验，我们将确定在野外边界中增加开花条如何影响农作物中的天然敌人功能多样性和害虫控制，以及如何通过景观复杂性来调节这种情况。最后，使用分子肠道含量分析，我们将研究害虫控制水平与天然敌人功能多样性之间的关联。这项研究将有助于确定合适的天然敌人栖息地的数量和布置是支持功能性天然敌人社区并最大程度地控制农业景观中的害虫。