Forums | HES 健康与环境科学

11 March 2024, 10:49 AM

Speaker: Yu Zeng (online)

Date: 2024-03-14

Time: 13:00-13:30 

Room: ES354

Online link:

https://meeting.tencent.com/dm/v169BGHYrPM6

Meeting ID: 668-4466-7997

Title: Urbanization and community structure: the impact of habitat transformation on competition and predation in passerine assemblages

Abstract:

Ecology seeks to explain how and why species coexist, and how community assembly determines ecosystem functioning. Urbanization provides a great opportunity to answer these questions because, across transformation gradients, specialists are substituted by generalists resulting in increased functional and phylogenetic similarity. According to the niche theory, coexistence is favoured by niche partitioning, so that increasing similarity would enhance competition, yet mediated by habitat productivity. However, it is unclear how these bottom-to-top processes (the relationships among productivity, niche structure and competition) interact to shape top to bottom processes (predation rates). Theoretically, increasing competition and decreasing productivity would enhance predation pressure from predators to prey, which would be reinforced by low prey selectivity of generalist species. As a result, it would be expected that predation pressure would be higher in transformed habitats. Interestingly, there are studies showing that predation rate could be higher or lower across transformation gradients. A key component of this issue is the diverse methodologies employed to study this process, which might result in biases and may make difficult reaching solid conclusions.