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Pedro Rosero. Photo.

Pedro Rosero

Doctoral student

Pedro Rosero. Photo.

Conservation biological control in agricultural landscapes at the interface between ecology and evolution : The importance of land-use-mediated bottom-up ecological effects and eco-evolutionary dynamics

Author

  • Pedro Rosero

Summary, in English

Conservation biological control in agricultural landscapes aims to promote natural enemy populations to mitigate short and long-term pest damage on crops. However, natural enemy populations in agricultural landscapes typically rely on crop pests and non-pest prey populations resulting in complex trait- dependent ecological interactions. Such communities, of pests, non-pest prey, and natural enemies are affected by landscape heterogeneity depending on the dispersal capacity of the interacting organisms. For instance, changes in land use resulting in changes in the landscape-scale plant composition can result in bottom-up effects on herbivore communities and subsequently natural enemies affecting their ability to provide biological control. Such ecological time scale expectations do, however, not account for the possibility of adaptive niche shifts in both prey and natural enemies, making long-term predictions of biological control challenging. In this thesis, I acknowledge that natural enemies and their herbivore prey can adapt their niches in response to changes in land use. I analyse trait- and niche-based eco- evolutionary landscape models of land-use-mediated adaptive niche responses of interacting natural enemies and prey. I induce modifications in landscape heterogeneity through land-use change and (1) assess how biological control efficiency is affected for natural enemies with different dispersal capacities; (2) assess the effect of herbivore evolution on ecological interactions and, thus, biological control efficiency at ecological and eco-evolutionary timescales; (3) assess how herbivore and natural enemy co-evolution affects biological control; and (4) re-assess herbivore and natural enemy co-evolutionary effects on biological control in communities having different dispersal properties. I outline here the key findings of my thesis. (1) Variations in plant resource availability result in mismatches in functional traits between plants and herbivores, mismatches that lead to negative bottom-up effects on biological control. (2) Plant and herbivore trait mismatches also trigger herbivore evolution. Herbivore evolution in response to land-use change results in lowered herbivore efficiency on damaging the crop but at the cost of decreased biological control efficiency. (3) If natural enemies are allowed to co-evolve with herbivores, my results suggest that effects on biological control depend on which habitat is modified combined with which habitat the natural enemy is specialised towards. Whether evolution promotes or hinders biological control is thus highly dependent on the ecological characteristics (i.e. degree of specialization) of the natural enemy. (4) Furthermore, evolutionary effects on biological control are also highly dependent on organismal dispersal propensity. For example, only high-dispersing natural enemies can promote biological control regardless of specialisation whereas for low-dispersing ones biological control relies on their specialisation. These results highlight a novel evolutionary perspective on biological control and ultimately promote much-needed knowledge for long-term biological control sustainability in agricultural landscapes.

Department/s

  • Centre for Environmental and Climate Science (CEC)
  • BECC: Biodiversity and Ecosystem services in a Changing Climate
  • Biodiversity and Conservation Science

Publishing year

2024-05-10

Language

English

Document type

Dissertation

Publisher

MediaTryck Lund

Topic

  • Ecology
  • Environmental Sciences related to Agriculture and Land-use
  • Bioinformatics and Systems Biology
  • Evolutionary Biology

Keywords

  • Biological control
  • Eco-evolutionary dynamics
  • Landscape heterogeneity
  • Ecological modelling
  • Land-use change
  • Bottom-up effects

Status

Published

Research group

  • Biodiversity and Conservation Science

Supervisor

  • Henrik Smith
  • Mikael Pontarp

ISBN/ISSN/Other

  • ISBN: 978-91-8104-087-6
  • ISBN: 978-91-8104-088-3

Defence date

14 June 2024

Defence time

09:30

Defence place

Blå hallen, Ekologihuset

Opponent

  • Örjan Östman (Universitetslektor)