Roles of bats in top-down forces across elevations, strata, and latitudes

Elise SIVAULT

Disertační práce

Diversity of bats along latitudinal, elevational and successional gradients and their trophic relationships with insect

Abstract:

In this thesis, I delve into the top-down regulation of arthropods and its indirect effects on herbivory, with a focus on the crucial role of bats as insect predators across different spatial scales. My primary objective was to enhance our understanding of bat ecology and their contribution to top-down control, comparing it to other predators across elevations of a tropical mountain. I found that only birds and bats have a significant impact on top-down control of herbivory across seasons and elevations. Additionally, this inquiry extended to evaluating the contributions of both birds and bats to top-down control in both the forest understory and the forest canopy of a temperate forest. I found that they both play a consistent role in preserving ecological balance across different layers of the forest. Finally, I explored this aspect in diverse temperate and tropical understory forests located at different latitudes. I found that birds and bats have consistent and comparable effects on arthropod densities across latitudes. However, I observed that top-down control of herbivory increased in forests rich in bat and bird species. Overall, this research underscores the critical importance of recognising bats as key predators influencing top-down forces within forest ecosystems. Furthermore, my findings highlight the complexity and interconnectivity of relationships across different trophic levels in undisturbed forests. This thesis paves the way for further research in other mountainous regions and diverse geographical areas.

Abstract:

In this thesis, I delve into the top-down regulation of arthropods and its indirect effects on herbivory, with a focus on the crucial role of bats as insect predators across different spatial scales. My primary objective was to enhance our understanding of bat ecology and their contribution to top-down control, comparing it to other predators across elevations of a tropical mountain. I found that only birds and bats have a significant impact on top-down control of herbivory across seasons and elevations. Additionally, this inquiry extended to evaluating the contributions of both birds and bats to top-down control in both the forest understory and the forest canopy of a temperate forest. I found that they both play a consistent role in preserving ecological balance across different layers of the forest. Finally, I explored this aspect in diverse temperate and tropical understory forests located at different latitudes. I found that birds and bats have consistent and comparable effects on arthropod densities across latitudes. However, I observed that top-down control of herbivory increased in forests rich in bat and bird species. Overall, this research underscores the critical importance of recognising bats as key predators influencing top-down forces within forest ecosystems. Furthermore, my findings highlight the complexity and interconnectivity of relationships across different trophic levels in undisturbed forests. This thesis paves the way for further research in other mountainous regions and diverse geographical areas.

Keywords

top-down control, species richness, trophic cascades, chiroptera, elevation, latitude, herbivory, arthropods

Jazyk práce: angličtina

Datum vytvoření / odevzdání či podání práce: 15. 3. 2024

Obhajoba závěrečné práce

• Vedoucí: Mgr. Kateřina Sam, Ph.D.

JIHOČESKÁ UNIVERZITA V ČESKÝCH BUDĚJOVICÍCH

Přírodovědecká fakulta

Doktorský studijní program / obor:
Zoology / Zoology