Drought as a disturbance : Soil microbial resistance and resilience across environmental gradients
Winterfeldt, Sara LU
(2025)
- Abstract
- The ecosystem response to disturbances is a central topic in ecology, and there is growing awareness of the impacts of human-driven climate change on ecosystem stability to disturbances. Terrestrial ecosystems are increasingly exposed to more drought and rainfall events as climate change intensifies. In soils, bacteria and fungi play a key role in ecosystem functioning, yet their responses to drought disturbances are not fully understood. In this thesis, I investigated the drought stability of microbial growth and respiration, focusing on resistance (the ability to withstand drought) and resilience (the ability to recover after drought). I used different environmental gradients including geographical gradients and field manipulation... (More)
- The ecosystem response to disturbances is a central topic in ecology, and there is growing awareness of the impacts of human-driven climate change on ecosystem stability to disturbances. Terrestrial ecosystems are increasingly exposed to more drought and rainfall events as climate change intensifies. In soils, bacteria and fungi play a key role in ecosystem functioning, yet their responses to drought disturbances are not fully understood. In this thesis, I investigated the drought stability of microbial growth and respiration, focusing on resistance (the ability to withstand drought) and resilience (the ability to recover after drought). I used different environmental gradients including geographical gradients and field manipulation experiments to test how different factors including drought exposure history, soil properties, and plant diversity shape microbial responses to drought. I found that historical drought exposure increased bacterial drought resistance and resilience, suggesting that bacteria are more sensitive to drought in wetter climates, where drought is perceived as a more severe disturbance. Fungal growth was consistently both more resistant and resilient than bacterial growth. Interestingly, microbial carbon use efficiency (the partitioning between carbon used for growth and that released via respiration) after rewetting did not vary with climate. Other environmental factors also influenced microbial drought responses. Plant diversity had a positive effect on microbial resistance and resilience to drought. This might be due to increased access to plant-derived carbon at higher plant diversity, which could support microbial strategies to cope with drought. Surprisingly, other components of stability were unaffected by plant diversity. In contrast, lower soil pH reduced the resistance and resilience to drought, whereas soil texture, tillage, and increased temperature had negligible effects. Taken together, my findings show that climatic differences in drought exposure had a stronger effect than plant diversity in shaping microbial responses to drought. Identifying the environmental drivers of microbial growth and respiration stability improves our ability to predict microbial responses to future drought disturbances. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/7617c985-603c-484c-9110-dbac42c6249f
- author
- Winterfeldt, Sara
LU
- supervisor
-
- Johannes Rousk LU
- Lettice Hicks LU
- Albert Brangarí LU
- opponent
-
- Professor de Vries, Franciska, University of Amsterdam
- organization
- publishing date
- 2025
- type
- Thesis
- publication status
- published
- subject
- keywords
- climate change, drought, microbial ecology, microbial growth, respiration, rewetting
- pages
- 150 pages
- publisher
- Lund University
- defense location
- Blue hall, Ecology building, Lund
- defense date
- 2025-10-03 09:00:00
- ISBN
- 978-91-8104-594-9
- 978-91-8104-595-6
- project
- Soil microbial responses to drying and rewetting
- language
- English
- LU publication?
- yes
- id
- 7617c985-603c-484c-9110-dbac42c6249f
- date added to LUP
- 2025-09-08 10:47:14
- date last changed
- 2025-09-10 03:29:21
@phdthesis{7617c985-603c-484c-9110-dbac42c6249f,
abstract = {{The ecosystem response to disturbances is a central topic in ecology, and there is growing awareness of the impacts of human-driven climate change on ecosystem stability to disturbances. Terrestrial ecosystems are increasingly exposed to more drought and rainfall events as climate change intensifies. In soils, bacteria and fungi play a key role in ecosystem functioning, yet their responses to drought disturbances are not fully understood. In this thesis, I investigated the drought stability of microbial growth and respiration, focusing on resistance (the ability to withstand drought) and resilience (the ability to recover after drought). I used different environmental gradients including geographical gradients and field manipulation experiments to test how different factors including drought exposure history, soil properties, and plant diversity shape microbial responses to drought. I found that historical drought exposure increased bacterial drought resistance and resilience, suggesting that bacteria are more sensitive to drought in wetter climates, where drought is perceived as a more severe disturbance. Fungal growth was consistently both more resistant and resilient than bacterial growth. Interestingly, microbial carbon use efficiency (the partitioning between carbon used for growth and that released via respiration) after rewetting did not vary with climate. Other environmental factors also influenced microbial drought responses. Plant diversity had a positive effect on microbial resistance and resilience to drought. This might be due to increased access to plant-derived carbon at higher plant diversity, which could support microbial strategies to cope with drought. Surprisingly, other components of stability were unaffected by plant diversity. In contrast, lower soil pH reduced the resistance and resilience to drought, whereas soil texture, tillage, and increased temperature had negligible effects. Taken together, my findings show that climatic differences in drought exposure had a stronger effect than plant diversity in shaping microbial responses to drought. Identifying the environmental drivers of microbial growth and respiration stability improves our ability to predict microbial responses to future drought disturbances.}},
author = {{Winterfeldt, Sara}},
isbn = {{978-91-8104-594-9}},
keywords = {{climate change; drought; microbial ecology; microbial growth; respiration; rewetting}},
language = {{eng}},
publisher = {{Lund University}},
school = {{Lund University}},
title = {{Drought as a disturbance : Soil microbial resistance and resilience across environmental gradients}},
url = {{https://lup.lub.lu.se/search/files/227228357/Avhandling_Sara_Winterfeldt.pdf}},
year = {{2025}},
}