Abstract
Soils frequently experience environmental stresses that may have transient or persistent impact on important ecosystem
services, such as carbon (C) and nitrogen (N) cycling. Microbial communities underpin resistance (the ability to withstand a stress) and resilience (the ability to recover from a stress) of these functions. Whilst functional stability and resilience have been studied extensively, the link to genetic stability is missing.
In this study, the resistance and resilience of C mineralization, ammonia oxidation and denitrification, their associated gene
abundances (16S rRNA, bacterial amoA, nirK, nirS, nosZ-I and nosZ-II) and bacterial community structures (T-RFLP 16srRNA) were compared in two managed soils for 28 days after stressing
the soils with either a persistent (1 mg Cu soil g-1 34 ) or a transient (heat at 40 °C for 16 h) stress. The average resistance of C mineralization to Cu was 60%, which was significantly greater than the resistance of ammonia oxidation (25%) and denitrification (31%) to Cu. Similarly, the average resilience of C mineralization to Cu was 52%, which was significantly greater than the resilience of ammonia oxidation (12%) and denitrification (18%) to Cu. However, this pattern was not significant after heat stress, indicating the critical role of different stressors. Changes in total bacterial community structure rather than abundance of 16S rRNA reflected the responses of C mineralization to Cu and heat. Both Cu and heat
significantly decreased functional gene abundance (amoA, nirK, nirS, nosZ-I and nosZ-II), however, significant recovery of
denitrifying gene abundance was observed after 28 days following heat. There was lack of constant relationships between functional and genetic stability, highlighting that soil physiochemical properties, the nature of the stressor, and
microbial life history traits combine to confer functional resistance and resilience. Genetic responses on their own are therefore inadequate in predicating changes to soil functions following stresses.
services, such as carbon (C) and nitrogen (N) cycling. Microbial communities underpin resistance (the ability to withstand a stress) and resilience (the ability to recover from a stress) of these functions. Whilst functional stability and resilience have been studied extensively, the link to genetic stability is missing.
In this study, the resistance and resilience of C mineralization, ammonia oxidation and denitrification, their associated gene
abundances (16S rRNA, bacterial amoA, nirK, nirS, nosZ-I and nosZ-II) and bacterial community structures (T-RFLP 16srRNA) were compared in two managed soils for 28 days after stressing
the soils with either a persistent (1 mg Cu soil g-1 34 ) or a transient (heat at 40 °C for 16 h) stress. The average resistance of C mineralization to Cu was 60%, which was significantly greater than the resistance of ammonia oxidation (25%) and denitrification (31%) to Cu. Similarly, the average resilience of C mineralization to Cu was 52%, which was significantly greater than the resilience of ammonia oxidation (12%) and denitrification (18%) to Cu. However, this pattern was not significant after heat stress, indicating the critical role of different stressors. Changes in total bacterial community structure rather than abundance of 16S rRNA reflected the responses of C mineralization to Cu and heat. Both Cu and heat
significantly decreased functional gene abundance (amoA, nirK, nirS, nosZ-I and nosZ-II), however, significant recovery of
denitrifying gene abundance was observed after 28 days following heat. There was lack of constant relationships between functional and genetic stability, highlighting that soil physiochemical properties, the nature of the stressor, and
microbial life history traits combine to confer functional resistance and resilience. Genetic responses on their own are therefore inadequate in predicating changes to soil functions following stresses.
| Original language | English |
|---|---|
| Article number | 103308 |
| Number of pages | 10 |
| Journal | European Journal of Soil Biology |
| Volume | 104 |
| Early online date | 10 Mar 2021 |
| DOIs | |
| Publication status | Published - May 2021 |
Bibliographical note
AcknowledgementsWe acknowledge support from the Rural & Environment Science & Analytical Services Division of the Scottish Government and the International Studentship programme of SRUC. We thank the help from John Parker and Annette Raffan in setting up these experiments.
Keywords
- microbial community
- mineralization
- denitrification
- ammonia oxidation
- stresses
- sustainability