Urbanization Pressures Alter Tree Rhizosphere Microbiomes
Abstract
Urban land development alters numerous environmental conditions including air temperature, rainfall quantity, and nutrient deposition in turn possibly effecting critical soil ecosystem services (e.g., carbon storage, soil water holding capacity). Urban soils experiencing increased inputs of heavy metals and nitrogen via atmospheric deposition and decreases in soil moisture via increased air temperatures could subsequently alter rhizosphere-microbiome (i.e., microbial communities associated with plant-roots) structure and activity. However, to our knowledge no study has assessed how urbanization pressures (i.e., temperature and pollutant deposition) influences the rhizosphere-microbiomes as well as soil carbon/nitrogen cycling in urban forests. Furthermore, structural differences between individual tree species is a potentially important mechanism facilitating the deposition of pollutants/nutrients to the soil, which is completely unknown. Addressing this fundamental gap in our understanding of urban soil processes, we used next generation high throughput sequencing to characterize bacterial members of the rhizosphere-microbiome of specific tree species (Fagus grandifolia vs Liriodendron tulipifera) across an urban-rural gradient. Sequence data was categorized against urbanization pressures assessed via environmental monitoring (i.e., soil moisture/temperature, relative humidity) in combination with soil chemistry observations (pH, organic matter, heavy metals and δ13C, δ15N). Our results suggest that bacterial rhizosphere-microbiomes are unique to individual tree species and differ significantly between urban vs rural forests. However, a lack of significant differences in soil chemistry measurements across our urban-rural gradient indicates soil chemistry is not a driving mechanism responsible for observed variation in the bacterial rhizosphere-microbiome. Urbanization pressures measured by environmental monitoring across the urban-rural gradient suggests soil moisture holding potential, soil temperature, air temperature, and relative humidity differences between urban and rural forests indicate that urban heat island effects potentially have a greater effect on the bacterial rhizosphere-microbiomes than changes in soil chemistry.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.B33O2896T
- Keywords:
-
- 0410 Biodiversity;
- BIOGEOSCIENCESDE: 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCESDE: 0465 Microbiology: ecology;
- physiology and genomics;
- BIOGEOSCIENCESDE: 0470 Nutrients and nutrient cycling;
- BIOGEOSCIENCES