Invasive vegetation affects amphibian skin microbiota and body condition

Area of Science:

• Ecology
• Microbiology
• Conservation Biology

Background:

• Invasive plants, like Eucalyptus, significantly alter ecosystems globally.
• Eucalyptus leaf litter can change soil chemistry and harm soil-dwelling organisms.
• Amphibians are sensitive indicators of environmental change due to their skin's interaction with soil microbes.

Purpose of the Study:

• To investigate how Eucalyptus invasion affects soil and amphibian skin microbial communities.
• To compare the health and microbiome of the California slender salamander (Batrachoseps attenuatus) in Eucalyptus-dominated versus native Oak (Quercus agrifolia) forests.
• To assess the impact of vegetation type on amphibian body condition and pathogen presence.

Main Methods:

• Soil and Batrachoseps attenuatus skin microbial communities were sampled in Eucalyptus and Oak forests in the San Francisco Bay Area.
• Microbial diversity and composition were analyzed using sequencing.
• Salamander body condition and the prevalence of the pathogen Batrachochytrium dendrobatidis were assessed.

Main Results:

• Eucalyptus invasion showed minimal impact on soil microbial diversity but some effect on community structure.
• Batrachoseps attenuatus skin microbial diversity was higher in native Oak habitats.
• Salamanders in Oak habitats exhibited better body condition, and a specific bacterial group (Chlamydiaceae) was more abundant on salamanders in Eucalyptus habitats.

Conclusions:

• Eucalyptus invasion can negatively impact native amphibian health and skin microbiome diversity, even if soil microbial communities are less affected.
• The observed effects on body condition suggest cryptic negative impacts of invasive plants on wildlife.
• Further research is needed to understand the mechanisms driving these changes in native species' health and microbiomes following plant invasions.