Tadpole aggregations create biogeochemical hotspots in wetland ecosystems

Area of Science:

• Ecology
• Biogeochemistry
• Environmental Science

Background:

• Animal waste is a known driver of nutrient cycling and ecosystem productivity.
• The specific biogeochemical impacts of animal excretion in wetland ecosystems remain understudied.
• Wood frogs (Lithobates sylvaticus) form aggregations in geographically isolated wetlands.

Purpose of the Study:

• To investigate the effects of wood frog tadpole aggregations on nutrient cycling, microbial metabolism, and carbon cycling in wetlands.
• To understand how tadpole development and excretion influence wetland biogeochemistry.
• To assess the functional role of tadpole aggregations in wetland ecosystem processes.

Main Methods:

• Paired mesocosm and field studies were conducted.
• Measurements included tadpole excretion rates, microbial extracellular enzyme activities, and litter degradation.
• Ambient nutrient concentrations were compared between wetlands with and without tadpole aggregations.

Main Results:

• Tadpole development showed a strong relationship with nutrient excretion, indicating ontological shifts impact nutrient cycling.
• Tadpole excretion, combined with hydrologic conditions, increased ambient nitrogen and phosphorus concentrations significantly.
• Microbes reduced nitrogen-acquisition enzyme production in response to tadpole-derived nitrogen.
• Tadpole presence enhanced litter breakdown by 7% in mesocosms and 12% in field studies.

Conclusions:

• Tadpole aggregations play a significant functional and biogeochemical role in wetland habitats.
• Tadpole excretion influences nutrient availability, microbial metabolism, and carbon cycling.
• These findings have implications for wetland ecosystem processes, biodiversity conservation, and management strategies.