Trophic structure modulates community rescue following acidification.

Area of Science:

• Ecology
• Environmental Science
• Community Ecology

Background:

• Community rescue is a phenomenon where ecosystems persist under lethal stress through the proliferation of rare resistant genotypes or species.
• Trophic structure, encompassing predator-prey relationships, significantly influences the dynamics of community rescue.
• The impact of environmental stress on different trophic levels can either facilitate or impede ecosystem recovery.

Purpose of the Study:

• To investigate how trophic interactions modulate community rescue under environmental stress.
• To determine the role of differential stress sensitivity across trophic levels in ecosystem resilience.
• To examine the effect of prior stress exposure on community recovery from acidification.

Main Methods:

• Utilized outdoor mesocosms to simulate a lake ecosystem with phytoplankton and zooplankton communities.
• Exposed the aquatic communities to controlled acidification stress.
• Manipulated prior stress exposure to assess its influence on rescue dynamics.

Main Results:

• Prior exposure to sublethal stress facilitated phytoplankton rescue from severe acidification.
• Community rescue was ultimately achieved even in previously less-stressed communities.
• The extinction of zooplankton predators, due to higher sensitivity to acidification, indirectly facilitated phytoplankton rescue.

Conclusions:

• Community rescue is significantly modulated by the differential impact of stress across trophic levels.
• Trophic structure can facilitate rescue when lower trophic levels are less affected by stress than their predators.
• The sensitivity of predators to environmental stress plays a critical role in the rescue of lower trophic levels.