Thresholds of biodiversity and ecosystem function in a forest ecosystem undergoing dieback

Area of Science:

• Ecology
• Environmental Science
• Forest Science

Background:

• Ecological thresholds signify critical points of abrupt change in ecosystems.
• Empirical research on thresholds in temperate terrestrial ecosystems remains limited.
• Forest dieback is a growing global concern due to climate change.

Purpose of the Study:

• To empirically test for ecological thresholds in temperate terrestrial ecosystems.
• To investigate responses of biodiversity, ecosystem function, and condition metrics to forest dieback.
• To understand the implications of threshold responses in a changing climate.

Main Methods:

• Assessed a gradient of forest dieback using basal area of living trees.
• Utilized 12 replicate study areas in a temperate forest ecosystem.
• Measured biodiversity (fungi, lichen, flora), ecosystem function (soil respiration), and condition (sward height, seedling abundance).

Main Results:

• Evidence of thresholds in ectomycorrhizal fungi, epiphytic lichen, and ground flora species richness.
• Observed thresholds in ecological condition metrics like sward height and palatable seedling abundance.
• Identified a threshold in ecosystem function, specifically soil respiration rate.

Conclusions:

• Temperate forest ecosystems exhibit ecological thresholds in response to forest dieback.
• Thresholds impact biodiversity, ecological condition, and ecosystem function.
• Increasing forest dieback suggests a rise in widespread threshold responses globally.