Overcoming establishment thresholds for peat mosses in human-made bog pools

Area of Science:

• Ecology
• Restoration Ecology
• Environmental Science

Background:

• Peatlands globally impacted by drainage and extraction, affecting ecosystem services.
• Rewetting drained bogs can create deep lakes, hindering peat moss revegetation due to abiotic factors.
• Floating peat mats and open bog lakes may represent alternative stable states.

Purpose of the Study:

• To theoretically explore if floating peat mats and open bog lakes are alternative stable states.
• To experimentally test for stable states and state shifts using floating structures in human-made bog lakes.
• To assess the role of water depth and substrate addition in peat moss restoration.

Main Methods:

• Developed a simple model to analyze alternative stable states.
• Conducted field experiments using biodegradable floating structures mimicking buoyant peat.
• Transplanted Sphagnum cuspidatum and S. palustre with and without organic substrate.

Main Results:

• Model and experiment confirmed open water and floating peat mats as alternative stable states.
• Floating structures facilitated pioneer Sphagnum cuspidatum and vascular plant growth.
• Water depth below 0.29m limited natural peat moss recovery; organic substrate enhanced vascular plants.

Conclusions:

• Open water and floating peat mats are distinct stable states in human-made bog lakes.
• Floating structures can induce a state shift towards peat-forming vegetation.
• Successful restoration requires considering water depth thresholds and appropriate species selection, not necessarily donor peat.