Stochastic colonization, transient and boom-bust dynamics shape invasions by native taxa

Area of Science:

• Ecology
• Population Dynamics
• Conservation Biology

Background:

• Boom-bust dynamics (BBD) describe population explosions followed by crashes, often studied in invasive species.
• Understanding BBD is crucial for invasion ecology and management, but data scarcity limits knowledge, especially for native species in restored habitats.
• Restored ecosystems provide a unique setting to study BBD without confounding factors from non-native species.

Purpose of the Study:

• To investigate the occurrence and drivers of BBD in native waterbird communities recolonizing restored wetlands.
• To determine the long-term persistence of colonizing species and assess the prevalence of transient dynamics.

Main Methods:

• Analyzed BBD in 47 breeding waterbird species across 53 wetland patches from 1984 to 2023.
• Studied populations in restored habitats where ecological processes, not non-native traits, drove recolonization.
• Examined the influence of patch features, hydrology, and species traits (generalist vs. rare) on BBD patterns.

Main Results:

• BBD was observed in over 75% of waterbird species and the community, exhibiting single and recurring patterns.
• Stochastic hydrology and generalist species were key factors associated with BBD.
• Only ~20% of colonizations led to long-term persistence; most resulted in local extinctions, indicating widespread failed attempts.

Conclusions:

• BBD is prevalent in native species recolonizing restored habitats, driven by intrinsic ecological processes.
• The study challenges the notion that BBD are exclusive to invasive species, suggesting broader applicability.
• Failed colonization attempts are common, necessitating a re-evaluation of population dynamics in ecological restoration and invasion contexts.