Timing is everything: priority effects alter community invasibility after disturbance.

Area of Science:

• Ecology
• Community Ecology
• Invasion Biology

Background:

• Disturbances can increase ecosystem invasibility by freeing resources.
• However, established resident communities may monopolize resources, reducing subsequent colonization.
• Priority effects, where early species influence later ones, are key in press disturbances.

Purpose of the Study:

• To investigate how time since disturbance affects invasibility in tundra zooplankton communities.
• To determine the role of regional disperser arrival timing in relation to environmental change.

Main Methods:

• A fully factorial field mesocosm experiment was used.
• Tundra zooplankton communities were exposed to nutrient and salt additions (press disturbances).
• The arrival timing of regional dispersers was manipulated.

Main Results:

• Invasibility decreased as time since disturbance increased.
• Resident community abundance (nutrient treatments) and species richness (salt treatments) correlated with decreased invasibility.
• Priority effects were modified by the interplay of dispersal timing and environmental change.

Conclusions:

• Invasibility is time-dependent and influenced by resident community development.
• The timing of species dispersal relative to environmental change dictates the strength of priority effects.
• Understanding these dynamics is crucial for predicting community structure after press disturbances.