Competition-colonization trade-offs and disturbance effects at multiple scales

Area of Science:

• Ecology
• Community Ecology
• Biodiversity Research

Background:

• The competition-colonization trade-off is a key mechanism explaining species coexistence and diversity in nonequilibrium systems.
• The intermediate disturbance hypothesis (IDH) suggests maximal diversity at intermediate disturbance frequencies, but empirical support is limited.
• This trade-off is also a significant factor in explaining species coexistence at larger spatial scales.

Purpose of the Study:

• To investigate how the distribution of species traits along the competition-colonization trade-off influences the relationship between disturbance and diversity.
• To determine if this relationship differs at local versus larger spatial scales.

Main Methods:

• Utilized a microbial experimental system to study the diversity-disturbance relationship.
• Manipulated disturbance frequencies and observed effects on species diversity.
• Analyzed the distribution of species traits, specifically their position along the competition-colonization trade-off.

Main Results:

• When species traits were skewed towards late-successional habits, local species diversity declined as disturbance increased.
• Despite this trait skew, species diversity at spatial scales larger than the individual patch remained largely insensitive to the trait distribution.
• Intermediate disturbance frequencies maximized diversity within the patch successional stage, benefiting the most species at larger scales.

Conclusions:

• The impact of the competition-colonization trade-off on diversity is scale-dependent.
• Local diversity patterns are sensitive to trait distribution, particularly under high disturbance.
• Larger-scale diversity is more robust to trait distribution, with intermediate disturbance promoting coexistence.