Competitors alter selection on alpine plants exposed to experimental climate change

Area of Science:

• Ecology
• Evolutionary Biology
• Plant Science

Background:

• Climate change is altering ecological conditions globally, necessitating an understanding of population adaptive potential.
• Previous research has primarily focused on direct climate impacts on selection, often overlooking the role of species interactions.
• Alpine ecosystems are particularly sensitive to climate warming, making them ideal for studying evolutionary responses.

Purpose of the Study:

• To investigate how climate warming and interspecific competition jointly influence phenotypic selection regimes in alpine plants.
• To quantify shifts in directional selection on plant morphology and phenology under different climate and competition scenarios.
• To determine whether competitive interactions mediate or impede evolutionary responses to climate change.

Main Methods:

• A transplant experiment was conducted along an elevation gradient to simulate warming conditions.
• Four alpine plant species were studied to assess phenotypic selection on key traits.
• Fitness components were measured in the presence and absence of competitors to evaluate interaction effects.

Main Results:

• Climate warming induced novel directional selection, significantly altering selection on specific leaf area and flowering time.
• Interspecific competition generally weakened or negated selection imposed by warming.
• Reduced fitness and fitness variation in the presence of competitors were associated with dampened selection.

Conclusions:

• While climate change can drive strong selection, competitive interactions can significantly limit the strength and direction of selection.
• Community context is crucial for predicting evolutionary trajectories of alpine plants under climate change.
• The interplay between climate warming and competition may hinder the adaptive capacity of alpine flora.