Facilitative plant interactions and climate simultaneously drive alpine plant diversity

Area of Science:

• Ecology
• Biodiversity Science
• Climate Change Research

Background:

• Species interactions are key drivers of local biodiversity.
• The influence of biotic interactions on larger scales is often underestimated compared to climate.
• Quantitative comparisons of biotic interactions versus other drivers at large scales are scarce.

Purpose of the Study:

• To assess the relative importance of biotic interactions and climate in determining plant diversity across alpine ecosystems globally.
• To investigate the role of nurse-plant cushion species in maintaining plant diversity.
• To integrate climate and species interaction effects for predicting future biodiversity changes.

Main Methods:

• Utilized a global dataset from 78 diverse sites across five continents.
• Analyzed the correlation between climate variables (especially water balance) and plant species richness.
• Quantified the contribution of nurse-plant cushion species to plant diversity.

Main Results:

• Climate variables related to water balance showed the strongest global correlation with plant species richness.
• Nurse-plant cushion species had a substantial, though lesser, effect on diversity compared to climate.
• Cushion species significantly enhanced species richness in areas with naturally low diversity.

Conclusions:

• Both climate and biotic interactions are critical for plant diversity at larger scales.
• Nurse species act as a 'safety net,' sustaining biodiversity under challenging climatic conditions.
• Integrating climate and species interactions is essential for accurate biodiversity change predictions.