Drought negatively affects communities on a foundation tree: growth rings predict diversity

Area of Science:

• Ecology
• Climate Change Biology
• Arthropod Ecology

Background:

• Understanding ecosystem responses to climate change is crucial for biodiversity conservation.
• The plant vigor and stress hypotheses offer frameworks for predicting arthropod responses to environmental stress.
• These hypotheses are seldom tested at the community level, especially following extreme climatic events.

Purpose of the Study:

• To investigate how arthropod communities on pinyon pine (Pinus edulis) are affected by drought-induced tree stress.
• To test the plant vigor and stress hypotheses at the community level.
• To identify patterns of arthropod community alteration in response to climate change impacts.

Main Methods:

• Comparison of arthropod communities on pinyon pine trees exhibiting a gradient of drought stress.
• Assessment of tree physical traits related to stress, including growth rate, branch dieback, and needle retention.
• Analysis of arthropod species richness, abundance, and community structure in relation to tree stress levels.

Main Results:

• Increasing tree stress led to an eight to tenfold decline in arthropod species richness and abundance.
• Arthropod communities on trees with similar stress levels were more alike.
• Tree radial growth during drought positively correlated with arthropod richness and abundance, suggesting tree ring analysis as a potential predictor of arthropod diversity.
• Both foliage quantity and quality influenced arthropod community structure.

Conclusions:

• Extreme drought significantly alters arthropod community composition and reduces multi-trophic diversity.
• Foundation tree species health is a key factor influencing associated arthropod communities.
• Findings suggest potential cascading effects on other taxa within the ecosystem due to climate change-induced stress on dominant plant species.