Climatic Seasonality in the Caatinga Ecosystem Shapes the Plant-herbivore Interactions Dynamic

Area of Science:

• Ecology
• Plant-Insect Interactions
• Tropical Biology

Background:

• Climatic seasonality is a major driver of ecological processes in tropical ecosystems.
• Understanding plant defense mechanisms and their influence on herbivore communities is crucial for ecosystem dynamics.

Purpose of the Study:

• To investigate the effects of climatic seasonality on the plant defense mechanisms of *Ipomoea carnea* subs. *fistulosa*.
• To assess how these plant responses influence the richness and abundance of different herbivore guilds.

Main Methods:

• Conducted 12-month herbivore collections and monitored plant phenology and herbivory on 30 marked plants.
• Analyzed herbivory index during dry and rainy seasons, alongside soil nutrient analysis.
• Categorized herbivores into orders and guilds to assess abundance and richness patterns.

Main Results:

• Plant phenology exhibited strong seasonality, with leaf/fruit emission in the dry season and bud/flower emission in the rainy season.
• Total herbivore abundance was higher in the dry season, while richness peaked in the rainy season.
• Specific herbivore guilds showed distinct seasonal patterns: leaf chewers-crushers dominated the dry season, while flower/bud chewers-crushers and suckers were more abundant in the rainy season.

Conclusions:

• Climatic seasonality strongly influences plant phenology, which in turn shapes herbivore abundance and richness patterns in Seasonally Dry Tropical Forests.
• Biotic factors like interspecific competition and resource availability interact with climatic factors to modulate these ecological relationships.