Plant Litter Trait Variation Between Native and Invasive Species Across Steep Climate Gradients in the Hawaiian...

Area of Science:

• Ecology
• Island Biogeography
• Plant Trait Ecology

Background:

• Oceanic islands harbor high biodiversity threatened by invasive species.
• Invasive-native plant dynamics are often studied using live foliage traits, neglecting understudied litter traits.
• Island ecosystems face significant ecological disruption from invasive flora.

Purpose of the Study:

• To investigate native vs. invasive plant litter quality in Hawai'i's endemic flora.
• To synthesize litter trait data considering elevation and climate gradients.
• To understand the role of litter quality in invasive species expansion.

Main Methods:

• Conducted a systematic review of plant litter trait data from Hawai'i.
• Synthesized litter trait variability across elevation and climate gradients.
• Analyzed trait differences between native and invasive species, accounting for environmental factors.

Main Results:

• Litter quality varies extensively across Hawaiian Islands for both native and invasive species.
• Invasive plants generally have higher litter quality, but overlap with native species is considerable.
• Intraspecific variation in litter traits exceeds interspecific variation, emphasizing environmental heterogeneity.
• Climate influences litter quality differently for native and invasive species, causing strategy reversals.

Conclusions:

• Climate heterogeneity, rather than species origin, is the primary driver of plant litter trait variation.
• Environmental factors significantly shape plant litter traits and resource-use strategies on an archipelago scale.
• Litter quality sampling should be integrated into functional trait studies for a comprehensive understanding of invasive-native plant interactions.