Emission variations of GLVs from woody plants upon mechanical damage reflect trait-mediated physio-ecological...

Mechanical damage markedly modifies the emission patterns of green leaf volatiles (GLVs), which serve as key signaling compounds in plant defense, yet interspecific variations across diverse tree species and their linkage to ecological adaptation remain poorly characterized. This study systematically analyzed GLVs (aldehydes, alcohols, esters) in 45 tree species (19 deciduous, 26 evergreen) under both intact and mechanically wounding conditions, integrating leaf functional traits and ecological strategy types. Intact leaves emitted low levels of GLVs, primarily esters. Wounding increased total emissions 5- to 200-fold, with alcohols and aldehydes rising most sharply; over 80% of post-wounding compounds were newly induced. Deciduous species exhibited significantly higher GLVs emissions and wound responsiveness than evergreens. Green leaf volatiles emissions correlated closely with leaf dry mass per area (negative) and leaf water content (leaf water content, positive), and differed among ecological strategy types. Wounding enhanced synergies between GLVs, monoterpenes and aromatic compounds within the biogenic volatile organic compound blend, forming an integrated defense network whose structure depended on life form. Green leaf volatile emission patterns also aligned with species' dominant volatile metabolism: isoprene-emitting deciduous trees showed intense aldehyde bursts, whereas monoterpene-emitting evergreens maintained stronger ester monoterpene coupling. Our findings demonstrate that mechanical injury reprograms GLV emissions in a trait- and strategy-dependent manner, reflecting evolutionary trade-offs between growth and defense. This study provides a trait-based physio-ecological framework that links leaf economics, volatile metabolism and network-level coordination, offering a mechanistic basis for selecting stress-resilient trees and refining forest emission models under environmental disturbance.