Nutrient currencies and P resorption greatly amplify the perceived costs of reproductive allocation in perennial heath shrubs

Wenk, E.; Falster, D. S.; Wright, I. J.; Westoby, M.

doi:10.64898/2026.06.10.731282

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bioRxiv · 10.64898/2026.06.10.731282

Nutrient currencies and P resorption greatly amplify the perceived costs of reproductive allocation in perennial heath shrubs

Wenk, E.·Falster, D. S.·Wright, I. J.·Westoby, M.

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Abstract

SummaryO_LIIn woody perennials, reproductive allocation considered as a fraction of NPP (RA) has been rarely quantified, especially tracked across plant lifetimes, measured in biologically meaningful currencies, and separated from standing biomass. C_LIO_LIWe addressed this gap by measuring dry mass, nitrogen, and phosphorus for every aboveground tissue type for 14 iteroparous perennial shrubs tracked across their full lifetimes, calculating RA using four accounting schemes and three currencies. C_LIO_LIRA was substantially higher by mid-life than typical estimates from ecosystem-scale studies. Distinguishing standing biomass from yearly production further revised RA upwards. Using a nutrient currency (especially P) increased the perceived costs of reproduction. Propagules were highly nutrient-enriched and reproductive accessory costs consumed more nutrients than did the propagules themselves. Considering N and P resorption from senescing leaves and wood shrank the effective vegetative nutrient budget, further concentrating net annual nutrient demand in reproductive tissues. C_LIO_LIOur results highlight high investment in RA for woody perennials, especially using nutrient currencies. Broadly similar allocation patterns were observed across species with different functional traits and lifespans, suggesting generality that may apply across biomes. Widespread underestimation of RA in forest growth models likely overestimates the proportion of NPP available for vegetative growth, leading to substantial errors in predictions. C_LI

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Wenk, E., Falster, D. S., Wright, I. J., Westoby, M.. 2026-06-12. Nutrient currencies and P resorption greatly amplify the perceived costs of reproductive allocation in perennial heath shrubs. https://doi.org/10.64898/2026.06.10.731282

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