Abstract
Tropical cyclones dominate the disturbance regime experienced by forest
ecosystems in many parts of the world. Interactions between cyclone
disturbance regimes and nutrient availability strongly influence forest
ecosystem dynamics. However, uncertainty exists over the importance of
soil fertility properties (i.e., total soil phosphorus-P concentration)
in mediating forest resistance and recovery from cyclone disturbance. We
hypothesized that forests on soils with low total P (e.g., developed on
limited-P parent material) have a higher resistance to but a slower
recovery from cyclone disturbance than forests on high P soils. We
investigated cyclone impacts on litterfall, an essential conduit for
nutrient recycling in forest ecosystems. We compiled site-level forest
litterfall data from 53 studies and datasets associated with 15
naturally-occurring one simulated tropical cyclone in 23 sites within
five regions (Taiwan, Australia, Mexico, Hawaii, and the Caribbean)and
four cyclone basins. We calculated the effect sizes of cyclone
disturbance on the litterfall mass and nutrient (P and nitrogen-N)
concentrations and fluxes during the first (< five) years
post-disturbance across a total soil P gradient. We also assessed the
effect of 20 covariates on the degree of cyclone impact on litterfall.
Total litterfall mass flux increased by 4820%following cyclone
disturbance. Such an initial increase in litterfall mass reflects the
magnitude of cyclone-derived plant material input to the forest floor,
which was highest in the Caribbean and lowest in Taiwan. Among 20
covariates, soil P and region were the best predictors of cyclone
effects on total litterfall mass, explaining 80% of the variance. The
effect sizes increased linearly with soil P and region, from
significantly lower in Taiwan (low-P) to largest in the Caribbean
(high-P). Total litterfall P and N fluxes increased significantly
post-cyclone, whereas the increase in leaf P flux was twice as that in
Nflux. Results highlight the importance of understanding the
interactions between disturbance and nutrient gradients in forest
ecosystems to understand forest responses to altered cyclone regimes
expected under climate change.