Wood density predicts plant damage and vegetative recovery rates caused by cyclone disturbance in tropical rainforest tree species of North Queensland, Australia

Abstract

The ability to withstand disturbance (resistance) and the ability to recover biomass following disturbance (resilience) were investigated in Australian wet tropical rainforest tree species. These two attributes are expected to be negatively correlated, because investment of biomass in structural support (conferring resistance) results in trees exhibiting high wood densities and slow growth rates, and vice versa.We examined species' responses to disturbance caused by a severe tropical cyclone to test this hypothesized trade-off. We assessed cyclone damage in six species in three Mabi rainforest fragments on the Atherton Tablelands. Species differed in the proportion of individuals within four damage categories (minor damage, severe branch damage, snapped, uprooted). Resistance was positively related to wood density.We found a positive correlation between the proportion of trees experiencing minor damage only and wood density, supporting the hypothesized association between resistance and mechanical strength. Among the subset of trees in which stems snapped, rates of resprouting differed between species and were highest in low wood density species and lowest in species with highest wood density. Resilience, characterized as the ability to recover biomass following disturbance and estimated as growth rate standardized for stem diameter at breast height (g day -1 · mm -1 ), was negatively related to wood density. Thus, species with low wood densities were more likely to suffer stem and branch damage owing to cyclonic winds, but also demonstrated highest resprouting and fastest responses in terms of redeveloping biomass in the 8 months following disturbance. This suggests that a species' position along the resistance-resilience spectrum can be predicted by mean wood density, which may allow managers to predict species' responses to future cyclones. Our findings also provide mechanistic evidence for the 'direct regeneration' model of post-cyclone succession, where response is characterized by resprouting and species composition is unchanged.

Evaluating the vegetation destruction and recovery of Wenchuan earthquake using MODIS data

“…For example, anomalously warming decreases net ecosystem carbon dioxide exchange (NEE) by inducing drought that suppressed NPP in the extreme year and by stimulating heterotrophic respiration of soil biota in the subsequent year (Arnone et al 2008;Phillips et al 2009). Cyclone may cause uprooted, snapped, severe branch damage and minor damage which affect the structure and function of forest ecosystem, and species differed in the proportion of individuals within various damage extents (Chambers et al 2007; Curran et al, 2008;Turton 2008). Compared with other disturbances events, earthquake has different mechanism to affect trees.…”

Comparison of Wood Density and Water Content Between Dry Evergreen and Dry Deciduous Forest Trees in Central Cambodia

“…For example, trees with low wood density exhibit a faster growth rate compared with trees of high wood density, whereas trees with high wood density usually have a high survival rate due to their stronger resistance to physical stress, pathogens, and pest attacks (Curran et al 2008, King et al 2005, 2006, Kitajima 1994. Stem water storage is also related to wood density and may partially compensate for increases in drought stress in Central and South American dry tropical forest trees (Holbrook et al 1995, Meinzer et al 2004).…”

Impacts of wind disturbance on fragmented tropical forests: A review and synthesis

“…Resprouting is the most common mechanism in tropical forests, followed by sapling regeneration (Walker 1991;Bellingham et al 1994;Zimmerman et al 1994;Burslem et al 2000). These mechanisms favour species with strong resprouting capacity and high growth rates, traits that are often negatively correlated with wood density (Putz et al 1983;Curran et al 2008b).…”

“…In general, species best adapted to withstand storms fall into two categories: slow-growing, resistant species with high wood density and structural strength, or fast-growing, resilient species with low wood density and rapid recovery from defoliation and stem damage (Lawton 1984;Ostertag et al 2005;van Gelder et al 2006;Curran et al 2008b). These two life-history strategies are reflected in a range of plant functional traits (Table 1).…”