Damage by typhoon Hato compared among three different plant communities in Macau, China

Abstract

Tropical cyclones are among the major climatic disasters threatening human survival and development. They are also responsible in part for forest taxonomic composition and dynamics and may lead to catastrophic succession between ecosystems. In this study, we aimed to investigate the extensiveness and severity of the effect caused by Typhoon Hato among the three primary plant communities in Macau, China, including Guia Hill, Taipa Grande, and Ka Ho. The plants' damage was classified into seven categories, ranging from Degree 6, which represents the most severe damage, to Degree 0, which represents almost no damage. The impact of Typhoon Hato was evaluated at different levels, including sample plots, species, DBH, and community structure. Our results show that the sub-climax community of Guia Hill was most disturbed, with the highest damage index (DI) of 55.28%. Similarly, the Ka Ho shoreline shrub community was also considerably influenced, with a DI of 48.14%. By contrast, the managed secondary forest around Taipa Grande was the least affected, with a DI of 32.66%. Additionally, from the tree layer perspective, the tall trees at Guia Hill canopy layer were directly affected by wind, while the dense understory layer suffered from severe secondary damage due to the fallen trees and branches. For Taipa Grande, the dominant species in the canopy layer were shorter and had less direct damage; the secondary damage was also small as a consequence. Ka Ho had more dwarfed and multibranched species surviving from the sea breeze since Ka Ho was close to the sea. The dense plant structure in Ka Ho protected plants from being easily broken by typhoons, but some twigs and leaves were lost. Some less damaged local species and easily recovered species found in this study could inform the selection of wind-resistant species for the typhoon-affected communities.

Keywords: community structure; diameter at breast height; succession; tree layers; tropical cyclone; wind damage.