Red-listed tree species abundance in montane forest areas with differing levels of statutory protection in north-western Vietnam

Abstract

Statutes, regulations, and forest restoration represent measures aimed at promoting the conservation of threatened species. We analyzed the abundance of red-listed tree species within three conservation zones with differing levels of protection in the Ta Xua Nature Reserve in north-western Vietnam, a rarely studied region within a biodiversity hotspot. The study area included: (1) the undisturbed core zone; (2) the low intensity traditional forest use buffer zone; and (3) the forest restoration zone. Red-listed tree species richness (IUCN and Vietnamese Red Lists combined) amounted to 16 in the core zone, 10 in the buffer zone, and five in the restoration zone; a similar declining trend was found for all tree species at 193, 173 and 135 for each respective zone. Differences between zones were even more pronounced when species richness was predicted using the Chao2 estimator. Most red-listed species, such as Fujian Cypress (Fokienia hodginsii), reached their highest densities in the core zone, but one species (Quercus platycalyx) was quite abundant in the restoration zone. For some red-listed tree species, canonical correspondence analysis suggested relationships among the presence of footpaths, canopy closure and basal area, suggesting reduced abundance caused by human activities. Our data indicate that conservation effectiveness is related to the level of statutory protection afforded to a particular area, with full protection ensuring more robust conservation outcomes.