Comparison of Structural Characteristics among Different Types of Limestone Forests in Cat Ba Biosphere Reserve, Vietnam

Abstract

Vietnams forests have long been known for their rich and diverse fauna and flora. However, the country has experienced significant deforestation and forest degradation due to human activities in the past decades. In response, various scientific works as well as technical solutions have been developed to reverse this trend. This study was conducted to assess the ecological characteristics of limestone forests with different management practices (no logging, post-selective logging, and post-clear-cut forests) and mixed plantations for the restoration and sustainable management of degraded natural limestone forests in the Cat Ba Biosphere Reserve, Vietnam. Structural characteristics of overstory as well as understory were investigated and then evaluated. The results showed that post-selective logging and post-clear-cut forests had much less number of tree species than no-logging forests. Several poor forest stands showed that the natural restoration of degraded limestone forests to the level of unimpacted primeval state could be very slow, or nearly impossible. Mixed plantations showed better signs of reasonable growth, the presence of various valuable species as well as higher biodiversity index than the naturally regenerated post-logged forests, and were nearly comparable to the no logged forest. Some limitation still existed in enrichment planting, such as high planting density and lower soil fertility than no-logged forests. These findings implied that further silvicultural and ecological techniques should be developed to improve the existing models as well as to be the basis for future measures in similar sites.