In biodiversity conservation, e.g., bird conservation, it is a common sense that the primary forests are the crucial areas. However, due to the facts that most of the primary forests are restricted to ridges and are in decreasing in areas, whereas, quite large proportions mountainous regions are covered by human-modified forests, and species turnover changes rapidly along montane elevation gradients, it is important to recognize the roles the human-modified forests play in bird conservation.  

The help clear this issue, in a recent study conducted by the research team of Prof. Xiao-Jun Yang, Kunming Institute of Zoology (KIZ), Chinese Academy of Sciences (CAS), the bird diversity in four different habitats were evaluated, i.e., primary forests on ridges in the core area of the Ailaoshan National Nature Reserve, pine plantations growing Armand’s pine adjacent to ridges in the experimental zone of the Ailaoshan Reserve, secondary forests in the premontane part of the Konglonghe Municipal Nature Reserve, and mid-montane firewood forests not within a reserve.

Mountain systems are the hotspots of biodiversities. Ailao Mountain range, central of Yunnan Province, China, is part of the Indo-Burma biodiversity hotspot, including two critical areas for bird conservation by Birdlife International. It is also the most important migration corridors of southwestern China. From 2005-2014, the research team of ornithology of KIZ, CAS, carried out 16 bird explorations, and recorded 381 bird species. Therefore, combining with the data from available literatures and natural reserve logging, a total of 462 bird species were found in Ailao Mountains.

In this recent study, by using the methods of mist-nets and point-counts, the degree of dissimilarity in species composition between the human-modified and primary forests were examined; and the quantities of total species and exclusive species were present in the human-modified forests were estimated. It was found that species composition differed significantly among the habitat types at different elevations and species turnover among four habitats accounted for most of the total species diversity. Forest interior and insectivore bird species richness in the secondary and firewood forests were also high compared with that in the primary forests. Moreover, some species, e.g., 18 species of the recorded Babblers (Timaliidae), which are very sensitive to disturbance, were only found the human-modified forests.

These results indicate that every habitat in this study was indispensable to maintaining regional bird diversity. The mid-to-low elevation human-modified forests partially alleviate the negative effects of primary forests decreasing on bird diversities. These sub-montane regions are of important meanings in increasing landscape diversity and thereafter offsetting species loss from primary forests.

In summary, this study appreciates the underestimated positive roles of human-modified forests plays in bird diversity protection, suggests that conservation initiatives should be reinforced in both primary and secondary forests.  

The main findings of this study have been published on Bird Conservation International (http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=10318850&fulltextType=RA&fileId=S0959270916000058).

(By Su-Qing Liu)

Contacts:

Prof. Xiao-Jun YANG, KIZ, CAS

E-mail: yangxj@mail.kiz.ac.cn