Studies On Conservation Genetics Of Sinojackia Hu And Changiostyrax C.T.Chen

The genus Sinojackia Hu and Changiostyrax C.T.Chen (Styracaceae) including only seven species native to China are cuurently in the endangered status due to intensive disturbances. In the present study, the studies on the conservation genetics of Sinojackia Hu and Changiostyrax C.T.Chen were conducted based on our field investigation on the two genera. The main results are highlighted in the following:1. We conducted an extensive field survey of current geographic distribution of their natural range, and in situ and ex situ conservation status of the remnant populations of the two genera. The results showed that in spite of a wide range of natural distribution of the two genera, all species in Sinojackia and Changiostyrax maintained a small number of populations with very small population size, apparently resulting from habitat degradation and population losses. S. xylocarpa and S. rehderiana were extinct in Jiangsu and Jiangxi Province where the type specimen was collected. During the survey, S. xylocarpa was rarely found in Shangcheng and Xinxian counties of Henan Province, and Guangshui and Changyang counties of Hubei Province. In addition, S. rehderiana was aslo extinct in the type specimen site in Nanchang, Jiangxi Province. In past more than 70 years, neither wild populations nor individuals of S. henryi were found since the type specimen was first identified in 1937, suggesting this species may be either a synonym mixed with other Sinojackia species or extinct in the wild. The populations of S. microcarpa were reduced rapidly in wild because of anthropogenic destruction and only two sizeable populations were located in Zhejiang Province. S. sarcocarpa and S. oblongicarpa had only one each population survived in Leshan and Huaihua, respectively, which suggested critically endangered in wild. A possible new taxon was found during the field survey and needs for further taxonomic identification. Most investigated species had small number of populations and low seedling recruitment within each population because of low rate of seed germination. The deforestation by local residents had great impact on the survival of Sinojackia. Therefore, an integrating conservation strategy should be urgently carried out and current in situ and ex situ conservation be rigidly forced in order to conserve the two endangered genera. We also suggest that all seven species should be included in the...