Population characteristics of endangered species Taxus chinensis var. mairei and its conservation strategy in Shanxi, China

Abstract

The conservation of the endemic, endangered, and first-class protected tree species, Taxus chinensis var. mairei (Lem. & H. Lev.) W. C. Cheng & L. K. Fu, is urgent in China. To assist the protection of this important medicinal plant species, the biological and ecological characteristics of its populations were investigated and analyzed in Shanxi. The study area, southeastern Shanxi, is a special region suitable for this species growth and development. The floristic composition, life form spectrum, and species diversity of T. chinensis var. mairei forests reflected the features of both warm-temperate and subtropical regions. Size classes in DBH and static life table analysis showed that the population structure of T. chinensis var. mairei was of the increase-type. Plant density, survivorship, and mortality decreased with increase in age. Distribution patterns of individuals were basically clumped and saplings tended to be distributed randomly. Disturbance from collection of leaves, branches, and stems for medicine was an important factor affecting population structure, dynamics, and distribution. The sex ratio of female/male and the efficiency of sexual reproduction were very low. The main way of reproduction for this species is vegetative propagation. Based on these characteristics, some suggestions, such as establishing nature reserves, improving population structure by cultivation and transplantation, developing seed gardens, and plantations, etc., for the conservation management of T. chinensis var. mairei and its forests in Shanxi are discussed.

Genetic diversity and population structure of the endangered conifer Taxus wallichiana var. mairei (Taxaceae) revealed by Simple Sequence Repeat (SSR) markers

“…Moreover, yews are old relicts undergoing repetitious climatic changes especially Quaternary glaciations, as would lead to loss of range and thus loss of crucial genetic diversity (Hewitt, 2000). Finally, human activities as chopping for the adult lead to serious decreasing of population sizes and deficiency of fertile individuals (Zhang and Ru, 2010). This conclusion was consistent with phylogeographical research for T. wallichiana complex based on cpDNA gene, in which two dominant haplotypes appeared in this variety .…”

“…T. wallichiana var. mairei is a dioecious plant with wind pollination, which also reproduced by vegetative propagation (Yue et al, 2010;Zhang and Ru, 2010). But the 13 studied populations showed relatively moderate genetic diversity (H E ¼ 0.538) at the population level and low genetic differentiation among populations (F ST ¼ 0.159) (Tables 1 and 2).…”

“…T. wallichiana var. mairei is mainly regenerated by cloning reproduction and rarely by seedlings, which maintain population sizes and their genetic characters (Yue et al, 2010;Zhang and Ru, 2010). Many isolated populations were faced with significant inbreeding and genetic drift associated with habitat fragmentation, which was also supported by the fixation index (F IS ) and the HWE analysis.…”

“…mairei possess highly economic values, especially extracting taxol as anticancer drug (Zhang et al, 2009). This yew is faced with danger of extinct because of severe felling and peeling, besides habitat destruct and its biological characters (Zhang et al, 2009;Zhang and Ru, 2010). Although yew had been listed as the first class of protected plant, unlawful felling still frequently occurred in mountainous area.…”

Influence of initial light intensity and deer browsing on Taxus baccata saplings: a six years field study

“…Threats and interest in the pharmaceutical industry are the reason for conservation and restoration programs of yew in many regions of the world (Smith and Cameron 2002;Zhang and Ru 2010;Farris et al 2012;Katsavou and Ganatsas 2012). European yew is a shade-tolerant species, and although it often grows well in the full sun (Thomas and Polwart 2003;Perrin and Mitchell 2013).…”