Diversity and conservation of plant species in dry valleys, southwest China

Abstract

The dry valleys in southwest China harbor a highly varied concentration of endemic plant species. To date, the conservation of the unique ecosystem has been paid attention, whereas conservation for the regional endemic plant species has not been much focused. The dry valleys own approximately 1707 plant species among which, 37.42 % are endemic. The plant species in that dry ecosystem are currently challenged by the climate change and anthropogenic activity. To give insight into the current (and past) status of threatened species and the population conservation management strategies, we investigated the genetic diversities of endemic and endangered plant species in the dry valleys in the last decade, using nuclear or plastid molecular markers. Our data revealed that the plant species in this region have low levels of genetic diversity within populations and strong genetic structure. We thus concluded that strong geography patterns are mainly shaped by complex topography as well as their local habitats. We pointed that it is of importance to incorporate neutral and non-neutral genetic diversity when assessing the status of the endangered species. We suggest more research findings are needed to well understand and ensure regional effective conservation on the plant species occurred in the dry valleys.

Investigating the Genetic Diversity, Population Differentiation and Population Dynamics of Cycas segmentifida (Cycadaceae) Endemic to Southwest China by Multiple Molecular Markers

“…Southwest China is seen as one of the world’s biodiversity hotspots because of its complicated terrain, diversified climates and habitats ( Myers et al, 2000 ). The region possesses an extremely high richness of species and concentrates numerous endemic and endangered plant species ( Zhao and Gong, 2015 ). Climatic oscillations in the Pleistocene led to drastic environmental changes repeatedly, which also substantially influenced the species’ distribution and evolution, even extinction ( Hewitt, 1996 , 2000 , 2004 ; Comes and Kadereit, 1998 ).…”

Genetic diversity and population structure of Vriesea reitzii (Bromeliaceae), a species from the Southern Brazilian Highlands

“…According to Furtado and Menini-Neto (2015) , the particular features of mountainous regions confer them high indices of species richness and cause them to harbor important forest remnants in the form of vegetation islands. However, these ecosystems can be very sensitive to anthropogenic disturbances ( Zhao and Gong, 2015 ). Here, despite the fact that V. reitzii is endemic to the southern region of Brazil and restricted to the MOF, a highly particular mountain environment with high anthropogenic influence, we did not find low levels of genetic diversity in the populations sampled across its geographical range.…”

The effect of small-scale topography on patterns of endemism within islands

“…The effect of large-scale topography, such as mountain ranges, on patterns of species richness, speciation rates, and endemism are increasingly well documented (Thomas et al 2008, Steinbauer et al 2012, Verboom et al 2015, Steinbauer et al 2016, Xing and Ree 2017, but the direct effect of local topography, such as steep-sided barrancos or ravines, is less well understood. In contrast to mountains, deep valleys or barrancos are only rarely discussed as barriers to gene flow (Janzen 1967, Ghalambor 2006, Steinbauer et al 2016, and few studies have considered barranco beds as isolated habitats which are themselves separated from each other by dispersal barriers, creating divergence between resident populations (Zhao and Gong 2015). Barrancos (or ravines) are deep gorges with steep sides and very narrow beds.…”

“…If some barrancos are isolated habitats, then they may have the potential to harbour relatively high levels of endemism. This is true of the valleys in the Hengduan Mountain Region of China: they host a high diversity of plant species, of which 37% are endemic, and some species are endemic to specific valleys (Zhao and Gong 2015). This mechanism is taxon dependent, whereby more vagile species are less affected.…”