Understanding population history and genetic structure are key drivers of ecological research. Here, we studied two highly fragmented and isolated populations (Xiaoxiangling and Daxiangling) of giant pandas (Ailuropoda melanoleuca) at the extreme southwestern edge of their distribution. This area also contains the Dadu River, national road 108 and various human infrastructure and development, providing an ideal region in which we can identify the effects of different barriers on animal movements. We used partial mitochondrial control region (mtDNA) and nine microsatellite loci (nuclear DNA) data derived from 192 faecal and one blood sample collected from the wild. We found 136 genotypes corresponding to 53 unique multilocus genotypes and eight unique control region haplotypes (653 bp). Significant genetic boundaries correlated spatially with the Dadu River (K = 2). We estimate that a major divergence took place between these populations 26,000 years bp, at around the similar time the rock surface of valley bottom formed in Dadu River. The national road has resulted in further recent population differentiation (Pairwise F(S) on mtDNA and nuclear DNA) so that in effect, four smaller sub-populations now exist. Promisingly, we identified two possible first-generation migrants and their migration paths, and recommended the immediate construction of a number of corridors. Fortunately, the Chinese government has accepted our advice and is now planning corridor construction.
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http://dx.doi.org/10.1111/j.1365-294X.2011.04999.x | DOI Listing |
Sci Total Environ
December 2024
Sichuan Highway Planning, Survey, Design and Research Institute Ltd., Chengdu 610041, China.
Debris flows are a prevalent mountain hazard that poses severe risks to human life and property. Debris-flow hazard assessments at the regional scale are vital for risk management, which establish spatial associations between debris flows and their influencing factors based on specific evaluation units. Different spatial scales of evaluation units can influence the spatial attributes and associations obtained by statistics, and further affect the accuracy of hazard assessments.
View Article and Find Full Text PDFAnimals (Basel)
April 2024
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
This study describes a novel species of (Squamata, Agamidae) from the lower valley of the Dadu River of the Sichuan Province of Western China based on its distinct morphological features and molecular evidence. sp. nov.
View Article and Find Full Text PDFSci Rep
May 2024
Institute of Water Resources and Hydroelectric Engineering, Xi'an University of Technology, Xi'an, 710048, China.
The wide application of rotating machinery has boosted the development of electricity and aviation, however, long-term operation can lead to a variety of faults. The use of different measures to deal with corresponding malfunctions is the key to generating benefits, so it is significant to carry out the fault diagnosis of rotating machinery. In this work, a test bench for single-span rotor bearings was established, three faults, including spindle bending, spindle crack without end loading and spindle crack with end loading, are experimental analyzed with basic mechanical response.
View Article and Find Full Text PDFPLoS One
April 2024
College of Water Resource and Hydropower, Sichuan University, Chengdu, Sichuan, P. R. China.
Debris flow is a typical natural disaster in the middle reaches of the Dadu River, Southwest China. Field physical model tests were conducted to reveal the mechanism of river blocking by debris flow in the middle reaches of the Dadu River. The dynamic processes of riHver blocking by debris flows were revealed, and based on which three typical river-blocking modes of debris flow are observed, i.
View Article and Find Full Text PDFSci Rep
March 2024
Institute of Water Resources and Hydroelectric Engineering, Xi'an University of Technology, Xi'an, 710048, China.
The radiator with heat transfer capability is able to guarantee the stable operation of hydro generator set, while the long-term and continuous scouring on radiator pipes by cooling medium will lead to thinning or even perforation of pipe wall, which triggers wall failure. This paper analyzes and predicts the failure mechanism of radiator's pipe wall, and investigates the effects of water flow velocity, sand content and sand particle size on erosion damage of radiator pipe by establishing a test bench for pipe erosion. The results show that the increase of above parameters will lead to the increasing erosion rate, especially when the sand content is 1%, the velocity is 8 m/s and the sand particle size is 0.
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