Identification Of Species Priority Conservation Areas In The Three Parallel Rivers Region

The identification of biodiversity priority conservation areas and systematic planning of regional protected-area network are crucial for allocating the limited conservation resources to areas most in need of protection,and thus for cost-efficiently achieving the full biodiversity conservation goals.This is a key strategy for abating the rapid biodiversity loss and realizing the regional sustainable development.The Three Parallel Rivers Region is one of the most biodiversity significant regions in China,and also a well-known global biodiversity hotspot.The identification of prioritsy conservation areas is essential to upgrade the existing reserve system in Three Parallel Rivers Region.However,due to the lack of systematic ecological investigations,species distribution data are rarely used in previous studies of setting priority conservation areas.To fill this knowledge gap,a research priority is to establish the spatial distribution data on endangered and rare species,model their suitable habitats and then identify the priority conservation areas for these speciesThis study selected endangered and rare species of animals and plants as the representative conservation features by using the IUCN species red list,China red data book of animals and plants,wildlife under national protection list and the convention on international trade in endangered species of wild fauna and flora as well as the list of wild plant and animal species with extremely small populations in Yunnan Province,with additional information from the global biodiversity information network and related literatures.The spatial occurrence data were then compiled for the selected species by investigating the related biodiversity databases and published literatures.With the species occurrence data and environmental variables of soil,terrain and climate as inputs,Maxent was used to model the suitable habitat index and then the distribution range for each species was extracted from the suitable habitat index based on a threshold.This study used regular grids of 1 km × 1 km as the planning units.A systematic conservation planning tool Zonation was then applied to generate a conservation-value index layer based on the species distribution data.According to the conservation-value index layer.this study identified three scenarios of species priority conservation areas by applying the 2020 Aichi biodiversity target 11(17%),Yunnan province ecological red line target(31%)and global plant diversity conservation goal(50%).Finally,this study analyzed the spatial patterns of these three scenarios of priority conservation areas,and assessed their coverages for existing nature reserves and the priority conservation areas determined in previous studies.The main results and conclusions are as follows:(1)This study established the spatial distribution data on endangered and rare species,including 4762 occurrence records for 852 plants and 754 occurrence records for 357 animals.The spatial distribution of the occurrences of animals and plants showed a double-peak pattern along the elevation gradient,i.e.,more occurrences were recorded in high and low elevation areas,and mainly concentrated around mountain ranges and great rivers.(2)The Maxent model demonstrated that the distribution of endangered and rare species had a good relationship with the following 12 environmental variables:temperature seasonality,temperature mean diurnal range,radiation index of aspect.isothermality,precipitation annual range,annual mean relative humidity,annual total evaporation,elevation,silt content,clay content,soil depth,soil bulkdensity.Clay and silt content were the primary variables influencing the distribution of animal species,accounting for 24.32%and 17.68%of the relative contributions,and 23.89%and 17,67%of the importance of permutation.Elevation and precipitation annual range were the main influencing variables of plant species distribution,accounting f'or 25.73%and 25.10%of the relative contributions,26.09%and 20.77%of permutation importance.This study modeled the suitable habitats for those species having over 5 occurrences,including 181 occurrences for 29 animals,and 3691 occurrences for 261 plants.The average area under the receiver operating characteristic curve of the training set was 0.91,and the average area under the receiver operating characteristic curve of the test set was 0.78.both were higher than 0.7.This indicates that the Maxent model can be used in this region to predict the suitable habitats for endangered and rare species so as to improve the regional species distribution data.(3)The three scenarios of species priority conservation areas(i.e.,17%,31%and 50%)identified in this study accounted for 37.80%,48.86%and 66.40%of the total area of nature reserves,respectively.The three scenarios accounted for 28.68%,44.95%and 64.62%of the total area of the plant priority conservation areas,and 26.46%,42.35%and 62.83%of the total area of wilderness areas.This study also indentified many additional priority conservation areas that are not recognized in previous studies,which were primarily distributed in northwest Deqin,central Gongshan.west Fugong,Lushui,west and east Binchuan as well as the areas around the nature reserves of Lashihai.Jianhu and Luguhu.