Population Viability Analysis of Gloydius shedaoensis from Northeastern China:A Contribution to the Assessment of the Conservation and Management Status of an Endangered Species

Shedao pit-vipers(Gloydius shedaoensis) on Snake Island in the Liaoning Province, China, are among the most imperiled species in China. The isolated and unique populations are crucial in the recovery of this endangered species by providing a way for conservation and management. Research based on the ecological simulation tools can evaluate alternative mitigation strategies in terms of their benefits to the populations, which are vital for informed decision-making. In this paper, using the program VORTEX 9.42, we developed a population viability analysis(PVA) for the Shedao pit-viper to:(1) address the extinction likelihood of the population;(2) simulate population dynamics under various environment events, and(3) evaluate the efficacy of current protection and management strategies. Overall, we found the population to be susceptible to the factors of catastrophic events, mortality and environment capacity. The population is recovering slowly at present on account of improvement of habitat and greater food availability. Under the current conditions, the probability of extinction in 100 years is approximately zero. These data coincide with the evidence that the wild population may be arriving at K. Our results strengthen the view that protection and management can create a pronounced effect on populations of this endangered species.

Tree species diversity and stand structure along major community types in lowland primary and secondary moist deciduous forests in Tripura,Northeast India

Tree species diversity and population structure at different community types were described and analyzed for primary and secondary lowland moist deciduous forests in Tripura. Overall 10,957 individual trees belonging to 46 family, 103 genera and 144 species were counted at ≥30 cm DBH （diameter at breast height） using 28 permanent belt transects with a size of 1 ha （10 m × 1000 m）. Four different tree communities were identified. The primary forests was dominated by Shorea robusta （mean density 464.77 trees.ha^-1, 105 species） and Schima wallichii （336.25 trees.ha^-1, 82 species）, while the secondary forests was dominated by Tectona grandis （333.88 trees.ha^-1, 105 species） and Hevea brasiliensis （299.67 trees.ha^-1, 82 species）. Overall mean basal area in this study was 18.01m2.ha^-1; the maximum value was recorded in primary Shorea forest （26.21 m2.ha^-1）. Mean density and diversity indices were differed significantly within four different communities. No significant differences were observed in number of species, genera, family and tree basal cover area. Significant relationships were found between the species richness and different tree population groups across the communities. Results revealed that species diversity and density were increased in those forests due to past disturbances which resulted in slow accumu- lation of native oligarchic small tree species. Seventeen species were recorded with 〈2 individuals of which Saraca asoka （Roxb.） de Wilde and Entada phaseoloides （L.） Men＇. etc. extensively used in local ethnomedicinal formulations. The present S. robusta Gaertn dominated forest was recorded richer （105 species） than other reported studies. Moraceae was found more speciose family instead of Papilionaceae and Euphorbiaceae than other Indian moist deciduous forests. Seasonal phenological gap in such moist deciduous forests influenced the population of Trachypithecus pileatus and capped langur. The analysis of FIV suggested a slow trend of shifting the population of Lamiaceae group by Moraceae species in secondary T. grandis L. dominated community.

The Lynx and Hare Data of 200 Years as the Nonlinear Conserving Interaction Based on Noether’s Conservation Laws and Stability

We applied n-variable conserving nonlinear differential equations (n-CNDEs) to the population data of the 10-year cycles of Canadian lynx (1821-2016) and the snowshoe hare (1845-1921). Modeling external effects as perturbations to population dynamics, recovering and restorations from disintegrations (or extinctions), stability and survival strategies are discussed in terms of the conservation law inherent to dynamical interactions among species. The 2-variable conserving nonlinear interaction (2CNIs) is extended to 3, 4, ... n-variable conserving nonlinear interactions (n-CNIs) of species by adjusting minimum unknown parameters. The population cycle of species is a manifestation of conservation laws existing in complicated ecosystems, which is suggested from the CNDE analysis as a standard rhythm of interactions. The ecosystem is a consequence of the long history of nonlinear interactions and evolutions among life-beings and the natural environment, and the population dynamics of an ecosystem are observed as approximate CNIs. Physical analyses of the conserving quantity in nonlinear interactions would help us understand why and how they have developed. The standard rhythm found in nonlinear interactions should be considered as a manifestation of the survival strategy and the survival of the fittest to the balance of biological systems. The CNDEs and nonlinear differential equations with time-dependent coefficients would help find useful physical information on the survival of the fittest and symbiosis in an ecosystem.

Functional diversity of Cercidiphyllum japonicum, communities in the Shennongjia Reserve, central China

Functional diversity is significant to ecological processes of plant communities. We analyzed the variation of functional diversity of endangered species, Cercidiphyllum japonicum, communities along an elevational gradient in the Shennongjia Reserve, central China. Sixty plots of 10 9 20 m from 1,350 to 2,050 m were set up and species composition, traits and environmental variables were measured and recorded. These data were analyzed using five functional diversity indices, functional attribute diversity, modified functional attribute diversity, plot based functional diversity, community based functional diversity and Rao＇s functional diversity indices（Rao＇s index）,Functional diversities of C. japonicum communities were rich and varied greatly. Functional diversity declined nonlinearly with increasing elevation. Functional diversity was significantly correlated with species richness and heterogeneity. Elevation was a key environmental variable influencing functional diversity and species diversity. The five functional diversity indices were all effective for measuring functional diversity of communities. Functional diversity can be used as an indicator of conservation efficiency of endangered species such as C. japonicum.

Quantifying landscape linkages among giant panda subpopulations in regional scale conservation

Understanding habitat requirements and identifying landscape linkages are essential for the survival of isolat­ed populations of endangered species.Currently,some of the giant panda populations are isolated,which threat­ens their long-term survival,particularly in the Xiaoxiangling mountains.In the present study,we quantified niche requirements and then identified potential linkages of giant panda subpopulations in the most isolated re­gion,using ecological niche factor analysis and a least-cost path model.Giant pandas preferred habitat with co­nifer forest and gentle slopes(>20 to≤30°).Based on spatial distribution of suitable habitat,linkages were iden­tified for the Yele subpopulation to 4 other subpopulations(Liziping,Matou,Xinmin and Wanba).Their lengths ranged from 15 to 54 km.The accumulated cost ranged from 693 to 3166 and conifer forest covered over 31%.However,a variety of features(e.g.major roads,human settlements and large unforested areas)might act as barriers along the linkages for giant panda dispersal.Our analysis quantified giant panda subpopulation connec­tivity to ensure long-term survival.

Protecting endemic seed plants on the Tibetan Plateau under future climate change: migration matters

Aims Climate change in the near future may become a major threat to high-altitude endemics by greatly altering their distribution.Our aims are to(i)assess the potential impacts of future climate change on the diversity and distribution of seed plants endemic to the Tibetan Plateau and(ii)evaluate the conservation effectiveness of the current National Nature Reserves(NNRs)in protecting the endemic plants in the face of climate change.Methods We projected range shifts of 993 endemic species to the years 2050 and 2070 under two representative concentration pathway scenarios using an ensemble species distribution modeling framework and evaluated range loss,species-richness change and coverage of the current conservation network considering two dispersal scenarios.Important Findings In a full-dispersal scenario,72–81%of the species would expand their distribution by 2070,but 6–20%of the species would experience>30%range loss.Most species would shift to the west.The projected species net richness would increase across the region on average.In a no-dispersal scenario,15–59%of the species would lose>30%of their current habitat by 2070.Severe species loss may occur in the southeastern and the eastern peripheral plateau.Seventeen percent of species ranges are covered by the NNRs on average and may increase in the future if species disperse freely.We found a significant difference of species redistribution patterns between different dispersal scenarios and highlighted the importance of migration in this region.