Spatiotemporal Evolution of Ecological Quality in Alpine Freshwater Lake Nature Reserves in the Past 20 Years

The Caohai Nature Reserve is one of the three major plateau freshwater lakes in China.Since the 1950s,human activities such as land reclamation and population relocation have greatly damaged Caohai.A rapid evaluation of the spatiotemporal evolution trend of the ecological quality of the Caohai Nature Reserve is significant for the maintenance and construction of the ecosystem in this area.The research is based on the Google Earth Engine(GEE)remote sensing cloud computing platform.Landsat TM/OLI images from May to October in five time periods:2000-2002,2004-2006,2009-2011,2014-2016,and 2019-2021 were obtained to reconstruct the optimal cloud image set by averaging the images in each time period.By constructing four ecological indicators:Greenness(NDVI),Wetness(Wet),Hotness(LST),and Dryness(NDBSI),and using Principal Component Analysis(PCA)method to obtain the Remote Sensing Ecological Index(RSEI)for the corresponding years,the spatiotemporal variation of ecological quality in the Caohai Nature Reserve over 20 years was analyzed.The results indicate:①the mean value of RSEI increased from 0.460 in 2000-2002 to 0.772 in 2019-2021,a 67.83%increase,indicating a significant improvement in the ecological quality of the reserve over the 20 years;②from the perspective of functional zoning of the Caohai Nature Reserve,the ecological quality of the core area showed a degrading trend,while the ecological quality of the buffer zone and experimental zone significantly improved;③with the implementation of ecological restoration projects,the ecological quality of the reserve gradually recovered and improved from 2014 to 2021.The trend of RSEI value changes is well correlated with human interventions,indicating that the PCA-based RSEI model can be effectively used for ecological quality assessment in lake areas.

Population Density and Habitat Utilization of Ibex(Capra ibex)in Tomur National Nature Reserve,Xinjiang,China

Surveys was conducted to study the population density and habitat utilization of the ibex （Capra ibex） in Tomur National Nature Reserve during October- December 2005. The results are as follows： ① The mean group size of the ibex in Tomur Nature Reserve is 8.43 and the population density is 269.76/100 km^2; ② The ibex prefer areas with steep slope （between 30° -45°）, broken substrates and cliffs nearby （ 〈 100 m）. They avoid grasslands and fiat hillsides; ③The probable reason for this habitat selection is serf-protection.

POPULATION AND CONSERVATION OF BLACK CRESTED GIBBONS ( Hylobates concolor jingdongensis ) IN WULIANG NATURE RESERVE,JINGDONG,YUNNAN

Population estimates of black crested gibbons in Wuliang Nature Reserve,Jingdong,Yunnan,China,with two techniques,average group density total area and average home rang forest coverage,produced quite similar results.The population was estimated around 115 groups in the Reserve.The paper also discussed the conservation problems of the Reserve.At present,the main threat to the gibbons is habitat fragmentation and population isolation.Thus,it is urgent to prohibit hunting and protect the habitat and forest corridors or habitat bridges.

Characteristics of natural Japanese yew population in Muling Nature Reserve of Heilongjiang Province,China

The scalar of Japanese yew （Taxus cuspidata） population and the relationship between individual distribution and site factors were analyzed according to investigating data in 74 sample belts with a total sampled area of 436.872 hm2 in Muling Nature Reserve. The result showed that the distribution rules of Japanese yew population were correlated to elevation, slope position, slope aspect and slope gradient. The optimal distribution range in elevation for the natural Japanese yew population is at the attitudes of 700-800 m. The amounts of Japanese yew individuals on shady slope were more than those on sunny slope. On top slope and mid-slope, the individual amounts of Japanese yew are more than those on toe slope. Most of Japanese yew individuals occurred on slope gradient of less than 15. The scalar of the population was decreased with the slope gradient increasing.

Analysis of Forest Landscape Pattern in Nanling National Nature Reserve,Guangdong

[Objective] The study was to analyze the forest landscape in Nanling Na- tional Nature Reserve to provide information for the protection of local forest ecosys- tems. [Method] With the documents of 1：10 000 topographic maps, updated Forest Resource Inventory Data, based on the GIS platform and Fragstats software, the paper analyzed the patterns and heterogeneity of forest landscapes by adopting the landscape ecological theory and the method of landscape index. [Result] The forest landscape types, in terms of area occupation from large to small, are in the order of evergreen broad-leaved forest, coniferous mixed forest, evergreen and deciduous broad-leaved mixed forest, shrubs, mixed needle leaf forest, suitable land for forest deciduous broad-leaved forest and non-forest. [Conclusion] Overall, the Reserve had maintained sufficient forest landscape diversity with a low level fragmentation. The distribution of various types of forest landscape was extremely uneven, dominated by several types such as evergreen broad-leaved forest, coniferous forest, etc.

On the Biomass of Four Major Tree Species in Vegetation Restoration Pattern Area of Beichuan Nature Reserve

In the experiment, by taking Quercus engleriana Seem., Betula albo- sinensis Burk., Abies faxoniana Rehd. and Fargesia rufa Yi, in the vegetation restoration pattern area of Beichuan Nature Reserve as the research objects, the study on the biomass models, the biomass distribution law of single plant and the growth rule of every organ of the four tree species was made. The results indicated that in the compositions of all of the species, the proportion of trunk biomass was the highest, while that of trunk biomass was the lowest, the proportions of branch and root biomasses varied depending on species; in the comparison of correlativity between the proportions of biomasses of all nutrition organs and biomass of single plant, the relations were generally significant, the tree trunks were positively related while the roots were negatively related; the proportion of trunk biomass of all species was significantly and negatively related to the proportions of leaf and branch biomasses, while the biomass of leaves was significantly and positively related to the biomass of branches.

Remote Sensing Monitoring and Analysis of Responses of Ma Yang Francois Nature Reserve to Impoundment of Pengshui Reservoir

The ecological environmental changes of Francois langur natural reserve was monitored during Pengshui Reservoir construction and influence of reservoir fil-ing on the habitat of the natural reserve was analyzed to provide the scientific basis and basic data for scientific evaluation and protection of original ecological environ-ment of the natural reserve and Francois langur’s habitat, and vegetation recover. The results showed that 4.8 hm2 of the nature reserve was submerged after reser-voir fil ing, which occupied for 0.1% of total area of the natural reserve only. The main influence area was in the submerged area of Hongdu River basin. The water level rise resulted in partial changes in land utilization and soil erosion, which indi-cates that reservoir fil ing has insignificant effect on ecological environment of the whole natural reserve.

Characteristics and the Issue of Eco-safety for the Plant Biodiversity in Longtan Nature Reserve

The characteristic and status quo of plant biodiversity in Longtan Nature Reserve was evaluated from the three aspects of species diversity, genetic diversity and ecosystem dioversity. And the primary eco-safety influencing factors for plant biodiversity in Longtan nature reserve were put forward. The results show that the plant species in Longtan Nature Reserve was abundant, including 2 821 species of vascular bundle plants belonging to 1029 genera, 205 families. The main problems influencing eco-safety included the destruction of endangered wild plants and exotic species invasion.

An Observation of Franois' Langurs Using Caves at Mayanghe National Nature Reserve, Guizhou, China

The utilization of caves is a rather rare phenomenon in nonhuman primates, found almost exclusively in those members of the genus Trachypithecus that share a preference for forest on limestone （karst） hills in Vietnam and southern China. Here we report a new case of usage of caves as overnight sleeping shelters by Franqois＇ or black langurs （Trachypithecusfraru;oisi） at Mayanghe National Nature Reserve in Yanhe County, Guizhou Province, China. We tentatively address three possible hypotheses that may account for the use of caves in Francois＇ langurs at Mayanghe： shelter against climatic conditions, acquisition of minerals and protection from predators. utilization

Assessment of habitat suitability of the snow leopard (Panthera uncia) in Qomolangma National Nature Reserve based on MaxEnt modeling

Habitat evaluation constitutes an important and fundamental step in the management of wildlife populations and conservation policy planning. Geographic information system （GIS） and species presence data provide the means by which such evaluation can be done. Maximum Entropy （MaxEnt） is widely used in habitat suitability modeling due to its power of accuracy and additional descriptive properties To survey snow leopard populations in Qomolangma （Mt. Everest） National Nature Reserve （QNNR）, Xizang （Tibet）, China, we pooled 127 pugmarks, 415 scrape marks, and 127 non-invasive identifications of the animal along line transects and recorded 87 occurrences through camera traps from 2014-2017. We adopted the MaxEnt model to generate a map highlighting the extent of suitable snow leopard habitat in QNNR. Results showed that the accuracy of the MaxEnt model was excellent （mean AUC=0.921）. Precipitation in the driest quarter, ruggedness, elevation, maximum temperature of the warmest month, and annual mean temperature were the main environmental factors influencing habitat suitability for snow leopards, with contribution rates of 20.0%, 14.4%, 13.3%, 8.7%, and 8.2% respectively The suitable habitat area extended for 7 001.93 km^2, representing 22.72% of the whole reserve. The regions bordering Nepal were the main suitable snow leopard habitats and consisted of three separate habitat patches Our findings revealed that precipitation, temperature conditions, ruggedness, and elevations of around 4 000 m a.s.I, influenced snow leopard preferences at the landscape level in QNNR. We advocate further research and cooperation with Nepal to evaluate habitat connectivity and to explore possible proxies of population isolation among these patches. Furthermore, evaluation of subdivisions within the protection zones of QNNR is necessary to improve conservation strategies and enhance protection.

Effect of Environmental Gradients on the Quantity and Quality of Fallen Logs in Tsuga longibracteata Forest in Tianbaoyan National Nature Reserve, Fujian Province,China

We investigated the quantity and quality 0f fallen l0gs in different Tsuga l0ngibracteata f0rest c0mmunities in the Tianba0yan Nati0nal Nature Reserve. We used redundancy analysis t0 determine the spatial distributi0n 0f fallen l0gs in the different f0rest c0mmunities and t0 analyze the relati0nships am0ng stand structure, t0p0graphic fact0rs and human disturbance. The v0lume, c0vered area, mean l0g length and number 0f fallen l0gs differed significantly am0ng f0rest types （P 〈 0.05）, but mean diameter at breast height sh0wed n0 significant difference （P 〉 0.05）. The l0g v0lume and c0vered area in different f0rest types sh0wed the f0ll0wing trend： T. l0ngibracteata pure f0rest 〈 T. l0ngibracteata ＋ Olig0staehyum scabrifl0rur 〈 T. l0ngibraeteata ＋ hardw00d 〈 Rh0d0dendr0n simiarum ＋ T. l0ngibraeteata 〈 T. l0ngibraeteata ＋ Phyll0stachys heter0cycla pubescens. The spatial distributi0n patterns 0f l0gs quantity and quality indicated that l0g v0lume and c0vered area were str0ngly affected by envir0nmental fact0rs in the f0ll0wing 0rder： human disturbance 〉 elevati0n 〉 sl0pe p0siti0n 〉 b0le height 〉 tree height 〉 sl0pe aspect 〉 density 〉 basal area 〉 sl0pe gradient. The relative c0ntributi0n 0f envir0nmental variables 0n the t0tal variance was t0p0graphy （76%） 〉 disturbance （42%） 〉 stand structure （35%）. T0p0graphy and disturbance c0mbined explained 8.2% 0f the variance. Fallen l0~s auantitv and aualitvwere negatively related t0 elevati0n and sl0pe p0siti0n, and p0sitively ass0ciated t0 human disturbance. The l0g v0lume decreased fr0m n0rthern t0 s0uthern sl0pes. Envir0nmental fact0rs had the highest impact 0n class I （slightly decayed）, and l0west impact 0n class V （highly decayed）.

Evaluating Conservation Effectiveness of Nature Reserves Established for Surrogate Species:Case of a Giant Panda Nature Reserve in Qinling Mountains,China

Many nature reserves are established to protect the habitat needs of particular endangered species of interest but their effectiveness for protecting other species is questionable.In this study,this effectiveness was evaluated in a nature reserve network located in the Qinling Mountains,Shaanxi Province,China.The network of reserves was established mainly for the conservation of the giant panda,a species considered as a surrogate for the conservation of many other endangered species in the region.The habitat suitability of nine protected species,including the giant panda,was modeled by using Maximum Entropy(MAXENT)and their spatial congruence was analyzed.Habitat suitability of these species was also overlapped with nature reserve boundaries and their management zones(i.e.,core,buffer and experimental zones).Results show that in general the habitat of the giant panda constitutes a reasonable surrogate of the habitat of other protected species,and giant panda reserves protect a relatively high proportion of the habitat of other protected species.Therefore,giant panda habitat conservation also allows the conservation of the habitat of other protected species in the region.However,a large area of suitable habitat was excluded from the nature reserve network.In addition,four species exhibited a low proportion of highly suitable habitat inside the core zones of nature reserves.It suggests that a high proportion of suitable habitat of protected species not targeted for conservation is located in the experimental and buffer zones,thus,is being affected by human activities.To increase their conservation effectiveness,nature reserves and their management zones need to be re-examined in order to include suitable habitat of more endangered species.The procedures described in this study can be easily implemented for the conservation of many endangered species not only in China but in many other parts of the world.

Nest-site selection pattern of Grus japonensis in Zhalong Nature Reserve of northeast China

Nest-site selection patterns of Red-crowned cranes（Grus japonensis） and the effects of environmental variables were studied during the years of 2002-2008 in Zhalong Nature Reserve,Qiqihar city,northeast China.The nest-site selection pattern of Red-crowned cranes included two orders and three choices：the choice of nest-site habitat type within the macro-habitat order,nest zone selection and nest-site micro-habitat selection within the micro-habitat order.Various habitats（such as Carex swamps and reed fire districts） can be selected as the nest sites for Red-crowned cranes,of which reed swamps（93.15%） are given a preference.Factor Analysis reveals that the micro-habitat selection are affected by four main factors：fire,security（concealment /disturbance）,incubation（conditions,nest-material）,and food.Further analysis reveals that Red-crowned cranes have certain adaptability to the changes of nesting habitat quality in the Zhalong wetlands.In conclusion,fire,reeds,and water were the most important variables for nest-site habitat selection of Red-crowned Cranes in Zhalong Nature Reserve.

Estimation on Aesthetic Value of Tourist Landscapes in a Natural Heritage Site:Kanas National Nature Reserve,Xinjiang,China

Most world natural heritage sites are designated partly by reason of their prominent aesthetic values in accordance with Article Ⅶ of World Natural Heritage Convention.In this paper, the aesthetic values of Kanas National Nature Reserve, which has potential for such designation, was analyzed quantitatively using scenic beauty estimation(SBE).The landscapes of 19 representative scenic spots in the Kanas National Nature Reserve in summer and autumn were selected as the objects of evaluation.The contributions of different landscape factors to the aesthetic value of the Kanas National Nature Reserve were revealed using a multivariate quantitative model.The main factors affecting the aesthetic value were waterscapes, vegetation, mountains, folk culture and the tourist environment.The t-test and F-test results are extremely significant.According to the results, some suggestions were given for conserving the landscapes in the Kanas National Nature Reserve.

Impacts of the Wenchuan Earthquake on the Giant Panda Nature Reserves in China

The Wenchuan Earthquake that occurred in May of 2008 caused damages to large areas of Sichuan,Gansu,and Shaanxi provinces in China.Reports from local governments and related management agencies show that the giant panda nature reserves in the earthquake-hit areas were heavily damaged.Our estimates in this paper of the impacts of the earthquake on the giant panda in the earthquake-hit areas were made based on the interpretation of remote sensing images and information collected by field survey.A rapid assessment method was designed to estimate the damages of the earthquake on giant panda habitats.By using visual interpretation methods,we decoded the remote sensing images of the disaster area in the 49 giant panda nature reserves.Research results showed that the Wenchuan Earthquake and the succeeding secondary geological disasters caused great damages to the giant panda nature reserves and disturbed the normal life of the giant pandas there (e.g.,landscape fragmentation increased significantly).Undoubtedly,the life of the giant pandas there was affected.However,although the earthquake caused certain impacts on the giant pandas,it did not really threat their survival.Even so,we still strongly advocate for protection of the giant pandas,and have prioritized a couple of measures to be taken to restore the giant panda nature reserves in the earthquake-hit areas.

Rhizosphere and bulk soil enzyme activities in a Nothotsuga longibracteata forest in the Tianbaoyan National Nature Reserve,Fujian Province,China

The rhizosphere, distinct from bulk soil, is defined as the volume of soil around living roots and influenced by root activities. We investigated protease, invertase, cellulase, urease, and acid phosphatase activities in rhizosphere and bulk soils of six Nothotsuga longibracteata forest communities within Tianbaoyan National Nature Reserve, including N. longibracteata ＋ either Phyllostachys pubescens, Schima superba, Rhododendron simiarum, Cunninghamia lanceolata, or Cyclobalanopsis glauca, and N. longibracteata pure forest. Rhizosphere soils possessed higher protease, invertase, cellulase, urease, and acid phosphatase activities than bulk soils. The highest invertase, urease, and acid phosphatase activities were observed in rhizosphere samples of N. longibracteata ＋ S. superba. Protease was highest in the N. longibracteata ＋ R. simiarum rhizosphere, while cellulase was highest in the pure N. longibracteata forest rhizosphere. All samples exhibited obvious rhizosphere effects on enzyme activities with a significant linear correlation between acid phosphatase and cellulase activities （p 〈 0.05） in rhizosphere soils and between protease and acid phosphatase activities （p 〈 0.05） in bulk soils. A principal component analysis, correlating 13 soil chemical properties indices relevant to enzyme activities, showed that protease, invertase, acid phosphatase, total N, and cellulase were the most important variables impacting rhizosphere soil quality.

Economic Value Evaluation of Wetland Service in Yeyahu Wetland Nature Reserve,Beijing

Based on multi-source data,this paper evaluated the economic value of ecological services in the Yeyahu Wetland Nature Reserve,Beijing,China.The ecological services of wetland included gas regulation,water quality im-provement,biodiversity maintenance,erosion control,water supply,recreational opportunity,raw material supply and existence value.Multiple conventional evaluation methods were used to calculate the value of eight wetland services.The results showed that significant values came from biodiversity maintenance and recreational opportunity.The main reasons were as follows.Firstly,Yeyahu Wetland Nature Reserve was the habitat for migrant birds,and government had payed more efforts to protect precious birds.Secondly,the population is large in Beijing.People enjoyed going outside and enjoyed the natural and artificial wetland scenes.At the same time,most people were prepared to pay for wetland conservation.The decline of vegetation cover made the economic value of erosion control the lowest.While the shrink of water resource and the deteriorative water quality caused the economic value of water supply lower.The evaluation results could help decision-makers understand the present status of the Yeyahu Wetland Nature Reserve and provide a scientific basis for strategic decision.

Vegetation change in the Mt. Qomolangma Nature Reserve from 1981 to 2001

Based on the NOAA AVHRR-NDVI data from 1981 to 2001, the digitalized China Vegetation Map （1：1,000,000）, DEM, temperature and precipitation data, and field investigation, the spatial patterns and vertical characteristics of natural vegetation changes and their influencing factors in the Mt. Qomolangma Nature Reserve have been studied. The results show that： （1） There is remarkable spatial difference of natural vegetation changes in the Mt. Qomolangma Nature Reserve and stability is the most common status. There are 5.04% of the whole area being seriously degraded, 13.19% slightly degraded, 26.39% slightly improved, 0.97% significantly improved and 54.41% keeping stable. The seriously and slightly degraded areas, which mostly lie in the south of the reserve, are along the national boundaries. The areas of improved vegetation lie in the north of the reserve and the south side of the Yarlung Zangbo River. The stable areas lie between the improved and degraded areas. Degradation decreases with elevation. （2） Degeneration in the Mt. Qomolangma Nature Reserve mostly affects shrubs, needle-leaved forests and mixed forests. （3） The temperature change affects the natural vegetation changes spatially while the integration of temperature changes, slopes and aspects affects the natural vegetation change along the altitude gradients. （4） It is the overuse of resources that leads to the vegetation degeneration in some parts of the Mt. Qomolangma Nature Reserve.

Coupling Relationship Analysis on Households′ Production Behaviors and Their Influencing Factors in Nature Reserves:A Structural Equation Model

A households′production behavior directly influences the quality of the environment and determines the successful development of nature reserves.Meanwhile,the households′production behaviors are complicated by interrelated factors,such as protection attitudes,resource endowment,and family wealth.This research evaluated households near the Crested Ibis National Nature Reserve in Shaanxi Province,acquiring data from 436 households around Yang County and Ningshan County in the south slope of Qinling Mountains,China.Based on the collected data,we developed a structural equation model to evaluate the coupling relationships among households′ protection attitudes,production behaviors,resource endowment,and family wealth.The results showed that:1) households with great resource endowment had more negative attitudes,probably due to their greater protection costs;2) the households with higher education levels had worse protection attitudes;3) the households with more family wealth were likely to use fewer fertilizers,pesticides,and firewood;4) the households with more resource endowment showed less production and management behaviors;5) the enhancement of households' attitudes improved production behaviors to protection the environment,but the effects were not statistically significant.Our results provide a basis for the government's protection policy making,exploring the effective management measures that are beneficial for both nature reserve management and community development.

Management Philosophy and Practices of Habitat Conservation for Jiuzhaigou Nature Reserve, Sichuan, China

Starting from the pressure on habitat of Jiuzhaigou Nature Reserve broughtabout by traveling activity, this paper puts forward such philosophy of community co-management ofconservation-based tourism development for Jiuzhaigou Nature Reserve. According to this philosophy,emphasis is laid on the analysis of the mission of habitat protection, functional division, habitatmaintenance, community construction, scientific study and management organization system. The studyshows that the close relation and significance of rights and interests shared between nature reserveand residents in community, as well as the value of community co-management philosophy ofconservation-based tourism development in sustainable management of nature reserve, have set anexemplary example for other nature reserves.