Atmospheric nitrogen deposition and precipitation as an important phenomenon of global climate change have a great impact on grassland ecosystems. However, little is known about how the soil ammonia-oxidizing microorganisms respond to the both changes. Ammonia oxidization is a crucial step in the soil nitrification and greatly influenced by soil nitrogen availability. We used PCR and DGGE (denaturing gradient gel electrophoresis) approaches to investigate the responses of AOB (ammonia-oxidizing bacteria) 16S rRNA and AOA (ammoniaoxidizing archaea) amoA genes to nitrogen and water input in Stipa baicalensis steppe, Inner Mongolia, northern China. After two years of nitrogen and water addition treatment, it was found that PNA (potential nitrification activity) was greatly enhanced by lower N fertilization treatment under water addition and higher N fertilization under nowater addition, while it decreased markedly in higher N fertilization under water addition. The community structure of AOB responded more sensitively to N fertilization and water input than AOA, resulting in the significantly decreased diversity in the AOB community along with a higher N fertilizer rate, but an obvious increase in the AOA community, demonstrating the active growth of AOA in higher N fertilization soils. Phylogenetic analysis showed that AOB communities were dominated by Nitrosospira clusters3, 4 and Nitrososmonas clusters 6 under water addition and Nitrosospira culsters 1, 3 and 4 and under no-water addition, while AOA communities were grouped into Crenarchaeote clusters 1, 2 and 5 under no-water addition and Crenarchaeote clusters 1, 2 and water lineage under water addition. The differences between the two water addition regimes strongly suggest that water input acts as an important role in shifting AOA and AOB communities. Moreover, in contrast to the AOA, the diversity of AOB was negatively correlated with total N, NH₄ , NO₃^- and pH under water addition, implying a significant N fertilization and water effect on shaping AOA and AOB communities. In conclusion, our studies suggested that N fertilization and water addition and their composite effects had significantly changed AOB and AOA communities, meanwhile, AOB and AOA communities could develop a desirable complementary mechanism in response to external changes.

Tourist attraction is a very important carrier of tourism activities. A-grade tourist attraction is a national standard of comprehensive evaluation about tourist attractions quality and grade in China. In this paper, spatial structure of 2424 national A-grade tourist attractions are investigated by using GIS and quantitative analysis methods, such as nearest neighbor index (NNI), quadrat analysis, Gini coefficient and hot spot clustering. Spatial accessibility of all A-grade tourist attractions was calculated using cost weighted distance method and ArcGIS software. Service range of each tourist attraction at 4A grade and above in China was delimitated based on the cost allocation method. Results show that China's A-grade tourist attractions present aggregate distribution characteristics on the whole, and cultural attractions aggregate distribution is higher than of natural tourist attractions. Above-4A grade quality attractions aggregate distribution is lower than the Below-4A grade tourist attractions; cultural Above-4A grade are significantly greater than the cultural Below-4A grade tourist attractions. A-grade tourist attractions in China's eight districts are aggregate. The spatial distribution uniformity is low. Affected by the degree of economic development and tourism resources endowment, the service range of Above-4A grade attractions is big in West, small in East, big in North, and small in South. First-order hot spots areas were mainly concentrated in the east side of the line formed by Deqen-Alxa Left Banner. The second-order hot spot areas were composed of 11 regions, while the third-order hot spot areas include Beijing, Tianjin, Central Plains and the Yangtze River Delta.

We identified and mapped ecotourism areas in the First Meander of the Yellow River (FMYR) by incorporating tourist preferences, and regional division was also conducted. Considering wetland protection and local natural worship, we identified available ecotourism areas and used GIS to overlay six layers of the criteria to generate a suitability map of available areas. This process incorporated the opinions of 158 tourists to weight each criterion. Available areas were classified into five levels of suitability, with class I being the least suitable for ecotourism and class V being the most suitable. Distance from water area was found to be the most important criterion, and presence of forest to be the least important. The results show that a majority of the FMYR is class II, III or IV. FMYR was further divided into five sub-regions, and it is clear that the particular ecological characteristics and service functions of each sub-region warrant particular development. This study provides useful insights for tourism planners, local managers and visitors.

Reference conditions having no or only minor anthropogenic disturbances, are a basic requirement for ecological studies in rivers. To study ecological impact of a dam, two sites were pre-classified as reference or least disturbed in the Andhi Khola River, Nepal, using Rapid Field Bioscreening (RFB) protocol. Biological (macroinvertebrates) and physico-chemical samples were collected in the month of January and February 2013. Multi-habitat sampling (MHS) was employed in sample collection of macro-invertebrates fauna. Validation of the pre-classified sites was done using several indices viz. Nepalese biotic score (NEPBIOS), Biological monitoring working party (BMWP), Hindu-Kush Himalayan biotic score (HKHBIOS), Hilsenhoff (HILSENHOFF) & National Sanitation Foundation Water Quality Index (NSFWQI). The NEPBIOS, HKHBIOS, HILSENHOFF, RFB & NSFWQI indices predicted the river quality at all two sites as good with quality class II. Only BMWP/ASPT water quality index predicted the river quality at all two sites as Excellent with quality class I. Hence preselected sites with quality of rank II i.e. good qualities were validated as reference sites. The study demonstrated that the multi-metric approach is suitable for application in the monitoring and assessment of rivers where dams are built to produce hydropower.

Based on the functional process of carbon sequestration of forest, we categorize carbon sequestration in two parts: carbon capture and carbon storage. Here, Pinus sylvestris var. mongolica was used to simulate the dynamic changing process of carbon sequestration of forest in a century using tree growth formula and the cost of carbon capture and sequestration. We found that the total carbon captured and stored by 100-year-old P. sylvestris var. mongolica are both 966 kg C tree^-1. On the assumption that the current year is the planting year, the present total carbon sequestration value (capital value) of 100-year-old P. sylvesrtis var. mongolica is 54.78 USD tree^-1 at the discount rate of 3%, with the present total carbon capture value of 18.92 USD tree^-1 and carbon storage value of 35.86 USD tree^-1. The dynamic process of the annual value of carbon capture is illustrated by an upside-down U shape curve, while that of carbon storage service follows an S shape curve. The combination of the dynamic processes of carbon capture value and carbon storage value represent the changing process of carbon sequestration value, which appears to be an S shape curve.

Eco-sensitivity evaluation is the basis for land development and has practical significance to the establishment of environmentally-friendly economic and social development models. Compared to simple geomorphic regions, complex geomorphic regions are limited by a higher number of eco-sensitivity factors under a land exploitation context. Further still, these factors have complicated spatial characteristics and affect each other. Based on published data, we focused on the city of Qinzhou in Guangxi Zhuang Autonomous Region, China and developed an eco-sensitivity assessment system spanning land ecology, water ecology and plant ecology. A systematic comprehensive assessment of all watersheds was done using qualitative classification, spatial quantitative modeling, remote sensing and GIS technology. We were able to group Qinzhou's 273 watersheds into three types: high sensitivity areas, medium sensitivity areas and low sensitivity areas. We propose a limit on land exploitation activities in high sensitivity areas and an ecological security network. The methods utilized here can help determine eco-sensitivity characteristics in complex geomorphic regions and with this knowledge governments will be able to develop robust scientific policy to protect regional ecological security.

We used a FluorCam portable chlorophyll fluorescence imaging system to measure QY-max (the maximum light quantum yield, Fv/Fm, the largest light quantum efficiency of PS II) of submerged plants in wetlands of Baisha Lake and Changhu Lake, Jiangxi Nanjishan Wetland National Nature Reserve, in winter 2013. Specifically, we measured ΦPS II (PS II actual quantum efficiency), qP (photochemical quenching) and corresponding fluorescence images. Using the visual method and sampling sites method to obtain coverage, richness and abundance of submerged plants, and determined nutrient levels in water. The results show that the QY-max of Hydrilla verticillata and Vallisneria natans in Baisha Lake ranged from 0.48 to 0.68 and 0.52 to 0.71, respectively: the ΦPS II of these two species ranged from 0.32 to 0.58 and 0.20 to 0.46, respectively. The two plants had similar photosynthetic efficiency. The QY-max of Nymphoides peltatum and V. natans in Changhu Lake ranged from 0.66 to 0.77 and 0.19 to 0.68, respectively; the ΦPS II of these two species ranged from 0.26 to 0.48 and 0.22 to 0.43, respectively. The observed higher photosynthetic efficiency of N peltatum suggests it is more likely to become the dominant species. In Baisha Lake, the frequency of occurrence of plants was: H. verticillata, 90%; V. natans, 93.3%; Najas minor 26.7%, and Potamogeton franchetii 10%. In Changhu Lake, the frequency of N. peltatum was 86.7%, V. natans was 16.7%, and N. minor was 56.7%. The overall frequency of submerged plants living in Baisha Lake was much higher than that of submerged plants living in Changhu Lake, with different species dominating the two lakes. According to comprehensive analysis and comparison of trophic levels, biodiversity and photosynthetic fluorescence characteristics in the two lakes, eutrophication of Baisha Lake was higher than for Changhu Lake; and H. verticillata and V. natans were the dominant species, with similar photosynthetic activity. Conversely, in Changhu Lake, N. peltatum and V. natans were the dominant species, but the photosynthetic activity of N. peltatum was higher than V. natans. Differences in eutrophication levels in different water bodies in the Nanjishan Wetland and differing ecological niches of submerged plant species are characteristic of this system.

Research on coke price forecasting is of theoretical and practical significance. Here, the Kalman filtering algorithm was used to analyze the price of coke. As the only state variable, the historical coke price is sorted out to build the state space model. The algorithm makes use of innovation composed of the difference between observed and predicted values, and allows us to obtain the optimal estimated value of the coke price via continuous updating and iteration of innovation. Our results show that this algorithm is effective in the field of coke price tracking and forecasting.