[Influence of road on breeding habitat of Nipponia nippon based on MaxEnt model]. / 基于MaxEnt模型的道路对朱鹮繁殖地的影响.

Quantitative study on effects of roads on suitable breeding habitats of wildlife is one of topics that need in-depth research in road ecology. Crested ibis (Nipponia nippon), a first class nationally protected bird species, is the species of interest in this research. Using the Maximum Entropy Models (MaxEnt) in the Species Distribution Model (SDM) toolbox of ArcGIS, autocorrelation of environmental variables were analyzed and environmental variables with r>0.8 were removed. Ten environmental variables were chosen as impact factors for the breeding habitat of crested ibis, including mean temperature of coldest quarter, landscape type, normalized difference vegetation index(NDVI), slope, aspect, distance to waters, distance to paddy field, distance to high-grade roads (expressway, national way, provincial way), and distance to low-grade roads (country road). By analyzing the contribution rate of each environmental variable, the results showed that the mean temperature of coldest quarter, landscape type, distance to paddy field, and distance to high-grade roads were the main factors determining breeding habitat of crested ibis. The suitable distribution of crested ibis' nesting area was under the following scenarios: variable road present (scenario1), high-grade road absent (scenario2), and low-grade road absent (scenario 3). The results showed that the presence of roads affected suitable nesting areas of crested ibis with high-grade roads showing a larger influence than low-grade roads. The presence of high-grade roads and low-grade roads decreased the suitable nesting areas of crested ibis by 66.23 and 35.69 km2, respectively. The crested ibis preferred to nest in areas distant from high-grade roads, with an average road avoidance distance of 1500 m. This study was of great significance for formulating management measures to protect crested ibis and provide a reference for quantitative assessment on impacts of engineering and construction projects on wildlife.

[Spatio-temporal change of sand-fixing function and its driving forces in desertification control ecological function area of Hunshandake, China].

Soil erosion is an important ecological and environmental problem in Hunshandake Desert, and the sand-fixing function determines the degree of ecological security in the entire region. In order to clarify the situation of windbreak and sand fixation in Hunshandake area, and to guide the prevention and treatment of desertification on regional scale, based on the meteorological and remote sensing data, this paper quantitatively analyzed the temporal and spatial pattern of windbreak and sand fixation ability between 2000-2010 by the revised wind erosion equation (RWEQ) model, meanwhile, the driving forces for each county ( or banner) in the functional zone were analyzed with the method of principal component analysis. The results showed that there was a fluctuation of the sand fixing capacity in Hunshandake over time, generally rendering a decline trend. The coniferous forest and grassland had strong windbreak and sand fixation capacity in unit area among the various land categories. In terms of spatial distribution, the windbreak and sand fixation function in western and southeastern region was weak and needed to be strengthened with ecological restoration efforts. Through the study of the social driving forces of each administrative region in the function zone, there were 3 main social driving forces of soil erosion in the administrative functions: the intensity of input-output, the level of economic development and the level of agriculture-husbandry development.

[Ecosystem service and economic valuation in the upper reaches of Xin' an River, Anhui, China for mitigating phosphorus nonpoint source pollution].

A model of phosphorus purification in a watershed was established based on the export coefficient and purification index of phosphorus in different types of land cover. The model was employed to simulate the economic value of the ecosystem service with the expected water quality standard and marginal cost of pollutant purification of the upper reaches of Xin' an River of Anhui, China. The results revealed that from 2000 to 2010, some farmland outside the Tunxi, Jixi, Shexian, Yixian and Xiuning was converted to built-up land. The total amount of phosphorus exported to the upper Xin' an River decreased a little, and the main source of phosphorus pollution was farmland and built-up land. More than half of the exported phosphorus was efficiently purified by different types of land cover via flow accumulation. The pattern of purification and export of highly concentrated phosphorus showed the same trend which occurred in the northern part of the watershed including the Yangzhi River, Fengle River and Hengjiang River. Forestland and grassland did not efficiently purify phosphorus in the watershed owing to the irrational distribution of existing land cover. The total service value was 3.80 and 3.31 million Yuan in 2000 and 2010, respectively.

[Responses of ecosystem services value to land use change in national nature reserves in Xinjiang, China].

With GIS and RS technology, characteristics of land use change and ecosystem services value of different years in six national nature reserves in Xinjiang, China were analyzed with remote sensing image of the year 2000-2010. Results showed that the area of water body and grassland decreased while the area of forest, farmland, wetland, unused land and construction land increased in 2000-2010. Variation rate of land use change in 2000-2005 was faster, as 2.4-6.3 times as that in 2005-2010. The total ecosystem services value mostly consisted of that of water body, grassland and forest, accounting for 93% approximately. During the study, the values of all kinds of the ecosystem services increased except for grassland and water body, the total ecosystem services value increased firstly and then decreased, and overall emerged as a reducing trend with the rate of 1.2%. In the process of the development of the west regions, it is necessary to pay more attention to the protection of natural resources and ecosystem restoration, so as to achieve sustainable development of resources, environment and social economy in the western regions.

[Evaluation of ecosystem provisioning service and its economic value].

Aiming at the fact that the current approaches of evaluating the efficacy of ecosystem provisioning service were lack of spatial information and did not take the accessibility of products into account, this paper established an evaluation model to simulate the spatial distribution of ecosystem provisioning service and its economic value, based on ArcGIS 9. 2 and taking the supply and demand factors of ecosystem products into account. The provision of timber product in Laojunshan in 2000 was analyzed with the model. In 2000, the total physical quantity of the timber' s provisioning service in Laojunshan was 11.12 x 10(4) m3 x a(-1), occupying 3.2% of the total increment of timber stock volume. The total provisioning service value of timber was 6669.27 x 10(4) yuan, among which, coniferous forest contributed most (90.41%). Due to the denser distribution of populations and roads in the eastern area of Laojunshan, some parts of the area being located outside of conservancy district, and forests being in scattered distribution, the spatial distribution pattern of the physical quantity of timber's provisioning service was higher in the eastern than in the western area.

[Ecosystem service valuation of Ertan Reservoir watershed in mitigating reservoir sand sedimentation].

By using software ArcGIS 9.2, an evaluation model was established to simulate the ecosystem service of Ertan Reservoir watershed in mitigating the sand sedimentation in the reservoir. In the meantime, sediment delivery ratio and universal soil loss equation were used to simulate the spatial patterns of the annual sediment yield and sediment retention in the watershed as well as the value during the service life period. In 2000, the total quantity of soil retention in the watershed was 12. 1 x 10(8) t x a(-1). The region with higher soil retention was near the main and branch streams of Yalong River, and that with higher sediment delivery ratio was near the streams and the Ertan Reservoir. The region with higher sediment yield and sediment retention was around the reservoir. The actual sediment yield in the study area was 629.3 x 10(4) t x a(-1), occupying 12.7% of the actual soil erosion volume. Farmland was the most important source of sediment yield, with its sediment yield occupying 62.9% of the total. The contribution of forestland to the mitigation of reservoir sand sedimentation was higher than that of the other lands on a per unit area basis. For the reservoir's designed operating life (100 a), the total value of the watershed in the service of mitigating Ertan Reservoir sand sedimentation was 2.75 billion yuan.

[A services value of different landscape types in Longitudinal Range-Gorge Region].

Based on the RS image of Longitudinal Range-Gorge Region (LRGR) in 2001, the study area was classified into seven first-class landscape types (forestland, grassland, farmland, wetland, water body, urban land, and glacier), and 26 second-class landscape types in consideration of climate belt, vegetation, and topography. By using GIS technology, the services value of different landscape types of LRGR were studied in regards to the study results on services value of Chinese terrestrial ecosystems. The results indicated that the total services value of LRGR was 5 302.35 x 10(8) yuan x a(-1), accounting for 9.47% of the whole country. The service value of soil conservation was the highest, which occupied 18.05% of the total services value, while the service values of gas adjustability and biodiversity protection ranked the second and third. Due to its distribution extent and services intensity per unit area, the forest landscape, which covered 66.11% of the total area, contributed most (85.34%) to the total service value of LRGR, followed by grassland and farmland landscapes.

[Effects of climate and land use change on the changes of vegetation coverage in farming-pastoral ecotone of Northern China].

Based on the remote sensing images and the meteorological data in 1986 and 2000, and by using the model of extracting vegetation coverage, the spatiotemporal changes of vegetation coverage in the farming-pastoral ecotone of Northern China in 1986-2000 were studied, with the effects of climate and land use change on the changes analyzed. The results showed that in this ecotone, the area with lower vegetation coverage was increasing, while that with higher vegetation coverage was in adverse. The regions with increasing vegetation coverage were mainly in the east of northeast section, the west of north section, and the west of northwest section of the ecotone, while the vegetation coverage in the other sections was obviously degraded. The vegetation coverage were positively correlated with precipitation and aridity index, but negatively correlated with temperature. The change direction and extent of the vegetation coverage varied with land use types.

[Effects of organic manure on the profile distribution of soil nitrate-N in a peach orchard].

In 2004 and 2005, a field experiment was conducted in a peach orchard in Pinggu District of Beijing to study the effects of organic manure on the profile distribution of nitrate-N in soil. Four treatments were installed, i.e., applying 6.75 x 10(4) kg x hm(-2) of organic manure both in 2004 and in 2005 (T1), no fertilization in 2004 but applying 13.5 x 10(4) kg x hm(-2) of organic manure in 2005 (T2), no fertilization in 2004 but applying 6.75 x 10(4) kg x hm(-2) of organic manure in 2005 (CK), and no fertilization both in 2004 and in 2005 (CK). In 2006, soil samples at the depth of 0-120 cm were collected from the treatments and analyzed. The results showed that soil nitrate-N had a relatively uniform distribution in the profile in CK, accumulated more at the depth of 0-60 cm and decreased gradually at 60-120 cm in T1 and T3, and increased with increasing depth, with the peak at the depth of 100-120 cm in T2. The soil nitrate-N content below 60 cm in T2 was the highest among all the treatments, indicating that applying excessive amount of organic manure could induce nitrate-N leaching. The profile distribution of soil nitrate-N had significant correlations with the total amount of applied organic manure, the amount of organic manure applied in the nearest year, and the distance of sampling sites from peach tree. A correlation model of organic manure treatments and soil nitrate-N distribution was established.

[Responses of soil fauna to environment degeneration in the process of wind erosion desertification of Hulunbeir steppe].

To reveal the relationships between soil fauna and soil environmental factors in the process of steppe desertification, field survey combined with laboratory analysis was made to study the community structure, population density and biodiversity of soil fauna, and their relationships with the changes of soil organic matter, hydrolysable nitrogen, available phosphorus and moisture contents and soil pH at different stages of desertification of Hulunbeir steppe. The soil faunal specimens collected belonged to 4 phyla, 6 classes and 12 orders. Nematoda was the only dominant group of medium- and small-sized soil fauna, occupying 94.3% of the total, while Coleoptera and Hemiptera were the dominant groups of large-sized soil fauna, with the amount of 79.7%. The group amount, population density, diversity, and evenness of soil fauna had an obvious decreasing trend with the aggravation of steppe desertification. At serious stage of desertification, soil fauna vanished completely. The population density of soil fauna in 0-20 cm soil layer had significant linear correlations with soil nutrients and moisture contents, soil pH, and litter mass, indicating that soil fauna had stronger sensibility to the changes of soil environmental factors in the process of wind erosion desertification of Hulunbeir steppe.

[Distribution features of nutrient and phytoplankton in incipient Three Gorges reservoir].

The distribution features of nutrient and chlorophyll a were determined by cruise during 2003-09-08 approximately 2003-09-15 with 11 sites in the Three Gorges reservoir. The results showed that the concentration of nitrogen was exceed the national surface water body quality standard III. The concentration of nitrogen range 1.01 approximately 1.35 mg x L(-1); Total phosphorus range 0.028 approximately 0.054 mg x L(-1); Kalium range 2.80 approximately 3.44 mg x L(-1); Total organic carbon range 1.92 approximately 2.59 mg x L(-1); Chlorophyll a range 1.58 approximately 7.53 mg x m(-3). The average concentration of chlorophyll a was 4.69 mg x m(-3) at surface layer. The correlation of nutrient and chlorophyll a were researched. It indicated there was a significant positive correlation (r = 0.7287) between chlorophyll a and NO3(-)-N. There was a significant negative correlation (r = -0.9207) between chlorophyll a and turbidity. Using the method of system cluster, it showed there was distinct distribution features which can be divided into three clusters. The upper river areas cluster included Changshou, Fuling,Fengdu, Zhongxian; The middle river areas cluster included Wanzhou, Yunyang and Fengjie; The down river areas included Wushan. The rate of diatom in phytoplankton was about 86%. Diatom was absolute predominance on 4 monitoring sites. The average of diatom was 129844 cells x L(-1). Amount of phytoplankton was increased along the river flow direction.