Soil salinity evolution and its relationship with dynamics of groundwater in the oasis of inland river basins: case study from the Fubei region of Xinjiang Province, China.

Soil salinization is an important worldwide environmental problem, especially in arid and semi-arid regions. Knowledge of its temporal and spatial variability is crucial for the management of oasis agriculture. The study area has experienced dramatic change in the shallow groundwater table and soil salinization during the 20th century, especially in the past two decades. Classical statistics, geostatistics and geographic information system (GIS) were applied to estimate the spatial variability of the soil salt content in relation to the shallow groundwater table and land use from 1983 to 2005. Consumption of reservoir water for agricultural irrigation was the main cause of a rise in the shallow groundwater table under intense evapotranspiration conditions, and this led indirectly to soil salinization. The area of soil salt accumulation was greater in irrigated than in non-irrigated landscape types with an increasing of 40.04% from 1983 to 2005 in cropland at approximately 0.43 t ha(-1) year(-1), and an increase at approximately 0.68 t ha(-1) year(-1) in saline alkaline land. Maps of the shallow groundwater table in 1985 and 2000 were used to deduce maps for 1983 and 1999, respectively, and the registration accuracy was 99%.

[Comparison of sustainable development status in Heilongjiang Province based on traditional ecological footprint method and emergy ecological footprint method].

By using traditional ecological footprint method and its modification, emergy ecological footprint method, the sustainable development status of Heilongjiang Province in 2005 was analyzed. The results showed that the ecological deficits of Heilongjiang Province in 2005 based on emergy and conventional ecological footprint methods were 1.919 and 0.6256 hm2 x cap(-1), respectively. The ecological footprint value based on the two methods both exceeded its carrying capacity, which indicated that the social and economic development of the study area was not sustainable. Emergy ecological footprint method was used to discuss the relationships between human's material demand and ecosystem resources supply, and more stable parameters such as emergy transformity and emergy density were introduced into emergy ecological footprint method, which overcame some of the shortcomings of conventional ecological method.

[Temporal and spatial variation of land degradation in alluvial oasis at northern slope of Tianshan Mountain].

Taking the Fubei Farm, a farming oasis of Sangong River watershed at the northern slope of Tianshan Mountain as study area, and by the methods of geostatistics, GIS and RS, this paper studied the temporal and spatial variation of land degradation in topsoil (0-20 cm) and its relationship with landscape structure. The results showed that in this oasis, human activity was the key factor resulting in the increase of landscape fragmentation and diversity. From 1983 to 2005, the land degradation area decreased by 26.69%, and the degradation degree was higher in the regions adjacent to desert than in those further inside the oasis. Gray desert soil was degraded much more seriously than saline soil and aquic soil. The regions of poor land quality had an alleviated degradation, with 65.38% of land area improved, while those of good land quality had an aggravated degradation, with 33.38% of land area degraded.

[Urban landscape functional regionalization and development strategy in Shenyang City].

According to the topography, land type suitability and human activity, the urban area of Shenyang City was regionalized into four landscape functional regions, i.e., economic and cultural supporting region, ecological equilibrium region (including northern high plain equilibrium sub-region and southern low plain equilibrium sub-region), ecological supporting region (including eastern ecological supporting sub-region and western ecological supporting sub-region), and ecological barrier region. In economic and cultural supporting region, the radiation of function in economy and culture should be strengthened, and the natural and artificial green space system should be preserved. In ecological supporting region, environmentally friendly industries should be developed to provide diverse ecological service well. As a combination of natural and man-made ecological system, the ecological equilibrium region could balance and steady the other regional services. To keep the balance between artificial and natural landscapes in this region, it was needed to control the expansion of construction land, maintain the natural and semi-natural system, and build the ecological corridors to connect various natural system. In ecological barrier region, the ecological environment was in instability, where the protection and production should be dealt with equally.

[Landscape pattern and its functioning after ecological reconstruction in black soil of northern China].

Taken Baiquan County in Heilongjiang Province as a case, this paper studied the effects of regional ecological reconstruction on agricultural landscape pattern and its functioning in soil and water conservation, with the spatial expression and quantity identification investigated based on Geographic Information System (GIS) and field data. The landscape pattern index in class scale, transition matrix of landscape elements, macrostructure of shelter-belt networks, and spatial distribution and hydrological characteristic of reservoirs and ponds in 1989 and 2002, as well as the effects of landscape pattern and its spatial configuration change on soil and water loss were compared. The results showed that artificial ecological reconstruction changed the quantity and spatial configuration of landscape patterns in regional scale, and exerted a significant effect on soil and water conservation. From 1989 to 2002, farmland area reduced 24 731.01 hm2, while forest land, grassland and water area increased 11 728.56, 1838.97 and 1190.97 hm2, respectively. The controlled eroded land increased by 55%, and the shelterbelt-protected farmland increased by 82.2%. The number and storage capacity of reservoirs and ponds added up to 1 490 and 2.4 x 10(8) m3, respectively, and 43.7% of intercepted surface runoff of whole landscape was collected.

[Forest landscape restoration and its affecting factors in burned area of northern Great Xing'an Mountains--taking forest coverage as an example].

Forest landscape restoration has been an attractive issue since the catastrophic fire took place on the northern slope of Great Xing'an Mountains in 1987. Based on the China forest inventory data and employing Kendall Bivariate and Distances Correlation Analyses, an investigation was made to search for what changes of the forest coverage pattern being happened in this area during the past 13 years after fire, and how the fire severity, foster type and terrain factors influenced the restoration of forest coverage. The results showed that the forest coverage in 2000 changed a lot, in comparing with that in 1987 before fire. The percentage of non-stocked land area and coverage grade declined markedly, with lower coverage grade increased. Among all test factors, fire severity which was inversely correlated with forest coverage grade was the key one. Though the regeneration measures didn't markedly affect forest coverage restoration within a short period, they might shorten the cycle of forest succession and promote the productivity of coniferous forest in the future. Among three terrain factors, slope was the strongest one affecting forest coverage, followed by position and aspect.

[Landscape health assessment on Ejin natural oasis].

Landscape scale ecosystem health research could not only provide a basis for integrating natural ecological processes and social economic values, but also provide an appreciated temporal and spatial scale in dealing with the issues of resources and environment. The Ejin natural oasis landscape is at the lower reach of Heihe river basin in the arid inland regions of northwestern China. Owing to the lack of sufficient water resource from the upper reaches of Heihe River, a series of ecological and environmental problems are getting more serious in the oasis in recent years. Based on the past decade landscape change of the Ejin natural oasis, this paper developed a landscape health indicators system including landscape change indicators, bio-physical indicators, eco-environmental indicators and social-economic indicators, and established the criteria and weightiness for assessment indicators. The landscape health index (LHI) was finally figured out as 0. 3042 by using fuzzy comprehensive evaluation method, which showed that the health condition of Ejin natural oasis landscape was ranked to "severely ill level" in the landscape health assessment criteria system. The landscape health of Ejin natural oasis landscape today is much worse than in the past years, with a badly unsustainable developing trend.

Methane (CH4) emission from a natural wetland of northern China.

This article focuses on the seasonal and spatial changes of CH4 emission from the natural reed marsh of Liaohe Delta, China. Field experiments showed that this natural wetland acts as a CH4 sink in spring (-30 approximately -1000 microg/m2 x h), a strong source in summer (400-3000 microg/m2 x h) and a weak source in autumn (< 400 microg/m2 x h). Reed plants play an important role in transportation and emission of methane produced in soil. According to our field measurement data, CH4 emission is positively related to temperature, and negatively related to Eh value and water depth. The activity of methanogenic bacteria is higher in the rhizosphere and surface layer, and thus contributes more in CH4 emission than other layers.

[Structural characteristics and heterogeneity analysis of yard-greenbelts in Shenyang city].

The analysis of the landscape and pattern of yard-greenbelts in Shenyang city indicated that residential greenbelt had the highest green path number, occupying 32.2% of all greenbelt types, but the virescence situation in residential area was the worst because its greenbelt ratio was only 19.5% in average. The average area of all yards was 4.04 hm2, with an average greenbelt of 0.93 hm2, and the green belt ratio was 23% in average that was lower than the standard established by the government. About 62.7% of all yards were lower than 15% in virescence, and 30% of them had a < 13.3% of virescence. Micro-green patch was dominant (over 70%) in Shenyang yard-greenbelts. Landscape diversity index of residential areas was the highest, while that of hospital and army units was the lowest. The dominant degrees of all yard-greenbelt types in the researched 7 districts of the city were obviously different. The dominance of factory greenbelt in Yuhong district was 31.23 times of that in Heping district. The evenness indexes were also very different, the highest in residential greenbelt and the lowest in army unit. The highest fragmentation degree was in residential greenbelt and the lowest in army unit. The fragmentation degrees of old districts, especially in Shenhe district were more serious than the new districts.

[Regional ecological construction and mission of landscape ecology].

The eco-construction on regional and landscape scale is the one which can be used to specific landscape and intercrossing ecosystem in specific region including performing scientific administration of ecosystem and optimizing environmental function. Recently, the government has taken a series of significant projects into action, such as national forest protection item, partly forest restoration, and adjustment of water, etc. Enforcing regional eco-construction and maintaining the ecology security of the nation have become the strategic requisition. In various regions, different eco-construction should be applied, for example, performing ecological safeguard measure in ecological sensitive zone, accommodating the ecological load in ecological fragile zone, etc., which can control the activities of human being, so that, sustainable development can be reached. Facing opportunity and challenge in the development of landscape ecology, we have some key topics: landscape pattern of ecological security, land use and ecological process, landscape changes under human activity stress, quantitative evaluation of the influence on human being activities, evaluation of zonal ecological security and advance warning of ecological risk, and planning and optimizing of model in landscape eco-construction.

[Impact of groundwater resource temporal-spatial change in Minqin oasis on ecological security of irrigation region landscape].

By the GIS technology, this paper studied the impact of groundwater resource temporal-spatial change in the lake area of Minqin Oasis on the ecological security of irrigation region landscape. The results showed that the depth of groundwater was descending continuously, the velocity of groundwater line change in the center of irrigation region was faster than that in the edge region, and consequently, the area of the descending funnel of groundwater line was enlarged. From 1987 to 2001, the area with a groundwater depth deeper than 3 m was increased from 81.2% to 97.4%. The descending of groundwater line due to soil water reducing was the main reason that resulted in the destruction and deadness of forests. When the depth of groundwater was deeper than 8 m and soil water content was less than 12%, the die-back rate of tree was morn than 90%, and that of shrub was more than 50%. Impacted by the descend of groundwater depth, the area of forest land, shrub land and open-canopy land was decreased by 67%, 54% and 31%, and the number of their patches was decreased by 35, 42 and 50, respectively. The mineralization degree of groundwater in northern irrigation region increased obviously, and changed the safe pattern of crop growth. The benefit of agriculture decreased, and the adjustment of planting construction was restricted seriously, which became the main impact factor on the ecological security of irrigation region. Reasonably distributing water resource between upper and lower river basin, reducing unreasonable land use, decreasing farmland area, and constructing safety landscape pattern could lead to the balance between the exploitation and replenishment of groundwater resource, prevent the descend of groundwater depth and the increase of groundwater mineralization, and improve the ecological security of the irrigation region.

[Forest landscape change and its driving force during past ten years in Bilahe forest region, Inner Mongolia].

Based on RS and GIS, this paper studied the forest landscape change during the past ten years in Bilahe forest region, Inner Mongolia, from the aspects of general landscape features, individual patch characteristics, and relationship among patches. The results showed that the forest landscape changed a lot due to the stronger human intervention on forest ecosystem. The general tendency was that the human patches (residential area and cultivated land) were! expanding quickly, whereas the natural patches (forest patches, etc.) were shrinking gradually. The results of area transformation matrix showed that in 1997, 30.87% of cultivated lands were transformed from Quercus mongolica. According to the analysis of landscape heterogeneity, the patches were increased by 68.80%, but their average area was reduced by 4.82%. In 1988, the landscape dominated by few patches changed to a landscape with comparatively even distribution of patches, due to the decrease of landscape dominance and contagion, and the increase of landscape diversity. Based on the analyses of physical geography and social economics in the study area and the regions related, this paper discovered that the most decisive driving forces of landscape changes were fire intervention, deforestation, and reclamation of virgin land.

[Spatial neighboring characteristics among patch types in oasis and its ecological security].

In this paper, the spatial neighboring length and number between oasis types and desert or salina-marsh in the Jinta Oasis located in the arid Heihe River Basin of Northwest China were calculated by using ArcView3.0a and buffer zone analysis methods, and the threatening degree of oasis ecological security was discussed. The results indicated that it was different in neighboring length and number between oasis types and desert or salina-marsh, and the influencing area by desert and salina-marsh patches was also different. Grassland and farmland had more neighboring length and numbers with desert or salina-marsh patches, and impacted by desertification seriously. Forest and farmland had more length and numbers adjacent to salina-marsh, and influenced by salinization severely. The assessment of ecological security based on spatial analysis could reveal the threatening degree of oasis by desertification and salinization.

[Spatial pattern analysis of forest landscape in low coteau of middle Qilian Mountains].

Based on the vegetation map and the relief map, using GIS and Fragstats, the spatial pattern of forest landscape of Xishui reserve in Qilian Mountains were analyzed. The results showed that the distribution of the vegetation was impacted mostly by altitude and aspect, grasslant was mostly distributed on the land of altitude 2,500-2,900 m and aspect of south and southwest, Picea crassifolia forest was always in the land of altitude 2,900-3,300 m and aspect of north, northeast, east and northwest, and shrubbery was in the land of altitude 3,300-3,700 m. The grassland had the biggest area and its connectivity and integrality were the best. The biggest MPFD of Picea crassifolia forest meant that its shape was the most complicated, its mean patch area was small, and the distance between the patches was short. So Picea crassifolia forest was easy to be impacted by some disturbance. The forest suitable land and Sabina przewalskii forest showed more outstretched characteristics than farmland and land with few trees. The mean nearest-neighbor distance of the poplar forest was the biggest in all the landscape elements, so the poplar forest's fragmentized degree was the highest in all the landscape elements.

[Landscape changes of Minqin oasis in Gansu Province and its driving force].

Based on the technology of GIS, RS and using FRAGSTATS, studies on the landscape changes of Minqin oasis during 1987 to 2001 showed that the transitions of landscape patches were complex, and open up wasteland took place during 1994 to 1998 in the south of the oasis where the condition of water was better and desertization took place during 1998 to 2001 in the north of the oasis where the condition of water was worse. The decreasing of the Shannon's diversity index and the Shannon's evenness index and the increasing of Contagion index showed that human beings reconstructing the landscape of the oasis began stronger than before. Unreasonable land use was changed the landscape pattern, and the condition of water resource accelerated the landscape change.

[A review on road ecology].

Roads are a widespread and increasing feature of most landscapes, and have great ecological effects, e.g., increased mortality of animals and plants and habitat loss from road construction, alteration of the physical and chemical environment, and changes in roadsides vegetation. The great impact on animal population includes road-kills, limiting population, road avoidance causing home arrange shift, modification of movement pattern and barrier effect subdividing habitat and populations. Roads alter landscape spatial pattern and interrupt horizontal ecological flows strongly. These impacts can be assayed by indices of road density, road-effect zone and road location. Furthermore, important applications of road ecology to planning, conservation and management are essential and potential. Road ecology presents us a surprising frontier of ecology.

Hydrological adjustment and flooding control of wetlands in the Liaohe Delta.

The function of estuary wetland on hydrological adjustment and flooding control is studied in this paper. It is estimated that the evapotranspiration in the reed field during growth season (June to October) is 722.9 mm, which is 37.5% higher than large water body (E601: 525.9 mm). The water replacement rate in the reed field can reach 95% only when the rains continuously for 11 days and the precipitation reached 912 mm. For the water balance in the paddy field, the total water requirement ranges between 1920 and 1860 mm, among which, 31% is from precipitation, and the left is provided by reservoirs. The water usage efficiency is 0.35 at present productivity. Based on the landscape characteristics and functionalities on flooding control, 5 functional zones are designed for the Liaohe Delta; key protected area; underground storage area; flooding discharge area; flood diversion area in emergency; and flood control drainage area.

[On the basic concepts and contents of ecological security].

Security is the inverse function of risk, generally regarded as safeguard degree expectation state of assessment object or reliability of prevent imperfect and uncertainty event to happen. Ecological security can defined as mankind's ensure degree un-effected by ecological destroy and environmental pollution in yield, living and health, including basic element of water and food security, air quality and green environment. The mostly content of ecological security consists of ecological health diagnosis, regional ecological risk analysis, landscape security pattern, ecological security monitoring and prediction, and ecological security management and guarantee etc. Study on regional ecological security has characteristics of macro-scope and pertinence, assessment criterion of relativity and expansibility. Ecological security prediction and design should embody the capability of human activity. At last, authors discuss the measures of the ecological security ensure of inland watershed and ecological security analysis of oasis landscape.

[Classification, application, and creation of landscape indices].

In landscape ecology, it is very important to understand and grasp the ecological principles of landscape transformation. One of the research methods in common use is to describe landscape pattern and its transformation, and then connect landscape pattern with process by means of landscape indices. Based on the previous studies on landscape indices, some researches on the landscape indices' classification, descriptive ability, relationship among indices and indices' creation were conducted in this paper. Moreover, the general principles of applying landscape indices from two different levels, namely, from single index level and from index system level, were put forward.