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Based on the meteorology dataset of 34 stations over the Yinshan area through the recent 30 years (1982-2010), we investigated the key environmental variables influencing potato yield using the correlation and regression methods. Two environmental variables, including the mean temperature difference, precipitation during the growing season, were selected as the major indexes for determining the suitable area for planting potato. Using the GIS-based small grid calculation model, we interpolated these two major environmental variables and produced the climatic map for potato in Yinshan area. The results showed the high potato yield area located in Qianshan and southern Houshan, and the medium-yield division was mainly concentrated in the central Houshan and north-west Qianshan, the low-yield division was distributed mainly in northern Yinshan. Moreover, this study examined the spatial patterns of potato production, and evaluated the stability of potato yield by combining the relative variability of potato yield. This study could provide valuable references for planting potato in Yinshan area.

By using water drop penetration time (WDPT) and molarity of ethanol droplet (MED) methods, the soil water repellence of undisturbed biological soil crusts (biocrusts) in five successional stages, from the hilly Loess Plateau region of China was tested. The five stages of biocrusts were light cyanobacterial crust, dark cyanobacterial crust, cyanobacterial with sparse moss crust, moss and tiny cyanobacteria patches crust and moss dominated crust. The results showed that 1) the soil water repellence was markedly increased both in the intensity and persistence since the formation of biocrusts. 2) The soil water repellence showed a decrease trend along with the successional stages of biocrusts. The soil water repellence of the biocrusts with the moss coverage above 20% was significantly lower than that of the cyanobacterial crusts. 3) The soil water repellence of the biocrusts was closely related to soil moisture and the dominant organism. The soil water repellence increased with the decrease of soil water content for the moss dominated biocrusts, while changed in a bimodal curve with the decrease of soil water content for the cyanobacterial biocrusts.

Soil surface roughness exerts profound influence on runoff and sediments yield from slopes. Biological soil crusts (BSCs) are ubiquitous living cover in the open spaces between plants in arid and semiarid ecosystems, which considerably impact the surface roughness. Aimed to determine the effect of biological crusts on the surface roughness and its influence factors, this study investigated the surface roughness of soil with BSCs at their different successional stages by using the chain method. Besides, the impacts of slope aspects, soil water content and freezing and thawing on surface roughness were also investigated. Then, the correlations between roughness and soil chemical and physical properties were evaluated. The results showed that soil surface roughness decreased at the initial successional stage of BSCs but increased along with BSCs' development in the region. Soil roughness tended to be stabile since BSCs developed ten years later. The roughness was reduced by 47.0% by the light cyanobacteria-dominated crust and 20.4% by the dark cyanobacteria-dominated crust (moss coverage < 20%), compared with the bare soil. Soil moisture significantly impacted surface roughness. The surface roughness of BSCs changed obviously with soil moisture in the early development, but only slightly in their later succession. Freezing-thawing also affected surface roughness with BSCs. Roughness was more susceptible to freezing-thawing in the early de- velopment of BSCs, with an increase of 29.7% compared with the bare soil. The surface roughness of late successional BSCs exhibited a slight change only after repeated freezing-thawing. The surface roughness of BSCs showed a statistically significant relationship with the coverage of moss (P < 0.1).

In 2012, a field experiment with different fertilizer treatments was conducted in the Stipa breviflora desert steppe of Inner Mongolia. The LI-8100 was used to investigate daily and seasonal variations of soil respiration rate, and the relationships between soil respiration rate and environmental factors were analyzed. The results showed that: 1) In the rapidly growing stage (August), the respiration rate in 10 g N x m(-2) was significantly higher than in the other treatments. No significant differences were observed among 5 g N x m(-2), 2.5 g N x m(-2) and CK. 2) During the early and middle growing stage (May to September), P fertilizer improved the soil respiration rate. 3) Fertilization did not change the daily and seasonal variations of soil respiration. The daily variations of soil respiration of all fertilization treatments were almost the same, with the highest values occurring within 10:00-14:00 and the lowest values occurring within 03:00-05:00. The peak of seasonal variation occurred in August. 4) The soil respiration rate was significantly related to soil temperature at 5 cm depth and soil moisture at 0-10 cm depth, and the determined coefficients were 0.40-0.58 and 0.51-0.70, respectively, indicating that soil moisture was the major factor affecting soil respiration.

Sustainability is the theme of our time and also the grandest challenge to humanity. Since the 1970s, the term, sustainable development, has frequently appeared in the scientific literature, governmental documents, media promotions for public goods, and commercial advertisements. However, the science that provides the theoretical foundation and practical guidance for sustainable development--sustainability science--only began to emerge in the beginning of the 21st century. Nevertheless, the field has rapidly developed in depth and expanded in scope during the past decade, with its core concepts and research methods coalescing. China, as the most populous country in the world and home to the philosophical root of sustainability science-the unity of man and nature, is obligated to take upon the challenge of our time, to facilitate global sustainability while pursuing the Chinese Dream, and to play a leading role in the development of sustainability science. Toward this grandiose goal, this paper presents the first Chinese introduction to sustainability science, which discusses its basic concepts, research questions, and future directions. Sustainability science is the study of the dynamic relationship between humans and the environment, particularly focusing on the vulnerability, robustness, resilience, and stability of the coupled human-environment system. It is a transdisciplinary science that integrates natural sciences with humanities and social sciences. It hinges on the environment-economy-society nexus, and merges basic and applied research. The key components of sustainability often change with time, place, and culture, and thus sustainability science needs to emphasize multi-scale studies in space and time, with emphasis on landscapes and regions over a horizon of 50 to 100 years. It needs to focus on the relationship between ecosystem services and human well-being, as influenced by biodiversity and ecosystem processes as well as climate change, land use change, and other socioeconomic drivers. Landscape sustainability is at the core of sustainability science, and is expected to be a hot research topic in the next few decades.

In this paper, the spatial pattern of Cleistogenes squarrosa population in different restorative succession communities of the typical steppe dominated by Stipa grandis and Leymus chinensis in Inner Mongolia was measured by photography orientation, and analyzed by complete spatial randomness model, Poisson cluster process, and nested double-cluster process. In severely degraded community, C. squarrosa population fitted well nested double-cluster process for all scales, i. e., high density small clusters existed at the centers of large clusters; whereas in 5-, 8-, and 21-year-old restored communities, C. squarrosa population fitted well Poisson cluster process for all scales, i. e. , high density small clusters did not exist at the centers of the clusters. It was suggested that facilitation was the dominant interaction in severely degraded community, while competition dominated in restored communities. The differences in the spatial pattern of C. squarrosa population during the restorative succession could be induced by the shift from facilitation to competition along the gradient of grazing stress.

To accurately interpolate the missing precipitation data from meteorological observation stations within a region to obtain a complete precipitation series is of significance in improving the spatial and temporal resolution in analyzing the effects of climate change. By using spatial correlation and stepwise regression techniques, this paper interpolated the missing precipitation data for an individual day or less than 7 days in a month from the 853 meteorological stations in the forest region of Eastern China in 1961-2010, as a consequent establishment of the complete time series precipitation datasets of the observation stations in 1961-2010 established. Based on these, trend analysis approach was applied to analyze the variation characteristics of the annual precipitation, annual precipitation days, and extreme precipitation events in the region in 1961-2010. During the study period, the annual precipitation in the region presented an insignificant increasing trend, with a tendency of 5.58 mm (10 a) -1, but the decadal variation was obvious. The annual precipitation days reduced significantly, while the annual extreme precipitation days and extreme precipitation volumes increased significantly, with a tendency of 0.12 d (10 a) -1 and 10. 22 mm (10 a)-1, respectively. Since the 1990s, the extreme precipitation events became frequently and intensively, and the proportion of the volumes of extreme precipitation to total precipitation increased significantly. Both the extreme precipitation days and the volumes of extreme precipitation had an abrupt change in 1993.

In order to investigate the effects of climate change on the rice production and rice planting pattern in Fujian Province, an analysis was made on the spatiotemporal distribution of air temperature and precipitation in rice growth period in the Province, and the possible changes of the local rice planting pattern in the future, based on the A2, B2, and A1 B scenarios of IPCC Special Report on Emission Scenario (SRES). In the future, the rice growth period's air temperature in the Province tended to be increased, and the increment would be increased with time, with the maximum for single cropping rice and being 0.3-2.4 degrees C and 1.5-3.4 degrees C in 2011-2030 and 2031 -2050, respectively. For early rice and late rice, the increment of their growth period's air temperature would be 0.2-0.9 degrees C and 0.7-1.7 degrees C in 2011-2030 and 0.3-2.1 degrees C and 0.5-3.6 degrees C in 2031-2050, respectively, but the annual fluctuation of the mean daily temperature would be most obvious for late rice. The rice growth period's precipitation in most parts of the Province also tended to be increased, and the increment for early rice, single cropping rice, and late rice would be 10%-40%, 10%-30%, and 10%-20%, respectively. The annual fluctuation of the precipitation would be most obvious for the early rice in southeastern Fujian. The elevated air temperature in the future could induce the increase of > or = 10 degrees C accumulated temperature, and lengthen the rice growth season, making it possible to replace early and medium-maturity varieties with late-maturity varieties, and to adopt double-rice planting pattern instead of single-rice planting pattern.

This paper studied the effects of 1-, 2- and 3 years of planting Pennisetum sp. on the plant- and insect diversity in the Pennisetum sp. communities, taking the barren mountain land without planting Pennisetum sp. as the control (CK). Compared with CK, the plant species richness in Pennisetum sp. communities with different years of planting was lower, but the coverage was higher. The coverage in the Pennisetum sp. community having been planted for 3 years was the highest, up to 91.6%, and 75.8% higher than the CK. The insect species richness in the Pennisetum sp. communities having been planted for 1, 2 and 3 years was 3.6, 5.3 and 5.6 times of the CK, respectively. The plant- and insect diversity indices, including Simpson index, Shannon index, evenness, Brillouin index, and McIntosh index for the Pennisetum sp. communities with different years of planting were significantly higher than the CK, which indicated that the growth of Pennisetum sp. could affect the plant- and insect diversity. With the increasing year of planting, the plant- and insect diversity in Pennisetum sp. communities tended to be stable.