The spatiotemporal landscape heterogeneity implies multiple biodiversity mechanisms across scales, and the cross-disciplinary studies between landscape ecology and biodiversity are becoming a new research field in China. This paper briefly reviews the development of the field by comparing papers published in international journals and Chinese journals; then it investigates the differences in the trends and focuses between international and Chinese studies. We also introduce several study areas that have emerged over the last 10 years in this field, including metacommunity assembly, landscape genetics, biodiversity and ecosystem service relationship, and landscape planning for biodiversity conservation. The major advances emerging in this field in China over the past 5 years can be classified into six subject areas: 1) effects of urban landscape and urbanization on biodiversity; 2) altitudinal patterns of biodiversity in mountain landscapes; 3) effects of topographic heterogeneity on plant community assembly and species coexistence; 4) impacts of landscape patterns and processes on animal behaviors; 5) forest fires and spatiotemporal patterns of vegetation responses; and 6) landscape ecology applications in natural conservation planning and design. In an attempt to promote cross-field studies between geography and ecology, this special issue collected 10 research articles, involving multiple landscape types and biological assemblages, in order to explore the interaction between landscape features and biodiversity. We anticipate that the future development of this active front will be primarily driven by the application of novel information techniques and the realistic demands of sustainability issues, in addition to answering scientific questions cross scales.
Poverty is a key issue restricting rural sustainable development; concurrently, regional land degradation impedes agricultural development and rural revitalization. China faces severe land degradation and deepening rural poverty under the context of rapid urbanization. To address these challenges, sustainable land use is an important tool in our society’s economic development. Rural engineering, including rural land consolidation, reclamation, restoration, reallocation, improvement, and development, is the most direct and effective way to achieve rural sustainable poverty alleviation. This study clarifies the framework between land engineering and rural poverty alleviation, and introduces land engineering technologies, newly created land utilization practices, and the contributions to poverty alleviation in representative degraded land regions. Land engineering can increase land quantity, improve land quality, enhance land ecological function, and promote man-land system coupling. Further, it can erase rural poverty by increasing county revenue and households’ income, lead to industrial development, and improve living environment. Specifically, degraded sandy land, gully land, hollowed construction land, and barren hilly land are transformed into productive land by improving the land structure. Innovated land engineering technologies and sustainable land utilization modes can provide the basic theories and reference approaches for rural poverty alleviation. Identifying obstacles to effective land and corresponding engineering practices are crucial to regional land exploitation and development, improving quality of life and alleviating rural poverty.
Exploring the impact of land consolidation on the changes of local land use and the landscape patterns is important for optimizing land consolidation models and thus accelerating the sustainable development of local communities. Using a typical small watershed in Yan’an City (Shaanxi, China), the impact of gully land consolidation on land use and landscape pattern change, based on high-resolution remote sensing image data and landscape pattern analysis, was investigated. The results showed that: (1) The terraces, sloping fields, shrub land and grassland at the bottom and both sides of the gully were converted mainly to high quality check dam land. Also, some of the shrub land, due to biological measures, was converted to more ecologically suitable native forest. Thus, the areas of check dam land and forests increased by 159 and 70 ha, while that of shrub land, grassland and sloping fields decreased by 112, 63 and 59 ha, respectively. (2) The average patch area and patch cohesion index for the check dam land increased, which indicated that the production function improved. The landscape shape index and the patch cohesion index for forestland and shrub land were maintained at a high level, and thus the ecological function remained stable. (3) At the watershed level, the degree of fragmentation of the landscape decreased and the landscape became more diversified and balanced; the anti-jamming capability of the landscape and the stability of the ecosystem improved also. Research suggests that implementing gully land consolidation in a rational manner may contribute to improvements in the structure of local land use and the patterns of landscape.
The mountainous and hilly region plays an important role in ecological safety and production in China. However, recent studies have poorly characterized the parallel structure of land use in the valleys of the mountainous and hilly region using topographic factors (e.g. elevation, slope, aspect). Here, the loess hilly region of northern Shaanxi Province is used as a representative case area to analyze the vertical distribution pattern of land-use conversion using the relative elevation concept and the HAND index. The differences in the vertical structure of land-use conversion between absolute elevation and relative elevation were compared. We found that the classifications of absolute and relative elevation had similar proportions of each relative elevation grade in each absolute elevation grade. Cropland, woodland, and grassland were distributed evenly in each grade of absolute/relative elevation, while water body, built-up land and unused land were more likely to spread in low grades of relative elevation than those of absolute elevation. The land-use conversion (i.e. loss of cropland and gain in woodland and built-up land) showed an apparently stepped distribution with relative elevation classification, suitable for revealing vertical distributions of land-use conversion in the loess hilly region. Cropland transformed to woodland was mainly distributed in high grade of relative elevation, decreasing with a decrease in grades, while built-up land transformed from cropland and grassland was mainly distributed in low grade of relative elevation, decreasing with increases in grades. The grade of relative elevation where cropland transformed to woodland descended with the implementation of the Grain for Green Project. Our results suggest that it is better to analyze the vertical distribution of land-use conversion with relative elevation classification in hilly regions.
Building the Belt and Road is initiatives of China to promote win-win international cooperation in the new era, aiming at green, health, intellect and peace and the joint development with people of the countries along the route. Systematic analysis on environmental characteristics, evolutionary tendency and future risks are certainly the scientific fundamentals of sustainable development for the Belt and Road construction. Applied remote sensing monitoring, statistical analysis, this paper investigates the regional characteristics of climate, topography, soil, hydrology, vegetation cover and terrestrial ecosystems production, as well as socio-economic conditions. Based on the regional characteristics, the Belt and Road is divided into 9 sub-regions: Central and Eastern Europe sub-region with cold and humid climate, Mongolia and Russia sub-region with cold and arid climate, Central and West Asia arid sub-region, Southeast Asia sub-region with warm and humid climate, Pakistan arid sub-region, Bangladesh-India-Myanmar sub-region with warm and humid climate, Eastern China monsoon sub-region, Northwest China arid sub-region and Tibetan Plateau sub-region. Combining modeling simulation with scenario projections, natural disaster assessment methodology is used to assess the risk of extreme events including heat waves, droughts and floods in the coming 30 years (2021-2050). Results show that, on the basis of the regional framework, the western Eurasia would be a warming trend; both sides of Qinghai-Tibet Plateau in high temperature and heat waves risk; Central and Eastern Europe sub-region with cold and humid climate in high drought risk; Bangladesh-India-Myanmar sub-region with warm and humid climate as well as Eastern China in high risk of flooding.
Investigating and monitoring the area of cultivated land reclaimed from rural settlements is important to optimize rural land use and understand spatial patterns. Measuring cultivated land area is costly and inefficient, however, as this land use type is often widely dispersed and scattered. A new method is therefore explored in this study that utilizes a Phantom2 Vision + (P2V), one kind of Dajiang (DJI) unmanned aerial vehicle (UAV). The method proposed here includes generating rural settlement images using a P2V UAV, subsequently correcting them using a camera lens model, matching them with geo-coded high resolution alternatives, mosaicking them, measuring the area of cultivated land reclaimed from rural settlements, evaluating measurement accuracy, and analyzing overall efficiency. The results of this study show that use of a P2V UAV is reasonable in price, less than 8000 yuan (RMB), and that this method is able to measure cultivated land area reclaimed from rural settlements with 99% accuracy. This method is therefore low cost, highly efficient, and low risk, as well as being easy to learn and use. This UAV-based approach is also likely to be easily popularized and be particularly useful both for application across plains and flats as well as over mountains and hills. The method proposed in this study is also likely to prove beneficial for monitoring and managing rural land use and future consolidation.
This paper echoes a tradition in agricultural geography by focusing on a single crop: cherries. It illustrates how developments associated with globalisation and growing urban markets are re-shaping rural areas. The interplay between global and local is investigated in two different contexts. A Chinese example reflects transformations affecting the countryside following national economic reforms. Focusing on the hinterland of Xi’an, capital of Shaanxi Province, it examines farmers’ responses to the changing socio-political context and the rising size and wealth of the local market. Individual initiatives backed by government support have spawned localised concentrations of cherry growing and increased horticultural production. Farm-based tourism is creating new relationships between farmers and consumers, with farms becoming more diversified and multifunctional. The second example is the Adelaide Hills, South Australia, where cherry growing is increasingly combined with direct sales to consumers and gastronomic tourism. The paper addresses contrasts and similarities between the two examples in the interplay between global and local, and a ‘multifunctional transition’ in farming. Concluding remarks include reference to new economic links forged between China and Australia through relaxations on cherry imports to China and new patterns of Chinese foreign direct investment into Australian cherry production. A research agenda for future research is suggested.
Lateral migration of the Bhagirathi River temporally creates unavoidable geomorphic hazards in West Bengal, India. The Bhagirathi River flows SW for ~67.30 km between the confluence point of Ajay and Jalangi rivers in East Burdwan and Nadia districts of West Bengal. The course of Bhagirathi is notably migration prone and cultivates problematic changes along its course over time. In the study, we have looked into its migration tendency and unpredictability for past 238 years and then predicted the lateral shifting of river centerline using temporal satellite imageries - Landsat-5 (TM) of 1987 (8, December), 1995 (28, January), 2005 (7, January) and LISS-IV satellite imagery (2017, 5 January);SOI Toposheet - 1968-1969 (79A/2, 79A/3, 79A/6 and 79A/7) and Rennell’s map of 1779. Other highlights are the quest of fluvial features, oxbow lakes, mid-channel bars, channel migration rate, meander geometry, channel sinuosity in different parts of river course and the parts that experience intensive bank erosion. The entire river course has been subdivided into three segments; viz. reaches A, B and C. Investigation displays that degree of sinuosity decreases from its anterior course (1968) to the existing course (2017). Reach-specific outputs display that reach B is highly sinuous (SI value 1.94 in 2017) and SI increases temporarily, whereas for reaches A and C it decreases with time. The rate of migration is higher in reach B than that in reaches C and A. The study displays a notably decreasing trend of migration in comparison with its previous lateral migration and shows that the migration nature over time is intensively inconsistent and unpredictable except very few portions of the river course. The nature of deposition within the river channel shows an unstable behavior during the entire period of the study. Meander geometry depicts a rapid change of river course innate to meander bends and shows a higher rate of migration by meander loop cut-off rather than lateral migration that reflects the inconsistency, erosion vulnerability and unpredictable nature of migration. The present work offers a valuable source to comprehend channel changes in Bhagirathi River and serve as an efficacious base for river-bank migration and erosion hazard planning and management.
The study of multi-dimensional expansion of urban space (MEUS) addresses the laws of urban spatial expansion from all directions and angles. Using Nanjing as an example, this paper constructs multi-temporal, urban three-dimensional models based on RS and GIS technology and then conducts qualitative and quantitative analysis of MEUS using plot ratio change maps and MEUS quantitative index for built-up areas. Based especially on the concept of volume growth contribution rate, this paper analyzes the characteristics of MEUS in different stages. The results show that in 2000-2004, planar expansion played the main role, the internal potential development (IPD) intensity of the urban built-up areas was relatively large, and the volume growth contribution rate was low; in 2004-2008, planar expansion accelerated, and IPD slowed down; in 2008-2012, planar expansion slowed while IPD intensity increased; the contribution rates of volume growth of urban IPD for the three periods were 22.21%, 24.51% and 73.38%, respectively. This study expands the research perspective of urban spatial expansion, and the adopted methods are instructive and meaningful for MEUS research. In addition, the results of this study will deepen the understanding of MEUS laws and help improve scientific decision-making for urban planning and urban land use management.
From 1992 to 2015, ecological environment has been threatened by the changes of cropland around the world. In order to evaluate the impact of cropland changes on ecosystem, we calculated the response of terrestrial ecosystem service values (TESVs) variation to cropland conversion based on land-use data from European Space Agency (ESA). The results showed that cropland changes were responsible for an absolute loss of $166.82 billion, equivalent to 1.17% of global TESVs in 1992. Among the different regions, the impact of cropland changes on TESVs was significant in South America and Africa but not obvious in Oceania, Asia and Europe. Cropland expansion from tropical forest was the main reason for decreases in TESVs globally, especially in South America, Africa and Asia. The effect of wetland converted to cropland was notable in North America and Europe while grassland converted to cropland played an important role in Oceania, Africa and Asia. In Europe, the force of urban expansion cannot be ignored as well. The conversion of cropland to tropical or temperate forest partly compensated for the loss of TESVs globally, especially in Asia.
Land use in the northeast region of Thailand has changed dramatically in the past two decades. These changes are mainly due to the government policies, which launched a scheme to promote rubber plantation during 2003-2013 targeting to solve the problem of poverty in the region. At least 50,000 ha of paddy fields were found to be converted to other land use types between 2002 and 2012. This study was conducted in Nong Khai and Bueng Kan province of northeast Thailand, where massive rubber plantation is going on prompting significant amount of land-use change, with the objective of investigating how land-use changes will affect on food availability in future. We analyzed land-use changes of the past and simulated future land uses using GIS and Landsat Thematic Mapper Data. The most obvious change was the decrease in paddy field and an increase in rubber plantation. This eventually leads to decreased paddy production affecting food supply of farm households. The land use projections for 2032 were done for three scenarios using Dyna-CLUE model. Unlike business as usual scenario, which will further decrease the paddy area, other scenarios with different land use policies if implemented will help protect paddy areas and thus achieving higher food production locally. The lack of implementation of proper spatial policies will lead to a further loss of paddy areas at macro level. The smallholder farmers may be highly vulnerable to land use-change and experience significant food crop losses, food insecurity and income loss when they change the land to rubber and there is market failure.
Understanding biogeographic patterns and the mechanisms underlying them has been a main issue in macroecology and biogeography, and has implications for biodiversity conservation and ecosystem sustainability. Evergreen broad-leaved woody plants (EBWPs) are important components of numerous biomes and are the main contributors to the flora south of 35°N in China. We calculated the grid cell values of species richness (SR) for a total of 6265 EBWP species in China, including its four growth-forms (i.e., tree, shrub, vine, and bamboo), and estimated their phylogenetic structure using the standardized phylogenetic diversity (SPD) and net relatedness index (NRI). Then we linked the three biogeographical patterns that were observed with each single environmental variable representing the current climate, the last glacial maximum (LGM)-present climate variability, and habitat heterogeneity, using ordinary least squares regression with a modified t-test to account for spatial autocorrelation. The partial regression method based on a general linear model was used to decompose the contributions of current and historical environmental factors to the biogeographical patterns observed. The results showed that most regions with high numbers of EBWP species and phylogenetic diversity were distributed in tropical and subtropical mountains with evergreen shrubs extending to Northeast China. Current mean annual precipitation was the best single predictor. Topographic variation and its effect on temperature variation was the best single predictor for SPD and NRI. Partial regression indicated that the current climate dominated the SR patterns of Chinese EBWPs. The effect of paleo-climate variation on SR patterns mostly overlapped with that of the current climate. In contrast, the phylogenetic structure represented by SPD and NRI was constrained by paleo-climate to much larger extents than diversity, which was reflected by the LGM-present climate variation and topography-derived habitat heterogeneity in China. Our study highlights the importance of embedding multiple dimensions of biodiversity into a temporally hierarchical framework for understanding the biogeographical patterns, and provides important baseline information for predicting shifts in plant diversity under climate change.
Species abundance and habitat distribution are two important aspects of species conservation studies and both are affected by similar environmental factors. Forest resource inventory data in 2010 were used to evaluate the patterns of habitat for target species of Cervidae in six typical forestry bureaus of the Yichun forest area in the Lesser Xing’an Mountains, northeastern China. A habitat suitability index (HSI) model was used based on elevation, slope, aspect, vegetation and age of tree. These five environmental factors were selected by boosted regression tree (BRT) analysis from 14 environmental variables collected during field surveys. Changes in habitat caused by anthropogenic activities mainly involving settlement and road factors were also considered. The results identified 1780.49 km2 of most-suitable and 1770.70 km2 of unsuitable habitat areas under natural conditions, covering 16.38% and 16.29% of the entire study area, respectively. The area of most-suitable habitat had been reduced by 4.86% when human interference was taken into account, whereas the unsuitable habitat area had increased by 11.3%, indicating that anthropogenic disturbance turned some potential habitats into unsuitable ones. Landscape metrics indicated that average patch area declined while patch density and edge density increased. This suggests that as habitat becomes fragmented and its quality becomes degraded by human activities, cervid populations will be threatened with extirpation. The study helped identify the spatial extent of habitat influenced by anthropogenic interference for the local cervid population. As cervid species clearly avoid human activities, more attention should be paid on considering the way and intensity of human activities for habitat management as fully as possible.
Land use/land cover change (LUCC) has considerable impact on ecosystem services. It is essential to quantify the spatiotemporal heterogeneity of ecosystem services from the perspective of LUCC, which will benefit regional land management and ecological protection. We analyzed land use change in the Pearl River Delta from 2000 to 2015, and we used a spatially explicit integrated modeling tool (InVEST) for quantification of ecosystem services-water yield, carbon storage, soil retention, and food supply. The results revealed increases in the areas of grassland and built-up land, and decreases in the areas of woodland, cropland, water body, and unused land during 2000 to 2015, which have caused increase in water yield and carbon storage, while decrease in soil retention and food supply. The dynamic changes of woodland, grassland, cropland, and built-up land were the main driving factors in the relationship of trade-offs and synergies among the four ecosystem services, which are ubiquitous. Those all illustrate the importance of considering ecosystem services in decision making related to land use and land management.
Based on the data of relative soil moisture in 653 agricultural meteorological stations during the period of 1993?2013 in China, the characteristics and regularity of spatial and temporal variation of relative soil moisture in China’s farmland were analyzed and discussed using geostatistical methods. The results showed that the relative soil moisture of China’s farmland has shown a fluctuant increasing trend since 1993. The relative soil moisture of China’s farmland is more than 60% in general, its distribution area has been expanded northward and westward with the summer monsoon since mid-April and began to shrink eastward and southward in late October. The value of relative soil moisture increases with the increase of soil depth. On an interannual scale, the relative soil moisture of farmland increased fastest in summer and autumn, and its variation range decreased with the increase of soil depth. The relative soil moisture was positively correlated with precipitation, and negatively correlated with potential evaporation and temperature. The correlation between relative soil moisture and various meteorological factors weakened as soil depth increased. The meteorological factors have a great influence on relative soil moisture of dry land in spring, summer and autumn and they also have a greater impact on relative soil moisture of paddy fields in winter.
Quantitative characterization of environmental characteristics of cropland (ECC) plays an important role in maintaining sustainable development of agricultural systems and ensuring regional food security. In this study, the changes in ECC over the Songnen Plain, a major grain crops production region in Northeast China, were investigated for the period 1990-2015. The results revealed significant changes in climate conditions, soil physical properties and cropland use patterns with socioeconomic activities. Trends in climate parameters showed increasing temperature (+0.49°C/decade, p < 0.05) and decreasing wind speed (-0.3 m/s/decade, p < 0.01) for the growing season, while sunshine hours and precipitation exhibited non-significant trends. Four topsoil parameters including soil organic carbon (SOC), clay, bulk density and pH, indicated deteriorating soil conditions across most of the croplands, although some do exhibited slight improvement. The changing amplitude for each of the four above parameters ranged within -0.052 to 0.029 kg C/kg, -0.38 to 0.30, -0.60 to 0.39 g/cm3, -3.29 to 2.34, respectively. Crop production significantly increased (44.0 million tons) with increasing sown area of croplands (~2.5 million ha) and fertilizer application (~2.5 million tons). The study reveals the dynamics of ECC in the Songnen Plain with intensive cultivation from 1990 to 2015. Population growth, economic development, and policy reform are shown to strongly influence the spatiotemporal changes in cropland characteristics. The study potentially provides valuable scientific information to support sustainable agroecosystem management in the context of global climate change and national socioeconomic development.
In order to better understand the quality of newly created farmland (NF) as well as slope and check-dam farmland (CF) soil quality, two typical traditional farmland areas within the hilly and gully region of Chinese Loess Plateau were selected as controls in this analysis. The results of this study initially reveal that pH values for slope farmland (SF) and CF were significantly lower (P < 0.05) than those for NF and that SF values were always greater than those of their CF counterparts. At the same time, cation exchange capacity (CEC) and soil organic matter (SOM) occurred in the following size-decreasing sequence, i.e., CF, SF, and NF. Data also show that long-term planting has resulted in increases in total nitrogen (N), available N, total phosphorus (P), available P, total potassium (K) and available K and has also enhanced concentrations of soil copper (Cu), zinc (Zn), iron (Fe), and manganese (Mg) as well as soil cadmium (Ca), lead (Pb), chromium (Cr), and mercury (Hg). These latter elements occur in the concentration sequence of SF > CF > NF. Overall, results indicate that long-term planting negatively impacts soil health because of the accumulation of toxic heavy metals. This means that farmland planted over longer timescales needs to lie fallow to enable it to rehabilitate while NF requires the addition of organic matter as well as rotational utilization in order to facilitate the development of green agriculture.
Understanding the underlying ecological processes that control plant diversity within (α-diversity) and among (β-diversity) forest gaps is important for managing natural forest ecosystems, and it is also a prerequisite for identifying the formation and maintenance mechanisms of forest plant communities. In this study, we focused on the interrelationships among habitat type (gap/non-gap plots), gap size, elevation and environmental factors, and we explored their effects on plant diversity (α-diversity and β-diversity). To do this, a total of 21 non-gap (i.e., closed canopy) plots (100 m2) and 63 gap plots, including 21 with large gaps (200-410 m2), 21 with medium gaps (100-200 m2) and 21 with small gaps (38.5- 100 m2),were selected along an elevational gradient in a subalpine coniferous forest of southwestern China. Using structural equation models (SEMs), we analyzed how forest gaps affected plant diversity (α-diversity and β-diversity) along an elevational gradient. The results showed that (1) as elevation increased, unimodal patterns of α-diversity were found in different-sized gaps, and β-diversity showed a consistent sinusoidal function pattern in different-sized gaps. The gap size was positively related to α-diversity, but this effect disappeared above 3500 masl. Moreover, the patterns of α-diversity and β-diversity in non-gap plots were irregular along the elevational gradient. (2) SEMs demonstrated that many environmental factors, such as the annual mean air temperature (AMAT), ultraviolet-A radiation (365 nm, UV-A365), ultraviolet-B1 radiation (297 nm, UV-B297), moss thickness (MT), soil carbon/nitrogen ratio (C/N ratio), NH4-N and NO3-N, were significantly affected by elevation, which then affected α-diversity and β-diversity. The photosynthetic photon flux density (PPFD), UV-A365 and UV-B297 were significantly higher in plots with forest gaps than in the non-gap plots. Moreover, the PPFD and UV-A365 were positively and directly affected by gap size. Surprisingly, except for the NH4-N and the C/N ratios, the below-ground environmental factors showed little or no relationships with forest gaps. All of these effects contributed to plant diversity. Overall, the above-ground environmental factors were more sensitive to gap-forming disturbances than the below-ground environmental factors, which affected α-diversity and β-diversity. The predicted pathway in the SEMs of the elevational effects on α-diversity and β-diversity was relatively complicated compared with the effects of forest gaps. These results can provide valuable insights into the underlying mechanisms driving the diversity-habitat relationship in the subalpine coniferous forests of southwestern China.
Ecological corridor networks can efficiently improve regional landscape connectivity. Corridors for multiple faunal species movements are receiving increasing attention and graph theory is considered a promising way to explore landscape connectivity. In Xishuangbanna, the circuit theory was applied to explore the corridor networks for biodiversity for the first time. In addition, disturbances caused by the road network and the protection efficiency of National Nature Reserves and planned area for corridors were evaluated. Results indicated that the regional corridor networks could be estimated using a modified circuit method and Zonation model. Spatially, the key corridors were concentrated in the central-western, southeastern and northern regions. We detected 66 main intersections between key corridors and the road buffer. Of these points, 65% are forest, 23% grassland and 12% farmland. More than half of the area of National Nature Reserves constituted the top 50% of the corridors, and the planned corridor areas could efficiently protect some key corridors. However, these reserves only protected about 17% of regional key corridors, and the corridor conservation area in the western and northern regions were absent. The issues addressed in our study aided in the elucidation of the importance of regional landscape connectivity assessments and operational approaches in conservation planning.
Land is the root of rural revitalization, and its core is to reinvigorate land resources through the building up of land capacity. Since the late 1990s, land consolidation efforts have been widely extended to all parts of China. Land consolidation has served as an essential instrument for reinvigorating stock land, strengthening intensive land use, timely supplementing cultivated land, and promoting agricultural modernization, as well as urban-rural integration. This study uses a typical poor village (Dadao Village) in a state-designated impoverished county (Fuping County, Hebei Province), to analyze the socioeconomic benefits and eco-environmental impacts of land consolidation. With the aid of first-hand data from questionnaire surveys, face-to-face interviews and the visual interpretation of land use and land cover changes (LUCC), we found that: 1) the barren hilly land consolidation (BHLC) helps to promote the transformation of resource-advantages into asset-advantages in poverty-stricken areas. In 2017, 60.16% households in the study area gained the additional transferred-income with an annual average of 2843 yuan, while 19.11% households received the wage-income with an annual average of 9871 yuan. 2) Land consolidation inspires farmers’ enthusiasm to participate in village government and helps alleviate rural poverty. From 2014 to 2017, land consolidation has helped 585 poor in the village out of poverty. Meanwhile, by land consolidation, most farmers’ attitudes towards land consolidation have shifted from “not caring” to “have great concern,” and their identity cognition has gradually changed from being bystanders to becoming decision makers and supervisors. 3) Further analysis demonstrated that land consolidation could not only increase the quantity and quality of arable land, but also have a certain impact on eco-environment. During 2014-2016, the BHLC in the study area transformed 242.12 ha unused barren hilly land and open forest land into well-facilitated arable land, and increased the average arable land by 0.19 ha per capita. Also, the index of land use intensity increased by 27.01% between 2014 and 2016. Farmers’ perceptions of environmental awareness have confirmed that such high-intensity LUCC were significant enough to make two-side impacts on eco-environment. We appeal to establish a combined organization and encouragement mechanism of rural land consolidation, to take the full breadth and depth of farmers’ participation into consideration, and to formulate more scientific and sustainable land consolidation planning. Also, we put forward some suggestions and notes for the implementation and promotion of BHLC model. These findings can provide beneficial references for those involved in policymaking and planning in the areas of land consolidation and poverty alleviation in China, as well as other developing countries around the world.
Rapid peri-urbanization has become a new challenge for sustainable urban-rural development worldwide. To clarify how unprecedented urban sprawl at the metropolitan fringe impacts urban-rural landscape, this study took the Beijing-Tianjin corridor of Beijing-Tianjin-Hebei metropolitan area, one of the largest urban clusters in China, as a typical example. By using Landsat-based landscape metrics and a practical methodology, we investigated the landscape changes and discussed the potential reasons in the context of rapid peri-urbanization of China. Specifically, multi-temporal land use maps derived from Landsat images were used to calculate landscape metrics and analyze their characteristics along the urban-rural gradients. The practical methodology was used to monitor spatio-temporal characteristics of landscape change in large metropolitan areas. The results showed that landscape patterns in the area had changed greatly from 2000 to 2015 with characteristics of construction land sprawl and arable land shrinkage. The intensity and scale of landscape changes varied along the urban-rural gradients. Sampled plots in urbanized areas and rural areas demonstrated distinguishable landscape patterns and significant differences. Urban areas had more heterogeneous and fragmented landscapes than rural areas. Peri-urban areas in general experienced higher levels of land diversification than rural areas. Rural residential land appeared to be more aggregated near Beijing and Tianjin cities. Besides, our findings also indicated that urban expansion was largely responsible for landscape patterns. The findings of this study potentially provide strategical insights into landscape planning around mega cities and sustainable coordinated urban-rural development.
With global climate change, the agricultural light-temperature potential productivity in the agro-pastoral ecotone has increased. This offers a good opportunity to develop agriculture in the agro-pastoral ecotone. However, the agro-pastoral ecotone is also an ecologically fragile area in which land degradation challenges agricultural development. As population grows and the need for food increases, the land carrying capacity of the agro-pastoral ecotone becomes insufficient, and the human-land relationship is not harmonious. Such conditions have limited the agricultural and rural development in the ecotone. The paper demonstrates how land engineering may improve land quality and support agricultural development in the ecotone based on studies at a research station established in 2015 in Yulin, Shaanxi Province, China. The studies target three factors: soil improvement, crop selection, and field management. The results show that: (1) The highest yield of crops planted on improved land is close to or even higher than that achieved under previous crop growth conditions. For instance, the corn yields can exceed 25%. (2) The potatoes grown on the improved land yield the highest gross income, reaching 67,200 yuan/ha. By way of land engineering, input costs can be balanced in 3-5 years. (3) As a result of land engineering, some villages in Yulin City have realized sustainable agricultural and even rural development, and promotion of this model will support the sustainable development of agriculture in the agro-pastoral ecotone.
With basic information from 8353 archaeological sites, this study describes a holistic spatial-temporal distribution pattern of archaeological sites of the prehistoric culture sequence from 9.5 ka BP (ka BP = thousands of years before 0 BP, where “0 BP” is defined as the year AD 1950) to 2.3 ka BP in the region that extends from the Yanshan Mountains to the Liaohe River Plain (i.e., the Yan-Liao region) in northern China. Based on spatial statistics analysis - including the spatial density of the sites and Geographic Information System nearest-neighbour analysis, combined with a review of environmental and climatic data - this paper analyses cultural evolution, the spatial-temporal features of the archaeological sites and human activities against the backdrop of climatic and environmental changes in this region. The results reveal that prehistoric cultural evolution in the Yan-Liao region is extensively influenced by climatic and environmental changes. The Xinglongwa, Zhaobaogou and Fuhe cultures, which primarily developed during a habitable period from 8.5 ka BP to 6.0 ka BP with strong summer monsoons, have similar maximum density values, spatial patterns and subsistence strategies dominated by hunting-gathering. Significant changes occurred in the Hongshan and Lower Xiajiadian cultures, with a significant increase in numbers and densities of sites and a slump in average nearest-neighbour ratio when the environment began to deteriorate starting in 6.0 ka BP. Additionally, with the onset of a weak summer monsoon and the predominance of primitive agriculture, sites of these two cultures present a different type of concentric circle-shaped pattern in space. As the environment continuously deteriorated with increasing aridity and the spread of steppe, more sites were distributed towards the south, and primitive agriculture was replaced by livestock husbandry in the Upper Xiajiadian culture. The most densely populated areas of the studied cultures are centralized within a limited area. The Laohahe River and Jiaolaihe River basins formed the core area in which most archaeological sites were distributed during the strong summer monsoon period and the first few thousand years of the weak summer monsoon period.
Spatio-temporal changes in the differentiation characteristics of eight consecutive phenological periods and their corresponding lengths were quantitatively analyzed based on long-term phenological observation data from 114 agro-meteorological stations in four maize growing zones in China. Results showed that average air temperature and growing degree-days (GDD) during maize growing seasons showed an increasing trend from 1981 to 2010, while precipitation and sunshine duration showed a decreasing trend. Maize phenology has significantly changed under climate change: spring maize phenology was mainly advanced, especially in northwest and southwest maize zones, while summer and spring-summer maize phenology was delayed. The delay trend observed for summer maize in the northwest maize zone was more pronounced than in the Huang-Huai spring-summer maize zone. Variations in maize phenology changed the corresponding growth stages length: the vegetative growth period (days from sowing date to tasseling date) was generally shortened in spring, summer, and spring-summer maize, although to different degrees, while the reproductive growth period (days from tasseling date to mature date) showed an extension trend. The entire growth period (days from sowing date to mature date) of spring maize was extended, but the entire growth periods of summer and spring-summer maize were shortened.
The concepts of regional resources and environmental carrying capacity are important aspects of both academic inquiry and government policy. Although notable results have been achieved in terms of evaluating both these variables, most researchers have utilized a traditional analytical method that incorporates the “pressure-state-response” model. A new approach is proposed in this study for the comprehensive evaluation of regional resources and environmental carrying capacity; applying a “pressure-support”, “destructiveness-resilience”, and “degradation-promotion” (“PS-DR-DP”) hexagon interaction theoretical model, we divided carrying capacity into these three pairs of interactive forces which correspond with resource supporting ability, environmental capacity, and risk-disaster resisting ability, respectively. Negative carrying capacity load in this context was defined to include pressure, destructiveness, and degradation, while support, resilience, and promotion comprised positive attributes. The status of regional carrying capacity was then determined via the ratio between positive and negative contribution values, expressed in terms of changes in both hexagonal shape and area that result from interactive forces. In order to test our “PS-DR-DP” theory-based model, we carried out a further empirical study on Beijing over the period between 2010 and 2015. Analytical results also revealed that the city is now close to attaining a perfect state for both resources and environmental carrying capacity; the latter state in Beijing increased from 1.0143 to 1.1411 between 2010 and 2015, an improved carrying capacity despite the fact that population increased by two million. The average contribution value also reached 0.7025 in 2015, indicating that the city approached an optimal loading threshold at this time but still had space for additional carrying capacity. The findings of our analysis provide theoretical support to enable the city of Beijing to control population levels below 23 million by 2020.
Plant moisture content (PMC) is used as an indicator of forest flammability, which is assumed to be affected by climate drought. However, the fire-induced drought stress on PMC and its spatial and temporal variations are unclear. Based on a parallel monitoring experiment from 2014 to 2015, this study compared the PMCs and soil moisture contents (SMC) at five post-fire sites in central Yunnan Plateau, Southwest China. The number of years since last fire (YSF), season, topographic position, plant species and tissue type (leaf and branch) were selected as causal factors of the variations in PMC and SMC. A whole year parallel monitoring and sampling in the post-fire communities of 1, 2, 5, 11 and 30 YSF indicated that drought stress in surface soils was the strongest in spring within the first 5 years after burning, and the SMC was regulated by topography, with 64.6% variation in soil moisture accounted for by YSF (25.7%), slope position (22.1%) and season (10.8%). The temporal variations of PMC and SMC differed at both interannual and seasonal scales, but the patterns were consistent across topographic positions. PMC differed significantly between leaves and branches, and among three growth-forms. The mean PMC was lower in broad-leaved evergreen species and higher in conifer species. Season and soil temperature were the primary determinants of PMC, accounting for 19.1% and 8.3% of variation in PMC, respectively. This indicated phenology-related growth rather than drought stress in soil as the primary driver of seasonal changes in PMC. The significant variations of PMC among growth forms and species revealed that seasonal soil temperature change and dominant species in forest communities are useful indicators of fire risk assessment in this region.
The terrestrial hydrological process is an essential but weak link in global/regional climate models. In this paper, the development status, research hotspots and trends in coupled atmosphere-hydrology simulations are identified through a bibliometric analysis, and the challenges and opportunities in this field are reviewed and summarized. Most climate models adopt the one-dimensional (vertical) land surface parameterization, which does not include a detailed description of basin-scale hydrological processes, particularly the effects of human activities on the underlying surfaces. To understand the interaction mechanism between hydrological processes and climate change, a large number of studies focused on the climate feedback effects of hydrological processes at different spatio-temporal scales, mainly through the coupling of hydrological and climate models. The improvement of the parameterization of hydrological process and the development of large-scale hydrological model in land surface process model lay a foundation for terrestrial hydrological-climate coupling simulation, based on which, the study of terrestrial hydrological-climate coupling is evolving from the traditional unidirectional coupling research to the two-way coupling study of “climate-hydrology” feedback. However, studies of fully coupled atmosphere-hydrology simulations (also called atmosphere-hydrology two-way coupling) are far from mature. The main challenges associated with these studies are: improving the potential mismatch in hydrological models and climate models; improving the stability of coupled systems; developing an effective scale conversion scheme; perfecting the parameterization scheme; evaluating parameter uncertainties; developing effective methodology for model parameter transplanting; and improving the applicability of models and high/super-resolution simulation. Solving these problems and improving simulation accuracy are directions for future hydro-climate coupling simulation research.
Urbanization can profoundly influence the ecosystem service for biodiversity conservation. However, few studies have investigated this effect, which is significant for maintaining regional sustainable development. We take the rapidly developing, mountainous and biodiversity hotspot region, Jinghong, in southern Yunnan Province as the case study. An integrated ecosystem service model (PANDORA) is used to evaluate this regional BESV (ecosystem service value for biodiversity conservation). The modeled BESV is sensitive to landscape connectivity changes. From the 1970s to 2010, regional urban lands increased from 18.64 km2 to 36.81 km2, while the BESV decreased from $6.08 million year-1 to $5.32 million year-1. Along with distance gradients from the city center to the fringe, BESV varies as an approximate hump-shaped pattern. Because correlation analysis reveals a stronger influence of landscape composition on spatial BESV estimates than the landscape configuration does, we conclude that the projected urban expansion will accelerate the BESV reduction. Of the projected urban land, 95% will show a decreasing BESV trend by approximately $2 m-2 year-1. To prevent this, we recommend compact urban planning for the mountainous city.
The Interconnected River System Network (IRSN) plays a crucial role in water resource allocation, water ecological restoration and water quality improvement. It has become a key part of the urban lake management. An evaluation methodology system for IRSN project can provide important guidance for the selection of different water diversion schemes. However, few if any comprehensive evaluation systems have been developed to evaluate the hydrodynamics and water quality of connected lakes. This study developed a comprehensive evaluation system based on multi-indexes including aspects of water hydrodynamics, water quality and socioeconomics. A two-dimensional (2-D) mathematical hydrodynamics and water quality model was built, using NH3-N, TN and TP as water quality index. The IRSN project in Tangxun Lake group was used as a testbed here, and five water diversion schemes were simulated and evaluated. Results showed that the IRSN project can improve the water fluidity and the water quality obviously after a short time of water diversion, while the improvement rates decreased gradually as the water diversion went on. Among these five schemes, Scheme V showed the most noticeable improvement in hydrodynamics and water quality, and brought the most economic benefits. This comprehensive evaluation method can provide useful reference for the implementation of other similar IRSN projects.
Mountains in western China, hosted rich biodiversity and millions of people and inhabitant with vital ecosystem services, had experienced the most serious biodiversity loss with fragile ecological problems. Even though increasing attentions had been paid to this issue, we still lacked efficient methods to assess the change of plant biodiversity at medium/large scale due to the poor data and co-existing multiple habitat types. This study proposed an integrated method combining InVEST-habitat quality model, NPP and landscape pattern indexes to analyze the spatial heterogeneity of plant biodiversity and its spatiotemporal change on raster cell scale. The results indicated that plant biodiversity service was high in Bailongjiang watershed with obvious spatial pattern variations. The land area containing higher plant biodiversity were 3161 km2, which mainly distributed in the National Nature Reserve and forestry area. While the areas with lower plant biodiversity accounted for 37.67% and mainly distributed in the valleys between Zhouqu-Wudu-Wenxian County, the valley of Minjiang in Tanchang County and alpine mountain snow-covered regions. During 1990-2010, plant biodiversity level tended to increase and the higher plant biodiversity area increased from 14.13% to 17.15% due to ecological restoration and afforestation, while plant biodiversity decreased in the area with intensive human activities, such as cultivated land, urban and rural land. The results showed that combining InVEST-habitat quality model, NPP and landscape pattern indexes can effective reveal mountain plant biodiversity change. The study was useful for plant biodiversity conservation policy-making and human activity management for the disaster-impacted mountainous areas in China.