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Agroecosystem transformation and its driving factors in karst mountainous areas of Southwest China: The case of Puding County, Guizhou Province
Puding County in central Guizhou is a typical karst ecologically vulnerable area integrating rural, mountainous, and ecological migration areas. It is essential to study the dynamic trajectory and direction of its agroecosystems (AESs) transformation to promote sustainable land use development in karst mountain areas. Based on high-resolution remote sensing images from 2004 to 2020, this study analyzes the transformation characteristics, typical landscape patterns, and their driving forces of AESs using the landscape pattern index, moving window method, and Geodetector model. The results show that: (i) The overall landscape pattern of AESs in the study area developed towards complexity and diversification from 2004 to 2020. The overall trend of woodland and grassland (WGL) is increasing, the slope cultivated land (SCL) is shrinking, the construction land (CL) is spreading and expanding along the vicinity of the town, and the economic and fruit forests (EFF) are increasing significantly. (ii) Three typical patterns are concluded according to the main transformation directions of AESs: WGL restoration type, CL growth type, and EFF growth type; middle and high mountains are dominated by the WGL restoration type with increased ecological functions, and the concentration of the new WGL increases with the increase in elevation; low mountain areas are dominated by the CL growth type with enhanced living functions, and the concentration of the new CL decreases with the increase in slope and elevation; valleys and hills are dominated by the EFF growth type with enhanced ecological and economic functions, and the concentration of the new EFF increases with the decrease in slope and elevation. (iii) Socio-economic factors are the dominant drivers of AES transformation. The WGL restoration type is dominated by slope and elevation, the CL growth type is mainly influenced by slope and urbanization rate, and the EFF growth type is primarily influenced by soil organic matter, slope, urbanization rate, and resident population. The study results have implications for rural land use, rural development, and ecological restoration of rocky desertification in karst mountain areas and other similar mountainous areas.
Food systems are responsible for pushing human resource use past three thresholds of safe planetary operating space, yet the potential of agroecosystems to contribute to sustainability of food systems when managed for multiple benefits is underexplored. This gap has led to a call for food systems transformation. Previous reviews have acknowledged that governance of food systems transformations is not well understood. The aim of this review is to examine the challenges to transformative governance of agroecosystems, and the potential to apply existing paradigms of adaptiveness in agroecosystems for this transformation. Agricultural production landscapes have been found to be a key level of governance for realizing sustainability transformations of food systems and the landscape concept has been a key paradigm for managing multiple social and ecological objectives at a landscape scale. An examination of the landscape concept using five transformative governance characteristics and applying the earth system governance research lenses illustrated two key areas for further investigation and action for transformative governance. The first is landscape design for continuous social and ecological changes and evolving understandings of sustainability, and the second is the allocation of landscape costs, rights and benefits in present and future decision-making and among human and non-human entities. Managing the pluralistic diversities inherent to agroecosystems will be a key dynamic important to governance and policy for food systems transformations.
Agroforestry provides essential ecosystem services; its structure and stability directly determine ecosystem function and service provision. Sustaining agroforestry ecosystem functions and services in the long term is necessary to meet the needs of people. This study conducted a literature search and statistical analysis based on WOS and CNKI literature databases. We reviewed 136 literature reports on studies of agroforestry ecosystem structure and stability. The landmark results are summarized in five aspects of agroforestry ecosystems: structure characteristics, structure optimization, structure design, stability research, and influence factors. On this basis, the key scientific issues that need to be solved are summarized, and their insights for improving the supply capacity of agroforestry ecosystem services under the rocky desertification control are discussed.
The research on land use transformation has attracted more and more attention, and there are few research results on the eco-environmental effects of regional land use change from the perspective of land use function transformation. From the perspective of production-living-ecological land use function classification, this paper obtained land use change data of Shaanxi Province in 2000, 2010, and 2020, calculated the land use transfer matrix, ecological environment quality index, and ecological contribution rate of land use transformation, and quantitatively analyzed the temporal and spatial evolution of production-living-ecological spaces and the eco-environmental effects of land use structure transformation in Shaanxi Province. The results showed that the land use change in Shaanxi Province is mainly manifested in the continuous increase of ecological and living land area and the continuous decrease of production land area from 2000 to 2020. In the transformation of land use structure in Shaanxi Province, the biggest change in area is the mutual transformation between productive cultivated land and ecological grassland land. The occupation of ecological grassland land by other land types is an important factor leading to the decline of ecological environment quality. Overall, the ecological environment of Shaanxi Province has shown a trend of improvement in the past two decades. Quantitative research on the transformation characteristics of land use structure and its ecological environment effects in the past two decades is conducive to providing data support for the promotion of ecological civilization construction in Shaanxi Province.
This study analyzed land use/cover dynamics in the mountain landscape of Tara Gedam and adjacent agro-ecosystem of northwest Ethiopia over a period of 46 years (1957-2003). The changes were measured through interpretation of aerial photographs taken in 1957 and 1980, and Land-sat satellite image of 2003 using Arc GIS 9.2 software, supported by focal group discussions and field visits. Three separate maps (for years 1957, 1980 and 2003) of the study area were produced and six major land use/cover classes were identified: dense forest, woodland, shrub land, grassland, riverine vegetation and cultivated and settlement land. The results indicated that the main land trajectory was from natural vegetation cover to settlement and cultivated land. The cultivated and settlement land coverage increased by 90.60% between 1957 and 2003. However, woodland, dense forest, riverine vegetation, shrub and grasslands coverage declined by 97.87, 71.04, 37.00, 9.02 and 3.03%, respectively. These could be mainly attributed to anthropogenic factors. Increasing demands of more land for cultivation and settlement, overgrazing, deforestation for fuel wood and construction have resulted in a dramatic shrinkage of the area under natural vegetation. The 1975 national land reform proclamation of the country had also contributed to the expansion of cultivated and settlement land. The implications of these changes are increased land degradation and loss of biodiversity affecting the livelihood of the community. It is suggested that the study area needs an immediate intervention for developing sustainable land use practices and to manage the remaining natural vegetation and to rehabilitate the degraded lands.
Excessive nitrogen and phosphorus inputs to land and subsequent export to water via runoff leads to aquatic ecosystem deterioration. The WRB is the world’s largest karst basin which is characterized by a fragile ecosystem coupling with high population pressure, and the transformation of intensive agriculture. Quantifying different sources of pollution in karst regions is challenging due to the complexity of landscape topography and geology coupled with high transmissivity and connectivity of subsurface hydrological systems. This results in large uncertainty associated with nitrogen (N) and phosphorus (P) flow pathways. This combination of factors contributes to the WRB being a high priority for quantitatively understanding the contribution of regional nutrient inputs and those of other major water quality determinants. Here we applied the latest statistical data (2000–2018) and simple quasi-mass-balance methods of net anthropogenic nitrogen and phosphorus inputs (NANI and NAPI) to estimate spatio-temporal heterogeneity of N and P inputs. The results show that while NANI and NAPI are first decreasing, this is followed by an increasing trend during 2000–2018, with average values of 11262.06 ± 2732 kg N km− 2 yr⁻¹ and 2653.91 ± 863 kg P km⁻² yr⁻¹ respectively. High N and P concentrations in the river drainage network are related to the spatial distribution of excessive inputs of N and P. Rapid urbanization, livestock farming and the conflicts between economic development and lagged-environmental management are the main reasons for the incremental regional N and P inputs. Management decisions on nutrient pollution in karst regions need careful consideration to reduce ecological impacts and contamination of karst aquifers. This study provides new insight for policy and decision making in the WRB, highlighting policy options for managing nutrient inputs and providing recommendations for closing the science-policy divide.
To determine the risk state distribution, risk level, and risk evolution situation of agricultural non-point source pollution (AGNPS), we built an ‘Input-Translate-Output’ three-dimensional evaluation (ITO3dE) model that involved 12 factors under the support of GIS and analyzed the spatiotemporal evolution characteristics of AGNPS risks from 2005 to 2015 in Chongqing by using GIS space matrix, kernel density analysis, and Getis-Ord Gi* analysis. Land use changes during the 10 years had a certain influence on the AGNPS risk. The risk values in 2005, 2010, and 2015 were in the ranges of 0.40–2.28, 0.41–2.57, and 0.41–2.28, respectively, with the main distribution regions being the western regions of Chongqing (Dazu, Jiangjin, etc.) and other counties such as Dianjiang, Liangping, Kaizhou, Wanzhou, and Zhongxian. The spatiotemporal transition matrix could well exhibit the risk transition situation, and the risks generally showed no changes over time. The proportions of ‘no-risk no-change’, ‘low-risk no-change’, and ‘medium-risk no-change’ were 10.86%, 33.42%, and 17.25%, respectively, accounting for 61.53% of the coverage area of Chongqing. The proportions of risk increase, risk decline, and risk fluctuation were 13.45%, 17.66%, and 7.36%, respectively. Kernel density analysis was suitable to explore high-risk gathering areas. The peak values of kernel density in the three periods were around 1110, suggesting that the maximum gathering degree of medium-risk pattern spots basically showed no changes, but the spatial positions of high-risk gathering areas somehow changed. Getis-Ord Gi* analysis was suitable to explore the relationships between hot and cold spots. Counties with high pollution risks were Yongchuan, Shapingba, Dianjiang, Liangping, northwestern Fengdu, and Zhongxian, while counties with low risks were Chengkou, Wuxi, Wushan, Pengshui, and Rongchang. High-value hot spot zones gradually dominated in the northeast of Chongqing, while low-value cold spot zones gradually dominated in the Midwest. Our results provide a scientific base for the development of strategies to prevent and control AGNPS in Chongqing.
Google Earth Engine (GEE) is a cloud-based geospatial processing platform for large-scale environmental monitoring and analysis. The free-to-use GEE platform provides access to (1) petabytes of publicly available remote sensing imagery and other ready-to-use products with an explorer web app; (2) high-speed parallel processing and machine learning algorithms using Google's computational infrastructure; and (3) a library of Application Programming Interfaces (APIs) with development environments that support popular coding languages , such as JavaScript and Python. Together these core features enable users to discover, analyze and visualize geospatial big data in powerful ways without needing access to supercomputers or specialized coding expertise. The development of GEE has created much enthusiasm and engagement in the remote sensing and geospatial data science fields. Yet after a decade since GEE was launched, its impact on remote sensing and geospatial science has not been carefully explored. Thus, a systematic review of GEE that can provide readers with the "big picture" of the current status and general trends in GEE is needed. To this end, the decision was taken to perform a meta-analysis investigation of recent peer-reviewed GEE articles focusing on several features, including data, sensor type, study area, spatial resolution, application, strategy, and analytical methods. A total of 349 peer-reviewed articles published in 146 different journals between 2010 and October 2019 were reviewed. Publications and geographical distribution trends showed a broad spectrum of applications in environmental analyses at both regional and global scales. Remote sensing datasets were used in 90% of studies while 10% of the articles utilized ready-to-use products for analyses. Optical satellite imagery with medium spatial resolution, particularly Landsat data with an archive exceeding 40 years, has been used extensively. Linear regression and random forest were the most frequently used algorithms for satellite imagery processing. Among ready-to-use products, the normalized difference vegetation index (NDVI) was used in 27% of studies for vegetation, crop, land cover mapping and drought monitoring. The results of this study confirm that GEE has and continues to make substantive progress on global challenges involving process of geo-big data.
The Three Gorges Reservoir Area (TGRA) is typical of an ecologically vulnerable area, comprised of rural and mountainous areas, and with high immigration. Because of its economic and ecologic importance, studying the traditional agroecosystem changes in the TGRA is key to rural development and revitalization. In this study, we apply a framework of theoretical analysis, empirical study, and trend prediction to the Caotangxi River watershed within the TGRA. Using QuickBird high-resolution remote sensing images from 2012 to 2017 to evaluate natural resources and farmers’ behavior, we analyze the transition and trends in the traditional agroecosystem in mountainous areas of the TGRA at spatial scale of the man-land relationship. We find that the agroecosystem in the TGRA can be divided into four modes using 100 m interval buffer rings: high-low-low, high-low-high, low-high-low and low-low-high mode where the different modes represent the agricultural development stages in the TGRA. Furthermore, the traditional agroecosystem in TGRA, represented by system elements such as farmers and sloping farmland, is transforming to accommodate the diversification of farmer livelihoods. For example, sloping farmland, which was dominated by a production function, now has equal emphasis on ecological and economic functions. Spatially, the range of the agroecosystem transition has migrated beyond high mountain areas to flat valley areas. Generally, this study provides an overview of land use in rural areas, controls on soil and water loss in mountainous areas, and better rural living environments in the TGRA.
In the past several decades, North and South Dakota have experienced increased agricultural expansion and crop rotation simplification, namely an increase in corn (Zea mays L.)– soybean [Glycine max (L.) Merr.] systems. This review investigates the nature and extent of those changes, the underlying causes, and the consequences they have on ecosystem services. The framework of ecosystem services is underutilized in agricultural research, but it can be used to describe the sustainability, resistance, and resilience of the system in relation to these land use changes. The current trends are focused on maximizing provisioning services (i.e., food and fuel) at the expense of regulating, cultural, and supporting services. The decline of regulating services can be seen in increased peak river flow (up to 100% and 200% increases in South and North Dakota, respectively), as well as by the 100% increase in area treated by chemicals, partially due to diminished bioregulation of pests and weeds. The effects on supporting services are demonstrated by altered C balances and water cycling, while the loss of cultural connection to the land is evidenced by a 40% decrease in land conservation since 1997. Overall, these changes are making the land in North and South Dakota more susceptible to stressors, such as drought, crop pests, or even economic trends that could greatly harm these agroecosystems and have nationwide ramifications. To address these changes, producers need to provide a balance of agroecosystem services by optimizing currently available management strategies and possibly transforming agricultural practices for long‐term system stability.
Satellite data show increasing leaf area of vegetation due to direct factors (human land-use management) and indirect factors (such as climate change, CO2 fertilization, nitrogen deposition and recovery from natural disturbances). Among these, climate change and CO2 fertilization effects seem to be the dominant drivers. However, recent satellite data (2000–2017) reveal a greening pattern that is strikingly prominent in China and India and overlaps with croplands world-wide. China alone accounts for 25% of the global net increase in leaf area with only 6.6% of global vegetated area. The greening in China is from forests (42%) and croplands (32%), but in India is mostly from croplands (82%) with minor contribution from forests (4.4%). China is engineering ambitious programmes to conserve and expand forests with the goal of mitigating land degradation, air pollution and climate change. Food production in China and India has increased by over 35% since 2000 mostly owing to an increase in harvested area through multiple cropping facilitated by fertilizer use and surface- and/or groundwater irrigation. Our results indicate that the direct factor is a key driver of the ‘Greening Earth’, accounting for over a third, and probably more, of the observed net increase in green leaf area. They highlight the need for a realistic representation of human land-use practices in Earth system models.
Microbial biopesticides include several microorganisms like bacteria, fungi, baculoviruses, and nematode-associated bacteria acting against invertebrate pests in agro-ecosystems. The biopesticide sector is experiencing a significant growth and many discoveries are being developed into new biopesticidal products that are fueling a growing global market offer. Following a few decades of successful use of the entomopathogenic bacterium Bacillus thuringiensis and a few other microbial species, recent academic and industrial efforts have led to the discovery of new microbial species and strains, and of their specific toxins and virulence factors. Many of these have, therefore, been developed into commercial products. Bacterial entomopathogens include several Bacillaceae, Serratia, Pseudomonas, Yersinia, Burkholderia, Chromobacterium, Streptomyces, and Saccharopolyspora species, while fungi comprise different strains of Beauveria bassiana, B. brongniartii, Metarhizium anisopliae, Verticillium, Lecanicillium, Hirsutella, Paecilomyces, and Isaria species. Baculoviruses are species-specific and refer to niche products active against chewing insects, especially Lepidopteran caterpillars. Entomopathogenic nematodes (EPNs) mainly include species in the genera Heterorhabditis and Steinernema associated with mutualistic symbiotic bacteria belonging to the genera Photorhabdus and Xenorhabdus. An updated representation of the current knowledge on microbial biopesticides and of the availability of active substances that can be used in integrated pest management programs in agro-ecosystems is reported here.
Above-ground vegetation biomass is one of the major carbon sinks and provides both provisioning (e.g., forestry products) and regulating ecosystem services (by sequestering carbon). Continuing deforestation and climate change threaten this natural resource but can effectively be countered by national conservation policies. Here we present time series (1999-2017) derived from complementary satellite systems to describe a phenomenon of global significance: the greening of South China Karst. We find a major increase in growing season vegetation cover from 69% in 1999 to 81% in 2017 occurring over ~1.4 million km². Over 1999-2012, we report one of the globally largest increases in biomass to occur in the South China Karst region (on average +4% over 0.9 million km²), which accounts for ~5% of the global areas characterized with increases in biomass. These increases in southern China's vegetation have occurred despite a decline in rainfall (-8%) and soil moisture (-5%) between 1999 and 2012 and are derived from effects of forestry and conservation activities at an unprecedented spatial scale in human history (~20,000 km² yr⁻¹ since 2002). These findings have major implications for the provisioning of ecosystem services not only for the Chinese karst ecosystem (e.g., carbon storage, water filtration, and timber production) but also for the study of global carbon cycles.
Afforestation and reforestation projects in the karst regions of southwest China aim to combat desertification and improve the ecological environment. However, it remains unclear at what scale conservation efforts have impacted on carbon stocks and if vegetation regrowth occurs at a large spatial scale as intended. Here we use satellite time series data and show a widespread increase in leaf area index (a proxy for green vegetation cover), and aboveground biomass carbon, which contrasted negative trends found in the absence of anthropogenic influence as simulated by an ecosystem model. In spite of drought conditions, aboveground biomass carbon increased by 9% (+0.05 Pg C y−1), mainly in areas of high conservation effort. We conclude that large scale conservation projects can contribute to a greening Earth with positive effects on carbon sequestration to mitigate climate change. At the regional scale, such ecological engineering projects may reduce risks of desertification by increasing the vegetation cover and reducing the ecosystem sensitivity to climate perturbations. Since 2000, China has attempted to vegetate huge portions of eroded landscape in its south west, bordering Vietman, Laos, and Myanmar. This study finds that this ecological engineering is combating desertification as vegetation regrows and stores carbon.
According to the agroecological approach, energy analyses applied to agriculture should provide information about the structure and functions of the agroecosystem; in other words, about the maintenance of its fund elements, which sustain the flow of ecosystem services. To this end, we have employed a methodological proposal that adds agroecological EROIs to the existing economic EROIs. This methodology is applied here for the first time at the country level, and over a long-term historical period. The Spanish agroforestry sector, which is representative of Mediterranean agroclimatic conditions, has been studied on a decadal basis from 1900 to 2008, fully spanning its process of industrialization and modernization. The results show the loss of energy efficiency brought about by the industrialization of Spanish agriculture. The economic EROIs (FEROI, EFEROI and IFEROI) fell by 42, 93 and 12%, respectively. The shift towards livestock production and the dramatic increase in industrial inputs are the causes of this decline. With regard to agroecological EROIs, NPPact EROI and Biodiversity EROI fell by 6 and 15%, respectively. This suggests that the fund elements are being degraded and alerts us to low returns to nature in the form of un-harvested biomass available to aboveground and underground wildlife. Finally, Woodening EROI increased by 48%. Sixty percentage of this increment was due to the growth of woodland in areas freed from agricultural activities. However, this change in land use was partly due to feed imports from third countries where deforestation processes may well be taking place, an effect that has not been considered in the analysis.
To alleviate the severe rocky desertification and improve the ecological conditions in Southwest China, the national and local Chinese governments have implemented a series of Ecological Restoration Projects since the late 1990s. In this context, remote sensing can be a valuable tool for conservation management by monitoring vegetation dynamics, projecting the persistence of vegetation trends and identifying areas of interest for upcoming restoration measures. In this study, we use MODIS satellite time series (2001–2013) and the Hurst exponent to classify the study area (Guizhou and Guangxi Provinces) according to the persistence of future vegetation trends (positive, anti-persistent positive, negative, anti-persistent negative, stable or uncertain). The persistence of trends is interrelated with terrain conditions (elevation and slope angle) and results in an index providing information on the restoration prospects and associated uncertainty of different terrain classes found in the study area. The results show that 69% of the observed trends are persistent beyond 2013, with 57% being stable, 10% positive, 5% anti-persistent positive, 3% negative, 1% anti-persistent negative and 24% uncertain. Most negative development is found in areas of high anthropogenic influence (low elevation and slope), as compared to areas of rough terrain. We further show that the uncertainty increases with the elevation and slope angle, and areas characterized by both high elevation and slope angle need special attention to prevent degradation. Whereas areas with a low elevation and slope angle appear to be less susceptible and relevant for restoration efforts (also having a high uncertainty), we identify large areas of medium elevation and slope where positive future trends are likely to happen if adequate measures are utilized. The proposed framework of this analysis has been proven to work well for assessing restoration prospects in the study area, and due to the generic design, the method is expected to be applicable for other areas of complex landscapes in the world to explore future trends of vegetation.
The intermeshing of disciplines from the natural sciences, social sciences, engineering and management has become essential to addressing today's environmental challenges. Yet, this can be a daunting task because experts from different disciplines may conceptualize the problems in very different ways and use vocabularies that may not be well understood by one another. This paper explores three alternative environmental concepts used in transdisciplinary research, and outlines some of the epistemological and practical problems that each one poses. It pays particular attention to the increasingly popular concept of "circular economy", and contrasts it with the more commonly-used concepts of "environmental sciences" and "sustainable development". In clarifying the nature, meaning and inter-relationship of these alternative concepts, the paper helps trans-disciplinary researchers to understand the opportunities and challenges associated with each one.
Historically, farmers and hunter-gatherers relied directly on ecosystem services, which they both exploited and enjoyed. Urban populations still rely on ecosystems, but prioritize non-ecosystem services (socioeconomic). Population growth and densification increase the scale and change the nature of both ecosystem- and non-ecosystem-service supply and demand, weakening direct feedbacks between ecosystems and societies and potentially pushing social-ecological systems into traps that can lead to collapse. The interacting and mutually reinforcing processes of technological change, population growth and urbanization contribute to over-exploitation of ecosystems through complex feedbacks that have important implications for sustainable resource use.
The Southwest China Karst, the largest continuous karst zone in the world, has suffered serious rock desertification due to the large population pressure in the area. Recent trend analyses have indicated general greening trends in this region. The region has experienced mild climate change, and yet significant land use changes, such as afforestation and reforestation. In addition, out-migration has occurred. Whether climate change or human-induced factors, i.e., ecological afforestation projects and out-migration have primarily promoted forest restoration in this region was investigated in this study, using Guizhou Province as the study area. Based on Moderate-Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data, we found general greening trends of the forest from 2000 to 2010. About 89% of the forests have experienced an increase in the annual NDVI, and among which, about 41% is statistically significant. For the summer season, more than 65% of the forests have increases in summer NDVI, and about 16% of the increases are significant. The strongest greening trends mainly occurred in the karst areas. Meanwhile, annual average and summer average temperature in this region have increased and the precipitation in most of the region has decreased, although most of these changes were not statistically significant (p > 0.1). A site-based regression analysis using 19 climate stations with minimum land use changes showed that a warming climate coupled with a decrease in precipitation explained some of the changes in the forest NDVI, but the results were not conclusive. The major changes were attributed to human-induced factors, especially in the karst areas. The implications of an ecological afforestation project and out-migration for forest restoration were also discussed, and the need for further investigations at the household level to better understand the out-migration–environment relationship was identified.
Taking departure in the theory of resilience in social-ecological systems, we present an analysis and discussion of how resilience theory can be applied to agroecosystems. Building on the premise that agroecosystems are too complex for resilience to be measured in any precise manner, we delineate behavior-based indicators of resilience within agroecosystems. Based on a review of relevant literature, we present and discuss an index of 13 such indicators, which, when identified in an agroecosystem, suggest that it is resilient and endowed with the capacity for adaptation and transformation. Absence of these indicators identifies points of intervention for managers and stakeholders to build resilience where there is vulnerability. The indicators encompass various phases in the adaptive cycle and seek to link core aspects of social-ecological systems. We stress the strong societal need for building resilience in agroecosystems and advocate for a broader way of evaluating resilience in agroecosystems
Karst rocky desertification is a geo-ecological problem in Southwest China. The rocky desertification risk zone delineation
could be used as a guide for the regional and hierarchical rocky desertification management and prevention. We chose the middle
and lower reaches of the Houzhai underground basin on the karst plateau in Puding County, Guizhou Province, China as the study
area and selected land use type, elevation, slope, aspect, lithology and settlement buffer as the main driving factors of
the rocky desertification. The potential risk of rocky desertification was quantified with the factor-weights union method
and statistical analysis method. Five grades of rocky desertification risk were delineated based on Geographic Information
System. The extremely low, low, moderate, high and extremely high rocky desertification risk zones accounted for 5.01%, 44.17%,
33.92%, 15.59% and 1.30%, respectively. As a whole, the rocky desertification risk level was moderate because the area of
low and moderate rocky desertification risk zones occupied 78.09% of the study area. However, more than half of the area (about
50.81%) was predicted to have moderate rocky desertification risk and above, indicating that the study area was subject to
rocky desertification. Rocky desertification risk was higher in the southeast and lower in the northwest of the study area.
Distinct differences in the distribution of rocky desertification risk zones corresponding to different factors have been
found.
It has been suggested that species richness in agricultural ecosystems depends on both landscape heterogeneity and farm management, but how these factors affect species composition is still poorly understood. In this study, we investigated the species composition of plants, butterflies, and carabid beetles in three different habitats (cereal fields, leys, and semi-natural pastures) in relation to farm management (conventional vs. organic) and landscape complexity at 16 farms in south-eastern Sweden. The farms were divided into eight pairs of one conventional and one organic farm based on land use, location, and landscape features to enable us to separate the effects of landscape features and farm management on species composition. Habitat type explained most of the variation in species composition of butterflies, carabids, and plants. Landscape features in the surrounding landscape explained additional variation, but little relative to habitat, in species composition. The effect of landscape features was larger in the disturbed habitats (cereal fields and ley) than in the more stable semi-natural pastures. Moreover, the effect of landscape features was largest for the most mobile group, butterflies, and least for the sessile plants. The percentage of ley (land temporarily with perennial grass and clover) was the most important landscape feature for butterfly and plant species composition, whereas landscape heterogeneity was the most important landscape feature for carabid species composition. Farm management explained some additional variation in species composition of carabids and butterflies, but it was of minor importance compared to landscape features for species composition of butterflies and plants. We classified the species as common or rare, but for no taxa were common or rare species associated with any landscape feature or farm management.
Information on land cover distribution at regional and global scales has become fundamental for studying global changes affecting ecological and climatic systems. The remote sensing community has responded to this increased interest by improving data quality and methodologies for extracting land cover information. However, in addition to the advantages provided by satellite products, certain limitations exist that need to be objectively quantified and clearly communicated to users so that they can make informed decisions on whether and how land cover products should be used. Accuracy assessment is the procedure used to quantify product quality. Some aspects of accuracy assessment for evaluating four global land cover maps over Canada are discussed in this paper. Attempts are made to quantify limiting factors resulting from the coarse spatial resolution of data used for generating land cover information at regional and global levels. Sub-pixel fractional error matrices are introduced as a more appropriate way for assessing the accuracy of mixed pixels. For classification with coarse spatial resolution data, limitations of the classification method produce a maximum achievable accuracy defined as the average percent fraction of dominant land cover of all pixels in the mapped area. Relationships among spatial resolution, landscape heterogeneity and thematic resolution were studied and reported. Other factors that can affect accuracy, such as misregistration and legend conversion, are also discussed.
Ecology may benefit from long term, large scale experiments on low intensity farming to test theoretical principles and convert them into practical lessons. One century of land conversion in the Argentine pampas, and its effect on critical ecological properties, were analysed and discussed. Land transformation has resulted in significant changes of land use, land cover, energy flow, nutrient dynamics, hydrology, and the trade-offs between productivity, stability and sustainability. The analytical procedure involved the complementary utilisation of different data sources and approaches. The study was focused on large geographical scales: the entire pampas and its five ecoregions. Results were interpreted under the theoretical framework of succession in ecology. The historical conversion of natural grasslands into cultivated grasslands and croplands was not homogeneous, determining a variety of land use and land cover patterns. Due to its higher productivity, much more energy, nutrients and water were mobilised in the rolling pampas than in the other ecoregions. This study provides lessons about how the energy flow, the nutrient dynamics and the hydrological process are modified by land transformation under low external-input conditions. Technical coefficients to be applied in emerging fields of environment administration such as ecological-monitoring, environmental accounting and auditing, agro-ecological certification, land evaluation and allocation, and land management, can also be supplied by this kind of studies.
The global challenge of meeting increased food demand and protecting environmental quality will be won or lost in cropping systems that produce maize, rice, and wheat. Achieving synchrony between N supply and crop demand without excess or deficiency is the key to optimizing trade-offs amongst yield, profit, and environmental protection in both large-scale systems in developed countries and small-scale systems in developing countries. Setting the research agenda and developing effective policies to meet this challenge requires quantitative understanding of current levels of N-use efficiency and losses in these systems, the biophysical controls on these factors, and the economic returns from adoption of improved management practices. Although advances in basic biology, ecology, and biogeochemistry can provide answers, the magnitude of the scientific challenge should not be underestimated because it becomes increasingly difficult to control the fate of N in cropping systems that must sustain yield increases on the world's limited supply of productive farm land.
Slope‐cultivated land (SCL) is essential for food security and ecological protection in Southwest China's karst mountainous areas (KMA). Constructing a unified conceptual framework to study SCL's spatiotemporal evolution characteristics thoroughly and driving mechanisms can comprehensively reveal the development of regional human–land relations and sustainable land use. Therefore, this article first constructs a conceptual framework for the spatiotemporal evolution of SCL in the KMA of Southwest China and carries out a case study in Puding County, a typical karst mountainous area, based on high‐resolution remote sensing images from 2004 to 2020 and the digital elevation model (DEM), to analyze the spatiotemporal evolution characteristics of SCL in different topographic gradients and introduce the Geodetector further to explore the driving factors of SCL evolution. The results show that the SCL is evolving toward fragmentation, driven by socio‐economic factors. The active policy of the state encourages to abandon steep SCL with poor productivity in the KMA, and the abandonment of SCL in high altitude steep slope areas into woodland and grassland brings remarkable ecological benefits, while the evolution of SCL in low altitude gentle slope areas toward economic fruit forest generates significant obvious ecological‐economic win‐win benefits. The evolution of SCL in southwestern karst mountains has promoted regional ecological restoration and made an important contribution to the greening of the world by reducing land degradation (karstic rocky desertification, KRD). The present research results can provide ideas for the utilization, functional transformation, and ecologically sustainable development of similar mountainous SCL.
Soil microbiomes drive key functions in agroecosystems, determining soil fertility, crop productivity and stress tolerance. The microbiome is intricately linked with soil structure, such as aggregation and pore connectivity, because this structure regulates the flow of water, oxygen and nutrients through the system. In this Review, we summarize the key functions of soil microbiomes in agroecosystems, highlight the dependence of these functions on the structural integrity of the soil, and discuss how agricultural practices influence the link between soil structure and microbiome functioning. System-level agricultural management practices can induce structural alterations to the soil, thereby changing the microbial processes occurring at the microscale. These changes have large-scale consequences, such as soil erosion, reduced soil fertility and increased greenhouse gas emissions. Sustainable approaches such as integrated soil fertility management and integrated pest management seek to improve soil structure and enhance microbial biodiversity, but we lack a mechanistic understanding of how multifaceted decisions at the farm level shape these context-dependent small-scale processes in the long term. Future research needs to bridge the microscale and field scale to inform agricultural management decisions for building climate-smart, resource-efficient and stress-resilient agroecosystems, and to harness the soil microbiome as a nature-based solution for sustainable agriculture. Soil structure, the soil microbiome and ecosystem functioning are intimately linked. This Review describes these connections in agroecosystems and the impact of management strategies on them.
Mountain rice terrace agriculture is a critical land use practice in southern China. Analyzing the vertical structure of rice terraces systems and the coupled evolution of their human-land relationship from a mountainous stereoscopic perspective is significant to regional resource use and sustainable agricultural development. This study took the Xijiang Township and Jiabang Township in the mountainous area of Southwest China as the research object, based on the unique rice farming environment in the mountainous region, to divide the typical types of the four-element isomorphic (FEI) of the regional forest, village, river, and rice terraces from the perspective of vertical differentiation. The spatiotemporal evolution characteristics of rice terraces based on the view of the social-ecological system were explored by using the land use data of Jiabang Township from 1962 (1977 in Xijiang Township) to 2020, and methods such as mathematical statistics, sample transect analysis. The ecological risk model was also employed to analyze the spatiotemporal variation characteristics and landscape stability of ecological risk in mountain rice terraces systems. The study showed that: (1) The rice terraces showed the “forest-terraces-village-river” (F-T-V-R), “forest-village-terraces-river” (F-V-T-R), and “forest-terraces-village-terraces-river” (F-T-V-T-R), and the rice terraces in each differentiation type experienced a continuous evolutionary feature of “development-stabilization-local shrinkage and shifted.” (2) The mixed production trend of “main rice and the auxiliary dry land” in the rice terraces landscape was gradually highlighted, and the degree of landscape abandonment and fragmentation was deepened, and the “F-T-V-T-R” structure had the highest landscape stability in long-term development. (3) The ecological risks of each landscape type showed the characteristics of “increase-stabilization-decrease” in different time series evolution. (4) Although the “F-T-V-T-R” landscape types in the two areas were at a high-risk level in the long term, the long-term changes are less fluctuating, and the landscape security stability is the highest. The research results comprehensively reflected the spatiotemporal evolution characteristics of the landscape spatial pattern of rice terraces, and revealed the reflection of the FEI vertical differentiation structure on the regional social ecosystem and human-land relationship, which can help us to promote the optimal utilization of traditional rice terraces resources in the mountains and promote the sustainable development of rice agriculture.
Quantifying the influence of factors on changes in fractional vegetation cover (FVC) is critical for assessing regional environmental changes and consequent ecological protection. However, accurately identifying the factors responsible for vegetation changes remains a challenge. This study focuses on the Wumeng Mountain Area, China (WM), where the ecological environment is extremely fragile and the social economy underdeveloped. Using the enhanced vegetation index to calculate FVC, Sen's slope trend analysis, Mann–Kendall test with the trend-free prewhitening procedure, Pettitt change-point test, and Hurst exponent, we analyzed the spatiotemporal variations in vegetation from 2000 to 2019 and projected future variations. The geographical detector model was used to analyze the spatial differentiation driving mechanism of changes in vegetation cover in the WM. We observed that the spatiotemporal variation of vegetation in the WM was significant between 2000 and 2019. The areas of the WM with extremely significant growth and significant growth accounted for 32.57% (p < 0.01) and 15.28% (0.01 < p < 0.05), respectively. The mutation years of the significantly changed vegetation were concentrated between 2007 and 2011. However, 36.09% of vegetation growth exhibited strong unsustainable characteristics and based on the past 20 years, a potential decreasing trend that has great uncertainty in the future. The geographical detector model indicated that temperature and soil type were the primary driving forces for spatial differentiation of vegetation changes in the WM, with q values of 0.131 and 0.101, respectively. Interactions between climate, topography, and human activities promote vegetation growth in a nonlinear fashion
Rural ecosystem health is an effective metrics of the stable state of rural components and subsystems referring to the ability to meet the reasonable needs of human society, self-maintain and update the ecosystem. With the development of regional ecosystem assessment, the theoretical breakthrough demand to integrate ecosystem composition integrity and ecosystem services (ES) supply–demand from the perspective of coupled human and ecosystem into ecosystem health assessment is increasing, stakeholders are interested in improving some comprehensive evaluation framework to reverse inadequate understanding of focusing on the single measurement of rural natural ecosystem status and external disturbance. This study established an improved rural ecosystem health assessment framework (REH-SD) with integrating ecological integrity and ES supply–demand from the perspective of social-economy-natural complex ecosystem, which put forward a set of assessment index system combining with SDGs17 indicators, and took Chongqing as a case study to reveal quantitatively spatiotemporal heterogeneity characteristics of rural ecosystem health. The results shown that: 1) The comprehensive score of rural ecosystem health in Chongqing from 2008 to 2018 was formed into an obvious variation evolutionary rule of gentle wave first and then rising rapidly ranging from 0.618 to 0.885, which was consistent with the trend of the physical state of rural ecosystem health (PREH); 2) The rural ecosystem health of 36 districts and counties in Chongqing increased gradually from the west Chongqing and metropolitan areas to the northeast and southeast Chongqing on the whole, showing a spatial heterogeneity of central and western collapse, northeast wings high, local protrusion, and the unhealth type (33.33%) and subhealth type (27.78%) dominated throughout the study area in 2018; 3) The improved REH-SD framework could appropriately modify the traditional evaluation results according to supply and demand relationship, the serious ecological deficit in metropolitan areas aggravated dramatically the deterioration of rural ecosystem, inversely, the REH-SD was significantly affected by the PREH in northeast and southeast Chongqing. The improved REH-SD framework was verified to be advanced comparing with the traditional evaluation method, and our results could provide significant differentiated recommendations for mountain ecological environment protection and restoration project.
Systematic elucidation of the evolution trend of karst rocky desertification (KRD) is of great significance for correctly understanding its occurrence and development process, and implementing effective comprehensive control measures. Based on the existing studies, the authors explore the formation and evolutionary mechanisms and trends of KRD in the karst mountains of Southwest China based on literature induction and field investigations. The factors driving the occurrence and formation of KRD are the single livelihood of farmers in karst mountain areas (KMA), the great land pressure, the low land carrying capacity, and the fragile ecology. Under the background of low land carrying capacity, land use systems such as over-cutting, over-cultivation, and over-grazing triggered land degradation in KMA, namely KRD. With the evolution of social and economic background and the disappearance of its driving factors, the trend of KRD expansion will undergo a fundamental turning point, namely KRD transition. KRD transition is the response of the land use system to the comprehensive action of economic and social development and ecosystem, which accords with the general trend of economic and social development and ecosystem evolution. The transition of KRD evolution found in this paper reveals the change of human-land relationship in KMA in Southwest China and provides a valuable reference for rural revitalization and ecological construction.
The karst area in Yunnan-Guangxi-Guizhou region in southwest China is known for widespread rocky desertification but several studies report a greening trend since the year 2000. While the start of the greening trend seems to match with the implementation of ecological conservation projects, no statistical evidence on a relationship between vegetation greening and eco-engineering exists. Moreover, dominant factors influencing the spatial patterns of vegetation trends have rarely been investigated. Here we use six comprehensive factors representing the natural conditions and human activities of the study area, and several statistical models consistently show that eco-engineering explains large parts of the positive vegetation trends in the karst areas, while negative vegetation trends in non-karst areas of Yunnan were related with a decrease in rainfall. We further show that the interaction of eco-engineering with other factors leads to a heterogeneous pattern of different vegetation trends. Knowing and understanding these patterns is crucial when planning ecological restoration, especially in diverse landscapes like China karst and the methods can be reused in other restoration areas.
With the introduction of the concept of land use transition into China, related researches have been carried out extensively in the past two decades, which enrich the knowledge of land system science. This paper describes the development of research on land use transitions in China from the perspectives of conceptual connotations, theoretical model, research methods, and research progress and prospects. With the in-depth investigation of land use transitions, the concept and connotations of land use morphology are developed and encapsulated as two kinds, i.e., dominant morphology and recessive morphology. The dominant morphology refers to the land use structure of a certain region over a certain period of time, with features such as the quantity and spatial pattern of land use types. While the recessive morphology includes the land use features in the aspects of quality, property rights, management mode, input, output and function. Accordingly, the concept of land use transition is further developed, and the theoretical model of regional land use transitions is established. Thereafter, three innovative integrated approaches to study land use transitions are put forward, i.e., multidisciplinary research framework for recessive land use transition, transect and horizontal comparison. To date, there have been 62 Ph.D. and 166 M.S. dissertations on the topic of “land use transition” in China. During 2002–2019, the National Natural Science Foundation of China has funded 48 research programs on the theme of “land use transition”. As such, the Chinese scholars have adapted the concept derived from western literature to the situations and experiences in China.
The detection and attribution of vegetation changes is a prerequisite for vegetation restoration and management. In arid and semi-arid areas, natural and anthropogenic factors interact to influence vegetation change, making it challenging to disentangle the contributions of driving forces. Here we used NDVI as an indicator of vegetation condition and analyzed its spatial and temporal changes in the middle reaches of the Heihe River Basin from 2000 to 2015. Then we applied the Geodetector method, a robust spatial statistics approach, to quantify the effects of natural and anthropogenic factors on NDVI changes. NDVI across the study area showed a significant increasing trend from 2000 to 2015. Both natural and anthropogenic factors were identified as significant driving forces of NDVI change, and the factors, land use conversion type, mean annual precipitation and soil type, caused the greatest influence. The explanatory power of a single factor was often enhanced when it interacted with other factors. We also found that influencing factors often correlated with NDVI changes in a non-linear way. Our research highlights that the Geodetector method is an effective way to disentangle the complicated driving factors of vegetation change, and our results is useful for projecting vegetation change under future environmental change and taking measures to prevent and mitigate land degradation in drylands.
In agricultural society, the cultivation of mountainous land was a representative of intensified contradiction between human and land which resulted in water loss and soil erosion. With the rapid urbanization and industrialization in poverty-stricken mountainous areas, the labor emigration relieves this contradiction significantly, and leads to land use transition, which results in a series of natural and socio-economic changes. This research built an analysis framework of "Land use transition-driving mechanism-effects-responses" in mountainous land use transition and then put forward the further direction of mountainous land reclamation. The results indicate that: (1) The tendency change of land use morphology was the core of rural land use transition in mountainous areas. The expansion of cropland, as well as the contraction of forest land in agricultural society, has changed to the abandonment of cropland and the expansion of forest land is the main characteristic of the dominant land use morphology transition. Land marginalization and land ecological functional recovery are the main characteristics of the recessive land use morphology transition in mountainous areas. (2) Socioeconomic factors are the primary driving forces during the mountainous land use transition. Labor emigration is the direct driving forces. Meanwhile, the rising costs of farming opportunities, and the harsh living environment that lead to labor emigration are the root cause for mountainous land use transition. (3) The transition of rural land use in mountainous areas reduces the vulnerability of land ecosystem and improves its ecological security barrier function. The advantages and disadvantages of its socio-economic effects should focus on rural development of mountainous areas and the livelihood of farmers, and need to be supported by empirical and quantitative researches. (4) The transition of land use in rural areas is a benign process of natural restoration and ecological optimization. The rural land remediation in mountainous areas should conform to the law of land use transition, and the target orientation will shift from the increase of cultivated land to the synergies of ecological and environmental protection.
Within the past decades, the karst region in the Guangxi province in southwest China has been in the focus of large scale ecological restoration projects. In this study, we adapt the pressure-state-response (PSR) framework (which includes measures for human pressure, the current state of the ecosystem and the human response) and propose a remote sensing based ecosystem health (ESH) index (0–1; 250 m spatial resolution), evaluating the pressure and state of the fragile karst ecosystem. We further apply inventory data of recovery actions (restoration areas at county level resolution) as response to ongoing degradation to test the impact of ecological restoration on the ESH. Our analysis was conducted for the years 2000, 2010 and 2016, and the results showed that 73% of the study area experienced an increase in the ESH (from 2000 to 2016) which was related to the improvements in vegetation vigor, organization, resilience, ecosystem service provisioning which offset a deterioration in fragmentation and population density. From 2000 to 2016, areas of increase in ESH were slightly larger in karst than in non-karst (37.5% and 35.1%, respectively), but also larger areas of decrease in ESH were observed in karst as compared to non-karst (16% and 11%, respectively). The results further showed that the share of areas with a high ESH (greater than 0.7) had increased by ∼3% (from 67.16% to 70.21%) during the 17 years period. At county level, we found a clear relationship between increases in ESH and ecological restoration areas (r = 0.58, p = 0.004), with a high recovery rate (ratio between areas with increased ESH and restoration areas in a county) in karst than in non-karst. We conclude that restoration projects have caused a large scale transformation of farmland into forested areas (∼5500 km²), which has caused a general improvement in ecosystem parameters related to ESH.
Ecosystem services and biodiversity are critical to ensure sustainable development of agricultural activities. Based on available scientific knowledge, high shares of biodiversity are followed by more carbon sequestration, reduced soil erosion risk, improved production and food security. This review aims to detect biodiversity services in three aspects; (1) providing ecosystem services in modern agroecosystems in response to future challenges, (2) the ability of biodiversity to support agroecosystems, and (3) the agenda for future research on biodiversity. To address our research objectives, we conducted a widespread literature search to estimate new services and roles of biodiversity in modern agroecosystems. The search was set from the date of the first relevant article until the end of the year 2017. Biodiversity is measured by many indices. Many recent studies have proposed new methods and software for biodiversity assessment such as BioFTF, BAT, LaDy and Entropart. According to the present literature review, biodiversity has a pervasive role in climate change adaptation and mitigation strategies. Levels of biodiversity, such as genetic, species and ecosystem, can affect pest control in several ways such as biological control, resulting in complex multi-trophic interactions. The relationships between land use and biodiversity are fundamental in understanding the links between people and their environment. Two models have been planned to increase production in agroecosystems whilst minimizing the consequences for biodiversity: land sharing and land sparing. Studies have shown how biodiversity can be integrated into Life Cycle Assessment (LCA) on a global scale. LCA mainly introduces biodiversity as an endpoint category modeled as a loss in species richness due to the conversion and management of land in time and space. This review shows that ecological restoration of agroecosystems is generally effective and can be recommended as a way to increase biodiversity in agricultural ecosystems. The conservation, management, and sustainable use of these services require specific attention and a coherent global policy approach. In conclusion, to protect biodiversity in agroecosystems, a policy consonance and strategic support to ecosystems should be considered. This review suggests that advanced research are needed on relationships between biodiversity and genetic erosion, map of life, pest control and urban agriculture.
Agriculture is currently facing unprecedented challenges: ensuring food, fiber and energy production in the face of global change, maintaining the economic performance of farmers and preserving natural resources such as biodiversity and associated key ecosystem services for sustainable agriculture. Addressing these challenges requires innovative landscape scale farming systems that account for changing economic and environmental targets. These novel agricultural systems need to be recognized, accepted and promoted by all stakeholders, including local residents, and supported by public policies. Agroecosystems should be considered as socio-ecological systems and alternative farming systems should be based on ecological principles while taking societal needs into account. This requires an in-depth knowledge of the multiple interactions between sociological and ecological dynamics. Long Term Socio-Ecological Research platforms (LTSER) are ideal for acquiring this knowledge as they (i) are not constrained by traditional disciplinary boundaries, (ii) operate at a large spatial scale involving all stakeholders, and (iii) use systemic approaches to investigate biodiversity and ecosystem services. This study presents the socio-ecological research strategy from the LTSER "Zone Atelier Plaine & Val de Sèvre" (ZA PVS), a large study area where data has been sampled since 1994. Its global aim is to identify effective solutions for agricultural development and the conservation of biodiversity in farmlands. Three main objectives are targeted by the ZAPVS. The first objective is intensive monitoring of landscape features, the main taxa present and agricultural practices. The second objective is the experimental investigation, in real fields with local farmers, of important ecosystem functions and services, in relation to pesticide use, crop production and farming socio-economic value. The third aim is to involve stakeholders through participatory research, citizen science and the dissemination of scientific results. This paper underlines the relevance of LTSERs for addressing agricultural challenges, while acknowledging that there are some yet unsolved key challenges.
Sustainable Development Goals offer an opportunity to improve human well-being while conserving natural resources. Ecosystem services highlight human well-being benefits ecosystems, including agricultural ecosystems, provides. Whereas agricultural systems produce the majority of our food, they drive significant environmental degradation. This tension between development and environmental conservation objectives is not an immutable outcome as agricultural systems are simultaneously dependents, and providers of ecosystem services. Recognizing this duality allows integration of environmental and development objectives and leverages agricultural ecosystem services for achieving sustainability targets. We propose a framework to operationalize ecosystem services and resilience-based interventions in agricultural landscapes and call for renewed efforts to apply resilience-based approaches to landscape management challenges and for refocusing ecosystem service research on human well-being outcomes.
To alleviate the severe rocky desertification and improve the ecological degradation conditions in Southwest China, the national and local Chinese governments have implemented a series of Ecological Restoration Projects (ERPs) since the late 1990s. This study proposed a remote sensing based approach to evaluate the long-term efforts of the ERPs started in 2000. The method applies a time-series trend analysis of satellite based vegetation data corrected for climatic influences to reveal human induced vegetation changes. The improved residual method is combined with statistics on the invested project funds to derive an index, Project Effectiveness Index (PEI), measuring the project effectiveness at county scale. High effectiveness is detected in the Guangxi Province, moderate effectiveness in the Guizhou Province, and low and no effectiveness in the Yunnan Province. Successful implementations are closely related to the combined influences from climatic conditions and human management. The landforms of Peak Forest Plain and Peak Cluster Depression regions in the Guangxi Province are characterized by temperate climate with sufficient rainfall generally leading to a high effectiveness. For the karst regions of the Yunnan and Guizhou Provinces with rough terrain and lower rainfall combined with poor management practices (unsuitable species selection, low compensation rate for peasants), only low or even no effect of project implementations can be observed. However, the effectiveness distribution is not homogeneous and counties with high project effectiveness in spite of complex natural conditions were identified, while counties with negative vegetation trends despite relatively favorable conditions and high investments were also distinguished. The proposed framework is expected to be of high relevance in general monitoring of the successfulness of ecological conservation projects in relation to invested funds.
Cash crop plantation has recently become an expanding global phenomenon. Characterizing the dynamics of cash crop plantations and the corresponding determinants should provide critical references for land use policy. Using aerial photos and geographic information system, this paper investigated the trends of four types of cash crops (tea, fruit, mulberry and nursery) and their relations to other land use changes within Hangzhou region in subtropical China. Results showed that the total cash crop cultivated surface increased by 541.3. ha from 2004 to 2014. Most of the new tea and fruit plantations were established in places previously used as forest and woodland. Mulberry and nursery mainly expanded by replacing paddy, woodland and forest. By combining household survey, geospatial techniques and multilevel regression, multilevel determinants of cash cropping probability and cash crop expansion were quantified. At the parcel level, tea and fruit plantations inclined to occur on hilly land with gentle slope. Mulberry and nursery plantations were likely to be observed in flat areas with low elevation. Parcels covered by high quality soils and with convenient communications experienced greater cash cropping probability. At the household level, households constituted of female and old-aged labor or with low agricultural labor intensity demonstrated high probability of tea and mulberry plantations. Conversely, households constituted of middle-aged labor or with high agricultural labor intensity tended to grow more fruit and nursery. Besides, wealthier households were prone to establish fruit and nursery plantations but were reluctant to involve in tea and mulberry cropping. At the village level, population density was a significant determinant of cash cropping probability, but was an insignificant determinant of cash crop expansion. Greater occurrence of cash cropping was observed in villages with higher proportion of migrant labor and leasing land. Distance to county road and distance to provincial road were identified as negative determinants. Policy was evidenced to be of significant influence on cash cropping probability and cash crop expansion. We argue that a balance should be achieved between cash cropping promotion and natural resources protection in formulating the local land use policy.
Rapid urbanization in Asia puts strong pressure on densely populated agricultural land in the peri-urban zone. It has created a specific feature, namely ‘Desakota’, as a mixed urban–rural zone which has been proposed to play an important role to support urban sustainability. However, preserving agriculture during urban expansion is hampered by the lack of understanding of its character and its economic, social, and ecological roles within the urban system. This research analyzed urbanization patterns in Jabodetabek Metropolitan Area (JMA) with Indonesia’s capital Jakarta at its core, and the dynamics of peri-urban agriculture in this context. Land use change analysis, descriptive and multivariate statistical approaches of social-economic panel data, and spatial mapping and clustering of agricultural types were applied. Results showed that rapid urbanization still continues at low development densities. It has led to the large-scale loss of farmland and increased land fragmentation. Interestingly, peri-urban agriculture still persisted and was even strengthened when JMA was hit by the economic crisis. While the area of agricultural land suffered heavy losses, the overall decline was less than expected due to conversion of woodlands into farmland. The number of farmers even increased but mostly because of a steep rise in landless farmers. Moreover, many peri-urban dwellers were still involved in on-farm and off-farm activities. We distinguished 10 agricultural types. Lowland horticulture and inland aquaculture were able to adapt and even benefit from urbanization due to proximity to the nearby urban market, whereas paddy fields, food crops and livestock were mostly displaced by urbanization and moved to the non-urbanized area. These results shed new light on the dynamics of peri-urban agriculture and indicate its persistent role in the peri-urban economy as well as supporting urban resilience during an economic crisis. Therefore, peri-urban agriculture should be regarded as a vital element of a megacity. Some strategies for its protection and development are suggested.
Carbonate rocks distribute widely in China. The total area of the carbonate rocks is about 3,430,000 km(2), and the exposed area of the carbonate is approximately 13 % of China's territory. In 2003, soil loss in Yunnan, Guizhou, and Guangxi provinces reached 179,600 km(2), which is almost 40.1 % of the total area, causing rocky desertification. In this study, the erosion-creep-collapse mechanism of underground soil loss for the karst rocky desertification in Chenqi village, Puding county, Guizhou province is proposed. The mechanism occurs under the following geological environment: slope surface undulation, underlying bedrock surface fluctuation and thin and inhomogeneous soil overlying, overlying soil generation by bedrock weathering, underground karst development, and large groundwater depth and lying water table under the bottom of soils. The erosion-creep-collapse mechanism of underground soil loss in the karst slopes is explained as follows: power loss due to human cultivation activities that destroy the soil structure, hydraulic force formed by rainfall infiltration, wet-dry cycle generated by rainfall, erosion effect caused by rainfall penetration, creeping and flowing of plastic-stream soil, and collapse. The erosion-creep-collapse mechanism of underground soil loss has seven steps: disturbance of soils filled in underground karst cave by human activities, internal soil erosion and partial collapse caused by hydraulic power, internal free surface formation within the soil in the filled karst cave, internal soil creeping, soil pipe formation, soil pipe collapse, and ground surface collapse and filling. Soil loss develops slowly, and sudden transportation occurs by collapse. Soil loss can be explained by the proposed mechanism, and soil loss can be prevented by controlling soil collapse.
Over the last half century, agricultural “modernization” has transformed smallholder potato and horticultural production
systems on the once fertile slopes of the Ecuadorian Andes (Sherwood 2009). Striving to maintain outputs, farms and fields
dotted across the mountainous landscape have increasingly used external inputs (machinery, contract labour, fertilizers, and
pesticides).
The concept of land use transition highlights that land use change is non-linear and is associated with other societal and biophysical system changes. A transition in land use is not a fixed pattern, nor is it deterministic. Land use transitions can be caused by negative socio-ecological feedbacks that arise from a depletion of key resources or from socio-economic change and innovation that take place rather independently from the ecological system. Here, we explore whether the sources of land use transitions are mostly endogenous socio-ecological forces or exogenous socio-economic factors. We first review a few generic pathways of forest transition as identified in national case studies, and evaluate the varying ecological quality of expanding forests associated with these pathways. We then discuss possible explanatory frameworks of land use transitions. We use the case of the recent forest transition in Vietnam as an illustration. Socio-ecological feedbacks seem to better explain a slowing down of deforestation and stabilization of forest cover, while exogenous socio-economic factors better account for reforestation. We conclude by discussing the prospects of accelerating land use transitions in tropical forest countries.
Research and policies aimed at biodiversity conservation in agricultural ecosystems are often less successful than expected. One common assumption is that more research is needed to develop improved measures and indicators of biodiversity. The authors’ opinion is that this is only partly true and that most of the problems arise from the lack of a well-focussed approach to this subject. Based on the knowledge available in the scientific literature, a methodological framework was developed which can help researchers and policy makers to think in a better, more structured way about issues related to biodiversity conservation in a given agroecosystem. In order to frame the importance of biodiversity in agroecosystems, three main questions were addressed through literature search: (1) What does biodiversity mean in natural and agricultural ecosystems? (2) How is the concept of functionality used in relation to biodiversity? (3) Which biodiversity measures are currently used to express agriculture–biodiversity relationships?