Land Use Conversion Research Articles

Isoscapes of remnant and restored Hawaiian montane forests reveal differences in biological nitrogen fixation and carbon inputs.

Deforestation and subsequent land-use conversion has altered ecosystems and led to negative effects on biodiversity. To ameliorate these effects, nitrogen-fixing (N2-fixing) trees are frequently used in the reforestation of degraded landscapes, especially in the tropics; however, their influence on ecosystem properties such as nitrogen (N) availability and carbon (C) stocks are understudied. Here, we use a 30-y old reforestation site of outplanted native N2-fixing trees (Acacia koa) dominated by exotic grass understory, and a neighboring remnant forest dominated by A. koa canopy trees and native understory, to assess whether restoration is leading to similar N and C biogeochemical landscapes and soil and plant properties as a target remnant forest ecosystem. We measured nutrient contents and isotope values (δ15N, δ13C) in soils, A. koa, and non-N2-fixing understory plants (Rubus spp.) and generated δ15N and δ13C isoscapes of the two forests to test for (1) different levels of biological nitrogen fixation (BNF) and its contribution to non-N2-fixing understory plants, and (2) the influence of historic land conversion and more recent afforestation on plant and soil δ13C. In the plantation, A. koa densities were higher and foliar δ15N values for A. koa and Rubus spp. were lower than in the remnant forest. Foliar and soil isoscapes also showed a more homogeneous distribution of low δ15N values in the plantation and greater influence of A. koa on neighboring plants and soil, suggesting greater BNF. Foliar δ13C also indicated higher water use efficiency (WUEi) in the plantation, indicative of differences in plant-water relations or soil water status between the two forest types. Plantation soil δ13C was higher than the remnant forest, consistent with greater contributions of exotic C4-pasture grasses to soil C pools, possibly due to facilitation of non-native grasses by the dense A. koa canopy. These findings are consequential for forest restoration, as they contribute to the mounting evidence that outplanting N2-fixing trees produces different biogeochemical landscapes than those observed in reference ecosystems, thereby influencing plant-soil interactions which can influence restoration outcomes.

Assessment of fluctuations in wetland ecosystem areas resulting from anthropogenic activities in the Dong Rui commune, Quang Ninh Province, Vietnam

Wetlands are one of the most important ecosystems as habitats for many animal and plant species and are crucial for disaster mitigation, improving environmental quality, storing carbon, and responding to climate change. However, these sensitive ecosystems have been heavily affected by anthropogenic activities, including aquaculture. In this study, we used multitemporal satellite imagery integrated with a verified field survey method to map the coverage of the wetland ecosystem in the Dong Rui commune, Tien Yen district, Quang Ninh Province, Vietnam, five times for four periods from 1975 to 2022, with high accuracy (overall accuracy = 92.3%, Kappa = 0.91). The results showed that from 1975 to 2000, the area of mangrove forests declined sharply (by nearly 2,000 ha), mainly due to policies of development and conversion of land use. From 2000 to 2022, the mangrove forest area was gradually restored, while the area under aquaculture shrank. Anthropogenic impacts, especially the effects of local economic development, and conservation and developmental policies, are the main causes of continuous change in each short period. Our study demonstrates satellite imagery as an effective tool for assessing wetland ecosystem area fluctuations and assessing the extent of human impacts on this natural ecosystem. Our findings can serve as a basis for planning, conservation strategies, and sustainable development of wetland ecosystems and for improving the associated livelihoods of the communities.

Exploring the emergence and changing dynamics of a new integrated rice-crawfish farming system in China

Crop-aquaculture systems are widely adopted around the world as they can provide high protein and energy outputs per unit of land and raise farm incomes, particularly for smallholder farmers. Recently, a new crop-aquaculture system, which combines rice production with crawfish breeding (integrated rice-crawfish farming), has emerged and rapidly expanded in China. However, the spatial extent and temporal dynamics of this integrated farming system largely remain unclear, which prohibits rigorous impact assessments to support its sustainable development. Here we use time series of Landsat satellite data, for the first time, to explore the emergence and the changing dynamics of this rice-crawfish farming system for the period of 2013–2021 in five provinces (805 600 km2) of China, where 90% of the global crawfish are produced. Our analysis reveals that the total area of rice-crawfish farming in these five provinces increased steadily from 0.11 Mha in 2013 to 0.70 Mha in 2019, then sharply contracted by a third in 2020 and rebounded in 2021. Spatially, rice-crawfish system is located primarily in low-elevation plain areas with abundant water resources, where paddy rice cultivation has traditionally dominated agriculture. More concentrated rice-crawfish distribution is observed in Jianghan Plain, and regions around Dongting Lake and Poyang Lake. The spatial distribution of rice-crawfish cultivation experienced considerable expansion towards the east and north from 2013 to 2021, with the largest expansion found in Jiangsu and Anhui after 2018. At the county level, over 6% of counties experienced notable area increases of more than 60 km2 from 2017 and 2019, but 20% of counties have decreased from 2019 to 2021. Among the converted land use types, irrigated cropland is the largest contributor to rice-crawfish expansion with a contribution of 56%, followed by water bodies (25%) and rainfed cropland (13%). The spatial and temporal information provided in this study helps to understand the evolution of rice-crawfish cultivation in China and facilitates more efficient management of land resources under the rapid development of this farming system.

Agricultural input modifies trophic niche and basal energy source of a top predator across human-modified landscapes

Land-use conversion and resulting habitat fragmentation can affect the source(s) of primary productivity that fuels food webs and alter their structure in ways that leads to biodiversity loss. We investigated the effects of landscape modification on food webs in the Araguaia River floodplain in central Brazil using the top predator, and indicator species Caiman crocodilus (Crocodilia, Alligatoridae). We measured carbon (δ13C) and nitrogen (δ15N) isotope values of three tissues with different isotopic incorporation rates to evaluate spatial and temporal changes in caiman isotopic niche width with hierarchical Bayesian models that accounted for habitat use, intraspecific trait variation (sex and body size), and landscape attributes (composition and configuration). We also measured δ13C values of essential amino acids to assess if different primary producers are fueling aquatic food webs in natural and anthropogenic areas. Spatial analysis showed that caiman in agricultural areas had larger isotopic niche widths, which likely reflects some use of terrestrial resources in environments dominated by C4 plants. Patterns in δ13C values among essential amino acids were clearly different between natural and anthropogenic habitats. Overall, our findings suggest that caimans can persist in heterogeneous landscapes fueled by natural and agricultural energy sources of energy, which has implications for effectively managing such landscapes to maximize biodiversity.

Patterns, Trends, and Causes of Vegetation Change in the Three Rivers Headwaters Region

The Three Rivers Headwaters Region (TRHR), situated in the high-altitude region of the Tibetan Plateau, represents a critical ecological security barrier for both China and Southeast Asia. In addition to providing a vital freshwater supply for China, it is also one of the most biodiverse areas in the world. However, the region is characterized by a fragile and sensitive ecosystem, which makes it particularly vulnerable to environmental disturbances. Given the role of vegetation as a reliable indicator of ecosystem changes, investigating the patterns and drivers of vegetation change in the TRHR can provide valuable insights into the state and trajectory of its ecological system. To assess the spatiotemporal dynamics of vegetation changes in TRHR, this study constructed a comprehensive vegetation index (CVI) based on leaf area index (LAI), fractional vegetation cover (FVC), and net primary productivity (NPP). Trend analysis and significance testing were employed to detect and quantify the magnitude and direction of vegetation changes over the past two decades. Moreover, correlation analysis, spatial overlay, and statistical modeling techniques were applied to examine the relative contributions of climate, land use/cover changes, and slope altitude to CVI changes. The results showed the following: (1) the CVI in the TRHR showed an overall increasing trend from 2000 to 2019, with an average annual increase of 0.6%, indicating a positive development trend of vegetation, but with obvious spatial differences. (2) The vegetation in the TRHR has shown a marked increase over the past two decades, with significant increase accounting for 19% of the total area, mainly concentrated in the Yellow River Basin. Conversely, a significant decline in vegetation was observed in 3% of the total area, predominantly in the Yangtze River Basin. (3) Both temperature and precipitation had a positive impact on vegetation restoration in the TRHR, but the area affected by temperature was larger than that affected by precipitation. (4) The land-use regime had a discernible impact on vegetation increase, with the conversion of land use to ecological land promoting vegetation restoration. However, the efficacy of restoration efforts might have varied depending on natural resource endowments in certain regions. (5) With increasing altitude, vegetation conditions initially improved before eventually deteriorating. Conversely, as the slope increased, vegetation experienced an initial improvement before ultimately stabilizing. This study helps to understand the overall changes and driving mechanisms of vegetation in the TRHR and provides a scientific basis and decision-making reference for the dynamic adjustment of vegetation restoration and ecological engineering in the region in the future.

Determinants of Sustainable Land Use Change in Agricultural Utilization and Environmental Performance

This paper aims to analyze the determining factors in the use of sustainable agro-industry by implementing renewable energy and environmental management performance. The paper also aims to investigate environmental policies carried out by the local government to minimize land-use conversion of agricultural utilization to non-agricultural functions. This study uses a data driven empirical approach in examining agro-industrial utilization in land-use conversion in Boyolali, Indonesia. The nature of the study was by employing sociology of law to analyze policy aspects in social interactions in environmental performance and sustainability ideas in land-use coversion cases. The results of the study show that the orientation of economic growth by implementing a renewable system and preserving agricultural land is the basis for regional policies to protect agricultural land. The findings also highlight spatial planning as the most important aspect in technical implementation of sustainability pratices in the cases of land-use conversion to non-agricultural functions. The findings would imply the need for optimization and control of agricultural land protection through environmentally-friendly local policies to control land-use conversion and maintain sustainable functions of land. The findings also imply to the importance of environmentally-friendly policies ranging from preparation of regulations, determination of regional spatial plans, environmental permits, and incentives in managing sustainability of environmental performance in land-use policy in local context.

The Mediating Role of Management Functions (Planning, Implementation, and Control) in Influencing the Restoration of Limoto Wetland

Purpose: The purpose of this study was to analyze the gap between wetland management functions and the extent of wise use and sustainable harnessing of livelihood opportunities through restoration programs. This study contributes to the comprehension of wetland management functions concerning wetland restoration through the promotion of sustainable livelihoods.
 Methodology: A cross-sectional research design was adopted. Both quantitative and qualitative data were collected using Focus Group Discussions (FGD) and interviews. FGD was conducted with five groups of beneficiaries of livelihood options. Interviews were carried out with seven key informants who were thought to be knowledgeable about the wetland restoration alternative livelihood options. These included local council chairmen from communities near the wetland, village opinion leaders, district natural resources officers, IUCN Representatives, NEMA officials, and the wetland department.
 Findings: Results showed a positive but insignificant relationship between planning function and restoration activities. Furthermore, results also indicated a negative significant relationship between implementation and restoration activities. Finally, findings revealed that there was a relationship between the control function and restoration activities. It was found out that Wetland restoration is a process that helps to transform the wetland area that has been impacted by human or natural activity into an area that can sustain native habitats. Wetlands cover 6% of global and 13% of Uganda's land cover. Over the past forty-five years, wetlands have lost 30% and 36% of land cover globally and in Uganda respectively.
 Unique Contribution to Theory, Practice, and Policy: Many wetlands, particularly those in rural Uganda are, however, getting degraded through mainly conversion of land use to agriculture, exploitation, and settlements despite the existing resource management regime. The study recommends inclusive management functions to achieve a successful wetland restoration.

Hydrological and nutrient regulation per occupation unit differ between structurally contrasting native and planted forests in the Northern Andes

Understanding ecohydrological dynamics that result from land-use conversions is fundamental in managing ecosystem services. One common forest transformation in the tropics is the establishment of monospecific plantations with exotic species for timber exploitation, replacing highly diverse natural forests. The impacts of establishing forest plantations in hydrological processes and biogeochemical dynamics have been highly controversial, with functions from structurally homogeneous plantations being sometimes assumed to be comparable to natural forests. To assess the effects of planting exotic conifer species versus natural forests on hydrological and biogeochemical functions, we measured incoming precipitation, throughfall, and stemflow. To compare between forest types, we propose the use of basal area for standardization of hydrochemical fluxes. While net precipitation was similar among forest types, the transmission of water to the forest floor per basal area unit was significantly higher in native forests. Yet, nutrient concentrations were similar among them. However, greater nutrient enrichment per unit basal area was observed for the native species. This more efficient nutrient cycling could be related to native forests being better adapted to oligotrophic soils. The re-establishment of native species rather than with exotic species can result in more efficient hydrochemical regulation, improving the capacity of these ecosystems to produce services.

Compulsory land redistribution from the perspective of the theory of price control

Philippine agrarian reform involves compulsory purchase of private farmlands. Several landowners were suspected of either using land use conversions (LUCs) to pre-empt expropriation, or choosing market-led agrarian reform (MLAR) options to retain effective control of their farmland. However, there has been no statistically-tested empirical evidence to support anecdotal claims that these were adopted by landowners to protect private property rights. Before testing whether LUCs have been used solely to avoid land redistribution, this article provides a theoretical framework that treats the reform as a price intervention policy since compensation is usually below market value. This article’s novelty lies in its application of Cheung’s theory of price control to explain how land redistribution could change the use of productive asset through LUC, or the contractual arrangement of involved parties through MLAR. Afterwards, this study employs feasible generalized least squares regression, where the effect of compulsory land redistribution on MLAR and LUC are tested to investigate the hypothesis that LUC was largely induced by agrarian reform. The results show that some LUC and MLAR were induced by the risk of expropriation, although in the case of former only when the risk of expropriation is high. Based on Cheung's theory of price control, the response choice should depend on the transaction costs associated with each of the alternatives. The theoretical framework suggests that some landowners may have preferred MLAR first before considering LUC, which is posited as one reason why the proportion of expropriation-induced LUC may not have been as high as some might like to claim.

Coupling Fuzzy Bi-Level Chance Constraint Programming and Spatial Analysis for Urban Ecological Management

In this study, a fuzzy bi-level chance constraint programming (FBCP) model is developed for urban ecological management in Xiamen, China. FBCP has advantages in balancing trade-offs between multiple decision makers and can address fuzzy and stochastic uncertainty in ecosystem management. It also can reflect the impact of different violation risk levels and emission reduction measures on system benefit, ecosystem service value, and land resource allocation. Then, the conversion of land use and its effects at small regional extent (CLUE-S) model is employed to provide the spatial allocation of future land resources under different scenarios. Results reveal that (i) carbon fixation and climate regulation are the major contributors to the ecosystem service value, with a proportion of [15.4, 15.6]% and [18.5, 18.8]%, respectively; (ii) the main environmental problem in Xiamen is the water pollution caused by the excessive discharge of commercial and residential land, with COD and NH3-N account for [68.81, 69.33]% and [67.65, 68.20]% of the total discharge of the city, respectively; (iii) the violation risk p level is the most impact factor, and the schemes with high system benefit would face greater default risk and lower ecological quality; (iv) FBCP model considers the trade-off between economic benefit and ecological quality, while the fuzzy chance constraint programming (FCP) model achieves a high system benefit at the expense of the environment. These findings help decision makers to understand the impact of parameter uncertainty and pollutant discharge policies on system benefit, and adjust land-use patterns to weigh ecological environment protection with urban economic development.

Engagement with Urban Soils Part I: Applying Maya Soil Connectivity Practices to Intergenerational Planning for Urban Sustainability

Urban soil security depends on the means and social practices that enable multiple generations to maintain and improve soil resources. Soils are pivotal to urban sustainability yet seem absent from international planning advisories for sustainable urban development. Subsuming soils under broad and unspecific categories (ecosystem, environment, land, etc.) leaves soil interests indeterminate and largely ignored in urban planning. The absence of soils in sustainable urban planning advice permits planning guidelines that cause increasing land-use conversions which seal soils. Urban patterns of sealed and distanced soils, preventing access to and direct enjoyment of soil benefits, generate disengagement from soils. Despite fierce land-use competition, urban areas offer the greatest potential for soil connectivity exactly because people concentrate there. Based on previous work we accept that everyday opportunities to encounter and directly engage with soils in Pre-Columbian lowland Maya urban life rendered soil connectivity commonplace. Here, we review how the two original routes towards soil connectivity, knowledge exchange and producer–consumer relationships, reinforced and supported regular soil engagement in Maya urban practice. We frame our interpretation of Maya cultural values and urban practices in terms of leading insights from environmental psychology on pro-environmental behaviour and stakeholder attitudes and the principles of building resilience. This allows us to recognise that Maya urban soil connectivity functions thanks to the structural involvement of the largest societal stakeholder group, while imparting soil knowledge is entangled in shared socio-cultural activities rather than a task for a minority of soil specialists. The emerging Maya model for a socially engaged soil-aware urban society combines bottom-up practices and top-down social–ecological cultural values to increase resilience, to diminish reliance on long-distance supply chains, and to maintain productive human–environment relationships over the long term. As such it becomes a primary task for urban planning advice and guidelines to enable and support a widely shared and enduring culture of soil care. Urban sustainable development may only be successful if underpinned by a broadly carried increase in soil knowledge and awareness of intergenerational soil dependency.

Vegetation Greening Enhanced the Regional Terrestrial Carbon Uptake in the Dongting Lake Basin of China

Terrestrial ecosystem carbon uptake is essential to achieving a regional carbon neutrality strategy, particularly in subtropical humid areas with dense vegetation. Due to the complex spatial and temporal heterogeneity of the carbon uptake of ecosystems, it is difficult to quantify the influence and contribution of different factors. With the aid of multisource remote sensing data, the spatiotemporal characteristics of carbon uptake and the impact of vegetation change were explored in the Dongting Lake Basin from 2001 to 2020. Based on the Conversion of Land Use and its Effects at Small regional extent (CLUE-S) model, we simulated the land use of the basin under different development scenarios in 2030. Our results showed that the basin has demonstrated a significant greening trend in the last 20 years, with a multiyear average NDVI (normalized difference vegetation index) of 0.60 and an increasing trend (y = 0.0048x − 9.069, R2 = 0.89, p < 0.01). In this context, the multiyear mean of net ecosystem productivity (NEP) was 314.95 g C·m−2·a−1 and also showed a significant increasing trend (y = 1.8915x + 295.09, R2 = 0.23, p < 0.05). Moreover, though the future carbon uptake might decrease because of the enhanced anthropogenic activities, the ecological conservation scenario might mitigate the reduction by 0.05 × 107 t. In conclusion, the greening trend enhanced the ecosystem carbon uptake in the Dongting lake basin. Considering the representativeness of the Dongting Lake Basin, the results of our study would provide useful clues for understanding the trend and pattern of terrestrial carbon uptake and for guiding the carbon neutrality strategy in the subtropical humid area.

Root litter decomposition rates and impacts of drought are regulated by ecosystem legacy

In grassland ecosystems, about two-thirds of productivity is in roots, and therefore roots constitute a major soil organic matter input. However, influences on the rate of root litter decomposition remain unresolved, especially in the context of land-use conversion and climate change. Ecosystem legacy can affect root decomposition rates via impacts on substrate chemistry and soil environments, and this may manifest in responses of decomposition to changing temperature and moisture. Here we investigate the impacts of anthropogenic legacy effects and moderate drought on root litter decomposition rates in five “Land Use History Types”: crop fields, cow pastures, remnant tallgrass prairie, and prairie restored from crop fields and pastures. We measured root losses of mass, carbon, and nitrogen over 11 months. Soil bulk density was unimportant for decomposition, but soil moisture content and temperature were relevant for decomposition rates while time since disturbance predicted decomposition initiation times. Furthermore, soil moisture and temperature dynamics alone could not explain the responses of decomposition rates to drought, which were positively correlated to time since disturbance. Our findings suggest that anthropogenic legacy impacts decomposition rates in grasslands, especially when soil moisture and temperature dynamics are substantially altered, and mediates soil community responses to drought.

Effect of the Grain‐for‐Green Program on forest fragmentation

AbstractFragmentation profoundly alters the character and pattern of forests, influencing biodiversity in the context of global climate change. Forest area density (FAD) is currently considered the most effective method for characterizing forest fragmentation. Therefore, reasonable and accurate quantification of FAD and its relationship with forest cover changes are essential for evaluating forest fragmentation in the Loess Plateau under the implementation of the Grain‐for‐Green Program (GGP). Based on land use/cover (LULC) in 1998–2022, we integrated the Random forest (RF) algorithm and the conversion of land use and its effects at small regional extent (CLUE‐S) model to derive LULC in 2030. Subsequently, we proposed a multi‐scale window threshold to evaluate forest fragmentation by constructing nonlinear models. Furthermore, we explored the relationship between FAD and forest cover changes by spatial regression models. The results are as follows: (1) in 1998–2030, the main conversion of LULC was of the cropland to broad‐leaf forests and grassland. (2) The 43 × 43 window served as the optimal multi‐scale threshold to assess forest fragmentation. (3) The GGP slowed down forest fragmentation. (4) The degree of fragmentation in broad‐leaf forests was higher than that in coniferous forests. (5) Spatial error model (SEM) was the most appropriate for establishing the spatial relationship between forest fragmentation and forest cover changes. In conclusion, since the implementation of the GGP, forest cover changes had a significant impact on forest fragmentation and its multi‐scale threshold. This research provides a basis for the reasonable configuration of land resources in the Loess Plateau and novel methods for studying forest cover changes and fragmentation.

Earthworms in the conversion of natural grasslands to agropastoral systems—a preliminary study in Vale Verde, Rio Grande do Sul, Brazil

Soils, in addition to supporting agricultural production, are the source of a wide diversity of essential ecosystem functions and services performed by invertebrate organisms. Earthworms play a key role as ecosystem engineers, but little is known about the diversity of the state of Rio Grande do Sul, Brazil, and even less concerning land-use conversion scenarios. Earthworms were sampled using the TSBF method in natural grassland (NG1) in July 2018 and subsequently converted to soybean in an agropastoral system (AP) in December 2018 and July 2019. In July 2019 a nearby natural grassland (NG2) was also sampled and considered as a reference. The earthworms were identified to family, genus and/or species, and the total number of individuals and proportion of native and exotic species were calculated and presented. A total of 583 individuals were collected and seven species were identified: three native species-Kerriona sp.7, Kerriona sp.8, Eukerria rosea; and four exotic/peregrine species-Amynthas corticis, Dichogaster bolaui, Bimastos parvus, Pontoscolex corethrurus. The two native Kerriona species are new to science and were found after the conversion of the area. The other native species (Eukerria rosea), also found after the conversion, had a high number of individuals in the last sample. The results can be related to the availability and changing of resources, due to the conversion of the land use with a high rain preceding the winter season.

Urbanization can accelerate climate change by increasing soil N2 O emission while reducing CH4 uptake.

Urban land-use change has the potential to affect local to global biogeochemical carbon (C) and nitrogen (N) cycles and associated greenhouse gas (GHG) fluxes. We conducted a meta-analysis to (1) assess the effects of urbanization-induced land-use conversion on soil nitrous oxide (N2 O) and methane (CH4 ) fluxes, (2) quantify direct N2 O emission factors (EFd ) of fertilized urban soils used, for example, as lawns or forests, and (3) identify the key drivers leading to flux changes associated with urbanization. On average, urbanization increases soil N2 O emissions by 153%, to 3.0 kg N ha-1 year-1 , while rates of soil CH4 uptake are reduced by 50%, to 2.0 kg C ha-1 year-1 . The global mean annual N2 O EFd of fertilized lawns and urban forests is 1.4%, suggesting that urban soils can be regional hotspots of N2 O emissions. On a global basis, conversion of land to urban greenspaces has increased soil N2 O emission by 0.46 Tg N2 O-N year-1 and decreased soil CH4 uptake by 0.58 Tg CH4 -C year-1 . Urbanization driven changes in soil N2 O emission and CH4 uptake are associated with changes in soil properties (bulk density, pH, total N content, and C/N ratio), increased temperature, and management practices, especially fertilizer use. Overall, our meta-analysis shows that urbanization increases soil N2 O emissions and reduces the role of soils as a sink for atmospheric CH4 . These effects can be mitigated by avoiding soil compaction, reducing fertilization of lawns, and by restoring native ecosystems in urban landscapes.

The transition characteristics and driving mechanisms of rural residential land in metropolitan areas-a case study of Tianjin, China.

Rural revitalization is the core decision for eradicating global poverty and achieving shared prosperity, and one of the most important works is to optimize and manage rural land space. A theoretical framework based on urbanization theory was built to reveal the rural residential land transition in the Tianjin metropolitan area, China from 1990 to 2020. The transition features are identified by computing the land-use conversion matrix and the rural residential land expansion index (RRLEI) and the influencing factors and mechanisms through a multiple linear regression model. The spatial distribution of rural residential land shows that it expands from the inner suburbs to the outer suburbs, then diminishes in the outer suburbs, and extends to the Binhai New Area. Low-level conflicts between rural residential land and urban construction land occurred during the rapid urbanization period, resulting in disorganized and wasteful growth. The inner suburbs have edge-expansion, dispersion, and urban encroachment patterns; the outer suburbs have edge-expansion, infilling, and dispersion patterns, with little urban encroachment; and Binhai New Area has just an edge-expansion pattern. During decelerated urbanization stage, a high-level conflict occurred between rural residential land and arable land, forestland, grassland, water, and urban construction land. Dispersion grew as urban encroachment reduced in the inner suburbs; dispersion increased while urban encroachment declined in the outer suburbs; dispersion, infilling expansion, and urban encroachment increased in the Binhai New Area. During the saturation stage of urbanization, rural residential land evolved in tandem with other forms of land use, with more efficient land use and diverse uses. The main pattern of rural residential land in a suburban region is still edge-expansion, dispersion has expanded in the Binhai New Area, and urban encroachment is the way of urban development in the inner suburbs. Economic factors and economic location strongly impact the dispersion pattern. Edge-expansion and infilling patterns are impacted by comparable variables, including geographical location, topography, population resources, and economic location. Furthermore, the amount of economic growth influences the edge-expansion pattern. It might be influenced by land policy, and the eight elements have no substantial relationship with urban occupancy. Based on resource endowment and pattern features, certain optimization techniques are given.

Optimization of Ecological Land Use Layout Based on Multimodel Coupling

Rapid urbanization is intensifying land use transitions in China by shrinking cropland and increasing land development, exacerbating land abuse, and causing environmental degradation. There are clear needs to improve land use and address these problems; however, most previous studies focused on either structural or layout optimization. In contrast, this paper proposed a method for comprehensive optimization of land use areas, layout, and structure. This involved coupling multiobjective dynamic planning (MODP), Conversion of Land Use and its Effects at Small regional extent (CLUE-S), and minimal cumulative resistance (MCR) models. In this approach, the MODP model predicted future changes that were based on areas of current land use, and the CLUE-S model simulated various future types that were based on the analysis of geographic land use and economic data. In addition, the MODP and CLUE-S models optimized the amounts and spatial distributions of land use types, respectively. The MCR model could then partition the simulation results for ecological optimization. In this paper, an illustrative application was presented that partitioned Changchun City, Jilin Province, China into construction-prohibited, restricted construction, suitable for construction, and key construction areas (which accounted for 17.41%, 30.24%, 25.32%, and 27.04%, respectively of the total area). The optimization result met expectations and provided potentially valuable reference data for spatial land use planning and ecological protection in the focal region. The proposed method to optimize the ecological layout of land use that was based on multimodel coupling considered operability and objectivity; therefore, facilitating practical applications of the results in Changchun and the presented methodology elsewhere.

Impacts of Ongoing Land-Use Change on Watershed Hydrology and Crop Production Using an Improved SWAT Model

The southern Ogallala Aquifer continues to deplete due to decades of irrigation with minimal recharge. Recently enacted regulations limiting groundwater withdrawals and the potential for farm profitability with cotton production systems indicate driving forces for increased cotton production acreage in the Northern High Plains of Texas (NHPT). This study focused on evaluating the land-use change from corn or winter wheat to cotton under irrigation and dryland conditions in the Palo Duro watershed (PDW) in the NHPT using an improved Soil and Water Assessment Tool (SWAT) model. Land-use change from irrigated corn to irrigated cotton led to reductions in average (2000–2014) annual irrigation, actual evapotranspiration (ETa), and surface runoff by 21%, 7%, and 63%, respectively. Nevertheless, the replacement of irrigated wheat with irrigated cotton caused irrigation and ETa to increase by 46% and 18%, respectively. Land-use conversion from dryland wheat to dryland cotton showed 0.1% and 15% decreases in ETa and surface runoff, respectively. More than 40% reductions in simulated cotton yields were found when the cotton planting area was moving northward to the cooler NHPT. The ongoing change in land use provided an option to lengthen the water availability of the southern Ogallala Aquifer for irrigation.

Estimating Settlement carbon stock and density using an inventory approach and quantifying their variation by land use and parcel size

A lack of very-high resolution land-cover data and in-situ carbon sampling in Settlement areas has limited the quantification of terrestrial carbon in Canadian Settlements and elsewhere. Without those data, it is difficult to quantify Settlement area terrestrial carbon for United Nations Framework Convention on Climate Change reporting within the Land Use, Land Use Change, and Forestry sector. The presented research takes a step toward filling this gap by first classifying Settlement land cover at a very-high resolution (<=80 cm, 93% overall accuracy). Then, with those data, an inventory approach is used to estimate carbon stocks based on local data, standard rulesets from the IPCC, and practice-based assumptions. Guided by FAIR principles, our approach is operationalized and available in a Jupyter Notebook for distribution, use, and extension by others. Results found that the study Settlement comprised 30% tree cover and 18% turfgrass. When analyzed by parcel size, carbon densities varied little for parcels less than 1.6 ha (3.9–4.2 kg C m-2), but then increased with larger parcels up to 6.6 Gg C m-2 for parcels > 8.1 ha. Among different land uses, industrial, commercial, and transportation had the lowest carbon densities (2.4–2.8 kg C m-2), followed by high, medium, and low-density residential (3.6, 4.0, 8.9 kg C m-2, respectively) with low-density residential almost achieving carbon densities in protected and recreation areas (10.2 kg C m-2). Our results suggest that land use is a stronger driver of carbon-storage relative to parcel size, but their combination best represents the variation in carbon-storage in low-density residential land use. Currently, only carbon change in urban trees and deforestation around urban centres is reported in Canada’s National GHG Inventory Report. The present research quantifying carbon densities provides an analysis that could inform carbon change resulting from other land-use conversions and improve deforestation estimates by better defining the final state of a land-use change.