Trends in habitat quality and habitat degradation in terrestrial protected areas.

Protected areas are typically considered a cornerstone of conservation programs and play a fundamental role in protecting natural areas and biodiversity. Human-driven land-use and land-cover (LULC) changes lead to habitat loss and biodiversity loss inside protected areas, impairing their effectiveness. However, the global dynamics of habitat quality and habitat degradation in protected areas remain unclear. We used the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model based on global annual remotely sensed data to examine the spatial and temporal trends in habitat quality and degradation in global terrestrial protected areas. Habitat quality represented the ability of habitats to provide suitable conditions for the persistence of individuals and populations, and habitat degradation represented the impacts on habitats from human-driven LULC changes in the surrounding landscape. Based on a linear mixed-effects modeling method, we also explored the relationship between habitat degradation trends and protected area characteristics, biophysical factors, and socioeconomic factors. Habitat quality declined by 0.005 (0.6%) and habitat degradation increased by 0.002 (11%) from 1992 to 2020 globally, and similar trends occurred even in remote or restrictively managed protected areas. Habitat degradation was attributed primarily to nonirrigated cropland (62%) and urbanization (27%) in 2020. Increases in elevation, gross domestic production per capita, and human population density and decreases in agricultural suitability were associated with accelerated habitat degradation. Our results suggest that human-induced LULC changes have expanded from already-exploited areas into relatively undisturbed areas, and that in wealthy countries in particular, degradation is related to rapid urbanization and increasing demand for agricultural products.

Tendencias en la calidad y degradación del hábitat en áreas protegidas terrestres Resumen Las áreas protegidas suelen considerarse la piedra angular de los programas de conservación y desempeñan un papel fundamental en la protección de los espacios naturales y la biodiversidad. Los cambios en el uso y la cobertura del suelo (CUCS) provocados por el hombre conducen a la pérdida de hábitats y de biodiversidad dentro de las áreas protegidas, lo que merma su eficacia. Sin embargo, la dinámica global de la calidad y la degradación del hábitat en las áreas protegidas sigue sin estar clara. Utilizamos el modelo de valoración integrada de servicios ambientales y compensaciones (InVEST), basado en datos anuales mundiales obtenidos por teledetección, para examinar las tendencias espaciales y temporales de la calidad y degradación del hábitat en las áreas terrestres protegidas de todo el mundo. La calidad del hábitat representó su capacidad para proporcionar condiciones adecuadas para la persistencia de individuos y poblaciones, y la degradación del hábitat representó los impactos sobre los hábitats de los cambios CUCS provocados por el hombre en el paisaje circundante. Con base en un método de modelo lineal de efectos mixtos, también exploramos la relación entre las tendencias de degradación del hábitat y las características de las áreas protegidas, los factores biofísicos y los factores socioeconómicos. La calidad del hábitat disminuyó en un 0.005 (0,6%) y la degradación del hábitat aumentó en un 0.002 (11%) entre 1992 y 2020 a nivel mundial, y se produjeron tendencias similares incluso en áreas protegidas remotas o gestionadas de forma restrictiva. La degradación del hábitat se atribuyó principalmente a las tierras de cultivo sin irrigación (62%) y a la urbanización (27%) en 2020. El aumento de la altitud, del producto interno bruto per cápita y de la densidad de población humana, así como la disminución de la idoneidad agrícola, se asociaron a una aceleración de la degradación del hábitat. Nuestros resultados sugieren que los cambios en el CUCS inducidos por el hombre se han extendido desde zonas ya explotadas a zonas relativamente inalteradas, y que, en particular en los países ricos, la degradación está relacionada con la rápida urbanización y la creciente demanda de productos agrícolas.

Spatial targeting of irrigation development and water resource management to mitigate vector-borne disease.

Scaling irrigated agriculture is a global strategy to mitigate food insecurity concerns. While expanding irrigated agriculture is critical to meeting food production demands, it is important to consider how these land use and land cover changes (LULCC) may alter the water resources of landscapes and impact the spatiotemporal epidemiology of disease. Here, a generalizable method is presented to inform irrigation development decision-making aimed at increasing crop production through irrigation while simultaneously mitigating malaria risk to surrounding communities. Changes to the spatiotemporal patterns of malaria vector (Anopheles gambiae s.s.) suitability, driven by irrigated agricultural expansion, are presented for Malawi's rainy and dry seasons. The methods presented may be applied to other geographical areas where sufficient irrigation and malaria prevalence data are available. Results show that approximately 8.60% and 1.78% of Malawi is maximally suitable for An. gambiae s.s. breeding in the rainy and dry seasons, respectively. However, the proposed LULCC from irrigated agriculture increases the maximally suitable land area in both seasons: 15.16% (rainy) and 2.17% (dry). Proposed irrigation development sites are analyzed and ranked according to their likelihood of increasing malaria risk for those closest to the schemes. Results illustrate how geospatial information on the anticipated change to the malaria landscape driven by increasing irrigated agricultural extent can assist in altering development plans, amending policies, or reassessing water resource management strategies to mitigate expected changes in malaria risk.

Assessing changes in the ecosystem service value in response to land use and land cover dynamics in Malawi.

Land use and land cover (LULC) changes are inevitable outcomes of socioeconomic changes and greatly affect ecosystem services. Our study addresses the critical gap in the existing literature by providing the first comprehensive national analysis of LULC changes and their impacts on ecosystem service values (ESVs) in Malawi. We assessed changes in ecosystem service values (ESVs) in response to LULC changes using the benefit transfer method in ArcGIS 10.6 software. Our findings revealed a significant increase in grasslands, croplands, and urban areas and a notable decline in forests, shrubs, wetlands, and water bodies. Grassland, cropland, and built-up areas expanded by 52%, 1%, and 23.2%, respectively. In contrast, permanent wetlands, barren land, and water bodies declined by 27.6%, 34.3%, and 1%, respectively. The ESV declined from US$90.87 billion in 2001 to US$85.60 billion in 2022, marking a 5.8% reduction. Provisioning services increased by 0.5% while regulating, supporting, and cultural ecosystem service functions declined by 12.2%, 3.16%, and 3.22%, respectively. The increase in provisioning services was due to the expansion of cropland. However, the loss of regulating, supporting, and cultural services was mainly due to the loss of natural ecosystems. Thus, environmental policy should prioritise the conservation and restoration of natural ecosystems to enhance the ESV of Malawi.

Availability of the current and future water resources in Equatorial Central Africa: case of the Nyong forest catchment in Cameroon.

To anticipate disasters (drought, floods, etc.) caused by environmental forcing and reduce their impacts on its fragile economy, sub-Saharan Africa needs a good knowledge of the availability of current water resources and reliable hydroclimatic forecasts. This study has an objective to quantify the availability of water resources in the Nyong basin and predict its future evolution (2024-2050). For this, the SWAT (Soil and Water Assessment Tool) model was used. The performance of this model is satisfactory in calibration (2001-2005) and validation (2006-2010), with R2, NSE, and KGE greater than 0.64. Biases of - 11.8% and - 13.9% in calibration and validation also attest to this good performance. In the investigated basin, infiltration (GW_RCH), evapotranspiration (ETP), surface runoff (SURQ), and water yield (WYLD) are greater in the East, probably due to more abundant rainfall in this part. The flows and sediment load (SED) are greater in the middle zone and in the Southwest of the basin, certainly because of the flat topography of this part, which corresponds to the valley floor. Two climate models (CCCma and REMO) predict a decline in water resources in this basin, and two others (HIRHAM5 and RCA4) are the opposite. However, based on a statistical study carried out over the historical period (2001-2005), the CCCma model seems the most reliable. It forecasts a drop in precipitation and runoff, which do not exceed - 19% and - 18%, respectively, whatever the emission scenario (RCP4.5 or RCP8.5). Climate variability (CV) is the only forcing whose impact is visible in the dynamics of current and future flows, due to the modest current (increase of + 102 km2 in builds and roads) and future (increase of + 114 km2 in builds and roads) changes observed in the evolution of land use and land cover (LULC). The results of this study could contribute to improving water resource management in the basin studied and the region.

Quantifying the policy-driven large scale vegetation restoration effects on evapotranspiration over drylands in China.

Evapotranspiration (ET) is a key variable in the water cycle and reflects the ecosystem's feedback into the climate system. However, quantitative studies on the response of ET to large-scale vegetation restoration projects and climate change are still lacking, especially in drylands. To address this deficiency, this research examined the variation in ET since the implementation of restoration projects in the drylands of China in 2000-2018, and utilized quantitative analysis methods to investigate the effects of six environmental factors, including temperature (TEM), precipitation (PRE), solar radiation (RAD), vapour pressure deficit (VPD), soil moisture (SM), and leaf area index (LAI) on ET. Furthermore, a new method was proposed to detect the ET change caused by land use and land cover change (LUCC). The results indicated that ET showed a significant increasing trend (3.54 mm yr-1) during 2000-2018, and PRE was identified as a main influential factor with an ET contribution rate of more than 50%, especially in areas with insignificant vegetation greening. Additionally, the LAI had a major positive impact on ET in the areas of significant vegetation greening, and the contribution rate was nearly 40%. Furthermore, large-scale vegetation restoration expanded the area of high-transpiration vegetation types, and the ΔET (net variable quantity of ET caused by LUCC) increased obviously especially for the changes from cropland and grassland to forest, and barren land to grassland. These findings provide a new perspective for future assessments and further decision making regarding vegetation restoration projects in drylands.

How does water diversion affect land use change and ecosystem service: A case study of Baiyangdian wetland, China.

Baiyangdian wetland is the biggest plant-dominated shallow freshwater wetland in Huabei Plain, providing a wide range of ecosystem services. In the past few decades, the water scarcity and eco-environmental problems resulted from climate changes and human activities have become more and more serious. To relieve the pressure of water scarcity and ecological degradation, the government has implemented ecological water diversion projects (EWDPs) since 1992. In this study, land use and land cover change (LUCC) caused by EWDPs over three decades was analyzed to quantitatively assess the impact of EWDPs on ecosystem services. Coefficients of ecosystem service value (ESV) calculation were improved for regional ESV evaluation. The results showed that the area of construction, farmland and water increased by 6171, 2827, 1393 ha, respectively, and the total ESV increased by 8.04 × 108 CNY primarily due to the increase of regulating service with water area expansion. Redundancy analysis and socio-economic comprehensive analysis showed that EWDPs impacted water area and ESV with threshold and time effect. When the water diversion exceeded the threshold, the EWDPs affected the ESV through influencing LUCC; otherwise, the EWDPs affected the ESV through influencing net primary productivity or social-economic benefits. However, the impact of EWDPs on ESV gradually weakened as time passed, which could not keep sustainability. With the establishment of Xiong'an New Area in China and implementation of carbon neutrality policy, rational EWDPs will become crucial to achieve goals of ecological restoration.

A global overview of studies about land management, land-use change, and climate change effects on soil organic carbon.

Major drivers of gains or losses in soil organic carbon (SOC) include land management, land-use change, and climate change. Thousands of original studies have focused on these drivers of SOC change and are now compiled in a growing number of meta-analyses. To critically assess the research efforts in this domain, we retrieved and characterized 192 meta-analyses of SOC stocks or concentrations. These meta-analyses comprise more than 13,200 original studies conducted from 1910 to 2020 in 150 countries. First, we show that, despite a growing number of studies over time, the geographical coverage of studies is limited. For example, the effect of land management, land-use change, and climate change on SOC has been only occasionally studied in North and Central Africa, and in the Middle East and Central Asia. Second, the meta-analyses investigated a limited number of land management practices, mostly mineral fertilization, organic amendments, and tillage. Third, the meta-analyses demonstrated relatively low quality and transparency. Lastly, we discuss the mismatch between the increasing number of studies and the need for more local, reusable, and diversified knowledge on how to preserve high SOC stocks or restore depleted SOC stocks.

Madagascar's fire regimes challenge global assumptions about landscape degradation.

Narratives of landscape degradation are often linked to unsustainable fire use by local communities. Madagascar is a case in point: the island is considered globally exceptional, with its remarkable endemic biodiversity viewed as threatened by unsustainable anthropogenic fire. Yet, fire regimes on Madagascar have not been empirically characterised or globally contextualised. Here, we contribute a comparative approach to determining relationships between regional fire regimes and global patterns and trends, applied to Madagascar using MODIS remote sensing data (2003-2019). Rather than a global exception, we show that Madagascar's fire regimes are similar to 88% of tropical burned area with shared climate and vegetation characteristics, and can be considered a microcosm of most tropical fire regimes. From 2003-2019, landscape-scale fire declined across tropical grassy biomes (17%-44% excluding Madagascar), and on Madagascar at a relatively fast rate (36%-46%). Thus, high tree loss anomalies on the island (1.25-4.77× the tropical average) were not explained by any general expansion of landscape-scale fire in grassy biomes. Rather, tree loss anomalies centred in forests, and could not be explained by landscape-scale fire escaping from savannas into forests. Unexpectedly, the highest tree loss anomalies on Madagascar (4.77×) occurred in environments without landscape-scale fire, where the role of small-scale fires (<21 h [0.21 km2 ]) is unknown. While landscape-scale fire declined across tropical grassy biomes, trends in tropical forests reflected important differences among regions, indicating a need to better understand regional variation in the anthropogenic drivers of forest loss and fire risk. Our new understanding of Madagascar's fire regimes offers two lessons with global implications: first, landscape-scale fire is declining across tropical grassy biomes and does not explain high tree loss anomalies on Madagascar. Second, landscape-scale fire is not uniformly associated with tropical forest loss, indicating a need for socio-ecological context in framing new narratives of fire and ecosystem degradation.

Analysis of Land Use/Cover Change and Driving Forces in the Selenga River Basin.

The Selenga River basin is an important section of the Sino-Mongolian Economic Corridor. It is an important connecting piece of the Eurasian Continental Bridge and an important part of Northeast Asia. Against the background of the evolution of the geopolitical pattern since the disintegration of the Soviet Union and global warming, based on the land cover data in the Selenga River basin from 1992, 2000, 2009, and 2015, this paper describes the dynamic changes in land use in the basin. Through a logistic model, the driving factors of land cover change were revealed, and the CA-Markov model was used to predict the land cover pattern of 2027. The results showed that (1) from 1992 to 2015, the agricultural population in the Selenga River basin continued to decrease, which led to a reduction in agricultural sown area. The intensification of climate warming and drying had a significant impact on the spatial distribution of crops. Grassland expansion mostly occurred in areas with relatively abundant rainfall, low temperature, and low human activity. (2) The simulation results showed that, according to the current development trend, the construction land area of the Selenga River basin will be slightly expanded in 2027, the area of arable land and grassland will be slightly reduced, and the areas of forest, water/wetland, and bare land will remain stable. In the future, human activities in the basin will increase in the process of the construction of the China-Mongolia-Russia economic corridor. Coupled with global warming, the land/cover of the basin will be affected by both man-made and natural disturbances, and attention should be paid to the possible risk of vegetation degradation.

The impact of land use and land cover change on groundwater recharge in northwestern Bangladesh.

Groundwater recharge is affected by various anthropogenic activities, land use and land cover (LULC) change among these. The long-term temporal and seasonal changes in LULC have a substantial influence on groundwater flow dynamics. Therefore, assessment of the impacts of LULC changes on recharge is necessary for the sustainable management of groundwater resources. The objective of this study is to examine the effects of LULC changes on groundwater recharge in the northwestern part of Bangladesh. Spatially distributed monthly groundwater recharge was simulated using a semi-physically based water balance model. Long-term temporal LULC change analysis was conducted using LULC maps from 2006 to 2016, while wet and dry LULC maps were used to examine seasonal changes. The results show that the impervious built-up area has increased by 80.3%, whereas vegetated land cover has decreased by 16.4% over the study period. As a result, groundwater recharge in 2016 has decreased compared to the level seen in 2006. However, the decrease in recharge due to long-term temporal LULC changes is very small at the basin scale (2.6 mm/year), although the impact on regional level is larger (17.1 mm/year) due to urbanization. Seasonal LULC variations also affect recharge due to the higher potential for dry seasonal LULC compared to the wet seasonal LULC, a substantial difference (20.6 mm/year). The results reveal important information about the groundwater system and its response to land cover changes in northwestern Bangladesh.

Trends and predictors of wetland conversion in urbanizing environments.

Wetlands provide critical ecosystem services including flood mitigation and habitat for diverse species, but globally, many wetlands have been destroyed. In urban areas and surrounding urban-rural fringes, many lost wetlands have been indirectly replaced with stormwater management (SWM) ponds. SWM ponds are designed to manage urban stormwater and contaminants, but only provide limited ecosystem services. In our study area, historic extent of wetland loss is partially documented, while more recent losses and SWM pond creation have not been fully reported. We examine wetland loss and SWM pond creation in seven southern Ontario (Canada) municipalities from 2002 to 2010. We then apply a Markov model to project future extent of wetland losses and SWM pond creation, with and without effects of specific land use and land cover types. We find that from 2002 to 2010, 95.5 ha of wetlands were lost, with most being smaller than 2 ha in size. A total area of 111.6 ha of SWM ponds was created, but on average, created SWM ponds were smaller than lost wetlands. Our projections to 2026 suggest wetland losses of 438.1 ha and SWM pond creation of 293.8 ha. We suggest a need for more stringent wetland protection policies to conserve wetlands that still exist in growing municipalities, especially smaller wetlands. Lack of such protection will weaken provisioning of wetland-related ecosystem services, which are more critical than ever in a changing climate.

Integrating future grassland degradation risk to improve the spatial targeting efficiency of payment for ecosystem services.

Spatial targeting plays a key role in improving the efficiency of payment for ecosystem services (PES). However, the risk of grassland degradation after implementing PES increases uncertainty about the efficiency of PES. Here, we identified the spatial heterogeneity of grassland degradation risk using Future Land Use Simulation (FLUS) model, then incorporated grassland degradation risk as a criterion into PES spatial targeting using cost-benefit analysis and ranking optimization. The framework was applied to a case study of the Three-River-Source National Park, China. We found that grasslands in the study area continued to degrade between 2015 and 2025, and the area of degraded grasslands increased by 26%. Compared with spatial targeting of PES without considering grassland degradation risk, PES spatial targeting that considered grassland degradation risk was significantly different (the overlap area accounted for only 75%, 82%, and 94% of the PES area within 25%, 50%, and 75% of the total protection cost budget). When the grassland degradation risk was considered as a targeting criterion, PES efficiency increased by 154%, 116%, 124%, and 99%, respectively, within 25%, 50%, 75%, and 100% of the total protection cost budget. Our results demonstrate that considering grassland degradation risk in the spatial targeting of PES increases efficiency because it helps to target areas with greater environmental benefits.

Combined effects of multi-land use decisions and climate change on water-related ecosystem services in Northeast China.

Land use intensification and climate change have resulted in substantial changes in the provision of ecosystem services, particularly in China that experienced sharp increases in population growth and demands for goods and energy. To protect the environment and restore the degraded ecosystems, the Chinese government has implemented multiple national ecological restoration projects. Yet, the combined effects of climate change and land use and land cover change (LULCC) over large spatial scales that brace multiple land use decisions and great environmental heterogeneity remain unclear. We assessed the combined effects of LULCC and climate change on water-related ecosystem services (water provision and soil conservation services) from 1990s to 2020s in Northeast China using the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model. We found that water yield decreased by 9.78% and soil retention increased by 30.51% over the past 30 years. LULCC and climate change exerted negative effects on water yield whereas they both enhanced soil retention; LULCC interacted with climate change to have relatively small inhibitory effects on water yield and large facilitation effects on soil retention. Changes in water yield were mainly attributed to climate change, while soil retention was largely influenced by LULCC and its interaction with climate change. Our research highlights the importance of land use decisions and its interactive effects with climate change on ecosystem services in a heavily disturbed temperate region, and provides important information to inform future land management and policy making for sustaining diverse ecosystem services and ensuring human wellbeing.

Future scenarios impact on land use change and habitat quality in Lithuania.

Anticipating future land use and land cover (LULC) changes can improve our knowledge of the complexity of human-environment interactions that lead to transformations in the landscape. Therefore, it is key to understand these LULC changes under different scenarios and how they affect habitat quality (HQ) a key indicator for ecosystem services (ES) supply quality. This work aims to study the impacts of LULC changes under different scenarios: business as usual (A0), urbanisation (A1), land abandonment and afforestation (A2) and agriculture intensification (A3) in 2050. To simulate future LULC changes we applied the Cellular Automata (CA) method, and to assess HQ, the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model was used. Spatial autocorrelation was assessed with a Moran's I index and the Getis Ord* hotspot analysis. The result showed that the LULC model calibration and validation were accurate (80%). Between 1990 and 2018 there was an increase in urban areas and forest and woodlands, which was reflected in the A0 scenario in 2050. Under the A1 scenario there was an increase in the urban area (4628 ha) compared to 2018, and in the most important cities (e.g., Vilnius, Kaunas, Klaipeda) in the scenario A2 there was an increase of 375,820 ha of woodland and forest. Finally, under the scenario A3, a large growth in cropland area (884,030 ha) was identified. HQ model had a better validation using three cover density data (r2 = 0.67), than with imperviousness (r2 = 0.26). A2 scenario showed the highest HQ and A3 scenario have the lowest HQ. The land uses of 1990, 2018, and A3 scenario had a clustered distribution while A0, A1 and A2 showed a random pattern. The results can support policy-makers by assessing the impact of future LULC changes in Lithuania.

Assessment of above-ground biomass and carbon loss from a tropical dry forest in Mexico.

Primary forests in seasonally dry tropical regions have undergone intense land-use/cover change, ranging from widespread shifting agriculture to land clearing for livestock production systems, and selective logging. Despite the importance of tropical dry forests (TDF), little is known about the implications of carbon (C) emissions from deforestation in local, national, and global scales. Therefore, the main objective of this study is to quantify and understand the processes that drive major C losses of this ecosystem in Mexico. Also, we evaluated the applicability of the already published above ground biomass (AGB) maps to quantify and allocate changes in C stocks. The results suggest that biomass maps can be used to capture the patterns of AGB distribution and to identify the driving forces of C emissions. The C losses are more related to socioeconomic drivers than biophysical characteristics like topography and climate. Besides, this study shows that published current AGB maps may be used for landscape management, including conservation and restoration areas.

Critical land change information enhances the understanding of carbon balance in the United States.

Large-scale terrestrial carbon (C) estimating studies using methods such as atmospheric inversion, biogeochemical modeling, and field inventories have produced different results. The goal of this study was to integrate fine-scale processes including land use and land cover change into a large-scale ecosystem framework. We analyzed the terrestrial C budget of the conterminous United States from 1971 to 2015 at 1-km resolution using an enhanced dynamic global vegetation model and comprehensive land cover change data. Effects of atmospheric CO2 fertilization, nitrogen deposition, climate, wildland fire, harvest, and land use/land cover change (LUCC) were considered. We estimate annual C losses from cropland harvest, forest clearcut and thinning, fire, and LUCC were 436.8, 117.9, 10.5, and 10.4 TgC/year, respectively. C stored in ecosystems increased from 119,494 to 127,157 TgC between 1971 and 2015, indicating a mean annual net C sink of 170.3 TgC/year. Although ecosystem net primary production increased by approximately 12.3 TgC/year, most of it was offset by increased C loss from harvest and natural disturbance and increased ecosystem respiration related to forest aging. As a result, the strength of the overall ecosystem C sink did not increase over time. Our modeled results indicate the conterminous US C sink was about 30% smaller than previous modeling studies, but converged more closely with inventory data.

Land use and land cover change monitoring in Bandirma (Turkey) using remote sensing and geographic information systems.

There is a growing scholarly interest in monitoring and assessment of the impacts of land use and land cover changes (LULCC) on the environment. Recent technological developments and tools of geographic information systems (GIS) and remote sensing (RS) facilitate the researches on this interest. This research aims at monitoring LULCC in Bandirma, Turkey over 30 years. This research utilizes GIS and RS techniques. Landsat satellite images of the years 1987, 2003, and 2019 are used in supervised classification methods with the maximum likelihood technique. The classified images show artificial surfaces, agricultural areas, forests, wetlands, and water bodies based on the first level classes of the Coordination of Information on the Environment (CORINE) land cover legend. Accuracy assessment is performed both before and after the correction process by using ArcGIS (10.6 Edition) software. The final overall Kappa values are above 0.95 for 3 years. These images are compared by using the Land Change Modeler tool of IDRISI (Selva Edition) software. The results represent that forest areas are increased and that wetlands are decreased in both 1987-2003 and 2003-2019 periods. Agricultural lands are decreased in the later period. Comparison maps demonstrate that land change from agricultural to artificial occurs (i) around existing settlements; (ii) along transportation axes; and (iii) in the locations of large urban land uses such as industrial areas, mines, and wind energy plants. The land change trend analysis shows that change from agricultural to artificial is the largest in the middle and southeastern parts of the area neighboring the Manyas Lake Ramsar conservation site.

Largely underestimated carbon emission from land use and land cover change in the conterminous United States.

Carbon (C) emission and uptake due to land use and land cover change (LULCC) are the most uncertain term in the global carbon budget primarily due to limited LULCC data and inadequate model capability (e.g., underrepresented agricultural managements). We take the commonly used FAOSTAT-based global Land Use Harmonization data (LUH2) and a new high-resolution multisource harmonized national LULCC database (YLmap) to drive a land ecosystem model (DLEM) in the conterminous United States. We found that recent cropland abandonment and forest recovery may have been overestimated in the LUH2 data derived from national statistics, causing previously reported C emissions from land use have been underestimated due to the definition of cropland and aggregated LULCC signals at coarse resolution. This overestimation leads to a strong C sink (30.3 ± 2.5 Tg C/year) in model simulations driven by LUH2 in the United States during the 1980-2016 period, while we find a moderate C source (13.6 ± 3.5 Tg C/year) when using YLmap. This divergence implies that previous C budget analyses based on the global LUH2 dataset have underestimated C emission in the United States owing to the delineation of suitable cropland and aggregated land conversion signals at coarse resolution which YLmap overcomes. Thus, to obtain more accurate quantification of LULCC-induced C emission and better serve global C budget accounting, it is urgently needed to develop fine-scale country-specific LULCC data to characterize the details of land conversion.

Community structure dynamics and carbon stock change of rehabilitated mangrove forests in Sulawesi, Indonesia.

To date, discourse associated with the potential application of "blue carbon" within real-world carbon markets has focused on blue carbon as a mitigation strategy in the context of avoided deforestation (e.g., REDD+). Here, we report structural dynamics and carbon storage gains from mangrove sites that have undergone rehabilitation to ascertain whether reforestation can complement conservation activities and warrant project investment. Replicated sites at two locations with contrasting geomorphic conditions were selected, Tiwoho and Tanakeke on the island of Sulawesi, Indonesia. These locations are representative of high (Tiwoho, deep muds and silty substrates) and low (Tanakeke, shallow, coralline sands) productivity mangrove ecosystems. They share a similar management history of clearing and conversion for aquaculture before restorative activities were undertaken using the practice of Ecological Mangrove Rehabilitation (EMR). Species diversity and mean biomass carbon storage gains after 10 yr of regrowth from the high productivity sites of Tiwoho (49.2 ± 9.1 Mg C·ha-1 ·yr-1 ) are already almost of one-third of mean biomass stocks exhibited by mature forests (167.8 ± 30.3 Mg C·ha-1 ·yr-1 ). Tiwoho's EMR sites, on average, will have offset all biomass C that was initially lost through conversion within the next 11 yr, a finding in marked contrast to the minimal carbon gains observed on the low productivity, low diversity, coral atoll EMR sites of Tanakeke (1.1 ± 0.4 Mg C·ha-1 ·yr-1 ). These findings highlight the importance of geomorphic and biophysical site selection if the primary purpose of EMR is intended to maximize carbon sequestration gains.

Land Use Change and Climate Variation in the Three Gorges Reservoir Catchment from 2000 to 2015 Based on the Google Earth Engine.

Possible environmental change and ecosystem degradation have received increasing attention since the construction of Three Gorges Reservoir Catchment (TGRC) in China. The advanced Google Earth Engine (GEE) cloud-based platform and the large number of Geosciences and Remote Sensing datasets archived in GEE were used to analyze the land use and land cover change (LULCC) and climate variation in TGRC. GlobeLand30 data were used to evaluate the spatial land dynamics from 2000 to 2010 and Landsat 8 Operational Land Imager (OLI) images were applied for land use in 2015. The interannual variations in the Land Surface Temperature (LST) and seasonally integrated normalized difference vegetation index (SINDVI) were estimated using Moderate Resolution Imaging Spectroradiometer (MODIS) products. The climate factors including air temperature, precipitation and evapotranspiration were investigated based on the data from the Global Land Data Assimilation System (GLDAS). The results indicated that from 2000 to 2015, the cultivated land and grassland decreased by 2.05% and 6.02%, while the forest, wetland, artificial surface, shrub land and waterbody increased by 3.64%, 0.94%, 0.87%, 1.17% and 1.45%, respectively. The SINDVI increased by 3.209 in the period of 2000-2015, while the LST decreased by 0.253 °C from 2001 to 2015. The LST showed an increasing trend primarily in urbanized area, with a decreasing trend mainly in forest area. In particular, Chongqing City had the highest LST during the research period. A marked decrease in SINDVI occurred primarily in urbanized areas. Good vegetation areas were primarily located in the eastern part of the TGRC, such as Wuxi County, Wushan County, and Xingshan County. During the 2000-2015 period, the air temperature, precipitation and evapotranspiration rose by 0.0678 °C/a, 1.0844 mm/a, and 0.4105 mm/a, respectively. The climate change in the TGRC was influenced by LULCC, but the effect was limited. What is more, the climate change was affected by regional climate change in Southwest China. Marked changes in land use have occurred in the TGRC, and they have resulted in changes in the LST and SINDVI. There was a significantly negative relationship between LST and SINDVI in most parts of the TGRC, especially in expanding urban areas and growing forest areas. Our study highlighted the importance of environmental protection, particularly proper management of land use, for sustainable development in the catchment.