Main Land Research Articles

China’s National Park Construction Contributes to Carbon Peaking and Neutrality Goals

The official establishment of China’s national parks marks a new stage in the construction of China’s ecological civilization system. National parks systematically protect the areas with the richest biodiversity and the most complete ecosystem processes in China. This is beneficial not only for China’s natural conservation work, but also for the world’s response to environmental issues, such as climate change. Based on remote sensing images of land use in the four periods 1990, 2000, 2010, and 2020, this study calculated the land use changes in each national park during the corresponding period. Using the Plus model LEAS module, the driving factors of land use change in the national parks were studied and explored. In addition, the study used the InVEST model carbon storage module, using remote sensing images from different periods and the corresponding carbon pools of each national park as the basic data for model operation, to obtain the carbon storage changes in each national park over the past 30 years. Based on the hotspot analysis function, the hotspot areas of carbon storage changes in the national parks in the past 30 years were determined. Consequently, based on the CARS module of the PLUS model, the carbon storage in Northeast Tiger and Leopard National Park in 2030 was estimated under different scenarios. Research suggested that, except for Sanjiangyuan National Park where grassland is the main land use type, the other four national parks are all dominated by forests, and the expansion and changes in the main land use types were due to human activities. In the past 30 years, the carbon storage in China’s national park ecosystem has mainly shown a trend of first increasing and then gradually decreasing. Based on the changes in carbon storage in the national park, restoration scenarios were simulated for the core protected and generally controlled areas of Northeast Tiger and Leopard National Park. Under the ideal scenario, the highest value of carbon storage would be achieved by 2030, which would be 7,468,250 t higher than that in 2020. The present study provides a reference for the regional management of China’s national parks and further confirms that the implementation of the national park system can enhance China’s ability to achieve carbon peaking and neutrality goals.

Soil resource, a pending regulatory debt in Chile

Soil is a non-renewable resource on a human scale and highly vulnerable to erosion due to anthropogenic management and the variable effects of climate. In Chile, the lack of a legislative concept for soil and changes in Land Use Capacity (LUCap) have constituted the main facilitating agents of soil erosion. Given the inadequacy of current land regulations, and to guide and contribute to the sustainability of the resource, this study presents a proposal for new land use legislation in Chile. We analyse the current national legislation on changes in the LUCap and compare the current land use in the Claro River sub-basin, Chile, with existing LUCap classes, identifying the legal criteria for establishing a national land use regulation, by comparing with international law from Costa Rica and Spain. We carried out a qualitative review analysis of 20 Chilean land use regulations and a quantitative, multi-temporal analysis of LUCap change in the Claro River sub-basin, using spatial analysis tools (ArcGIS 10.1 and/or QGIS 3.14) in Raster and Vector format. Legislations from Costa Rica and Spain were chosen due to similarities with Chilean environmental regulations. We observed that Chile must introduce a Framework Land Law with principles of protection and sustainability for regulating soil. Deforestation was the main land loss driver (60% of native forest loss) in the study area during the 16-year study period, as well as inadequate agricultural management practices. It is essential to unify legislation, following the example of comparative laws of Spain, with the vision of Costa Rica.

Particulate phosphorus in runoff in a Mediterranean agroforestry catchment driven by land use and rainfall characteristics

AbstractThis study examined phosphorus (P) delivery and transport in flood events in an agroforestry catchment, with cropland and forestland as the main land uses. Sediments were collected in artificial‐lawn mats (MATs) distributed in five locations across the catchment (MAT1 to MAT5) along 20 seasonal campaigns during 5 years, in which rainfall with different characteristics was recorded. The properties analyzed in the surface soils under different land uses, and in the MATs used for collecting sediments included particle size and other properties such as soil organic matter (SOM), low frequency magnetic susceptibility (χLF) and P and Ti concentrations. The rainfall characteristics of the events recorded in each campaign were analyzed and the campaigns were grouped using cluster analysis taken into account the characteristics of the sediments collected. There was a P enrichment in the sediments compared to the sediment sources. The greatest P concentration was associated to sediment rich in clay and SOM. However, the sediment showed lower χLF, which could be due to higher erosion rates from the most degraded soils. The highest P losses were recorded at the catchment outlet, where the surface occupied by croplands was higher, with P values around 1.3 × times higher than at the headwaters. The differences between monitoring campaigns were attributed to differences in precipitation patterns that influence the hydrological response. The higher P concentration in the sediment during the campaigns that accumulated higher amount of rainfall in shorter periods of time confirmed the direct influence of rainfall intensity on the P mobilization.

İzmir'de kentleşmenin neden olduğu kent ekosistemi ve yerel iklim değişikliklerinin uzun süreli KIA oluşumu açısından STG yöntemiyle değerlendirilmesi

Even if urbanization offers various opportunities to people living in todays world. It also comes with some side effects such as worsening climate conditions by creating thermal pollution due to certain urban activities, sectoral urban designs and consequent patterns in cities. In local sense, the old climatic conditions beforete the change because of urbanization in rural areas can be called natural when they are compared with new conditions deteriorated by widespread urbanization. Thus, thermal pollution changes city’s local climate over time and negatively affects city’s resilience. Here in this research, it is determined themperature related local climate variation caused by specific city activities in the city of Izmir by analysing time series thermal data distribution over the entire city over a certain period of time and for this analyse even a novel approach is introduced and suggested which is a Simulated Single Image (SSI) method based on Simulated Single Data (SSD) statistical analyze. The method uses not only trend or average values of time series data as being as usual but it uses both and also standart deviation of the data to support a single output from the time series data analyse. Thus, outputs were obtained as single images from the the LANDSAT time series data to represent where generally Urban Hot Spots (UHS) appear and Urban Heat Islands (UHI) develop in the city. Stereo representation of the study region is also used to visually examine the topographical effect on UHI distribution in the city. Izmir which is the third mostly populated city of Turkey located on the Izmir Gulf of Egean Sea is chosen as study area and the study clearly demonstrated that industrial regions and roads with large surfaces, bare lands with sparse bushes, empty or sparse grassy urban lands and more significantly the urban land parts faced to certain directions are the main urban land cover and structure types contributing UHSs to appear and UHI developments in the city.

Uncovering the effects of policies, climate, and economic development on carbon neutrality in southern Tibet, China

Partitioning the contributions of climate, economic growth, and policy to a region’s carbon flows is an important process for the Chinese government seeking to optimize their regional development policies to achieve carbon neutrality by 2060. A combination of the carbon emission analysis and human appropriation of net primary production (HANPP) framework was applied to a village in the Lhasa river valley, Tibet, to quantify the contributions of these different factors to carbon flows and neutrality. From 2010 to 2019, the average annual net sequestration of CO2 was 374.9 g CO2 m−2 a−1. Changes in climate conditions and the regional policy of Grassland Ecological Protection Subsidy and Reward increased carbon sequestrations by 409.5 and 25.7 g CO2 m−2 a−1, respectively. Socioeconomic development, policies for reducing poverty, and promotion of forage production led to the increase in CO2 emissions by 103.5, 88.8, and 4.3 g CO2 m−2 a−1, respectively. The cumulative CO2 emissions (including HANPP) caused by land use were 298.92 Tg CO2 (2479.63 g CO2 m−2; 1 Tg = 1012 g), while the cumulative CO2 emissions due to energy use were only 11.22 Tg CO2 (93.07 g CO2 m−2), equal to 3.75% of the CO2 emissions driven by land use. Livestock grazing and cropland cultivation were the two main land use factors affecting the carbon balance. We argue that unhooking economic growth from traditional nomadic animal husbandry and lifestyles through policy optimizations would highly contribute the carbon neutrality in Tibet.

Landscape Strategies for Terraced Landscapes in the European Alpine Region Using a Mixed-Method Analysis Tool

Terraced landscapes are anthropic landscapes that need continuous management. Future planning policies need to develop bottom-up approaches in order to be able to take into consideration the perspectives of decision makers (DMs) and civil society stakeholders (CSs). Using a participatory mixed-method approach, this research work identified and prioritized the strengths, weaknesses, opportunities, and threats (SWOT analysis) perceived as key factors for setting future landscape strategies. The aims were (i) to develop a methodological framework for the enhancement of the terraced landscapes using a bottom-up approach, (ii) to identify and rank the favorable and unfavorable factors affecting their management in the European Alpine Region, and (iii) to develop alternative and future landscape strategies. The methodology was applied in nine Italian and Swiss cross-border terraced landscapes. An online focus group was organized together with a decision maker from each study area in order to identify the SWOT items for their enhancement. Subsequently, a focus group for each study area was organized with civil society stakeholders. They prioritized the SWOT items based on the local context and territorial issues using a cumulative voting method. The results were normalized, and these allowed for the development of local and supralocal landscape strategies that were both common to the cross-border terraced landscapes and specific to the main land uses characterizing them.

Temporal–spatial dynamics of typical ecosystem services in the Chaobai River basin in the Beijing-Tianjin-Hebei urban megaregion

Human demand for ecosystem services dominates ecosystem changes and impacts the temporal–spatial patterns of ecosystem services and their trade- offs. In the process of urbanization, the supply service, regulation service, and cultural service of the ecosystem are difficult to improve in synergy in the city and its surrounding areas, which is tough for urban construction and development. This study took the Chaobai River basin located in the Beijing-Tianjin-Hebei urban megaregion in northern China as the research area. The temporal and spatial changes from 2000 to 2015 of three typical ecosystem services in the study area, including food production, water conservation, and recreation, were evaluated and analyzed through modeling. The ecosystem service hotspots, service-gain areas, and service-loss areas were identified based on spatial analysis. The dynamic change mechanism of ecosystem services was explored from the perspective of land use change and hotspot analysis. The results showed that (1) recreation and food production services showed an increasing trend, while water conservation showed a fluctuating increasing trend. (2) The service-gain area was significantly larger than the service-loss area. (3) The main land use change form in the study area during the study period was the regional conversion of cultivated land to forest land and construction land, which led to the increase in water conservation services and the reduction of food production services in the corresponding patches. However, this conversion did not affect the overall improvement of the three ecosystem services in the study area. (4) Ecosystem service hotspots have gradually changed from being single-service dominant to two co-leading services. The area of food production-recreation hotspots continued to increase, indicating synergy between them. The area of water conservation-recreation hotspots continued to decrease, indicating trade-offs between them. Different types of ecosystem services improve in synergy in the Beijing-Tianjin-Hebei urban megaregion in the process of urbanization through the improvement of agricultural technology and productivity and the promotion of leisure and sightseeing agriculture. This provides an example for other cities.

Assessment and prediction of carbon storage based on land use/land cover dynamics in the coastal area of Shandong Province

Changes in land use and land cover (LULC) promote regional carbon storage capacity or trigger carbon depletion, which in turn exhibited significant impact on global climate change. Understanding the impacts of LULC on changes of carbon storage in coastal areas plays a critical role in the conservation of regional ecosystems and sustainable socio-economic development. The present study acted the coastal area of Shandong Province as an example to analyze the relationship between LULC and carbon storage combined with the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) and Patch-generating Land Use Simulation (PLUS) model. We further predicted the variation of carbon storage through the change of LULC types under three scenarios in 2030. Our results showed that cropland (which decreased by 9.41%) and built-up land (which increased by 7.66%) underwent the most significant changes over the past 20 years, while forest, grassland, wetland, water and bare land underwent less changes. As the dominant land type, cropland was also the most important carbon pool with medium carbon storage. Areas with high carbon storage were distributed in the mountains and hills, where the main land types were grassland and forest. In addition, wetland located in the Yellow River Delta also stores large amounts of carbon. Accordingly, areas with low carbon storage were widely distributed in built-up land of urban metropolitan regions. We pinpointed that the carbon storage in the coastal area of Shandong Province lost 47.96×106Mg due to the increasing of built-up land and the decreasing of cropland and forest, while ecological protection measures would effectively enhance regional carbon storage. Specifically, the regional carbon storage could be increased by 6.64×106Mg when the conversion of cropland, forest and grassland into built-up land was reduced by 20% and the conversion of wetland and water into built-up land was reduced by 30% (under the ecological priority scenario (EP)). We believe the present study could be a valid reference for administrators to develop policies in more reasonable planning of land use and urban development to achieve carbon peaking and carbon neutrality (“Dual Carbon” goals).

Soil Quality Evaluation and Dominant Factor Analysis of Economic Forest in Loess Area of Northern Shaanxi

Choosing economically important trees and establishing planting patterns can improve soil quality in economic forests. To clarify the soil quality status of the main economic forest land distributed in northern Shaanxi, the research object in this study was jujube and apple economic forests, and the control was grassland. By evaluating 17 soil indicators, the minimum data set (MDS) and structural equation model (SEM) were used to analyze the soil quality status and its dominant factors under different economic forests and land preparation methods. The results showed that (1) compared with grassland, the economic forest has a certain improvement and promotion in soil’s properties, mainly in the water-holding capacity and available nutrients. Compared to the undisturbed slope, the level bench had better physical and chemical properties. (2) Six indicators were identified as the minimum data set for assessing soil quality, including the soil organic carbon, saturated water content, bulk density, alkaline nitrogen, sand, and total capillary porosity. In addition, structural equation model analysis showed that the soil organic carbon, saturated water content, alkaline nitrogen, and capillary porosity were the dominant factors affecting soil quality in the study area. (3) Jujube trees exhibited the highest soil quality and the best restoration effect, followed by apple trees, while grassland had the poorest restoration effect. The soil quality of undisturbed slopes under different land preparation methods was lower than that of the level bench land preparation. The outcomes of this study are to provide data support and a theoretical basis for improving soil quality, enhancing ecological benefits, and selecting and managing economic forest species, in the study area and similar regions in the future.

Spatial-temporal Changes of Land Use/Cover and Its Impact on Evapotranspiration in Wuwei City

In order to grasp the sustainable development path of economy and ecology in Wuwei, based on GlobeLand30 land use/cover data from 2000 to 2020, we analyzed the spatial and temporal characteristics of land use/cover changes in Wuwei through single land use dynamic attitude, comprehensive land use dynamic attitude and land use transfer matrix, and combined with meteorological data and evapotranspiration data, clarified the driving mechanism of land use/cover change and its impact on evapotranspiration. The results show that during the period 2000—2020, shrublands and woodlands in Wuwei City had the highest combined motility, indicating that both were less stable. The main land use transfer direction in Wuwei City during 2000—2020 showed the transfer of cropland to man-made surface, forest land to grassland, and bare land to cropland and man-made surface. The distribution of ET in Wuwei City has strong spatial differences, which is very consistent with the land use/cover and surface vegetation coverage in Wuwei City. Conclusion: Temperature and rainfall have relatively limited effects on land use/cover changes in Wuwei, and only have some effects on land use/cover types such as wetlands, water bodies and woodlands. The main driving forces of land use/cover changes in Wuwei are socio-economic factors, among which GDP, real estate investment and government policies have significant effects on land use/cover type changes. The change of ET in Wuwei City is affected by both climate change and land use/cover change, and from 2010 to 2020, land use/cover dominates.

Land cover modelling for tropical forest vulnerability prediction in Kalimantan, Indonesia

This study aimed to estimate the vulnerability of tropical forest in Kalimantan, Indonesia, from simulated land cover changes using the Weighted Normalised Likelihood–Markov Chain model (WNL-MC) for the period 2018–2050 under a forest conservation and a no-conservation scenario. Predictions of future vulnerability and forest change were based on land cover maps for 2010 and 2014 developed using the integration of Landsat, ALOS PALSAR, and Sentinel-1 data. The four main land cover classes in the region were oil palm and rubber plantations, native forests, and non-forested areas. The performance of the WNL–MC model was evaluated by comparing the simulated and actual land cover maps for 2018 and validating them against high-resolution images. Kappa accuracy for the simulated maps was >85%, and overall accuracy was >90%. Under the scenario of no forest conservation, native forest showed approximately 50% loss over the next 30 years, while the forest conservation scenario showed a slowing of current deforestation by 18% from 2018 to 2030 and by 5.95% from 2030 to 2050. Native forest outside forest conservation zones was most vulnerable to conversion to other land uses, particularly in lowland areas close to settlements and roads. Estimations of native forest loss, particularly under the no-conservation scenario, emphasise the need for policies to preserve and conserve remaining native forest areas.

Geosphere Profile of Tritis Cave in Gunung Kidul Yogyakarta as a Tourism Object

The purpose of this study is to describe how the geosphere profile of Tritis cave. This study is very interesting to provide scientific input to the government in developing tourism in Gunung Kidul, Yogyakarta. The study method used is descriptive qualitative method and tends to use analysis. The theoretical basis is used as a basic reference in preparing the study report to match the conditions in the field. In addition, the theoretical basis can also provide an overview of the background of the study as material for discussion. The ability to collect data is an important factor in determining the validation of the study conducted. Data collection in this case is obtained secondarily, namely through documents or literature studies.The results of the study of geospheric phenomena that occur in the Maria Tritis cave are in the form of the main land formation is Karst with specific karst caves formed during the Pleiocene to Pleistocene. The dominant vegetation is teak trees. And the type of soil found around the maria tritis cave is a mediterranean soil type.

Changes in Carbon Dioxide Balance Associated with Land Use and Land Cover in Brazilian Legal Amazon Based on Remotely Sensed Imagery

The Amazon region comprises the largest tropical forest on the planet and is responsible for absorbing huge amounts of CO2 from the atmosphere. However, changes in land use and cover have contributed to an increase in greenhouse gas emissions, especially CO2, and in endangered indigenous lands and protected areas in the region. The objective of this study was to detect changes in CO2 emissions and removals associated with land use and land cover changes in the Brazilian Legal Amazon (BLA) through the analysis of multispectral satellite images from 2009 to 2019. The Gross Primary Production (GPP) and CO2Flux variables were estimated by the MODIS sensor onboard Terra and Aqua satellite, representing carbon absorption by vegetation during the photosynthesis process. Atmospheric CO2 concentration was estimated from the GOSAT satellite. The variables GPP and CO2Flux showed the effective flux of carbon in the BLA to atmosphere, which were weakly correlated with precipitation (r = 0.191 and 0.133). The forest absorbed 211.05 TgC annually but, due to its partial conversion to other land uses, the loss of 135,922.34 km2 of forest area resulted in 5.82 TgC less carbon being absorbed. Pasture and agriculture, which comprise the main land conversions, increased by 100,340.39 km2 and absorbed 1.32 and 3.19 TgC less, and emitted close to twice more, than forest in these areas. Atmospheric CO2 concentrations increased from 2.2 to 2.8 ppm annually in BLA, with hotspots observed in the southeast Amazonia, and CO2 capture by GPP showed an increase over the years, mainly after 2013, in the north and west of the BLA. This study brings to light the carbon dynamics, by GPP and CO2Flux models, as related to the land use and land cover in one of the biggest world carbon reservoirs, the Amazon, which is also important to fulfillment of international agreements signed by Brazil to reduce greenhouse gas emissions and for biodiversity conservation and other ecosystem services in the region.

The Dilemma of Establishing a Land Bank Institution: Social Equality or Economic Growth?

Indonesia's main land management agenda is agrarian reform, consolidating and distributing land for equity and social justice. In addition to strengthening existing institutions, Indonesia established a land bank whose main task is to provide land for investment and economic purposes. For some people, the goals of land banks interfere with land management practices in Indonesia because they are at odds with the goals of agrarian reform. So the research question that needs to be answered is what are the advantages and disadvantages of land bank practices in Indonesia? This research aims to identify the advantages and disadvantages of land bank practices in Indonesia. By identifying the advantages and disadvantages of land bank practices, the output of this study is expected to provide recommendations to improve the quality of land bank policies. This is a case study research with a qualitative approach using descriptive analysis. The data source comes from the secondary data. The study results show that establishing a land bank has one of the advantages in solving land, environmental, and spatial planning problems. Meanwhile, the weakness of the practice of land banks in Indonesia is the potential for being unconstitutional and over-authorized. Thus, from the findings of weaknesses in the practice of land banks, recommendations are made for the government to clarify the functions and objectives of land banks to improve the social and economic welfare of the Indonesian people.

Biomonitoring for Watershed Protection from a Multiscale Land-Use Perspective

The types and intensification of land use in the watershed affect the living organisms in aquatic ecosystems differently; this impact will also vary according to temporal and spatial scales. Understanding these interactions is crucial in the design of biomonitoring programs to detect the effect of different pollutants in freshwater ecosystems and improve watershed management and conservation strategies. Therefore, this paper qualitatively reviews biomonitoring studies in freshwater ecosystems to evaluate the impact of different land use types on multiple scales in watersheds. The paper is organized into four sections. The first section presents biomonitoring in different freshwater systems (streams, rivers, lakes, and reservoirs). In the second section, we describe the biomonitoring characteristics of the main land use types. In the third section, we explain how spatial and temporal scales affect biomonitoring. Finally, in the fourth section, we focus on biomonitoring planning and future prediction and discuss how to design biomonitoring programs and how to use models and eDNA in biomonitoring. Our review will assist in decision-making regarding biomonitoring programs in watersheds and will guide future studies on the different bioindicators for various land use types in diverse ecosystems worldwide.

Spatiotemporal patterns and driving factors of evapotranspiration (natural and artificial) in the Ziya River Basin, China

Evapotranspiration (ET) accounts for 60%-70% of terrestrial precipitation. Accurately calculating ET has always been one of the hot issues in ecohydrological research. Watershed ET includes natural ET and artificial ET. Natural ET includes vegetation transpiration, bare land evaporation (the two called land ET) and water surface evaporation. Artificial ET mainly refers to irrigation ET, that is, ET generated by human activities. Estimating total ET is the premise of watershed ET management. In this paper, we used the Penman‒Monteith model to estimate land ET, the Dalton model to estimate water surface evaporation, and the AquaCrop model to estimate ET generated by agricultural irrigation water in the Ziya River Basin from 2005 to 2015. Based on the integrated watershed evapotranspiration model, the effects of driving factors on ET were quantitatively analysed. The results showed that the Penman‒Monteith model, Dalton model and AquaCrop model had high simulation accuracy. The total ET fluctuated between 418.4 and 452.3 mm/yr, and the annual average ET was 437.5 mm/yr. The ET of the main land use types was ranked as woodland (496.7 mm/yr) > arable land (468.9 mm/yr) > grassland (320.0 mm/yr). Spatially, the ET in mountainous areas was lower than that in plain areas. The distribution of ET in the total amount, mountainous and plain areas, woodland, grassland and arable land showed a significant Gaussian distribution. Temporally, the interannual variation was small, and the intra-annual difference was mainly caused by climate factors. The conversion of grassland and woodland into arable land had the greatest impact on the total ET. Temperature, precipitation and leaf area index had a positive impact on ET. The impact of land cover change on ET was more significant than that of climate factors. This study can provide an integrated approach for ET estimation in water resource management and land planning.

Impact of Land Use Change on the Spatial and Temporal Evolution of Ecosystem Service Values in South China Karst Areas

Resource depletion, land-use change, and population growth triggered by the industrial revolution represent serious issues shared globally that have altered the structure, processes, and functions of ecosystems and had significant impacts on human well-being and survival security. This paper assesses changes in ecosystem service values (ESVs) in karst areas based on the perspective of land-use change. Guizhou province, which is typical of the South China Karst (SCK) ecologically fragile areas, was taken as a research subject. The past, current, and future spatial-temporal evolution of karst ESVs were assessed, using equivalence factors and CA-Markov modelling methods. The results show that: (1) from 1980 to 2040, arable land, woodland, and grassland occupy the main land types in the study area; at the same time, the water and built-up areas show a steady growth trend, with dramatic land use shifts occurring in the western, middle, and northern parts. (2) The overall ESVs increased by US$ 31.12 million during the study period, showing a temporal change trend of first decreasing and then increasing; forest land, grassland, and arable land area shift are the main factors of ESVs change; soil conservation, biodiversity conservation, and gas regulation functions are enhanced and play a vital role in the single ESVs increase; ESVs show a basin-type spatial distribution pattern. (3) The sensitivity index is <1, the ESV is inelastic to the VC factor adjustment, and the results are true and valid. This paper found that using quantitative methods to predict land use change of the South China Karst can provide accurate assessment of the differences in supply and demand for natural and social ecosystem services (ES) in a region, clarifying the trade-offs and synergies of ecosystem service functions, contributing to the achievement of sustainable development, and providing a practical reference for global land landscape optimization and land resource planners.

Interpreting regional ecological security from perspective of ecological networks: a case study in Ningxia Hui Autonomous Region, China

The rapid economic development and intense human activities have seriously restricted the sustainable development of ecology and the maintenance of ecosystem services. Ecological network can effectively connect fragmented habitats and is an important way to couple landscape structure, ecological process, and function. This study proposes a multimodel coupling framework to explore the ecological security status of Ningxia Hui Autonomous Region (NHAR) under different development scenarios from the perspective of ecological networks. The conclusions are as follows: (1) From 2000 to 2030, grassland and arable land were the main land types of NHAR. Grassland is the main expansion land type under the ecological land protection (ELP) scenario, while construction land is the main expansion land type in two other scenarios. (2) The main gather and change of the ecological sources occurred in the central region, and the ecological expansion should develop from the middle to the south. (3) The average area of ecological sources under BAU and RED scenarios is smaller than that under ELP scenario, and more ecological corridors are needed to connect. (4) The centrality of the ecological sources under the BAU scenario is generally high, but the ecological sources under ELP and RED scenarios have undergone spatial migration. In addition, the urbanization trend of NHAR is different under different scenarios, and more attention should be paid to the maintenance and protection of ecological networks in typical areas. This study can provide important reference for NHAR's ecological space planning and ecological protection policy formulation.

Urban land uses shape soil microbial abundance and diversity

Soil microbial biodiversity provides many useful services in cities. However, the ecology of microbial communities in urban soils remains poorly documented, and studies are required to better predict the impact of urban land use. We characterized microbial communities (archea/bacteria and fungi) in urban soils in Dijon (Burgundy, France). Three main land uses were considered – public leisure, traffic, and urban agriculture – sub-categorized in sub-land uses according to urban indexes and management practices. Microbial biomass and diversity were determined by quantifying and high-throughput sequencing of soil DNA. Variation partitioning analysis was used to rank soil physicochemical characteristics and land uses according to their relative contribution to the variation of soil microbial communities. Urban soils in Dijon harbored high levels of microbial biomass and diversity that varied according to land uses. Microbial biomass was 1.8 times higher in public leisure and traffic sites than in urban agriculture sites. Fungal richness increased by 25 % in urban agriculture soils, and bacterial richness was lower (by 20 %) in public leisure soils. Partitioning models explained 25.7 %, 46.2 % and 75.6 % of the variance of fungal richness, bacterial richness and microbial biomass, respectively. The organic carbon content and the C/N ratio were the best predictors of microbial biomass, whereas soil bacterial diversity was mainly explained by soil texture and land use. Neither metal trace elements nor polycyclic aromatic hydrocarbons contents explained variations of microbial communities, probably due to their very low concentration in the soils. The microbial composition results highlighted that leisure sites represented a stabilized habitat favoring specialized microbial groups and microbial plant symbionts, as opposed to urban agriculture sites that stimulated opportunistic populations able to face the impact of agricultural practices. Altogether, our results provide evidence that there is scope for urban planners to drive soil microbial diversity through sustainable urban land use and associated management practices.

Geo-Tile2Vec: A Multi-Modal and Multi-Stage Embedding Framework for Urban Analytics

Cities are very complex systems. Representing urban regions are essential for exploring, understanding, and predicting properties and features of cities. The enrichment of multi-modal urban big data has provided opportunities for researchers to enhance urban region embedding. However, existing works failed to develop an integrated pipeline that fully utilizes effective and informative data sources within geographic units. In this article, we regard a geo-tile as a geographic unit and propose a multi-modal and multi-stage representation learning framework, namely Geo-Tile2Vec, for urban analytics, especially for urban region properties identification. Specifically, in the early stage, geo-tile embeddings are firstly inferred through dynamic mobility events which are combinations of point-of-interest (POI) data and trajectory data by a Word2Vec-like model and metric learning. Then, in the latter stage, we use static street-level imagery to further enrich the embedding information by metric learning. Lastly, the framework learns distributed geo-tile embeddings for the given multi-modal data. We conduct experiments on real-world urban datasets. Four downstream tasks, i.e., main POI category classification task, main land use category classification task, restaurant average price regression task, and firm number regression task, are adopted for validating the effectiveness of the proposed framework in representing geo-tiles. Our proposed framework can significantly improve the performances of all downstream tasks. In addition, we also demonstrate that geo-tiles with similar urban region properties are geometrically closer in the vector space.