Natural Vegetation Types Research Articles

Crops Feed Rain to Drylands in Northwest China

AbstractAs a key region supplementing China's limited croplands, Northwest China has undergone rapid cropland expansion over the past decades to satisfy rising food demand from population growth and socio‐economic development. Although cropland expansion may overconsume local water resources in general, in Northwest China, increased precipitation and enhanced glacier melt have increased the water available for croplands. Counterintuitively, the enhanced evapotranspiration (ET) resulting from this cropland expansion could benefit remote ecologically vulnerable natural vegetation through atmospheric moisture recycling. In this study, we used a moisture tracking model to quantify contributions of croplands and cropland expansion to local precipitation and the consequent precipitation supply to natural vegetation in Northwest China. We found that the croplands contributed 27.69 billion m3/year (2.13%) of regional total precipitation and supplied 17.30 billion m3/year (2.39%) of precipitation over natural vegetation, and the cropland expansion resulted in a net increase of 80.25 million m3/year (1.07% of the total increase) in regional precipitation and 36.23 million m3/year (4.56% of the total increase) in precipitation supply for natural vegetation. Among different types of natural vegetation, grasslands received the most precipitation supply due to its vast area, followed by forests and shrublands. The more arid regions experienced not only faster rates of cropland expansion but also obtained a greater increase in regional precipitation and precipitation supply to natural vegetation. Our study quantifies the ecological impacts of cropland expansion through moisture recycling in Northwest China. This shows the complexities of water competition between agricultural development and ecological conservation in drylands and elsewhere.

Mapping of Invasive Species Acacia Decurrens in Part of Mount Merbabu National Park Using Prisma Hyperspectral Imagery

Mount Merbabu National Park (TNGMb) is a forest area in the Mount Merbabu. Management and planting changes have caused many changes to the types of plants in TNGMb. Acacia decurrens is an invasive species and its presence in TNGMb can result in a decrease in the diversity of native vegetation types. This research aims to (1) map the distribution of Acacia decurrens plants in TNGMb using PRISMA hyperspectral imagery with the Spectral Angle Mapper (SAM) and Spectral Information Divergence (SID) methods. (2) determine and test the level of accuracy of mapping Acacia decurrens plants in TNGMb using PRISMA hyperspectral imagery. Classification results were carried out using the SAM and SID methods on PRISMA images. The best A. decurrens mapping results were SAM classification at a maximum angle of 0.3 radians with PRISMA Imagery. The distribution of Acacia decurrens in the TNGMb area is in the southwest and northwest. The best accuracy test results were from mapping Acacia decurrens with PRISMA images with an accuracy test value of 56.36%.

Through the green mosaic: Different tropical vegetation types have complementary effects on parasitoid diversity and biological control in organic agroecosystems

Land use change threaten global biodiversity, impacting ecosystem services, especially in diverse tropical regions. Yet, biodiversity conservation does not guarantee ecosystem services provision, given species' variable responses to local and landscape factors. Here, we evaluate how the landscape and local resources affect parasitoid diversity and aphid biological control in a tropical organic crop. Locally, we compared parasitoid communities within the crops and on adjacent non-crop plant strips and evaluated the effect of flower resource abundance on parasitoid diversity. At the landscape scale, we analyzed the effect of natural areas and their specific vegetational types on parasitoid diversity and the scale of these effects. Finally, we evaluated the relationship between biodiversity and biological control. Non-crop plant strips had higher parasitoid species richness and abundance than the crops, but similar species composition. Flower resource abundance in the non-crop strips negatively affected parasitoid richness. Natural areas in the landscape benefited parasitoid richness at a close range (0.42 km) and reduced parasitoid abundance at a wider scale (1.75 km). Forests and savannas increased parasitoid richness and reduced abundance, while grasslands drive parasitoid abundance and may disrupt species richness. Savannah areas, where trees and grasses coexist boosted the positive effects of forests on species richness and of grasslands on abundance. Parasitoid species richness benefited biological control exclusively in communities with intermediate and high number of parasitoid species. Our findings show that natural vegetation types with different wood densities have complementary effects in parasitoid diversity in tropical agroecosystems and represent a useful baseline for development of management and zoning plans.

U-Net Convolutional Neural Network for Mapping Natural Vegetation and Forest Types from Landsat Imagery in Southeastern Australia.

Accurate and comparable annual mapping is critical to understanding changing vegetation distribution and informing land use planning and management. A U-Net convolutional neural network (CNN) model was used to map natural vegetation and forest types based on annual Landsat geomedian reflectance composite images for a 500 km × 500 km study area in southeastern Australia. The CNN was developed using 2018 imagery. Label data were a ten-class natural vegetation and forest classification (i.e., Acacia, Callitris, Casuarina, Eucalyptus, Grassland, Mangrove, Melaleuca, Plantation, Rainforest and Non-Forest) derived by combining current best-available regional-scale maps of Australian forest types, natural vegetation and land use. The best CNN generated using six Landsat geomedian bands as input produced better results than a pixel-based random forest algorithm, with higher overall accuracy (OA) and weighted mean F1 score for all vegetation classes (93 vs. 87% in both cases) and a higher Kappa score (86 vs. 74%). The trained CNN was used to generate annual vegetation maps for 2000-2019 and evaluated for an independent test area of 100 km × 100 km using statistics describing accuracy regarding the label data and temporal stability. Seventy-six percent of pixels did not change over the 20 years (2000-2019), and year-on-year results were highly correlated (94-97% OA). The accuracy of the CNN model was further verified for the study area using 3456 independent vegetation survey plots where the species of interest had ≥ 50% crown cover. The CNN showed an 81% OA compared with the plot data. The model accuracy was also higher than the label data (76%), which suggests that imperfect training data may not be a major obstacle to CNN-based mapping. Applying the CNN to other regions would help to test the spatial transferability of these techniques and whether they can support the automated production of accurate and comparable annual maps of natural vegetation and forest types required for national reporting.

Muddy irrigation ditch understanding for agriculture environmental monitoring

Understanding an irrigation ditch plays an important role in intelligent agriculture environmental monitoring, especially in field environments where large chunks of ditches are particularly covered by various types of natural unstructured soil, vegetation and weeds. However, due to the diverse and unstructured muddy ditches, understanding them remains a challenge. Traditional approaches of understanding a scene from three-dimensional (3D) point clouds or multi-sensor fusion are energy intensive and computationally complex, making them quite laborious in application on a resource-constrained system. In this study, we propose a methodology to understand irrigation ditches and reconstruct them in a 3D scene, using only a resource-constrained monocular camera, without prior training. Spatial similar textures projections are extracted and clustered. Through geometric constraints of distribution and orientation, similar texture projections are refined and their corresponding surfaces are shaped. By contours and evidence lines, the ditch bottom surfaces are represented. Thus an irrigation ditch can be understood and reconstructed in a 3D environment, which can be used in agricultural automatic control system, agricultural robots, and precise agriculture. Unlike machine learning-based algorithms, the proposed method requires no prior training nor knowledge of the camera’s internal parameters such as focal length, field angle, and aperture. Additionally, pure geometric features make the presented method robust to varying illumination and colour. The percentage of incorrectly classified pixels was compared to the ground truth. Experimental results demonstrated that the approach can successfully elucidate irrigation ditches, meeting requirements in safety monitoring in an agriculture environment.

Nature on our doorstep: How do residents perceive urban parks vs. biodiverse areas?

The role of nature in enhancing urban well-being is well-established, but perceived naturalness may not always align with scientific definitions. Our study aimed to investigate whether areas selected for nature-related activities demonstrate increased biodiversity, offer diverse experiences, and integrate both social and ecological perspectives. We aimed to bridge the gap between perceived naturalness and objective ecological richness. Integrating social and environmental parameters, we considered both objective indicators, such as the presence of rare species, and subjective perspectives. Extensive geotagged surveys among 401 working-age Warsaw residents, coupled with field analyses, and biodiversity data collected for the scale of the whole city, allowed to juxtapose human perception with tangible ecological indicators. Our results revealed that only 14% of the locations identified by respondents as natural were associated with high biological diversity. In contrast, over 30% were in areas with low biological diversity, lacking rare species. Factors like presence of natural and semi-natural vegetation types, distance from buildings, population density, presence of water, noise, and extreme temperatures were found to be significant. We distinguished four types of natural areas: close to home, open grassland, high naturalness, and forested, reflecting different preferences and alternative choices when high-quality natural areas are not nearby. Most notably, urban parks emerged as key locations for nature contact, even though objective measures of biodiversity were often low. This underscores the need for a comprehensive understanding of how urban residents interact with and value natural spaces, bridging the gap between subjective experiences and objective ecological richness within the city's green areas. Our study highlights the complex interplay between the physical properties of urban green spaces, individual perceptions, and the ecological aesthetics influencing these interactions. In particular, the concept of perceived naturalness emerges as a critical factor, often contrasting with objective, quantifiable naturalness, and necessitating a nuanced approach in urban planning and public health contexts to cater to diverse needs and preferences of city dwellers.

DAYA DUKUNG LINGKUNGAN HIDUP BERBASIS JASA EKOSISTEM PENYEDIA AIR DAN PANGAN DI KABUPATEN HULU SUNGAI UTARA

The population growth in Hulu Sungai Utara District has led to an unsustainable exploitation of natural resources, negatively impacting environmental quality. This study aims to analyze the environmental support of ecosystem services, specifically focusing on water and food provision in the region. The analytical method involves calculating indicative environmental support based on ecosystem services. It includes the classification of ecoregion characteristics (landscapes and natural vegetation types), land cover assessment, and the creation of service/performance maps using the Simple Additive Weighting method. The results indicate a predominance of high to very high categories in the ecosystem service of water provision, covering 71.77% of the total area. Similarly, the ecosystem service of food provision is characterized by moderate to very high categories, with the moderate category covering 30.13%, the high category covering 36.32%, and the very high category comprising 24.83% of the total area in Hulu Sungai Utara District. These findings provide crucial insights for policymakers and local communities to formulate informed strategies and policies for sustainable water and food resource management.

Heterogeneity in Arbuscular Mycorrhizal Fungi and Plant Communities of the Brazilian Cerrado, Transitional Areas toward the Caatinga, and the Atlantic Forest.

The Cerrado is the most diverse tropical savanna worldwide and the second-largest biome in South America. The objective of this study was to understand the heterogeneity and dynamics of arbuscular mycorrhizal fungi (AMF) in different types of natural Cerrado vegetation and areas that are transitioning to dryer savannas or tropical rainforests and to elucidate the driving factors responsible for the differences between these ecosystems. Twenty-one natural sites were investigated, including typical Cerrado forest, typical Caatinga, Atlantic Rainforest, transitions between Cerrado and Caatinga, Cerrado areas near Caatinga or rainforest, and Carrasco sites. Spores were extracted from the soils, counted, and morphologically analyzed. In total, 82 AMF species were detected. AMF species richness varied between 36 and 51, with the highest richness found in the area transitioning between Cerrado and Caatinga, followed by areas of Cerrado close to Caatinga and typical Cerrado forest. The types of Cerrado vegetation and the areas transitioning to the Caatinga shared the highest numbers of AMF species (32-38). Vegetation, along with chemical and physical soil parameters, affected the AMF communities, which may also result from seasonal rainfall patterns. The Cerrado has a great AMF diversity and is, consequently, a natural refuge for AMF. The plant and microbial communities as well as the diversity of habitats require urgent protection within the Cerrado, as it represents a key AMF hotspot.

Spatio-temporal trends of mercury levels in alluvial gold mining spoils areas monitored between rainy and dry seasons in the Peruvian Amazon

Artisanal and small-scale gold mining (ASGM) in the Amazon has degraded tropical forests and escalated mercury (Hg) pollution, affecting biodiversity, ecological processes and rural livelihoods. In the Peruvian Amazon, ASGM annually releases some 181 tons of Hg into the environment. Despite some recent advances in understanding the spatial distribution of Hg within gold mine spoils and the surrounding landscape, temporal dynamics in Hg movement are not well understood. We aimed to reveal spatio-temporal trends of soil Hg in areas degraded by ASGM.,. We analyzed soil and sediment samples during the dry and rainy seasons across 14 ha of potentially contaminated sites and natural forests, in the vicinities of the Native community of San Jacinto in Madre de Dios, Peru. Soil Hg levels of areas impacted by ASGM (0.02 ± 0.02 mg kg−1) were generally below soil environmental quality standards (6.60 mg kg−1). However, they showed high variability, mainly explained by the type of natural cover vegetation, soil organic matter (SOM), clay and sand particles. Temporal trends in Hg levels in soils between seasons differed between landscape units distinguished in the mine spoils. During the rainy season, Hg levels decreased up to 45.5% in uncovered soils, while in artificial pond sediments Hg increased by up to 961%. During the dry season, uncovered degraded soils were more prone to lose Hg than sites covered by vegetation, mainly due to higher soil temperatures and concomitantly increasing volatilization. Soils from natural forests and degraded soil covered by regenerating vegetation showed a high capacity to retain Hg mainly due to the higher plant biomass, higher SOM, and increasing concentrations of clay particles. Disturbingly, our findings suggest high Hg mobility from gold mine spoil to close by sedimentary materials, mainly in artificial ponds through alluvial deposition and pluvial lixiviation. Thus, further research is needed on monitoring, and remediation of sediments in artificial to design sustainable land use strategies.

Producing context specific land cover and land use maps of human-modified tropical forest landscapes for infectious disease applications

Satellite-based land cover mapping plays an important role in understanding changes in ecosystems and biodiversity. There are global land cover products available, however for region specific studies of drivers of infectious disease patterns, these can lack the spatial and thematic detail or accuracy required to capture key ecological processes. To overcome this, we produced our own Landsat derived 30 m maps for three districts in India's Western Ghats (Wayanad, Shivamogga and Sindhudurg). The maps locate natural vegetation types, plantation types, agricultural areas, water bodies and settlements in the landscape, all relevant to functional resource use of species involved in infectious disease dynamics. The maps represent the mode of 50 classification iterations and include a spatial measure of class stability derived from these iterations. Overall accuracies for Wayanad, Shivamogga and Sindhudurg are 94.7 % (SE 1.2 %), 88.9 % (SE 1.2 %) and 88.8 % (SE 2 %) respectively. Class classification stability was high across all three districts and the individual classes that matter for defining key interfaces between human habitation, forests, crop, and plantation cultivation, were generally well separated. A comparison with the 300 m global ESA CCI land cover map highlights lower ESA CCI class accuracies and the importance of increased spatial resolution when dealing with complex landscape mosaics. A comparison with the 30 m Global Forest Change product reveals an accurate mapping of forest loss and different dynamics between districts (i.e., Forests lost to Built-up versus Forests lost to Plantations), demonstrating an interesting complementarity between our maps and the % tree cover Global Forest Change product. When studying infectious disease responses to land use change in tropical forest ecosystems, we recommend using bespoke land cover/use classifications reflecting functional resource use by relevant vectors, reservoirs, and people. Alternatively, global products should be carefully validated with ground reference points representing locally relevant habitats.

Investigating Soil Pore Network Connectivity in Varied Vegetation Types Using X-ray Tomography

The ecological environment in southwestern China is fragile. Due to the significant preferential flow in vertical and horizontal directions and poor water conservation ability, vegetation degradation still exists under conditions of abundant rainfall. Therefore, the pore connectivity and infiltration characteristics in shallow soil under typical local vegetation need to be studied. A calculation model for the vertical connectivity of soil macropores was independently constructed, and differences in soil macropore structures and the degree of vertical connectivity in typical vegetation types (natural secondary forest, natural grassland, Yunnan pine plantation, eucalyptus plantation, cypress plantation, mulberry bushes) were investigated by CT scanning technology of undisturbed soil columns. The results showed that the vertical connectivity of large pores in the shallow soil of the region can be quantitatively described by X-ray tomography, and the total surface area and cumulative curvature of macropores in natural grassland soil were two or three times that in artificial vegetation. The concentration area of macropores in the soil of artificial forestland was closer to the surface, and the tendency of macropore preferred path decreased by 76.18% around 30 cm depth in the soil. The vertical connection of soil macropores in artificial forests was significantly lower than that of natural secondary forestlands (33.03%) and natural grasslands (36.75%). The restoration of the plantation improved surface soil pore structure, and the vertical connectivity of soil is nearly 20% less than that of natural vegetation types (natural secondary forestland, natural grassland), which reduced water outflow rate by nearly 44% and electrolyte content by nearly 14% at a depth of 30 cm. This study provided data and research directions for the study of hydrological processes in local forest vegetation and technical support for solving the problems of soil water loss and forestland water conservation in southwestern China.

Natural Vegetation Area Design in an Arid Region Based on Water Resource Carrying Capacity—Taking Minqin County as an Example

Water resource management and natural vegetation distribution status are important for the sustainable development of agricultural, ecological and socio-economic systems in arid areas, and the carrying area of vegetation is limited by the established water resources. This study proposed the concept of natural vegetation area design in arid areas based on water resource design carrying capacity and took Minqin County belonging to a typical inland arid area as an example and socio-economic water consumption, ecological water consumption and water resource utilization efficiency in the study area as the main selected factors as well as reference indicators. By calculating the water ecological footprint, water resource carrying and water resource ecological pressure index of the main natural vegetation design area in Minqin County in 2017, we analyzed and evaluated its water resource carrying status and predicted the natural vegetation areas in 2025. The results showed that there was a large gap (the increase was 13.25–9.29%) between the actual area of various types of natural vegetation in 2017 and that in 2025. The water resource utilization was more effective in various types of natural vegetation in Minqin County under the stable development model, and the water ecological deficit was approaching 0, but the utilization of forest trees other than shrubs and herbaceous plants was in an insecure state, and the water ecological deficit was less than 0. The water resource allocation schemes under the restoration model and the optimization model were safer ecological development models for natural vegetation in Minqin County, which was in a state of water-ecological surplus, and the water-ecological surplus value was greater than 0. Thus, it could be seen that coordinating the water resource supply among various types of natural vegetation in an arid area was a preferred strategy to ensure the sustainable development of regional ecology as well as an effective countermeasure to improve the water use efficiency of natural vegetation in the county to a certain extent. This study aimed to evaluate the carrying capacity of a natural vegetation area and the water pressure index under certain water supply conditions, which could provide a reasonable theoretical reference for water resource management in arid areas.

Rapid vegetation responses over the last seven decades revealed by an alpine ice core and land-cover patterns

ContextSyntheses of vegetation responses over the last century are rare for the Alps, and limited in chronological and taxonomical resolution. We propose that pollen records from glaciers can be used to fill this gap.ObjectivesOur aim is to evaluate the reliability of glacier pollen records as historical archives of biodiversity to obtain plant diversity data and landscape changes. In detail, we aim at reconstructing taxa and vegetation trends in central sector of the Italian Alps over the last century integrating pollen-inferred vegetation trends with drifts in spatially explicit land-cover.MethodsOur study area is the Lombardy region (Italy). We performed pollen analyses of Adamello glacier cores, and reconstructed trends of single taxa and main vegetation types since the 1950s. Pollen-inferred vegetation trends were calculated using pollen indicators obtained from a database of vegetation-plot observations. The reliability of these trends is evaluated by comparison with spatially explicit tendencies reconstructed with a time-series of land-cover maps.ResultsPollen records well represent the natural vegetation types as the temperate and the riverine forests, and the anthropic vegetation as crops and alien species. From the 1980s a thermophilisation took place, and warm-demanding native and alien species expanded. The contraction of cultivated land since the 1970s, and the decline of the riverine forest appear driven by socio-economic factors.ConclusionsWe conclude that pollen-inferred vegetation trends from glaciers can be used to obtain large scale biodiversity information. This is relevant also for areas where biodiversity data are scarce but needed for landscape management planning.

Assembly Processes and Biogeographical Characteristics of Soil Bacterial Sub-communities of Different Habitats in Urban Green Spaces.

The process of urbanization is one of the most important human-driven activities that reshape the natural distribution of soil microorganisms. However, it is still unclear about the effects of urbanization on the different taxonomic soil bacterial community dynamics. In this study, we collected soil samples from highly urbanized the regions of Yangtze River Delta, Beijing-Tianjin-Hebei in China, to explore the bio-geographic patterns, assembly processes, and symbiotic patterns of abundant, moderate, and rare bacterial communities. We found that the number of moderate and rare taxa species were lower than that of abundant taxa, but their α-diversity index was higher than abundant taxa. Proteobacteria, Acidobacteria, Actinobacteria, Bacterioidetes, and Chloroflexi were the dominant phylum across all three sub-communities. And the β-diversity value of rare taxa was significantly higher than those of moderate and abundant taxa. Abundant, moderate, and rare sub-communities showed a weak distance-decay relationship, and the moderate taxa had the highest turnover rate of microbial geography in the context of urbanization. Diffusion limitation was the dominant process of soil bacterial community assembly. The co-occurrence networks of abundant, moderate, and rare taxa were dominated by positive correlations. The network of moderate taxa had the highest modularity, followed by abundant taxa. The main functions of the abundant, moderate, and rare taxa were related to Chemoheterotrophy and N transformations. Redundancy analysis showed that the dispersal limitation, climate, and soil properties were the main factors dominating bio-geographic differences in soil bacterial community diversity. We conclude that human-dominated urbanization processes have generated more uncertain survival pressures on soil bacteria, which resulted in a stronger linkage but weak bio-geographic variation for soil bacteria. In the future urban planning process, we suggest that such maintenance of native vegetation and soil types should be considered to maintain the long-term stability of local microbial ecosystem functions.

Use of Geospatial Technologies to Identify the Impact of Deforestation and its Associate Event (Soil Erosion) in the North-Bilate Watershed, Southern Ethiopia

The rapid population growth in Southern Ethiopia's North-Bilate watershed, specifically in the Boyo Lake area, has resulted in widespread deforestation and soil erosion, affecting the livelihood of farmers. Thus, the current study aimed at assessing the effects of land cover change on soil erosion and agricultural land. For this purpose, 2 lands sat ETM images for the years 2000 and 2020 which have 30*30m resolution were used. The main trajectories of land use change are based on five land use classes which are farmland, built-up area, forest, bare land, water, and open area derived from the remotely sensed images. The analysis showed that Bushland and built-up areas increased with a rate of 1.2 and 2.6 ha/year between 2000 and 2020, respectively. On the contrary, woodland, farmland, and bare land had decreased by 0.2, 0.4, and 3.2 ha/year in the same study period. The NDVI value response of the study period clearly shows the highest value for vegetation cover change, as the maximum value was +0.91 in 2000 and the minimum value was -0.38 in 2020. The dramatic expansion of settlements was due to the runoff of farmland, woodland, and bare land within the allotted period due to rapid population growth and migration from the surrounding rural areas, poor land management, and illegal housing. In summary, signs of deforestation and consequent soil erosion due to population growth, agricultural expansion, forest depletion, and mismanagement are leading to reductions in vegetation cover and agricultural productivity. To minimize soil erosion, physical measures such as terracing and dams should be implemented. In addition, to preserve and increase the biodiversity of the study area, the planting of various types of native vegetation and plantation tree species should be carried out with a viable afforestation and reforestation program.

Representativeness of the types of vegetation in the management units for the conservation of wildlife (UMA) in Mexico

The method of analysis of gaps and conservation omissions (GAP) are tools to identify conservation gaps or areas ofunderrepresentation in the current reserve system. This study focused on evaluating the extent to which the management units forthe conservation of wildlife (UMA) contribute to conservation of biodiversity in Mexico. UMA in the country cover 37,000,000million ha, equivalent to 17.1% of the national territory, however, there are only geographical references for 1,761 UMA(9,803,319 ha = 5.05%) of which it was determined with the method of analysis of gaps and conservation omissions (GAP), howthese contribute to the conservation of the types of natural vegetation, of the VI series (INEGI, 2017). Other results indicate that theUMA are located, mainly, in sites with the presence of xerophilous scrubs, which constitute 46.9% (45,182,741 ha) of the country'sprimary vegetation with 10 vegetation categories. If the UMA are considered as elements equivalent to the Natural Protected Area(ANP) in the conservation of biodiversity, they would cover 9 categories of vegetation that are conservation omissions in the ANPnetwork. However, they would not include 16 categories of secondary vegetation, which are both conservation gaps in the currentANP network; which represents a conservation gap at the national level of 72,891 ha (0.17%). However, to contribute to theconservation of biodiversity, the management of both conservation instruments must be improved.

POTENSI KESESUAIAN JENIS TANAMAN PADA AREAL LAHAN PASCATAMBANG TIMAH (STUDI KASUS DI KECAMATAN SUNGAI SELAN KABUPATEN BANGKA TENGAH PROVINSI BANGKA BELITUNG)

In addition to providing benefits, mining activities can result in physical, chemical, biological and marginal changes for plant growth. Criteria of plants used for revegetation of land mines are rapidly growing in the neighborhood marginal, allowing other types of grow on the land, producing fruits that are easily spread by birds, and producing a litter easier undergoing decomposition. This research aims to know the biodiversity and natural vegetation types of suitability identification for revegetation land post-mining tin. Observation of post-mining land was carried out to identify the physical and chemical properties of the soil and the type, density, and distribution of vegetation in the observation plots. Analysis of the suitability of vegetation types with rehabilitation land refers to the criteria in Permenhut No P.4/Menhut-II/2011 with modifications. Soil texture on former tin mining land was dominated by sand, is acidic, and has low nutrients. There were 35 types of plants found, ten species of trees and three types of shrubs among them, which have the potential to be used in revegetating post-tin mining land, namely. i.e., the Acacia mangium, Syzygium buxifolium, Syzygium racemosum Blume, Schima wallichii, Trema orientalis, Eugenia sp., Alstonia angustifolia, Ficus padana, Alstonia scholaris, Vitex pinnata L, Syzygium sp, Melastoma malabthricum dan Melastoma polyanthum.

Combined Effects of Clime, Vegetation, Human-Related Land Use and Livestock on the Distribution of the Three Indigenous Species of Gazelle in Eritrea.

The status and habitat selection of the three species of gazelle indigenous to Eritrea, i.e., Nanger soemmerringii, Gazella dorcas and Eudorcas tilonura, are not well known. In this study, we analyzed the present distribution of the three species in the country in order to identify preferred habitats and assess the effect of human disturbance (land use for agricultural purposes and livestock) on species occurrence. These data represent baseline information for evidence-based strategies for conservation of the three species in Eritrea. Presence/absence data of the three species in each of the 67 administrative subregions (Sub Zoba) composing the country were collected using direct (field surveys) and indirect methods (questionnaires). For each sampling unit, we collected fifteen environmental variables, of which three are associated with climatic features, eight with vegetation structure and four with human disturbance (human-related land use and livestock). The occurrence probability of each species was modeled through Generalized Linear Models (GLM). The analyses showed that Dorcas gazelle occurred more frequently in warmer conditions and in a wide range of natural vegetation types. Heuglin's gazelle occurred in warmer regions with higher seasonality in both temperature and precipitation with a preference for closed woody and open grassland areas. In the case of Soemmerring's gazelle, the GLM with climatic variables predicted a preference for warmer conditions but with lower seasonality of temperature and precipitation. The species also seemed to prefer arid and semi-arid open vegetation. Human disturbance is the variable with the strongest, negative, effect on the species occurrence. Indeed, the occurrence probability of each species decreased with increasing livestock density and agricultural land use. Most of these gazelle occurred in unprotected areas, thus the human-related activities are undoubtedly the most important threat for the three species of gazelle in Eritrea. Therefore, the establishment of protected areas that preserve the potential optimal habitats for gazelle and reduce the impact of livestock ranching are essential to ensure a future for these gazelle in Eritrea.

Characteristics of Soil Calcium Content Distribution in Karst Dry-Hot Valley and Its Influencing Factors

Calcium is an essential macronutrient in soils and plays an important role in the structure and function of an ecosystem. In this study, we selected the Huajiang dry-hot valley region in southwest China as our research object, aiming to comprehend the soil calcium distribution characteristics of different altitudes and vegetation types in this karst dry-hot valley region. The results showed that the mean value of total soil calcium content in the karst dry-hot valley was 13.00 ± 3.28 g·kg−1, and the mean value of the proportion of exchangeable calcium content to total calcium was 50.31%. In the vertical profile, total soil and exchangeable calcium contents decreased with increasing soil depth. With increasing altitude, total soil and exchangeable calcium contents increased. Among the different vegetation types, the total and exchangeable calcium contents of crops were higher than the three natural vegetation types of forest, scrub, and grassland, and the soil calcium content of forest was the lowest. Total soil and exchangeable calcium content in the karst dry-hot valley were affected by rock exposure rate, vegetation coverage, soil thickness, soil organic matter and soil pH. In addition, the unique environmental gradient characteristics at different elevations in the dry-hot valley area may redistribute soil calcium, and the positive vegetation succession may cause a gradual decrease of soil calcium content in the area.

Biomass and carbon stocks of four vegetation types in the Llanos Orientales of Colombia (Mapiripán, Meta)

Agricultural lands occupy 38% of global land surface and are expected to grow significantly in the next years, increasing the need for more sustainable practices, as well as better informed conservation practices of natural ecosystems. Carbon stocks are important estimates for the assessment of potential emissions caused by deforestation, and therefore widely used in strategies to mitigate climate change in agroforestry systems. Although research on biomass and carbon accumulation in agricultural lands is well documented, comparisons with adjacent natural forest areas are uncommon, mainly in tropical regions. Here, we used forest inventory data and allometric models to estimate biomass and carbon stocks of natural vegetation types (gallery forest-GF, morichal-MOR, and savanna-SAV) and oil palm (Elaeis guineensis) crops in the Orinoquía bioregion, in Eastern Colombia. We found that natural forests (GF and MOR) hold 542.45 Mg ha−1 of aboveground biomass, whereas oil palm plantations store 284.87 Mg ha−1. Morichal vegetation, commonly known as peat swamp forests, accumulated the highest aboveground biomass and carbon per hectare among all vegetation types (natural and agricultural), with an estimate of 402.76 Mg ha−1. Thus, although oil palm crops are great reservoirs of biomass and carbon at the landscape level, it is the combination of natural and agricultural lands which assure highest carbon sequestration in the study area. These results highlight the importance of preserving natural areas in agricultural landscapes for climate mitigation and conservation of biodiversity, which may jointly benefit plantations sustainable development.