Grassland Cover Research Articles

Flying insect biomass is negatively associated with urban cover in surrounding landscapes

AbstractAimIn this study, we assessed the importance of local‐ to landscape‐scale effects of land cover and land use on flying insect biomass.LocationDenmark and parts of Germany.MethodsWe used rooftop‐mounted car nets in a citizen science project (“InsectMobile”) to allow for large‐scale geographic sampling of flying insects. Volunteers sampled insects along 278 five‐km routes in urban, farmland, grassland, wetland and forest landscapes in the summer of 2018. The bulk insect samples were dried overnight to obtain the sample biomass. We extracted proportional land use variables in buffers between 50 and 1,000 m along the routes and compiled them into land cover categories to examine the effect of each land cover, and specific land use types, on insect biomass.ResultsWe found a negative association between urban cover and flying insect biomass (1% increase in urban cover = 1% [95% CI: −3.0 to 0.0] decrease in biomass in Denmark, and a 3% [95% CI: −3.0 to 0.0] decrease in Germany) at a landscape scale (1,000‐m buffer). In Denmark, we also found positive effects of semi‐natural land cover types, that is protected grassland (largest at the landscape scale, 1000 m) and forests (largest at intermediate scales, 250 m). Protected grassland cover had a stronger positive effect on insect biomass than forest cover did. For farmland cover, the positive association with insect biomass was not clearly modified by any variable associated with farmland use intensity. The negative association between insect biomass and urban land cover appeared to be reduced by increased urban green space.Main conclusionsOur results show that land cover has an impact on flying insect biomass with the magnitude of this effect varying across spatial scales. However, the vast expanse of grey space in urbanized areas has a direct negative impact on flying insect biomass across all spatial scales examined.

Impact of vegetation cover on climate change for different regions in Iraq

Vegetation determines the percentage of soil covered with green vegetation. Spatial and temporal changes of vegetation occur in the same year due to plant cycle, crop harvesting, animal grazing, and plant pruning, and vegetation areas can be divided into five main types: forest, grassland, tundra, desert, and ice cover. Climate, soil, the soil's water-holding capacity, and the slope or angle of the land determine the types of plants that will grow in a particular area, As Relative humidity is the amount of moisture in the air at a given temperature compared to what the air can hold at that temperature. The air isn't able to hold onto the water vapor because it's moving so fast. To understand the expected changes in the climatic elements of the atmosphere and water, changes in the behavior of Temperature, Relative humidity, and Vegetation cover were studied. Four stations were used over Iraq extending from north to south. The reason for choosing these stations is due to the difference in climatic changes and not only that, as the geographical nature plays an important role in determining the difference of these variables from one region to another and other weather phenomena. Obtained from the European Center for Medium-range Weather Forecast, which includes average monthly and annual temperatures, dew point, and relative humidity during the period (1988-2018) for selected stations in Iraq. Several results were reached, including that the highest value of vegetation cover for four selected stations during the study period recorded in Baghdad station was more than 0.9, and the lowest value observed in Basra station was less than 0.4. The highest relative humidity value was recorded in the Mosul station where it covered 69% in the northern and central regions of the country specifically in the winter season, and 18% in the western regions of the Rutba station in the spring and autumn. And 13% in the southern regions in the summer as seen in the Basra station. We note that the maximum temperatures were recorded in the summer in July and August due to evaporation in these areas as they are of a dry or semi-arid nature, reaching 55º C and the lowest value in the Mosul station in December and January because this area enjoys green plants and forests and precipitation. When using Spearman's test, it was found that the strength of the correlation is strong between relative humidity and vegetation cover and the relationship is positive between them, in contrast to the relationship between vegetation cover and temperature, the relationship is inverse and the strength of the correlation is weak to medium range, Finally, it was found that the spring and autumn seasons are characterized by dense vegetation cover, and this period is important for plant growth due to the availability of appropriate weather and environmental conditions.

FOREST COVER CHANGES, AND COMMUNITY PERSPECTIVE ON ITS DRIVING FORCES IN SETEMA DISTRICT JIMMA ZONE, SOUTHWEST ETHIOPIA

Globally, forests are the main components of biodiversity that represent the bases of ecosystems, through the services they give and influence human well-being through supplying services, environmental and ecological regeneration, and cultural service. In the Setema district, there is a problem of forest cover change which result in loss of soil, loss of biodiversity, change of climate, constraints of fuelwood, and constraints of farm equipment. Thus, the general objective of this study was to identify forest cover changes in the setema district and the community perspective on its direct and indirect driving forces. The study was used primary data, secondary data, a two-stage sampling design, and, 384 samples of households to accomplish the objectives of the study. The study used QGIS software, Minitab software, and, Microsoft excel 2010. The result showed that between 1988 and 2018, the forest land and grassland were lost from 62104.4 ha (56.22%) to 43867ha (39.71%), and from 17416.0 ha (15.77%) to 7208ha (6.53%), respectively. Agricultural land and settlement land were increased from 25553.5ha (23.13%) to 484805.5ha (43.89%) and from 1840.33ha (1.58%) to 7562.79ha (6.85%), respectively. The overall accuracy assessments of the 1988, 1998, 2008, and 2018 period findings were 82.6%, 85.5%, 87.6%, and 91.06 %, respectively. Based on downloaded satellite image classification, and qualitative research of KII, FGD, and HHs; forest land cover, grassland cover, bushland cover, and wetland cover were decreased and agricultural land, settlement land, and bare land were increased. According to community perception, the decrease of forest land and the increase of other land use land cover were due to the proximate drivers such as fuelwood extraction, illegal wetland conversion to agricultural land, illegal timber production, agricultural expansion, extraction of wood for house construction and underlying drivers of population growth, corruption, and lack of institutional collaboration.

Determinants of bryophyte assemblages in traditionally managed grasslands of the Carpathian Mts

Questions Although bryophytes play an important role in grassland ecosystems, environmental factors that drive bryophyte assemblages were rarely studied, especially in low-intensity traditional grasslands. Therefore, using fine-scale data on bryophyte assemblages in traditionally managed secondary grasslands, we studied the relative importance of several sets of environmental drivers (related to topography, soil properties, landscape, and management) of: (i) taxonomic and functional compositions; and (ii) cover and species richness of bryophyte communities. Location Central and Eastern Europe, Carpathian Mountains, 15 sites with preserved traditional management practices distributed in Romania (six sites), Ukraine (four), Slovakia (two), Austria (one), Hungary (one) and Poland (one). Methods Fine-scale data on soil, topography, and vegetation structure as well as on bryophyte assemblages (taxonomic and functional composition, cover, species richness) were collected in 10-m2 plots. We used stratified random sampling to select six 10-m2 plots of traditionally managed grasslands in each of the 15 sites (n = 90). Climatic and landscape variables were extracted from online databases and available maps. Detailed data on present and historical land use were obtained from parcel owners. To assess the effect of drivers on bryophyte taxonomic and functional composition we applied canonical correspondence analysis (CCA) and redundancy analysis (RDA), respectively; for bryophyte species richness and bryophyte cover we used GLMMs. Forward stepwise variable selection procedure was used to find best set of drivers for each of the analyses. Results Topographic (microrelief and solar radiation) and soil-related factors (cover of stones and rocks, soil depth, moisture), as well as the cover of the herb layer and bare soil were the strongest drivers of bryophyte taxonomic composition. Among the management- and landscape-related variables only mean size of grassland parcels within 1-km2 plot surroundings and grazing by horse were included in the CCA model explaining in total 25.9% of variation in species composition. Bryophyte functional composition was explained by a similar set of variables (RDA explained 27.3% of variation in functional composition) including additionally cover of gravel and burning. Solar radiation (negative effect) and management stability (positive effect) were the strongest drivers of bryophyte cover. Management stability had the strongest effect (positive) on bryophyte species richness, followed by grassland age (negative) and microrelief (positive). Conclusions Taxonomic and functional composition of bryophyte assemblages as well as bryophyte cover in traditional grasslands were determined mainly by variables related to moisture and light availability. Management-related factors seem to be at least as equally important as abiotic factors for bryophyte species richness and cover. Our results suggest that for maintaining bryophyte-rich grasslands one should also consider stability of grassland management, that is, temporal continuity and regularity of management practices applied.

Obstacle Indicators Diagnosis and Advantage Functions Zoning Optimization Based on “Production-Living-Ecological” Functions of National Territory Space in Jilin Province

Frequent human activities have led to different types of land use conflicts which seriously restricted the multi-functional land use and the optimal allocation of resources. Optimizing the development and utilization pattern of land space, carrying out strategic layout, taking all aspects into consideration, and promoting green production and lifestyle are important measures to alleviate the contradiction between human and land and realize the harmonious coexistence between human beings and nature. Therefore, we constructed an evaluation index system of production-living-ecological (PLE) functions in Jilin Province, and analyzed the characteristics of PLE functions via evaluation models and a spatial concentration index. Obstacle degree model and normalized revealed comparative advantage index (NRCA) were used to identify regional dominant function and diagnose obstacle factors, and function zoning and optimization strategies were carried out. The results showed that the average score of ecological function was higher than production and living functions; the spatial agglomeration degree of the three functions was low and the distribution was scattered; the regional functions were affected and hindered by obstacle factors, including total book stock in public libraries, the proportion of nature reserve area, grassland coverage rate, and the proportion of industrial and mining storage land area. Jilin Province was divided into 14 types of advantage function areas and optimization strategies were put forward. The concept of functional regionalization was applied to measure regional multifunctionality at provincial scale, which enriched the theory and practice of territorial spatial pattern optimization, promoted the coordinated development of territorial space, and provided references for provincial territorial space planning and regional sustainable development.

Impact of climate on vegetation in Pindari watershed of Western Himalayas, Kumaun, India, using spatiotemporal analysis: 1972-2018.

Vegetation dynamics is an important aspect for determining climate change trends. The present study delineates to examine spatiotemporal changes of vegetation cover in Pindari valley (Kumaun Himalaya) from the 1972 to 2018 timeline. The study includes the calculation of vegetation spectral indices of normalized vegetation index (NDVI), extraction of different vegetation classes, and statistical analysis of the Mann-Kendall (MK) test on historical metrological data (especially precipitation and temperature) of the study site. For the statistical analysis of metrological data, the power data access viewer datasets have been used. The central feature classes of the study are grassland, scrubland, and forest cover. The results revealed that the region's forest cover significantly decreased by 24.74 sq. km from 1972 to 2018, increased in grassland cover by 17.84 sq. km, respectively, and a slight increase in scrubland class by 3.13 sq. km for the study period. The calculated NDVI shows significant changes over the study location; it has been noticed that the maximum values of the NDVI decreased by 0.24, and the minimum values show growth of about 0.047. The analysis indicates that climatic parameters such as precipitation and temperature are the main limiting factors affecting vegetation growth. The annual mean maximum temperature showed a decreasing trend. The estimated results show an increase in annual rainfall and annual minimum temperature, while the decreasing trend is observed in the case of maximum annual temperature. Objectives of the study are (1) spatiotemporal analysis of the vegetation cover, (2) identification of the main causes of change in the vegetation cover, and (3) statistical trend analysis of long-term metrological data. The outcome of the presented research work would be beneficial for the proper management and monitoring of the forest ecosystem.

The 30m-NDVI-Based Alpine Grassland Changes and Climate Impacts in the Three-River Headwaters Region on the Qinghai-Tibet Plateau from 1990 to 2018

The response of long-term vegetation changes and climate change has been a hot topic in recent research. Previously, a Landsat-based fusion model was developed and used to produce a dataset of normalized vegetation index (NDVI) for the Three-River Headwater region on the Qinghai-Tibet Plateau with a spatial resolution of 30 m and the time spanning the nearly 30 years from 1990 to 2018. In this study, the NDVI was applied to an analysis of the spatial and temporal changes in the alpine grassland and the impacts from climate change using the Theil-Sen Median method and linear regression. The results showed that: (1) The regional mean NDVI was 0.39 and showed a spatial pattern of decreasing from the southeast to the northwest in the recent three decades. Among the three parks, the Lancang River Park had the highest NDVI (0.43), followed by the Yellow River Park (0.38) and Yangtze River Park (0.23). (2) An upward trending was found in the NDVI time series at a rate of 0.0031 yr–1 (R2 =0.62, P < 0.01) over the whole period of 1990–2018. The increasing rate (0.00649 yr–1, R2 =0.71, P < 0.01) in the latter period of 2005–2018 was nearly 2.3 times of that (0.00284 yr–1, R2 =0.31, P < 0.01) in the previous period of 1990–2005. In the latest periods, the three parks experienced rates that were 2.3 to 63 times the corresponding values in the early period. (3) The NDVI is correlated more positively with temperature than precipitation. The impacts of climate change decreased along with the coverage fraction from the higher, median and then lower levels. The climate change can explain 34% of the variability in the NDVI time series of the areas with a higher fraction of grassland coverage, while it was 31% for the median fraction and 20% for the lower fraction. This study is the first to use the 30 m NDVI dataset spanning nearly 30 years to analyze the spatial and temporal variability and climate impacts in the alpine grasslands of the Three-River Headwater region of the Qinghai-Tibet Plateau. The results provide a basis for assessments on the ecological management effects and ecological quality based on long-term baseline data with a higher spatial resolution.

Effects of competition and habitat heterogeneity on native‐exotic plant richness relationships across spatial scales

AbstractAimThe biotic resistance hypothesis posits that greater native species richness limits invasions of exotic species. However, negative native‐exotic richness relationships (NERRs) may reverse with increasing spatial scale, seemingly refuting the hypothesis. Here, we explore the effects of species competitive interactions, environmental factors, habitat heterogeneity and vertical vegetation tiers on the NERRs across spatial scales in native forests.LocationNew Zealand.MethodsWe combined vegetation, land cover and climate data to predict exotic richness from native richness at different vertical tiers (ground to canopy), land cover, plant competition (tree basal area, native ground cover), mean annual temperature and total rainfall. We considered four spatial scales, from single 20 × 20 m plots on an 8‐km grid to groups of plots across grids up to 128 km. Habitat heterogeneity was measured using the variance of climatic conditions among plots within a group.ResultsA negative native tree‐exotic richness relationship (NTERR) was observed at plot level but reversed with increasing spatial scale. Species competitive interactions showed a negative relationship with exotic richness at small/intermediate scales (≤32 km). Rainfall and temperature heterogeneity contributed to the positive NTERR at the largest scale. Adjacent exotic grassland cover had a positive relationship with exotic richness across all scales but did not prevent the NTERR from reversing.Main conclusionsOur analysis shows the importance of considering vegetation structure and adjacent land covers, along with spatial heterogeneity and climatic factors, when testing the biotic resistance hypothesis in forest ecosystems. There is a clear indication that biotic resistance is primarily driven by native trees in the overstorey, probably by limiting resources available to ground tier plants. The results support the notion that the NERR is driven by competitive interspecific interactions at small spatial scales and by habitat heterogeneity at larger scales.

Analysis of soil erosion characteristics in small watershed of the loess tableland Plateau of China

Soil is an essentially limited natural resource that natural and human-induced processes have both generated and damaged. Soil degradation has become one of the most crucial socio-economic and environmental problems since it produces deterioration in productivity and quality of soil resources. Soil erosion, a natural phenomenon that causes degradation of soil and, curves the soil surface away from natural physical forces. To reveal the main factors influencing the spatial distribution of soil erosion in the small watershed of the Loess Plateau, the present study has investigated the synergistic as well as the independent influence of land use, vegetation coverage, and slope on the spatial distribution characteristics of soil erosion in the Wangdonggou watershed in 2015. Soil samples have been collected and analyzed in the laboratory together with high-resolution satellite imagery and meteorological data and derived data from digital elevation model (DEM). The results have shown that soil erosion in Wangdonggou watershed in 2015 has been characterized by a slight erosion, highlighting a gradually increased intensity from North to South. Among different land-uses, woodland and grassland have caused more than 50% soil erosion in the study area, and the areas with vegetation coverage of ≥ 50% have been the main source of soil erosion, and they have been all affected by slope. Furthermore, the practice of expanding vegetation presence on the lower coverage of woodland and grassland, particularly where the slope is between 15°∼45°, and converting sloping woodland and grassland to the terrace have seemed to be effective strategies for controlling soil erosion in the Wangdonggou watershed. Finally, the current study has revealed that the RUSLE-GIS integrated model could be a useful tool to quantitatively and spatially map soil erosion at the watershed scale in the Loess Plateau, taking into account the provision of landscape services.

Evaluating malaria prevalence and land cover across varying transmission intensity in Tanzania using a cross-sectional survey of school-aged children

BackgroundTransmission of malaria in sub-Saharan Africa has become increasingly stratified following decades of malaria control interventions. The extent to which environmental and land cover risk factors for malaria may differ across distinct strata of transmission intensity is not well known and could provide actionable targets to maximize the success of malaria control efforts.MethodsThis study used cross-sectional malaria survey data from a nationally representative cohort of school-aged children in Tanzania, and satellite-derived measures for environmental features and land cover. Hierarchical logistic regression models were applied to evaluate associations between land cover and malaria prevalence within three distinct strata of transmission intensity: low and unstable, moderate and seasonal, and high and perennial.ResultsIn areas with low malaria transmission, each 10-percentage point increase in cropland cover was associated with an increase in malaria prevalence odds of 2.44 (95% UI: 1.27, 5.11). However, at moderate and higher levels of transmission intensity, no association between cropland cover and malaria prevalence was detected. Small associations were observed between greater grassland cover and greater malaria prevalence in high intensity settings (prevalence odds ratio (POR): 1.10, 95% UI: 1.00, 1.21), and between greater forest cover and reduced malaria prevalence in low transmission areas (POR: 0.74, 95% UI: 0.51, 1.03), however the uncertainty intervals of both estimates included the null.ConclusionsThe intensity of malaria transmission appears to modify relationships between land cover and malaria prevalence among school-aged children in Tanzania. In particular, greater cropland cover was positively associated with increased malaria prevalence in areas with low transmission intensity and presents an actionable target for environmental vector control interventions to complement current malaria control activities. As areas are nearing malaria elimination, it is important to re-evaluate environmental risk factors and employ appropriate interventions to effectively address low-level malaria transmission.

Forest structure and seasonally inundated grassland shape tropical mammal communities under moderate disturbance

AbstractTropical biodiversity is threatened globally by anthropogenic disturbances, particularly forest degradation and overhunting. Where large mammals have been extirpated, smaller bodied “mesomammals” may play an important ecological role (e.g., as seed dispersers). However, these species are disproportionally affected by overhunting for wildlife trade markets and are routinely understudied as they tend to be rare, cryptic, and nocturnal. Few studies have examined spatiotemporal responses to anthropogenic disturbance by mesomammals at the community level, which may identify imbalances within an ecosystem that could threaten species persistence. We deployed camera traps throughout Cat Tien National Park (i.e., Nam Cat Tien area), southern Vietnam, to (1) identify long‐term changes in terrestrial mesomammal richness and (2) evaluate the effects of forest structure and anthropogenic disturbance on an 18‐species mesomammal community within a historically disturbed tropical forest using hierarchical Bayesian community occupancy models. We found that site occupancy was driven by the interaction between distance to seasonally inundated grassland and absolute forest cover (basal area per hectare). This may be due to the combination of intact forest benefits (refuge from predators and hunters, denning sites) and early successional grassland resources (forage quality), as well as high levels of tolerance for disturbed forest among the largely generalist mesomammal community of Nam Cat Tien. We found no negative effects of current anthropogenic factors at the community level. However, we did find that four disturbance‐tolerant small carnivores have been extirpated since the 1990s and continued human presence in the park suggests that hunting and snaring remain an acute threat to native mesomammals. Without continued efforts to address the unsustainable harvest of wildlife, Southeast Asian's remaining mesomammals are at risk of extirpation despite resilience to moderate levels of disturbance.

Factors Associated With Severe Fever With Thrombocytopenia Syndrome in Endemic Areas of China.

ObjectiveTo explore the influence of climatic, environmental and socioeconomic factors on SFTS occurrence in Shandong Province, China.MethodsWe used generalized additive model to estimate the association between SFTS cases and climatic factors, environmental factors and socioeconomic factors, including annual average temperature, precipitation, land cover, normalized difference vegetation index, altitude, population density, meat production, milk production, and gross domestic product (GDP).ResultsThere were a total of 4,830 cases reported in 100 (70.9%) counties and districts in Shandong Province from 2010 to 2020. The results showed that the annual average temperature, precipitation, forest and grassland coverage rate, altitude and meat production (square root transform) had a reversed “V” relationship with SFTS occurrence, with the inflection points around 12.5–13.0°C in temperature, around 650 mm in precipitation, around 0.3 in forest and grassland coverage rate, around 300 m in altitude, and around 200–300 tons in meat production (square root transform), respectively. SFTS occurrence had a “V” relationship with milk production (square root transform) and GDP (square root transform), with the inflection points around 100–200 tons in milk production (square root transform), and around 150,000–200,000 yuan in GDP (square root transform), respectively.ConclusionsClimatic, environmental, and socioeconomic factors contributed to the heterogeneous distribution of SFTS in Shandong Province, and the influence of these factors on SFTS occurrence was nonlinear.

Golden Eagle Occupancy Surveys and Monitoring Strategy in Coastal Southern California, United States

Golden eagles (Aquila chrysaetos) are of increasing conservation concern in western North America. Effective conservation measures for this wide-ranging, federally protected raptor species require monitoring frameworks that accommodate strong inference on the status of breeding populations across vast landscapes. We used a broad-scale sampling design to identify relationships between landscape conditions, detection rates, and site occupancy by territorial pairs of golden eagles in coastal southern California, United States. In 2016 and 2017, we surveyed 175 territory-sized sample sites (13.9-km2 randomly selected grid cells) up to four times each year and detected a pair of eagles at least once in 22 (12.6%) sites. The probability of detecting pairs of eagles varied substantially between years and declined with increasing amounts of forest cover at survey sites, which obscured observations of eagles during ground-based surveys. After accounting for variable detection, the mean estimate of expected site occupancy by eagle pairs was 0.156 (SE = 0.081). Site-level estimates of occupancy were greatest (&amp;gt;0.30) at sample sites with more rugged terrain conditions, &amp;lt;20% human development, and lower amounts of scrubland vegetation cover. The proportion of a sample site with open grassland or forest cover was not strongly correlated with occupancy. We estimated that approximately 16% of the 5,338-km2 sampling frame was used by resident pairs of golden eagles, corresponding to a sparsely distributed population of about 60 pairs (95% CI = 19 – 151 pairs). Our study provided baseline data for future surveys of golden eagles along with a widely applicable monitoring framework for identifying spatial conservation priorities in urbanizing landscapes.

Horizontal and vertical spatial distribution and loss of grassland in Bosnia and Herzegovina

Two databases related to grassland in Bosnia and Herzegovina (B&amp;H) have been used in this research-the Copernicus Grassland (GRA) and CORINE Land Cover (CLC). The data have been processed by using GIS tools, and the spatial distribution of grass vegetation in relation to three biogeographical and four elevation zones has been determined. By using the Copernicus Water and Wetness (WaW) database, an insight into the coverage of grass vegetation in wetlands has been obtained. In addition, the analysis of changes in databases determined the total amount and location of the largest grassland losses. Based on GRA database, B&amp;H is one of the richest countries, with 22.4% of its territory covered by grassland. According to the CLC database, pastures occupy 6.3% and natural grasslands 5.6% of the territory of B&amp;H. However, grassland is exposed to various anthropogenic and natural processes that affect its distribution, quality, functions, etc. The CLC database has been processed by extracting the grasslands (pastures and natural grasslands) and calculating their spatial coverage and changes which happened during the three six-year periods from 2000 to 2018. The trend of decreasing pasture areas and increasing natural grasslands has been noticed. The pastures are most endangered by the processes of conversion to other types of agricultural land, while natural grassland increased spatial coverage during the period 2012-2018 mostly due to the revitalization and grazing of burned areas in the region of Herzegovina. Grasslands have been particularly targeted for afforestation and cropland conversion at present.

Modeling and Predicting Land Use Land Cover Spatiotemporal Changes: A Case Study in Chalus Watershed, Iran

Land use and land cover change (LULCC) is a main driver of global environmental change and has destructive effects on the structure and function of the ecosystem. This study attempts to detect temporal and spatial changes in LULC patterns of the Chalus watershed during the last two decades using multi-temporal Landsat images and predict the future LULC changes and patterns of the Chalus watershed for the year 2040. A hybrid method between segment-based and pixel-based classification was applied for each Landsat image 2001, 2014 and 2021 to produce LULC maps of the Chalus watershed. In this study, the transition potential maps and the transition probability matrices between LULC types were provided by the Support Vector Machine (SVM) algorithm and the Markov Chain model, respectively, to project the 2021 and 2040 LULC maps. The achieved K-index values that compared the simulated LULC map with the actual LULC map of the year 2021 resulted in a Kstandard &#x003D; 0.9160, Kno &#x003D; 0.9379, Klocation &#x003D; 0.9318 and KlocationStrata &#x003D; 0.9320, showing a good agreement between the actual and simulated LULC map. Analysis of the historical LULC changes depicted that during 2001-2021, the significant increase of Agricultural land (14317 ha) and Barren area (9063 ha), and the sharp decline of Grassland (26215 ha) and Forest cover (5989 ha) were the major LULC changes in the Chalus watershed. The model predicted that Forest cover will continue to decrease from 29.46&#x0025; (50720.2667 ha) in 2021 to 25.67&#x0025; of area (44207.78694 ha) in 2040, as well as, unceasing expansion of Barren area, Agricultural land and Built-up area will be expected by 2040. Therefore, understanding the spatiotemporal dynamics of LULC change is extremely important to implement essential measures and minimize the destructive consequences of these changes.

Examining a Habitat-Weather Threshold for Northern Bobwhite Populations in the Southwestern United States

In semiarid portions of the northern bobwhite (Colinus virginianus; hereafter, bobwhite) geographic distribution, weather is a strong driver of interannual abundance. However, the strength of this relationship may depend on habitat amount. Given this habitat–weather dependence, there is likely to be a threshold value for habitat that determines how strongly a bobwhite population responds to weather. Our objective was to evaluate the relationship between habitat amount and the relative influence of weather on bobwhite abundance in Texas and Oklahoma, USA and determine a potential land-cover threshold value. We collected bobwhite abundance and land-cover data from the Breeding Bird Survey and National Land Cover Database, respectively, for 2 time periods which corresponded to historical lows (2012–2013) and highs (2015–2016) of bobwhite abundance within this region. We reclassified land cover into grassland, shrubland, pastureland, cropland, forest, and urban cover, and combined grassland and shrubland categories to represent bobwhite habitat. We used weighted linear regression to model the difference between mean bobwhite abundance between each time period as a function of habitat amount, hypothesizing a positive, linear relationship given the theorized greater influence of weather on populations within higher habitat amounts. To evaluate a potential habitat threshold, we modeled mean bobwhite abundance, for each time period, and all individual land-cover variables using a generalized additive model with a negative binomial distribution. We detected a positive, linear relationship between habitat amount and the difference between high and low bobwhite populations (r2 = 0.30), per our hypothesis. Models of land-cover variables differed between low- and high-abundance time periods. The time period of lower abundance (2012–2013) model included all land-cover variables except cropland and showed significant positive, linear relationships with grass and hay cover, and negative, linear relationships with forest and urban cover. Shrubland cover was the only nonlinear term, increasing to approximately 50–60% cover, then decreasing sharply with increasing cover. Deviance explained for this model was 41.2%. For the period of high abundance (2015–2016) the model explained approximately 25% of the deviance and was reduced to only negative, linear relationships with forest and urban cover. Our results provide some evidence toward the habitat–weather threshold hypothesis. Additionally, while no land-cover values showed a threshold-like relationship with bobwhite abundance, we did document differences in variable selection for each time period. Stressors on bobwhite habitat seem to have a more dramatic impact on bobwhite populations than available habitat, especially in periods of higher abundance, whereas periods of lower

Projecting the remaining habitat for the western spadefoot (Spea hammondii) in heavily urbanized southern California

Extensive urbanization in coastal southern California has reduced natural habitat in this biodiversity hotspot. To better conserve ecological communities, state and federal agencies, along with local jurisdictions and private stakeholders, developed regional conservation plans for southern California. Although many protected areas exist within this region, the patchwork nature of these protected areas might not provide good coverage for species that require multiple habitat components, such as amphibians with complex life histories. Because of declines in the past century, the status of the western spadefoot ( Spea hammondii ) in southern California is of concern to state and federal wildlife agencies. Species distribution models (SDMs) can aid in determining the conservation status of imperiled species by projecting where suitable habitat remains and how much is protected from further development. We built SDMs that integrated site-occupancy data from systematic pitfall trapping surveys and presence-only data from biodiversity databases and citizen science platforms to project the current distribution of western spadefoots in southern California. Western spadefoot occurrence was positively related to the cover of grassland or shrub/scrub and the % sand in the soil within a 1000 m buffer, and was negatively related to slope, elevation, and distance to ephemeral streams or vernal pools. Most of the remaining unprotected habitat for western spadefoots is in the southern half of its historical range in western San Diego and Riverside counties. A few large tracts of spadefoot habitat exist on U.S. Department of Defense lands and smaller tracts remain on ecological reserves owned by state and local government agencies. Only small patches of habitat remain in the northern half of this clade’s historical range in Ventura, Orange, Los Angeles, and San Bernardino counties. Existing regional conservation plans provide ostensible spatial coverage of the majority of extant habitat for western spadefoots in southern California, but most of the habitat within the jurisdiction of these plans lacks formal protection, exposing this species to further declines as urbanization continues in the 21st century.

Rapid estimation of fractional vegetation cover in grasslands using smartphones

Measurements of fractional vegetation cover (FVC) are important for monitoring grassland growth and predicting aboveground biomass. Thus, a method to rapidly estimate grassland FVC is highly desired. Although smartphones provide a faster and less expensive method for estimating grassland FVC than satellites and unmanned aerial vehicles, their accuracy is not well understood. Here, we evaluated the use of smartphones to accurately estimate grassland FVC by taking photos in direct and indirect sunlight at three time points (8:00 a.m., 12:00 p.m. and 4:00 p.m.). We found that smartphone photography could be applied to grassland FVC estimation by extracting a specified percentile of color vegetation index (VIC) to reduce the effect of bright lighting. The 60th percentile value was more suitable for estimating grassland FVC than the 90th percentile, which was proposed in a previous study. We also found that extracting the 60th percentile VIC value from smartphone photos taken at noon under direct sunlight efficiently minimized the influence of lighting on estimated grassland FVC. We propose a model based on the VIC percentile method that can quickly estimate grassland FVC using smartphone photography. This model is very versatile for estimating FVC in semi-arid grasslands. Our findings show that using smartphone photos to quickly estimate grassland FVC is feasible and could provide a practical solution to quickly and accurately estimate grassland FVC.

Conserving Working Rangelands: A Social–Ecological Case Study from Northeastern Colorado

Land changes in rangeland systems cascade through interconnected social and ecological spheres, affecting both humans and the environment. This study applied a multi-method approach to examine the causes and consequences of change in two rangeland communities in northeastern (NE) Colorado. First, this study used a Random Forest supervised classifier to analyze 36 years of land-cover data and create a land-cover/use change classification model. Second, the research team analyzed transcripts of interviews with 32 ranchers, examining how ranchers’ adaptive strategies influence land-cover change trends. Lastly, the analysis integrated the quantitative and qualitative data, constructing a social–ecological rangeland change conceptual model. This study found that the cultivated area decreased in both study sites from 1984–2019, with 16.0% and 18.7% of each site transitioning out of the cultivated area. Moreover, 10.3% and 18.4% of each site, respectively, transitioned to herbaceous/grassland cover from 1984–2019. The qualitative analysis identified the role of conservation policies, such as open space programs, on land change. Also, despite the relatively small area that transitioned to developed cover—1.83% and 0.183% of each site—participants emphasized that the associated demographic and cultural shifts drive land-use change. This study highlights that while rangelands are undergoing social–ecological change, land-use decisions and land conservation programs can help mitigate the global trend of declining rangeland and grassland cover.

Topographic Variation in Forest Expansion Processes across a Mosaic Landscape in Western Canada

Changes to historic fire and grazing regimes have been associated with the expansion of tree cover at forest–grassland boundaries. We evaluated forest expansion across a mosaic landscape in western Canada using aerial photos, airborne laser scanning, and field transects. The annual rate of forest expansion (0.12%) was on the low end of rates documented across North America and was greater from the 1970s to the 1990s than from the 1990s to 2018. Most forest expansion occurred within 50 m of established forests, and 68% of all tree regeneration in grasslands was within 15 m of the forest edge. The intensity of cattle grazing did not affect the tree regeneration density. Despite the slow pace of land cover change, grassland areas near the forest edge had an average of 20% canopy cover and 9 m canopy height, indicating the presence of tall but sporadic trees. The rate of forest expansion, density of tree regeneration, and tree cover within grasslands were all greater at lower elevations where trembling aspen (Populus tremuloides) and white spruce (Picea glauca) were the dominant tree species. We conclude that proportions of forest–grassland cover on this landscape are not expected to change dramatically in the absence of major fire over the next several decades.