Conversion Of Grassland Research Articles

Spatial differentiation of ecosystem service value in an arid region: A case study of the Tarim River Basin, Xinjiang

Ecosystem service value (ESV) in arid regions is subject to multiple factors, and the main factors affecting ESV may vary in different regions. However, there are fewer studies concerned with the spatial heterogeneity of the factors influencing ESV in arid regions. In this study, we selected five typical sub-basins of the Tarim River Basin (TRB), including the Kashghar (KRB), the Weigan (WRB), the Dinah (DRB), the Keriya (KRRB), and the Qarqan (QRB) river basins, as research objects to investigate the ESV. Firstly, we estimated the ESV by utilizing the LULC data sets and benefits transfer methods. Next, we conducted a systematic analysis of the spatial variations of ESV. Finally, we analyzed the driving factors of spatial variation of ESV using a geographical detector model. Our results show that: (1) During 1990–2018, various land use types underwent complex dynamic transformations, including the conversion of grassland and water bodies into cropland and unused land. (2) Over the 29-year study period, the five studied TRB sub-basins show a decreasing trend in total ESV during 1990–2018, with the largest reduction observed in KRRB (-230.64 × 107 USD), followed by WRB (-105.43 × 107 USD), and the smallest in QRB (-10.31 × 107 USD). Moreover, environment depuration (ED), climate regulation (CR), hydrological regulation (HR), and soil conservation (SC) were the key components of high service value in the study area. (3) The spatial distribution of ESV demonstrated strong positive spatial autocorrelation, with high and low values clustering on a spatial scale. Our analysis of driving forces revealed that spatial differentiation is the result of a synergistic effect of natural factors such as elevation, temperature, and precipitation, as well as anthropogenic and socioeconomic factors. Based on the results obtained, our study serves as a crucial foundation for implementing necessary measures aimed at achieving ecological security and promoting sustainable development in the TRB area.

Natural grassland conversion to cultivated pastures increases soil microbial niche specialization with consequences for ecological processes

The conversion of natural grasslands to cultivated pastures has a profound effect on the soil habitat conditions, influencing the proportion of soil specialist and generalist microbes, with consequences for the assembly of microbial communities. This often leads to the homogenization of the microbial community and thus favoring stochastic assembly processes. However, there is still a gap in understanding the effect of conversion from natural grasslands to cultivated pastures on soil microbial ecological processes. Therefore, we aimed to investigate the assembly patterns of microbial communities and evaluate the ecological models for generalists and specialist microbes along a grassland management intensification gradient. Through 16S rRNA amplicon sequencing, we found that the conversion of natural grasslands to cultivated pastures has increased the number of microbial specialists, resulting in stochastic assembly processes due to the decrease in plant diversity. Moreover, the ecological processes governing the assembly of microbial communities were affected by soil and vegetation management. The perennial pasture was more affected by homogenizing selection, owing to the lower plant diversity and uniform plant covering and root development. We have found that the generalists in the grasslands are shaped by niche-based models, while the specialists in natural grasslands are more stochastic in nature. For improved pastures, we have found that lognormal and preemption models are more predominant, suggesting that homogenizing dispersal is more predominant than variable selection. We highlight it is essential to comprehend these assembly models and ecological processes to ensure plant-microbe supporting and provisioning ecosystem services for cattle, and humans while establishing management strategies and conservation policy priorities.

Spatiotemporal distribution and attribution of carbon sequestration in karst rocky desertification land in southern China

<p>To mitigate the intensification of desertification and land degradation in karst areas of southern China, since the late 1990s, the Chinese government has implemented a series of ecological restoration projects. In the past couple of decades, the carbon sequestration potential of karst rocky desertification land increased significantly. However, few studies have explored the characteristics and driving mechanisms of carbon sequestration in karst areas. This study aimed to quantify the spatiotemporal patterns, trends, and drivers of carbon sequestration in the Huajiang River Basin, a typical karst basin, in southern China during 2000-2020 and its five geographic zones via the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model. The five zones of the karst basin exhibited the following characteristics: (I) good natural background condition with positive feedback human intervention; (II) poor natural background condition with increased negative and decreased positive feedback human interventions; (III) poor natural background condition with increased positive and decreased negative feedback human interventions; (IV) non-karst land; and (V) poor natural background condition with no significant positive and negative feedback human interventions and with heavy reliance on natural ecosystem recovery. The results were four-fold. First, the Huajiang River Basin showed a significant increasing trend of carbon sequestration. The spatiotemporal variation of carbon sequestration significantly differed among the five zones (Ⅴ > Ⅲ > Ⅳ > Ⅱ > Ⅰ). The stability of carbon sequestration was lowest in zone III. Second, a 20-y<span style="font-family: 'Times New Roman';">ear</span> land-use/cover change directly affected the level of carbon sequestration. The conversion of cropland, grassland, and woodland to shrubland was the main reason for the increased carbon sequestration in zone I. Third, carbon sequestration was negatively correlated with the desertification level of karst rocky areas. The spatial distributions of moderate, serious, and extremely strong desertification levels in zone II showed an increasing trend. Zones I, III, and V exhibited no significant desertification. Finally, the integrated ecological management against desertification increased carbon sequestration. Negative feedback human interventions (e.g., quarrying) exerted a significant disturbing impact on carbon sequestration that needs to be addressed in the formulation of management practices.</p>

Assessment and Prediction of Landscape Ecological Risk from Land Use Change in Xinjiang, China

Land use change has significant impacts on the regional and global environment; thus, in-depth research on the associated ecological risks is necessary for promoting ecological restoration and sustainable development. Xinjiang, China, is characterized by a fragile ecological environment, and this study aimed to predict the land use change in the region in 2030 under different scenarios, including natural development, ecological conservation, and urban development, by using the PLUS model based on land use data from 2000, 2010, and 2020. Based on the landscape structure of regional ecosystems, we developed a comprehensive ecological risk assessment framework by utilizing a combination of landscape disturbance index, vulnerability index, and loss index. This framework allowed us to evaluate the spatiotemporal patterns and variations of landscape ecological risks under different scenarios in 2030. The study results indicate the following: (1) During the period from 2000 to 2020, the primary landscape type in Xinjiang was unused land. However, significant changes were observed in the area of cultivated land, mainly due to the conversion of grassland and construction land. The expansion of construction land during the urbanization process resulted in a decline in ecological landscapes, such as grassland, thereby weakening the ecosystem’s stability. (2) Under different simulation scenarios, the urban development scenario primarily led to the conversion of unused land into construction land, which is beneficial for economic development. On the other hand, the ecological conservation scenario resulted in a modest increase in construction land and a transformation of unused land into forest and grassland, which aligns with the principles of sustainable development. (3) Different scenarios in 2030 result in varying degrees of changes in each landscape type in Xinjiang, with the spatial distribution characteristics of landscape ecological risks remaining similar to those observed in 2020. Notably, under the urban development scenario, the area of lowest and medium risk areas decreases significantly while the area of higher and highest risk areas increases substantially. Conversely, under the ecological conservation scenario, the area of the lowest risk areas experiences a more significant increase. (4) Overall, the spatial differences in the ecological risk of Xinjiang’s landscape are significant, with HH and LL clustering types predominating and presenting a polarization pattern. The distribution pattern is low in the north and high in the central and southern parts of the study area.

Changes in soil fertility and microbial communities following cultivation of native grassland in Horqin Sandy Land, China: a 60-year chronosequence

BackgroundGrassland conversion to cropland is a prevailing change of land use in traditionally nomadic areas, especially in the Mongolian Plateau. We investigated the effects of grassland conversion followed by continuous cultivation on soil properties and microbial community characteristics in Horqin Sandy Land, a typical agro-pastoral transition zone of Northern China. Soil samples were collected from the topsoil (upper 20 cm) across a 60-year cultivation chronosequence (5, 15, 25, 35 and 60 years) and unconverted native grassland. Soil physico-chemical properties were determined and high-throughput sequencing was used to assess microbial community diversity and composition.ResultsGrassland cultivation resulted in changes to soil properties in both the short and longer term. Initially, it significantly increased soil bulk density (BD), electrical conductivity (EC), soil total nitrogen (TN), available phosphorus (AP) and available potassium (AK) concentrations, while reducing soil water content (SWC) and soil organic carbon content (SOC). Over the next 35–55 years of continuous cultivation, the trend for most of these characteristics was of reversion towards values nearer to those of native grassland, except for SOC which remained highly depleted. Cultivation of grassland substantially altered soil microbial communities at phylum level but there was no significant difference in microbial α-diversity between native grassland and any cropland. However, soil bacterial and fungal community structures at phylum level in the croplands of all cultivation years were different from those in the native grasslands. Heatmaps further revealed that bacterial and fungal structures in cropland tended to become more similar to native grassland after 15 and 25 years of cultivation, respectively. Redundancy analysis indicated that SOC, EC and BD were primary determinants of microbial community composition and diversity.ConclusionsThese findings suggest that agricultural cultivation of grassland has considerable effects on soil fertility and microbial characteristics of Horqin Sandy Land. Intensive high-yield forage grass production is proposed as an alternative to avoid further native grassland reclamation, while meeting the grazing development needs in the ethnic minority settlements of eco-fragile regions.

Temporal and spatial change of habitat quality and its driving forces: The case of Tacheng region, China

Habitat quality assessment is an important basis for ecological restoration practice. Taking the Tacheng region as an example, the InVEST model was used to evaluate the habitat quality of the Tacheng region in five periods from 2000 to 2020, and analyze the reasons for its changes, to provide theoretical guidance for ecological restoration practice in arid areas. The conclusions were that from 2000 to 2020, the habitat quality in the Tacheng region improved slightly, and the value of the habitat index in the Tacheng region was the highest in 2010, which was 0.577, and then decreased slightly. The habitat quality in the Tacheng region was significantly influenced by land use type conversion and precipitation. The change in land use type directly affected the change in habitat quality. The study region is located in an arid area; the forest land and grassland native to the region have more vegetation communities and genera of species and can be self-sustaining and resilient to disturbance, having high scores for habitat quality. The species of arable land is a monoculture; it cannot be self-sustaining and resilient to disturbance, and though it has high vegetation cover, the value of habitat quality is lower than that of forestland and grassland. The vegetation of unused land is rare, and the ecosystem of unused land is sensitive and vulnerable; the habitat quality scores are very low. The conversion of forest land, grassland, arable land, and unused land would directly affect the value of habitat quality, and conversion was the main factor affecting the change in habitat quality. In addition, precipitation was also an important factor affecting the change in habitat quality in the Tacheng region, which affected the biomass of natural vegetation and then affected the habitat quality. The results provided the temporal and spatial change of habitat quality and its driving forces in the Tacheng region, which helps determine appropriate measures and sites in ecological restoration projects.

Grassland management intensification affects the soil fauna in a subtropical highland

AbstractThe conversion of natural grasslands to cultivated pastures can have a significant impact on the composition and structure of soil macro‐ and mesofauna groups, compromising the resilience of these organisms and the ecosystem services they provide. We studied the responses of these groups to increasing levels of soil disturbance across a gradient of four land management practices: Natural grassland (NG), Improved‐natural grassland (IG), Perennial‐cultivated pasture (PP), and Annual‐cultivated pasture (AP). The NG area had a higher abundance of macrofauna, greater dominance of certain groups, particularly Isoptera, and a lower abundance of mesofauna. On the other hand, the IG area had a higher abundance and diversity of macro‐ and mesofauna, with a lower dominance of specific groups. The PP area had a higher abundance of Coleoptera, Oligochaeta, and Hemiptera, whereas the AP area, despite soil disturbance, showed a higher abundance of mesofauna, particularly mites, Collembola, and Enchytraeidae, but lower diversity. Different grassland management practices have significantly altered the composition and structure of macro‐ and mesofauna groups, resulting in high dissimilarity between communities. We recommend IG as a more productive and sustainable alternative to the total replacement of natural vegetation (NG) with intensified converted pastures (PP and AP), as it maintains soil fauna diversity and ecosystem services.

Environmental drivers of spatio-temporal dynamics in floodplain vegetation: grasslands as habitat for megafauna in Bardia National Park (Nepal)

Abstract. Disturbance-dependent grasslands, often associated with hydromorphological and fire dynamics, are threatened, especially in subtropical climates. In the Nepalese and Indian Terai Arc Landscape at the foot of the Himalayas, natural and cultural grasslands serve a viable role for greater one-horned rhinoceros (Rhinoceros unicornis) and for grazers that form prey of the Royal Bengal tiger (Panthera tigris). The grasslands are vulnerable to encroachment of forest. We aimed to establish the effects of environmental drivers, in particular river discharge, river channel dynamics, precipitation and forest fires, on the spatio-temporal dynamics of these grasslands. The study area is the floodplain of the eastern branch of the Karnali River and adjacent western part of Bardia National Park. We created annual time series (1993–2019) of land cover with the use of field data, remotely sensed LANDSAT imagery and a supervised classification model. Additionally, we analysed the pattern of grassland patches and aerial photographs of 1964. Between 1964 and 2019, grassland patches decreased in abundance and size due to encroachment of forest. Outside the floodplain, conversion of grassland to bare substrate coincides with extreme precipitation events. Within the floodplain, conversion of grassland to bare substrate correlates with the magnitude of the annual peak discharge of the bifurcated Karnali River. Since 2009, however, this correlation is absent due to a shift of the main discharge channel to the western branch of the Karnali River. Consequently, alluvial tall grasslands (Saccharum spontaneum dominant) have vastly expanded between 2009 and 2019. Because the hydromorphological processes in the floodplain have become more static, other sources of disturbances – local flooding of ephemeral streams, anthropogenic maintenance, grazing and fires – are more paramount to prevent encroachment of grasslands. Altogether, our findings underscore that a change in the environmental drivers impact the surface area and heterogeneity of grassland patches in the landscape, which can lead to cascading effects for the grassland-dependent megafauna.

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

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

Assessing the vulnerability of grasslands in Gannan of China under the dual effects of climate change and human activities

Climate change and human activities are two major drivers of grasslands degradation. Understanding the vulnerability of grasslands to both drives is of great importance for grassland conservation. This research established a vulnerability assessment model with historical and future the Normalized Difference Vegetation Index (NDVI), which was predicted by an optimized spatiotemporal NDVI prediction model, and then examined the vulnerability of grasslands under climate change and human activities in Gannan Prefecture on the north-eastern Qinghai-Tibet Plateau. Our results show that Gannan grasslands would show a vulnerability pattern of higher in the west and lower in the east under climate change and human activities. More than 46 % and 17 % of the region will become highly and medium vulnerable areas in the future, mainly concentrated in Maqu, Luqu and Xiahe counties in the west, southwest and northwest of Gannan. Specifically, the vulnerability is the lowest under the future climate scenario of moderate carbon emissions (i.e. RCP 4.5). Land use types such as forest land, unutilized land and cultivated land conversion to grassland could partially offset the vulnerability mainly caused climate change, while the conversion of grassland to unutilized land, forest land and cultivated land would increase the vulnerability of grassland. Our results would help to deepen the understanding of the patterns and main drivers of Gannan grasslands vulnerability under the impacts of climate change and human activities, and provide theoretical basis for the development of corresponding grassland management policies.

Influence of the ecosystem conversion process on the carbon and water cycles in different regions of China

Ecosystem conversion processes in different regions of China have different impacts on carbon and water cycle changes. Water use efficiency (WUE) is a key factor in coupling ecosystem carbon and water cycles, and it is important to quantify the effects of ecosystem conversional processes on the WUE in different regions of China to improve our understanding of the effects of ecological restoration projects and ecosystem conversional processes on carbon and water cycles in different regions. In this study, we proposed a dual–type extraction algorithm for ecosystem conversion processes (DTEA–ECP) to study the impact of ecosystem conversion processes on the WUE in different regions of China from 2001 to 2020. Our results showed that in the 2001–2020 period, the area of barren ecosystem conversion to grassland ecosystem increased at the fastest rate (4.29*103 km2 y-1). In the snow climate zone with dry winters and warm summers, projects returning cropland to forest were beneficial for improving WUE. In the northwestern part of the semiarid climate zone, returning cropland to grassland was beneficial for increasing the WUE of the ecosystem, while in northeastern China, the change in WUE after the conversion of grassland ecosystem to cropland ecosystem was not significant. WUE decreased after the conversion of forest ecosystems to grassland ecosystems, while WUE increased after the conversion of grassland ecosystems to forest ecosystems. This study identified where it was most suitable to plant each vegetation type and can help with the implementation of ecological projects such as afforestation, returning farmland to forest and grass, grassland protection and wind and sand management. The results provide information support for the in-depth development of national greening and low-carbon land restoration, improve vegetation carbon sink capacity, enhance carbon emission reduction and carbon sequestration, and help to achieve the goal of peak carbon and carbon neutrality.

Divergent effects of converting different types of ecosystems to tree plantations on soil water holding characteristics: A meta-analysis

Human activities have been responsible for substantial land use changes, including the conversion of different ecosystems to tree plantations (thereafter plantations). Despite that these land use changes can have significant effects on hydrological processes in soils, a global perspective on how land use changes may impact soil water holding characteristics is still lacking. Here we performed a meta-analysis with 11078 paired observations collected from 330 peer-reviewed publications to assess how the conversion of croplands, deserts, grasslands, primary forests, secondary forests, shrublands, and bare lands to plantations might affect soil water content (WC), water holding capacity (WHC), saturated water content (SWC), and capillary holding water (CHW). We found that converting croplands to plantations significantly increased WHC and CHW by 14.4% and 30.1%, respectively. Converting deserts into plantations increased CHW by 25.3%, while converting grasslands to plantations increased WHC by 12.7%. The conversion of bare lands to plantations increased soil SWC and CHW by 37.7% and 41.5%, respectively. In contrast, cropland and grassland conversion to plantations decreased soil WC by 17.8% and 15.6%, respectively. The conversion of primary forests, secondary forests, and shrublands to plantations did not affect soil WC, WHC, SWC, or CHW. Finally, the effects of land use change on soil water holding characteristics were regulated by multiple moderator variables, with climate, geographical location, and tree species functional types being the most important. Overall, our quantitative analyses clearly showed how ecosystem conversion affected soil water holding characteristics at the global scale, which will help us to better understand and predict soil hydrological processes following land use changes under future global change.

Inexorable land degradation due to agriculture expansion in South American Pampa

From 1985 onwards, South America has undergone a major expansion in agriculture at the expense of native vegetation (for example, native Pampa grassland). As an emblematic crop, the surface area cultivated with soybeans has increased by 1,000% between 1990 and 2020 in Uruguay. The environmental consequences of this massive land-use conversion on soil degradation remain poorly documented, although agriculture expansion is projected to continue to increase in the coming years in South America. In this study, sediment cores were collected in reservoirs located downstream of two contrasted agricultural catchments draining the Rio Negro River (Uruguay) to reconstruct the sediment dynamics and the sources of erosion associated with this expansion. Results demonstrated the occurrence of two periods of acceleration of sediment delivery since the 1980s. The first period of acceleration was recorded in the mid-1990s and was related to afforestation programs. The second and larger acceleration phase was recorded after 2000 during the soybean crop expansion. This period was marked by a greater supply of sediment from the native grassland source, highlighting the impact of agriculture expansion at the expense of native vegetation. Conservation measures should therefore be urgently taken to preserve biodiversity and soil functions in this region. The impacts on soil degradation of the massive land-use conversion of South American Pampa grasslands to agriculture are not well documented. This study estimates, over the period 1982–2019, the impacts of such conversion on the sediment cascade and how soil and water resources are affected as a result.

Spatiotemporal heterogeneity correction in land ecosystem services and its value assessment: a case study of the Loess Plateau of China.

The considerable variation in structures and functions of different ecosystems leads to highly variable ecosystem service values (ESVs). Consequently, the accurate quantification of ESVs can better assess and reflect impacts of land use and cover changes (LUCC) on ecosystem services. In the land use simulations of this study, a CA-Markov model was chosen and nine factors affecting land use change were evaluated, followed by the construction of a multi-criteria evaluation method to simulate land use scenarios between 2025 and 2030 on the Loess Plateau. Six key ecological indicators (economy, water production, net primary plant productivity, habitat quality, accessibility, and soil conservation) were used to correct for spatiotemporal heterogeneity within the terrestrial ESV equivalent weight table for China to obtain an ESV equivalent weight factor table that is applicable to the Loess Plateau. Using the newly corrected table, ESVs for the Loess Plateau region were estimated between 1995 and 2030, and the impacts of LUCC on ESVs were analyzed. The Kappa values for the 2015 land use simulation results were 0.80 and 0.83, which were greater than 0.75, indicating that the CA-Markov model simulations were accurate. Throughout the study period, the largest increases in land use type area were for built-up areas and forest lands, with built-up areas primarily derived from conversions of cultivated lands and grasslands, and forest land increases primarily coming from conversion of grasslands. ESVs increased overall by 933.97 × 108 yuan and 312.86 × 108 yuan from 1995 to 2018 and 2018 to 2030, respectively. The three largest contributors to ecosystem services among land use types were moderate grasses, shrublands, and dense grasslands. In conclusion, ESVs for the Loess Plateau steadily increased year by year from 1995 to 2030, indicating that ecological restoration projects played major roles in improving the stability and sustainability of the region's ecosystems.

Spatiotemporal risk factors predict landscape‐scale survivorship for a northern ungulate

AbstractEffective wildlife conservation requires decomposing the drivers of population dynamics for species affected by anthropogenic habitat alterations. Ungulates are often the focus of management actions to restore habitat and maintain connectivity as they are sensitive to landscape disturbances. We used Bayesian proportional hazards models to assess anthropogenic risk factors that could potentially predict landscape‐scale survivorship for pronghorn (Antilocapra americana) in the Northern Sagebrush Steppe ecosystem, where extensive habitat alterations occurred from the conversion of native sagebrush grasslands to agricultural lands. Using 170 adult female pronghorn monitored from 2003 to 2011, we tested the importance of linear features (road and fence densities) and forage productivity (maximum decadal normalized difference vegetation index [NDVI]) for spatiotemporal pronghorn mortality risk, while accounting for a seasonally varying proxy of snow depth. We found moderate support for the effects of linear features on mortality risk as coefficient estimates translated to predicted declines in survivorship of 27.1% over the observed range of road densities (0–1.4 km/km2) and 11.8% over the range of fence densities (0–6.1 km/km2) encountered by pronghorn. Our results also suggested that agricultural areas could act as ecological traps for pronghorn, based on mortality risk increasing by a factor of 14.3% with every 0.1 increase in maximum decadal NDVI in summer (range = 0.38–0.73). Like our previous findings, we found considerable support for the effects of average depth (in centimeters) of snow water equivalent (SWE; SWE depth = snow depth × snow density/water density) within pronghorn seasonal ranges, with mortality risk increasing by 45.7% with every 1 cm increase in SWE depth (range = 0–5.37 cm). We then developed the first broadscale, spatially explicit map of predicted annual pronghorn survivorship based on anthropogenic features and environmental gradients to identify areas for conservation and habitat restoration efforts. These efforts to highlight anthropogenic risk factors on the landscape will hopefully support conservation and habitat restoration for pronghorn populations at the northern periphery of their range.

Influence of cropland on resource selection by pronghorn

AbstractPronghorn (Antilocapra americana) are a grassland specialist that have experienced a >60% reduction in their historical range due to habitat fragmentation and encroachment of woody vegetation. Pronghorn populations are increasing in the Texas Panhandle despite conversion of grassland to cropland (27–43% of the regional landscape) and associated fragmentation. We hypothesized that pronghorn avoid cropland when selecting seasonal home ranges and avoid cropland within their home ranges. We captured 64 adult pronghorn of equal sex ratios in both the High Plains (n = 32) and Rolling Plains (n = 32) ecoregions of Texas, USA, during February 2017 and fitted them with iridium satellite global positioning system (GPS) collars. We collared 27 additional pronghorn in 2018 to account for mortalities and collar failures. We estimated resource selection functions for the High Plains and Rolling Plains populations using mixed‐effects logistic regression at the home range (second order) and within home range (third order) scales separately for each ecoregion and season (fawning, summer, rut, and winter). Our hypothesis that pronghorn avoid cropland was supported in the Rolling Plains ecoregion at the home range scale; otherwise, cropland was inconsistently and seasonally important in resource selection. Furthermore, pronghorn often avoided paved roads more strongly than cropland. At the home range scale during 2017–2019, female pronghorn in the High Plains selected cropland during rut and winter. Males exhibited weak selection for cropland during rut. Within home ranges in the High Plains, female pronghorn avoided cropland during fawning in 2017, during rut in 2017 and 2018, and during winter 2019 but selected areas closer to cropland in winter 2017 and fawning 2018. Males selected areas farther from cropland during all sampling dates in 2017 and winter 2019. Avoidance and selection of cropland within home ranges also varied among seasons and years in the Rolling Plains. Overall, pronghorn avoided cropland when selecting home ranges in the Rolling Plains and cropland was otherwise inconsistently and only seasonally important in resource selection at the home range and within home range scales. We speculate that loss of pronghorn habitat to cropland in the High Plains and Rolling Plains of Texas may outweigh temporary nutritional benefits from seasonal use of crops.

Pasture management intensification shifts the soil microbiome composition and ecosystem functions

Natural grasslands are important reservoirs of animal and plant biodiversity and provide several ecosystem services, through the action of soil microorganisms. The increased demand for food, energy, and cattle activity has led to the conversion of natural grasslands to cultivated systems. However, the consequences of this conversion for soil microbial diversity and ecosystem functioning are yet to be discovered. Here, we used the 16 S rRNA amplicon sequencing and a large set of soil and environmental variables to understand the possible effects of natural grasslands to cultivated pasture conversion on the soil microbial structure, composition, diversity, and functions. The study areas followed a gradient of increasing soil disturbance intensity, as follows: Natural grassland (NG), Improved-natural grassland (IG), Perennial-cultivated pasture (PP), and Annual-cultivated pasture (AP). Natural grassland conversion to managed and cultivated pastures decreased the abundances of Acidobacteria and Verrucomicrobia, while increased α-, γ-, and δ-Proteobacteria, Gemmatimonadetes, Bacteroidetes, Patescibacteria, and Latescibacteria. The predicted functional profiles have also changed, as functions like ‘cellulolytic and symbionts/parasites’ decreased after natural to cultivated pastures conversion, while ‘nitrogen respiration’, ‘sulfur respiration’, and ‘aromatic compound degradation’ functions increased. Aboveground plant diversity decrease influenced belowground microbial diversity. The main drivers of diversity, composition, and functional potential are associated with soil attributes affected by liming, like aluminum complexation. In conclusion, we have found taxonomic and functional differences between natural and managed grasslands (NG and IG, respectively) and cultivated pastures (PP and AP), with consequences for management strategies and biodiversity conservation priorities.

Species action plan for conservation of an isolated Steppe Eagle population in Turkey

Steppe Eagle (Aquila nipalensis) is a globally Endangered (EN) species according to IUCN Red List, with a breeding range extending through the arid zones of southern Russia and Kazakhstan, from Kalmykia in the west to Dauria in the east. There is a small, isolated breeding population in Turkey, discovered in 2003, which lost contact with the main breeding range. Although there are studies carried out between 2015 and 2021, the size of the isolated population is not exactly known. To protect this small population on the brink of extinction, the General Directorate of Nature Conservation and National Parks (GDNCNP), which is officially responsible for wildlife conservation, programmed to prepare a species action plan in 2021. As part of the “Preparation, Implementation and Monitoring of Species Action Plans for Endangered Species in Turkey within the Concept of a New Methodology”, shortly “Endangered Species” project, Steppe Eagle was selected, based on a prioritization study, to be one of the pilot species for which species actions to be prepared. Field studies were conducted in the 2022 breeding season to identify threats causing stress to the Steppe Eagle. During the breeding studies in 2022, it was determined that 4 pairs of Steppe Eagles were confirmed to be breeding in Central Anatolia, and 4 pairs attempted to breed. During the field studies, threat factors were listed based on direct observations, indirect observations (nest records, mortality records, etc.), and bilateral discussions with local communities. Using the threat analysis adopted by IUCN and adapted to Turkey within the framework of the same project, a national-level threat analysis was conducted. Direct threat factors causing stress to the species were listed as conversion of grasslands into agricultural areas, excessive use of groundwater and surface water leading to the drying of wetlands, power transmission lines, human activities and grazing pressure on breeding islands in wetlands, illegal hunting, predation, researcher pressure, hybridization with Eastern Imperial Eagles (Aquila heliaca), and artificial materials in nests. Additionally, the use of rodent poisons was also identified as a potential threat. As a result of the threat analysis, the threats with the highest level of impact on the species were identified as the conversion of grasslands into agricultural areas and excessive water usage. These threats result in the transformation of steppe habitat and decrease in the species' food sources. Another high-level threat is illegal hunting. The identified threats were transferred to a problem tree and, following the method generated in the “Endangered Species” project, problem tree was transformed to a result chain. In the result chain, the selected results for eliminating/reducing threats were defined by identifying intervention points and transforming them into objectives. Activities were defined to achieve the identified objectives. Within the scope of the 10-year action plan a total of 34 activities were designed under 9 objectives to be achieved. Eight out of the 9 objectives involve conservation, and one involves research-related activities. The aim of the 10-year plan is to conserve and support the breeding population of the species in Turkey.

Wetland occupancy by duck broods in cropland‐dominated landscapes of the United States Prairie Pothole Region

AbstractThe Prairie Pothole Region (PPR) is globally important for breeding waterfowl but has been altered via wetland drainage and grassland conversion to accommodate agricultural land use. Thus, understanding the ecology of waterfowl in these highly modified landscapes is essential for their conservation. Brood occurrence is the cumulative outcome of key life‐history events including pair formation and territory establishment, nest success, and early brood survival. We applied new technological advances in brood surveying methods to understand brood use of wetlands and how land use and wetland‐specific factors influenced brood use of 413 wetlands in crop‐dominated landscapes in the PPR of Iowa, Minnesota, North Dakota, and South Dakota, USA, during summers of 2018–2020. Dynamic occupancy models combining information from 2 visits throughout the year revealed no difference among the 4 states or between private and public lands, resulting in a region‐wide annual wetland occupancy estimate of 0.41 (95% credible interval [CrI] = 0.26, 0.58). We assessed aquatic invertebrate forage availability, wetland and upland vegetation communities, and various water chemistry metrics in a subset (n = 225) of these wetlands to evaluate how landscape and wetland‐specific factors influenced occupancy. The amount of grassland surrounding wetlands was the only variable to influence occupancy at a landscape scale, while wetland size, invertebrates, fish, and vegetation communities influenced occupancy at finer scales. Closer scrutiny of wetland area revealed occupancy was greater in small wetlands after controlling for total wetland area. Our results indicate the greatest constraint on brood occupancy across crop‐dominated landscapes of the PPR in the United States was the occurrence of semipermanent wetlands suitable for brood rearing. Other factors, such as wetland vegetation or surrounding land use, had minor intervening influences on duck brood use and ducks were distributed invariant of wetland ownership or broad spatial processes occurring among states. These results demonstrated wetland conservation and restoration strategies are likely to yield gains in annual duck broods across this vast, altered, and highly modified landscape.

Community structure of medium-large mammals across a tree plantation cycle in natural grasslands of Uruguay

In temperate South America, the conversion of natural grasslands into crops and exotic tree plantations, such as with Eucalyptus sp., has reached outstanding levels, especially in the Río de la Plata Grasslands. The cycle of Eucalyptus plantations for pulp production is a very dynamic phenomenon; however, most of the studies on the impacts on biodiversity have been static and focused on the mature stage of the plantation. We studied the mammal assemblage in a grassland afforestation landscape of Uruguay to address how mammals respond to habitat complexity variation across the plantation cycle and landscape characteristics. We installed 26 camera traps for two years in four different age stages of Eucalyptus plantations and native habitats to assess mammals’ richness, composition, and intensity of habitat use. We registered 16 mammal species, 13 native and three exotics, with a sampling effort of 19,136 camera-nights. Of these species, 11 were found in the Eucalyptus plantations but with significant variability during the production cycle. Only one species was recorded at the beginning (0–2 years) of the cycle and four species at the end (8–10 years). But at intermediate ages (2–4 years), when vegetation complexity resembles a native forest structure, species richness was maximum (11 species) in the plantations and relatively close to forest richness (14 species). Species composition was also determined by habitat structure, but it was further modulated by landscape features, particularly the proximity to native forests and landscape heterogeneity. Our results demonstrated that asynchronous plantations promote spatial heterogeneity that favors mammal diversity in afforested landscapes, but for grassland mammals, additional conservation management measures are needed.