Rangeland Ecology & Management最新文献

Bottlebrush squirreltail (Elymus elymoides) and big squirreltail (Elymus multisetus) are high-priority species for restoration of millions of hectares of rangeland in the western United States that have been degraded by accelerated wildfire and introduced annual grasses. Previous research has compared potential germination and seedling performance of these species in a common environment and noted significant genetic differentiation in characteristics that are associated with their environments of origin. In this experiment, we used wet-thermal germination models and long-term simulations of seedbed microclimate to conduct a virtual reciprocal-garden analysis of the potential germination response of these species. We confirmed significant species differentiation in germination rate that appears to confer site-specific advantages for initial seedling establishment in their respective habitats of origin. Our results specifically highlight the relative importance of late-fall seeding for the more rapidly germinating E. multisetus in order to avoid early-fall germination and post-germination seedling mortality from freezing conditions in the winter. In contrast, the slower-germinating E. elymoides ssp. brevifolius A is less likely to germinate in the fall and likely avoids inherently harsher winter temperatures in the seedbed. Virtual simulations of this type might lead to identification of complex-trait genetic markers that are associated with intraspecific and interspecific adaptations to specific environments. Identification of these traits could also inform management of plant communities that are under threat from invasive weeds and climate change.

Wind and water erosion can severely impact natural resources and ecosystem services, making soil erosion management essential to sustaining agroecosystems. Land health assessment protocols, such as Interpreting Indicators of Rangeland Health (IIRH), provide valuable information to make decisions on managing soil erosion in vulnerable drylands. Using quantitative erosion models with land health assessments can further inform management decisions. For example, sediment transport estimates from the Aeolian EROsion (AERO) model and Rangeland Hydrology and Erosion Model (RHEM) can help in understanding the impacts of differences in soil and vegetation on wind and water erosion risk. In this article, we provide a conceptual basis for using AERO and RHEM to support IIRH assessments that are used extensively by managers across United States rangelands. We describe how using erosion models with IIRH can (1) improve understanding about potential erosion rates for different types of storm events; (2) support identifying areas at risk of erosion where erosion evidence is not (yet) significant; (3) increase land health assessment consistency by providing reproducible erosion indicators; (4) provide another line of evidence to support assessment conclusions about land health; and (5) improve understanding about potential erosion rates across ecologically similar sites and over time. Effectively using erosion models to support land health assessments will improve wind and water erosion management in drylands, thus helping to protect and restore these ecosystems.

Grassland ecosystems have suffered intense modification worldwide, resulting in a loss of biodiversity. Birds that breed in grasslands have experienced steep population declines over recent decades. When modifications of grasslands reduce the available breeding habitat, birds may select habitat features that do not favor their breeding success. However, the relationship between selected nesting habitat and nest survival is not well established for many grassland birds. We studied the nest site selection and nest survival of a common grassland bird, the Grassland Yellow-Finch Sicalis luteola, in the Flooding Pampa of Argentina, a region comprised mostly of large natural rangelands. We searched for nests over three breeding seasons (2017–2020) and used linear models to analyze whether finches selected nest sites according to distance from grassland edges, type of grassland community, vegetation density, visual concealment, and grass height. We modeled daily nest survival rates (DSR) to assess whether these variables influenced breeding success. We confirmed the fate of 133 nests, of which 93 (70%) failed, predation being the principal cause (84% of failures). Our models showed that finches selected shrubby grasslands over other types available, and sites with high overhead visual concealment. Only overhead concealment was positively correlated with DSR. This may indicate that their nests are affected by avian predators that search for prey from above and that they benefit from tall and dense vegetation that provides good overhead cover. We believe that preserving areas of heterogeneous and dense shrubby grasslands within grazing plots is a good starting point that could benefit this bird species and others with similar nesting strategies.

Human-carnivore conflicts arising from livestock depredation can impact both livestock producers and carnivore populations. We used livestock depredation insurance claims from 2 895 depredation events involving 7 411 livestock throughout Mexico to evaluate the diversity of carnivores and livestock involved in depredations and identify attributes related to species-specific livestock depredation sites and carnivore predation patterns. Cattle comprised 48% of depredation events, followed by sheep (36%), goats (13%), equids (2%), and hogs (< 1%). Coyotes were responsible for 28% of depredation events, followed by domestic dogs (27%), pumas (22%), jaguars (15%), and bears (5%). Both kill sites of differing livestock species and predation patterns of carnivores varied with respect to predator responsible or prey killed, landscape attributes, and season; patterns reflected primarily species-specific habitat preferences, livestock husbandry practices, and tolerances of carnivores for human impacts. Our results indicate that the greatest challenge of managing depredation conflicts in Mexico is that depredations by carnivores that kill the most livestock (coyote, domestic dog) are facilitated by increasing human impacts and the canid's adaptability. Depredations associated with carnivores limited to relatively rare ecological conditions (e.g., proximity to protected natural areas [PNAs]) can be mitigated by cultural changes, such as avoiding establishing new livestock production areas near PNAs, or new PNAs adjacent to traditional livestock production areas. Opportunities to limit ecologically and sociologically problematic impacts such as retaliatory killing of carnivores include accurate identification of the actual depredating carnivore.

Ecological resources sustain life, influencing ecology and landscape but demanding sustenance. Urbanization is impacting such resources, which is a critical concern for stakeholders. However, appreciating green infrastructure (ecological resources) is relative as the resourceful and resource-deficient nourish divergent views. Socioeconomic determinants significantly influence urban environmental integrity, making their study cardinal. This study evaluated the empirical information for holistic appraisals. The data were obtained from planned (Faisalabad) and semi-planned (Jhang) cities through a cross-sectional survey using a structured questionnaire from 250 households. These two cities were selected because they are physically and economically homogenous but have divergent urbanization trends. Findings construe 48.6% perceiving the environment as unhealthy. About 97.6% understood urban ecological degradation, showing concern. The statistical inferences based on Kruskal–Wallis and Wilcoxon rank-sum tests rendered that age, education, profession, and nature of job influence (P ≤ 0.05) awareness regarding urban-ecological resilience. In contrast, gender, duration of stay, and income were insignificant. However, 64.6% showed an inclination for active participation. Contrarily, the majority complained about the city administration. The meagerness of female participation was noticeable, demanding redressal. An enhanced focus on the younger segments of urban society is also needed. Conclusions render that all stakeholders must join hands for urban ecological resilience.

Vegetation net primary productivity (NPP) plays a crucial role in assessing the quality and function of terrestrial ecosystems. The Qilian Mountains (QLM) are an important ecological barrier and water conservation area in northwest China. However, the driving factors of the NPP change in the greening (NPP increased) area and browning (NPP decreased) area of QLM remain unclear. This study analyzes the spatiotemporal dynamics and driving factors of NPP in QLM over the past two decades by utilizing hydrometeorological data and human activity (HA) data. Employing spatial and trend analyses to explore the variation of NPP. Additionally, the gravity model was introduced to track the migration of NPP's gravity center, and the Geodetector model was employed to identify the driving factors and their interactive impacts on NPP change. Finally, the Hurst index was used to predict the persistence of the changing trend. Results reveal a fluctuating increasing NPP trend (2.38 gC m⁻² a⁻¹) in QLM from 2000 to 2020, with cultivated vegetation and broad-leaved forests showing greater increases. Approximately 75.37% of QLM pixels display increased NPP trends, primarily located in the southeastern regions. The NPP gravity center shifted northwestward by 18.24 km. Spatially, high NPP values cluster concentrated in the southeast, while low values cluster concentrated in the northwest. In the greening area, precipitation, vapor pressure deficit, and evapotranspiration dominate NPP changes, contributing 46.1%, 31.5%, and 25.0%, respectively. In the browning area, soil moisture, HA, and precipitation were the primary factors driving NPP change with contributions of 8.4%, 7.6%, and 6.6%, respectively. The results of the Geodetector model indicated that the explanatory power of a single factor was nonlinearly enhanced when it interacted with other factors. The Hurst index suggests that the NPP change was not persistent, showing clear reverse persistent characteristics, which implies uncertainty of the vegetation change in QLM. These findings reveal nonlinear responses of NPP to climate change and human activities in the context of global warming, providing insights for QLM's ecological protection and sustainable development.

Rangelands cover half of the world's land surface, yet they are often threatened by multiple factors, such as the encroachment of woody plant populations. This comprehensive review investigates the fusion of ecohydrology, remote sensing, and modeling approaches to tackle this global issue. We discuss the consequences of woody plant encroachment (WPE) and consider effective strategies for preventing or mitigating encroachment in rangeland ecosystems. We highlight the importance of understanding the complex interactions between biotic and abiotic factors that accelerate these processes and the need for interdisciplinary approaches to address this issue. We also identify a range of challenges intrinsic to WPE management, including the need for deeper insights into the catalysts of WPE and their impacts on ecohydrological connectivity across diverse ecosystems. This review also emphasizes the role of remote sensing in monitoring WPE and the potential of modeling approaches to inform management decisions. We highlight the significance of comprehending regional nuances, and the influences of climate change, and encourage the development of strategies to improve collaboration among stakeholders engaged in management initiatives. We also reiterate the necessity of integrating the human dimension, including policy formulation and landowner perspectives, into effective WPE management and restoration projects. We advocate for a holistic, integrated approach to shaping the future of rangeland management in an ever-evolving global landscape.

Spring and summer rainfall patterns in Mongolian semi-arid grazing lands vary greatly from year to year, and are thought to affect the energy balance and nutritional conditions of sheep via plant community changes. To test this, climatic and vegetation data in Mongolian semiarid grasslands were obtained from spring to summer over 3 yr. For 2 yr, sheep energy intake and expenditure were calculated, and the energy balance and nutrition indicators were compared among years with different seasonal rainfall patterns. In 2019 and 2022, rainfall patterns were characterized by the presence and absence of early summer drought, respectively. Compared to 2019, plants were tall and abundant in 2022; thus, the mean bite size, energy intake, and body weight were higher. Estimated energy intake and expenditure were 4.56 and 2.10 Mcal in 2019, and 6.75 and 1.63 Mcal in 2022, respectively, indicating that rainfall timing and amount affected vegetation assemblage, plant height, herbage nutrition, grazing behavior, animal energy balance, and nutrition conditions. Insufficient rainfall before early summer in semiarid grazing lands resulted in low energy intake and balance, and delayed body weight gain could not be recovered. These results can inform the management of grazing lands to ensure optimal livestock conditions.

Management of grasslands for agriculture and other land uses is a critical issue for the conservation of grassland animals, both due to direct effects on mortality, as well as indirect effects such as altered predation regimes. In this study, we investigated the effect of mowing on the predation pressure by birds on an endangered snake, the Hungarian meadow viper (Vipera ursinii rakosiensis), using plasticine snake models. We placed 200 snake models each in mowed hayfields and grazed pastures (as controls) in two study periods, before and after mowing on hayfields, in 2021 and 2022. We found no strong negative effects of mowing on attack rates by birds in our study. Attack rates on snake models were higher before mowing than after mowing, and in general lower in the second year of the study than in 2021. However, in 2021 attack rates on snake models in pastures were higher than on hayfields, but this pattern reversed in 2022, when attacks were more frequent on hayfields than pastures. Our study highlights the importance of considering potential factors influencing predation pressure and predator-prey dynamics in grassland habitats, as well as the need for further research to provide results for evidence-based conservation management strategies to mitigate population declines and local extinction risk.

Rangeland ecosystems, and their managers, face the growing urgency of climate change impacts. Researchers are therefore seeking integrative social-ecological frameworks that can enhance adaptation by managers to these climate change dynamics through tighter linkages among multiple scientific disciplines and manager contexts. Social-ecological framings, including resilience and vulnerability, are popular in such efforts, but their potential to inform meaningful rangeland adaptation science is limited by traditional disciplinary silos. Here, we provide reflective lessons learned from a multidisciplinary Rangelands, Ranching, and Resilience (R3) project on U.S. western rangelands that addressed 1) biophysical science projections of forage production under future climate scenarios, 2) ranchers’ views of resilience using social science methods, and 3) outreach efforts coordinated through extension professionals. Despite the project's initial intentions, human dimensions and ecological researchers largely worked in parallel sub-teams during the project, rather than weaving their expertise together with managers. The R3 project was multidisciplinary, but it provides a case study on lessons learned to suggest how social and ecological researchers can move towards approaches that transcend individual disciplines. Transdisciplinary science and management in rangelands requires more than just conceptual social-ecological frameworks. Additional methodological concepts need to include: 1) relationship building; 2) shared meaning making; and 3) a commitment to continual conversations and learning, or staying with the trouble, following Haraway (2016). If the goal is to address meaningful rangeland adaptation science rather than just produce academic products, researchers, outreach professionals, and rangeland-based communities should address a series of critical troubling questions. In the process of addressing these, deeper engagement among and beyond disciplines will occur as relationship building, shared meaning, and continual conversations and learning facilitate staying with the trouble.