Rangeland Ecology & Management最新文献

In response to the challenge of simultaneously controlling invasive plant species and restoring desired species, seed technologies have been developed that use activated carbon to protect desired plants from pre-emergent herbicides that target invasive plants, such as herbicide protection pellets (HPPs). One ecosystem imperiled by this challenge is the sagebrush steppe of the Western United States. Land managers in the sagebrush steppe may use consecutive or concurrent applications of different pre-emergent herbicides in order to control invasive annual grasses while restoring desirable perennial vegetation that helps stabilize soil and reduce the frequency of wildfires. We conducted a pot study looking at the efficacy of HPPs for six perennial species with novel herbicide practices used by land managers: an application of both imazapic and indaziflam. The six test species included four bunchgrasses, one shrub, and one forb. The bunchgrass species responded well to the HPPs with similar seedling counts and biomass to bare seed when herbicide was not applied and higher seedling counts and biomass than bare seed when a double herbicide treatment was applied. Our results demonstrate that broader testing of HPPs with the application of both indaziflam and imazapic is needed, especially across wide climoedaphic field conditions.

Sustainable beef production is a growing concern worldwide, particularly in arid regions where limited natural resources availability and adverse environmental conditions pose significant challenges. This manuscript presents a comprehensive review of the potential of Criollo cattle breeds as an alternative for sustainable beef production in America. Criollo cattle, known for their resilience, hardiness, and adaptability to arid and semiarid environments, offer unique advantages in sustainable livestock production systems. Therefore, the use of criollo cattle and their crossbreds may be an alternative to face current and emerging challenges in beef production, which include a decrease in rangelands carrying capacity, adaptation to adverse environmental conditions, increase in diseases and parasites due to climate change, and diminished regional feed and forage production. This manuscript discusses the environmental sustainability of Criollo cattle production, including resource use efficiency, carbon footprint, and land management practices, providing insights into the potential ecological and economic benefits of these breeds. Also, it highlights the role of Criollo cattle in assisting organic and grass-fed beef producers in producing high-quality products using primarily forage-based diets. This approach can significantly enhance their organic or grass-fed certification. Criollo cattle have a unique flavor profile, which is highly sought after by consumers of organic and grass-fed beef. The meat of Criollo cattle produces omega-3, linoleic, and other fatty acids, which are beneficial to human health. Criollo cattle breeds are a valuable resource for enhancing resilience, promoting local biodiversity, producing good quality meat, and contributing to sustainable beef production in America.

Wildfire is an increasing concern throughout the world, with wildfires increasing in size, frequency, suppression cost, and loss of lives and resources. Targeted grazing has been suggested as a tool to establish and maintain strategic fuel breaks by reducing the fine herbaceous fuel load and subsequently fire behavior metrics. In a full factorial replicated experimental design, we evaluated the effect of domestic cattle grazing at two seasons (summer and fall) and two utilization levels (low and moderate) on fuel characteristics and fire behavior metrics in two big sagebrush (Artemisia tridentata Nutt.) communities. Shrub cover and herbaceous biomass before and after grazing were estimated in 2014 and 2015. Grazed and control plots were burned in late September 2015 under low fuel moisture conditions; flame height and fire rate of spread were measured. Cattle grazing reduced the herbaceous fuel load and grass height and increased herbaceous litter cover on the soil surface following the short-term grazing treatments. The more intensely plots were grazed also resulted in lower fuel loads than less intensely grazed plots. The season of grazing did not affect herbaceous fuel loads at the time of prescribed fire because utilization of grasses and forbs varied by season resulting in similar herbaceous biomass among both seasons of grazing at the time of the prescribed fire. Grazing was found to be an effective tool at altering herbaceous wildland fuels, which reduced fire behavior metrics when shrub cover was below 18%. Flame height was positively correlated with the amount of herbaceous vegetation, grass height, and annual grasses in the plant community at low shrub cover. However, at higher shrub canopy cover (>18%), cattle grazing for fuel reduction and alteration was limited due to low herbaceous biomass and the wildfire's potential to carry through the shrub canopy.

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.