The exotic annual grass ventenata (Ventenata dubia L.) is raising concern as it rapidly invades multiple ecosystem types within the United States, including sagebrush steppe, ponderosa pine forests, woodlands, and much of the Palouse and Pacific Northwest Bunchgrass Prairie (PNB). Despite increasing attention, little is known about the invasion dynamics of ventenata, especially its response to disturbances such as grazing and fire. In this study, we examined how cattle grazing and prescribed fire affect the abundance (standing crop, cover, frequency, and density) of ventenata and other plant groups on the PNB over time using two separate long-term studies established in 2004. The first study (Cattle Grazing) looked at the 14-yr effect of cattle grazing exclusion on ventenata aboveground biomass and cover. Our second study (Grazing and Prescribed Fire) examined main and interactive effects of cattle exclusion and prescribed fire on ventenata over three sampling periods (2008, 2016, and 2018). We documented a 30% increase in ventenata cover and 55% increase in frequency on the PNB over the past 15 yr, including areas that were not disturbed by fire or cattle grazing. We found only weak evidence that cattle grazing increased ventenata standing crop when compared with cattle-excluded paddocks, something that could be related to timing of use. There was no evidence that prescribed burning impacted the response of ventenata on its own. However, we found some evidence of interactions between cattle grazing and prescribed fire that suggests prescribed burning could help reduce the abundance of ventenata in areas grazed by livestock. These studies reinforce the important differences between ventenata and other invasive winter annuals in grasslands and clarify a need for research that focuses primarily on the dynamics between this relatively new exotic species in grasslands and the many ecosystems it now inhabits.

Rangelands account for a large portion of global carbon stocks and have high potential for carbon sequestration if managed properly. Grazing has variable effects on soil organic carbon depending on climate, geography, and soil type; therefore, grazers in various regions may need to be managed differently to ensure optimum carbon sequestration. This study aimed to assess the impacts of cattle grazing on soil carbon in seminatural subtropical humid rangelands in Florida. We measured root biomass, bulk density, soil organic carbon (SOC), and total carbon (TC) concentrations and used the equivalent soil mass method to assess organic carbon stock (OCS) and total carbon stock at three depths (0–5 cm, 5–15 cm, and 15–30 cm) inside and outside of five 15-yr-old grazing exclosures. We also surveyed the vegetation at each sampling location and litter biomass inside and outside of exclosures. We found that grazing increased bulk density, decreased root biomass, but did not affect litter amount. SOC and TC concentrations did not differ significantly between ungrazed and grazed plots. On an equivalent soil mass basis, we found greater soil carbon stocks in grazed plots within the shallower part of the soil (0–5 cm). Removal of grazing resulted in a clear difference in vegetation composition between grazed and ungrazed plots, with grazed plots having higher grass cover (on average 60% in grazed vs. 13% in ungrazed) and ungrazed having higher forb cover (on average 78% in ungrazed vs. 32% in grazed). Results provide evidence that grazing increased soil carbon stocks in the top layer of soil, but longer-term studies are needed to assess the impact of grazing on SOC concentrations. To further clarify the impact of grazing on drivers of soil carbon in subtropical humid seminatural grasslands, we recommend further study of grazing impacts on productivity, root production and turnover, and microbial responses.

As human activities alter winter climates and disturbance regimes in grassland and rangeland ecosystems, the temperatures that plants experience during spring are changing. Litter can help buffer overwintering herbaceous plants from temperature fluctuations, and management practices dictate whether litter is present during the winter. Here, we investigate how disturbance type (burning, mowing) and timing (spring, fall) affect leaf characteristics related to growth and stress tolerance and how these traits change over time for five common tallgrass prairie species including four forb (Monarda fistulosa, Ratibida pinnata, Silphium integrifolium, Symphiotrichum laeve) and one grass species (Bromus inermis). To do this, we established a field experiment in Wisconsin, where plots were annually burned in the fall, mowed in the fall, burned in the spring, or left undisturbed (control) for 3 yr. We sampled leaves of target species seven times from spring emergence through early summer to measure specific leaf area (SLA) and leaf cold tolerance in each treatment. Leaves from fall-burned plots had lower SLAs, while leaves in spring-burned plots had higher SLAs early in the growing season. Leaf cold tolerance was similar across most treatments except in spring-burn plots, where leaves became more cold-hardy through time. We found weak evidence of a tradeoff between leaf growth and both cold tolerance and SLA. These results suggest that management decisions like litter removal before winter (e.g., fall burn or mow) prompted different plant responses compared with plots where litter was present during winter (e.g., spring burn). As species respond to winter climate change, management decisions have implications for mitigating climate change impacts and maintaining diversity in grasslands by affecting early-season plant growth strategies. For example, removing litter in the fall by burning promotes stress-tolerant responses, which may better equip plants to tolerate changing spring conditions.

Postfire restoration of sagebrush steppe is limited by poor sagebrush establishment from seed. Transplanting may improve seedling establishment, but it requires more labor and expense. Given variable transplant survival in big sagebrush (Artemisia tridentata Nutt.), establishing links between restoration practices and survival related to exposure to adverse weather, via plant response to stress, could significantly improve transplant efficacy. We tested how planting season and transplant age (size), two restoration practices likely to affect seedling survival across a range of environmental conditions, related to transplant survival and stomatal conductance, an indicator of seedling ecophysiological performance. We found low mean stomatal conductance during key periods in spring and early summer was associated with subsequent growing season mortality across all size-classes. Overall, these findings suggest managers should consider the importance of plant performance during key stressful periods in evaluating transplant survival related to restoration methods.

Trees play an important role in livestock grazing lands, but the effect of tree shade on grass productivity has not been studied widely. In this study, we evaluated the effect of tree shade on grass yield in pasturelands with dispersed trees in the humid tropics of Mexico. We sampled two livestock grazing systems: 1) scattered native trees in paddocks composed of Cordia alliodora and Cedrela odorata trees with Brachiaria brizantha cv. ‘Xaráes’ grass; and 2) scattered trees in paddocks composed of C. alliodora, C. odorata, and Guazuma ulmifolia, with B. brizantha cv. ‘Marandú’ grass. We established isolation cages at different distances from trees: 1) under the tree canopy, 2) on the border of the tree canopy, and 3) out of reach of the tree canopy, to measure grass yield, grass height, dry matter content, and senescent biomass from April to September. The effect of tree shade on grass yield was significant, with the highest grass production under the tree canopy compared with grasses that grew on the border of the tree canopy and in full sun. We found the highest forage yield in June for B. brizantha cv. Xaráes and the lowest yield in September for the same grass. During July and August, B. brizantha cv. Xaráes yielded the greatest average height, with the lowest values during April and May for B. brizantha cv. Marandú. The greatest dry matter content was recorded in September for B. brizantha cv. Xaráes. Additionally, the most senescent mass was recorded in June and the lowest in April for the same grass. Native trees that persist in grasslands positively influence forage yield during the dry season. Increasing the productivity of the grasslands by agroforestry practices may represent a valuable alternative to mitigate the negative effects of deforestation caused by extensive livestock farming.

Abiotic environmental factors have a major impact on the distribution and performance of plant species. For this purpose, regarding the importance of Vicia variabilis in forage production and the possibility of using it in the improvement and reclamation of oak forest understory, this study aimed to investigate the effect of soil variables and topography on the response of this species using generalized additive models in the west of Iran. The results showed that the response pattern of V. variabilis along the gradient of clay, silt, and soil saturation moisture followed the monotonic increase model. Conversely, the response of this species along the gradient of sand percentage, bare soil percentage, and content of sulfate salts in the soil followed the monotonic decrease model. The species response pattern along the gradients of electrical conductivity, lime percentage, pH of soil, soil sodium ion, phosphorus, altitude, slope, stone and gravel percentage, and canopy cover percentage of the forest overstorey followed a unimodal model, and its optimal growth limit for these factors was 0.85 dsm^–1, 5.10%, 7.26, 0.38 meql^–1, 35 ppm, 1 650 m, 31%, 7%, and 25%, respectively. The results of phenological studies on V. variabilis during 2018 to 2020 showed that late June/early July was the most suitable time for livestock use of this species, and the best time to collect the seeds was mid-July to the early August. Regarding the response of this plant to the gradient of studied environmental factors, it is recommended to pay attention to its habitat characteristics and ecological requirements in improvement programs on oak forests understory vegetation.

The conversion of rangelands to other land uses generates many negative environmental side effects and increases the vulnerability of pastoralists' livelihoods. In this regard, it would be important to predict the future land use changes and to understand the pastoralists' knowledge, attitude, and behavior toward the rangelands' conservation and sustainable management. In this study, the land use changes of Iran Kishlak pastoralist settlements were initially predicted using the Markov chain model and the vulnerability of the study area was determined using the fuzzy analytic hierarchy process in terms of environmental stresses during various years. Also, to explore the rangeland conservation behaviors of pastoralists, the theory of planned behavior (TPB) was employed. The results indicated that continuation of the current trend of land use change would lead to the intensification of environmental vulnerability, as well as further reduction of rangeland, forest, and water body area. The results of estimating the TPB model revealed that the attitude, subjective norms, and perceived behavioral control could account for 75% of the variance changes in the pastoralists' intention toward rangeland conservation. Compared with the perceived behavioral control, the intention toward rangeland conservation had a stronger effect on rangeland conservation behavior. On the basis of the findings of this study, we concluded that to analyze the pastoralists' rangelands conservation behaviors, the use of TBP can be the first step toward preventing the degradation of vegetation and sustainable management rangelands. Accordingly, it is recommended that pastoralists be provided with technical and economic assistance in the field of rangeland conservation strategies. This can improve their attitude and beliefs and consequently rangeland conservation behavior.

Climate change has increased the frequency and severity of frequent drought in the Kenya arid and semiarid lands with resultant fodder and water shortages. In order to adapt to these longer and less predictable droughts, keeping of camels has been adopted as a coping strategy in grappling with the vagaries of climate change. Camels are both grazers and browsers of a broad spectrum of preferred forages whose nutrient composition is not well documented. The objective of this study was to identify and determine the chemical composition of forage species mostly preferred by lactating Somali camels in Laikipia County, Kenya. Lactating Somali camels and their calves were monitored while browsing and grazing in the rangelands during the wet and dry seasons from August to November 2019. The forage species were ranked on the basis of bite count. The most browsed forages identified through observation were sampled, identified by the local and scientific names, and analyzed for proximate composition, detergent fiber fractions, and in vitro dry matter digestibility. The most browsed forage species were Acacia nubica (22.6%), Acacia seyal (47.3%), Cucumis aculeatus (7.2%), Euclea divinorum (11.1%), Hibiscus parrifolia (11.9%) during the wet season and Barleria acanthoides (22.9%), Balanites aegyptiaca (15.5%), Cynodon dactylon (11.7%), Lycium europaeum (32%), and Pollichia campestris (17.8%) during the dry season. Shrubs constituted 60%, trees 30%, and grasses 10% of the most preferred forage species. The preferred browsed and grazed species had a range of 7.1% ± 0.4% to 25.7% ± 1.2% crude protein on a dry matter basis, 29.1% ± 2.7% to 74.0% ± 7% for neutral detergent fiber concentrations, and 43.4% ± 0.2% to 81.6% ± 0.3% for in vitro dry matter digestibility. The study indicates that trees and shrubs with high crude protein and low neutral detergent fiber concentrations were more preferred, indicating that forage nutritive value affected the forage preference by the camels.

Coverage of living (green) vegetation influences rangeland processes and biodiversity but remains a challenge to quantify at small spatial grain. We describe a technique for rapid airborne (unmanned aerial vehicle) measurements of continuous spatial coverage of living vegetation at a resolution (spatial grain) of 8 cm ground sampling distance. We then applied this technique at the pasture (paddock) scale (tens of hectares) in two contrasting grassland ecosystems (semiarid shortgrass steppe in northeastern Colorado, United States and mesic grassland in central Texas, United States) to determine effects of locally relevant grazing treatments on spatial variability and dependence (pattern) in fractional coverage of green vegetation (fractional vegetation cover; FVC). Site-specific regression models developed using reflectance in visible and near-infrared wavebands explained 90% and 89% of variance in FVC for semiarid and mesic grassland, respectively. Mean FVC was similar among shortgrass steppe pastures differing in grazing treatment (light or heavy grazing by cattle, moderate cattle grazing with prairie dogs present). In contrast, FVC was lower with rotational compared with continuous, year-long grazing in the mesic grassland. Heavy grazing in shortgrass steppe and rotational grazing in mesic grassland increased the spatial uniformity in FVC by reducing spatial variability and increasing spatial dependence in FVC, the latter by increasing the similarity in FVC values among spatially separated patches. Unmanned aerial vehicle–enabled remote sensing provides for FVC at sufficiently small spatial grain to characterize spatial variation in FVC at the pasture scale. Results can be used to evaluate the effectiveness of management actions intended to alter spatial variation in FVC to achieve conservation or diversity objectives. Enhanced capacity to monitor FVC at small spatial grain promotes adaptive management of grasslands.

Wet grasslands are an important element of rangeland communities around the world and are key in the provision of many ecosystem services, including interception of runoff, filtration of pollutants, storage of carbon, and maintenance of wildlife habitat. In the northern Great Plains, wet grasslands are often more productive than upland grasslands and are an important source of seasonal forage or hay. As climates continue to limit growing conditions and yields of upland forages, grazing pressure on wet grasslands may increase. Our research focused on a wet meadow rangeland in Manitoba, Canada to test how the timing and intensity of grazing affect the composition, diversity, and function of plants and soils. Our results demonstrate that the effects of grazing on wet meadow grasslands depend on its timing and intensity. Early grazing shifted the composition of plants, increasing the abundance of weedy and invasive species, including foxtail barley (Hordeum jubatum). The effect of grazing on plant diversity also depended on its intensity. As a result, the spatial heterogeneity of wet grasslands increased following early, intense grazing but decreased following late-season grazing. Although the effect of grazing on a number of soil variables did not differ among grazing treatments, early, intense grazing increased soil bulk density. Our results demonstrate that late-season, moderate-intensity grazing can sustain the diversity and function of wet meadow grasslands. Our research also highlights the negative impacts of early-season, intense grazing on the proliferation of weedy and invasive plants. As changing climates across the Great Plains continue to increase grazing pressure on marginal rangelands, adaptive management must focus on increasing the resilience of wet grasslands. Our work points to an important gap in our understanding of interactions among grazing, ecosystem services, and belowground production in wet meadow grasslands.

Management for invasive species is usually done with the intent of maintaining or enhancing one or several ecosystem services. On rangeland landscapes, management is often focused on provisioning services (e.g., livestock) but can also include maintaining biodiversity. Rangeland landscapes are often large and complex, suggesting understanding the invasion and management efforts is best done at multiple scales. The objective of this study was to assess the effectiveness of sericea lespedeza (Lespedeza cuneata [Dum.-Cours] G. Don) management practices on two study areas that were focused on managing livestock and promoting biodiversity simultaneously. At one study area, an experiment containing 134 different prescribed fires was evaluated for 19 yrs comparing pyric herbivory with traditional rangeland management with fire and grazing on sericea lespedeza invasion. The second area had a 21-yr observational study across 16 000 ha with 541 different prescribed burns and on the effects of pyric herbivory and herbicide applications on sericea lespedeza. We found support that pyric herbivory with cattle (Bos spp.) or bison (Bos bison) contributed to long-term invasion mitigation for sericea lespedeza, whereas we found no support that other management practices added to the mitigation provided by pyric herbivory. We found no support for a season of fire effect and/or herbicide control. These practices only provided short-term sericea management (1 yr). Pyric herbivory remains the only viable management action that can reduce the rate of invasion and use this invasive forage legume for livestock production at actual management scales. This study demonstrates the importance of developing large-scale studies of realistic treatments that integrate practices such as fire, grazing, and herbicides to understand the effects of invasion and control efforts on rangelands with multiple objectives.