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Collaborative adaptive management (CAM) is hypothesized to benefit management of rangeland ecosystems, but the presumed benefits have seldom been quantified, and never in a multipaddock rotational grazing system. Here, we evaluated average daily weight gain (ADG) of livestock (kg steer–1 d–1) in four grazing management treatments during the summers of 2016–2018 in a semiarid shortgrass steppe. These four treatments had the same stocking rate but differed in stocking densities. The three lowest stocking densities were implemented using nonadaptive grazing management, while the highest stocking density was implemented using CAM by an 11-member Stakeholder Group. Three of the four treatments used multipaddock rotational grazing. Growing season precipitation varied from drought in 2016 to near average in 2017 and dry in 2018. During nondrought years, ADG under nonadaptive grazing declined linearly as stocking density increased from low to high. This relationship was not significant during drought (2016). CAM increased absolute livestock production by 0.13 to 0.19 kg steer–1 d–1 in nondrought years, or a 23–25% relative increase in ADG. This benefit of CAM arose from the Stakeholder Group's ability to rotate cattle in response to spatiotemporal heterogeneity across the landscape—i.e., the ability to graze the “right pastures at the right time.” Multiplying the additional grazing season livestock gains achieved through CAM by the monetary value of gains ($ kg–1) resulted in an estimated additional gross revenue return from CAM of $48.16 to $55.54 per steer annually, as compared with revenues from nonadaptive multipaddock rotational grazing under nondrought conditions. These results indicate that CAM, supported with substantial and timely monitoring data, can minimize decreases in livestock production associated with high stocking densities used in multipaddock rotation systems. However, in this experimental context, the economic benefits of increased livestock production associated with CAM were likely insufficient to offset the substantial cost of this approach.
Shrub cover in alpine meadows around the world has experienced significant changes during the past 20 yr. An increase in shrub cover has often been associated with large influences in ecosystem functions. The objectives of the present study were to investigate the impact of shrub cover on herbaceous forage quality and yak grazing efficiency on the Qinghai-Tibetan Plateau, China. Forty-eight yak steers were randomly assigned to four grazing pastures with different shrub cover rates (control, low, middle, and high). The whole grazing period was categorized as vegetative stage (June to July), bloom stage (August to October), and senescent stage (November to December). Herbaceous forage chemical composition and body weight of yaks were measured, and serum and rumen samples were analyzed. Although shrub cover had no effect on herbaceous forage chemical composition and serum biochemical parameters of yaks, total herbaceous forage production in pastures and crude protein intake of yaks decreased with increasing shrub cover. Such changes decreased average daily gain of yaks. As expected, increasing the herbaceous forage maturation significantly decreased crude protein content while increased dry matter, neutral detergent fiber and acid detergent fiber contents, consequently, reduced herbaceous forage crude protein and organic matter intakes and average daily gain of yaks. The rumen of yaks has higher ammonia nitrogen and total volatile fatty acid concentrations and butyrate proportion in the bloom stage of forage compared with those of the senescent stage. The results indicate that shrub cover on the Qinghai-Tibetan Plateau needs a certain level of control for the sustainable grazing yak production, although it has little negative effect on blood health and rumen fermentation. Additionally, it is vital to select the optimum time to market livestock or supplement feed with yaks during the cold season on the Qinghai-Tibetan Plateau.
Concern about the impacts of two invasive annual brome grasses (cheatgrass and Japanese brome, Bromus tectorum L. and B. japonicus Thunb. ex Murray) on the mixed-grass prairie of North America's northern Great Plains (NGP) is growing. Cheatgrass is well known west of the NGP, where replacement of fire-intolerant, native sagebrush steppe by fire-prone, exotic annual grasslands is widespread. Consequently, fire is often not considered as a tool for controlling annual bromes. This should not be the case in the NGP, where mixed-grass prairie is adapted to frequent fires. Fire's efficacy may vary with the degree of invasion, though; suppressing postfire annual brome populations or enhancing the native plant community may improve postfire annual brome control in highly invaded areas. To test this, we performed an experiment at two sites to evaluate the relative effectiveness of prescribed fire alone, fire followed by imazapic application and fire followed by native seeding across a pretreatment invasion gradient of annual brome-to-native species cover ranging from 0.05 to 2.35. Fall-prescribed fire alone greatly reduced annual bromes, but by the second yr after treatment the effect was significant only at invasion ratios < 1.2. Postfire imazapic application reduced annual bromes even further than fire alone, but only for 1 yr at the less invaded site and only at invasion ratios > 1.2 in yr 2 at the other site. Native species cover and total species richness responded positively to all treatments, but the degree of their response varied along the invasion gradient, between sites, with time since treatment and among treatments. Also, at one site, fire yielded a lagged stimulation of short-lived, exotic forbs. Seeding had little effect. Fire is an effective tool for reducing annual bromes in the NGP at lower invasion levels, but more tools are needed for long-term, effective control at highly invaded sites.
Dissolved solids can negatively impact livestock drinking water. To characterize dissolved solid concentrations in the northern Great Plains, we studied 45 water sources over 11 yr. Ca, F, Mg, Na, and total solids sometimes exceeded recommended levels but rarely reached levels empirically shown to negatively impact livestock. Fe often attained concentrations that reduce water consumption, which can reduce feed intake and weight gain. Excessive Fe was likeliest in creeks and reservoirs. SO4 sometimes reached concentrations that reduce weight gain but rarely reached concentrations causing health problems. Excessive SO4 was least likely in reservoirs. A safeguard against water quality problems is ensuring livestock can access multiple water source types (e.g., wells and reservoirs) so that they can use taste and smell to choose acceptable water. Where this is impossible, water quality monitoring is of greater importance. Inexpensive electrical conductivity meters roughly estimate water quality and can identify watering locations requiring more detailed monitoring.
Ventenata (Ventenata dubia L.) is an invasive annual grass that has rapidly expanded its range across temperate grassland and shrub-steppe ecosystems in western North America. However, there is little published regarding its ecology, especially its relationship with fire on rangelands. The objective of this study was to examine the effect of fire on ventenata invasion in the Pacific Northwest Bunchgrass (PNB) Prairie. Given the influence of fire on the invasion of other annual grasses such as cheatgrass (Bromus tectorum L.), we expected that fire would facilitate the spread and increase in abundance of ventenata. In addition, we considered that annual variation in precipitation might mask the effect of fire and drive the year-to-year variation in production of ventenata. Therefore, we resampled 56 plots in 2015 and 2016 where frequency and foliar cover of ventenata had been recorded in 2008 and where 12 of these plots had burned in the past 15 yr. We then compared ventenata abundance (frequency and foliar cover) between burned and unburned plots within each sampling yr (2008, 2015, and 2016), as well as the change in abundance over time. Our data revealed that ventenata frequency and cover increased on all plots. However, there was not significantly higher abundance in burned plots in any of the sampling years. In addition, ventenata abundance did not increase more in burned plots over time. Our findings suggest that, unlike cheatgrass, fire may not be a driving factor in the spread and increase of ventenata across the PNB Prairie. This finding has important implications for the management and control of ventenata, as well as the conservation of the PNB Prairie.
Rangelands provide ecosystem services that are economically and ecologically critical for humans. Globally, invasion of exotic grasses drives loss of biodiversity and resilience of rangelands. In South Texas, buffelgrass (Cenchrus ciliaris syn. Pennisetum ciliare [L.] Link), a C4 perennial grass, was brought from Africa for range improvement as early as the 1930s. Buffelgrass generally increases forage biomass for livestock yet reduces habitat suitability for wildlife. Interest in controlling buffelgrass has increased due to its negative impacts on iconic wildlife, such as whitetailed deer (Odocoileus virginianus, Zimmermann 1780) and northern bobwhite (Colinus virginianus, Linnaeus 1758). The objective of this study was to evaluate the effect of a targeted grazing strategy that used buffelgrass and plant community phenology as indicators to determine the timing of cattle movement. On two private ranches in different ecoregions, we tracked targeted grazing versus light grazing in native-dominated and buffelgrass-dominated plant communities across variable precipitation through five growing seasons. We measured the effects of grazing type, plant community type, and precipitation on buffelgrass cover, native plant species richness, foliar cover, and Shannon diversity. Targeted grazing had a strong impact on diversity, increasing 0.37 ± 0.07 from a mean of H = 1.29 under the targeted grazing management. Conversely, buffelgrass cover was negatively correlated with Shannon diversity, decreasing it by 0.075 ± 0.03 for every 10% increase in buffelgrass cover from a mean of H = 1.29. Despite a variability in precipitation across seasons and years (93–455 mm), targeted grazing improved species richness and cover of native plants throughout the study. Our findings suggest that targeted grazing shows promise as an adaptive grazing strategy that reduces the impact of buffelgrass across highly variable precipitation. In unpredictable environments, management techniques that improve the resilience of plant communities through preserving biodiversity are critical.
The rugged Himalayan landscape results in large variations in site conditions that regulate plant response to warming. There is lack of deeper understanding on plant response to warming under differing site characteristics in the mountainous terrain. A 2-yr experiment was conducted in the high mountains of Bhutan. The objective was to investigate the effects of short-term artificial warming on high-altitude grassland vegetation at north- and south-facing sites. An artificially warmed environment was simulated using open-top chambers (OTCs) that were compared with control chambers experiencing ambient conditions. Variables measured were species diversity, species richness, proportions of plant functional groups, forage dry matter, and forage quality. Generally at the north-facing site, OTC treatment showed a lower species diversity (OTC treatment H' ≈2.35; Control treatment H' ≈2.75), species richness (OTC treatment MI ≈1.38; Control treatment MI ≈1.45), sedge abundance (OTC treatment sedge cover ≈14.5%; Control treatment sedge cover ≈25%), and crude protein content (OTC treatment CP ≈6.60%; Control treatment CP ≈7.70%). On both sites, OTC treatment had a higher grass abundance (OTC treatment grass cover ≈24.0%; Control treatment grass cover ≈17.0%) and higher dry matter content (OTC treatment DM ≈1.70 t ha–1; Control treatment DM ≈1.50 t ha–1). The study suggests that climate warming triggers shifts in vegetation characteristics of high-altitude grasslands in the rugged mountainous terrain, but the magnitude of shift varies according to site characteristics. Under warming, the north-facing site could experience greater vegetation change, characterized by reduced species diversity, species richness, proportion of sedge, and crude protein content.
Rangeland vegetation in the Great Basin, United States, is frequently disturbed by natural- and human-caused wildfires that facilitate the establishment and dominance of introduced annual weeds such as cheatgrass (Bromus tectorum) and medusahead wildrye (Taeniatherum caput-medusae [L.] Nevski). Ecological resilience and resistance of native and seeded-non-native plant communities in this region, however, appear to follow topographic patterns associated with slope, aspect, and elevation. Currently, resistance and resilience concepts are being used to prioritize rangeland restoration efforts based on soil-climate classification. We hypothesized that probabilistic patterns of shorter-term weather effects on seedbed microclimate might also be correlated with these perceived spatial patterns of resistance and resilience over space. We used a 39-yr gridded weather dataset to estimate seedbed temperature and water potential at seeding depth as a function of slope and aspect using the Simultaneous Heat and Water (SHAW) model. Seedbed temperature and water potential were then used as input to hydrothermal germination response models to generate indices of seedbed favorability for initial germination and emergence and to estimate cumulative germination response as a function of topography and planting date for the very-fast-germinating cheatgrass, fast-germinating bottlebrush squirreltail (Elymus elymoides [Raf] Swezey), and slower-germinating Idaho fescue (Festuca idahoensis Elmer). Topographic mapping of seedbed favorability showed distinct seasonal patterns associated with both slope and aspect. Southern exposures are likely to facilitate both prewinter germination for early-fall-planted seeds and relatively more midwinter germination for seeds planted later in the fall, but these exposures are also less subject to midwinter frost effects. Northern exposures were likely to delay germination into later winter and early spring and thus avoid potential exposure to a higher probability of winter frost mortality. Microclimatic simulations of this type may provide new metrics for improving our understanding of the mechanistic causes of observed patterns of ecological resistance and resilience over space.
The potential drivers of grassland rent-in across the ecosystem types in Inner Mongolia are poorly understood. This study employed a methodology that integrates socioeconomic characteristics, ecological factors, and risk perception of herders into a framework to assess the influencing factors of the area of grassland rent-in by households. Also, we examine how the size of rented grassland influences herders' production and income characteristics and tested the relationship between households' herd structure and livestock production. Results show that the less area of grassland owned, the lower the household head's age was, and a decline in the time invested in other nongrazing activities leads to the rent-in of higher grassland area. Additionally, higher living expenses, loan income, and the frequency of snow disaster compel herders to rent-in more grassland areas. Compared with the “low-land-rent” households, the “high-land-rent” and “medium-land-rent” households had a lower stocking rate and higher total livestock income. A higher ratio of the different types of livestock in households' herds increases livestock production efficiency. This study highlights the need for policies that could help alleviate household living and production-related risks such as preventive and rapid snow disaster control and reduction of living expenses. Also, the provision of long-term loans free from the recurrent debt cycle and incentives to lessees for land improvement during the tenancy period are viable strategies needed to promote a well-functioning grassland rental market.
Restoring degraded plant communities is a global challenge and a major priority for land managers and conservationists. Degraded Wyoming big sagebrush communities (Artemisia tridentata ssp. wyomingensis [Beetle & A. Young] S.L. Welsh) have high sagebrush cover with a depleted perennial herbaceous understory. They are widespread in western North America and are a priority for restoration because they provide habitat for sagebrush-associated species and an important forage base for livestock production. Mechanically reducing sagebrush with mowing has been attempted to restore the understory in these communities but often fails because large native perennial bunchgrasses do not increase and exotic annual grasses proliferate. Seeding large native perennial bunchgrasses after mowing sagebrush may increase their density or cover and thereby limit exotic annual grasses. Native perennial bunchgrasses are slow growing; thus, long-term studies are needed to evaluate this treatment strategy. We evaluated mowing followed by drill-seeding large native perennial bunchgrasses in southeastern Oregon for 11 yr post treatment. Large bunchgrass cover and density were approximately 2 × greater with mowing followed by seeding compared with the untreated control. However, mowing, with and without seeding, increased exotic annual grasses and decreased biological soil crusts. Sagebrush cover was less in mowed treatments compared with the untreated control, but sagebrush cover increased over time. Mowing and seeding native bunchgrasses was less successful than desired, particularly since exotic annual grasses increased substantially. This treatment may be improved by reducing the disturbance associated with mowing and drill seeding, decreasing exotic annual grass competition, and increasing the establishment of native perennial bunchgrasses. The results of our study indicate that seeding native bunchgrasses into degraded Wyoming big sagebrush communities has potential as a restoration treatment but needs refinement to improve success.
Livestock distribution in extensive rangelands of North America can present management challenges to land managers. Understanding the role of topography on livestock distribution, within and across diverse rangeland ecosystems, could provide land managers valuable information for adaptive management of livestock to address both conservation and production goals from these ecosystems. Here, we examine the influence of topography on grazing distribution unevenness and intensity of use of beef cattle in seven rangeland ecosystems spanning arid, semiarid, and subtropical environments. We focused on grazing distribution during the late growing season (summer and autumn) periods when topographic variation in rangelands is more coupled to low and nonuniform availability of high-quality forage. Pasture size and water sources strongly influence grazing distribution across ecosystems. High unevenness of grazing occurred in pastures with extensive distances to water, low stock density, and more rugged topography. Conversely, more uniform grazing distribution occurred in smaller, well-watered pastures that support higher stock density (animals per unit area) and gentler terrain. Comparison of two topographic indices, topographic wetness index and topographic position class index, in terms of their ability to predict cattle grazing distribution, revealed that categorical topographic position classes were more effective. For most arid and semiarid rangelands, livestock grazing distributions showed affinities for lowlands and flat plains compared with open slopes and uplands. In contrast to drier rangelands, livestock grazing distributions exhibited preference for upland and sloped areas of subtropical pastures, as low-lying areas with water-inundation likely curtailed selection. Across these diverse rangeland ecosystems of North America, results provide benchmark information on livestock grazing distribution to formulate improvements in adaptive management and decision making and incorporate technological advancements in precision livestock management to integrate abiotic environmental information with spatial movements of livestock and temporal vegetation dynamics.
Watersheds are distinct hydrologic units that comprise a range of terrestrial upland and riparian complex ecological sites. Since the hydrologic function of the entirety of the watershed is linked, other ecological functions and processes are also likely linked. No single assessment tool is available to describe the ecological status of both terrestrial upland sites and riparian complexes in a single watershed. We investigated the relationship by integrating two assessment tools, Interpreting Indicators of Rangeland Health protocol (IIRH) and stream geomorphic surveys in prairie ecosystems. The qualitative values from the IIRH protocol were different among upland sites associated with 35 intermittent stream reaches in North Dakota in the United States. Riparian complex sites were separated using three metrics of stream stability: stream channel type, bank-height ratio, and Bank Erosion Hazard Index. Stream channel type had the strongest relationship with two attributes of rangeland health, Soil & Site Stability and Hydrologic Function, while bank-height ratio had the strongest relationship with the Biotic Integrity attribute. The influences of individual indicators were identified using a principal components analysis, which revealed unstable streams were typified by departures from the reference state in compaction, soil loss, bare ground, litter dynamics, infiltration, and invasive species. These findings suggest that changes in these IIRH indicators should be monitored and managed by land managers to ensure that riparian function and ecosystem services are not compromised. Future research must continue to investigate the link between upland and riparian functions within a watershed, with special emphasis on vegetation dynamics. In the meantime, integrating these two assessments can provide land managers with vital information about maintaining ecological function throughout the watershed.
Precipitation pulses and interpulse dry periods are major drivers of dryland ecosystem function globally, yet how the patterning and timing of precipitation inputs and dry periods influence seedling recruitment in these systems is poorly understood. We conducted two experiments to understand how limited and variable patterns of precipitation inputs may influence recruitment of bluebunch wheatgrass (Pseudoroegneria spicata [Pursh] A. Löve). In the first experiment, we evaluated how precipitation magnitude and dry-d interval during spring influenced recruitment. Ambient precipitation was excluded during spring, and we experimentally applied 5 levels of water (25, 35, 45, 55, and 65 mm) and 5-dry-d durations (1, 2, 4, 6, or 8 dry d between waterings) to plots sown with P. spicata. In the second experiment, we evaluated how the seasonal timing and duration of dry d influenced recruitment. All ambient precipitation was excluded through late winter and spring, and we experimentally applied three levels of dry-d duration (10, 20, and 30 d) four times during the growing season (February, March, April, and May) to plots sown with P. spicata. We observed strong, nonlinear interactive effects of precipitation amount and dry-d interval on recruitment where the midpoint dry-d treatment (4 d) interacted with low water availability to drive a major decline in recruitment. We also found strong evidence that recruitment was limited by dry periods occurring in late winter as opposed to dry periods occurring through spring, with recruitment decreasing over 40% during February dry periods compared with dry periods in March, April, or May. By understanding how precipitation pulses and interpulse dry periods interact to drive recruitment, we can refine efforts to develop weather-centric restoration frameworks, as well as hone ongoing efforts to identify plant materials and seed enhancement technologies that may buffer effects of variable precipitation on recruitment.
Ecologists have built numerous models to project how climate change will impact rangeland vegetation, but these projections of future changes are difficult to validate, making their utility for land management planning unclear. In the absence of direct validation, researchers can ask whether projections from different models are consistent. High consistency across models, especially those based on different assumptions, would increase confidence in using projections for planning. Here, we analyzed 19 models of climate change impacts on sagebrush (Artemisia tridentata Nutt.), cheatgrass (Bromus tectorum L.), pinyon-juniper (Pinus L. spp. and Juniperus L. spp.), and forage production on Bureau of Land Management (BLM) lands in the US Intermountain West. These models consistently projected the potential for pinyon-juniper declines and forage production increases. In contrast, models of cheatgrass mainly projected no climate change impacts, while sagebrush models projected no change in most areas and declines in southern extremes. In most instances, vegetation projections from high- and low-emission scenarios differed only slightly.
The projected vegetation impacts have important management implications for agencies such as the BLM. Pinyon-juniper declines would reduce the need to control pinyon-juniper encroachment, and increases in forage production could benefit livestock and wildlife populations in some regions. Sagebrush conservation and restoration projects may be challenged in areas projected to experience sagebrush declines. Similar projections from high- and low-emission scenario models may increase confidence to consider model projections in planning. However, projected vegetation impacts may also interact with increasing future wildfire risk in ways single-response models do not anticipate. In particular, forage production increases could increase management challenges related to fire.
Tall fescue (Schedonurus arundinaceus), an exotic invasive grass in North America, can associate with a fungal endophyte that causes livestock toxicity. Native prairies are frequently managed with interactive fire and grazing, yet little is known regarding tall fescue's endophytic and toxicological responses. From 2012 to 2014, we applied patch-burn grazing (PBG—burning a different third annually) or graze and burn (GAB—burning completely in 2012 but no fire in 2013 or 2014) treatments to tall fescue–invaded grasslands. Burning happened in March/April, and cattle grazing occurred during the growing season. Tall fescue tillers were analyzed for Epichloë endophyte presence and alkaloid concentrations (ergovaline, ergovalinine, N-acetylnorloline, N-formylloline, N-acetylloline). Cattle toxicosis was assessed via fecal ergovaline levels. With PBG, tiller defoliation was greater in burned patches versus unburned and was greater than any years in GAB. In GAB, tiller defoliation was no different the year of the burn than the years without fire. Cattle did not discriminate between endophyte-infected or endophyte-free tillers in either treatment. Endophyte infection levels were inversely related to years since fire (YSF), and various alkaloids displayed asynchronous responses to YSF. Cattle had no detectable fecal ergovaline when managed with patchy or complete pasture fires. Only two herds had detectable fecal ergovaline (> 100 ppb), which were in pastures managed without fire and only in 2013. Thus, patch burning tall fescue–invaded grasslands alters alkaloids and tiller defoliation with implications for cattle toxicosis. Future research should incorporate greater intra-annual resolution of plant phenology relative to focal grazing and alkaloid expression.
This paper calls attention to the factors that contribute to predicting behavioral intention to cultivate medicinal and aromatic plants (MAPs) in farmlands, as social-psychological and microeconomic features of the adopter and nonadopter farmers are compared. Against the previous studies that have established inductive-based hypotheses, this research, in turn, benefitted from a deductive-based approach (i.e., theory-driven) and recognized a knowledge gap of attitude-intention behavior and cost-benefit behavior in the case of the adoption of the cultivation of MAPs. Given the nature of the respective hypotheses, the study used a sample of 312 farmers, randomly clustered and selected from the rural areas of Sari and Maragheh Townships, Iran. The former is a leading site respecting the cultivation of MAPs (n1 = 89), and the latter is a less or underdeveloped region (n2 = 223). Respondents were asked to complete a self-implemented questionnaire, conceptually designed by the theory of planned behavior and rational choice theory and confirmed by Cronbach's alpha reliability method. Using the linear regression model, it was revealed that attitude, subjective norms, perceived behavioral control (PBC), and perceived costs are the drivers of intention. In contrast with the nonadopter farmers, adopter farmers have a more positive attitude (Hedges' g = 0.39), subjective norms (Hedges' g = 1.04), PBC (Hedges' g = 1.15), and intentions (Hedges' g = 0.93), as well as lower perceived costs (Hedges' g = 0.56). The study concluded that findings give insight to agricultural policymakers and extension agents in the field of promoting the cultivation of MAPs as a complement to conventional cropping patterns.
Maintaining healthy rangeland ecosystems requires adaptive co-management at the landscape scale. Because the majority of western rangelands are publicly owned, it is critical that federal land management agencies work together in generating and sharing information. Promotion and communication of rangeland management innovations among agencies is one means of sharing information. Two rangeland management innovations, the Weather-Centric Restoration Tool and Interpreting Indicators of Rangeland Health, were studied in order to better understand agency adoption decisions and barriers to diffusion of the innovations across agencies. Using a mixed qualitative methodology, we interviewed land managers across the floristic Great Basin and in southeastern Utah responsible for making or advising rangeland management decisions. Using thematic analysis of participant interviews and land managers' social networks in southeastern Utah, we were able to identify variables at the innovation, individual, organization, and external system levels that affect innovation adoption and diffusion across agencies. In line with previous research, desirable innovation traits were related to five constructs: complexity, relative advantage, compatibility, trialability, and observability. Interagency siloing was found to be the biggest factor affecting individual and organization-level adoption decisions. External sociopolitical factors were also found to create organization-level barriers including funding streams, legal considerations, and differing institutional cultures between agencies. While management innovations are hindered by these hurdles, innovations also serve as promoters of institutional change that reshape these constraints. However, overcoming barriers to innovation requires the presence of innovation champions who can influence both incremental bottom-up and top-down processes.
Throughout the Rolling Plains and Cross Timbers ecoregions of Texas, native grassland plant communities have been converted into low-diversity plant communities by long-term, intensive overgrazing by cattle and fire suppression. Much of the historical plant community has become dominated by annuals, Texas wintergrass (Nassella leucotricha), and honey mesquite (Prosopis glandulosa). This degradation has been so severe that many native bird species, including Northern bobwhite (Colinus virginianus), have experienced drastic population declines. We conducted a small-plot study to determine effective management actions for transforming mesquite savanna–Texas wintergrass communities to diverse native plant communities supportive of native wildlife species. We tested multiple management practices following mechanical mesquite brush removal, including seeding, timed treatments of herbicide, prescribed burns, and high-intensity, short-duration cattle grazing. Results indicated that plots receiving early spring treatments of herbicide followed by burning and grazing over 2 consecutive yr best reduced cool-season grasses and promoted overall restoration goals by increasing native warm-season grass and forb establishment.
Social networks of stakeholders, especially those of adaptive comanagement, entailing a variety of collaboration and trustful relationships, have widely drawn the attention of researchers studying natural resource management. The structural pattern of relations of a social network has significant implications for how actors manage complex environmental challenges. This study aimed to specify whether existing network structure (trust and collaboration ties) and the position of actors within the social network of Nariyan village stakeholders have led to unsuccessful rangeland comanagement. The social network of stakeholders in the study region included rangeland users and governmental and nongovernmental agencies. Social network analysis is a recent tool that was applied in this study to quantitatively specify the roots of unsuccessful comanagement in the Nariyan village located in the Taleghan region. It is shown that there is a rather low level of trust and collaboration between local stakeholders (rangeland users) and regional governmental and nongovernmental organizations. This is one of the main challenges impeding successful rangeland comanagement in this region. Furthermore, the article specifies the actors who may contribute to the effective comanagement in advantageous positions.
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