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Ecosystem services are benefits humans obtain as a result of ecosystem processes and conditions. In the western United States, public rangelands are managed for a spectrum of ecosystem services on behalf of multiple stakeholders. Decisions of ranchers who hold public land grazing allotments must balance operational needs for forage with societal expectations for other ecosystem services. To better understand their choices regarding ecosystem services, we interviewed ranchers to learn about the bases for their management decisions and identify services they believe rangelands provide. A total of 19 services were identified, many of which reflected ranchers’ recognition that they manage within the context of a broader social-ecological system (e.g., maintaining open space). We then conducted a mail survey of Bureau of Land Management grazing permittees in six states to understand the importance they personally place on different services, as well as the extent to which they manage with those services in mind. Fourteen of the 19 ecosystem services identified in interviews were reported by at least 50% of the survey sample (N = 435) as influencing their management decisions. Most respondents reported trying to manage deeded and leased land to the same standard. Aside from forage for livestock (ranked #1), ranchers were less likely to report managing for provisioning services than for cultural, supporting, and regulating services. Importance ratings for ecosystem services followed a similar pattern, although there were a few differences in rank order. Ranchers tended to report managing for more ecosystem services if they had larger operations, earned at least 50% of their income from ranching, spent more time out on the ranch, and relied on multiple sources for information about range management. Results indicate public land ranchers believe they are managing for multifunctionality, balancing their own operational needs with those of society.  相似文献   

3.
Most of the world's rangelands are subject to large spatial and temporal variation in forage quantity and quality, which can have severe consequences for the stability and profitability of livestock production. Adaptive foraging movements between functional seasonal resources can help to ameliorate the destabilizing effects on herbivore body stores of spatial and temporal variability of forage quantity and quality. Functional dry-season habitats (key resources) provide sufficient nutrients and energy to minimize reliance on body stores and are critical for maintaining population stability by buffering the effects of drought. Functional wet-season habitats dominated by short, nutritious grasses facilitate optimal intake of nutrients and energy for lactating females, for optimal calf growth rates and for building body stores. Adaptive foraging responses to high-quality focal patches induced by rainfall and disturbance further facilitate intake of nutrients and energy. In addition, focused grazing impact in high-quality patches helps to prevent grassland maturing and losing quality. In this regard, the design of many rotational grazing systems is conceptually flawed because of their inflexible movement of livestock that does not allow adaptation to spatial and temporal variability in forage quantity and quality or sufficient duration of stay in paddocks for livestock to benefit from self facilitation of grazing. Similarly the fixed intraseasonal resting periods of most rotational grazing systems might not coincide with the key pulses of nitrogen mineralization and rainfall in the growing season, which can reduce their efficiency in providing a functional recovery period for grazed grasses. This might explain why complex rotational grazing systems on average have not out-performed continuous grazing systems. It follows, therefore, that ranchers need to adopt flexible grazing management practices that allow adaptation to spatial and temporal variability in forage quantity and quality, allow facilitation of grazing (season-long grazing), and allow more effective recovery periods (season-long resting).  相似文献   

4.
In Great Plains rangelands, drought is a recurring disturbance. Ranchers in this region expect to encounter drought but may not be adequately prepared for it. Efforts to encourage drought preparedness would benefit from a better understanding of the conditions under which managers make decisions to minimize the impacts of drought. We tested the direct and moderating roles of the drought hazard and the social-ecological context on drought impacts and response. This study was conducted with ranchers in western and central South Dakota and Nebraska following the drought that began in 2012. We surveyed ranchers regarding the effects of the drought and their responses and used multimodel analysis to explore the relationships among measures of drought preparedness, drought response, and drought impacts. Drought severity was the primary predictor of all impacts, but specific types of impacts were varied depending on the operation’s enterprise mix, resources, and management. The socioecological characteristics of the ranch system predicted drought response actions taken, by either providing the necessary resources and capacity to take action or creating sensitivity in the system that required action to be taken. We conclude with recommendations for learning from current drought experiences in order to better adapt to future drought events.  相似文献   

5.
Experiments investigating grazing systems have often excluded ranch-scale decision making, which has limited our understanding of the processes and consequences of adaptive management. We conducted interviews and vegetation monitoring on 17 ranches in eastern Colorado and eastern Wyoming to investigate rancher decision-making processes and the associated ecological consequences. Management variables investigated were grazing strategy, grazing intensity, planning style, and operation type. Ecological attributes included the relative abundance of plant functional groups and categories of ground cover. We examined the environmental and management correlates of plant species and functional group composition using nonmetric multidimensional scaling and linear mixed models. After accounting for environmental variation across the study region, species composition did not differ between grazing management strategy and planning style. Operation type was significantly correlated with plant community composition. Integrated cow-calf plus yearling operations had greater annual and less key perennial cool-season grass species cover relative to cow-calf  only operations. Integrated cow-calf plus yearling ranches were able to more rapidly restock following drought compared with cow-calf operations. Differences in types of livestock operations contributed to variability in plant species composition across the landscape that may support diverse native faunal species in these rangeland ecosystems. Three broad themes emerged from the interviews: 1) long-term goals, 2) flexibility, and 3) adaptive learning. Stocking-rate decisions appear to be slow, path-dependent choices that are shaped by broader social, economic, and political dynamics. Ranchers described having greater flexibility in altering grazing strategies than ranch-level, long-term, annual stocking rates. These results reflect the complexity of the social-ecological systems ranchers navigate in their adaptive decision-making processes. Ranch decision-making process diversity within these environments precludes development of a single “best” strategy to manage livestock grazing.  相似文献   

6.
Summer droughts in North America's northern Great Plains are expected to increase in frequency and duration as precipitation shifts toward spring and fall. Two rangeland experimental stations in North Dakota experienced drought in 2017 relative to 25-year averages. The southwest location had a 170-mm deficit from the 360-mm normal rainfall and was grazed by cattle (Bos taurus L.) and sheep (Ovis aries L.); the south-central location had 109 mm below the 403-mm normal rainfall and was grazed by cattle. We evaluated patch-burn grazing as a drought resilient land management strategy in the northern Great Plains by comparing average daily gains, fecal density, available forage biomass, and forage crude protein content. At the southwest location, livestock performed better during the drought season compared with animals on the same pastures in the previous year, which had near-normal rainfall but no fire. At the central location, cows on patch-burned pastures performed better than cows on continuously-grazed, unburned pastures in the same year under drought conditions; all cows were nursing calves and calf gains did not vary between treatments. In both locations, the burned patches had higher fecal density and lower available forage biomass than patches not yet burned throughout the grazing season, indicating grazer attraction to burned areas. Despite drought, burned patches maintained grazer attraction and animal performance was maintained or even improved, which contrasts with the expected relationship between animal performance and precipitation. This study indicated that prescribed patch-burning might mitigate drought by buffering forage resources (crude protein content and availability) and maintaining animal performance (average daily gains).  相似文献   

7.
Individual forage species were appraised in varying distances along transects radiating from the water points of the ranch and traditional cattle post management systems. Measurements of plant height were used to assess the degree of forage species utilisation by livestock around water points. Livestock use forage plants more heavily near water points and the degree of use is more pronounced in the traditional cattle post areas, compared to ranch grazing. Utilisation of annual plants occurring at the 0m zone from water was greater than that of the same plant species growing at further distances. Periodic closure of water points aimed at reducing grazing pressure has been indicated as a method to promote production of forage around water points. With the exception of Panicum maximum, the abundance of which was low or non-existent in both management systems, Digitaria eriantha was the most utilised grass by livestock, followed by Schmidtia pappophoroides and Eragrostis lehmanniana. Stipagrostis uniplumis, one of the dominant grasses in the Kalahari Sandveld, exhibited a weak tendency to decline as distance from water increased. It was observed that high forage utilisation rates coincide with drought periods, implying that correct stocking rate adjustments should always match the available forage. Forage utilisation from water points in the traditional cattle post areas extended beyond 4 000m, especially during the dry periods.  相似文献   

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影响牧草再生性的因素分析   总被引:3,自引:3,他引:3  
对影响牧草再生性的诸因素进行了分析,阐明了牧草再生性对刈割和放牧利用方式的响应,以及刈割和放牧后牧草体内贮藏的碳水化合物和氮素在再生中的变化规律及作用,为草地的放牧利用和刈割提供了理论和技术依据。  相似文献   

10.
Exposure of livestock grazing to forage productivity variation and to market fluctuations affects the risk of investment and returns from cow-calf operations, but little work has been done to empirically compare these returns to the returns that would be demanded by financial markets from assets with similar risk and return characteristics. This study uses historical forage production data from three rangeland locations in California, and cattle and hay prices, to simulate financial statements for three hypothetical cow-calf producers in the period 1988–2007. Return on investment from year to year incorporates the variability and risk associated with dependence on natural forage production. Performance is then compared to the actual performance of a diversified portfolio of assets using the Capital Asset Pricing Model, from which the theoretical cost of capital for these hypothetical grazing enterprises is derived. Much like other agricultural enterprises, cow-calf production in California has low market risk and a low theoretical cost of capital. This theoretical cost of capital is still greater than the historical return from livestock production (excluding land appreciation) in the western United States, adding further backing to the point often made in the literature that ranchers who engage in cow-calf production are receiving benefits beyond the commercial returns from livestock production alone.  相似文献   

11.
The goal of our study was to document traditional steppe herders' perception and management of spatial and temporal heterogeneity of forage availability of their seminatural pastures. Ninety-two herders living in the Hortobágy saline steppe, Hungary, Central Europe were interviewed, and participatory observation was used to understand herding and habitat improvement techniques. The herders recognized 47–66 habitat types (mostly grassland types), and listed at least 90 plant species important for grazing. They have a nuanced knowledge of the intra- and interannual variations of forage quality and quantity. They perform very strong and well-planned herding practices. Daily spatial pattern of grazing is, however, often opportunistic and flexible, but has a more-or-less regular year-round cycle, in which marshes and stubbles provide forage in drought periods. Reciprocal learning and continuous communication between the herder and his driving dogs and livestock strongly influence grazing pattern. Herders manage and improve different habitats of their pastures differently by traditional and, less frequently, modern methods. The main method is grazing supplemented by manuring, burning, and removal of spiny weeds. Traditional knowledge of herders could be effectively used in evidence-based conservation and pasture management of European saline steppes; e.g., the reintroduction of some old herding techniques (opportunistic pasture use, grazing of marshes, and burning). Herders' knowledge could also help the fine-tuning and local adaptation of European agri-environmental regulations (e.g., how to balance subsidies for hay-making and grazing in saline steppes). More research is needed, however, on the ecological effects of different traditional grazing techniques, e.g., rotation, manuring, and burning. In general a more complex socio-ecological understanding of the internal and external factors affecting adaptation of the Hortobágy herders to changing environment, society, and European Union policies is needed.  相似文献   

12.
Rotational grazing systems (RGS) are often implemented to alleviate undesirable selective grazing by livestock. At both fine and coarse scales, livestock selectively graze individual plants, patches, communities, and landscapes. Smaller pastures, increased stocking density, and rotation allow managers to constrain livestock movement and determine season and frequency of grazing, potentially limiting selectivity and preventing repeated grazing of preferred plants. However, in arid and semi-arid rangelands, forage growth is limited primarily by precipitation rather than defoliation frequency. When soil moisture is adequate, forage is abundant and defoliation levels are typically low, and repeated, intensive defoliation of preferred plants is less likely than in more mesic areas where more consistent precipitation and soil moisture storage allows animals to establish and maintain spatial hierarchies of grazing patterns. Many southwestern rangelands contain diverse vegetation, which provides quality forage during different times of the year. These spatial and temporal patterns of forage distribution may not be amenable to manipulation with RGS. Tracking data show that livestock often alternate among locations within pasture boundaries and can opportunistically exploit areas with higher quality forage when they are available. Higher stock densities combined with higher stocking rates can increase livestock use of less preferred areas, but overall distribution patterns of intensive-rotational and extensive grazing systems are often comparable at similar stocking rates and distances from water. Management that ensures that grazing of riparian areas does not occur during the critical late summer period may be more beneficial than RGS that periodically defers livestock use throughout the grazing season. In arid and semi-arid shrublands, timely adjustments to animal numbers and practices that improve grazing distribution at regional and landscape scales are more likely to be effective in maintaining or improving rangeland health than fencing and RGS.  相似文献   

13.
Research on the impacts of wildfire and invasive plants in rangelands has focused on biophysical rather than human dimensions of these environmental processes. We offer a synthetic perspective on economic and social aspects of wildfire and invasive plants in American deserts, focusing on the Great Basin because greater research attention has been given to the effects of cheatgrass expansion than to other desert wildfire/invasion cycles. We focus first on impacts at the level of the individual decision-maker, then on impacts experienced at the human community or larger socio-political scales. Economic impacts of wildfire differ from those of invasive grasses because although fire typically reduces forage availability and thus ranch profit opportunities, invasive grasses can also be used as a forage source and ranchers have adapted their grazing systems to take advantage of that circumstance. To reduce the threat of increased ranch bankruptcies, strategies are needed that can increase access to alternative early-season forage sources and/or promote diversification of ranch income streams by capturing value from ranch ecosystem services other than forage. The growth of low-density, exurban subdivisions in Western deserts influences not only the pattern and frequency of wildfire and plant invasions but also affects prevailing public opinion toward potential management options, and thereby the capacity of land management agencies to use those options. Outreach efforts can influence public opinion, but must be rooted in new knowledge about multiple impacts of invasion and increased wildfire in American deserts.  相似文献   

14.
It is hypothesized that Utah beef producers in certain locations could intensify private land use via improved forages and irrigation. Although intensification could increase ranch productivity and help compensate for any future restrictions in public grazing, is the approach profitable and sustainable in a dynamic environment? We investigated the efficacy of intensification using linear programming for three size-classes of model ranches. Model solutions maximize returns net of forage costs; outputs include brood-herd dynamics, optimal forage mixes, and net returns. The model is driven by 11-year risk scenarios combining high or low precipitation with high or low beef prices. We then consider current or no access to public grazing—a policy uncertainty. In general, results support the idea that intensification could be profitable, sustainable, and strategically useful under several sets of conditions. Modeled brood-herds expand and contract in response to precipitation. Optimal forage use is dominated by reliance on treated, improved, and irrigated forages. Critical irrigated forages include alfalfa hay and improved pasture. Profitability generally increases with operation size, but when public grazing is eliminated, herd sizes and profitability drop. Small and medium-sized operations respond to loss of public grazing by using more irrigated pasture and alfalfa hay, while larger operations use a wider variety of irrigated and nonirrigated forages. Sensitivity analysis indicates that optimal forage mixes for all operations remain stable even when input costs for fossil fuels double. Further increases in fuel costs, however, begin to reduce the contributions from irrigated pasture and alfalfa hay. Low precipitation (drought) has very large and negative effects on profitability in general. When drought combines with restricted access to public grazing, profitability of small and medium-sized operations drops further while profitability of large operations increases. Empirical research is needed to test model results and examine what the limiting assumptions reveal about real-world production constraints.  相似文献   

15.
The potential of invasive plants to alter fuel properties over time has implications for the ranchers of semiarid rangelands throughout the world. A prime example of this phenomenon is the cheatgrass (Bromus tectorum L.) invasion of the native shrub-steppe lands in Great Basin of the western United States. The purpose of this study is to develop a bioeconomic model that optimizes simulated ranch behavior given the beginning stages of cheatgrass invasion on a public forage allotment. The bioeconomic model is applied to a typical eastern Oregon 300 cow-calf ranch. Livestock production decisions are simulated over a 40-yr planning horizon using a multiperiod linear programming model. Results showed changes in profit-maximizing ranch management strategies in the form of decreased optimal stocking rates and forage substitution. The net present value of the simulated ranch’s income stream declined, and the probability that the ranch cannot meet its full costs of livestock production and would exit the industry increased as a result. These economic impacts were more pronounced with decreased sale price. Sensitivity analysis showed that overall results in terms of ranch behavior were specific neither to the assumed discount rate nor to the assumed percentage of cheatgrass cover (as long as this percentage is within the reference state) on the public grazing allotment. This study introduces a method for managers to quantify impacts on ranches from fuel-altering invasive plants on public lands, emphasizing the importance of including information about native and invasive forage production characteristics and wildfire frequency as a function of the state of invasion.  相似文献   

16.
Due to their complex structure and traditional low-intensity management, Portuguese oak woodland rangelands known as montados are often considered high nature value (HNV) farming systems, and as such, they may be deemed eligible for subsidies and incentives by governmental and nongovernmental agencies. Too little is known about how the HNV concept might be applied to conserve complex silvopastoral systems. These systems, due to their structural and functional complexity at multiple scales, tend to support high levels of biodiversity. Montados are in sharp decline as a result of the rapid specialization of land management that, through simplification, undermines multifunctionality. Understanding how changes in management influence these systems and their biodiversity is needed for prioritizing conservation efforts and for ensuring they remain HNV systems. On the basis of a field survey in 58 plots distributed among 29 paddocks on 17 farms, we conducted an integrated analysis of the relationship between grazing intensity and biodiversity in montados of similar biophysical and structural characteristics. Data on management were obtained through interviews, and biodiversity data (vegetation, macrofungi, birds, herpetofauna) were obtained through specific field protocols. Additional spatial data, such as soil characteristics, slope, land cover, and linear landscape elements, were also analyzed. The results show no overall biodiversity variation as a result of different management practices. However, different groups of species react differently to specific management practices, and within a pasture, grazing impacts are heterogenous. In low grazing intensity plots, macrofungi species richness was found to be higher, while bird species richness was lower. Using tree regeneration as proxy for montado sustainability, results show less tree regeneration in areas with higher forage quality and more intense grazing. Pathways for future progress are proposed, including creating areas within a paddock that attract grazing away from where regeneration is desired.  相似文献   

17.
Supplementation of grazing cattle is a routine management practice that serves several purposes. It can be used to fill the gaps created by seasonal deficiencies in forage growth and quality. Supplementation can also extend pasture availability during drought, increase the carrying capacity of the pasture, and provide nutrients that are inadequate or missing in the forage. Supplementation can also be used effectively to dilute anti-quality factors present in certain forages. Locally available by-products of the grain and food-processing industries can provide a cost-effective source of nutrients to balance the nutritional needs of grazing cattle. It is expected that the availability and cost effectiveness of these feeds will only grow as cattle compete with the biofuels industry for grain in the future.  相似文献   

18.
岑慧连  唐祈林 《草业科学》2016,33(3):535-539
为了解我国西南地区种养殖业与饲用作物种植的发展情况,本研究基于《中国农业年鉴数据库》,查阅了1981-2012年近30年的资料,结合资料和西南地区的实情,对西南四省农区近30年来种植业、农牧比例以及养殖业变化情况进行了分析,旨在为该区发展饲用作物、调整种植业结构提供科学依据。西南地区种植业仍是以粮食为主导,经济作物其次,饲用作物种植偏低,畜牧业仍是养猪为主,草食牲畜在稳步增长。  相似文献   

19.
Recommended strategies for dealing with drought include maintaining a conservative stocking rate, maintaining grazing flexibility by having yearlings as one of multiple enterprises on the ranch, and leaving a significant amount of herbaceous production at the end of the grazing season. We perform an economic analysis of these grazing strategies using a bio-economic multiperiod linear programming model with variable annual forage production and beef prices. We evaluate the economics of conservative versus flexible grazing where stock numbers are adjusted to match forage conditions. The deterministic model estimates that a flexible grazing strategy could nearly double net returns relative to a conservative strategy, but realizing this substantial economic potential means higher production costs, and it depends on a quality climate forecast that is not currently available. Maintaining grazing flexibility was determined to be very important for managing variable forage conditions, and its importance increased with the level of variability. Without annual variation in forage production, over 80% of available forage would optimally be allocated to cow–calf production. As forage variability increased to levels observed on the arid rangelands of the western United States, a 50:50 forage allocation between cow–calf and yearling enterprises was found to be optimal, but optimal cow numbers decreased over time as dry conditions force herd reductions. As compared to a cow–calf ranch only, adding flexible yearling enterprises increased average annual net ranch returns by 14% with conservative stocking and by up to 66% with flexible grazing. Herd expansion beyond a conservative level should occur with yearlings because adjusting cow numbers is too expensive relative to the potential short-term gain, even if forage conditions are known with certainty.  相似文献   

20.
The ecological impacts of rangeland invasive plants have been widely documented, but the social aspects of how managers perceive their impacts and options for control have been relatively understudied, and successful, long-term invasive plant management programs are limited. In particular, though a growing body of research has identified livestock grazing as the most practical and economical tool for controlling invasive rangeland plants, to date there has not been a systematic assessment of the challenges and opportunities producers and other land managers see as most important when considering using livestock to manage invasive plants. In-depth, semistructured interviews with California annual grass and hardwood rangeland ranchers, public agency personnel, and nongovernmental organization land managers were used to address this need. Although interviewees broadly agreed that grazing could be an effective management tool, differences emerged among the three groups in how they prioritized invasive plant control, the amount of resources devoted to control, and the grazing strategies employed. Interviewees identified key challenges that hinder broad-scale adoption of control efforts, including the potential incompatibility of invasive plant management and livestock production; a lack of secure, long-term access to land for many ranchers; incomplete or insufficient information, such as the location or extent of infestations or the economic impacts to operations of invasive plants; and the temporal and spatial variability of the ecosystem. By identifying key socioecological drivers that influence the degree to which livestock are used to manage invasive plants, this study was able to identify potential pathways to move our growing understanding of the science of targeted grazing into practice. Research, extension, and grazing programs that address these barriers should help increase the extent to which we can effectively use livestock to slow and perhaps reverse the spread of some of our most serious rangeland weeds.  相似文献   

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