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1.
Developing countries must consider the influence of anthropogenic dynamics on changes in rangeland habitats. This study explores happened degradation in 178 rangeland management plans for Northeast Iran in three main steps: (1) conducting a trend analysis of rangeland degradation and anthropogenic dynamics in 1986-2000 and 2000-2015, (2) visualizing the effects of anthropogenic drivers on rangeland degradation using bivariate local spatial autocorrelation (BiLISA), and (3) quantifying spatial dependence between anthropogenic driving forces and rangeland degradation using spatial regression approaches. The results show that 0.77% and 0.56% of rangelands are degraded annually during the first and second periods. The BiLISA results indicate that dry-farming, irrigated farming and construction areas were significant drivers in both periods and grazing intensity was a significant driver in the second period. The spatial lag (SL) model (wi=0.3943, Ei=1.4139) with two drivers of dry-farming and irrigated farming in the first period and the spatial error (SE) model (wi=0.4853, Ei=1.515) with livestock density, dry-farming and irrigated farming in the second period showed robust performance in quantifying the driving forces of rangeland degradation. To conclude, the BiLISA maps and spatial models indicate a serious intensification of the anthropogenic impacts of ongoing conditions on the rangelands of northeast Iran in the future.  相似文献   

2.
Aborigines, because of their population numbers and increasing control over land and resources, are crucial to the sustainable development of rural Australia. However, appropriate Aboriginal development requires the replacement of the ‘top‐down’ approaches generally adopted by government agencies by ‘bottom‐up’ approaches reflecting the needs and aspirations of rural Aboriginal people. Past experience demonstrates that Aborigines have faced many frustrations in reconciling these concepts. But some approaches now being adopted in the use and management of Australia's rangelands provide interesting alternatives which may be more generally applicable in enhancing rangeland sustainability. Examples include land‐use practices conducted by Aborigines living in remote homeland centres on their own freehold land, and the diversity of land uses introduced on pastoral stations now under Aboriginal ownership. Broader recognition of the value of these approaches will depend on widespread acknowledgment of the overall worth of Aboriginal land management knowledge in rural restructuring  相似文献   

3.
Maintaining the health and productivity of rangelands by controlling the livestock stocking rate to remain within carrying capacity is of significance to ensure sustainable management of rangeland ecosystems. But we know little about the safe carrying capacity in particular rangeland landscapes. This has hampered efforts to use rangelands in a risk-averse manner in fluctuating rainfall environments, and especially in arid and semiarid areas. To address this lack of information, we took Kailash Sacred Landscape in China (KSL-China) as our study site and used remote sensing data, meteorological data and statistical data from 2000 to 2015 to analyze rangeland carrying capacity, stocking rate, and major influencing factors. Rangeland carrying capacity presented an increasing trend, while stocking rate was gradually decreasing, resulting in an increase of carrying rate in the study area. The increased carrying capacity was closely related to increased rainfall. Stocking rate declined owing to government regulations, particularly implementation in 2004 of the national policy of Returning Grazing Land to Grassland. There was a sharp reduction of livestock number below 200 000 standard sheep units (SU) after 2005. The decrease of stocking rate had a stronger effect on rangeland carrying rate than did the increase of carrying capacity. Ecosystem restoration programs have provided subsidies to pastoralists to encourage them to reduce livestock numbers. Our findings suggest that a safe rangeland carrying capacity is ca. 170 000 SU in KSL-China. There is a carrying capacity surplus of ca. 50 000 SU for safe animal husbandry development in the study area. More importantly, future climate warming and increases in grazing may jointly play a key role in affecting rangeland carrying capacity.  相似文献   

4.
Animal husbandry and crop farming are specialized for development in separate areas on the Tibetan Plateau. Such a pattern of isolation has led to current concerns of rangeland and farming system degradation due to intensive land use. The crop-livestock integration, however, has been proven to increase food and feed productivity thorough niche complementarity, and is thereby especially effective for promoting ecosystem resilience. Regional synergy has emerged as an integrated approach to reconcile rangeland livestock with forage crop production. It moves beyond the specialized sectors of animal husbandry and intensive agriculture to coordinate them through regional coupling. Therefore, crop-livestock integration (CLI) has been suggested as one of the effective solutions to forage deficit and livestock production in grazing systems. But it is imperative that CLI moves forward from the farm level to the regional scale, in order to secure regional synergism during agro-pastoral development. The national key R & D program, Technology and Demonstration of Recovery and Restoration of Degraded Alpine Ecosystems on the Tibetan Plateau, aims to solve the problems of alpine grassland degradation by building up a grass-based animal husbandry technology system that includes synergizing forage production and ecological functioning, reconciling the relationship between ecology, forage production and animal husbandry, and achieving the win-win goals of curbing grassland degradation and changing the development mode of animal husbandry. It is imperative to call for regional synergy through integrating ecological functioning with ecosystem services, given the alarming threat of rangeland degradation on the Tibetan Plateau. The series of papers in this issue, together with those published previously, provide a collection of rangeland ecology and management studies in an effort to ensure the sustainable use and management of the alpine ecosystems.  相似文献   

5.
赵雪 《中国沙漠》2000,20(Z2):167-170
豫北平原的沙质草地分布于黄河多次泛滥改道冲积形成的沙丘、沙地。其主要类型有:①以白茅、达乌里胡枝子为主的草从草地;②刺槐、杨树等林地下层以藜、白茅、茜草等为主的林下草地;③以碱茅、狗牙根等为主的低湿草地。沙质草地的主要特征为种类组成简单,牧草产量低(<2 000 kg·hm-2)且利用过度。但多种优良栽培牧草在沙地生长良好,可获较高产量。在沙地开发中,应针对各草地类型采取相应措施改造为人工、半人工草地。同时应结合沙地多种林木、果树和经济作物种植,建设农牧林复合经营的系统。畜牧业开发应以产业化为主导,发展适应市场需求的优良畜种,实行适度规模经营。  相似文献   

6.
Rangeland systems play an important role in ecological stabilization and the terrestrial carbon cycle in arid and semiarid regions. However, little is known about the vegetative carbon dynamics and climatic and topographical factors that affect vegetative carbon stock in these rangelands. Our goal was to assess vegetative carbon stock by examining meteorological data in conjunction with NDVI (normalized difference vegetation index) time series datasets from 2001-2012. An improved CASA (Carnegie Ames Stanford Approach) model was then applied to simulate the spatiotemporal dynamic variation of vegetative carbon stock, and analyze its response to climatic and topographical factors. We estimated the vegetative carbon stock of rangeland in Gansu province, China to be 4.4× 1014 gC, increasing linearly at an annual rate of 9.8×1011 gC. The mean vegetative carbon density of the whole rangeland was 136.5 gC m-2. Vegetative carbon density and total carbon varied temporally and spatially and were highly associated with temperature, precipitation and solar radiation. Vegetative carbon density reached the maximal value on elevation at 2500-3500 m, a slope of >30°and easterly aspect. The effect of precipitation, temperature and solar radiation on the vegetative carbon density of five rangeland types (desert and salinized meadow, steppe, alpine meadow, shrub and tussock, and marginal grassland in the forest) depends on the acquired quantity of water and heat for rangeland plants at all spatial scales. The results of this study provide new evidence for explaining spatiotemporal heterogeneity in vegetative carbon dynamics and responses to global change for rangeland vegetative carbon stock, and offer a theoretical and practical basis for grassland agriculture management in arid and semiarid regions.  相似文献   

7.
This article explores the potential impact of training and employment with wildfire management agencies on the retention of Indigenous fire knowledge. It focuses on the comparative knowledge and experiences of Indigenous Elders, cultural practitioners, and land stewards in connection with “modern” political constructs of fire in New South Wales and Queensland, Australia, and California in the United States of America. This article emphasises the close link between cross-cultural acceptance, integration of Indigenous and agency fire cultures, and the ways in which knowledge types are shared or withheld. While agency fire fighting provides an opportunity for Indigenous people to connect and care for country, it simultaneously allows for the breaking of traditional rules surrounding what knowledge is shared with whom in the context of Indigenous cultural burning. By highlighting how privilege intersects with ethnicity, class, gender and age, this article demonstrates how greater cross-cultural acceptance could aid ongoing debates on how to coexist with wildfire today.  相似文献   

8.
Wildfire is one of several potential disturbances that could have extraordinary impacts on individuals and communities in fire-prone areas. In this article we describe disturbance risk perceptions from interviews with residents in three Florida communities that face significant wildfire and hurricane risk. Although they live in areas characterized by emergency managers as having high wildfire risk and many participants have direct experience with wildfire, residents tended to share high hurricane and low wildfire risk perceptions. The different perceptions of risk seem linked to several factors: direct hurricane experience, different scales of impact, the local “hurricane culture,” effectiveness of local ordinances and development patterns, perceived predictability of the event, and perceived ability to control the event. This study shows that residents may perceive and act to reduce risk for one disturbance in relation to their perceptions, concern, and actions for another.  相似文献   

9.
The Jornada Experimental Range and the New Mexico State University Chihuahuan Desert Rangeland Research Center are fruitful areas to study the long-term effects of rangeland remediation treatments which started in the 1930s. A number of diverse manipulations were completed under the direction of federal agency and university scientists, and abundant remote sensing imagery is available to assist in relocating the treatments and evaluating their success. This is particularly important because few of the treatments were maintained following the loss of scientific personnel coinciding with the start of World War II, and most records of Civilian Conservation Corps scientific work were lost with the disbanding of the agency in 1942. Aerial photography, which was systematically used to image the United States beginning in the 1930s, can be used to identify types of treatments, measure areal coverage, estimate longevity, and help plan locations for new experiments. No long-lasting vegetation response could be determined for contour terraces, brush water spreaders, strips grubbed free of shrubs (despite the fact that these strips have remained visible for 65 years), and mechanical rootplowing and seeding. Distinct positive, long-term vegetation responses could be seen in aerial photos for water retention dikes, certain fenced exclosures, and some boundaries where different land management practices meet. It appears from both aerial photos and existing conventional records that experimental manipulation of rangelands has often been ineffective on the landscape scale because treatments are not performed over large enough contiguous areas and hydrological and ecological processes overwhelm the treatments. In addition, treatments are not maintained over time, treatment evaluation periods are sometimes too short, multi-purpose treatments are not used to maximize effects, and treatments are often not located in appropriate sites.  相似文献   

10.
Effective wildfire management is an essential part of forest firefighting strategies to minimize damage to land resources and loss of human lives. Wildfire management tools often require a large number of computing resources at a specific time. Such computing resources are not affordable to local fire agencies because of the extreme upfront costs on hardware and software. The emerging cloud computing technology can be a cost- and result-effective alternative. The purpose of this paper is to present the development and the implementation of a state-of-the-art application running in cloud computing, composed of a wildfire risk and a wildfire spread simulation service. The two above applications are delivered within a web-based interactive platform to the fire management agencies as Software as a Service (SaaS). The wildfire risk service calculates and provides daily to the end-user maps of the hourly forecasted fire risk for the next 112 hours in high spatiotemporal resolution, based on forecasted meteorological data. In addition, actual fire risk is calculated hourly, based on meteorological conditions provided by remote automatic weather stations. Regarding the wildfire behavior simulation service, end users can simulate the fire spread by simply providing the ignition point and the projected duration of the fire, based on the HFire algorithm. The efficiency of the proposed solution is based on the flexibility to scale up or down the number of computing nodes needed for the requested processing. In this context, end users will be charged only for their consumed processing time and only during the actual wildfire confrontation period. The system utilizes both commercial and open source cloud resources. The current prototype is applied in the study area of Lesvos Island, Greece, but its flexibility enables expansion in different geographical areas.  相似文献   

11.
Monitoring cattle inflows and outflows over time is a good indicator of herd productivity. In this study, ninety households were monitored for a year to determine the effect of season, rangeland type and herd size on births, purchases, sales, deaths, off-take, cattle production potential (CPP) and cattle production efficiency (CPE) in the sweet and sour rangelands of South Africa. Most births were recorded in large herds in the sour rangelands during the hot-wet season (P < 0.05). Farmers with large herd sizes purchased significantly more cattle compared to those with small herd sizes. Cattle sales were significantly high in the large herds in the cool-dry season. Mortality was significantly high in the hot-wet season in the sour rangeland and was mainly caused by gall-sickness (24%) and redwater (20%). The highest mortalities were observed in cows (45%). Households owning small herds in the sweet rangeland had the lowest CPP in the cool-dry season (P < 0.05). The CPE was significantly high in the households owning large herds in the sweet rangeland. It was concluded that, although the CPP was low in the sweet rangeland, households in these areas had higher CPE compared to those in the sour rangelands.  相似文献   

12.
To develop indicator–based management tools that can facilitate sustainable natural resource management by non–specialists, meaningful participation of stakeholders is essential. A participatory framework is proposed for the identification, evaluation and selection of rangeland condition indicators. This framework is applied to the assessment of rangeland degradation processes and sustainable natural resource management with pastoralists in the southern Kalahari, Botswana. Farmer knowledge focused on vegetation and livestock, with soil, wild animal and socio–economic indicators playing a lesser role. Most were indicators of current rangeland condition; however 'early warning' indicators were also identified by some key informants. This demonstrates that some local knowledge is process–based. Such knowledge could be used to improve indicator–based management tools and extension advice on the livelihood adaptations necessary to prevent or reduce ecological change, capable of threatening livelihood sustainability. There is evidence that social background influences indicator use. Communal farmers rely most heavily on vegetation and livestock indicators, whilst syndicate and land–owning pastoralists cite wild animal and soil–based indicators most frequently. These factors must be considered if indicator–based management tools are to meet the requirements of a diverse community.  相似文献   

13.
In South Africa, interventions in communal rangelands proposed by most agriculture-sector institutions are still dominated by the belief that communal herders have little technical skills and by the tenets of “the tragedy of the Commons”, assuming that individual livestock keepers are selfish, norm free, and aiming at maximising short-term offtake and that there is no consistent management of the commons. In this study we show that practices of a diversity of livestock keepers on the Leliefontein Commons of Namaqualand are at odds with this viewpoint: access to rangeland and its use are structured by collective norms and concerns regarding both the sharing of resources and their long-term sustainability. We also show that part of the management of the commons relies on grazing practices which involve tacit and formalised technical knowledge that can be described and modelled. Livestock keepers assess the heterogeneity of the grazing quality of the commons. They are aware of the toxicity and unpalatability of some plants, of the way this differs according to the amount ingested and the availability of other forage, and of the variations of these two factors over seasons of grazing. They classify grazing areas and decide on daily grazing routes according to a complex set of criteria. Carrying capacity of each area is not considered as a fixed parameter but rather as a variable dependant on rainfall. Seasonal movements between areas are designed accordingly. These findings offer a new perspective for research agendas on technical models and extension measures for communal rangeland management particularly in arid and semi-arid areas.  相似文献   

14.
Under the integrated influences of global climate changes and overgrazing, China rangeland has degraded over recent years. Maduo County locates in the Source Region of Yellow River and its rangeland has experienced expansive degradation. The government of Qinghai Province launched an eco- immigration policy in 2004. In order to analyze the responses of herd families to the eco- immigration and the reasons for these responses, the authors used three periods MSS and TM images for recent 25 years and interview survey data of 144 herd families in recent two years, getting the following results: (1) the rangeland had degraded extensively for recent 28 years; and (2) the immigrant families were mainly composed of the old, with little or no livestock. What's more, the percentage of immigrant households that share one rangeland certificate with parents or brothers in the immigrant family was 54.5%. Therefore, it is hard to greatly decrease the overgrazing degree through eco- immigration with those previous characteristics of eco- immigrant family structure.  相似文献   

15.
The number of people living in wildfire-prone wildland–urban interface (WUI) communities is on the rise. However, no prior study has investigated wildfire-induced residential relocation from WUI areas after a major fire event. To provide insight into the association between sociodemographic and sociopsychological characteristics and wildfire-related intention to move, we use data from a survey of WUI residents in Boulder and Larimer counties, Colorado. The data were collected 2 months after the devastating Fourmile Canyon fire destroyed 169 homes and burned more than 6,000 acres of public and private land. Although this study is working with a small migrant sample, logistic regression models demonstrate that survey respondents intending to move in relation to wildfire incidence do not differ sociodemographically from their nonmigrant counterparts. They do, however, show significantly higher levels of risk perception. Investigating destination choices shows a preference for short-distance moves.  相似文献   

16.
Early-warning indicators of rangeland health can be used to estimate the functional integrity of a site and may allow sustainable management of desert rangelands. The utility of several vegetation canopy-based indicators of rangeland health at 32 Great Basin rangeland locations was investigated. The indicators were originally developed in rangelands of the Chihuahuan Desert. Soil resources are lost through wind and water-driven erosion mainly from areas unprotected by plant canopies (i.e. bare soil). Study sites in Idaho had the smallest bare patches, followed by sites in Oregon. The more arid Great Basin Sagebrush Zone sites in Utah had the largest bare patches. Several vegetational indicators including percent cover by vegetation, percent cover by life-form, percent cover by sagebrush, and percent cover by resilient species were negatively related to mean bare patch size and are potential indicators of Great Basin rangeland condition. Plant community composition and the range of bare patch sizes were different at sites in the three locations in Idaho, Oregon and Utah. Therefore, expected indicator values are location specific and should not be extrapolated to other locations. The condition of study sites were often ranked differently by different indicators. Therefore, the condition of rangeland sites should be evaluated using several indicators.  相似文献   

17.
Livestock grazing is the most common use of rangelands, and overgrazing by domestic livestock has stirred much debate concerning the continued use of public rangelands for livestock production. With the increase of wildlife-related enterprises on south Texas rangelands, there are little data available on the compatibility of livestock and wildlife management and in particular the effects of livestock grazing on plant communities in the semi-arid portions of the western South Texas Plains. The objective of this study was to compare forb diversity and density on rangelands subjected to various grazing under a high-intensity, low-frequency grazing system and nongrazed rangelands under controlled conditions. Four rangeland sites that were moderately grazed during the dormant season and 4 rangeland sites receiving long-term deferment from grazing were selected on the Chaparral Wildlife Management Area, Dimmit and La Salle Counties, Texas. Forb density was estimated with 20×50 cm2 quadrats during early spring 2000 and 2001. Forb diversity was greatest on grazed sites. Important annuals such as hooker plantain (Plantago hookeriana) and Rough buttonweed (Diodia teres) were more prevalent on grazed sites. Lazy daisy (Aphanostephus spp.) was more frequently encountered on nongrazed sites. Golden dalea (Dalea aurea), a beneficial perennial, was more common on grazed sites. Long-term deferment from livestock grazing appears detrimental to forb communities. A high-intensity, low-frequency grazing system utilizing moderate stocking rates employed during the dormant season is recommended for enhancing forb diversity and abundance.  相似文献   

18.
藏北高山嵩草草甸植被和多样性在沙漠化过程中的变化   总被引:3,自引:0,他引:3  
为确定沙漠化对高山嵩草草甸植被组成、结构和物种多样性的影响,了解高寒区草甸沙漠化的原因,选择西藏那曲安多县南部沙漠化严重区域为调查区,按照沙漠化的不同程度设置样地,系统调查了轻度、中度、重度和极重度沙化草甸的植被变化,结果表明:中度、重度和极重度沙化区的植被与轻度沙化草甸有显著的差异;在中度和重度沙化区,高寒草甸的建群种高山嵩草已被家畜不喜食或更具抗性的植物种所取代,而在极重度沙化的流动沙丘上无植被生长;从过牧的退化草甸到半流动、流动沙丘,植物种多样性呈显著的降低趋势。轻度沙化草甸物种数、个体密度和丰富度指数最多;中度沙化草甸的Shannon\|Wiener指数和均匀度指数最大,而优势度指数最小;在沙化过程中,高寒草甸的植被盖度显著下降,地上生物量也在下降,虽然轻度、中度和重度沙化草地的地上生物量显著高于极重度沙化区,但前者之间却无显著差异。地下根系生物量也呈显著下降的趋势。过牧是造成高山嵩草草甸沙化的主要原因。  相似文献   

19.
Understanding the environmental factors that influence spatial patterns of rangeland wildfires facilitates both fire and land management decisions. I used discriminant analysis to examine ignition frequency of lightning-initiated fires in grass-dominated communities in the Intermountain West between 1980 and 1994, then mapped regional fire frequencies to illustrate spatial patterns. Two canonical discriminant functions effectively separate groups of high, medium, and low ignition frequencies, based on climate conditions and fuel characteristics. Regions of highest frequency tend to have large elevational differences, more mesic climates, and less annual grass cover. Spatial patterns of ignition frequencies tend to reflect local topography, with higher frequencies west of 119° W. Expansion of exotic annual grasses throughout the region may be reducing differences in ignition frequency between regions of highest and lowest frequency.  相似文献   

20.
The infestation rate of termites in the Yabello rangeland, caused by both climatic and human factors, is of interest at certain times. This study was conducted in order to evaluate the impact of termites and determine appropriate management measures in the study area. Data was collected from three kebeles of the Yabello district (Dida Tuyura, Danbal-Waccu and Arero), the selection of which was dependent on the extent to which the termites had spread. A field survey method and semi-structured questionnaires were used for 40 community representatives from each of the selected kebeles. A total of 120 community representatives were interviewed and the interviews were supported by direct observations and informal discussions to understand the impact of termites on rangeland degradation, and to explain the trends. Historical background data of termite infestation rates in the study area was collected and evaluated .In addition to the direct impact caused by termites on forage products, buildings and crops, the linkages of termites with the environment and management mechanisms were identified. Yabello rangeland has often been under termite infestation stress and problems are increasing at an alarming rate. So in order to minimize the impact of termites on rangeland degradation identification of exact termite species and take appropriate management together with the community knowledge and scientific management system was recommended.  相似文献   

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