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1.
Rangeland degradation by livestock threatens several restricted-range species, but is largely overlooked by conservation biologists. The Sidamo lark Heteromirafra sidamoensis , confined to the Liben Plain grassland in southern Ethiopia, is critically endangered by bush encroachment, permanent settlement and agricultural conversion. Its global range was previously estimated at 760 km2, but in 2007–2008 available habitat covered<35 km2. Density estimates from multi-model inference analysis of distance transect data provided a global population estimate of 90–256 adults (possibly with a serious sex-ratio bias towards males). Logistic regression models of habitat selection showed that males preferentially occurred in areas of grassland with greater cover of medium-length grass (5–15 cm), less cover of bare ground and fewer bushes. Habitat transects extending outward from its core range revealed massive and rapid bush encroachment, corroborating information from semi-structured interviews. The survival of both local Borana pastoralism and this species – mainland Africa's likeliest first avian extinction – depends on restoring seasonal patterns of grazing, resisting agricultural conversion of grasslands, reversing fire suppression policies and clearing bush.  相似文献   
2.
ABSTRACT Traditionally, seasons for animals have been designated based on single external variables such as climate or plant phenology, rather than an animal's response to the dynamic environments within which it lives. By interpreting a rate of movement function of cumulative movement through time we established a method that distinguishes transitions between behaviors limited by winter habitat conditions from those present during summer. Identification of these time periods provides temporal definition to subsequent home-range analyses and use-availability comparisons. We used location data from 32 Global Positioning System-collared female moose (Alces alces) to demonstrate the method. We used model selection (Akaike's Information Criterion) to differentiate between candidate rate of movement response curves. Of 32 moose, 29 clearly conformed to an annual movement pattern described by a logistic curve, with increased rates of movement in summer compared to winter. Conversely, 3 aberrant individuals did not alter their movement rate through the year and were best fit with a linear response curve. The seasonal rate of movement model we developed suggests an average summer period of 122 days (median = 119 days, range = 96–173 days) for moose in northwestern Ontario, Canada. The rate of movement model we applied to individuals indicated 1 May as the median date for the winter-summer transition (range = 2 Apr–24 May), and the median transition from summer to winter was 25 August (range = 1 Aug–23 Oct). Wide variation in timing and duration of summer and winter seasons among individuals demonstrates potential failure of the single external variable approach to capture the suite of factors potentially influencing animal behaviors. By plotting cumulative distance moved throughout the year, we elucidated individual variation in response to known and unknown variables that affect animal movement. Accounting for variability among individuals in designation of biologically significant temporal boundaries is critical to delineation of seasonally important habitats for conservation and sustainability of healthy wildlife populations.  相似文献   
3.
Transhumant herding of cow-yak hybrids is a specialization of Helambu Sherpa villagers living at altitudes between 7,000– 11,000 feet on the southern slopes of the Himalayas. Hybrids are ideally suited for the climate at this altitude, producing large quantities of rich milk for butter production. Focused on a village in east- central Nepal, this paper documents a shift by some families between 1971– 1989 from the longstanding pattern of herding hybrids to an alternative pattern of producing them. This involves learning to manage yak, establishing new transhumance routes, a switch from dairying to livestock production, and a variety of economic, environmental, and social repercussions. The two types of herding systems are described, and possible causes for the shift are discussed within the context of the economic options available to people in this environment. A special emphasis is placed on the flexibility of options that is both necessary and possible with transhumant agropastoralism as practiced by middle and high-altitude Himalayan peoples.  相似文献   
4.
The evolution of Spanish landscapes through history is mainly a story of deforestation. Through time, exploitation of natural resources increased to cope with the requirements of more and more complex civilizations. In this work, a review of how the Spanish forests were influenced by human activities and their changes is provided. Forests were cleared for mining, charcoal, shipbuilding and caulking. The most fertile lands were converted into cultivation and more productive cultivars were introduced. Mobile livestock, in particular sheep, became widespread, and with it the burning of wooded land to produce pastures. Woods were privatized through a series of disentailments. All these factors have occurred during the history of Spain, linked to profound changes in the landscape and vegetation. Not until the beginning of the 20th century were real efforts devoted to invert the trend to deforestation inherited from the negative woodland management of previous centuries.  相似文献   
5.
Ten years after the large-scale tsetse control campaigns in the important cattle rearing areas of the Faro and Deo Division of the Adamaoua Plateau in Cameroon, the seasonal distribution and abundance of tsetse flies (Glossina spp.) were determined. During a period of 12 consecutive months (January-December 2005), the tsetse population was monitored along four trap transects consisting of a total of 32 traps and two flyround transects traversing the study area, which comprised the tsetse-infested valley, a buffer zone and the supposedly tsetse-free plateau. Throughout the study period, a total of 2195 Glossina morsitans submorsitans and 23 Glossina tachinoides were captured in the traps and 1007 G. m. submorsitans (78.8% male flies) were captured along the flyround transects. All G. tachinoides and almost all G. m. submorsitans were captured in the valley. Five G. m. submorsitans were captured in traps located in the buffer zone, whereas no flies were captured in traps located on the plateau. The index of apparent abundance (IAA) of G. m. submorsitans was substantially higher in the areas close to game reserves. In the remaining part of the valley, where wildlife is scarce and cattle are present during transhumance (dry season), the IAA of tsetse was substantially lower. In this part of the valley, the abundance of tsetse seemed to be associated with the presence of cattle, with the highest IAA during transhumance when cattle are present and the lowest apparent abundance during the rainy season when cattle have moved to the plateau. It is concluded that the distribution of tsetse in a large part of the valley undergoes substantial seasonal changes depending on the presence or absence of cattle. The repercussions of those findings for the control of tsetse in the valley and the probability of reinvasion of the plateau are discussed.  相似文献   
6.

Aims

Once widely used across Europe, grazing of hay meadows is now a rare agricultural practice that is mainly applied in rural regions with maintained traditional agriculture. In this review, we examine the knowledge on grazing hay meadows in the Carpathian Mountains, including its historical distribution, implementation and timing, potential impacts on grassland productivity and biodiversity, and implications for grassland conservation and restoration.

Location

The Carpathian Mountains (43.8–50.1°N, 16.9–27.1°E).

Methods

We conducted a literature review including biological, ecological, agricultural, ethnological, and historical sources.

Results and Conclusions

In each of the seven farming systems that existed in parallel in the Carpathian Mountains before agricultural intensification, grazing of hay meadows was applied regularly. Spring, autumn, and occasionally summer grazing, along with corralling and manuring of hay meadows, were integral parts of these systems, adapted to the seasonal movement of dairy farms across various agroecosystems. The data reviewed provide insight into the role of animals in hay meadow management, as well as how the breakdown of these historical farming systems is impacting local biodiversity, the economy, and the community. According to the literature sources, grazing hay meadows has numerous positive impacts on grassland biodiversity, including suppressing fast-growing competitors, reducing the accumulation of litter, increasing the availability of germination gaps, dispersing seeds through zoochory, supporting ground-nesting birds through later mowing, and promoting the regeneration of plants from seeds. From this perspective, the combination of mowing and grazing can be considered a promising tool in current grassland conservation and restoration efforts.  相似文献   
7.
In this paper, we present the results of four pollen diagrams obtained from the northeastern coast of the Iberian Peninsula. These data, together with a set of 11 radiocarbon dates, allow us to make some suggestions about human activity in this area mainly during the last 6000 years. We have established four main stages of this activity. Phase I (7000–3000 B.P.) shows some sporadic human clearance without qualitative and/or quantitative changes inside the natural woodland, except for slight oscillations in AP values. These clearances are synchronous with Neolithic and Bronze Age settlements. Phase II (3000–1500/1300 B.P.) demonstrates a different human action on the landscape along the Catalan coast. Sampling sites located in rich agricultural plains and close to urban centres show continuous woodland clearance during the Iberian period and especially during Roman times. In contrast, at boring sites far from these towns, the irregular and sporadic woodland disturbances continue, although these become more common. Phase III (1500/1300–850 B.P.) shows further woodland clearance fires along the coast. Pollen, archaeological and historical evidence allow us to relate this to the introduction of grazing in the coastal area, connected with seasonal transhumance between the littoral and mountain regions. Phase IV (850–300/150 B.P.) is characterised by the final clearance of woodland and the development of olive farming. During this phase the agrarian Mediterranean landscape was definitively formed.  相似文献   
8.
Cattle transhumance has been practiced since colonial times in Mapuche communities of northwestern Patagonia, which travelled seasonally along the Andean valleys from arid lands towards temperate forests. In this study, we analyzed how this migratory practice affects the abundance and variety of wild edible plants utilized by the Mapuche community of Paineo. Patterns of use for those who practice transhumance were compared with those who do not utilizing ecological variables. Gender and age were also evaluated. The Paineo people collect wild plants in 3 different gathering sites: the A. araucana forest, the Travesía, and their dwelling surroundings. However, those who practice summer transhumance utilize a more diverse variety and a tan greater quantity of wild edible forest plants than those who do not. Moreover, the nutritional value of plants collected by transhumants is greater than those used by non-transhumants. Men practice summer cattle transhumance in a greater proportion than do women and consume significantly more wild edible plants. In contrast, plants from their dwellings and from the Travesía are used in a similar way by both sexes. It was observed that the elderly do not presently participate in transhumance. Our results illustrate a change in wild plant knowledge influenced by the transformation of the summer transhumance pattern.  相似文献   
9.
A significant change in the geography of livestock raising over the past 30 years is the southerly movement of FulBe herds into the humid Sudanian and Guinean savannas of West Africa. The literature suggests that the severe droughts of the early 1970s and mid-1980s were the driving force behind this southern expansion of mobile livestock raising. The conventional view is that drought forced herders to seek greener pastures to the south, an area that zebu cattle have previously avoided because of the presence of tsetse flies, the vector of animal sleeping sickness (trypanosomiasis). This “sudden push” hypothesis places Sahelian herds in savanna pastures in a matter of a 1–3 years. This stimulus-response model runs counter to our observations and understanding of the social and ecological processes influencing FulBe herd movements. We challenge the “sudden shift” thesis at the regional scale by arguing that the southerly expansion of FulBe herds has proceeded according to a more complex temporal frame that includes generational, biological, and social historical timeframes and periodicities. We distinguish between short-term shifts (“test movements”) and more permanent shifts (“migration movements”). These mobility patterns are linked to contingent factors such as cattle diseases, drought, and political instability, as well as to more structural and adaptive features such as the establishment of social networks, herding contracts, and cattle cross-breeding. Shifts in livestock ownership and the social differentiation among herders are important variables for understanding changes in herd movements. We conclude that the permanent shift of herds to the humid savannas of West Africa has been preceded by a series of social and agroecological adjustments that operate on decadal and generational time scales.
Matthew D. TurnerEmail:
  相似文献   
10.
Existing transhumance practices in the Gredos Mountains are studied and the origin, destination, number of livestock, livestock raiser characteristics, and environmental variables of winter and summer pasture areas and drovers roads are analyzed. The important ecological, economic, and cultural role of transhumance is emphasized and attention is drawn to the need for its support and conservation.  相似文献   
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