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1.
1. Dung beetles perform relevant ecological functions in pastures, such as dung removal and parasite control. Livestock farming is the main economic activity in the Brazilian Pantanal. However, the impact of cattle grazing on the Pantanal's native dung beetle community, and functions performed by them, is still unknown. 2. This study evaluated the effects of cattle activity on dung beetle community attributes (richness, abundance, biomass, composition, and functional group) as well as their ecological functions (dung removal and soil bioturbation) in the Pantanal. In January/February 2016, dung beetles were sampled and their ecological functions measured in 16 sites of native grasslands in Aquidauana, Mato Grosso do Sul, Brazil, 10 areas regularly grazed by cattle and six control ungrazed areas (> 20 years of abandonment). 3. In all, 1169 individuals from 30 species of dung beetles were collected. Although abundance, species richness, and biomass did not differ between grasslands with and without cattle activity, species composition and functional groups differed among systems. Large roller beetles were absent from non‐cattle grasslands, and the abundance, richness, and biomass of medium roller beetles was higher in those systems. 4. Despite causing changes in species/functional group composition, the results of this study show that a density compensation of functional groups in cattle‐grazed natural grasslands seems to have conserved the ecological functions (dung removal and soil bioturbation), with no significant differences between systems. 5. Therefore, these results provide evidence that cattle breeding in natural grasslands of the Brazilian Pantanal can integrate livestock production with the conservation of the dung beetle community and its ecological functions.  相似文献   

2.
Abstract. In recent decades, cattle ranchers of the Pantanal of Mato Grosso, Brazil, have pointed to the accelerated spread of several herbaceous and woody plant species that invade natural and artificial pastures (campos). It has been speculated that overgrazing by an increasing number of cattle, lack of grazing in abandoned areas, or large‐scale changes in environmental conditions may be the reason for this invasion. This study focuses on ecological and ecophysiological aspects of Vochysia divergens (cambará), a flood‐tolerant tree that began spreading in the Pantanal during the last 30 years and is considered a very aggressive invasive plant. The study shows that the spread of cambará can be related to natural multi‐years wet periods. During multi‐years dry periods the species is reduced by the increasing impact of fires in the Pantanal. This points to the great importance of multi‐years climatic events on the vegetation cover of the Pantanal and indicates a very dynamic development in plant communities.  相似文献   

3.
The Pantanal floodplain of southwestern Brazil, with its mosaic of marshes,seasonally flooded savannas, woodlands and forests, is known as one of thewildlife hotspots of South America. The region harbors a rich mammal fauna andis a stronghold for a number of mammal species; however, still very few thoroughmammal surveys have been conducted in the Pantanal. This is the first mammalsurvey from the southeastern part of the region. An intensive,three-month study of the medium to large, non-volant species wasconducted at a location in the upper Rio Negro Basin, Aquidauana region, MatoGrosso do Sul. Thirty species of mammals were recorded, including 5 xenarthrans,1 primate, 10 carnivores, 7 ungulates and 5 caviomorph rodents. It was possibleto analyze the field biology of many of the species to a level not previouslypublished for the Pantanal. Recommendations are given for camera trapping in thePantanal and the Amazon. Finally, the effects of intensive cattle ranching onconservation in the Pantanal are discussed.  相似文献   

4.
Passive acoustic monitoring coupled with automated signal recognition software has been widely used in recent years as an effective and affordable tool for wildlife monitoring and to combat illegal activities within protected areas. Here, we evaluate this technique to monitor the patterns of illegal cattle occurrence in the Brazilian Pantanal over a complete annual cycle. We aim to provide one of the first assessments of the performance of automated signal recognition software to detect ungulates. Cattle occurrences reached their maximum during the end of the dry season when lowland areas provide excellent pastures for cattle. In contrast, cattle occurrences were very low during the rainy season when the study area was seasonally inundated. Automated software was an efficient tool that was able to detect approximately three-quarters of cow calls within the recordings. Passive acoustic monitoring can be used to direct patrols to areas where illegal activities, such as cattle and poaching or logging, have been confirmed, which could be a method that would be especially well suited for remote areas, such as tropical forests. Future studies should evaluate whether there is a relationship between cattle grazing intensity and its associated impacts on wildlife and flora. Rapid advances in automated recognition and the recent development of low-cost recorders foresee a new era of acoustic ecology for improved conservation in the short term.  相似文献   

5.
The hydrology of the Brazilian Pantanal, part of the largest humid tropical area on the planet, follows the rhythm of seasonal floods. The traditional movement of cattle herds in the southern Pantanal is defined by these seasonal flooding patterns, which determine the availability and quality of native-grass pastures throughout the year. Extreme hydrological events, such as prolonged droughts and intense floods, can impact the management of cattle in this region, preventing access to, circulation within, and occupation of some grazing areas. This study aims to analyze the spatial and temporal variability of precipitation, the river levels in this region from 1974 to 2012, and assessed the effects on the evolution of local beef cattle stocks. We integrated the spatiotemporal variability of precipitation and river levels for six gaging stations and standardized these variables using standard deviation and linear trends at annual and seasonal scales. Additionally, we integrated the results with an analysis of the livestock production within the region’s municipalities. Regional precipitation was highly variable, including an almost decadal oscillation, with positive trends in parts of the 1970s and 1980s and a negative trend since the 1990s. River levels in the northern portion of the basin and in the Paraguay River corresponded to those dynamics while presenting marked anomalies. Simultaneously, river levels in the eastern Pantanal changed from negative to positive anomalies, which were more intense in wet months. Both the eastern and western patterns reflected the occurrence of extreme El Niño–Southern Oscillation events and other large-scale climatic patterns. In intra-annual terms, the variability of the river levels during the flooded months at four of the six gaging stations studied suggests an early onset or delay of the flood season, as well as positive anomalies in the ebbing months and in the southeast. Given the lags in flow between different rivers in the region, this behavior draws attention to dam construction and intensification of localized flooding in the southern areas, which may impact everyday life and cattle management. For example, from 2009 to 2012, two severe droughts and an extreme flood significantly impacted livestock numbers in the region. Overall, herd numbers decreased (increased) in humid (dry) periods, including a reduction of over 1 million head during the flood of 1973–1974. The differential level patterns at annual, wet season, and dry season between the eastern and western sides of the Pantanal modulate the livestock activities, where the strong negative anomalies of the levels along the eastern side seem to force the diminution of beef cattle stock at local regions in different intensities in annual scale. This reinforces the effects of climate variability and extreme hydrological events on the management and dynamics of the beef cattle industry and market in Brazil.  相似文献   

6.
Anthropogenic activity, such as conversion and degradation of habitats, is causing global biodiversity declines. However, our understanding of how local ecological communities are responding to these changes taxonomically and functionally is still limited. The effects of the replacement of native by introduced pastures on biodiversity are some of those examples with limited understanding. Here, we sampled dung beetles in native and introduced pastures using standardised sampling protocols during the dry and rainy seasons in the Brazilian Pantanal. We used multifaceted β-diversity partitioning of taxonomy-, abundance- and trait-based approaches to evaluate spatial (i.e. between pasture types) and temporal (i.e. between seasons) patterns of dung beetle changes in composition, abundance and species traits. Spatially, we found no effects of pasture type, season and their interaction on taxonomy-based β-diversity and its components. For abundance-based β-diversity and its components, pasture type had effects on both Bray-Curtis dissimilarity and balanced variation in abundance. Higher values of both metrics were found in native pastures. For functional-based β-diversity, Sorensen dissimilarity with higher values in the dry season, while pasture type also had an effect on functional nestedness, where higher values of functional nestedness were found in introduced pastures. Seasonally, we also found no effects of pasture type, season and their interaction on taxonomy-based β-diversity and its components. However, pasture type had effects on Bray-Curtis dissimilarity, with higher values found in introduced pastures. No effects on balanced variation in abundance and abundance gradients were found. Pasture type influenced the functional turnover, but not functional dissimilarity or nestedness. Higher values of functional turnover were found in native pastures. In summary, we demonstrate that the type of pastures and climatic seasonality have effects on abundance- and functional- but not on taxonomy-based β-diversity patterns of dung beetles in the Brazilian Pantanal.  相似文献   

7.
Livestock trails frequently evolve in pastures when plant growth or establishment cannot keep pace with vegetation disturbance. In some instances, man-made trails are established in rangeland settings to encourage uniform use of forages or facilitate livestock passage through dense vegetation or across rugged terrain. A long-term assumption has been that livestock establish pathways of least resistance between frequented areas of their pastures, but this hypothesis has never been tested. We mapped cattle trails in three 800+ ha pastures with global positioning units. A geographic information system (GIS) helped quantify characteristics of trails and the landscape and was used to plot least-effort pathways between water sources and distant points on selected trails in the pastures. Characteristics of the cattle trails and least-effort pathways were compared to test the hypothesis that cattle develop least-effort routes of travel in rugged terrain. The mean slope of the three pastures was 13.5%, and the average slope of the topography traversed by the cattle trails was 8%. The slope of the trails was reduced to 5.2% by selection of cross-slope routes. When we compared the characteristics of 10 selected cattle trails and least-effort pathways generated by our GIS, the cattle trails were 11% shorter (P=0.046) than the least-effort pathways, and the topography traversed by cattle had a gradient about 1% less than the least-effort pathways (P=0.02). The slope of the selected trails (5.5%) and pathways (5.6%) were similar (P=0.74), however. Analyses of values extracted from cost surfaces indicated that, on the average, 183 units of effort were needed to traverse the trails and 170 units of effort expended to traverse the least-effort pathways (P=0.07). These data support the hypothesis that cattle establish least-effort routes between distant points in rugged terrain and suggest that GIS software may be useful in designing systems of livestock trails in extensive settings.  相似文献   

8.
Hart  Richard H. 《Plant Ecology》2001,155(1):111-118
Shortgrass steppe rangeland near Nunn, Colorado, USA, has been lightly,moderately, or heavily grazed by cattle, or protected from grazing inexclosures, for 55 years. Plant species biodiversity and evenness were greatestin lightly- and moderately-grazed pastures. Both pastures weredominated by the warm-season shortgrass Boutelouagracilis, but the cool-season midgrasses Pascopyrumsmithii and Stipa comata contributedsignificantly to biomass production on the lightly-grazed pasture, asthey did in the exclosures. Diversity was least in the exclosures, which werestrongly dominated by the cactus Opuntia polyacantha.Buchloë dactyloides, another warm-seasonshortgrass, and Bouteloua gracilis were co-dominantsunder heavy grazing, and diversity was intermediate. Plant community structureand diversity were controlled by selective grazing by cattle and soildisturbance by cattle and rodents. Shortgrass steppe moderately or heavilygrazed by cattle was similar to and probably as sustainable as steppe grazed formillenia by bison and other wild ungulates.  相似文献   

9.

Maximizing biodiversity persistence in heterogeneous human-modified landscapes is hindered by the complex interactions between habitat quality and configuration of native and non-native habitats. Here we examined these complex interactions considering avian diversity across 26 sampling sites, each of which comprised of three sampling points located across a gradient of disturbance: core native habitat fragment, fragment edge, and non-native adjacent matrix. The 78 sampling points were further nested within three neotropical biomes—Amazonia, Cerrado and Pantanal—in central-western Brazil. Matrix type consisted of cattle pastures in the Amazon and teak plantations in the Pantanal and Cerrado. We considered the interactive effects of (1) disturbance-context: fragment core, edge and adjacent matrix, (2) matrix type: tree plantation or cattle pastures, both subject to varying land-use intensity, and (3) native habitat configuration (fragment size, shape and isolation) on bird species richness, abundance and composition. Based on point-count surveys, we recorded 210 bird species. Bird species richness and abundance declined across the disturbance gradient, while genus composition only differed within the adjacent matrix, particularly cattle-pastures. The effect of native habitat area was positive but only detected at fragment edges. Overall bird diversity increased at sites characterized by higher availability of either relict trees within pasture landscapes or old-growth trees within teak plantation landscapes. The core of native fragments played a primary role in ensuring the persistence of bird diversity, regardless of fragment size. In contrast to pastures, tree plantations likely harbour a higher proportion of forest-dependent species while bird diversity can be further enhanced by reduced management intensity in both matrix types. Strategies to maximize avian persistence should not only include retaining native habitats, but also maximizing the size of core native habitats. Likewise, more structurally complex matrix types should be encouraged while maintaining low levels of land-use intensity.

  相似文献   

10.
The Pantanal is a large savanna wetland (138,183 km2 in Brazil), important for its wildlife, fed by tributaries of the upper Paraguay River, center of South America (Brazil, touching Bolivia and Paraguay). Uplands are plateaus (250-1,200 m high, 215,000 km2 in Brazil) and flatland is the Pantanal (80-150 m high, 147,574 km2 in Brazil). Rivers are slow moving when they meet the flatland (slope 0.3-0.5 m/km east-west; 0.03-0.15 m/km north-south), periodically overflowing their banks, creating a complex seasonal habitat range. Recurrent shallow flooding occupies 80% of the Pantanal; during the dry season flooded areas dry up. Fluctuating water levels, nutrients and wildlife form a dynamic ecosystem. A flooding regime forms distinct sub-regions within the Pantanal. A mammal survey was carried out in the sub-region of the Rio Negro from April, 2003 through March, 2004 to study the diversity and abundance of terrestrial mammals during the dry and flooding seasons. A total of 36 species were observed in the field. The capybara Hydrochaeris hydrochaeris was the most frequent species, followed by the crab-eating-fox Cerdocyon thous and the marsh deer Blastocerus dichotomus. The highest abundance of species was observed during the dry season (August and September), when there is a considerable expansion of terrestrial habitats, mainly seasonally flooded grassland. Animal abundance (in terms of observed individual frequencies) varied during the dry and wet seasons and the seasonally flooded grassland was the most utilized habitat by mammals in the dry season.  相似文献   

11.
The Pantanal is the largest Neotropical seasonal freshwater wetland on Earth. Extensive livestock production has been the dominant economic land use activity of the Pantanal, where approximately 80 % of the land is occupied by native and introduced pastures. However, the impact of native pasture conversion into introduced pasture on the biodiversity of this biome is little understood. Here we evaluate the effect of native pasture to introduced pasture conversion on dung beetle communities. We sampled dung beetles in July 2011 (dry season) and January 2012 (rainy season), at four native pasture sites and four introduced pasture sites in Aquidauana, Mato Grosso do Sul, Brazil. The sampling was carried out using pitfall traps baited with three different bait types: carrion, cattle dung, and human feces. We sampled 7086 individuals, belonging to 32 species of 16 genera and six tribes of dung beetles. The abundance was similar among the pasture types. However, a higher species richness was found on the native pasture. Species composition also differed between the two pasture types in each sampling season. Additionally, the dominant functional guilds were different in the two landscapes. The result shows that the conversion of native grasslands into introduced pasture results in a decrease of species number and changes in species composition. These findings highlight the importance on native pasture to the conservation of dung beetle biodiversity in this ecosystem.  相似文献   

12.
Infanticide is an antagonistic behavior that may provide an evolutionary benefit for the perpetrator. Cases of infanticide have rarely been reported in Neotropical carnivores. The objective of this study was to provide empirical evidence of infanticide in a local jaguar (Panthera onca) population in the Brazilian Pantanal. We present infanticide data from opportunistic sampling. Each month, from 2013 to 2015, we monitored pastures for evidence of livestock carcasses. A remotely triggered camera trap was placed at encountered fresh cattle carcasses. Through this monitoring, two cases of infanticide were recorded. Both cases occurred in close proximity to a cattle carcass, a large prey item that may attract multiple jaguars—including females with cubs around age of weaning—and increase the risk of infanticide. Our observations provide new empirical evidence of jaguar social behavior and intraspecific competitive interactions, potentially driven by locally high population density and resource provision.  相似文献   

13.
The authors sacrificed fifty-five horses originated from the "Pantanal", lowlands in the State of Mato Grosso in two different periods, droughty period and flooded and they described for the first time the Dictyocaulus arnfieldi in Mato Grosso. Relationship between droughty and flooded periods proved not to occur.  相似文献   

14.
The influence of rainfall and initial pasture biomass on growth and dieback of pastures in temporary enclosures over quarterly periods was examined from 1980 to 1985 at Menindee in western New South Wales. Rainfall during the previous 12 months had the most influential effect on biomass of grazed pasture, and accounted for 69% of the variance. During quarterly periods, when the biomass of pasture protected from grazing increased, rainfall accounted for 93% of the variance. For all quarterly periods (whether pasture biomass increased or decreased) current rainfall accounted for 72% of the variance in biomass change (growth minus senescence) and initial biomass accounted for a further 14%. The growth response to rainfall was similar in pastures grazed by a combination of sheep and kangaroos and in those grazed by kangaroos alone.  相似文献   

15.
WINTER FEEDING ECOLOGY OF WIGEON ANAS PENELOPE AT THE OUSE WASHES, ENGLAND   总被引:1,自引:0,他引:1  
Angela  von Känel 《Ibis》1981,123(4):438-449
Investigations on the feeding ecology of Wigeon were carried out in winter 1978–79 at the species' most important inland wintering habitat in Britain. The study area included 287 ha of grassland, about one-sixth of the Washes, which is grazed by cattle and sheep until late autumn. In winter the area is partly or fully flooded. The number of Wigeon increased to 11 200 in January but cold weather in February, with snow and frozen flood water, forced the birds to leave, only 600 staying in the reserve. In March up to 4000 birds were again present. The distribution of the population within the refuge depends on whether the habitat is dry pasture with only a few ponds, partly flooded, fully flooded or covered with snow and frozen flood water. Under dry or slightly wet conditions 98% of the Wigeon were grazing (October to January), while under partly flooded conditions (February and March) 42%, fed on water. With increasing water depth, upending was used by 13%, while 45% of the population moved to the barrier banks, grazing there in March. The feeding method can change within a few hours with increasing water depth. The diurnal activity pattern varies during the wintering period. A lower percentage of morning feeding occurred after flights back from feeding outside the refuge and under frozen conditions. The feeding activity was higher at mid-day with a slight decrease towards dusk. The average diurnal feeding activity was 71% (October to April), with a maximum of 90% in November. Wigeon feed diurnally and nocturnally. During a 24 h period in March they were foraging for 15 h 40 min; by day 81% of the time was spent feeding, while at night only 48%. Standing crop measurements showed that the biomass of green vegetation declined significantly outside enclosures due to Wigeon usage. Pasture land should be grazed at different intensities by cattle and sheep before the arrival of the ducks. Inland reserves should include such pasture together with some standing water where the birds are undisturbed. The use of inland pastures can compensate for the loss of coastal habitats.  相似文献   

16.
《Ecological Engineering》2005,24(4):391-401
The Pantanal, a large and still rather pristine wetland in the center of the South American continent, is becoming increasingly threatened by large development programs. Agroindustries and reservoirs for hydroelectric power generation in the catchment area modify discharge pattern and sediment load of the tributaries, plans for canalization of the Paraguay River (hidrovia) are putting in risk the natural flood regime of large areas inside the Pantanal, and attract industries with high potential for environmental pollution, economic pressure on the traditional cattle ranchers accelerates the transformation of natural vegetation into pasture, etc. These activities negatively affect habitat and species diversity and scenic beauty but also the hydrological buffer capacity of the Pantanal. The article summarizes the ecological conditions of the Pantanal, discusses commercial and non-commercial values of the area, describes constraints for the development of intensive agriculture and cattle ranching, and discusses development alternatives. Considering the low density of human population inside the Pantanal, it can be concluded that development pressure on the Pantanal arises mostly from pressure groups outside the area that will also mostly benefit from the economic return of the development projects. Low density of human population would still allow the application of economically viable and environmentally friendly development alternatives that maintain and sustainably manage one of the largest wetlands in the world.  相似文献   

17.
Landscape epidemiology analyses how environmental characteristics influence pathogen transmission between hosts of one or several species, by inducing constraints on space use by hosts, and/or on pathogen survival in the environment. Here, we analysed how environmental variables could be associated with the Mycobacterium bovis concomitant infection in both cattle and badgers, in an area of south-western France. We defined circular spatial units (500 and 1000 m radiuses) centred on 113 setts of trapped badgers and including cattle pastures. The characteristics of spatial units where only one species had been found infected were compared with the ones where both cattle and badgers had been found infected. A multivariate logistic model was used to analyse the association between concomitant infection in both species and three groups of variables describing landscape, animal population and terrain features of spatial units. The terrain ruggedness index of pastures and the percentage of sand in their soil were positively associated with the odds of concomitant infection in cattle and badgers in the spatial units. The number of neighbouring badger groups was negatively associated with the odds of concomitant infection (spatial units of 1000 m radius), whereas the number of crop parcels was positively associated with the odds of concomitant infection (spatial units of 500 m radius). These results suggest that terrain features, badger population structure and food availability may influence the spread of M. bovis infection between badgers and cattle, leading to concomitant infection of both species.  相似文献   

18.
Grasslands are the main source of feed for cattle in Argentina. Standing dead biomass accumulation threatens efficient resource use. The effect and timing of high impact grazing by cattle as a management tool to remove excess standing dead biomass was studied in grasslands of North Eastern Argentina. High impact grazing (HIG) was introduced monthly on adjacent paddocks over the course of the year and its effects were studied for 12 months following the treatment. Dynamics of biomass re-growth and accumulation of green and standing dead biomass were studied. HIG generally improved the green to total biomass ratio and reduced the overall biomass in the paddocks. Strong seasonal dynamics in the biomass growth rates strongly influenced the effects of timing of the HIG. All sub-plots subjected to HIG showed a growth pattern anti-cyclic to control, with an active growth phase during autumn when the biomass in the control sub-plots decreased. Best results in terms of standing dead biomass reduction and dead to green biomass ratios were achieved after HIG in winter. HIG in autumn, however, reduced fodder availability and reduced next year's grassland's productivity. We propose strategically (carefully) timed HIG not only as an alternative method to reduce standing dead biomass, but also as a pathway to sustainable intensification by providing green forage at levels equal or even higher than those achieved under continuous traditional grazing.  相似文献   

19.
Classification and ordination of plant formations in the Pantanal of Brazil   总被引:1,自引:0,他引:1  
Pinder  Laurenz  Rosso  Sergio 《Plant Ecology》1998,136(2):151-165
Classification and ordination of plant formations are presented for a seasonally flooded plain of the Brazilian Pantanal. Phytosociological data were collected on 10 physiognomically distinct formations during the rainy, flood, and dry seasons. The degree of association among plant species was measured with Jaccard similarity index, and both Jaccard similarity index and Bray Curtis distance index were employed to classify sample units into similar groups. The ordination of plant species and sample units were performed with Correspondence Analysis. Four groups of plant formations were significantly distinct on a quantitative basis: marsh ponds/waterlogged basins, short grasslands, tall grassland/scrub, and forest-edges. These formations were ordered along a gradient of topographic relief from depressions with permanent standing water (marshes) through flats subject to seasonal flooding (grasslands and scrub) and mounds of sandy soil above the flood level (forests). Although hydroperiod appears to be one of the most important variables, the distribution of plant species within wetlands is most probably explained by the interaction of many additional factors. A few plant species could be used as indicators of the local hydrological and edaphic conditions, e.g., Eleocharis elegans, Aeschynomene fluminensis, Hydrolea spinosa, and Hymenachne amplexicaulis for marsh ponds, and Caperonia castaneifolia, Diodia kuntzei, and Eleocharis acutangula for waterlogged basins. The procedure presented in this study could be developed as a tool for the inventory and management of the Pantanal and other palustrine wetland habitats.  相似文献   

20.
The financial impact of the first outbreak of Trypanosoma vivax in the Brazilian Pantanal wetland is estimated. Results are extended to include outbreaks in the Bolivian lowlands providing a notion of the potential influence of the disease and an analytical basis. More than 11 million head of cattle, valued at more than US$3 billion are found in the Brazilian Pantanal and Bolivian lowlands. The total estimated cost of the 1995 outbreak of T. vivax is the sum of the present values of mortality, abortion, and productivity losses and treatment costs, or about 4% of total brood cow value on affected ranches. Had the outbreak gone untreated, the estimated losses would have exceeded 17% of total brood cow value.  相似文献   

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