Effects Of Cattle Grazing Research Articles

Cattle Grazing and Vegetation Succession on Burned Sagebrush Steppe

There is limited information about the effects of cattle grazing to longer-term plant community composition and herbage production following fire in sagebrush steppe. This study evaluated vegetation response to cattle grazing over 7 yr (2007–2013) on burned Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis [Beetle & Young] Welsh) steppe in eastern Oregon. Treatments, replicated four times and applied in a randomized complete block design, included no grazing on burned (nonuse) and unburned (control) sagebrush steppe; and cattle grazing at low (low), moderate (moderate), and high (high) stocking on burned sagebrush steppe. Vegetation dynamics were evaluated by quantifying herbaceous (canopy and basal cover, density, production, reproductive shoot weight) and shrub (canopy cover, density) response variables. Aside from basal cover, herbaceous canopy cover, production, and reproduction were not different among low, moderate, and nonuse treatments. Perennial bunchgrass basal cover was about 25% lower in the low and moderate treatments than the nonuse. Production, reproductive stem weight, and perennial grass basal cover were greater in the low, moderate, and nonuse treatments than the control. The high treatment had lower perennial bunchgrass cover (canopy and basal) and production than other grazed and nonuse treatments. Bunchgrass density remained unchanged in the high treatment, not differing from other treatments, and reproductive effort was comparable to the other treatments, indicating these areas are potentially recoverable by reducing stocking. Cover and production of Bromus tectorum L. (cheatgrass) did not differ among the grazed and nonuse treatments, though all were greater than the control. Cover and density of A.t. spp. wyomingensis did not differ among the burned grazed and nonuse treatments and were less than the control. We concluded that light to moderate stocking rates are compatible to sustainable grazing of burned sagebrush steppe rangelands.

Grazing Promotes Bryophyte Species Richness in Seminatural Grasslands

We studied the effects of cattle grazing on bryophyte species richness in Finnish seminatural grasslands and examined if there are differences among bryophyte life-strategies in relation to grazing pressure. We recorded species richness and cover of bryophytes in 420 sample plots located in 21 grasslands. Percentage of bare ground, height of vascular plant vegetation and cover of vascular plant litter were used as proxies for grazing intensity. We also explored the microhabitat preferences of individual species. Species richness of all bryophytes, perennial residents and colonists increased with grazing pressure. As compared with perennials, many species among the colonists had strong affinity to sites with high proportion of bare ground. We conclude that both perennial and colonist bryophytes benefit from grazing in semi-natural grasslands, although the effects of grazing are differently realized in the different bryophyte groups.

Grazing in sagebrush rangelands in western North America: implications for habitat quality for a sagebrush specialist, the pygmy rabbit

Livestock grazing is one of the primary uses of sagebrush rangelands in western North America; therefore, an understanding of the ecological implications of grazing on habitat quality for sagebrush-dependent wildlife is needed to help land managers balance multiple objectives for land use. We studied effects of cattle grazing on components of habitat for an uncommon sagebrush habitat specialist, the pygmy rabbit (Brachylagus idahoensis), which has been petitioned for endangered or threatened status in the USA. We evaluated multiple components of habitat before and after grazing in replicated control and treatment plots in a mesic, high-elevation sagebrush-steppe environment in south-western Montana, USA. We predicted that grazing would decrease the biomass of herbaceous forage, alter security cover, and increase rate of collapse of rabbit burrows, and we expected that these effects would be more pronounced during summer than spring. As expected, cattle grazing reduced the biomass of perennial grasses available to pygmy rabbits after grazing that occurred during either spring or summer, and the biomass of forbs after spring grazing. In contrast, grazing did not markedly influence the functional properties of vegetation related to predation risk or the integrity of rabbit burrow systems. In the context of the stocking rate of the allotments in our study (7.3 acres/Animal Unit Month, 2.95 ha/Animal Unit Month), annual cattle grazing did not seem to markedly change habitat for pygmy rabbits in our study area; however, longer-term and higher intensity grazing might result in more pronounced habitat changes. Understanding the ecological implications of cattle grazing on habitat quality for pygmy rabbits and other sagebrush-dependent wildlife can guide conservation strategies for these species on sagebrush rangelands managed under multiple-use policies.

Continental‐Scale Governance and the Hastening of Loss of Australia's Biodiversity

Against a global backdrop of rapid environmental change, conserving biodiversity poses one of the biggest and most important challenges to society. For this reason, systems of nature reserves have never been more important. Protected areas are under threat in many parts of the world (Mascia & Pailler 2011), but the weakening of protected areas in a rich, developed country with a global reputation for conservation leadership (Harrison 2006) is particularly alarming (Ritchie 2013). Consequently, we are concerned about the recent spate of substantial policy, legislative, and management changes being made by three of six Australian state governments for exploitative uses of national parks—actions that could affect much of Australia and have negative effects on biodiversity.

Effects of grazing on N2O production potential and abundance of nitrifying and denitrifying microbial communities in meadow-steppe grassland in northern China

PurposeThe aim of this study was to investigate the effects of cattle grazing on the nitrous oxide (N2O) production potential from meadow-steppe grassland soil in northern China, and the relationship between cattle grazing and the abundance of different functional microbial genes for potential of N2O emissions. Materials and methodsWe collected soil samples at a depth of 0–20 cm over six times during two plant growing seasons in 2011 and 2012 on a native Leymus chinensis grassland. At each of the six sampling occasions, soil samples were taken from three pairs of the cattle grazed vs. ungrazed plots. We then determined (1) the soil moisture, pH, total carbon and nitrogen, and mineral N (NH4+ and NO3−) content, (2) the potential rates of N2O production from nitrification (NN2O) and from denitrification (DN2O and DN2) using the acetylene inhibition method, and (3) the abundance of the amoA (ammonia monooxygenase) gene of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB), the narG (nitrate reductase) gene and nosZ (nitrous oxide reductase) gene using quantitative real-time PCR (qPCR). The relationship among the changes in the N2O production potential rates, the abundance of microbial functional groups and the soil environment was analyzed using mix effects modeling and structural equation modeling. Results and discussionThe AOA, AOB, narG, nosZ genes and the potential N2O production rate all varied significantly with the season (P < 0.01). Grazing induced an overall reduction in soil moisture (P < 0.05) and soil total N in 2012 (P < 0.05), and a significant increase in the abundance of AOB genes (P < 0.05); but no significant difference between grazing treatments was found on the abundance of AOA, narG and nosZ genes, or on the NN2O and DN2O.Approximately 80% of the variation in NN2O could be explained by the abundance of AOA and AOB genes (P < 0.0001), which in turn was explained by soil NH4+ content and soil moisture; The abundance of narG gene, along with total C, NO3− content and soil moisture, explained 87% of variation in the DN2 (P < 0.0001). The abundance of narG gene was related to the production of N gases from denitrification (DN2O+N2), but not the DN2O. Soil moisture was the best predictor for DN2O. ConclusionsThe abundance of amoA and narG genes are good indicators for the potential nitrification and denitrification rates in the meadow steppe grassland. Soil moisture is the most important factor controlling the N2O emission potential in the meadow-steppe grassland. The grassland soils protected from animal grazing or that under a moderate grazing for five years did not show a significant difference in potential N2O emissions. Our results suggest that grazing induced grassland degradation may not necessarily be associated with a reduction in N2O emissions as reported in other semiarid grasslands in a more arid environment.

Effect of Different Stocking Rates on Deyeuxia angustifolia Bog Meadow in Sanjiang Plain of China

This paper investigated the effects of cattle grazing on herbage production and its nutrient and soil characteristics over the grazing season. The grazing experiment was conducted on Deyeuxia angustifolia Bog meadow grassland established in 2010 in Sanjiang Plain. Four grazing treatments were light grazing (LG), moderate grazing (MG), heavy grazing (HG), and a non-grazed exclosure (CK) with corresponding stocking rates of 0.6, 1.0, 1.4, and 0 AU • hm−2 • month−1, selected as three replications. And then found out the optimum carrying capacity after analyzed the nutrition balance between livestock and grassland. Heavy grazing led to a decline in grassland productivity and soil nutrients. The SOM and the TN content in the soil layer of 0–10 cm were much higher than that in the soil layer of 20–30 cm. More attention should be paid to the nutrient changes in the soil layer of 20–30 cm. Currently, studies showed that the reliable carrying capacity in this type of grassland was 1.0 AU • hm−2 • month−1. Inclusion of rangeland health monitoring and optimum stocking rate into grassland management model could facilitate the sustainable development of the grassland.

Effect of cattle grazing on soil salinity and vegetation composition along an elevation gradient in a temperate coastal salt marsh of Samborombón Bay (Argentina)

Salt marshes of Samborombon Bay (Argentina) have been grazed sporadically at very low stocking rates, but in the last decade, grazing intensity increased due to agriculture expansion. We investigated the effect of cattle grazing on vegetation and soil salinity on the most extended Spartina densiflora community. This community develops along an elevation gradient where the frequency and duration of tidal flooding and soil salinity increased as elevation decreased. Vegetation and soil data were collected from a national park excluded to cattle grazing for 30 years and from an adjacent commercial livestock farm continuously grazed by cattle. As elevation level decreased, plant cover, richness and diversity of functional groups and species decreased. As we expected, grazing altered soil salinity and vegetation composition in different extent along the elevation gradient. Grazing changed vegetation structure more intensively in the high elevation level because it reduced the competitive exclusion exerted by S. densiflora, allowing the increase in floristic richness. Grazing increased soil salinity and the contribution of salt-tolerant species only in the medium but not in the low elevation level probably because the higher frequency and duration of tidal flooding counterbalanced the increase in evaporation promoted by biomass removal in the low respect to the medium elevation level. While grazing may cause positive impacts for plant conservation in the high elevation level, it may cause negative consequence for livestock production because of the reduction in forage quality along the entire elevation gradient.

Spring cattle grazing and mule deer nutrition in a bluebunch wheatgrass community

Although domestic cattle and mule deer (Odocoileus hemionus) share bluebunch wheatgrass (Pseudoroegneria spicata) communities throughout western United States and Canada, no study has yet evaluated the effects of cattle grazing on the nutrient intake of mule deer and the nutritional carrying capacity in these semi-arid rangelands. We expected that spring cattle grazing would decrease plant biomass available to deer but increase the nutritional quality of forage by arresting the phenology of grasses, reducing the proportion of standing dead biomass of grasses and promoting forbs. Using 0.4-ha exclosures, we created 3 replicates of paired grazed and non-grazed treatments within 3 pastures ranging from 64 to 509 ha in bluebunch wheatgrass communities on dry-stony ecological sites in southeastern Washington, USA. After cattle had grazed 1 of each pair of 0.4-ha plots to 40% utilization from 10 April to 29 May 2009, we sampled the biomass and measured the digestible energy (DE; kJ/g) and digestible protein (g/100 g feed) of plants that spring and fall. Using hand-raised, tractable mule deer, bite count methods, and behavioral observations, we measured daily DE and digestible protein intake within each plot. When compared to non-grazed plots, grazed plots had half the total and 3 times less live plant biomass in spring, and 25% less biomass in fall, whereas DE content of bluebunch wheatgrass and mule deer diets did not differ between grazing treatments. However, daily DE intake of deer was 39% less in spring and 13% less in fall in grazed than non-grazed plots. Nutritional carrying capacity (deer days/ha) did not vary between grazing treatments except for 1 pasture in fall, indicating that spring grazing by cattle in bluebunch wheatgrass communities did not improve the nutritional quality of deer diets enough to offset the overall loss of live forage biomass. © 2013 The Wildlife Society.

Effect of Cattle Grazing on Dynamics of Tree Seedlings Recruited into Semi-natural Grassland in Kitakami-sanchi Hills and Mountains, Northern Japan

Effect of Cattle Grazing on Dynamics of Tree Seedlings Recruited into Semi-natural Grassland in Kitakami-sanchi Hills and Mountains, Northern Japan

Effects of Cattle Grazing and Fire on the Abundance, Habitat Selection, and Nesting Success of the Bay-capped Wren-Spinetail (Spartonoica maluroides) in Coastal Saltmarshes of the Pampas Region

The Bay-capped Wren-Spinetail (Spartonoica maluroides, Furnariidae) is the most specialized and threatened bird inhabiting Spartina-dominated saltmarshes in southeastern South America. These marshes are being modified at an increasing rate, primarily by cattle grazing and fire, which make this spinetail highly vulnerable. To assess how land use affects the Bay-capped Wren-Spinetail, we estimated its density under different intensities of fire and cattle grazing, studied selection of nesting habitat and nest success, and experimented with nest predation to determine predation rates and types of predators. We found similar population densities, nest microhabitats, and rates of nest predation in marshes with a low intensity of or no grazing. In contrast, the species was absent from marshes with a high intensity of grazing and fire. Nest height was the best predictor of daily survival rates. Nest-predation experiments demonstrated that nest height affects predation intensity and predator type. Our results suggest that low-intensity grazing and burning during winter are compatible with the presence and reproduction of the Bay-capped Wren-Spinetail. Thus low-intensity cattle grazing is a viable alternative for the sustainable use of saltmarshes in southeastern South America.

Does Cattle Grazing Affect Ant Abundance and Diversity in Temperate Grasslands?

Half of the world's land base is grazed by domesticated livestock. Because of the important functional role of ants in grasslands, it is important to understand the effect of livestock grazing on ant abundance and diversity. The objectives of this study were to examine the effect of cattle grazing and site productivity on the abundance, species richness, and species diversity of ants in Lac du Bois Grasslands Provincial Park, British Columbia, Canada. We hypothesized that the measured ant variables would be lowest in grazed areas and at low site productivity. Pitfall trapping was conducted at four sites: two at each low and high site productivity levels. At each site an ungrazed (fenced exclosure) and grazed transect was sampled during May, July, and August of 2008. Captured ants were preserved in ethanol and identified. Eight genuses of ants were collected: Tapinoma, Camponotus, Formica, Lasius, Aphaenogaster, Myrmica, Solinopsis, and Temnotharox. The mean number of ants per pitfall was higher at high site productivity sites that were grazed (15.10 ± SE) compared to high productivity sites ungrazed (3.28 ± SE); grazing at low productivity reduced numbers of ants from 5.07 (± 0.70 SE) to 2.20 (± 0.39 SE) (F = 21.806; P [ 0.001). Tapinoma sessile and A. occidentalis had the greatest numbers in the pitfall traps. Species richness (F = 23.330, P [ 0.001) and diversity (F = 11.764, P = 0.001) followed a similar trend. Because productivity and cattle grazing affect ant diversity and abundance, and ants impact ecosystem functioning, these factors should be considered in management of grasslands. La mitad de las tierras del mundo son pastoreadas por animales domésticos. Debido a la importancia práctica de las hormigas dentro de los pastizales es importante comprender el efecto del ganado en pastoreo en la diversidad y abundancia de las hormigas. Los objetivos de este estudio fueron examinar el efecto del pastoreo y la productividad del sitio en la abundancia, la riqueza, y la diversidad de especies de hormigas en los pastizales de Lac du Bois en el parque Provincial, de la Columbia Británica, en Canadá. Nuestra hipótesis fue que las variables medidas en las hormigas serían menores en áreas pastoreadas y en sitios de menor productividad. Se utilizaron trampas en cuatro sitios: dos por cada sitio de alta y baja productividad. En cada sitio, transectos en áreas sin pastoreo (excluidas) y con pastoreo fueron muestrados durante mayo, Julio y Agosto del 2008. Las hormigas capturadas fueron conservadas en etanol e identificadas. Se recolectaron 8 géneros de hormigas: Tapinoma, Camponotus, Formica, Lasius, Aphaenogaster, Myrmica, Solinopsis, and Temnotharox. El número medio de hormigas por trampa fue mayor en de alta productividad y que fueron pastoreados (15.10 ± SE) comparados a los sitios de alta productividad sin pastoreo (3.28 ± SE); mientras que en los sitios de baja productividad se redujo el número de hormigas de 5.07 (± 0.70 SE) a 2.20 (± 0.39 SE) (F = 21.806; P [ 0.001). Las hormigas Tapinoma sessile y A. occidentalis tuvieron los mayores números en las trampas. La riqueza de las especies (F = 23.330, P [0.001) y la diversidad (F = 11.764, P = 0.001) siguió una tendencia similar. Debido a que la productividad y el pastoreo del ganando afectan la diversidad, la abundancia, y el impacto de las hormigas en el funcionamiento del ecosistema, estos factores deben considerarse en el manejo de los pastizales.

Response of plant community abundance and diversity during 10 years of cattle exclusion within silvopasture systems

The effects of cattle ( Bos taurus L.) grazing on upland plant communities in forested rangelands are poorly understood. Cattle interactions with plant communities were studied in intensively managed (precommercially thinned (PCT) and repeatedly fertilized) silvopasture systems in young lodgepole pine ( Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) forests. We investigated the response of plant community abundance and diversity to cattle grazing and how these responses were affected by PCT and repeated fertilization. The study was conducted inside and outside cattle exclosures over 10 years in two regional replicates in south-central British Columbia, Canada. PCT and repeated fertilization increased both the amount and quality of forage. Effects of cattle grazing on plant community abundance and diversity were variable and significantly influenced by the nutrient status of the site. In fertilized stands, cattle grazing increased species richness and diversity, particularly for the herb layer, although these treatment effects often took several years to be expressed. In unfertilized stands, cattle grazing did not significantly reduce herb or shrub volumes; however, species richness and, to a lesser extent, diversity of the shrub layer declined. In a landscape context, management strategies for silvopasture should promote heterogeneity for conservation of plant diversity through a variety of grazing pressures, as well as forest enhancement treatments such as PCT and repeated fertilization.

Can re-establishment of cattle grazing restore bryophyte diversity in abandoned mesic semi-natural grasslands?

Changes of agricultural practices have led to decline of semi-natural habitats sustained by traditional animal husbandry in many European regions. The abandonment of semi-natural pastures leads to increase of vascular plant biomass and subsequent decline of weak competitors such as bryophytes. Re-establishing traditional animal husbandry may potentially restore biodiversity but the success of such measures remains insufficiently known. In this study, we asked if re-establishing cattle grazing on previously abandoned grasslands will restore their bryophyte communities. The effect of cattle grazing on bryophyte communities of mesic semi-natural grasslands was studied in south-western Finland in a comparison of (i) continuously grazed pastures, (ii) previously abandoned pastures where grazing was re-established during 1990s, and (iii) abandoned pastures, where grazing had ceased during late 1960s to early 1980s. The average cover, species richness, species density and species diversity of bryophytes were significantly higher in the continuously grazed than in the abandoned grasslands. Ordination analyses revealed clear differences also in community structure between the management classes. Re-established grasslands were ecologically heterogeneous and situated in between the continuously grazed and abandoned grasslands in all characteristics, indicating variable effect of the restoration measure. Seventeen bryophyte species were recognized as significant indicators of the three grassland classes, four of which could be used as indicators of valuable grassland habitats. Although there was variation in the consequences of re-introduction of grazing, the results give evidence of positive effect of grazing on regaining bryophyte diversity of abandoned grasslands.

Assessment of Cattle Grazing Effects on E. coli Runoff

Runoff of Escherichia coli and other fecal indicator bacteria from grazing lands has been identified as a significant source of bacterial contamination. Development of best management practices to address these bacterial issues is critical to the success of watershed restoration efforts where grazing is a substantial contributor. In the present study, grazing management was evaluated to assess its effectiveness as a best management practice. Specifically, runoff from rotationally grazed and ungrazed approximately 1 ha pastures was monitored for more than two years using automated samplers. E. coli levels in runoff were enumerated by membrane filtration using modified membrane-thermotolerant Escherichia coli agar (modified mTEC). The study found that background E. coli concentrations (i.e., those from wildlife and soilborne naturalized strains) were relatively consistent among sites. Median background E. coli concentrations ranged from 3,500 to 5,500 colony forming units per 100 mL, which are not inconsequential levels related to water quality assessment and implementation efforts. Findings also indicated that rotational stocking, if timed appropriately, reduced E.coli concentrations in runoff. The impact of grazing timing in relation to runoff events was a more significant factor than stocking rate on the rotationally stocked pastures. When runoff occurred more than two weeks following grazing, E.coli levels were reduced by more than 88% compared to runoff during or soon after grazing. As a result, it is recommended that creek pastures and other hydrologically connected pastures be grazed during periods when runoff is less likely and that upland pastures be grazed during rainy seasons when runoff is more likely to occur.

Effects of grazing and invasive grasses on desert vertebrates in California

AbstractMuch of California's San Joaquin Valley is a desert and, like portions of other North American deserts, is experiencing an ecological shift from being dominated by ephemeral native forbs, with widely spaced shrubs, to fire‐prone non‐native annual grasses. Small terrestrial vertebrates, many of which are adapted to open desert habitats, are declining. One hypothesis is that the invasive plants contribute to the decline by altering vegetative structure. Although cattle may have originally been a factor in the establishment of these non‐native plants, their grazing may benefit the terrestrial vertebrates by maintaining an open structure, especially during average or wet winters when the exotic grasses grow especially dense. We experimentally tested the effect of cattle grazing on invasive plants and a community of small vertebrates at a site in the southwestern San Joaquin Desert. We established and monitored 4 treatment (grazed) and 4 control (ungrazed) plots from 1997 to 2006, and assessed the abundances of blunt‐nosed leopard lizards (Gambelia sila), giant kangaroo rats (Dipodomys ingens), short‐nosed kangaroo rats (Dipodomys nitratoides nitratoides), and San Joaquin antelope squirrels (Ammospermophilus nelsoni), all of which are listed as threatened or endangered by state or federal agencies. We also recorded abundances of the non‐protected western whiptail lizards (Aspidoscelis tigris), side‐blotched lizards (Uta stansburiana), San Joaquin pocket mice (Perognathus inornatus inornatus), and Heermann's kangaroo rats (Dipdomys heermanni). Based on repeated measures analysis of variance (ANOVA) and a 0.05 alpha level, only Heermann's kangaroo rats showed a treatment effect; they were more abundant on the control plots. However, this effect could be accounted for by the natural re‐establishment of saltbush (Atriplexspp.) on part of the study site. Saltbush return also favored western whiptail lizards and San Joaquin antelope squirrels. A regression analysis indicated that populations of blunt‐nosed leopard lizard and giant kangaroo rat increased significantly faster in grazed plots than the ungrazed controls, and abundances of 6 of 8 species were negatively correlated with increased residual dry matter. With relaxed alpha values to decrease Type II error, populations of blunt‐nosed leopard lizards (500% greater), San Joaquin antelope squirrels (85% greater), and short‐nosed kangaroo rats (73% greater) increased significantly on grazed plots over the course of the study compared to ungrazed plots. We did not find grazing to negatively affect abundance of any species we studied. When herbaceous cover is low during years of below average rainfall in deserts and other arid areas, grazing may not be necessary to maintain populations of small vertebrates. However, if cattle grazing is closely monitored in space and time to minimize adverse effects on the habitat, it could be an effective tool to control dense stands of non‐native grasses and benefit native wildlife. © 2011 The Wildlife Society.

Effects of Cattle Grazing on Birds in Interior Douglas-Fir (Pseudotsuga Menziesii) Forests of British Columbia

Livestock grazing is a dominant land use across North America and although the effects of grazing on birds have been studied in grassland, shrubland, and riparian habitats, studies of the effects in forests are rare. We investigated the effects of cattle grazing in forests on vegetation, the relationships between vegetation characteristics and the abundance of foraging and nesting guilds of birds, and the overall effects of grazing on the bird community in the Interior Douglas-fir (Pseudotsuga menziesii) biogeoclimatic zone of British Columbia. Cattle grazing was associated with reduction in ground vegetation height and grass cover, and increases in the number of shrubs and saplings. Bark insectivores, foliage insectivores, cavity nesters, and shrub/tree nesters all responded positively to sapling density. However, this translated into few overall effects of cattle grazing on birds, with only bark insectivores exhibiting greater abundance on grazed areas. Grazed areas also had fewer aerial insectivores but the mechanism driving this remains unclear. Current forest grazing practices at our study sites appear to have few negative effects on bird abundance and diversity, with the possible exception of aerial insectivores. Study of additional sites is required to assess if forest grazing exerts similar effects throughout the Interior Douglas-fir forest. Furthermore, study of the effects of forest grazing on productivity and survival of birds is needed.

Vegetation changes associated with cattle (Bos taurus) and wombat (Vombatus ursinus) activity in a riparian forest

AbstractQuestionIs the composition of groundstorey vegetation influenced by wombat burrowing and mound construction as well as streambank tracks by domestic cattle at high and low levels of usage?LocationSixteen streambank study sites in an agricultural area in Kangaroo Valley, southeastern New South Wales, Australia.MethodsWe examined the effects of cattle and wombats on vegetation by measuring plant and litter cover on three markedly different microsites; wombat mounds, the network of tracks used by both cattle and wombats to access pastures away from the riparian area, and control sites that were neither tracks nor mounds, and which were located 1–2 m away from mounds or tracks.ResultsWe recorded significantly fewer vascular plant species on the mounds and tracks than on the control microsites, but there were significantly more species at sites of high cattle usage than low cattle usage. Plant cover on the control microsites was more than twice that on the mounds and tracks. The exotic plants, panic veldt grass (Ehrharta erecta) and kikuyu (Pennisetum clandestinum) were typical indicators of high cattle use sites, while wandering jew (Tradescantia fluminensis) and to a lesser extent the unpalatable, low‐sprawling shrub mistflower (Ageratina riparia) were indicators of low cattle use sites.ConclusionsOur study demonstrates that there are few differences in plant community composition between microsites constructed by cattle and those of wombats. Both microsites supported a community that was a subset of the species pool in the surrounding vegetation. Cattle grazing since 1851 in Kangaroo Valley has probably reduced disturbance‐sensitive plant species, resulting in an effect that is more apparent at the landscape scale. Further study should focus on the landscape‐scale effects of cattle grazing to determine whether cattle or wombats are the major causes of ecosystem degradation in Australian riparian environments.

Effects of cattle grazing on herbage quality in a herbaceous Mediterranean rangeland

AbstractThe main objective of this study was to determine to what extent grazing pressure and timing modulate the seasonal progression of herbage quality in hilly Mediterranean grassland systems. The study was conducted during six consecutive years between 2003 and 2008 at the Karei Deshe experimental farm, in eastern Galilee, Israel, dominated by rich hemicryptophytic grassland. Treatments included two different grazing intensities, heavy and moderate, with 1·1 and 0·55 cows ha−1, respectively, and management that included a continuous and a seasonal stocking system that was divided at both intensities into early and late grazing. Herbage samples were analysed for digestibility, crude protein, neutral detergent fibre and acid detergent fibre contents. Significant differences in herbage quality were found between seasons and years. Herbage quality was significantly higher in paddocks grazed continuously or early in the season. Herbage quality increased with increasing grazing intensity as younger herbage and continued re‐growth were maintained during the green season. The greater difference between herbage qualities was found at the peak of the growing season. The significant differences found in herbage quality emphasize the importance of the decision‐making process aimed at improving cattle grazing management in Mediterranean rangelands and its consequences for the sustainability of the system.

Plant diversity partitioning in grazed Mediterranean grassland at multiple spatial and temporal scales

Summary1. Grazing by large ungulates may affect plant species richness and diversity at multiple spatial and/or temporal scales, because grazing affects small‐scale resource heterogeneity and plant interactions at the local scale, while effects at the landscape scale are related to grazing intensity and timing.2. We used diversity partitioning to analyse long‐ and short‐term effects of cattle grazing on plant species richness and diversity in an experimental spatial hierarchy in Mediterranean annual grassland. Short‐term changes during secondary succession in grazed plots (2003–2005) at two grazing intensities (heavy and moderate) were analysed and compared with long‐term protected vegetation. We applied Hill’s q‐diversity metrics at q = 0 (species richness) and q = 2 (reciprocal Simpson diversity) to examine the partitioning of species richness and diversity between their alpha (α) and beta (β) components in the different treatments at four spatial scales: quadrats, within exclosures, within plots, within treatments.3. At q = 0, α‐diversity was always significantly lower, and β‐diversity significantly higher, than predicted by the randomised null model. Diversity partitioning at q = 2 showed a similar trend at the quadrat scale. At the exclosure scale, partitioning exhibited a similar trend during the first 2 years of secondary succession but did not deviate from the null model in the third year, as observed in protected vegetation in all years.4. At q = 0, diversity decreased across all treatments in the short term. At q = 2, diversity was initially higher in grazed plots than in protected vegetation; α and β components both decreased during secondary succession, to the levels observed in the protected vegetation.5. Synthesis and applications.. Lower dominance in grazed vegetation indicates that grazing affects competitive exclusion at the local, small scale and accentuates natural heterogeneity (e.g. patchiness of soil resources, presence of rocks in the landscape) at a larger scale. The results of this study emphasise the importance of grazing as a management tool for maintaining plant diversity at multiple scales. This is a major concern worldwide, as the area covered by natural ecosystems continues to dwindle, necessitating management of grasslands for multiple functions such as animal production, resource protection and wildlife enhancement.

Tillage and Cattle Grazing Effects on Soil Properties and Grain Yields in a Dryland Wheat–Sorghum–Fallow Rotation

Cattle (Bos taurus) grazing intensifies production of the dryland wheat (Triticum aestivum L.)–sorghum [Sorghum bicolor (L.) Moench]–fallow (WSF) rotation in the U.S. Southern High Plains. Stubble‐mulch (SM) tillage controls weeds and counteracts soil compaction. No‐till (NT) increases soil water at planting and dryland crop yields, but added grazing effects are unknown. Our objectives were to quantify dryland winter wheat and sorghum yield responses to grazing and tillage practices. At the USDA‐ARS Conservation and Production Research Laboratory, Bushland, TX, we established all WSF rotation phases in triplicate ungrazed and grazed paddocks beginning 1999 on a Pullman clay loam (fine, mixed, superactive, thermic Torrertic Paleustoll) using SM tillage. During spring 2004, NT or SM tillage were superimposed within grazing main plots. Cattle gain, soil water after fallow, and crop yield were compared during 2005 to 2009 using a split‐plot randomized complete block design. Cattle, stocked at 1.8 Mg ha−1, grazed sorghum stover and growing wheat an average of 29 d for a mean gain of 147 kg ha−1 Soil water at planting was unaffected by grazing, but increased from 14 to 28 mm with NT. Although grazing seldom reduced yield of wheat or sorghum, NT in ungrazed plots increased crop yields sufficiently (0.96–2.6 Mg ha−1) in 2008 and 2009 to offset any value added by grazing. We conclude that cumulative grazing effects in NT plots reduced soil water storage and depressed yield. We recommend post‐wheat‐harvest SM tillage to disrupt soil compaction and restore grazed soil productivity.