Artículos de revistas: "Pasture ecology"

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Reed, Kinsey y Ember M. Morrissey. "Bridging Ecology and Agronomy to Foster Diverse Pastures and Healthy Soils". Agronomy 12, n.º 8 (12 de agosto de 2022): 1893. http://dx.doi.org/10.3390/agronomy12081893.

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Renovating pastures to increase forage species diversity is a burgeoning practice among producers. Over a century of grassland and small-plot research suggests that increasing plant diversity can lead to improved pasture productivity, resilience, and soil health. However, it remains hard to decipher how these benefits translate to grazed production systems given the limited experimentation in realistic grazing systems. There is a disconnect between ecological and agronomic research regarding what qualifies as a “diverse” grassland or pasture. This review aims to examine the current state of research regarding plant diversity and its potential benefits for soil health in pasture systems, and outlines how we can improve our understanding and implementation of this practice in production systems.

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SARMIENTO, FAUSTO O. "Arrested succession in pastures hinders regeneration of Tropandean forests and shreds mountain landscapes". Environmental Conservation 24, n.º 1 (marzo de 1997): 14–23. http://dx.doi.org/10.1017/s0376892997000052.

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Arrested succession is conspicuous in the abandoned pastures of the Andean piedmont that have encroached upon the tropical montane forests toward higher limits and steeper slopes. Habitat 'shredding' is analysed to depict the current spatial configuration of tropical Andean landscapes, based on fragmentation patterns prompted by seed dispersal ecology and pasture encroachment.Seed dispersal was studied to address the hypo-thesis that seed input constrains the recruitment of montane forest seedlings, thus impeding pasture conversion to forest. It turns out that a better competitor, the tussock grass Setaria sphacelata, is limiting dispersal success due to its bioarchitecture and planting patterns. Because of the variegation of fragments, the area is in danger of landscape homogeneity within a matrix of degraded pasture. Currently, protection of fragmented remnants and restoration of original landscape structure and function are urgent needs for land-use planning toward sustainable development in the region.Restoration ecology is plausible as a means of conservation for degraded Tropandean forests, since human impacts have shredded landscapes entirely. Dispersal ecology may be used to facilitate pasture conversion to forest in equatorial landscapes, but the proactive approach of pasture removal or planting strategy should differ from that for lowland Amazonia, where abandoned pastures are different from those of montane environs. However, the region may be proactively managed only if political decisions include conservation as a goal of development.

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Robinson, GG y PM Dowling. "The effect of proportion of sown grasses on pasture and animal production from fertilised pastures on the Northern Tablelands of New South Wales." Rangeland Journal 7, n.º 2 (1985): 88. http://dx.doi.org/10.1071/rj9850088.

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Pasture and animal production from fertilised pastures with varying proportions of sown grass (0-60%) were recorded and compared. The presence of sown grass increased pasture production when compared to natural pasture, but no difference was detected in liveweight or wool production between the var- ious pastures. It is doubtful whether sowing of introduced grasses for wool production can be justified at the levels of grazing intensity usually adopted on the Northern Tablelands.

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Silcock, R. G., T. J. Hall, P. G. Filet, A. M. Kelly, D. Osten y T. W. G. Graham. "Floristic composition and pasture condition of Aristida/Bothriochloa pastures in central Queensland. II. Soil and pasture condition interactions". Rangeland Journal 37, n.º 2 (2015): 217. http://dx.doi.org/10.1071/rj14107.

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Sustainable management of native pastures requires an understanding of what the bounds of pasture composition, cover and soil surface condition are for healthy pastoral landscapes to persist. A survey of 107 Aristida/Bothriochloa pasture sites in inland central Queensland was conducted. The sites were chosen for their current diversity of tree cover, apparent pasture condition and soil type to assist in setting more objective bounds on condition ‘states’ in such pastures. Assessors’ estimates of pasture condition were strongly correlated with herbage mass (r = 0.57) and projected ground cover (r = 0. 58), and moderately correlated with pasture crown cover (r = 0.35) and tree basal area (r = 0.32). Pasture condition was not correlated with pasture plant density or the frequency of simple guilds of pasture species. The soil type of Aristida/Bothriochloa pasture communities was generally hard-setting, low in cryptogam cover but moderately covered with litter and projected ground cover (30–50%). There was no correlation between projected ground cover of pasture and estimated ground-level cover of plant crowns. Tree basal area was correlated with broad categories of soil type, probably because greater tree clearing has occurred on the more fertile, heavy-textured clay soils. Of the main perennial grasses, some showed strong soil preferences, for example Tripogon loliiformis for hard-setting soils and Dichanthium sericeum for clays. Common species, such as Chrysopogon fallax and Heteropogon contortus, had no strong soil preference. Wiregrasses (Aristida spp.) tended to be uncommon at both ends of the estimated pasture condition scale whereas H. contortus was far more common in pastures in good condition. Sedges (Cyperaceae) were common on all soil types and for all pasture condition ratings. Plants identified as increaser species were Tragus australianus, daisies (Asteraceae) and potentially toxic herbaceous legumes such as Indigofera spp. and Crotalaria spp. Pasture condition could not be reliably predicted based on the abundance of a single species or taxon but there may be scope for using integrated data for four to five ecologically contrasting plants such as Themeda triandra with daisies, T. loliiformis and flannel weeds (Malvaceae).

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Lodge, G. M. "Studies of soil seedbanks in native and sown pastures in northern New South Wales". Rangeland Journal 23, n.º 2 (2001): 204. http://dx.doi.org/10.1071/rj01007.

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Total and germinable soil seedbanks (litter and soil) were studied for a native pasture and three sown pastures (dominated by Phalaris aquatica L. cv. Sirosa) in northern New South Wales from 1993 to 1996. Soil core samples were taken from continuously grazed plots for both pasture types and two oversown treatments in the native pasture and from a spring-autumn rest treatment at the sown pasture sites. At each site above ground herbage mass was also estimated regularly as part of the Temperate Pasture Sustainability Key Program. For all sites and treatments, the proportion of germinable seeds as a percentage of the total (dormant and germinable) seedbank ranged from 1–26% for the native pasture and 1–39% for the sown pastures. Germinable seed numbers ranged from 280 to 26,110 seeds per m2, while total seedbank numbers were from 6700 to 178,360 seeds per m2. Native pasture herbage mass was dominated by native perennial grasses, but seeds of these species were less than 20% of the total seed bank in all treatments in 1994 and 1995. At the sown pasture sites, most of the germinable (51–92%) and total (65–97%) seedbanks were either barnyard grass (Echinochloa crus-galli (L.) Beauv, annual ryegrass (Lolium rigidum Gaudin), subterranean clover (Trifolium subterraneum L.) or wireweed (Polygonum aviculare L.). Since seeds of annuals and other forbs generally dominated both the total and germinable seedbanks of these perennial grass-based pastures, these species were likely to increase over time. Seeds of the sown perennial grass Phalaris aquatica L, cv. Sirosa were less than 1% of the total seedbanks in pastures sown in 1990 and less than 3% of those sown in 1979. With above average summer rainfall at the native pasture site in 1996 and prolific growth of redgrass, seeds of this species were 38–63% of the total and 11–29% of the germinable seedbank in May 1996. Except at this site and time, the species composition of the total and germinable seedbanks did not generally reflect the dominance of the above ground herbage mass of these pastures by perennial grasses.

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Vere, D. T., R. E. Jones y M. H. Campbell. "The economics of temperate pasture systems on the central and southern Tablelands of New South Wales". Rangeland Journal 23, n.º 2 (2001): 159. http://dx.doi.org/10.1071/rj01003.

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Pastures are the basis of most forms of agricultural production on the New South Wales central and southern tablelands. Pastures occupy the bulk of the region's landmass and pasture-based livestock production annually contributes more than three-quarters of the regional gross value of rural production. Throughout the region, there is substantial variation in pasture composition, ranging from high quality introduced perennial grasses and legumes to pastures comprising mainly low quality native species. This paper examines the economics of the main categories of temperate pastures over a range of soil fertility-rainfall environments on the south-eastern tablelands areas of New South Wales. Using a linear programming model and discounted development budgets, the results demonstrate the strong influence of the environment on the economics of the individual pasture systems. The highest economic returns in both the short and longer-terms were to the introduced perennial grass pastures in most of the environments. Pastures based on introduced legumes and the high quality native species also generated sound economic returns, although there are recognised problems with the persistence of the legume pastures. Over time, the returns to the better quality native pastures compare favourably with the introduced legumes and are better suited to acidic soils than the perennial grasses. Low quality native species produced relatively poor economic returns in all environments and unfortunately, are the main pasture type in the region's less favourable environments.

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Robertson, G. "Effect of drought and high summer rainfall on biomass and comsumption of grazed pastures in western New South Wales." Rangeland Journal 9, n.º 2 (1987): 79. http://dx.doi.org/10.1071/rj9870079.

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The biomass and composition of grazed pastures near Menindee, in westem New South wales, were estimated over a range of seasonal condilions between 1980 and 1985. Differences in biomass and composition of pastures grazed separately by kangaroos and by a mixture of sheep and kangaroos were minor. Pasture biomass ranged from 7 kgha during a drought to 1,100 kgha following high summer rainfall. Overall, biomass average 374 kgha with a slandard deviation among years of 302 kgha. Pasture biomass fluctuated markedly among calendar seasons and years in response to erratic rainfall and grazing. I-Iigh summer rainfall triggered a switch in pasture dominatnace from annuals to shoa-lived perennials.

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Stevens, D. R. "Managing sheep and beef farm systems - where does pasture persistence fit in?" NZGA: Research and Practice Series 15 (1 de enero de 2011): 191–98. http://dx.doi.org/10.33584/rps.15.2011.3202.

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Pasture persistence is highly rated by sheep and beef farmers as an important factor determining wholefarm performance. Managing pastures to ensure the persistence of newly sown pasture species must be considered as a part of the decision making process of the whole farm. The farmer aims to optimise the outcomes of resource use over time, rather than maximise any single resource, and therefore grazing decisions must be considered in this context. Pasture renewal is a major event-driven disruption that replaces current pasture species with competitive species, creating a grass-legume complex that has a tendency to develop towards a community of plants that tolerate the local environmental stress. Pasture persistence can be improved through managing the impacts of and interactions between environmental stressors on the pasture. Interactions between pasture management options, such as grazing and fertiliser, and the major environmental stressors of soil moisture, temperature, soil fertility, grazing and pests are discussed. Keywords: ecology, environmental stressors, farm systems, grazing management, pasture persistence.

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9

Silcock, R. G., T. J. Hall, P. G. Filet, A. M. Kelly, D. Osten, C. M. Schefe y P. T. Knights. "Floristic composition and pasture condition of Aristida/Bothriochloa pastures in central Queensland. I. Pasture floristics". Rangeland Journal 37, n.º 2 (2015): 199. http://dx.doi.org/10.1071/rj14106.

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A survey was conducted in central inland Queensland, Australia of 108 sites that were deemed to contain Aristida/Bothriochloa native pastures to quantitatively describe the pastures and attempt to delineate possible sub-types. The pastures were described in terms of their floristic composition, plant density and crown cover. There were generally ~20 (range 5–33) main pasture species at a site. A single dominant perennial grass was rare with three to six prominent species the norm. Chrysopogon fallax (golden-beard grass) was the perennial grass most consistently found in all pastures whereas Aristida calycina (dark wiregrass), Enneapogon spp. (bottlewasher grasses), Brunoniella australis (blue trumpet) and Panicum effusum (hairy panic) were all regularly present. The pastures did not readily separate into broad floristic sub-groups, but three groups that landholders could recognise from a combination of the dominant tree and soil type were identified. The three groups were Eucalyptus crebra (narrow-leaved ironbark), E. melanophloia (silver-leaved ironbark) and E. populnea (poplar box). The pastures of the three main sub-groups were then characterised by the prominent presence, singly or in combination, of Bothriochloa ewartiana (desert bluegrass), Eremochloa bimaculata (poverty grass), Bothriochloa decipiens (pitted bluegrass) or Heteropogon contortus (black speargrass). The poplar box group had the greatest diversity of prominent grasses whereas the narrow-leaved ironbark group had the least. Non-native Cenchrus ciliaris (buffel grass) and Melinis repens (red Natal grass) were generally present at low densities. Describing pastures in terms of frequency of a few species or species groups sometimes failed to capture the true nature of the pasture but plant abundance for most species, as density, herbage mass of dry matter or plant crown cover, was correlated with its recorded frequency. A quantitative description of an average pasture in fair condition is provided but it was not possible to explain why some species often occur together or fail to co-exist in Aristida/Bothriochloa pastures, for example C. ciliaris and E. bimaculata rarely co-exist whereas Tragus australianus (small burrgrass) and Enneapogon spp. are frequently recorded together. Most crown cover was provided by perennial grasses but many of these are Aristida spp. (wiregrasses) and not regarded as useful forage for livestock. No new or improved categorisation of the great variation evident in the Aristida/Bothriochloa native pasture type can be given despite the much improved detail provided of the floristic composition by this survey.

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Graetz, RD. "A Comparative Study of Sheep Grazing a Semi-Arid Saltbush Pasture in Two Condition Classes." Rangeland Journal 8, n.º 1 (1986): 46. http://dx.doi.org/10.1071/rj9860046.

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Measurements were made of the wool growth, body weight gain and diet of sheep grazing a saltbush pasture near Broken Hill, N.S.W. The experiment utilized a fenceline contrast in saltbush (Atriplex vesrcarra) density that was visible on Landsat imagery. It ran for five years (1976-1981) with a design of two pasture types by two stocking rates. Fleece weights varied from 3.9-6.0 kg/head and wool production from 0.6-2.9 kg/ha. Neither wool production per head nor bodyweight were substantially affected by stocking rate or pasture type. The composition and quality of the diets selected by sheep on both pastures were identical and of high nutritional value indicating their capability to accommodate differences in pasture composition. Pasture quality was not limiting between stocking rates or determined by the abundance of saltbush. Changes in pasture composition resulting from grazing and exclosure were small and of no significance.

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Kaur, Kamaljit, David J. Midmore, Rajesh K. Jalota y Nanjappa Ashwath. "Pasture composition in cleared and uncleared woodlands". Australian Journal of Botany 54, n.º 5 (2006): 459. http://dx.doi.org/10.1071/bt05174.

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Land clearing in Queensland is often practised to enhance pasture production, and hence, increase financial returns from beef production. The benefits of clearing have been quantified in terms of short-term gains in pasture yield but have not adequately accounted for possible medium- or longer-term impediments that may be attributed to clearing. Therefore, impacts of clearing and the subsequent sowing of exotic grasses such as Cenchrus ciliaris L. on pasture composition and production were studied. To achieve this, paired sites were selected representing cleared and uncleared pastures across three different times since clearing (i.e. 5, 11–13 and 33 years since clearing) for the three dominant tree communities of central Queensland (i.e. Eucalyptus populnea F.Muell. (poplar box), E. melanophloia F.Muell. (silver-leaved ironbark) and Acacia harpophylla F.Muell. ex. Benth. (brigalow)). The results demonstrated that species diversity declined with clearing and sowing of exotic pastures. Species diversity and pasture production were negatively related. Although pasture yield was 2–3 times greater 13 years after clearing of E. populnea and A. harpohylla, the gains in pasture yield were not consistent over time, yields being only 1.5 times greater after 33 years of clearing. In E. melanophloia, an increase in the yield of only 1.5–1.8 times occurred 5 years after clearing compared with uncleared pastures, whereas 33 years after clearing, yield was 3/4 of that in uncleared pastures. The initial gains in pasture yield were accompanied by a loss of plant diversity that may affect ecosystem functions such as nutrient cycling or soil mineralisation, and the longer-term production gains.

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Kaur, K., R. K. Jalota, D. J. Midmore y J. Rolfe. "Pasture production in cleared and uncleared grazing systems of central Queensland, Australia". Rangeland Journal 27, n.º 2 (2005): 143. http://dx.doi.org/10.1071/rj05012.

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Clearing land of trees and introducing exotic pastures to enhance pasture and cattle production and hence enterprise financial performance are widely practised in Queensland. The results from many previous studies on tree clearing have emphasised the gains in pasture production, but over periods of less than 10–15 years after clearing. The present study questioned the sustainability of pasture production in cleared systems over a longer time-frame (>10 years of clearing). For this, three different age groups of clearing i.e. 5 year, 11–13 year and 33 year were selected in each of 3 major types of tree communities i.e. Eucalyptus populnea, E. melanophloia and Acacia harpophylla in central Queensland. Paired comparisons of cleared and uncleared (intact) pasture systems were selected for each age group of clearing. The results suggest that the initial gains in pasture production upon clearing were compatible with published studies. However, for longer periods of time since clearing, the gains in pasture production were not sustained and were accompanied by risks of land degradation and loss of pasture plant diversity. For E. populnea and A. harpophylla, the maximum benefits from clearing were achieved at 13–15 years whereas for E. melanophloia, any benefits existed only over a short period of 5–6 years. The study emphasises that each tree community exhibits a specific response with regard to the duration of increased pasture production following clearing. To estimate the total benefits from tree clearing in pasture development, it is important to consider both monetary benefits and non-monetary losses from clearing for different types of tree communities.

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Wick, B., E. Veldkamp, W. Z. de Mello, M. Keller y P. Crill. "Nitrous oxide fluxes and nitrogen cycling along a pasture chronosequence in Central Amazonia, Brazil". Biogeosciences 2, n.º 2 (2 de agosto de 2005): 175–87. http://dx.doi.org/10.5194/bg-2-175-2005.

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Abstract. We studied nitrous oxide (N2O) fluxes and soil nitrogen (N) cycling following forest conversion to pasture in the central Amazon near Santarém, Pará, Brazil. Two undisturbed forest sites and 27 pasture sites of 0.5 to 60 years were sampled once each during wet and dry seasons. In addition to soil-atmosphere fluxes of N2O we measured 27 soil chemical, soil microbiological and soil physical variables. Soil N2O fluxes were higher in the wet season than in the dry season. Fluxes of N2O from forest soils always exceeded fluxes from pasture soils and showed no consistent trend with pasture age. At our forest sites, nitrate was the dominant form of inorganic N both during wet and dry season. At our pasture sites nitrate generally dominated the inorganic N pools during the wet season and ammonium dominated during the dry season. Net mineralization and nitrification rates displayed large variations. During the dry season net immobilization of N was observed in some pastures. Compared to forest sites, young pasture sites (≤2 years) had low microbial biomass N and protease activities. Protease activity and microbial biomass N peaked in pastures of intermediate age (4 to 8 years) followed by consistently lower values in older pasture (10 to 60 years). The C/N ratio of litter was low at the forest sites (~25) and rapidly increased with pasture age reaching values of 60-70 at pastures of 15 years and older. Nitrous oxide emissions at our sites were controlled by C and N availability and soil aeration. Fluxes of N2O were negatively correlated to leaf litter C/N ratio, NH4+-N and the ratio of NO3--N to the sum of NO3--N + NH4+-N (indicators of N availability), and methane fluxes and bulk density (indicators of soil aeration status) during the wet season. During the dry season fluxes of N2O were positively correlated to microbial biomass N, β-glucosidase activity, total inorganic N stocks and NH4+-N. In our study region, pastures of all age emitted less N2O than old-growth forests, because of a progressive decline in N availability with pasture age combined with strongly anaerobic conditions in some pastures during the wet season.

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Wick, B., E. Veldkamp, W. Z. de Mello, M. Keller y P. Crill. "Nitrous oxide fluxes and nitrogen cycling along a pasture chronosequence in Central Amazonia, Brazil". Biogeosciences Discussions 2, n.º 3 (4 de mayo de 2005): 499–535. http://dx.doi.org/10.5194/bgd-2-499-2005.

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Abstract. We studied nitrous oxide (N2O) fluxes and soil nitrogen (N) cycling following forest conversion to pasture in the central Amazon near Santarém, Pará, Brazil. Two undisturbed forest sites and 27 pasture sites of 0.5 to 60 years were sampled once each during wet and dry seasons. In addition to soil-atmosphere fluxes of N2O we measured 27 soil chemical, soil microbiological and soil physical variables. Soil N2O fluxes were higher in the wet season than in the dry season. Fluxes of N2O from forest soils always exceeded fluxes from pasture soils and showed no consistent trend with pasture age. At our forest sites, nitrate was the dominant form of inorganic N both during wet and dry season. At our pasture sites nitrate generally dominated the inorganic N pools during the wet season and ammonium dominated during the dry season. Net mineralization and nitrification rates displayed large variations. During the dry season net immobilization of N was observed in some pastures. Compared to forest sites, young pasture sites (≤2 years) had low microbial biomass N and protease activities. Protease activity and microbial biomass N peaked in pastures of intermediate age (4 to 8 years) followed by consistently lower values in older pasture (10 to 60 years). The C/N ratio of litter was low at the forest sites (~25) and rapidly increased with pasture age reaching values of 60–70 at pastures of 15 years and older. Nitrous oxide emissions at our sites were controlled by C and N availability and soil aeration. Fluxes of N2O were negatively correlated to leaf litter C/N ratio, NH4+-N and the ratio of NO3--N to the sum of NO3--N + NH4+-N (indicators of N availability), and methane fluxes and bulk density (indicators of soil aeration status) during the wet season. During the dry season fluxes of N2O were positively correlated to microbial biomass N, β-glucosidase activity, total inorganic N stocks and NH4+-N. In our study region, pastures of all age emitted less N2O than old-growth forests, because of a progressive decline in N availability with pasture age combined with strongly anaerobic conditions in some pastures during the wet season.

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López-Olmedo, L. I., J. A. Meave y E. A. Pérez-García. "Floristic and structural contrasts between natural savannas and anthropogenic pastures in a tropical dry landscape". Rangeland Journal 29, n.º 2 (2007): 181. http://dx.doi.org/10.1071/rj07007.

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The magnitude of the biological differentiation between natural savannas and pastures (anthropogenic grasslands) coexisting in a single landscape, in terms of their floristic composition and community structure, was studied in the Nizanda region, Isthmus of Tehuantepec, Oaxaca State, southern Mexico. Vegetation samples of 15 m2 each were taken at 20 savanna and 11 pasture sites. Cover- and species richness-based diversity and dominance indices were calculated. Geomorphological and edaphic characteristics were also compared. Savannas generally occurred in hill summits with very shallow and stony, discontinuous and acidic soils; contrastingly, pastures were located in piedmonts and floodplains, with more neutral and less stony soils. Savanna sites differed from pasture sites in species richness and Shannon diversity. They did not differ in Simpson dominance index, but the identity of the dominant species was different in each community: Trachypogon spicatus (L.f.) Kuntze in savanna and Megathyrsus maximus (Jacq.) B.K.Simon et S.W.L.Jacobs in pasture. A low species-level similarity (Sørensen Index) was observed between them (8.2%), and genus-level similarity was only slightly higher (27.1%). The magnitude of the biological differentiation in both community floristics and structure between these two grass-dominated communities was larger than anticipated. Current management of savannas as pasture lands may potentially trigger a severe deterioration process involving both the landscape and its plant components.

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Barnes, Phoebe, Brian R. Wilson, Mark G. Trotter, David W. Lamb, Nick Reid, Terry Koen y Leopold Bayerlein. "The patterns of grazed pasture associated with scattered trees across an Australian temperate landscape: an investigation of pasture quantity and quality". Rangeland Journal 33, n.º 2 (2011): 121. http://dx.doi.org/10.1071/rj10068.

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Scattered paddock trees occur across agricultural landscapes in Australia. However, in the temperate regions of Australia their numbers are rapidly declining and they may be lost across much of the landscape in 200 years. Here we examined the spatial distribution of green (GDB), senescent (SDB) and total (TDB) dry pasture biomass, and nutrient status of the GDB fraction around scattered Eucalyptus trees on three parent materials (basalt, granite and meta-sediment) in native and sown pastures across a range of grazed temperate landscapes in northern New South Wales. We used a combination of destructive harvests and a handheld active optical canopy reflectance sensor (AOS) with an integrated GPS to examine pasture biomass around scattered trees. The harvested pasture biomass data indicated that under grazed conditions the presence of scattered trees did not introduce significant radial trends in TDB or GDB out to a distance of 3.5 canopy radii regardless of tree species or parent material. The red and near-infrared reflectance-based Normalised Difference Vegetation Index (NDVI), as measured by the AOS, did indicate a consistent azimuthal trend with larger GDB on the southern side of the tree and lower GDB on the northern side in the native pasture. However, this observation must be qualified as the regression coefficient for the relationship between NDVI and GDB was significant but weak (best r2 = 0.42), and SDB reduced its predictive capacity. We also found a higher percentage of GDB under the canopy than in the open paddock. We suggest that the combination of these results may indicate higher grazing pressure under trees than in the open paddock. Pasture nutrient concentration (P, K and S) was higher in both native and sown pastures beneath the tree canopy compared with the open paddock. This study indicates that, in this temperate environment, scattered trees do not adversely affect pasture production, and that they can improve some pasture nutrients.

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Stephenson, RGA, DA Pritchard, PM Pepper y PT Connelly. "The effect of different pasture management strategies in north-west Queensland on liveweight gain and wool growth rate of several groups of young sheep." Rangeland Journal 7, n.º 2 (1985): 75. http://dx.doi.org/10.1071/rj9850075.

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The effect of three different pasture management strategies on liveweight gain and wool growth rate of young(weaner) sheep was examined immediately after weaning on Mitchell grass-Flinders grass pastures during the dry season of north-west Queensland. The pasture management strategies were designed to mimic various industry situations, while the performance of four different progeny groups was compared and used to provide an overall assessment of pasture quality. Pasture treatments (experiment 1) consisted of three paddocks, a harvested (c. 8% of pasture harvested and baled) and spelled, a spelled, and a continuously grazed paddock. Spelled paddocks were not grazed during and after the wet season for a period of six months while the continuously grazed paddock was continuously stocked before the experiment. Experiment 2 consisted of spelled and continuously grazed paddocks. Pastures were evaluated by measuring the changes in composition and quality (experiment 1) and the responses in liveweight gain (experiments 1 and 2) and wool growth of the weaners (experiment 1). Marked improvements (c. 100%) in weaner growth rates occurred in the spelled paddocks. Greasy wool production by three groups of ewes in experiment I was about 14% greater in the harvested paddock than in the others. At the start of the trial there were no significant differences in dry matter yield but a significant difference in botanical composition occurred between paddocks. The changes in dry matter that occurred between the beginning and end of grazing were not significantly different between paddocks. Before gazing, forbs made up approximately 16%, 4% and 1% of pastures in harvested, spelled and continuously grazed paddocks respectively. The change in the percentage forbs that occurred between the beginning and end of the grazing period was significantly greater in the harvested paddock than in the other paddocks indicating preferential selection and intake by sheep. The differences in weaner live weight and wool growth between paddocks suggest that paddock management can improve weaner productivity. The study also indicates that paddock management could be successfully used to increase the percentage of forbs and quality of the pasture during the dry season. The superior wool growth of two progeny groups also suggests that improved productivity of breeding flocks in the tropics is possible if superior sheep can be identified. The results highlight the importance of preferential management of pasture for weaners so that productivity advantages can be exploited.

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Nadolny, Christopher. "Towards integrating farming and conservation: the role of native pastures". Pacific Conservation Biology 4, n.º 1 (1998): 70. http://dx.doi.org/10.1071/pc980070.

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Agriculture has almost certainly contributed to the decline of native vegetation and wildlife in rural Australia. A prevalent culture supports agricultural systems that rely on the use of exotic plants and animals and greater use of chemicals and machinery. In general, these systems do not fully utilize or take account of the indigenous biota. The full implications of implementing such farming systems on a landscape scale are seldom considered. I use the grazing industry on the Northern Tablelands of New South Wales to illustrate two contrasting approaches: (1) "pasture improvement" involving replacement of native with exotic species versus (2) retention and management of existing native and naturalized pasture species. Pasture improvement has been refined by extensive agronomic research, plant selection and field testing of techniques. Nevertheless, the approach is losing support among farmers because of high inputs required to maintain "improved" pastures, the fragility of these pastures during droughts, low commodity prices, longterm declines in soil structure and increases in soil acidity. Other side-effects include tree decline, reduced diversity of indigenous herbaceous plant communities and loss of wildlife. Using native pastures may offer some solutions to these problems, but the level of understanding required to manage them effectively is limited. Exotic sown pastures have no clear advantage in areas with poor soils and irregular rainfall, and the environmental impacts of new developments involving large-scale pasture improvement can be unacceptable. I conclude that native and naturalised pastures are the best option for most of the region and sown pastures should be used strategically.

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19

Vere, D. T., R. E. Jones y M. H. Campbell. "Long-term change in the economic productivity of four major pasture categories on the south-eastern Tablelands of New South Wales". Rangeland Journal 23, n.º 2 (2001): 148. http://dx.doi.org/10.1071/rj01002.

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The perception of change or decline in the productivity of temperate pastures in south-eastern Australia is an important concern to livestock producers and pasture scientists. Much of this concern relates to reductions in the proportions of desirable species in the composition of pasture systems as a result of increased soil and weed problems. The purpose of this paper is to investigate trends in the long-term economic productivity of four categories of temperate pastures (all introduced pastures, introduced perennial grasses, introduced legumes and all native pastures) on the central and southern tablelands of New South Wales. The results provide evidence of economic productivity decline in the all introduced pastures category in relation to sheep production, but this has been due to productivity decline in the dominant legume component of the introduced pastures. In contrast, there has been strong growth in the economic productivity of the introduced perennial grass pastures. Abnormally high beef cattle numbers in the mid-1970s appear to have created an illusion of high productivity and subsequent decline in all introduced pastures. In contrast, the economic productivity of the native pastures which are the bulk of the region's grazing areas, has fallen substantially.

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20

Vere, D. T. y M. H. Campbell. "Potential economic benefits to the Australian wool industry from improving pastures in the hill country of eastern New South Wales". Rangeland Journal 26, n.º 2 (2004): 161. http://dx.doi.org/10.1071/rj04011.

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Large areas of undeveloped pastures in non-arable hill country in eastern New South Wales could be improved by aerial methods. The potential economic benefits of pasture improving a portion of the hill country area were evaluated in terms of the economic welfare changes in the Australian wool industry. Hill country wool producers and international wool consumers would derive nearly all of the benefits from this process. Other Australian and international wool producers would lose economic welfare because of the reduced price from increased regional wool production. For conservative anticipated levels of pasture improvement adoption, the overall benefits to the Australian wool industry had 15-year mean present values of between $30.2 million and $122.1 million, depending on whether the introduced pasture was predominantly perennial grass or legume based. The value of this analysis is that it provides improved economic information for planning investment in new pasture technologies in the Australian livestock industries.

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21

Carvalho, Bruno Humberto Rezende, Lilian Elgalise Techio Pereira, André Fischer Sbrissia, Gabriel De Oliveira Rocha y Manoel Eduardo Rozalino Santos. "Height and mowing of pasture at the end of winter modulate the tillering of Marandu palisadegrass in spring". Tropical Grasslands-Forrajes Tropicales 9, n.º 1 (30 de enero de 2021): 13–22. http://dx.doi.org/10.17138/tgft(9)13-22.

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In pastures subjected to stockpiling, the tiller population goes through an intense process of self-thinning, hindering the recruitment of new tillers in the subsequent season. We evaluated different pasture management strategies in late winter in an attempt to modify tiller recruitment during spring. Urochloa brizantha cv. Marandu was maintained at 4 different levels (heights) of stockpiled pasture at the end of winter: short (15.1 cm), medium (23.2 cm), tall (31.4 cm) and tall/mown (31.3 cm, mown to 8 cm). In October (early spring), the short and tall/mown pastures had a tiller appearance rate (TAR) and a population stability index (PSI) superior (P<0.05) to that of the tall pasture. During the remainder of the growing season, these characteristics (TAR and PSI) were similar for all pastures. Tiller survival rate (TSR) was also highest (P<0.05) in short pasture in early spring. TAR values were highest in early spring and these tillers persisted throughout the growing season. When stockpiling Marandu palisadegrass pasture during spring it is important to have it short at the end of winter to ensure early and intense tillering in spring. If pasture is tall at the end of winter mowing at this time before spelling is advantageous.

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22

Kaiser, J. "ECOLOGY: A Nasty Brew From Pasture Fires". Science 277, n.º 5330 (29 de agosto de 1997): 1205a—1205. http://dx.doi.org/10.1126/science.277.5330.1205a.

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23

Hunt, John E., Johannes Laubach, Matti Barthel, Anitra Fraser y Rebecca L. Phillips. "Carbon budgets for an irrigated intensively grazed dairy pasture and an unirrigated winter-grazed pasture". Biogeosciences 13, n.º 10 (18 de mayo de 2016): 2927–44. http://dx.doi.org/10.5194/bg-13-2927-2016.

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Abstract. Intensification of pastoral agriculture is occurring rapidly across New Zealand, including increasing use of irrigation and fertiliser application in some regions. While this enables greater gross primary production (GPP) and livestock grazing intensity, the consequences for the net ecosystem carbon budget (NECB) of the pastures are poorly known. Here, we determined the NECB over one year for an irrigated, fertilised and rotationally grazed dairy pasture and a neighbouring unirrigated, unfertilised, winter-grazed pasture. Primary terms in the NECB calculation were: net ecosystem production (NEP), biomass carbon removed by grazing cows and carbon (C) input from their excreta. Annual NEP was measured using the eddy-covariance method. Carbon removal was estimated with plate-meter measurements calibrated against biomass collections, pre- and post-grazing. Excreta deposition was calculated from animal feed intake. The intensively managed pasture gained C (NECB = 103 ± 42 g C m−2 yr−1) but would have been subject to a non-significant C loss if cattle excreta had not been returned to the pasture. The unirrigated pasture was C-neutral (NECB = −13 ± 23 g C m−2 yr−1). While annual GPP of the former was almost twice that of the latter (2679 vs. 1372 g C m−2 yr−1), ecosystem respiration differed by only 68 % between the two pastures (2271 vs. 1352 g C m−2 yr−1). The ratio of GPP to the total annual water input of the irrigated pasture was 37 % greater than that of the unirrigated pasture, i.e. the former used the water input more efficiently than the latter to produce biomass. The NECB results agree qualitatively with those from many other eddy-covariance studies of grazed grasslands, but they seem to be at odds with long-term carbon-stock studies of other New Zealand pastures.

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24

Steele, C. H., J. R. King, E. H. Boughton y D. Jenkins. "Distribution of the Red Imported Fire Ant Solenopsis invicta (Hymenoptera: Formicidae) in Central Florida Pastures". Environmental Entomology 49, n.º 4 (20 de mayo de 2020): 956–62. http://dx.doi.org/10.1093/ee/nvaa037.

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Abstract Habitat disturbance has been found to facilitate the introduction of a wide range of species, including the red imported fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae: Myrmicinae). Despite the link between S. invicta colonization and disturbance, little is known about how different intensities or types of disturbance might impact S. invicta populations. In this study, we used S. invicta populations in cattle pastures to understand how variation in disturbance type and frequency correlates with the density of S. invicta mounds. In total, 56 plots were surveyed for mound abundance during both the wet and dry seasons on a subtropical south Florida ranch. Explanatory variables were grouped into five categories based on disturbance type: 1) historic pasture conversion; 2) modern pasture management (mowing, dragging, chopping, or aerating); 3) grazing intensity (a measure vegetation height and dung pat abundance); 4) distance to human-made and natural localized disturbance (roads, ditches, and wetlands); and 5) abiotic conditions (soil temperature, soil moisture). Overall, the average number of mounds per plot was not significantly different between seasons, but was significantly higher in intensive pastures, which are converted to nonnative forage grasses than in seminative pastures during the dry season. Time since soil disturbance (aeration and chopping of pasture) was a significant predictor of S. invicta densities in both dry and wet seasons, with an increase in time since disturbance being associated with higher mound densities. Other forms of pasture management that did not disturb the soil, such as dragging and mowing, as well as distance to localized disturbances (wetlands, roads, and ditches) were not found to have a significant correlation in either season.

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25

Walsh, Dionne y Robyn A. Cowley. "Looking back in time: can safe pasture utilisation rates be determined using commercial paddock data in the Northern Territory?" Rangeland Journal 33, n.º 2 (2011): 131. http://dx.doi.org/10.1071/rj11003.

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A ‘safe’ pasture utilisation rate is defined as the proportion of annual forage growth that can be consumed by domestic livestock without adversely affecting land condition in the long term. Pasture utilisation rates are thus a cornerstone of a sustainable grazing industry because they directly determine livestock carrying capacity. Until now, it has only been possible to determine utilisation rates in the Northern Territory via expensive and time-consuming grazing trials. Reliance on this method has limited the validation of safe utilisation rates for the range of land types used for pastoral production. This study tested an alternative cost-effective method for calculating utilisation rates based on an approach used previously in Queensland. The method retrospectively calculates utilisation rates using cattle records and modelled pasture growth from commercial paddocks in good land condition. The assumption underpinning the method is that paddocks in good land condition, with a long history of grazing, must have been managed in such a way as to achieve a safe level of pasture utilisation. Utilisation rates were calculated for 10 commercial paddocks on three properties in the Barkly Tableland region of the Northern Territory from 1999 to 2009. Animal intake for each paddock was calculated from detailed cattle records held in property databases. Pasture growth was estimated using simulation models and cross-checked with field measurements. An average utilisation rate of up to 25% of annual pasture growth was found to be safe on highly uniform, grey cracking-clays supporting Mitchell grass (Astrebla F. Muell. spp.) pastures. However, this level of utilisation had negative impacts on land condition on less resilient and preferentially grazed pasture communities in paddocks with a mix of land types. The implications of the results for carrying capacity, animal productivity and seasonal risk management are explored in this paper.

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26

Couto, M. C. M., S. Quinelato, C. N. Santos, L. S. Souza, I. B. M. Saio y M. L. A. Rodrigues. "Environmental influence in cyathostominae ecology". Veterinární Medicína 53, No. 5 (13 de junio de 2008): 243–49. http://dx.doi.org/10.17221/1950-vetmed.

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Studies of the survival, recovery and migration of cyathostomin infective larvae in a Bermuda grass (Cynodon dactylon) pasture were carried out in the Baixada Fluminense county, Rio de Janeiro state. Fresh feces (± 1 kg) from naturally infected horses were deposited monthly on Bermuda grass. Samples of feces and surrounding grass were collected every seven days, from March 2005 to March 2007, and larva were counted. In the feces, cyathostomin L3 survived for up to 15 weeks, with higher recovery rates during the rainy period (46 228/kg dried herbage – dh), and on the grass for up to 12 weeks. The recovery of L3 was greater during the dry period in the grass base (1 868/kg dh) compared to the apex (809/kg dh). The migration of L3from feces to grass varied during the period. Climatic factors, such as temperature and rain, influenced the development and migratory behavior of cyathostomin L3. With regard to the grass base, significant differences were observed at the different collection times. The results demonstrate that under local conditions animals are at permanent risk since the infective larvae are always present on pasture.

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27

Hunt, L. P. "Safe pasture utilisation rates as a grazing management tool in extensively grazed tropical savannas of northern Australia". Rangeland Journal 30, n.º 3 (2008): 305. http://dx.doi.org/10.1071/rj07058.

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The concept of safe pasture utilisation rates is frequently promoted as a tool for use in setting livestock numbers in perennial grass pastures in northern Australia’s tropical savannas to achieve a grazing intensity that is ecologically and economically sustainable. However, recommended pasture utilisation rates have been defined and applied in several ways, and this has led to some confusion among managers, researchers and advisers about their appropriate use. In order to reduce this confusion, this paper reviews the ecological basis and use of safe pasture utilisation rates as a management tool, concentrating on two common ways (i.e. strategic and tactical) in which they are applied. The main objective of both approaches is to limit the intensity of grazing of perennial grasses during the growing season when they are most sensitive to defoliation. When used in a strategic way, safe pasture utilisation rates provide an indication of long-term safe stocking rates that will avoid pasture deterioration in most years. Alternatively, they are used in a tactical sense to adjust stocking rates to track forage production, usually on an annual basis. Using the tactical approach, stocking rates are set at the end of the growing season in order to use a ‘safe’ proportion of the standing forage available at that time during the subsequent 12 months. Thus, stocking rates for one growing season are based on the quantity of forage available at the end of the previous growing season. In areas with high year-to-year variability in pasture growth this may lead to overgrazing during the growing season. This paper concludes by suggesting several strategies to better manage pasture utilisation levels under a tactical management approach to ensure that palatable perennial grass populations persist in the long term. A call is also made for researchers and land management advisers to be clear in the way recommended safe pasture utilisation rates are defined and intended to be used.

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28

Orr, DM, CJ Evenson, DJ Jordan, PS Bowly, KJ Lehane y DC Cowan. "Sheep productivity in an Astrebla grassland of south-west Queensland." Rangeland Journal 10, n.º 1 (1988): 39. http://dx.doi.org/10.1071/rj9880039.

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A grazing study conducted between 1979 and 1983 assessed the seasonal trends of ewe productivity in Astrebla grassland in south- western Queensland. This study was designed originally to compare productivity on two pastures with different compositions, however, these differences in pastures composition were not achieved. Large differences in liveweight, wool growth and reproductive performance occurred between years in response to differences in pasture growth resulting from large variation in the seasonal incidence of rainfall. Rainfall effective for plant growth, both forbs and grasses, resulted in a high quality diet which resulted, in turn, in increased sheep productivity. Reproductive performance was particularly sensitive to the quality of the ewes diet around the time of lambing through the effect of diet quality on lamb survival and growth rate. It is suggested that the effect of rainfall on reproductive performance is pasture.

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29

Rakhimova, Nodira, Tashkhanim Rakhimova y Jasur S. Sadinov. "Current state of Anabasis salsa pasture varieties in Karakalpak Ustyurt (Uzbekistan) due to Aral Sea drying". Plant Science Today 9, sp3 (2 de octubre de 2022): 25–30. http://dx.doi.org/10.14719/pst.1804.

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This article is devoted to the study of the current state of 2 pasture varieties of the biyurgun type: Anabasis salsa with the participation of Caroxylon orientale, Artemisia terrae-albae and A. kemrudica; Anabasis salsa with Caroxylon orientale and Artemisia terra-albae and Convolvulus fruticosus, Lycium ruthenicum, Anabasis brachiata, Nanophyton erinaceum, Nitraria schoberi, Malacocarpus crithmifolius and Xylosalsola chiwensis, with single Crambe edentula specimens distributed across the territory of Karakalpak Ustyurt (Uzbekistan) under the influence of Aral Sea drying. The Anabasis salsa pasture type occupies a larger area than that occupied by the other pasture types in Karakalpak Ustyurt (2 664 774 ha) and accounts for 36.4% of the total territory, which includes 9 pasture varieties. This type is common on takyr, loamy saline soils and, high-gypsum soils. The area of the studied pasture varieties, soil cover nature, projective cover percentage, landscape plant species, species placement, forage yield and recommended seasonality of use were determined. According to our observations the investigated pasture varieties are recommended for use as autumn-winter pastures.

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Zhang, B., G. Fraser, J. Carter, G. Stone, S. Irvine, G. Whish, J. Willcocks y G. McKeon. "An online system for calculating and delivering long-term carrying capacity information for Queensland grazing properties. Part 2: modelling and outputs". Rangeland Journal 43, n.º 3 (2021): 159. http://dx.doi.org/10.1071/rj20088.

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A combination of field data and models have been used to estimate long-term carrying capacity (LTCC) of domestic livestock in Queensland grazing lands. These methods have been synthesised and coupled with recent developments in science and information technology to provide a fully-automated approach of modelling LTCC through the FORAGE online system. In this study, the GRASP model was used to simulate pasture growth with parameter sets and safe pasture utilisation rates defined for 225 land types across Queensland. Distance to water points was used to assess the accessibility of pastures to livestock. Spatial analysis classified the property into unique areas based on paddock, land type and distance to water points, which estimated pasture growth, pasture utilisation and accessibility at a sub-paddock scale. Thirteen foliage projective cover (FPC) classes were used in modelling the pasture system to deal with the non-linear relationship between tree and grass interactions. As ‘proof of concept’, remotely-sensed individual-date green ground cover data were used to optimise the GRASP model parameters to improve the model performance, and a Monte Carlo analysis provided uncertainty estimates for model outcomes. The framework provides an efficient and standardised method for estimating LTCC. To test the system, LTCCs from 43 ‘benchmark’ properties were compared with simulated LTCCs, and 65% of the modelled LTCCs were within ± 25% of the benchmark LTCCs. Due to uncertainties in model inputs at the property scale and in model simulation, the modelled LTCC should be used as a starting point for further refinement of actual property LTCC.

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31

Lyons-Galante, Hannah Ruth y Xavier Haro-Carrión. "Effect of distance from edge on exotic grass abundance in tropical dry forests bordering pastures in Ecuador". Journal of Tropical Ecology 33, n.º 2 (marzo de 2017): 170–73. http://dx.doi.org/10.1017/s0266467417000062.

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Abstract:We compared exotic pasture grass cover near the edges of 20–25-y-old secondary forests (N = 8) with those of mature forests (N = 8), bordering actively grazed pastures on the Pacific Coast of Ecuador. We estimated grass cover in 224 1 × 3-m plots along transects that ran from the pasture edge into forest interiors (11–44 m). Using a spline regression, we divided the transects into three segments: exterior (in the pasture), edge and interior (in the forest). With a stepwise regression, we tested the effect of transect section, forest type and distance from edge on grass cover. Forest type, distance from edge, interior transect section and the combined effect of distance from edge in both the interior and exterior sections explained variation in grass cover. Grass abundance was higher and penetrated further into secondary than mature forests. Edge proximity and differences in forest canopy openness likely favours recruitment and persistence of pasture grasses.

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32

Cervantes-Pasqualli, Juan Alberto y Javier Laborde. "Fig development in two Neotropical Ficus species, Ficus (subg. Pharmacosycea) yoponensis and Ficus (subg. Spherosuke) colubrinae: comparing rainforest and pasture trees". Botany 99, n.º 8 (agosto de 2021): 475–89. http://dx.doi.org/10.1139/cjb-2020-0139.

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In the fragmented landscape of Los Tuxtlas, adult fig trees are found in both rainforest remnants and in pastures. Syconium (fig) development is known to vary between and within Ficus species, but it is not known whether it differs between rainforest and pasture trees. Here, we describe syconium development for two Ficus species with different life forms (free-standing and hemi-epiphytic) in two contrasting, adjacent habitats: an undisturbed rainforest and active pastures. Over three months, we monitored 15 reproductive events in Ficus (subg. Pharmacosycea) yoponensis Desv. and Ficus (subg. Spherosuke) colubrinae Standl., collecting and dissecting syconia every 3–4 days (1291 and 815 syconia per species, respectively). External and internal structural changes in the syconia are described, including foundress occurrence and the maximum duration of the receptive phase while waiting for pollinators. The duration of both the reproductive events (<8 weeks) and the developmental phases in the two species did not differ between rainforest and pasture trees and are within the lower range of time reported for other Ficus species. After pollinator exclusion, the receptive phase lasted up to four times its normal duration. Syconia were slightly larger in rainforest trees than in pasture trees, and the infestation of F. yoponensis syconia by non-pollinating insects was higher in rainforest trees.

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33

Sheldon, Kimberly S. y Nalini M. Nadkarni. "The use of pasture trees by birds in a tropical montane landscape in Monteverde, Costa Rica". Journal of Tropical Ecology 29, n.º 5 (septiembre de 2013): 459–62. http://dx.doi.org/10.1017/s0266467413000503.

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Abstract:Conversion of forests to agricultural land may require many bird species to use resources in fragmented landscapes in order to persist. Pasture trees can make agricultural landscapes more hospitable for birds, but we do not know what factors promote bird visitation to pasture trees. Bird use of 26 focal trees of a common pasture species, Sapium glandulosum (Euphorbiaceae), was examined in three pastures in a montane landscape in Costa Rica to understand factors influencing bird visitation. Bird visits were analysed in relation to pasture tree size, distance from forest edge, degree of isolation and epiphyte load. Foraging resources (epiphyte or tree substrate) were also measured. From May–July 2012, 52 bird species from 20 families were recorded from 926 unique visits. Bird visitation was best explained by tree size, degree of isolation and epiphyte load such that larger, more isolated trees with higher epiphyte loads attracted more birds. Birds preferred food resources from focal trees (51% of visits) rather than their epiphytes (5% of visits). The results corroborate previous findings that mature pasture trees, even when isolated, may contribute more to species persistence than smaller trees.

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34

Coates, D. B. y R. M. Dixon. "Faecal near infrared reflectance spectroscopy (F.NIRS) measurements of non-grass proportions in the diet of cattle grazing tropical rangelands". Rangeland Journal 29, n.º 1 (2007): 51. http://dx.doi.org/10.1071/rj07011.

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Frequent faecal near infrared reflectance spectroscopy (F.NIRS) analyses of faeces from cattle grazing a range of tropical pastures were used to measure the non-grass component, and other aspects, of their diets. Seasonal profiles of non-grass and crude protein in the diet are presented for nine sites from the speargrass, Aristida–Bothriochloa, and Mitchell grass dominated pasture regions, and for three shrubland sites where browse was plentiful. In grass-dominated native pastures of the speargrass and Aristida–Bothriochloa pasture regions of Queensland where little browse was available, non-grass was usually only 5–15% of the diet. Diet non-grass was even lower for a buffel grass pasture. In uncleared eucalypt woodland in the speargrass region, browse may have contributed up to 20% of the diet in the late dry season when grasses were senesced. In regions with abundant browse (e.g. mulga lands and desert upland systems) cattle preferentially selected actively growing grasses and forbs when they were available. With diminishing availability or declining quality of the forbs and grass due to grazing selection and dry conditions, browse increasingly contributed to intake. In Mitchell grass dominated pastures forbs often comprised more than 50% of the diet, and there appeared to be strong selection for forbs during the dry season. Where browse was available in association with Mitchell grass dominated pastures, it appeared to contribute to intake only in the late dry season. Dry season sampling in monsoonal tallgrass and Mitchell grass dominated pastures indicated dietary crude protein to be linearly correlated with diet non-grass, demonstrating the importance of non-grass in the prevention or alleviation of dry season protein deficiency in cattle. Changes in diet selected by cattle in relation to season and rainfall were generally in accord with the previous limited information, largely with sheep, in comparable vegetation systems. The results demonstrate the value of F.NIRS technology to assist understanding of diet selection by grazing cattle in northern Australia.

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35

Nasiyev, Beybit, Askhat Bekkaliyev, Ivan Manolov y Vladimir Shibaikin. "Influence of grazing technologies on the indices of chestnut soils in Western Kazakhstan". Polish Journal of Soil Science 53, n.º 1 (22 de junio de 2020): 163. http://dx.doi.org/10.17951/pjss.2020.53.1.163.

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Degradation of pastures caused by anthropogenic and climatic factors leads to desertification, loss of soil fertility, reduces productivity of the pasture grass and it is a prerequisite for socio-economic problems. Pastures of Western Kazakhstan cover more than 70% of the lands under economic use and are the main fodder source for the farm animals. In the late years, degradation of pastures in Western Kazakhstan takes place due to intensive animal grazing. The aim of research is to study the impact of technology for grazing the farm animals on the pastures soil cover to prevent the processes of degradation and desertification, as well as the rational use of pasture ecosystems. Through these studies, experimental data were obtained on the current state of the pastures soil cover in Western Kazakhstan with different types of chestnut soils depending on the grazing technology. An excess intensive grazing of the farm animals has negative influence on physical and chemical factors of the chestnut soil types.

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36

Kumar, Sunil, Anoop Kumar Dixit, Mahendra Prasad, Suchit Kumar Rai, Sanat Kumar Mahanta, Sultan Singh, Sudesh Radotra y Probir Kumar Ghosh. "Effects of grazing intensity and pasture type on soil organic carbon stock in the semi-arid tropics of India". Tropical Grasslands-Forrajes Tropicales 11, n.º 1 (31 de enero de 2023): 41–51. http://dx.doi.org/10.17138/tgft(11)41-51.

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Pastures may act as carbon sources and sinks depending on grazing pressure and management practices. Soil organic carbon (SOC) stock and its fractions were quantified under 3 different grazing intensities using 5, 10 and 15 sheep/ha under sown, improved and natural pastures in the semi-arid tropics of India. Results revealed that after 3 years, improved pasture had significantly higher particulate organic carbon (POC ~4.5 g/kg), SOC (~0.53 %), total organic carbon (TOC~7 g/kg) and SOC stock (~15 mg/ha) as compared with sown and natural pastures. Labile carbon (LC ~185 mg/kg) and soil microbial biomass carbon (SMBC ~378 µg/g soil) were higher under natural pasture. A moderate grazing intensity of 10 sheep/ha resulted in significantly greater carbon fractions, TOC and SOC stock. SOC stock and its fractions were significantly higher in the topsoil layers as compared with the subsoil layers. These results indicate that improved pasture management practices with moderate grazing intensity can be recommended for improving SOC stock and its fractions in semi-arid tropical pastures.

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37

Vere, D. y P. Dowling. "An economic analysis of sown pasture trends on the tablelands of south-eastern New South Wales". Rangeland Journal 25, n.º 1 (2003): 56. http://dx.doi.org/10.1071/rj03005.

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The latter part of the 20th century has seen a persistent decline in the productivity of some types of sown pastures on the central and southern tablelands of New South Wales. Currently, much research effort is directed to stabilising the perennial grass component of these pastures. This paper evaluates the economic justification of that emphasis. It is argued that trends in livestock production can usefully represent increases or decreases in the stocks of three broad categories of sown pastures that are defined as being those pastures sown to introduced perennial grasses and legumes (perennial grasses), introduced legumes only (legumes), and the total of both these categories. Regression methods were used to determine the changes that have occurred in the livestock production from these pastures that could be explained by changes in a range of economic and other variables. The estimated models were then used to forecast wool, beef and lamb production from each pasture type. The results indicate that changes in prices and costs have influenced the trends in animal production from these pastures and that the structures of these influences have changed over time. Production from perennial grass-legume pastures has remained high relative to production from legume pastures despite adverse cost-price trends. The forecasts indicated a continuation of present levels of perennial grass-legume pasture areas but a decline in production from the legume pastures. The results support the concerns about the continued deterioration in the legume only pastures and the thrust of R&D programs that promote the benefits of perennial grass-legume pastures. The use and analysis of public data to improve understanding of the economic factors that influence the long-term stability of intensively grazed rangelands is highlighted.

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38

Guy, P. L. "Viruses of New Zealand pasture grasses and legumes: a review". Crop and Pasture Science 65, n.º 9 (2014): 841. http://dx.doi.org/10.1071/cp14017.

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This article reviews knowledge of 23 plant viruses infecting pasture grasses and legumes in New Zealand. The incidence, ecology and impact of each virus and prospects for control using natural or artificial resistance genes or by vector control is discussed. The most prevalent viruses are Alfalfa mosaic virus and White clover mosaic virus in pasture legumes and Cocksfoot mottle virus, Ryegrass mosaic virus and Barley yellow dwarf virus in pasture grasses. Lucerne Australian latent virus is restricted to the North Island and Red clover necrotic mosaic virus is largely restricted to the South Island. These patterns are likely to be dynamic with ongoing changes in weather patterns, land use, the spread of insect vectors and the continuing introduction of viruses and vectors. The existing and potential threats to 12 pasture species are tabulated and the knowledge gaps for each species highlighted. Control of vectors including aphids, eriophyid mites and soil-borne fungi is probably not economic per se but could be an additional benefit of integrated pest management in pasture and cropping systems. The most cost-effective and practical preventative measures are likely to be the use of virus-tested seed to establish new pastures and the incorporation of resistance genes by conventional breeding or by genetic engineering. Finally, recommendations are made for future research for New Zealand, which is also relevant to other temperate regions of the world.

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Mazzocchi, Chiara, Guido Sali y Giordano Ruggeri. "Tourists’ Preferences for Alpine Pastures Maintenance". Landscape Online 68 (18 de mayo de 2019): 1–18. http://dx.doi.org/10.3097/lo.201968.

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Traditional extensive agriculture is the main factor of landscape management in the mountains: a large part of the Alps is modelled by agriculture. Interpreted as a multifunctional activity, including landscape modelling and maintenance, agriculture generates the conditions under which mountain pasture landscape is an economic resource potentially exploitable by tourism. The aim of this work is to draw the profiles of tourists of mountain pastures and to estimate their Willingness to Pay (WTP)for landscape pastures resilience. The innovation of this work lies in the use of a multivariate approach using Contingent Valuation Method (CVM), Multiple Correspondence Analysis (MCA) and Hierarchical Cluster Analysis (HCA). The analysis obtained three clusters that identify different tourists’ profiles. The main result is the existence of a positive WTP for the permanence of pasture systems with an agricultural management. Policy guidelines have been proposed to institutions owning pastures and huts to manage these assets.

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Smetham, Michael L. "The Management of Pastures for Grazing". Outlook on Agriculture 24, n.º 3 (septiembre de 1995): 167–77. http://dx.doi.org/10.1177/003072709502400307.

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This article examines pasture management in moist temperate climates, and looks at the reasons why putting the findings into practice has been so difficult. Many factors affect the behaviour of the animal-pasture system, including whether continuous or rotational grazing is practised, the intensity of grazing, and seasonal differences in climate and grass reproduction. Pasture quality is defined in terms of green leaf and dead material: the amount of green leaf present in a pasture is of prime importance in determining the productivity of the canopy and its value for animal feeding, while the presence of dead material can interfere with herbage productivity and also reduce the quality of the sward for animals. Pastures and grazing animals interact strongly with each other, and maximum productivity depends on achieving a balance.

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Jarman, PJ, CN Johnson, CJ Southwell y R. Stuartdick. "Macropod Studies at Wallaby Creek .1. The Area and Animals". Wildlife Research 14, n.º 1 (1987): 1. http://dx.doi.org/10.1071/wr9870001.

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This paper introduces a series of papers on the ecology, social organisation and behaviour of populations of sympatric macropods (Macropodoidea : Marsupialia) in north-eastern New South Wales. The study site, in the valley of Wallaby Creek, covers partly tree-cleared cattle-grazed pastures and also wet and dry forest communities; 10 species of macropods live there. The valley has a moderately high rainfall (1023 mm per annum), falling predominately in summer, and an equable climate of cool winters and warm summers. Soils derived from sedimentary and basaltic rocks and alluvium support naturally diverse plant associations further diversified by clearing and establishment of pasture and weed species. Macropods favouring open country occupy the pastures, which can also be used by cover-dependent species where pasture abuts forest or remnant patches of cover. Composition of the macropod community has changed since development of the pasture zone. Dingoes, major predators of some of the macropods, are abundant, and all exotic mammals other than cattle are rare. Populations of two of the macropod species are habituated to approach by observers, and close observation, on foot, of undisturbed animals has become our common study technique. A 1-ha grid has been established over 3.7 km2 of the study site to facilitate exact location of animals and observations. The suitability of the macropod populations for this kind of study results from the attitudes of the landholders.

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Zydenbos, S. M., B. I. P. Barratt, N. L. Bell, C. M. Ferguson, P. J. Gerard, M. R. Mcneill, C. B. Phillips, R. J. Townsend y T. A. Jackson. "The impact of invertebrate pests on pasture persistence and their interrelationship with biotic and abiotic factors". NZGA: Research and Practice Series 15 (1 de enero de 2011): 109–17. http://dx.doi.org/10.33584/rps.15.2011.3203.

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New Zealand pastures are host to a range of native and exotic invertebrates. Many of these are pests that feed on the sown plant species, often causing plant death and deterioration in the productivity and persistence of the sward. While most research has focused on pest biology and control, studies of plant productivity show dramatic acute (short-medium term) and chronic (longterm) effects. For example, grass grub has been reported to cause 50% losses to ryegrass swards and Argentine stem weevil can cause a 20% loss of productivity, but the long term effects through loss of the sown species and changes in composition can be even more severe. Insect damage can be exacerbated by other biotic (e.g. weed invasion, grazing animals, plant pathogens) or abiotic factors (e.g. climate, soil fertility) to further reduce plant persistence. Some biotic and abiotic factors may interact with insect pests to have positive effects on pasture persistence, e.g. biocontrol agents that reduce pest density or addition of fertiliser to enable plants to recover from insect damage. For many pasture pests, knowledge of their ecology is based on research from over 20 years ago that, while still valid, needs to be updated to account for modern intensive pasture management practices, such as intensive grazing with a lack of reseeding, and new cultivars. To improve pasture persistence, integrated research programmes are needed that examine the relative importance of all factors contributing to plant survival and develop strategies to mitigate their effects. Keywords: Argentine stem weevil, black beetle, clover root weevil, drought, grass grub, grazing pressure, manuka beetle, nematodes, pasture persistence, pasture quality, pasture yield, porina, soil fertility, striped chafer.

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Silcock, R. G., T. J. Hall, P. Jones, P. G. Filet y J. Douglas. "Spring fire effects on two Aristida/Bothriochloa native pastures in central Queensland, Australia". Rangeland Journal 40, n.º 5 (2018): 485. http://dx.doi.org/10.1071/rj17132.

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Controlled burns are commonly used to suppress woody plant regrowth and to remove accumulated unpalatable pasture from rangelands and occasionally to alter pasture composition in native pastures in central Queensland, Australia. Outcomes can be somewhat unpredictable and short-term, and reliable evidence is needed to confirm the likely long-term efficacy of such fires. We imposed a regime of repeated spring burns on native Aristida/Bothriochloa pastures growing in two contrasting eucalypt woodlands of central Queensland to determine the effects on pasture composition, ground cover, landscape stability and woody plant recruitment, all in the absence of grazing. The sites selected were a silver-leaved ironbark (Eucalyptus melanophloia F.Muell.) woodland and a poplar box (E. populnea F.Muell.) woodland. Weather conditions precluded spring burns in 3 years out of 7 at the silver-leaved ironbark site and in 2 years out of 8 at the poplar box site. The burn intensity was variable, and frequent fires produced a marked change in abundance of only a few pasture species. Depending on the site, fires significantly increased the frequency of Enneapogon spp., Bothriochloa bladhii (Retz.) S.T.Blake and Dichanthium sericeum (R.Br.) A.Camus and reduced the frequency of some minor components such as Cymbopogon spp., Panicum effusum R.Br., Cenchrus ciliaris L. and, ephemerally, that of some forbs. Contrary to expectation, only Aristida calycina R.Br. declined in abundance among the many Aristida species present, and the abundance of Heteropogon contortus (L.) P.Beauv. ex Roem. & Schult. barely increased under regular spring fires. The total germinable seeds of herbaceous species in the soil each spring was significantly reduced by burning in the previous spring. Repeated spring fires rarely reinforced any initial change induced by burning, and slightly lowered average ground cover as well as various indices of landscape stability and ecosystem functionality. Changes produced were not always consistent across the two communities. Though prescribed burning is often important for maintaining grazing productivity and landscape values, very regular use is not recommended.

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Correa, César M. A., Anderson Puker y Alfredo R. Abot. "Impacts of Exotic Pasture Establishment on Dung Beetle Assemblages (Coleoptera: Scarabaeidae: Scarabaeinae) in the Brazilian Cerrado". Environmental Entomology 49, n.º 6 (7 de noviembre de 2020): 1335–44. http://dx.doi.org/10.1093/ee/nvaa132.

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Abstract The Brazilian Cerrado is the second largest Neotropical biome and an important hotspot of biodiversity. However, land use change in this ecosystem is producing landscapes with modified natural environments and anthropogenic environments, such as exotic pastures. In this study, we evaluated how conversion of native Cerrado vegetation to exotic pastures affects the dung beetle assemblages (Coleoptera: Scarabaeidae: Scarabaeinae). We sampled dung beetles in four areas of Cerrado (sensu stricto) and in four areas of exotic pastures (Urochloa spp.) in Aquidauana, Mato Grosso do Sul, Brazil. In all, 7,544 individuals from 43 species of dung beetles were collected, and 19 species were found in both the Cerrado and exotic pastures. The abundance and species richness of dung beetles were higher in Cerrado remnants. Species composition differed between Cerrado and exotic pastures, where 11 species were classified as specialists of Cerrado, 10 species were considered specialists of exotic pastures, and 6 species were habitat generalists. Roller beetles were most negatively affected by exotic pasture establishment. We demonstrated that exotic pasture establishment has a negative impact on dung beetle assemblages in Brazilian Cerrado. The decline in abundance and richness of roller beetles has important implications for the understanding of ecosystem functioning because it can reduce the ecological functions performed by dung beetle assemblages in exotic pastures. Finally, the high number of dung beetle species shared between Cerrado and exotic pastures suggests that the Cerrado remnants is a fundamental requirement for the conservation of biodiversity of dung beetles in exotic pastures in the Brazilian Cerrado.

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McCosker, TH, PK O'Rourke, AR Eggington y FW Doyle. "Soil and plant relationships with cattle production on a property scale in the monsoonal tallgrass tropics." Rangeland Journal 10, n.º 1 (1988): 18. http://dx.doi.org/10.1071/rj9880018.

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Extreme variability in cattle production between replicate paddocks in a large supplementation experiment on Mount Bundey Station in the Danvin pastoral district of the Northern Territory, led to a search for reasons for the differences. Soil type, land unit and pasture parameters were related to cattle production parameters. Pregnancy rates of lactating heifers were positively related to yields of Themeda triandra, Sorghum plumosum, Eriachne burkittii and Eragrostis spp., the fist three of which declined in yield following heavy grazing pressure. Quantity of pasture was more closely correlated with animal production than was quality due to the wide range in yields and narrow range in quality attributes. Pregnancy rate in lactating heifers was more sensitive to yield of pasture species than was lactating cow pregnancy rate, breeder mortality, calf weight per breeder mated or steer average daily gain. Heifers consumed less supplement relative to their requirements than mature cows and steers and their response was not confounded by previous history. These factors probably account for their greater sensitivity to pasture variations. Pregnancy rate of cows was positively related to the proportion of lowland soil types and negatively to proportion of lithosol (hills). An equation incorporating the percentages of these soils, explained 63%. 42% and 39% of the variation in lactating cow pregnancy rate in 1982, 1983 and 1984 respectively. Variation in pregnancy rate among paddocks was therefore largely attributed to variation in the proportions of "upland" and "lowland" soil types. Sensitivity to grazing pressure of species within the native pasture was indicated by localized damage to T. triandra and S. plumosum and a large reduction in yield of Sintrans after five years of continuous grazing with access to non-protein nitrogen supplements at one breeder to 14ha. Native pastures in the Adelaide River area would not sustain this stocking rate. 18

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Glass, Nicholas, Brenda Molano-Flores, Eduardo Dias de Oliveira, Erika Meraz, Samira Umar, Christopher J. Whelan y Miquel A. Gonzalez-Meler. "Does Pastoral Land-Use Legacy Influence Topsoil Carbon and Nitrogen Accrual Rates in Tallgrass Prairie Restorations?" Land 10, n.º 7 (13 de julio de 2021): 735. http://dx.doi.org/10.3390/land10070735.

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Restoration can recover degraded ecosystems and ecosystem services. However, effects of restoration on soil nutrient accrual are difficult to predict, partly because prior land use affects rates of soil nutrient recovery. In tallgrass prairie restorations, land-use legacy effects have not yet been quantified. We investigated topsoil carbon and nitrogen accrual within seven land-use histories: (1) row crop agriculture, (2) pasture, (3) pasture converted from row crops, (4) prairie restored from row crop, (5) prairie restored from old pasture, (6) bison prairie restored from pasture and row crops, and (7) remnant prairie. Soil samples were collected in 2008 and again in 2018 at Midewin National Tallgrass Prairie in Will County, IL. Soil samples were analyzed for bulk density, root chemistry, macro- and micronutrients, and carbon. Restored prairies contained similar soil bulk densities and rates of topsoil carbon accrual compared to each other in 2018. However, restorations from row cropping accrued nitrogen more slowly than restorations from pastures. Additionally, pastures converted from crop fields exhibited fewer legacy effects than restorations converted from crop fields. This research illustrates land-use legacy effects on soil and nutrients during grassland restorations, with implications for potential restoration trajectories and their role in carbon sequestration and ecosystem functioning.

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Skroblin, Anja, Sarah Legge, Terry Webb y Leigh P. Hunt. "EcoFire: regional-scale prescribed burning increases the annual carrying capacity of livestock on pastoral properties by reducing pasture loss from wildfire". Rangeland Journal 36, n.º 2 (2014): 133. http://dx.doi.org/10.1071/rj13095.

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Prescribed burning is an important management tool in the extensive pastoral lands in northern Australia. It can be used to influence grazing patterns, increase the nutritive value of pastures, reduce the density of woody shrubs and reduce the risk of damaging wildfires. The consequences of regional-scale prescribed burning on pasture availability and annual carrying capacities of pastoral properties in northern Australia were examined using EcoFire, a fire management program in the Kimberley Region of north-west Australia, as an example. Theoretical long-term carrying capacities of land systems, and fire scar imagery from years before (2004–06) and during EcoFire (2007–11) were used to model the impact of the program on the seasonality and extent of fire-induced losses in annual carrying capacity, and the likelihood of properties experiencing catastrophic losses in a given year. Over the 5 years that EcoFire has been running, it has resulted in a progressive reduction in the loss of annual carrying capacity caused by the burning of pasture, and shifted the season that annual carrying capacity is lost to fire from predominantly the late to the early dry season. Most notably, the established program has reduced the probability of experiencing catastrophic loss (defined here as >50% of annual carrying capacity removed due to fire) from 18 incidences to three incidences within a 3-year period. These outcomes have the potential to deliver economic benefits to pastoralists via increased annual carrying capacity and by improvements in pasture condition, provided stocking rates and pasture utilisation are managed carefully.

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Bebawi, Faiz F., Shane D. Campbell y Robert J. Mayer. "Can competition with pasture be used to manipulate bellyache bush (Jatropha gossypiifolia L.) population biology?" Rangeland Journal 35, n.º 4 (2013): 393. http://dx.doi.org/10.1071/rj13011.

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Bellyache bush (Jatropha gossypiifolia L.) is an invasive weed that poses economic and environmental problems in northern Australia. Competition between pasture and bellyache bush was examined in North Queensland using combinations of five pasture treatments (uncut (control); cut as low, medium, and high pasture; and no pasture) and four bellyache bush densities (0, 2, 6 and 12 plants m−2) in a buffel grass (Cenchrus ciliaris L.) dominated pasture. The pasture treatments were applied approximately once per year but no treatments were applied directly to the bellyache bush plants. Measurements of bellyache bush flowering, seed formation, and mortality were undertaken over a 9-year period, along with monitoring the pasture basal cover and plant species diversity. Maximum flowering rates of bellyache bush occurred after 9 years (97%) in plots containing no pasture, with the lowest rates of 9% in uncut control plots. Earliest flowering (322 days after planting) and seed formation (411 days) also occurred in plots with no pasture compared with all other pasture treatments (range 1314–1393 days for seed formation to occur). No seeds were produced in uncut plots. At the end of 9 years, mortality rates of bellyache bush plants initially planted averaged ≥73% for treatments with some pasture compared with 55% under the no-pasture treatment. The percentage of herbaceous plant basal cover in uncut plots was increased 5-fold after 9 years, much greater than the average 2% increase recorded across the low, medium, and high pasture treatments. The number of herbaceous species in uncut plots remained largely unchanged, whereas there was an average reduction of 46% in the cut pasture treatments. Buffel grass remained the species with the greatest basal cover across all cut pasture treatments, followed by sabi grass (Urochloa mosambicensis (Hack.) Dandy) and then red Natal grass (Melinis repens (Willd.) Ziska). These results suggest that grazing strategies that maintain a healthy and competitive pasture layer may contribute to reducing the rate of spread of bellyache bush and complement traditional control techniques such as the use of herbicides.

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Fernandes, Geraldo Wilson y Daniel Negreiros. "A comunidade de insetos galhadores da RPPN Fazenda Bulcão, Aimorés, Minas Gerais, Brasil". Lundiana: International Journal of Biodiversity 7, n.º 2 (28 de junio de 2007): 111–20. http://dx.doi.org/10.35699/2675-5327.2006.23075.

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The galling insect community in a disturbed area of Atlantic rain forest is described for the first time in the context of environmental restoration in the RPPN Fazenda Bulcão, Minas Gerais, Brazil. We provide information on the external morphology of the galls, their occurrence on host plant organs, host plant species, and habitat types were they were collected. We sampled galls in three different habitats: abandoned pasture, secondary succession vegetation, and secondary succession vegetation dominated by Miracruodon urundeuva (Anacardiaceae), totaling 22 sites. Within these sites we encountered 29 gall morphotypes associated to 24 host-plant species. The majority of the galls (93%) were induced by Cecidomyiidae (Diptera). Abandoned pastures contained the greatest gall-species richness (19 morphotypes), followed by secondary succession vegetation dominated by M. urundeuva (16 morphotypes) and secondary succession vegetation (10 morphotypes). The diversity of galling insects encountered at Fazenda Bulcão was considered very low in comparison to that of the entire mid Rio Doce region. Keywords: abandoned pasture, bioindicators, galling insects, Atlantic rain forest, restoration ecology.

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Whalley, R. D. B., D. A. Friend, P. Sanford y M. L. Mitchell. "Evaluation of native and introduced grasses for low-input pastures in temperate Australia: rationale and scope". Rangeland Journal 27, n.º 1 (2005): 1. http://dx.doi.org/10.1071/rj05004.

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The historical approach to pasture improvement in the high rainfall zone of temperate Australia has been to add introduced herbaceous legumes and to replace perennial native grasses with introduced species requiring high inputs of fertiliser for maintenance. The application of this high-input approach on land with low capability has lead to the loss of perennial grasses, erosion, soil acidification and increasing salinity on the lower slopes. This model of pasture improvement has not been successful on the margins of the wheat belt and in semi-arid regions. The Native and Low-input Grasses Network (NLIGN) was established in 1996 to coordinate research on grasses suitable for land with low capability and for semi-arid regions. The NLIGN multi-site evaluation project was initiated to test promising lines (accessions) of native and introduced grasses for low-input pastures at eight sites across southern Australia. The broad objective of the project was to identify native and/or introduced perennial grass lines that had possible commercial potential for low-input pastures. This objective was achieved in an initial 3-year evaluation phase, which began in 1998 and tested lines for persistence, production and palatability.

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