D. M. Orr ^{A C} and D. G. Phelps ^B 

 

^A Department of Agriculture, Fisheries and Forestry, PO Box 6014, Red Hill, Rockhampton, Qld 4701, Australia. 

^B Department of Agriculture, Fisheries and Forestry, PO Box 519, Longreach, Qld 4730, Australia. 

^C Corresponding author. Email: david.orr@daff.qld.gov.au 

 

The Rangeland Journal 35(1) 1-15 http://dx.doi.org/10.1071/RJ11068

Submitted: 17 October 2011  Accepted: 14 February 2013   Published: 8 March 2013

 

Managing large variations in herbage production, resulting from highly variable seasonal rainfall, provides a major challenge for the sustainable management of Astrebla (Mitchell grass) grasslands in Australia. A grazing study with sheep was conducted between 1984 and 2010 on an Astrebla grassland in northern Queensland to describe the effects of a range of levels of utilisation of the herbage at the end of the summer growing season (April–May in northern Australia) on the sustainability of these grasslands. In unreplicated paddocks, sheep numbers were adjusted annually to achieve 0, 10, 20, 30, 50 and 80% utilisation of the herbage mass at the end of the summer over the ensuing 12 months. Higher levels of utilisation reduced both total and Astrebla spp. herbage mass because of the effects of higher utilisation on Astrebla spp. and this effect was accentuated by drought. The tussock density of Astrebla spp. varied widely among years but with few treatment differences until 2005 when density was reduced at the 50% level of utilisation. A major change in density resulted from a large recruitment of Astrebla spp. in 1989 that influenced its density for the remainder of the study. Basal area of the tussocks fluctuated among years, with increases due to rainfall and decreases during droughts. Seasonal rainfall was more influential than level of utilisation in changes to the basal area of perennial grasses. Drought resulted in the death of Astrebla spp. tussocks and this effect was accentuated at higher levels of utilisation. A series of three grazing exclosures were used to examine the recovery of the density and basal area of Astrebla spp. after it had been reduced by 80% utilisation over the preceding 9 years. This recovery study indicated that, although grazing exclusion was useful in the recovery of Astrebla spp., above-average rainfall was the major factor driving increases in the basal area of perennial grasses. Spring values of the Southern Oscillation Index and associated rainfall probabilities were considered to have potential for understanding the dynamics of Astrebla spp. It was concluded that Astrebla grassland remained sustainable after 26 years when grazed at up to 30% utilisation, while, at 50% utilisation, they became unsustainable after 20 years. Results from this study emphasised the need to maintain the population of Astrebla spp. tussocks.

 

Additional keywords: Astrebla spp., ecosystem processes, pasture dynamics, utilisation.

 

 

 

 

 D. M. Orr ^{A C} and D. G. Phelps ^B 

 

^A Department of Agriculture, Fisheries and Forestry, PO Box 6014, Red Hill, Rockhampton, Qld 4701, Australia. 

^B Department of Agriculture, Fisheries and Forestry, PO Box 519, Longreach, Qld 4730, Australia. 

^C Corresponding author. Email: david.orr@daff.qld.gov.au 

 

The Rangeland Journal 35(1) 17-28 http://dx.doi.org/10.1071/RJ11069

Submitted: 17 October 2011  Accepted: 24 January 2013   Published: 8 March 2013

 

The occurrence of interstitial species in Astrebla grasslands in Australia are influenced by grazing and seasonal rainfall but the interactions of these two influences are complex. This paper describes three studies aimed at determining and explaining the changes in plant species richness and abundance of the interstitial species in a long-term sheep utilisation experiment in an Astrebla grassland in northern Queensland. In the first study, increasing utilisation increased the frequency of Dactyloctenium radulans (Button grass) and Brachyachne convergens (Downs couch) and reduced that of Streptoglossa adscendens (Mint bush). In the second study, seasonal rainfall variation between 1984 and 2009 resulted in large annual differences in the size of the seed banks of many species, but increasing utilisation consistently reduced the seed bank of species such as Astrebla spp. and S. adscendens and increased that of species such as B. convergens, D. radulans, Amaranthus mitchellii (Boggabri) and Boerhavia sp. (Tar vine). In the third study, the highest species richness occurred at the lightest utilisation because of the presence of a range of palatable forbs, especially legumes. Species richness was reduced as utilisation increased. Species richness in the grazing exclosure was low and similar to that at the heaviest utilisation where there was a reduction in the presence of palatable forb species. The pattern of highest species richness at the lightest grazing treatment was maintained across three sampling times, even with different amounts of seasonal rainfall, but there was a large yearly variation in both the density and frequency of many species. It was concluded that the maintenance of highest species richness at the lightest utilisation was not aligned with other data from this grazing experiment which indicated that the maximum sustainable wool production occurred at moderate utilisation.

 

Additional keywords: seasonal variation, soil seed banks, species frequency, utilisation.

 

 

 

 

H. Haftay ^{A, T} Yayneshet  ^{B,C D}, G. Animut ^A and A. C. Treydte ^C 

 

^A School of Animal and Rangeland Science, Haramaya University, PO Box 138, Dire Dawa, Ethiopia. 

^B Department of Animal, Rangeland and Wildlife Sciences, Mekelle University, PO Box 231, Mekelle, Ethiopia. 

^C Agroecology in the Tropics and Subtropics, University of Hohenheim, Garbenstr 13, 70599 Stuttgart, Germany. 

^D Corresponding author. Email: yayneshet_tesfay@yahoo.com 

 

The Rangeland Journal 35(1) 29-36 http://dx.doi.org/10.1071/RJ12054

Submitted: 22 November 2012  Accepted: 31 December 2012   Published: 18 February 2013

 

Enclosures are widely used by pastoralists in East Africa. However, the response of herbaceous and woody vegetation to enclosures seasonally grazed by livestock remains poorly understood. This study investigated the effectiveness of traditional enclosures in improving herbaceous and woody vegetation in the Somali Regional State of eastern Ethiopia. Vegetation composition (species composition, diversity and richness) and structure (herbage mass, density and canopy cover) were measured inside and outside a set of enclosures. The enclosures contained higher numbers of desirable species than the adjacent open-access grazing areas. Woody species richness was higher in the open-access grazing areas than in the enclosures, which is attributed to the manual removal of most of the undesirable shrubs and trees in the enclosures by pastoralists. Herbage mass was 2642 and 843 kg of dry matter ha–1 in the enclosures and open-access communal grazing areas, respectively. Herbaceous species diversity was higher in the enclosures than in the open-access communal grazing areas (Shannon–Wiener index: 1.8 v. 1.4, respectively). The enclosures were richer in herb species than the open-access grazing areas (13.5 v. 6.8, respectively), but values for woody species were not significantly different. Overall, we found that establishment of enclosures and the short-term protection from grazing they allow is an option for realising positive vegetation changes that support the local pastoral economy in the semiarid rangelands of eastern Ethiopia.

 

Additional keywords: communal grazing, diversity, herbaceous species, livestock, species composition, woody species.

 

 

 

 

 

Centre for Ecosystem Management, School of Natural Sciences, Edith Cowan University, Joondalup, Perth, WA 6027, Australia. Email: e.van_etten@ecu.edu.au 

 

The Rangeland Journal 35(1) 37-46 http://dx.doi.org/10.1071/RJ11088

Submitted: 6 December 2011  Accepted: 17 January 2013   Published: 18 February 2013

 

 

The majority of arid and semiarid land in the Western Australian pastoral zone has a long history of livestock grazing within an extensive network of predominantly family-held pastoral leases. A variety of different groups have purchased pastoral leases in the last five decades and, for many, making a profit from pastoralism is no longer a priority. For the central rangelands of Western Australia, these groups have included: government agencies, who have purchased some 9% of pastoral leases by area; private conservation organisations (<1% purchased); aboriginal communities and groups (~7%); and mining companies (~13%). The purchases of pastoral leases by government agencies was designed to improve the conservation status of arid-zone ecosystems, and is the first step in a process of changing land tenure to a conservation reserve. This paper summarises the extent and other characteristics of these changes in land tenure and ownership of pastoral leases, and explores the implications for land management and conservation, stemming from these changes. It demonstrates that large areas of contiguous land with no or reduced domestic stocking can now be found in many parts of these rangelands, particularly in the Coolgardie, Yalgoo and Pilbara bio-regions, with some leaseholders actively managing land for the conservation of biodiversity and restoring sites degraded through past over-grazing. In some bio-regions, such land covers considerable proportions of sub-catchments, suggesting that broad-scale conservation management and restoration objectives may be realised. It is argued that to fully realise these objectives requires effective communication and co-ordination between land managers, including sharing of ideas, view-points and resources. In particular, mining companies, now major holders of pastoral leases in Western Australia, can play an important role in contributing to and even facilitating such objectives.

 

Additional keywords: catchment management, ecosystem management, grazing management, land-use change, landscape ecology, mining, multi-functional transition, pastoralism, property rights.

 

 

 

 

Slim Saïdi ^A and Gustave Gintzburger ^{B C} 

 

^A CIRAD UMR TETIS, Baillarguet F-34398, Montpellier, France. 

^B Badia Consulting, 11 Lee-Steere Drive, Mariginiup, WA 6065, Australia. 

^C Corresponding author. Email: badiaconsulting@gmail.com 

 

The Rangeland Journal 35(1) 47-62 http://dx.doi.org/10.1071/RJ12021

Submitted: 20 April 2012  Accepted: 20 December 2012   Published: 26 February 2013

 

Sheep and goat production is the main and sometimes only agricultural activity available to populations living on rangelands in the arid regions around the Mediterranean. Desertification threatens large areas of Mediterranean arid rangelands but remains difficult to describe, quantify and accurately locate for management purposes. A methodology is described which estimates a Spatial Rain-Use Efficiency Index (SRUEI) and its potential use to evaluate rangeland condition at a large scale. It is based on an Aboveground Net Primary Production (AGNPP) map generated from field herbage mass measurements and a rainfall spatial distribution map derived from local elevation–rainfall gradients with the whole resulting from satellite imagery processing and GIS technology. The area of the case study was in the Nâama–Mecheria region located on the High Plateau south of Oran (Algeria). It covers ~215 000 ha, receiving ~200 mm year–1 of winter and spring precipitation. The Nâama–Mecheria SRUEI-derived map clearly shows the degradation gradient declining away from the settlements. The Mecheria AGNPP 2007 map and associated grazing rings indicate that the Mecheria cooperative flocks may ingest 48–57% (Range Use Factor) of the rangeland’s seasonal plant production, which is barely compatible with sustainable rangeland use. When adding the effect of fuel wood collection by local residents and rain-fed arable cropping, the Nâama–Mecheria region is undoubtedly heading towards a slow but certain desertification of its fragile arid rangelands unless correcting measures are implemented. The SRUEI and associated results are powerful tools that allow rangeland conditions to be mapped, and which can be employed in planning and pursuing sustainable management of rangelands in such arid areas.

 

Additional keywords: GIS, grazing gradient, NDVI, PVI, Rain-Use Efficiency, rangeland, satellite imagery, spatial distribution, TSAVI, vegetation cover index.

 

 

 

 

Farzaneh Khojasteh ^{A C}, Mohammad Ali Zare Chahouki ^A, Hossein Azarnivand ^A and Zaal Kikvidze ^B 

 

^A Department of Reclamation of Arid and Mountain Regions, Faculty of Natural Resources, University of Tehran, Iran. 

^B Institute of Ecology, Ilia State University, 5, Cholokashvili str., 0162, Tbilisi, Georgia. 

^C Corresponding author. Email: fkhojasteh@ut.ac.ir 

 

The Rangeland Journal 35(1) 63-69 http://dx.doi.org/10.1071/RJ12052

Submitted: 4 August 2012  Accepted: 20 December 2012   Published: 8 February 2013

 

 

The interaction among species is one of the most important factors influencing the distribution of plants in a given habitat. Vegetation of arid rangelands often appears patchy with many herbaceous species associated with shrub species. It was hypothesised that plant interactions among different life forms together with the effect of grazing preference generate this type of spatial distribution of plant species in the semi-arid rangelands of middle Iran. Spatial patterns and associations were quantitatively analysed using Hopkins’ index and Chi-square tests to establish links between spatial relationships, plant life forms and preference by grazers on the south foothills of the Taleghan ranges, Alborz Province. Data were collected from three geographical sites with different dominant species and clumped patterns of plant spatial distributions for these species were detected. These spatial patterns were probably generated by the interplay of life form-dependent facilitative interactions among plants and the grazing pressure on preferred species rather than due to their intrinsic characters. In the study sites, grass species were significantly more frequently observed in the vicinity of nurse species than in open areas. It was also found that plant-plant interactions may change in response to changes in environmental conditions, such as soil characters and the benefits achieved by the beneficiary species from being associated with nurse species. All preferred perennial species were spatially associated with shrub species (Astragalus gossypinus Fischer and Thymus kotschyanus Boiss & Hohen), while nurse species that just physically protect the beneficiary species from grazing (e.g. A. gossypinus) did not associate with non-preferred species (e.g. Stipa barbata Desf). Instead, these non-preferred species may positively aggregate with nurse plants showing other beneficial characteristics such as nitrogen fixation and improvement of soil conditions.

 

Additional keywords: competition, facilitation, grass species, shrubs, spatial association, Taleghan.

 

 

 

 

N. A. Streeton ^{A C}, R. S. B. Greene ^A, K. Marchiori ^A,  D. J. Tongway^A and M. D. Carnegie ^B 

 

^A Fenner School of Environment and Society, Australian National University, Building 48, Linnaeus Way, Canberra, ACT 0200, Australia. 

^B Lake Cowal Foundation, PO Box 138, West Wyalong, NSW 2671, Australia. 

^C Corresponding author. Email: nick.streeton@jbaconsulting.com 

 

The Rangeland Journal 35(1) 71-83 http://dx.doi.org/10.1071/RJ12046

Submitted: 12 July 2012  Accepted: 17 January 2013   Published: 13 February 2013

 

The degradation of semiarid agricultural rangelands in Australia can be traced back to the 19th century when Europeans expanded into these areas. That environmental degradation remains today and continues to harm agricultural productivity. The rehabilitation of a strongly incised ephemeral stream, ‘Spring Creek’, in central New South Wales, as an example of what can be achieved readily by landowners, is described. The causes of environmental degradation and the main environmental factors leading to the stream erosion were identified, rehabilitation began and the behaviour of the regime for 5 years within Spring Creek and the adjacent floodplain was monitored. It was found that intrinsically unstable sub-soils and sparse ground cover due to persistent grazing by domestic livestock were the major factors leading to incision. Several physical and chemical properties were found to be the primary causes of the soil’s instability. Rehabilitation focussed on stabilising the soils alongside the stream, promoting sedimentation and re-vegetation of the stream bed, with a longer-term objective of increasing the transfer of water, sediments and nutrients between the stream and its adjacent floodplain. The measures, implemented by local landowners, included the provision of in-stream porous rock weirs and the lowering of the grazing pressure on the stream bed and adjacent floodplain. Monitoring in 2007, 2009 and 2011 indicated that sedimentation was substantially faster above weirs than where there were no weirs. The rehabilitative measures resulted in the retention of fine sediment (<0.2 mm) along the stream bed behind weirs.

 

Additional keywords: controlled grazing, in-stream weirs, semi-arid.

 

 

 

 

Massimiliano Probo ^{A D}, Alessandro Massolo ^B, Michele Lonati ^A, Derek W. Bailey ^C, Alessandra Gorlier ^A, Luca Maurino ^A and Giampiero Lombardi ^A 

 

^A University of Torino, Department of Agricultural, Forest and Food Sciences, Via Leonardo da Vinci 44, Grugliasco, 10095, TO, Italy. 

^B University of Calgary, Department of Ecosystem and Public Health, 3280 Hospital Drive, NW, Calgary, AB, Canada. 

^C New Mexico State University, Department of Animal and Range Sciences, Las Cruces, NM 88003, USA. 

^D Corresponding author. Email: massimiliano.probo@unito.it 

 

The Rangeland Journal 35(1) 85-93 http://dx.doi.org/10.1071/RJ12108

Submitted: 14 December 2012  Accepted: 6 February 2013   Published: 5 March 2013

 

Throughout the last decades, agricultural abandonment in European mountain areas has caused changes in traditional livestock management with consequences for semi-natural grassland use and vegetation. In the Western Italian Alps, continuous extensive grazing has become the simplest and the most common system for managing large cattle herds. As a result, limited grazing in many rugged locations has led to an extensive shrub-encroachment of semi-natural grasslands in the sub-alpine and alpine belts. A study was conducted to assess if the provision of mineral mix supplements (MMS): (1) increases the use of steep and shrub-encroached locations by beef cows, and (2) helps restore meso-eutrophic grassland vegetation around supplement-deployment sites. During the summer grazing season, MMS were placed within 10 steep and shrub-encroached areas in two adjacent pastures (364 and 366 ha), and 12 cows were tracked with GPS collars. For each supplement site, a paired control site was identified, and vegetation surveys were performed in the surrounding areas of both sites. Placement of MMS increased the use of areas within 12 m of supplement locations compared with corresponding control areas. Cattle use of areas within 100 m of the MMS sites was also greater than expected by chance. The use by cattle, associated with trampling, grazing and faecal deposition, reduced the cover of shrubs and oligotrophic herbaceous species and increased the average nutrient N-value and forage pastoral value of the new vegetation types established around MMS sites 2 years after their use by cattle. Strategic placement of MMS appears to be a sustainable practice to restore sub-alpine and alpine shrub-encroached grasslands. Nevertheless these results must be considered preliminary as a longer period is needed to evaluate the long-term effectiveness of this practice for the restoration of semi-natural grasslands.

 

Additional keywords: beef cows, continuous grazing, dwarf shrubs, feed blocks, GPS-tracking, sustainable restoration practice.

 

 

 

 

J. A. Mavromihalis ^A, J. Dorrough ^{A B} S. G. Clark ^C, V. Turner ^A and C. Moxham ^{A D} 

 

^A Arthur Rylah Institute for Environmental Research, Department of Sustainability and Environment, Melbourne, Vic. 3084, Australia. 

^B Natural Regeneration Australia, PO Box 9103, Wyndham, NSW 2550, Australia. 

^C Department of Primary Industries, 915 Mount Napier Road, Hamilton, Vic. 3300, Australia. 

^D Corresponding author. Email: Claire.Moxham@dse.vic.gov.au 

 

The Rangeland Journal 35(1) 95-108 http://dx.doi.org/10.1071/RJ12074

Submitted: 20 September 2012  Accepted: 22 February 2013   Published: 18 March 2013

 

Temperate perennial grasslands globally have been subject to extensive biodiversity loss. Identifying livestock grazing regimes that maintain and enhance the diversity and cover of native plant species in these ecosystems remains a key challenge. The responses of vegetation to different sheep grazing regimes were assessed over 3 years in grasslands of south-eastern Australia. An open communal experimental design was used to assess the effects of varying season and duration of exclusion of grazing by sheep, replicated at three locations. Manipulation of season and duration of exclusion of grazing led to few major changes in the cover of native perennial grasses or forbs, although seasonal variation was considerable. Exclusion of grazing in the spring did increase the likelihood of occurrence of grazing-sensitive native forb species but also lead to an increase in the cover of exotic annual species. However, cover of exotic annual species tended to decline with increasing duration of exclusion, while the abundance of native, grazing-sensitive forbs and the cover of perennial grasses increased. Small-scale richness of native perennial forb species increased with a 3-month period of exclusion of grazing, but declined with year-round exclusion of sheep. Total species richness also declined in response to year-round exclusion of sheep and rates of decline were correlated with the rate at which herbage mass accumulated. While strategic grazing did not result in major vegetation changes in the short term, it is suggested that some grazing exclusion may enhance the survival of infrequent species most sensitive to sheep grazing. Caution, however, should be taken when grazing regimes implemented benefit both desirable (native forbs) and undesirable (exotic annuals) species. Having a mosaic of flexible grazing management regimes across the landscape is likely to be beneficial for native plant diversity.

 

Additional keywords: biodiversity, conservation management, exotic species, grazing exclusion, native species, pasture, strategic grazing, temperate grassland, Themeda triandra grassland.

 

 

 

 

 

Forest Products Commission, PO Box 499, Harvey, WA 6220, Australia. Email: ben.sawyer@fpc.wa.gov.au 

 

The Rangeland Journal 35(1) 109-115 http://dx.doi.org/10.1071/RJ12088

Submitted: 30 October 2012  Accepted: 8 March 2013   Published: 18 March 2013

 

Harvesting of sandalwood (Santalum spicatum) occurs mainly from wild stands in the semi-arid and arid regions (typical annual rainfall 150–300 mm) of Western Australia. Regeneration of wild sandalwood in these regions is believed to be low since the occurrence of changes in land use associated with European settlement. This is thought to be due to factors including drought, poor seed dispersal and grazing. The objective of the study was to increase the germination and establishment of sandalwood through exploring seed response to rainfall. Additionally, the potential of soil-preparation techniques to utilise trace amounts of moisture was investigated. Two 25-ha plots were located either side of the semi-arid–arid divide. Into the plots 16 replicates of the control and 96 replicates of treatments were installed and sown with 11 200 seeds. Rainfall and other weather parameters were recorded at each site with an automated weather station. The study was replicated in 2008 and 2009. It was concluded from the study that there was a statistically significant relationship between germination and rainfall. It is proposed that the germination threshold is 264 mm per year which coincides with the long-term annual rainfall average of Kalgoorlie, Western Australia. Furthermore, a statistically significant relationship between germination and soil preparation was demonstrated. Ripping crust-forming soils before sowing and the construction of water-harvest banks had a positive effect. Information gained from these studies has led to the Western Australian State Government implementing a seeding program to increase sandalwood regeneration in the semi-arid region.

 

Additional keywords: germination, seed survival, irrigation, rangelands, seed-bed preparation.