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The Rangeland Journal Abstracts

The full text of the papers is available to members of The Australian Rangeland Society at http://www.publish.csiro.au/nid/202.htm

These abstracts are from the latest issue of The Rangeland Journal.

 

The Rangeland Journal - Vol 40 (1)  2018

Nutrient composition and in vitro methane production of sub-tropical grass species in transitional rangeland of South Africa

C. J. L. du Toit A D , W. A. van Niekerk A , H. H. Meissner B , L. J. Erasmus A and L. Morey C

A Department of Animal and Wildlife Sciences, University of Pretoria, 0002, South Africa.

B No. 3 Die Hoewes, 276 von Willich Street, Centurion, 0157, South Africa.

C ARC-Biomerty, ARC-Central Office, 1134 Park Street, Hatfield, 0087, South Africa.

D Corresponding author. Email: linde.dutoit@up.ac.za

The Rangeland Journal 40(1) 1-8 https://doi.org/10.1071/RJ17057
Submitted: 21 September 2016  Accepted: 7 January 2018   Published: 22 March 2018

Abstract

The development of greenhouse gas mitigation strategies has become an important issue globally. Enteric methane (CH4) emissions from livestock do not only contribute substantially to the environmental footprint of livestock production but it also represents a loss of energy that could be channelled towards animal growth and production. In this study 14 sub-tropical grass species typical of transitional rangeland regions of South Africa were characterised in terms of ecological status, chemical composition, in vitro total gas and CH4 production. The aim of the study was 2-fold: to identify grass species that could be selected for low enteric CH4 production; evaluate the influence of rangeland ecological status on the methanogenic potential of a rangeland. Grass samples were collected by hand, air-dried, milled and analysed for nutrient composition, in vitro organic matter digestibility (IVOMD) and in vitro gas and CH4 production. Cenchrus ciliaris and Urelytrum agropyriodes produced the highest 48-h in vitro CH4 of 17.49 and 14.05 mL/g DM digested respectively. The lowest 48-h in vitro CH4 was produced by Andropogan gayanus and Bothriochloa bladhii with 5.98 and 6.08 mL/g DM digested respectively. The evaluated grass species were overall of poor quality with low CP concentrations ranging from 2.4% for Trachypogon spicatus to 6.7% for Digitaria eriantha and IVOMD ranging from 22.5% for Andropogon gayanus to 42.2% for Urelytrum agropyriodes. Decreaser grass species presented with higher in vitro CH4 production compared with Increaser I and Increaser II grass species in the present study. The results of the study emphasise the importance of including the nutritional potential of grass species for improved livestock production when evaluating grass species for possible greenhouse gas mitigation strategies.

Additional keywords: arid rangelands, climate change, grazing ecology, nutrition.

 

Estimation of aboveground herbaceous biomass using visually ranked digital photographs

Helen R. Morgan A B , Nick Reid A and John T. Hunter A

A Ecosystem Management, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.

B Corresponding author. Email: hmorgan3@myune.edu.au; millybrook@gmail.com

The Rangeland Journal 40(1) 9-18 https://doi.org/10.1071/RJ17033
Submitted: 30 April 2017  Accepted: 23 October 2017   Published: 12 December 2017

Abstract

Methods for estimating aboveground herbaceous biomass in the field have generally involved calibrating visual estimates against clipped, dried and weighed biomass samples, requiring lengthy periods of estimation and destructive sampling in the field. Here we developed and tested a photographic estimation technique (PET) that minimises field time and provides accurate estimates of aboveground herbaceous biomass. Photographs of the biomass to be estimated taken in the field are ranked against calibration images of known biomass in the laboratory. The study was conducted in New South Wales, Australia, in grassy forest dells and grasslands at Booroolong Nature Reserve in the temperate New England Tablelands Bioregion and in semi-arid grassy shrubland on Naree Station in the arid Mulga Lands Bioregion. Photographs of quadrats containing the herbaceous biomass to be estimated were taken in successive years at both sites. Calibration and validation quadrats were also photographed, and the vegetation clipped, bagged, dried and weighed. The calibration and validation photographs were rank-ordered independently by three observers in terms of estimated dry weight, and the validation quadrats assigned a putative dry weight by reference to the known weights of the calibration images in the rank order. The accuracy of each observer’s estimates was assessed by regressing the estimated weight of each validation quadrat against the actual weight, which was withheld from the observer during the estimation procedure. Regression analysis of visually estimated weights on actual weights of validation quadrats yielded regression coefficients (R2) of 0.80–0.98 and 0.81–0.97 in the temperate-zone and arid-zone sites, respectively. PET was reliably used to visually estimate aboveground herbaceous biomass across a range of communities in two different climatic zones. The benefits of PET include reduced field time, minimisation of destructive sampling and avoidance of observer drift in estimating biomass in the field.

Additional keywords: calibrate, destructive sampling, dry weight, grassland, vegetation survey.

 

Hyperspectral database prediction of ecological characteristics for grass species of alpine grasslands

Huan Yu A F G , Bo Kong B , Guangxing Wang C , Hua Sun D and Lu Wang E

A College of Earth Sciences, Chengdu University of Technology, 610059, Chengdu, China.

B Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, 610041, Chengdu, China.

C Department of Geography and Environmental Resources, Southern Illinois University, Carbondale, IL 62901, USA.

D Research Center of Forestry Remote Sensing and Information Engineering, Central South University of Forestry and Technology, 410004, Changsha, China.

E College of Natural Resources and Environment, South China Agricultural University, 510642, Guangzhou, China.

F Key Laboratory of Geoscience Spatial Information Technology of Ministry of Land and Resources, 610059, Chengdu, China.

G Corresponding author. Email: yuhuan0622@126.com

The Rangeland Journal 40(1) 19-29 https://doi.org/10.1071/RJ17084
Submitted: 23 August 2017  Accepted: 21 November 2017   Published: 27 February 2018

Abstract

Alpine grasslands are being degraded because of human activities and associated global climate change. Mapping the spatial distributions and ecological characteristics of grass species is essential for scientific management of grasslands. However, traditional field-survey methods are costly or even impossible owing to poor accessibility. Hyperspectral remote sensing provides solutions for the purpose. This study was conducted in Shenzha County of the Qiangtang Plateau, north-western Qinghai–Tibet Plateau, to examine the potential of using hyperspectral data for identifying the grass species and predicting their ecological characteristics in the alpine grasslands dominated by Stipa purpurea with co-existing species Leontopodium nanum and Oxytropis microphylla. Hyperspectral data were collected in 106 sample quadrats and the ecological characteristics of each quadrat (number and height of plants, vegetation cover, etc.) were measured. The results of spectral data analysis and regression modelling showed the following. (i) The near- and middle-infrared region was more appropriate than the visible region for discriminating the grass species. (ii) The enhanced spectral variables had much higher correlations with the ecological characteristics than the original bands. (iii) Most of the 23 derived enhanced spectral variables were significantly correlated with the number and height of the dominant species plants within the quadrats. (iv) The vegetation cover could be accurately predicted by using the models based on the enhanced spectral variables of the field-collected hyperspectral data with the relative RMSE values <28%. (v) The ecological characteristics of the dominant species could be more accurately estimated than of co-existing species. Overall, this study suggests that the hyperspectral database method provided great potential to predict the ecological characteristics of grass species in alpine grasslands.

Additional keywords: dominant species, ecosystem, monitoring, prediction.

 

Quantifying leucaena cultivation extent on grazing land

Terrence S. Beutel A D , Debra H. Corbet A , Madonna B. Hoffmann A , Stuart R. Buck A and Marco Kienzle B C

A Department of Agriculture and Fisheries, PO Box 6014, Parkhurst, Qld 4701, Australia.

B EcoSciences Precinct, GPO Box 267, Brisbane, Qld 4001, Australia.

C Centre for Applications in Natural Resource Mathematics, School of Mathematics and Physics, University of Queensland, Australia.

D Corresponding author. Email: terry.beutel@daf.qld.gov.au

The Rangeland Journal 40(1) 31-38 https://doi.org/10.1071/RJ17085
Submitted: 23 August 2017  Accepted: 11 January 2018   Published: 19 March 2018

Abstract

Leucaena is a perennial fodder crop that can significantly improve beef production across substantial parts of the world’s grazing lands. We surveyed leucaena cultivations across 350 000 km2 of Australia’s prime leucaena-growing region, using a new approach to quantify leucaena coverage and distribution. This approach uses high resolution imagery to detect leucaena by the distinctive alley cultivation pattern that is typical in the region and in many other parts of the world. We estimated there are ~123 500 ha of leucaena in the study region. Although no prior estimate of leucaena coverage has been based on exactly the same geographic area, our data strongly suggest that recent published estimates of leucaena coverage for Queensland and Australia are substantial overestimates. In addition to providing robust estimates of total leucaena coverage, we demonstrate how the method can also contribute to other survey objectives such as comparison of actual with potential spatial distribution, and assessment of statistical sampling power. We also discuss the potential application of the new method in international contexts.

Additional keywords: Leucaena leucocephala, remote sensing, survey.

 

Response of leaf traits of common plants in alpine meadow to plateau pika disturbance

Xiao Pan Pang A and Zheng Gang Guo A B

A Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture, State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China.

B Corresponding author. Email: guozhg@lzu.edu.cn

The Rangeland Journal 40(1) 39-46 https://doi.org/10.1071/RJ17089
Submitted: 3 June 2017  Accepted: 8 November 2017   Published: 12 January 2018

Abstract

Leaf traits have been proven to reflect the adaptation of individual plants to disturbance environments in a grassland ecosystem. A field survey was conducted to investigate the effects of the disturbance intensity of plateau pika on the leaf traits of a dominant (Kobresia pygmaea) and two common plants (Elymus nutans and Anemone rivularis var. flore-minore) in an alpine meadow. This study indicated that the plateau pika disturbance enables the individuals of three plants to exhibit respective plasticity because the three plants had different leaf indices (LI) as the disturbance intensity increased. K. pygmaea, E. nutans and A. rivularis var. flore-minore had high specific leaf area (SLA), leaf dry mass content (LDMC), and leaf nitrogen content (LNC) at relatively low, moderate, and high disturbance intensities of plateau pika, respectively. K. pygmaea, E. nutans and A. rivularis var. flore-minore suffered low nutrient stress at low, moderate and high disturbance intensities due to high N : P at corresponding disturbance intensities. These results indicated that K. pygmaea, E. nutans and A. rivularis var. flore-minore grew well at relatively low, moderate, and high disturbance intensity conditions, respectively, which contributed to the improvement of alpine meadows with a higher proportion of E. nutans at a moderate disturbance intensity or the deterioration of alpine meadows with a higher proportion of A. rivularis var. flore-minore at a high disturbance intensity. Our findings suggest that leaf traits are effective tools to explain how small burrowing herbivore disturbances often lead to the improvement or deterioration of alpine meadows under different disturbance intensities.

Additional keywords: alpine meadow, disturbance intensity of plateau pika, dominant and common plants, improvement or deterioration, leaf traits.

 

Environmental factors affecting the germination and emergence of white horehound (Marrubium vulgare L.): a weed of arid-zone areas

Muhammad M. Javaid A B , Singarayer K. Florentine B D , Hafiz H. Ali A and Bhagirath S. Chauhan C

A Department of Agronomy, University College of Agriculture, University of Sargodha, 40100, Pakistan.

B Centre for Environmental Management, Faculty of Science and Technology, Federation University Australia, Mt Helen, Ballarat, PO Box 663, Vic. 3350, Australia.

C The Centre for Plant Science, Queensland Alliance for Agriculture and Food Innovation (QAAFI), The University of Queensland, Gatton, Qld 4343, Australia.

D Corresponding author. Email: s.florentine@federation.edu.au

The Rangeland Journal 40(1) 47-54 https://doi.org/10.1071/RJ17121
Submitted: 29 November 2017  Accepted: 12 February 2018   Published: 19 March 2018

Abstract

White horehound (Marrubium vulgare L.), is a troublesome weed of arid zones, particularly in cropping and grazing areas. Understanding the seed ecology of white horehound is relevant to its management. The present study investigated the effects of temperature, light, osmotic potential, salinity, pH, and seeding depth on seed germination and seedling emergence of white horehound. Seeds germinated over a wide range of temperatures, with highest germination (100%) occurring at 25/20°C in either 12-h alternating light/dark or complete darkness. Germination decreased from 92% to 10% as the osmotic potential decreased from 0 to minus 0.6 MPa and germination was completely inhibited at minus 0.8 MPa. Increasing concentration of sodium chloride (salinity) from 50 to 150 mM reduced germination from 68% to 11% but was completely inhibited at 200 mM. Germination was not limited by variation of pH in solutions of pH 5 to pH 10. Maximum germination (99%) occurred at pH 7, but slightly decreased (90%) in acidic or alkaline media. Surface located seeds were highly germinable (87%) where seedling emergence significantly declined as seeding depth increased from 0.5 to 3 cm. Nil seedling emergence was occurred at 4 cm burial depth. Light significantly affected germination, time to 50% germination, mean germination time and germination index. Increasing osmotic and salinity stress both significantly increased the time to start germination, time to 50% germination, mean germination time, but decreased germination index. Burial depth adversely affected seedling emergence with surface located seedlings emerging earlier (4.2 days) compared with 20 days for seeds buried at 3 cm. Results suggest that effective management of white horehound should consider targeting surface located seeds in combination with tools that induce minimal soil disturbance, particularly in relatively non-saline environments.

Additional keywords: burial depth, photoperiod, salt stress, temperature.

 

Effect of GPS sample interval and paddock size on estimates of distance travelled by grazing cattle in rangeland, Australia

Sharon L. McGavin A , Greg J. Bishop-Hurley B F , Ed Charmley C , Paul L. Greenwood D and Matthew J. Callaghan E

A Formerly: CSIRO Agriculture and Food, Townsville, Qld 4814, Australia.

B CSIRO Agriculture and Food, St Lucia, Qld 4067, Australia.

C CSIRO Agriculture and Food, Townsville, Qld 4814, Australia.

D NSW Department of Primary Industries, Armidale, NSW 2351, Australia; and CSIRO Agriculture and Food, Armidale, NSW 2350, Australia.

E Ridley Agriproducts, Toowong, Qld 4066, Australia.

F Corresponding author. Email: greg.bishop-hurley@csiro.au

The Rangeland Journal 40(1) 55-64 https://doi.org/10.1071/RJ17092
Submitted: 5 September 2017  Accepted: 27 November 2017   Published: 27 February 2018

Abstract

The distance travelled by an animal, when determined by using global positioning system (GPS) coordinates, is usually calculated assuming linear movement between the recorded coordinates. When using long sample intervals, some movement may be overlooked if linear movement between each recorded position is assumed, because of the tendency of livestock to move in meandering paths. Conversely, overestimation of the true distance travelled could occur with short sample intervals because of the accumulation of extra distance due to GPS measurement error. Data from 10 experiments were used to explore the effect of paddock size and GPS sampling rate on the calculation of distance travelled by free-ranging cattle. Shortening the sample interval increased apparent distance travelled according to a power function. As paddock size increased from <1 ha to >450 ha, distance travelled increased according to a logarithmic relationship; however, other variation between experiments could have affected these results. It was concluded that selecting an optimal GPS sampling interval is critical to accurately determining the distance travelled by free-ranging cattle.

Additional keywords: animal behaviour, beef cattle, energetics of walking, Global Navigation Satellite System, GNSS, livestock, metabolisable energy, sampling rate, sample frequency.

 

Factors affecting herder adoption of winter lambing practices in the desert steppe region of Inner Mongolia, China

Yantin Yin A C , Zhen Wang A C , Xiliang Li A , Colin Langford B , Xiangjun Yun A , Huaibin Mu A and Xiangyang Hou A D

A Institute of Grassland Research, Chinese Academy of Agricultural Sciences, Huhhot, Inner Mongolia 010010, China.

B Graham Centre for Innovation, Charles Sturt University, Wagga Wagga, NSW 2800, Australia.

C Two authors contributed equally to this manuscript.

D Corresponding author. Email: houxy16@vip.126.com

The Rangeland Journal 40(1) 65-75 https://doi.org/10.1071/RJ17068
Submitted: 27 June 2017  Accepted: 17 November 2017   Published: 22 January 2018

Journal compilation © Australian Rangeland Society 2018 Open Access CC BY-NC-ND

Abstract

Although winter lambing practices (WL) have been shown to be a ‘win-win’ strategy for reducing the degradation of grasslands and improving herder livelihood in the pastoral regions of China, the adoption rate is still low. A survey was conducted to explore herders’ opinions of WL and other factors which influenced the adoption in the desert steppe region of Inner Mongolia, China. Herders who have spring lambing practices generally hold unfavourable opinions about WL. Most have only heard about WL but did not understand the detailed information of implementation or how it increases income. Herder ethnical background, distance to market and neighbours’ choices significantly affected the adoption rate. Han herders were more likely to adopt WL than Mongolian herders. Proximity to market led herders to be more market-focused and to adopt WL. Herders were more inclined to make the same choices as their neighbours. The results showed that herders were prepared to change and were carefully assessing the gains and losses of adopting WL. Results had implications for improving the adoption rate for WL and other livestock management practices in China.

Additional keywords: adoption, China, lambing time, land degradation, neighbourhood effect.

 

How do herders do well? Profitability potential of livestock grazing in Inner Mongolia, China, across ecosystem types

Ping Li A E F , Joleen C. Hadrich B F , Brian E. Robinson C , Yulu Hou D , Yating Dai A and Xiangyang Hou A E

A Institute of Grassland Research, Chinese Academy of Agricultural Science/Key Laboratory of Grassland Ecology and Restoration, Ministry of Agriculture, Hohhot, Inner Mongolia 010010, China.

B Department of Applied Economics, University of Minnesota, St. Paul, MN 55108-6040, USA.

C McGill University, Department of Geography, Montreal, QC H3A 0B9, Canada.

D Institute of Agricultural Information, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.

E Corresponding authors. Email: lipingcau@126.com; houxy16@126.com

F These authors contributed equally to the paper.

The Rangeland Journal 40(1) 77-90 https://doi.org/10.1071/RJ17100
Submitted: 5 October 2017  Accepted: 2 March 2018   Published: 22 March 2018

Abstract

Livestock production has increased in Inner Mongolia, China, despite widespread documentation of grassland degradation. To begin investigating the relationship that produces these trends, we studied farm-level decisions of herder households. We estimated economic enterprise budgets for 15 counties in Inner Mongolia across five ecosystems in 2009 and 2014 by using household survey data. Six counties decreased livestock stocking rates and had improved profit over time. The remaining counties increased their stocking rates over the period studied and profit decreased for all but one county. Livestock operators who reported negative profit over the 5 years were located across ecosystem types and reported a large number of weather shocks that affected grassland availability. Removing the opportunity cost of land and labour from the economic enterprise budgets resulted in a positive profit for all counties, which may explain why herders continue to increase stocking rates with decreased grassland availability over time.

Additional keywords: financial, grazing, semi-arid area.