Are shrubs really a sign of declining ecosystem function? Disentangling the myths and truths of woody encroachment in Australia
David J. Eldridge A C and Santiago Soliveres B
+ Author Affiliations
- Author Affiliations
A NSW Office of Environment and Heritage, School of Biological, Earth and Environmental Sciences, University of NSW, Sydney, NSW 2052, Australia.
B Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland.
C Corresponding author. Email: d.eldridge@unsw.edu.au
Australian Journal of Botany 62(7) 594-608 https://doi.org/10.1071/BT14137
Submitted: 24 June 2014 Accepted: 21 November 2014 Published: 19 February 2015
Abstract
Since European settlement, there has been a dramatic increase in the density, cover and distribution of woody plants in former grassland and open woodland. There is a widespread belief that shrub encroachment is synonymous with declines in ecosystem functions, and often it is associated with landscape degradation or desertification. Indeed, this decline in ecosystem functioning is considered to be driven largely by the presence of the shrubs themselves. This prevailing paradigm has been the basis for an extensive program of shrub removal, based on the view that it is necessary to reinstate the original open woodland or grassland structure from which shrublands are thought to have been derived. We review existing scientific evidence, particularly focussed on eastern Australia, to question the notion that shrub encroachment leads to declines in ecosystem functions. We then summarise this scientific evidence into two conceptual models aimed at optimising landscape management to maximise the services provided by shrub-encroached areas. The first model seeks to reconcile the apparent conflicts between the patch- and landscape-level effects of shrubs. The second model identifies the ecosystem services derived from different stages of shrub encroachment. We also examined six ecosystem services provided by shrublands (biodiversity, soil C, hydrology, nutrient provision, grass growth and soil fertility) by using published and unpublished data. We demonstrated the following: (1) shrub effects on ecosystems are strongly scale-, species- and environment-dependent and, therefore, no standardised management should be applied to every case; (2) overgrazing dampens the generally positive effect of shrubs, leading to the misleading relationship between encroachment and degradation; (3) woody encroachment per se does not hinder any of the functions or services described above, rather it enhances many of them; (4) no single shrub-encroachment state (including grasslands without shrubs) will maximise all services; rather, the provision of ecosystem goods and services by shrublands requires a mixture of different states; and (5) there has been little rigorous assessment of the long-term effectiveness of removal and no evidence that this improves land condition in most cases. Our review provides the basis for an improved, scientifically based understanding and management of shrublands, so as to balance the competing goals of providing functional habitats, maintaining soil processes and sustaining pastoral livelihoods.
Additional keywords: shrublands, thickening, woodland.
References
Adema EO, Buschiazzo DE, Babinec FJ, Rucci TE, Hermida VFG (2004) Mechanical control of shrubs in a semiarid region of Argentina and its effect on soil water content and grassland productivity. Agricultural Water Management 68, 185–194.| Mechanical control of shrubs in a semiarid region of Argentina and its effect on soil water content and grassland productivity.Crossref | GoogleScholarGoogle Scholar |
Archer S (2009) Rangeland conservation and shrub encroachment: new perspectives on an old problem. In ‘Wild rangelands: conserving wildlife while maintaining livestock in semi-arid ecosystems’. (Eds J du Toit, R Kock, J Deutsch) pp. 53–97. (Wiley-Blackwell: Oxford, UK)
Archer S, Davies KW, Fulbright TE, McDaniel KC, Wilcox PB, Predick KI (2011) Brush management as a rangeland conservation strategy: a critical evaluation. In ‘Conservation benefits of rangeland practices: assessment, recommendations, and knowledge gaps’. (Ed. D Briske) pp. 105–170. (Allen Press: Lawrence, KS)
Ayres D, Melville G, Bean J, Beckers D, Ellis M, Mazzer T, Freudenberger D (2001) ‘Woody weeds, biodiversity and landscape function in western New South Wales. WEST 2000 woody weeds and biodiversity project.’ (WEST2000, Dubbo)
Báez S, Collins SL (2008) Shrub invasion decreases diversity and alters community stability in northern Chihuahuan Desert plant communities. PLoS ONE 3, e2332
| Shrub invasion decreases diversity and alters community stability in northern Chihuahuan Desert plant communities.Crossref | GoogleScholarGoogle Scholar | 18523686PubMed |
Baker DE, Miles RK, Eldershaw VJ (1992) Vegetation cover classes and soil nutrient status of the Mulga Lands of south-west Queensland. The Rangeland Journal 14, 40–48.
| Vegetation cover classes and soil nutrient status of the Mulga Lands of south-west Queensland.Crossref | GoogleScholarGoogle Scholar |
Barger NN, Archer SR, Campbell J, Huang C, Morton J, Knapp AK (2011) Woody plant proliferation in North American drylands: a synthesis of impacts on ecosystem carbon balance. Journal of Geophysical Research – Biogeosciences 116, G00K07
Beale IF (2004) Tree and shrub thickening in the Murweh Shire. Report to the Productivity Commission, Qld.
Belsky AJ (1994) Influences of trees on savanna productivity-tests of shade, nutrients, and tree-grass competition. Ecology 75, 922–932.
| Influences of trees on savanna productivity-tests of shade, nutrients, and tree-grass competition.Crossref | GoogleScholarGoogle Scholar |
Bhark EW, Small EE (2003) Association between plant canopies and the spatial patterns of infiltration in shrubland and grassland of the Chihuahuan Desert, New Mexico. Ecosystems 6, 185–196.
| Association between plant canopies and the spatial patterns of infiltration in shrubland and grassland of the Chihuahuan Desert, New Mexico.Crossref | GoogleScholarGoogle Scholar |
Blaum N, Rossmanith E, Popp A, Jeltsch F (2007) Shrub encroachment affects mammalian carnivore abundance and species richness in semiarid rangelands. Acta Oecologica 31, 86–92.
| Shrub encroachment affects mammalian carnivore abundance and species richness in semiarid rangelands.Crossref | GoogleScholarGoogle Scholar |
Bollard K, O’Feeke P, Oliver I, Shelly D (2010) ‘Baseline establishment for vegetation condition performance monitoring in the central west CMA region: autumn 2010 sampling program.’ (Central West Catchment Management Authority: Armidale, NSW)
Bowker MA, Eldridge DJ, Val J, Soliveres S (2013) Hydrology in a patterned landscape is co-engineered by soil-disturbing animals and biological crusts. Soil Biology & Biochemistry 61, 14–22.
| Hydrology in a patterned landscape is co-engineered by soil-disturbing animals and biological crusts.Crossref | GoogleScholarGoogle Scholar |
Breshears DD (2006) The grassland-forest continuum: trends in ecosystem properties for woody plant mosaics? Frontiers in Ecology and the Environment 4, 96–104.
| The grassland-forest continuum: trends in ecosystem properties for woody plant mosaics?Crossref | GoogleScholarGoogle Scholar |
Burgess DMN (1988) The economics of prescribed burning for shrub control in the semi-arid woodlands of north-west New South Wales. The Australian Rangeland Journal 10, 48–59.
| The economics of prescribed burning for shrub control in the semi-arid woodlands of north-west New South Wales.Crossref | GoogleScholarGoogle Scholar |
Burrows WH, Henry BK, Back PV, Hoffman MB, Tait JL, Anderson ER, Menke N, Danaher T, Carter JO, McKeon GM (2002) Growth and carbon stock change in eucalypt woodlands in northeast Australia: ecological and greenhouse sink implications. Global Change Biology 8, 769–784.
| Growth and carbon stock change in eucalypt woodlands in northeast Australia: ecological and greenhouse sink implications.Crossref | GoogleScholarGoogle Scholar |
Coffman JM, Bestelmeyer BT, Kelly JF, Wright TF, Schooley RL (2014) Restoration practices have positive effects on breeding bird species of concern in the Chihuahuan Desert. Restoration Ecology 22, 336–344.
| Restoration practices have positive effects on breeding bird species of concern in the Chihuahuan Desert.Crossref | GoogleScholarGoogle Scholar |
Collard SJ, Fisher AM (2010) Shrub-based plantings of woody perennial vegetation in temperate Australian agricultural landscapes: what benefits for native biodiversity? Ecological Management & Restoration 11, 31–35.
| Shrub-based plantings of woody perennial vegetation in temperate Australian agricultural landscapes: what benefits for native biodiversity?Crossref | GoogleScholarGoogle Scholar |
Daly RL, Hodgkinson KC (1996) Relationships between grass, shrub and tree cover on four landforms of semi-arid eastern Australia, and prospects for change by burning. The Rangeland Journal 18, 104–117.
| Relationships between grass, shrub and tree cover on four landforms of semi-arid eastern Australia, and prospects for change by burning.Crossref | GoogleScholarGoogle Scholar |
Daryanto S, Eldridge DJ (2010) Plant and soil surface responses to a combination of shrub removal and grazing in a shrub-encroached woodland. Journal of Environmental Management 91, 2639–2648.
| Plant and soil surface responses to a combination of shrub removal and grazing in a shrub-encroached woodland.Crossref | GoogleScholarGoogle Scholar | 20696514PubMed |
Daryanto S, Eldridge DJ (2012) Shrub hummocks as foci for small animal disturbances in an encroached shrubland. Journal of Arid Environments 80, 35–39.
| Shrub hummocks as foci for small animal disturbances in an encroached shrubland.Crossref | GoogleScholarGoogle Scholar |
Daryanto S, Eldridge DJ, Koen TB (2012) Soil nutrients under shrub hummocks and debris mounds two decades after ploughing. Plant and Soil 351, 405–419.
| Soil nutrients under shrub hummocks and debris mounds two decades after ploughing.Crossref | GoogleScholarGoogle Scholar |
Daryanto S, Eldridge DJ, Throop HL (2013a) Managing semi-arid woodlands for carbon storage: grazing and shrub effects on above- and belowground carbon. Agriculture, Ecosystems & Environment 169, 1–11.
| Managing semi-arid woodlands for carbon storage: grazing and shrub effects on above- and belowground carbon.Crossref | GoogleScholarGoogle Scholar |
Daryanto S, Eldridge DJ, Wang LX (2013b) Spatial patterns of infiltration vary with disturbance in a shrub-encroached woodland. Geomorphology 194, 57–64.
| Spatial patterns of infiltration vary with disturbance in a shrub-encroached woodland.Crossref | GoogleScholarGoogle Scholar |
Daryanto S, Eldridge DJ, Wang LX (2013c) Ploughing and grazing alter the spatial patterning of surface soils in a shrub-encroached woodland. Geoderma 200–201, 67–76.
| Ploughing and grazing alter the spatial patterning of surface soils in a shrub-encroached woodland.Crossref | GoogleScholarGoogle Scholar |
Dawson NM, Boyland DE (1974) ‘Western arid region land use survey. Part 1. Technical bulletin no. 12.’ (Division of Land Utilization, Queensland Department of Primary Industry: Brisbane, Qld)
de Graaff M-A, Throop H, Verburg PJ, Arnone J,, Campos X (2014) A synthesis of climate and vegetation cover effects on biogeochemical cycling in shrub-dominated drylands. Ecosystems 17, 931–945.
| A synthesis of climate and vegetation cover effects on biogeochemical cycling in shrub-dominated drylands.Crossref | GoogleScholarGoogle Scholar |
de Snoo GR, Herzon I, Staats H, Burton RJF, Schindler S, van Dijk J, Lokhorst AM, Bullock JM, Lobley M, Wrbka T, Schwarz G, Musters CJM (2013) Toward effective nature conservation on farmland: making farmers matter. Conservation Letters 6, 66–72.
| Toward effective nature conservation on farmland: making farmers matter.Crossref | GoogleScholarGoogle Scholar |
Doerr VAJ, Doerr ED, McIntyre S, Stol J, Davies M, Drew A, Warren G, Moore D, Howling G (2009) Managing invasive native scrublands for improved biodivserity outcomes in agricultural landscapes. Final scientific report, June 2009. CSIRO, Canberra.
Dreber N, Kong TM, Kellner K, Harmse C, van Eeden A, Ocampo-Melgar A (2014) Towards improved decision-making in degraded drylands of Southern Africa: an indicator based assessment for integrated evaluation of restoration and management actions in the Kalahari rangelands. GRF Davos Planet@Risk 2, March 2014.
Dwyer JM, Fensham RJ, Butler DW, Buckley YM (2009) Carbon for conservation: assessing the potential for win-win investment in an extensive Australian regrowth ecosystem. Agriculture, Ecosystems & Environment 134, 1–7.
| Carbon for conservation: assessing the potential for win-win investment in an extensive Australian regrowth ecosystem.Crossref | GoogleScholarGoogle Scholar |
Eldridge DJ (2011) The resource coupling role of animal foraging pits in semi-arid woodlands. Ecohydrology 4, 623–630.
| The resource coupling role of animal foraging pits in semi-arid woodlands.Crossref | GoogleScholarGoogle Scholar |
Eldridge DJ, Koen TB (2003) Detecting environmental change in eastern Australia: rangeland health in the semi-arid woodlands. The Science of the Total Environment 310, 211–219.
| Detecting environmental change in eastern Australia: rangeland health in the semi-arid woodlands.Crossref | GoogleScholarGoogle Scholar | 12812745PubMed |
Eldridge DJ, Wilson BR, Oliver I (2003) ‘Regrowth and soil erosion in the semi-arid woodlands of New South Wales.’ (NSW Department of Land and Water Conservation: Sydney)
Eldridge DJ, Whitford WG, Duval BD (2009) Animal disturbances promote shrub maintenance in a desertified grassland. Journal of Ecology 97, 1302–1310.
| Animal disturbances promote shrub maintenance in a desertified grassland.Crossref | GoogleScholarGoogle Scholar |
Eldridge DJ, Bowker MA, Maestre FT, Roger E, Reynolds JF, Whitford WG (2011) Impacts of shrub encroachment on ecosystem structure and functioning: towards a global synthesis. Ecology Letters 14, 709–722.
| Impacts of shrub encroachment on ecosystem structure and functioning: towards a global synthesis.Crossref | GoogleScholarGoogle Scholar | 21592276PubMed |
Eldridge DJ, Maestre FT, Moro S, Bowker MA (2012) A global database of woody encroachment effects on ecosystem structure and functioning. Ecology 93, 2499
| A global database of woody encroachment effects on ecosystem structure and functioning.Crossref | GoogleScholarGoogle Scholar |
Eldridge DJ, Soliveres S, Bowker MA, Val J (2013) Grazing dampens the positive effects of shrub encroachment on ecosystem functions in a semi-arid woodland. Journal of Applied Ecology 50, 1028–1038.
| Grazing dampens the positive effects of shrub encroachment on ecosystem functions in a semi-arid woodland.Crossref | GoogleScholarGoogle Scholar |
Eldridge DJ, Wang L, Ruiz-Colmenero M (2014) Shrub encroachment alters the spatial patterns of infiltration. Ecohydrology,
| Shrub encroachment alters the spatial patterns of infiltration.Crossref | GoogleScholarGoogle Scholar |
Farquharson B, Kelly J, Welsh P, Mazurd K, Bennett J (2010) Policy responses to invasive native species: issues of social and private benefits and costs. In ‘53rd annual conference of the Australian Agricultural and Resource Economics Society Inc., Cairns, 10–13 February 2010’.
Fensham RJ (2008) A protocol for assessing applications to selectively clear vegetation in Queensland, Australia. Land Use Policy 25, 249–258.
| A protocol for assessing applications to selectively clear vegetation in Queensland, Australia.Crossref | GoogleScholarGoogle Scholar |
Fensham RJ, Fairfax RJ, Archer SR (2005) Rainfall, land use and woody vegetation cover change in semi-arid Australian savanna. Journal of Ecology 93, 596–606.
| Rainfall, land use and woody vegetation cover change in semi-arid Australian savanna.Crossref | GoogleScholarGoogle Scholar |
Fensham RJ, Dwyer JM, Eyre TJ, Fairfax RJ, Wang J (2012) The effect of clearing on plant composition in mulga (Acacia aneura) dry forest, Australia. Austral Ecology 37, 183–192.
| The effect of clearing on plant composition in mulga (Acacia aneura) dry forest, Australia.Crossref | GoogleScholarGoogle Scholar |
Fisher DO (2000) Effects of vegetation structure, food and shelter on the home range and habitat use of an endangered wallaby. Journal of Applied Ecology 37, 660–671.
| Effects of vegetation structure, food and shelter on the home range and habitat use of an endangered wallaby.Crossref | GoogleScholarGoogle Scholar |
Gardiner DB, Tupper GJ, Dundeon GS (1998) A quantitative appraisal of woody shrub encroachment in western New South Wales. The Rangeland Journal 20, 26–40.
| A quantitative appraisal of woody shrub encroachment in western New South Wales.Crossref | GoogleScholarGoogle Scholar |
Good MK, Price JN, Clarke PC, Reid N (2011) Densely regenerating coolibah (Eucalyptus coolabah) woodlands are more species-rich than surrounding derived grasslands in floodplains of eastern Australia. Australian Journal of Botany 59, 468–479.
| Densely regenerating coolibah (Eucalyptus coolabah) woodlands are more species-rich than surrounding derived grasslands in floodplains of eastern Australia.Crossref | GoogleScholarGoogle Scholar |
Goslee SC, Havstad KM, Peters DPC, Rango A, Schlesinger WH (2003) High-resolution images reveal rate and pattern of shrub encroachment over six decades in New Mexico, USA. Journal of Arid Environments 54, 755–767.
| High-resolution images reveal rate and pattern of shrub encroachment over six decades in New Mexico, USA.Crossref | GoogleScholarGoogle Scholar |
Green D, Hart D, Prior J (2000) ‘Rangeland study site manual part 1: site selection and field measurement procedures.’ (Department of Land and Water Conservation: Condobolin, NSW)
Gutierrez J, Hernandez II (1996) Runoff and interrill erosion as affected by grass cover in a semi-arid rangeland of northern Mexico. Journal of Arid Environments 34, 287–295.
| Runoff and interrill erosion as affected by grass cover in a semi-arid rangeland of northern Mexico.Crossref | GoogleScholarGoogle Scholar |
Hacker R (2009) Monitoring and evaluating the WEST 2000 Plus ground cover enterprise based conservation projects. Final report to the Western Catchment Management Authority for Project No. 06/01. NSW Department of Primary Industries, Dubbo, NSW.
Harland R (Ed.) (1993) ‘Managing for woody weed control in Western NSW.’ (Woody Weeds Task Force: Dubbo, NSW)
Harris RB (2010) Rangeland degradation on the Qinghai–Tibetan plateau: a review of the evidence of its magnitude and causes. Journal of Arid Environments 74, 1–12.
| Rangeland degradation on the Qinghai–Tibetan plateau: a review of the evidence of its magnitude and causes.Crossref | GoogleScholarGoogle Scholar |
Hassall & Associates, Briggs S, Norman P (2006) ‘Documenting the science behind the invasive native scrub tool.’ (Central West Catchment Management Authority: Dubbo, NSW)
Hilker T, Natsagdorj E, Waring RH, Lyapustin A, Wang Y (2014) Satellite observed widespread decline in Mongolian grasslands largely due to overgrazing. Global Change Biology 20, 418–428.
| Satellite observed widespread decline in Mongolian grasslands largely due to overgrazing.Crossref | GoogleScholarGoogle Scholar | 23966315PubMed |
Hodgkinson KC (1991) Shrub recruitment response to intensity and season of fire in a semiarid woodland. Journal of Applied Ecology 28, 60–70.
| Shrub recruitment response to intensity and season of fire in a semiarid woodland.Crossref | GoogleScholarGoogle Scholar |
House JI, Archer S, Breshears DD, Scholes RJ (2003) Conundrums in mixed woody–herbaceous plant systems. Journal of Biogeography 30, 1763–1777.
| Conundrums in mixed woody–herbaceous plant systems.Crossref | GoogleScholarGoogle Scholar |
Howard KSC, Eldridge DJ, Soliveres S (2012) Positive effects of shrubs on plant species diversity do not change along a gradient in grazing pressure in an arid shrubland. Basic and Applied Ecology 13, 159–168.
| Positive effects of shrubs on plant species diversity do not change along a gradient in grazing pressure in an arid shrubland.Crossref | GoogleScholarGoogle Scholar |
Huenneke LF, Anderson JP, Remmenga M, Schlesinger WH (2002) Desertification alters patterns of aboveground net primary production in Chihuahuan ecosystems. Global Change Biology 8, 247–264.
| Desertification alters patterns of aboveground net primary production in Chihuahuan ecosystems.Crossref | GoogleScholarGoogle Scholar |
Hughes RF, Archer S, Asner GP, Wessman CA, McMurtry C, Nelson J (2006) Changes in aboveground primary production and carbon and nitrogen pools accompanying woody plant encroachment in a temperate savanna. Global Change Biology 12, 1733–1747.
| Changes in aboveground primary production and carbon and nitrogen pools accompanying woody plant encroachment in a temperate savanna.Crossref | GoogleScholarGoogle Scholar |
Iannone BV, Zellber ML, Wise DH (2014) Modelling the impacts of life-history traits, canopy gaps, and establishment location on woodland shrub invasions. Ecological Applications 24, 467–483.
| Modelling the impacts of life-history traits, canopy gaps, and establishment location on woodland shrub invasions.Crossref | GoogleScholarGoogle Scholar | 24834734PubMed |
Inter-Departmental Committee (1969) Report of the Inter-departmental Committee on Scrub and Timber Growth in the Cobar–Byrock District and Other Areas of the Western Division of New South Wales. Government Printer, Sydney.
Jackson RB, Banner JL, Jobbagy EG, Pockman WT, Wall DH (2002) Ecosystem carbon loss with woody plant invasion of grasslands. Nature 418, 623–626.
| Ecosystem carbon loss with woody plant invasion of grasslands.Crossref | GoogleScholarGoogle Scholar | 12167857PubMed |
Jankju M (2013) Role of nurse shrubs in restoration of an arid rangeland: effects of microclimate on grass establishment. Journal of Arid Environments 89, 103–109.
| Role of nurse shrubs in restoration of an arid rangeland: effects of microclimate on grass establishment.Crossref | GoogleScholarGoogle Scholar |
Kéfi S, Rietkerk M, Alados CL, Pueyo Y, Papanastasis VP, ElAich A, de Ruiter PC (2007) Spatial vegetation patterns and imminent desertification in Mediterranean arid ecosystems. Nature 449, 213–217.
| Spatial vegetation patterns and imminent desertification in Mediterranean arid ecosystems.Crossref | GoogleScholarGoogle Scholar | 17851524PubMed |
Kerle A (2009) Managing rangeland vegetation with fire: a literature review and recommendations. Report prepared for the Western Catchment Management Authority, Dubbo, NSW.
Knapp AK, Briggs JM, Collins SC, Archer SR, Bret-Harte MS, Ewers BE, Peters DP, Young DR, Shaver GR, Pendall E, Cleary MB (2008) Shrub encroachment in North American grasslands: shifts in growth form dominance rapidly alters control of ecosystem carbon inputs. Global Change Biology 14, 615–623.
| Shrub encroachment in North American grasslands: shifts in growth form dominance rapidly alters control of ecosystem carbon inputs.Crossref | GoogleScholarGoogle Scholar |
Lee AC, Conner JR, Mjelde JW, Richardson JW, Stuth JW (2001) Regional cost share necessary for rancher participation in brush control. Journal of Agricultural and Resource Economics 26, 478–490.
Levin SA (1992) The problem of pattern and scale in ecology. Ecology 73, 1943–1983.
Liancourt P, Callaway RM, Michalet R (2005) Stress tolerance and competitive-response ability determine the outcome of biotic interactions. Ecology 86, 1611–1618.
| Stress tolerance and competitive-response ability determine the outcome of biotic interactions.Crossref | GoogleScholarGoogle Scholar |
Liao JD, Boutton TW (2008) Soil microbial biomass response to woody plant invasion of grassland. Soil Biology & Biochemistry 40, 1207–1216.
| Soil microbial biomass response to woody plant invasion of grassland.Crossref | GoogleScholarGoogle Scholar |
Ludwig J, Tongway DJ (1995) Desertification in Australia: an eye to grass roots and landscapes. Environmental Monitoring and Assessment 37, 231–237.
| Desertification in Australia: an eye to grass roots and landscapes.Crossref | GoogleScholarGoogle Scholar | 24197851PubMed |
Lunt ID (2005) ‘Effects of stock grazing on biodiversity values in temperate native grasslands and grassy woodlands in SE Australia: a literature review.’ (Environment ACT: Canberra)
Lunt ID, Eldridge DJ, Morgan JW, Witt GB (2007) A framework to predict the effects of livestock grazing and grazing exclusion on conservation values in natural ecosystems in Australia. Australian Journal of Botany 55, 401–415.
| A framework to predict the effects of livestock grazing and grazing exclusion on conservation values in natural ecosystems in Australia.Crossref | GoogleScholarGoogle Scholar |
Lunt ID, Winsemius LM, McDonald SP, Morgan JW, Dehaan RL (2010) How widespread is woody plant encroachment in temperate Australia? Changes in woody vegetation cover in lowland woodland and coastal ecosystems in Victoria from 1989 to 2005. Journal of Biogeography 37, 722–732.
| How widespread is woody plant encroachment in temperate Australia? Changes in woody vegetation cover in lowland woodland and coastal ecosystems in Victoria from 1989 to 2005.Crossref | GoogleScholarGoogle Scholar |
Maestre FT, Cortina J (2004) Do positive interactions increase with abiotic stress? A test from a semi-arid steppe. Proceedings of the Royal Society of London. Series B. Biological Sciences 271, S331–S333.
| Do positive interactions increase with abiotic stress? A test from a semi-arid steppe.Crossref | GoogleScholarGoogle Scholar |
Maestre FT, Bowker MA, Puche MD, Belén Hinojosa M, Martínez I, García-Palacios P, Castillo AP, Soliveres S, Luzuriaga AL, Sánchez AM, Carreira JA, Gallardo A, Escudero A (2009) Shrub encroachment can reverse desertification in semi-arid Mediterranean grasslands. Ecology Letters 12, 930–941.
| Shrub encroachment can reverse desertification in semi-arid Mediterranean grasslands.Crossref | GoogleScholarGoogle Scholar | 19638041PubMed |
Maestre FT, Quero JL, Maestre FT, Quero JL, Gotelli NJ, Escudero A, Ochoa V, Delgado-Baquerizo M, García-Gómez M, Bowker MA, Soliveres S, Escolar C, García-Palacios P, Berdugo M, Valencia E, Gozalo B, Gallardo A, Aguilera L, Arredondo T, Blones J, Boeken B, Bran D, Conceição AA, Cabrera O, Chaieb M, Derak M, Eldridge DJ, Espinosa CI, Florentino A, Gaitán J, Gatica MG, Ghiloufi W, Gómez-González S, Gutiérrez JR, Hernández RM, Huang X, Huber-Sannwald E, Jankju M, Miriti M, Monerris J, Mau RL, Morici E, Naseri K, Ospina A, Polo V, Prina A, Pucheta E, Ramírez-Collantes DA, Romão R, Tighe M, Torres-Díaz C, Val J, Veiga JP, Wang D, Zaady E (2012) Plant species richness and ecosystem multifunctionality in global drylands. Science 335, 214–218.
McHenry MT, Wilson BR, Lemon JM, Donelly DE, Growns IG (2006) Soil and vegetation response to thinning white cypress pine (Callitris glaucophylla) on the north western slopes of New South Wales, Australia. Plant and Soil 285, 245–255.
| Soil and vegetation response to thinning white cypress pine (Callitris glaucophylla) on the north western slopes of New South Wales, Australia.Crossref | GoogleScholarGoogle Scholar |
Milchunas DG, Sala OE, Lauenroth WK (1988) A generalized-model of the effects of grazing by large herbivores on grassland community structure. American Naturalist 132, 87–106.
| A generalized-model of the effects of grazing by large herbivores on grassland community structure.Crossref | GoogleScholarGoogle Scholar |
Millennium Ecosystem Assessment (2005) ‘Ecosystems and human well-being: desertification synthesis.’ (World Resources Institute: Washington, DC)
Muñoz-Robles C, Reid N, Tighe M, Briggs SV, Wilson B (2011a) Soil hydrological and erosional responses in areas of woody encroachment, pasture and woodland in semi-arid Australia. Journal of Arid Environments 75, 936–945.
| Soil hydrological and erosional responses in areas of woody encroachment, pasture and woodland in semi-arid Australia.Crossref | GoogleScholarGoogle Scholar |
Muñoz-Robles C, Reid N, Tighe M, Briggs SV, Wilson B (2011b) Soil hydrological and erosional responses in patches and inter-patches in vegetation states in semi-arid Australia. Geoderma 160, 524–534.
| Soil hydrological and erosional responses in patches and inter-patches in vegetation states in semi-arid Australia.Crossref | GoogleScholarGoogle Scholar |
Musters CJM, Kruk M, de Graaf HJ, ter Keurs WJ (2001) Breeding birds as a farm product. Conservation Biology 15, 363–369.
| Breeding birds as a farm product.Crossref | GoogleScholarGoogle Scholar |
New South Wales Government (2013) ‘Clearing of invasive native species. Order made under Clause 38 of the Native Vegetation Regulation 2013.’ (Office of Environment and Heritage NSW: Sydney)
Niering WA, Lowe CH, Whittaker R, Whittaker RH (1963) Saguaro: a population in relation to environment. Science 142, 15–23.
| Saguaro: a population in relation to environment.Crossref | GoogleScholarGoogle Scholar | 17812501PubMed |
Noble JC (1997) ‘The delicate and noxious shrub.’ (CSIRO: Canberra)
Noble JC, Müller WJ, MacLeod ND, Bodulovic Z, Jones P, Wood JT (2005) Integrated shrub management in semi-arid woodlands of eastern Australia: ground and aerial application of defoliant to shrubs regenerating after disturbance. The Rangeland Journal 27, 117–134.
| Integrated shrub management in semi-arid woodlands of eastern Australia: ground and aerial application of defoliant to shrubs regenerating after disturbance.Crossref | GoogleScholarGoogle Scholar |
Okin GS, Gillette DA (2001) Distribution of vegetation in wind-dominated landscapes: implications for wind erosion modeling and landscape processes. Journal of Geophysical Research. D. Atmospheres 106, 9673–9683.
| Distribution of vegetation in wind-dominated landscapes: implications for wind erosion modeling and landscape processes.Crossref | GoogleScholarGoogle Scholar |
Okin GS, D’Odorico P, Archer SR (2009) Impact of feedbacks on Chihuahuan desert grasslands: transience and metastability. Journal of Geophysical Research-Biogeosciences 114,
Pauling L (1995) ‘Linus Pauling in his own words: selections from his writings, speeches, and interviews.’ (Ed. B Marinacci) (Touchstone: New York)
Prider JN, Facelli JM (2004) Interactive effects of drought and shade on three arid zone chenopod shrubs with contrasting distributions in relation to tree canopies. Functional Ecology 18, 67–76.
| Interactive effects of drought and shade on three arid zone chenopod shrubs with contrasting distributions in relation to tree canopies.Crossref | GoogleScholarGoogle Scholar |
Quinn GP, Keogh MJ (2002) ‘Experimental Design and Data Analysis for Biologists’ (Cambridge University Press: Cambridge, UK)
Reich PB, Peterson DW, Wedin DA, Wrage K (2001) Fire and vegetation effects on productivity and nitrogen cycling across a forest–grassland continuum. Ecology 82, 1703–1719.
Reynolds JF, Acock B (1997) Modularity and genericness in plant and ecosystem models. Ecological Modelling 94, 7–16.
| Modularity and genericness in plant and ecosystem models.Crossref | GoogleScholarGoogle Scholar |
Riginos C, Grace JB, Augustine DJ, Young TP (2009) Local versus landscape-scale effects of savanna trees on grasses. Journal of Ecology 97, 1337–1345.
| Local versus landscape-scale effects of savanna trees on grasses.Crossref | GoogleScholarGoogle Scholar |
Robson AD (1995) The effect of grazing exclusion and blade-ploughing on semi-arid woodland vegetation in north-western New South Wales over 30 months. Rangeland Journal 17, 111–127.
| The effect of grazing exclusion and blade-ploughing on semi-arid woodland vegetation in north-western New South Wales over 30 months.Crossref | GoogleScholarGoogle Scholar |
Rodríguez-Echeverría S, Pérez Fernández MA (2003) Soil fertility and herbaceous facilitation mediated by Retama sphaerocarpa. Journal of Vegetation Science 14, 807–814.
| Soil fertility and herbaceous facilitation mediated by Retama sphaerocarpa.Crossref | GoogleScholarGoogle Scholar |
Scanlan JC (1986) Influence of the tree basal area on pasture yield and composition. In ‘Rangelands: a resource under siege. Proceedings of the second international rangeland congress’. (Eds PJ Joss, PW Lynch, OB Williams) pp. 66–67. (Cambridge University Press: London)
Schlesinger WH, Reynolds JF, Cunningham GL, Huenneke LF, Jarrell WM, Virginia RA, Whitford WG (1990) Biological feedbacks in global desertification. Science 247, 1043–1048.
| Biological feedbacks in global desertification.Crossref | GoogleScholarGoogle Scholar | 17800060PubMed |
Scholte PT (1989) Vegetation-soil relations in an area with sealed chromic luvisols. Arid Soil Research and Rehabilitation 3, 337–348.
| Vegetation-soil relations in an area with sealed chromic luvisols.Crossref | GoogleScholarGoogle Scholar |
Segoli M, Ungar ED, Shachak M (2008) Shrubs enhance resilience of a semi-arid ecosystem by engineering and regrowth. Ecohydrology 1, 330–339.
| Shrubs enhance resilience of a semi-arid ecosystem by engineering and regrowth.Crossref | GoogleScholarGoogle Scholar |
Silcock JL, Fensham RJ (2013) Arid vegetation in disequilibrium with livestock grazing: evidence from long-term exclosures. Austral Ecology 38, 57–65.
| Arid vegetation in disequilibrium with livestock grazing: evidence from long-term exclosures.Crossref | GoogleScholarGoogle Scholar |
Silcock JL, Piddocke TP, Fensham RJ (2013) Illuminating the dawn of pastoralism: evaluating the record of European explorers to inform landscape change. Biological Conservation 159, 321–331.
| Illuminating the dawn of pastoralism: evaluating the record of European explorers to inform landscape change.Crossref | GoogleScholarGoogle Scholar |
Sirami C, Seymour C, Midgley G, Barnard P (2009) The impact of shrub encroachment on savanna bird diversity from local to regional scale. Diversity & Distributions 15, 948–957.
| The impact of shrub encroachment on savanna bird diversity from local to regional scale.Crossref | GoogleScholarGoogle Scholar |
Sitters J, Edwards PJ, Venterink HO (2013) Increases of soil C, N, and P pools along an acacia tree density gradient and their effects on trees and grasses. Ecosystems 16, 347–357.
| Increases of soil C, N, and P pools along an acacia tree density gradient and their effects on trees and grasses.Crossref | GoogleScholarGoogle Scholar |
Smallbone LT, Matthews A, Lunt ID (2014) Regrowth provides complementary habitat for woodland birds of conservation concern in a regenerating agricultural landscape. Landscape and Urban Planning 124, 43–52.
| Regrowth provides complementary habitat for woodland birds of conservation concern in a regenerating agricultural landscape.Crossref | GoogleScholarGoogle Scholar |
Smit C, Vandenberghe C, den Ouden J, Mueller-Schaerer H (2007) Nurse plants, tree saplings and grazing pressure: changes in facilitation along a biotic environmental gradient. Oecologia 152, 265–273.
| Nurse plants, tree saplings and grazing pressure: changes in facilitation along a biotic environmental gradient.Crossref | GoogleScholarGoogle Scholar | 17279351PubMed |
Smith AT, Foggin JM (1999) The plateau pika (Ochotona curzoniae) is a keystone species for biodiversity on the Tibetan plateau. Animal Conservation 2, 235–240.
| The plateau pika (Ochotona curzoniae) is a keystone species for biodiversity on the Tibetan plateau.Crossref | GoogleScholarGoogle Scholar |
Snowdon P, Ryan PJR (2005) Review of C : N ratios in vegetation, litter and soil under Australian native forests and plantations. National Carbon Accounting System Technical Report No. 45. Australian Greenhouse Office, Canberra.
Soliveres S, Eldridge DJ (2014) Do changes in grazing pressure and the degree of shrub encroachment alter the effects of individual shrubs on understorey plant communities and soil function? Functional Ecology 28, 530–537.
| Do changes in grazing pressure and the degree of shrub encroachment alter the effects of individual shrubs on understorey plant communities and soil function?Crossref | GoogleScholarGoogle Scholar |
Soliveres S, Eldridge DJ, Maestre FT, Bowker MA, Tighe M, Escudero A (2011) Microhabitat amelioration and reduced competition among understorey plants as drivers of facilitation across environmental gradients: towards a unifying framework. Perspectives in Plant Ecology, Evolution and Systematics 13, 247–258.
| Microhabitat amelioration and reduced competition among understorey plants as drivers of facilitation across environmental gradients: towards a unifying framework.Crossref | GoogleScholarGoogle Scholar |
Soliveres S, Eldridge DJ, Hemmings F, Maestre FT (2012) Nurse plant effects on plant species richness in drylands: the role of grazing, rainfall and species specificity. Perspectives in Plant Ecology, Evolution and Systematics 14, 402–410.
| Nurse plant effects on plant species richness in drylands: the role of grazing, rainfall and species specificity.Crossref | GoogleScholarGoogle Scholar |
Soliveres S, Maestre FT, Eldridge DJ, Delgado-Baquerizo M, Quero JL, Bowker MA, Gallardo A (2014) Plant diversity and ecosystem multifunctionality peak at intermediate levels of woody cover in global drylands. Global Ecology and Biogeography 23, 1408–1416.
| Plant diversity and ecosystem multifunctionality peak at intermediate levels of woody cover in global drylands.Crossref | GoogleScholarGoogle Scholar |
Solomon TB, Snyman HA, Smit GN (2007) Cattle-rangeland management practices and perceptions of pastoralists towards rangeland degradation in the Borana zone of southern Ethiopia. Journal of Environmental Management 82, 481–494.
| Cattle-rangeland management practices and perceptions of pastoralists towards rangeland degradation in the Borana zone of southern Ethiopia.Crossref | GoogleScholarGoogle Scholar | 16616986PubMed |
Stafford Smith M, Foran B (1992) An approach to assessing the economic risk of different drought management tactics on a South Australian pastoral sheep station. Agricultural Systems 39, 83–105.
| An approach to assessing the economic risk of different drought management tactics on a South Australian pastoral sheep station.Crossref | GoogleScholarGoogle Scholar |
Teague WR, Borchard R, Ansley J, Pinchak B, Cox J, Foy JK, McGrann J (1997) Sustainable management strategies for mesquite rangeland: the Waggoner Kite project. Rangelands 19, 4–9.
Tewksbury JJ, Lloyd JD (2001) Positive interactions under nurse-plants: spatial scale, stress gradients and benefactor size. Oecologia 127, 425–434.
| Positive interactions under nurse-plants: spatial scale, stress gradients and benefactor size.Crossref | GoogleScholarGoogle Scholar |
Thompson WA, Eldridge DJ (2005) Plant cover and composition in relation to density of Callitris glaucophylla (white cypress pine) along a rainfall gradient in eastern Australia. Australian Journal of Botany 53, 545–554.
| Plant cover and composition in relation to density of Callitris glaucophylla (white cypress pine) along a rainfall gradient in eastern Australia.Crossref | GoogleScholarGoogle Scholar |
Throop HL, Archer SR (2007) Interrelationships among shrub encroachment, land management, and litter decomposition in a semidesert grassland. Ecological Applications 17, 1809–1823.
| Interrelationships among shrub encroachment, land management, and litter decomposition in a semidesert grassland.Crossref | GoogleScholarGoogle Scholar | 17913142PubMed |
Tielbörger K, Kadmon R (2000) Temporal environmental variation tips the balance between facilitation and interference in desert plants. Ecology 81, 1544–1553.
| Temporal environmental variation tips the balance between facilitation and interference in desert plants.Crossref | GoogleScholarGoogle Scholar |
Tighe M, Reid N, Wilson B, Briggs SV (2009) Invasive native scrub and soil condition in semi-arid south-eastern Australia. Agriculture, Ecosystems & Environment 132, 212–222.
| Invasive native scrub and soil condition in semi-arid south-eastern Australia.Crossref | GoogleScholarGoogle Scholar |
Tothill JC (1971) A review of fire in the management of native pasture with particular reference to north-eastern Australia. Tropical Grasslands 5, 1–10.
Treydte AC, Heitkoenig IMA, Ludwig F (2009) Modelling ungulate dependence on higher quality forage under large trees in African savannahs. Basic and Applied Ecology 10, 161–169.
| Modelling ungulate dependence on higher quality forage under large trees in African savannahs.Crossref | GoogleScholarGoogle Scholar |
Treydte AC, van der Beek JGM, Perdok AA, van Wieren SE (2011) Grazing ungulates select for grasses growing beneath trees in African savannas. Mammalian Biology 76, 345–350.
| Grazing ungulates select for grasses growing beneath trees in African savannas.Crossref | GoogleScholarGoogle Scholar |
Van Auken OW (2000) Shrub invasions of North American semiarid grasslands. Annual Review of Ecology and Systematics 31, 197–215.
| Shrub invasions of North American semiarid grasslands.Crossref | GoogleScholarGoogle Scholar |
Van Auken OW (2009) Causes and consequences of woody plant encroachment into western North American grasslands. Journal of Environmental Management 90, 2931–2942.
| Causes and consequences of woody plant encroachment into western North American grasslands.Crossref | GoogleScholarGoogle Scholar | 19501450PubMed |
Vandenberghe C, Smit C, Pohl M, Buttler A, Frelechoux F (2009) Does the strength of facilitation by nurse shrubs depend on grazing resistance of tree saplings? Basic and Applied Ecology 10, 427–436.
| Does the strength of facilitation by nurse shrubs depend on grazing resistance of tree saplings?Crossref | GoogleScholarGoogle Scholar |
Warnock AD, Westbrooke ME, Florentine SK, Hurst CP (2007) Does Geijera parviflora Lindl (Rutaceae) facilitate understorey species in semi-arid Australia? The Rangeland Journal 29, 207–216.
| Does Geijera parviflora Lindl (Rutaceae) facilitate understorey species in semi-arid Australia?Crossref | GoogleScholarGoogle Scholar |
Weltzin JF, Coughenour MB (1990) Savanna tree influence on understory vegetation and soil nutrients in northwestern Kenya. Journal of Vegetation Science 1, 325–334.
| Savanna tree influence on understory vegetation and soil nutrients in northwestern Kenya.Crossref | GoogleScholarGoogle Scholar |
Whitford WG (2002) ‘Ecology of desert ecosystems.’ (Academic Press: London)
Wilcox BP, Breshears DD, Turin HJ (2003a) Hydraulic conductivity in a pinon–juniper woodland: influence of vegetation. Soil Science Society of America Journal 67, 1243–1249.
| Hydraulic conductivity in a pinon–juniper woodland: influence of vegetation.Crossref | GoogleScholarGoogle Scholar |
Wilcox BP, Breshears DD, Allen CD (2003b) Ecohydrology of a resource-conserving semiarid woodland: effects of scale and disturbance. Ecological Monographs 73, 223–239.
| Ecohydrology of a resource-conserving semiarid woodland: effects of scale and disturbance.Crossref | GoogleScholarGoogle Scholar |
Williams P, Young M (1999) ‘Costing dust: how much does wind erosion cost the people of South Australia?’ (Policy and Economic Research Unit, CSIRO Land and Water: Canberra)
Witt GB (2013) Vegetation changes through the eyes of the locals: the ‘artificial wilderness in the mulga country of south-west Queensland. The Rangeland Journal 35, 299–314.
| Vegetation changes through the eyes of the locals: the ‘artificial wilderness in the mulga country of south-west Queensland.Crossref | GoogleScholarGoogle Scholar |
Witt GB, Harrington RA, Page MJ (2009) Is ‘vegetation thickening’ occurring in Queensland’s mulga lands: a 50-year aerial photographic analysis. Australian Journal of Botany 57, 572–582.
| Is ‘vegetation thickening’ occurring in Queensland’s mulga lands: a 50-year aerial photographic analysis.Crossref | GoogleScholarGoogle Scholar |
Witt GB, Noel MV, Bird MI, Beeton RJS, Menzies NW (2011) Carbon sequestration and biodiversity restoration potential of semi-arid mulga lands of Australia interpreted from long-term grazing exclosures. Agriculture, Ecosystems & Environment 141, 108–118.
| Carbon sequestration and biodiversity restoration potential of semi-arid mulga lands of Australia interpreted from long-term grazing exclosures.Crossref | GoogleScholarGoogle Scholar |
Zarovali MP, Yiakoulaki MD, Papanastasis VP (2007) Effects of shrub encroachment on herbage production and nutritive value in semi-arid Mediterranean grasslands. Grass and Forage Science 62, 355–363.
| Effects of shrub encroachment on herbage production and nutritive value in semi-arid Mediterranean grasslands.Crossref | GoogleScholarGoogle Scholar |
Zhang YM, Zhang ZB, Liu JK (2003) Burrowing rodents as ecosystem engineers: the ecology and management of plateau zokors Myospalax fontanierii in alpine meadow ecosystems on the Tibetan Plateau. Mammal Review 33, 284–294.
| Burrowing rodents as ecosystem engineers: the ecology and management of plateau zokors Myospalax fontanierii in alpine meadow ecosystems on the Tibetan Plateau.Crossref | GoogleScholarGoogle Scholar |
