Bird assemblages of a fragmented agricultural landscape and the relative importance of vegetation structure and landscape pattern
Matthew Johnson A B , Paul Reich A and Ralph Mac Nally AA Australian Centre for Biodiversity Analysis, Policy and Management, School of Biological Sciences, Monash University, Melbourne, Vic. 3800, Australia.
B Corresponding author. Email: Matthew.Johnson@sci.monash.edu.au
Wildlife Research 34(3) 185-193 https://doi.org/10.1071/WR06103
Submitted: 11 August 2006 Accepted: 22 March 2007 Published: 6 June 2007
Abstract
Many of the world’s agricultural areas have greatly reduced levels of natural vegetation. This results in highly fragmented mosaic landscapes with multiple land-use types. We examined the importance of vegetation and landscape pattern by comparing the bird assemblages of riparian zones, non-riparian forest patches, and pasture in a fragmented agricultural landscape in south-eastern Australia. Bird surveys were conducted every four weeks at 27 sites in the Goldfields region of central Victoria for one year. The landscape context (position and shape of patches) and vegetation attributes were measured for each site. We found that bird assemblages strongly differed among these landscape elements. Mean abundance was significantly greater at forested patches, and there was a three-fold reduction in species richness at pasture sites. Bird assemblage structure was influenced substantially more by vegetation than by the landscape context of sites. Our results indicate that riparian vegetation is a key element for avian diversity, even in massively altered landscapes. The restoration of riparian vegetation and its connectivity with adjacent forest types would greatly benefit bird assemblages in agricultural areas.
Acknowledgements
We thank: the many farmers and their families who allowed access to their properties; Sam Lake, Paul Bailey and two anonymous reviewers who helped improve the manuscript; Greg Horrocks who helped develop field methodology; Narelle Tunstall and Sven Ihnken who assisted with vegetation surveys. Financial support for this research was kindly provided by the Murray–Darling Basin Commission and the School of Biological Sciences, Monash University.
Andrén, H. (1994). Effects of habitat fragmentation on birds and mammals in landscapes with different proportions of suitable habitat: a review. Oikos 71, 355–366.
| Crossref | GoogleScholarGoogle Scholar |
Bentley, J. M. , and Catterall, C. P. (1997). The use of bushland, corridors, and linear remnants by birds in south eastern Queensland, Australia. Conservation Biology 11, 1173–1189.
| Crossref | GoogleScholarGoogle Scholar |
Clarke, K. R. (1993). Non-parametric multivariate analyses of changes in community structure. Australian Journal of Ecology 18, 117–143.
| Crossref | GoogleScholarGoogle Scholar |
Croonquist, M. J. , and Brooks, R. P. (1993). Effects of habitat disturbance on bird communities in riparian corridors. Journal of Soil and Water Conservation 48, 65–70.
Fischer, J. , and Lindenmayer, D. B. (2002). The conservation value of paddock trees for birds in a variegated landscape in southern New South Wales. 1. Species composition and site occupancy patterns. Biodiversity and Conservation 11, 807–832.
| Crossref | GoogleScholarGoogle Scholar |
Mac Nally, R. , and Horrocks, G. (2002). Relative influences of patch, landscape and historical factors on birds in an Australian fragmented landscape. Journal of Biogeography 29, 395–410.
| Crossref | GoogleScholarGoogle Scholar |
Naiman, R. , and Décamps, H. (1997). The ecology of interfaces: riparian zones. Annual Review of Ecology and Systematics 28, 621–658.
| Crossref | GoogleScholarGoogle Scholar |
Neave, H. , Cunningham, R. , Norton, T. , and Nix, H. (1996). Biological inventory for conservation evaluation: III. Relationships between birds, vegetation and environmental attributes in southern Australia. Forest Ecology and Management 85, 197–218.
| Crossref | GoogleScholarGoogle Scholar |
Palmer, G. C. , and Bennett, A. F. (2006). Riparian zones provide for distinct bird assemblages in forest mosaics of south-east Australia. Biological Conservation 130, 447–457.
| Crossref | GoogleScholarGoogle Scholar |
Radford, J. Q. , and Bennett, A. F. (2004). Thresholds in landscape parameters: occurrence of the white-browed treecreeper Climacteris affinis in Victoria, Australia. Biological Conservation 117, 375–391.
| Crossref | GoogleScholarGoogle Scholar |
Radford, J. Q. , and Bennett, A. F. (2005). Terrestrial avifauna of the Gippsland Plain and Strzelecki Ranges, Victoria, Australia: insights from Atlas data. Wildlife Research 32, 531–555.
| Crossref | GoogleScholarGoogle Scholar |
Radford, J. Q. , Bennett, A. F. , and Cheers, G. J. (2005). Landscape-level thresholds of habitat cover for woodland-dependent birds. Biological Conservation 124, 317–337.
| Crossref | GoogleScholarGoogle Scholar |
Rodewald, A. D. , and Abrams, M. D. (2002). Floristics and avian community structure: implications for regional changes in eastern forest composition. Forest Science 48, 267–272.
Sabo, J. L. , Sponseller, R. , Dixon, M. , Gade, K. , Harms, T. , Heffernan, J. , Jani, A. , Katz, G. , Soykan, C. , Watts, J. , and Welter, J. (2005). Riparian zones increase regional species richness by harboring different, not more, species. Ecology 86, 56–62.
| Crossref | GoogleScholarGoogle Scholar |
Saunders, D. A. (1989). Changes in the avifauna of a region, district and remnant as a result of fragmentation of native vegetation: the wheatbelt of Western Australia. A case study. Biological Conservation 50, 99–135.
| Crossref | GoogleScholarGoogle Scholar |
Scott, M. L. , Skagen, S. K. , and Merigliano, M. F. (2003). Relating geomorphic change and grazing to avian communities in riparian forests. Conservation Biology 17, 284–296.
| Crossref | GoogleScholarGoogle Scholar |
Tabacchi, E. , Correll, D. , Hauer, R. , Pinay, G. , Planty-Tabacchi, A. , and Wissmar, R. (1998). Development, maintenance and role of riparian vegetation in the river landscape. Freshwater Biology 40, 497–516.
| Crossref | GoogleScholarGoogle Scholar |
Watson, J. E. M. , Whittaker, R. J. , and Freudenberger, D. (2005). Bird community responses to habitat fragmentation: how consistent are they across landscapes? Journal of Biogeography 32, 1353–1370.
Wethered, R. , and Lawes, M. J. (2003). Matrix effects on bird assemblages in fragmented Afromontane forests in South Africa. Biological Conservation 114, 327–334.
| Crossref | GoogleScholarGoogle Scholar |
Woinarski, J. C. Z. , Brock, C. , Armstrong, M. , Hempel, C. , Cheal, D. , and Brennan, K. (2000). Bird distribution in riparian vegetation in the extensive natural landscape of Australia’s tropical savanna: a broad-scale survey and analysis of a distributional data base. Journal of Biogeography 27, 843–868.
| Crossref | GoogleScholarGoogle Scholar |
Woinarski, J. C. Z. , McCosker, J. C. , Gordon, G. , Lawrie, B. , James, C. , Augusteyn, J. , Slater, L. , and Danvers, T. (2006). Monitoring change in the vertebrate fauna of central Queensland, Australia, over a period of broad-scale vegetation clearance, 1973–2002. Wildlife Research 33, 263–274.
| Crossref | GoogleScholarGoogle Scholar |