Population Viability Analysis
I am interested in population modeling not solely to investigate the dynamics of populations but also to explore the effect of conservation management strategies on declining populations. I construct individual-based models for threatened and endangered plant species that incorporate density dependence through shading and clumping, predation of seeds by native rodents and birds, soil-stored seed banks, recruitment following fire events and spread of disease. I am particularly interested in the use of fire as a management tool to counteract the effects of threatening processes such as seed predation, disease and infrequent germination events. I have also worked on matrix model PVAs for animal populations threatened with harvest and habitat fragmentation.
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Plant with flowering spear from the Australian grass tree family Xanthorrhoeaceae. Flowering generally occurs within four years after a fire. |
Seeds of Grevillea caleyi. Adult plants produce at most 15 seeds each, around 80% of which are eaten by native rodents before entering the soil-stored seed bank. |
Relevant papers
Hovel, K.A. and H.M. Regan. Predator-prey relationships in seagrass landscapes: using an individual-based model to examine the roles of habitat fragmentation, habitat loss, and prey and predator behavior on prey population size. (In press)
Keith, D.A., M.G. Tozer, T.J. Regan and H.M. Regan. The persistence niche: what makes it and what breaks it for two fire-prone plant species from south-eastern Australia. Advances in Plant Conservation Special Issue. Australian Journal of Botany, (In press).
McCarthy, M.A., D.A. Keith, J. Tietjen, M.A. Burgman, M. Maunder, L. Master, B.W. Brook, G. Mace, H.P. Possingham, R. Medellin, S.J. Andelman, H.M. Regan, T.J. Regan, and M. Ruckleshaus. Comparing predictions of extinction risk using models and subjective judgement. Acta Oecologica, 26:67-74, 2004.
Gervais J and Regan HM. What conservation biology and natural resource management can offer population-level ecological risk assessment. In: Barnthouse LW, Munns WRM, and Sorensen MT (editors). Population-Level Ecological Risk Assessment. Pensacola, FL, USA. SETAC Press, (in press).
Regan, H.M. and T.D. Auld. Australian Shrub, Grevillea caleyi: Recovery through management of fire and predation. In H.R. Akçakaya, M.A. Burgman, O. Kindvall, C.C. Wood, P. Sjogren-Gulve, J. Hatfield, and M. McCarthy (eds.), Species Conservation and Management: Case Studies, Oxford University Press, pp. 23-35, 2004.
Pastorok, R.A., H.R. Akçakaya, H.M. Regan, S. Ferson, and S.M. Bartell. Role of ecological modeling in risk assessment. Human and Ecological Risk Assessment, 9(4):939-972, 2003.
Bartell, S.M., R.A. Pastorok, H.R. Akçakaya, H.M. Regan, S. Ferson and C. Mackay. Realism
and relevance of ecological models used in chemical risk assessment. Human and Ecological
Risk Assessment, 9(4):907-938, 2003.
Regan, H.M., H.R. Akçakaya, S. Ferson, K.V. Root, S. Carroll and L.R. Ginzburg.
Treatments of uncertainty and variability in ecological risk assessment of single-species populations. Human and Ecological Risk Assessment, 9(4):889-906, 2003.
Taylor, R.J., T.J. Regan, H.M. Regan, M.A. Burgman and K.Bonham. Impacts of plantation development, harvesting schedules and rotation lengths on the rare snail Tasmaphena lamproides in northwest Tasmania: a population viability analysis. Forest Ecology and Management 175:455-466, 2003.
Regan, H.M., T.D. Auld, D. Keith and M.A. Burgman. The effects of fire and predators on the long-term persistence of an endangered shrub Grevillea caleyi. Biological Conservation 109(1):73-83, 2003.
Regan H.M. Population Models: Individual-Based, in R.A. Pastorok, S.M. Bartell, S. Ferson, L.R. Ginzburg (eds.)
Ecological Modeling in Risk Assessment: Chemical Effects on Populations, Ecosystems and
Landscapes, Lewis Publishers, Boca Raton FL., pp. 65-82, 2002.
Akcakaya, H.R. and H.M. Regan. Population Models: Metapopulations, in R.A. Pastorok,
S.M. Bartell, S. Ferson, L.R. Ginzburg (eds.) Ecological Modeling in Risk Assessment:
Chemical Effects on Populations, Ecosystems and Landscapes, Lewis Publishers,
Boca Raton FL., pp. 83-95, 2002.
Regan, T.J., H.M. Regan, K. Bonham, R.J. Taylor, and M.A. Burgman. Modelling the impact of
timber harvesting on a rare carnivorous land snail (Tasmaphena lamproides) in
northwest Tasmania, Australia. Ecological Modelling, 139:253-264, 2001.
Bearlin, A.R., M.A. Burgman, and H.M. Regan. A Stochastic Model for Seagrass (Zostera muelleri)
in Port Phillip Bay, Victoria, Australia, Ecological Modelling, 118:131-148, 1999.