Eucalyptus camaldulensis River redgum
Gray Golden Eucalyptus Background ~800 species in Eucalyptus genus Medium sized, 30-40 m (E. camaldulensis) Introduced to California in 1850’s at Oakland/S.F. nurseries Uses: fuel, fiberboard, pulp, windbreaks, ornamentation various medicines, charcoal, a mixing agent for gasoline engines, draining waste water to eliminate malaria Firestorms Climate E. camalduldensis prefers riparian sites with permanent or seasonal water. 1917 CA drought, temps 110-120 deg. F (10 trees died out of 4,461) Prefer occasional, heavy storms rather than frequent rain. Freezes in CA: 1932, 1972, 1990 (as low as 5 deg. F) Thresholds: young: 24 deg. F, old: 15 deg. F Rule of thumb: Eucs will be successful where citrus and olive succeed – near same moisture and warmth requirements. Also said for oaks. Shed leaves: 1. Lower ET and water loss 2. Reduce surface area exposed to solar radiation.
Soils
Commonly found in heavy clay soils (AUS), well-drained loamy soil ideal (CA). On river banks or flood plains, upper valley Ideal water table at 8 to 10 ft below surface, some tolerate up to 30 ft Generally don’t grow in standing water, E. camaldulensis an exception Roots: reach 100 ft laterally, 60 ft vertically Habitat Potential and Species Interactions Eucalyptus supports native biodsiversity and richness. Red-shouldered hawks prefer nesting in Eucalyptus species over natives, tree height and diameter main factors Biological control to protect Eucalyptus, via parasitoids Redgum lerp psyllid and longhorned borer Supports pollinators
Survival, Reproduction, Fitness
E. camaldulensis is predominantly an outcrosser, selfing = reduced reproductive fitness Flowers late spring to midsummer Pollinators: Insects, also birds and small mammals Fruits develop and mature as little as 4 months Seed drop can be aided by wind, and dispersal by flood, otherwise no dispersal Floods aid germination, but not necessary Time from planting seed to first seed produced is ~5 years Seedlings susceptible to heat stress and immersion. At 2 months can survive saturation for 1 month. Aerenchymatous roots.
Eucalyptus Management Understory fuel reduction, burned or by hand Stand thinning or removal Stumps resprout: Apply herbicide to cambium circumference Grinding Tarping Disposal: firewood, chipping, burn piles
References
Benyon, R.G., Marcar, N.E., Crawford, D.F. and Nicholson, A.T. (1999) Growth and water use of Eucalyptus camaldulensis and E. occidentalis on a saline discharge site near Wellington, NSW, Australia. Agricultural Water Management 39, 229-244. Boland, D.J., Brooker, M.I.H., Chippendale, G.M., Hall, N., Hyland, B.P.M., Johnston, R.D., Kleinig, D.A. and Turner, J.D. (1984) Forest Trees of Australia. Nelson and CSIRO, Melbourne. Bren, L. (1990) Red Gum Forests. In Mackay N. and Eastburn, D. (eds) The Murray. Murray-Darling Basin Commission, Canberra, 230-242. Brooker, M.I.H. and Kleinig, D.A. (1999) Field Guide to Eucalypts, South-eastern Australia. Volume 1, Bloomings Books, Hawthorn. Brooker, M.I.H., Connors, J.R., Slee, A.V. and Duffy, S. (2002) EUCLID: eucalypts of southern Australia (CD Rom), CSIRO Publishing, Collingwood. CAB International. (2000) Eucalyptus camaldulensis. Forestry Compendium Global Module. CAB International, Wallingford, UK. Chesterfield, E.A. (1986) Changes in the vegetation of the river red gum forest at Barmah, Victoria. Australian Forestry 49, 4-15. Costermans, L. F. (1989) Native trees and shrubs of south-eastern Australia,Weldon, Sydney. Cunningham, G.M., W.E.Mulham, P.E.Milthorpe and J.H.Leigh (1981) Plants of Western New South Wales, Soil Conservation Service of New South Wales. Dalton, K. (1990) Managing our river red gums. Soil Conservation Service of New South Wales, Sydney. Dexter, B.D. (1978) Silviculture of the River Red Gum forests of the central Murray floodplain. Proceedings of the Royal Society of Victoria 90, 175-194. Doran, J. and Brophy, J.J. (1990) Tropical gums – a source of 1,8-cineole-rich Eucalyptus oil. New Forests 4, 157-178. "Eucalyptus Camaldulensis." Australian National Botanic Gardens - Botanical Web Portal. Web. 20 Apr. 2011.