EUCALYPTUS GENETIC RESOURCES IN FLORIDA, USA ¹

by

D.L. Rockwood
Department of Forestry,
University of Florida,
Gainesville, FL 32611 USA

INTRODUCTION

Numerous Eucalyptus species have been evaluated in various edaphic and climatic sites in Florida. From 1965 to 1984, U.S. Forest Service research focused on the best of 67 species for southern Florida (Geary et al., 1983). North Carolina State University from 1971 to 1986 systematically tested over 100 species in northern Florida (Cunningham and Mott, 1985). Since 1979, the University of Florida's efforts have been directed toward nine species for use in the state (Rockwood et al., 1988).

Florida may be divided into three regions based on general climatic conditions (Table 1). Southern Florida has subtropical and tropical environments with sandy to organic soils varying from droughty to wet. Central Florida receives slightly less rainfall and has more frequent and less predictable frosts. Northern Florida is temperate, with frosts frequent and severe enough to restrict the use of most eucalypts. Frosts in all regions typically occur after periods of warm weather. Annual rainfall in the state follows a bimodal distribution, with a major peak during the summer and a minor concentration in the winter.

Table 1.
Characterization of regions in Florida in which Eucalyptus species have been evaluated

Testing and propagation of these species under Florida conditions have resulted in genetic materials that may be desirable in similar areas where frost-hardy/resilient, fast-growing, well-formed eucalypts are sought.

GENETIC RESOURCES

The current extent of tested Eucalyptus genetic resources in the state has been largely defined by major frosts that occurred from 1982 to 1985, e.g., as low as -6°C for more than 18 hours in southern Florida in January 1985. For southern Florida, considerable numbers of E. grandis Hill ex Maid. and E. robusta Sm. are available. For central and southern Florida, E. camaldulensis Dehnh. and E. tereticornis Sm. materials have been developed. For areas of frequent frosts, testing has produced desirable genotypes of E. viminalis Labill., E. nova-anglica, E. camphora R.T. Bak., and E. amplifolia Naudin.

GERMPLASM REQUESTS

To facilitate specific requests for seedlots/clones, a directory tabulating seed inventories, seed orchards, clone banks, and genetic tests will be made available by the end of 1988.

Research level requests for seedlots will be met with seed in storage at the National Tree Seed Laboratory, USDA Forest Service, or at the University of Florida. Commercial quantities of seed will be arranged with International Forest Seed Company and Lykes Brothers, Inc. Clonal requests will be met as possible with materials available at Hartman's Plants Inc. or the University of Florida. Charges will be made to meet the costs of fulfilling germplasm requests.

Please contact the author of this article for additional information.

REFERENCES

Cunningham, M.W. and Mott, R.L. 1985 Micropropagation of Eucalyptus viminalis. In: Proceedings 18th Southern For. Tree Imp. Conf., pp. 56–65.

Dvorak, W.S., Franklin, E.C. and Meskimen, G. 1981 Breeding strategy for E. robusta in southern Florida. In: Proceedings 16th Southern For. Tree Imp. Conf., pp. 116–122.

Franklin, C. 1987 Four generations of selection in Eucalyptus grandis demonstrate valuable methodology for minor tree species. Southern Coop. Series Bull. 324: 1–8.

Geary, T.F., Meskimen, G.F. & Franklin, E.C. 1983 Growing eucalypts in Florida for industrial wood production. USDA For. Serv. Gen. Tech. Rpt. SE-23.

Meskimen, G.F. 1983 Realized gain from breeding Eucalyptus grandis in Florida. USDA For. Serv. Gen. Tech. Rpt. PSW-69: 121–128.

Meskimen, G.F., Rockwood, D.L. & Reddy, K.V. 1987 Development of Eucalyptus clones for a summer rainfall environment with periodic severe frosts. New Forests 3: 197–205.

Reddy, K.V., Rockwood, D.L. & Meskimen, G.F. 1986 A strategy for converting an Eucalyptus grandis genetic base population to a seedling seed orchard. In: Proceedings IUFRO Conf. on Breeding Theory, Progeny Testing, and Seed Orchards, pp. 613–621.

Rockwood, D.L. 1985 Development of woody biomass cultural systems for Florida. In: Biomass Energy Development. Plenum Publishing Corporation. pp. 85–94.

Rockwood, D.L., Comer, C.W., Conde, L.F., Dippon, D.R., Huffman, J.B., Riekerk, H. & Wang, S. 1983 Final Report: Energy and Chemicals from Woody Species in Florida. Oak Ridge National Laboratory. ORNL/Sub/81-9050/1. (205 pp.).

Rockwood, D.L. & De Valerio, J.T. 1986 Promising species for woody biomass production in warm-humid environments. Biomass 11: 1–7.

Rockwood, D.L., Dippon, D.R. & Lesney, M.S. 1988 Woody Species for Biomass Production in Florida. Final Report 1983–1988. Oak Ridge National Laboratory. ORNL/Sub/81-9050/7. (153 pp.).

Rockwood, D.L. & Geary, T.F. 1982 Genetic variation in biomass productivity and coppicing of intensively grown Eucalyptus grandis in southern Florida. In: Proceedings 7th N. Amer. Biol. Workshop, pp. 400–405.

Rockwood, D.L., Kellison, R.C., Franklin, E.C. & Meskimen, G.F. 1986 Operational advanced generation improvement programs for minor species in the South. Southern Coop. Series Bull. 309: 27–37.

Rockwood, D.L., Reddy, K.V., Warrag, E.I. & Comer, C.W. 1987 Development of Eucalyptus amplifolia for woody biomass production. Aust. For. Res. 17(2): 173–178.

¹ Abridged version of manuscript for FGRI, received July 1988.