Introduction and Conservation of Casuarina Trees in China

There are four genera and 96 species belonging to Casuarinaceae. The four genera are Casuarina, Allocasuarina, Ceuthostoma and Gymnostoma. Casuarina plants are naturally distributed in Australia, Southeast Asia and archipelagos in Pacific Ocean, with altitude from sea level to over 3 000 meters. Although casuarina trees were introduced into China in 1897, it was in mid 1980s that casuarina trees began to be introduced into China systematically. Then casuarinas genetic resources were collected, reserved and selected in provenance/family/clone levels. And some relative research had been developed on clonal propagation, symbiotic microbe, and so on. Up to now, 2 genera, 23 tree species, more than 200 provenances, 260 families and a lot of clones were introduced into China. By a series of field experiments, some better species, provenances and families for different sites in southern China were screened out, of which genetic resources of Casuarina equisetifolia and C. junghuhniana was in whole naturally distributed regions of provenances and secondary provenances. Since 1990, introduction of Allocasuarina tree species have been paid more attentions to, more than 10 tree species have been introduced into China and have been tested in southern China and southwestern China, which enriched Chinese casuarinas genetic resources. Now the casuarinas tree species introduced are as follows: Allocasuarina campestris, A. dielsiana, A. distyla, A. fraseriana, A. huegeliana, A. humilis, A. littoralis, A. luehmannii, A. nana, A. paludosa, A. pinaster, A. striata, A. torulosa, A. verticillata, Casuarina collina, C. cristata, C. cunninghamiana, C. equisetifolia, C. glauca, C. grandis, C. junghuhniana, C. obesa and C. oligodon. In this paper, casuarinas introduction history, current research, conservation and utilization were reported.