The ecology of Athrotaxis D. Don (Taxodiaceae) II. The distributions and ecological differentiation of A. cupressoides and A. selaginoides

Abstract

Athrotaxis selaginoides and A. cupressoides are potentially interbreeding species with partly overlapping ranges. The two Athrotaxis species occur in a wide range of floristic types, with A. selaginoides being concentrated in thamnic and implicate rainforest communities and A. cupressoides in open montane communities. As is consonant with its distribution pattern and the cold resistance of its adult foliage, A. cupressoides seedlings are more frost resistant than those of A. selaginoides. Preliminary experiments showed no difference between the two species in resistance to waterlogging or drought. However, stand structure data indicate that A. selaginoides can survive better in shaded conditions than its congenor. This pattern of ecological differentation is consistent with an origin by parapatic speciation.