Phytophthora cinnamomi in indigenous plant communities in New Zealand

Publisher Website
Google Scholar
Abstract
Phytophthora cinnamomi has been isolated from roots of 25 species of plants found in four indigenous communities in three of which severe chlorosis, dieback and mortality occur. The most severely affected are dense kauri (Agathis australis) regrowth stands 80–100 years of age in the Waitakere Ranges near Auckland where both overstorey and understorey species are severely damaged. The other diseased communities are mixed scrub on eroded hill soils at Kaitenteri near Motueka and Coriaria sarmentosa scrub in Golden Downs State Forest near Nelson. The fourth community is healthy Dacrydium cupressinum forest at Harihari, South Westland. From these and other records it is obvious that P. cinnamomi is widely distributed in native communities in New Zealand. It is not possible to determine whether the fungus is indigenous or introduced. It seems clear, however, that P. cinnamomi is now playing a role in natural succession. While its selective influence is likely to be subtle and protracteprotracted in most areas. the fungus is causing severe damage in the three localities above. At Kaiteriteri it seems that this disease is due mainly to the influence of eroded soils on infection and root regeneration: in the Waitakere Ranges, to abnormally heavy summer rainfall, greater susceptibility with increasing age of tree, and increased waterlogging as the canopy deteriorates.

This publication has 4 references indexed in Scilit: