The Valley of a Thousand Plants is the title of the publication described as the "first edition of an inventory of flora in the Dora Creek catchment".

It is the culmination of years of painstaking work by Dr Terry Annable and Dr Howard Fisher.

The pair are biologists and semi-retired lecturers at Avondale College of Higher Education, in Cooranbong.

Dr Annable says the study provides "detailed documentation about our local flora".

The title is apt as it lists more than 1000 species of native plants representing 164 different plant families.

"This high level of biodiversity confirms that the Dora Creek valley is a very significant botanical region requiring protection into the future.

"Dora Creek is the largest catchment flowing into Lake Macquarie and it is known to have at least 47 different types of ecological communities."

Among the activities posing a threat to the region are processes witnessed the world over, such as land clearing, urban development, intensive farming, non-native invasions, use of herbicides, climate change, pollution and inappropriate collection, he said.

■ Copies of the publication are available from the secretary, School of Science and Mathematics, Avondale CHE, Cooranbong, phone 4980 2122. It costs $12 or $15 by post.