Stock Road Orchids

In June 1969, I purchased the land now known as Warrawong Sanctuary. This block fronted fronted Stock Road which runs from Heathfield to Mylor and is about three kilometres long. During the early 1970s I photographed the orchids along the side of Stock Road. These are the photographs. There are only about five species left there today. Why?

Parsons Bands Pteristylis barbata campestris carnea curta blue glossodia gnat grandiflora hare imberbis spotted yellow leptochilla wallflower longifolia lyperanthus macmilliani maculata leopard mayfly menzieii midge mosquito nana nodding nuda odorata onion patersonii pauci1 pauci2 pauci3 pedunculata punctatum rabbit rubra spot spider vittata deformis green leopard palachilla red spotcarnea Only five left! Why?