Few problems were experienced in assigning areas to one class or 
another. The outlined areas were transferred directly from the photo- 
graphs to the existing 1:4000 scale planimetric base map. A further 
transfer to a 1:15 000 scale base map was done by conventional drafting 
techniques. 
To accommodate changes that might have occurred between the date of 
photography and the date of the assessment, a series of 70 mm colour 
oblique photographs were taken from a light aircraft at the time of the 
site inspection. The seven separate runs of photographs were located over 
the worst affected areas as identified by the site inspection.  Inter- 
pretation of these photographs caused some minor shifts to be made to the 
boundaries determined from the vertical photographs and gave an indication 
of the rate of deterioration of several of the worst affected areas. 
Three experienced forest scientists (an ecologist, a pathologist 
and a resource assessment specialist) spent ten days on the Island. 
Assisted by local staff they traversed every trafficable road and track, 
visited many vantage points, closely inspected affected areas on foot and 
surveyed the Island from a light aircraft. Old photographs and reports 
were located and used extensively and comparable ground photographs taken 
to provide a historical record. Local knowledge in the form of opinions 
of long-time residents was also gathered. A further collection of soil 
and foliar samples was made from affected trees in widely separated 
locations on the Island. 
Results and Discussion 
Figure 2 illustrates the location and extent of the severely affected 
and lightly affected dieback areas. The severely affected areas total 
approximately 500 ha while the lightly affected areas cover a further 
335 ha. 
In the unaffected areas there are substantial portions of cleared 
land where no pine trees exist especially where the urban development has 
concentrated. The largest continuous area of dieback (320 ha) extends 
from the southeastern corner (Ball Bay) through to the centre of the 
Island (Middlegate and Burnt Pine). In addition there are four other 
major patches including one serious and actively deteriorating area on the 
west coast at Headstone Point. Little change was observed on the 1972 
oblique photographs when compared to the 1968 vertical coverage apart from 
the Headstone Point area. Some lightly affected areas were not identified 
on either type of photographs but were recognised on the ground survey. 
These areas were added to the photointerpreted map and are included in the 
map at Figure 2. 
It was observed that almost without exception the pine could be 
successfully grown in all of the areas of severe deterioration provided it 
was given protection from grazing animals, and, competition from exotic 
grasses and shrubs was held in check during the early life of the tree. 
For example, the forest was completely healthy and weed growth was at a 
minimum on the 40 ha reserve at the southwestern tip of the Island (Rocky 
Point) where complete protection has been afforded to the natural re- 
generation and plantations of pine and other species for at least 70 
years.