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- 1081 - 
AERIAL PHOTOGRAPHS FOR CONSERVATION EVALUATION 
Janet Nichol VW. Gordon Collins 
INTRODUCTION 
Interested groups working in ecology and conservation have only relatively 
recentlv realised the need to identify more definite and far-reaching 
aims than "to preserve and enhance the natural beauty of the countryside". 
There is urgent need for a deeper scientific understanding of the environment 
in order to maintain it as close as possible to a state of balance. 
In competition with other land uses such as those of agriculture and 
forestry, however, conservation for wildlife has distinct disadvantages in 
that, even should data on wildlife be available or obtainable, its value 
as a land use is difficult, if not impractical to measure in quantitative 
terms. 
Apart from the need for a greater degree of objectivity in conservation 
evaluation studies, there is a need to consider. in ecological terms. the 
whole of the landscape, including urban and suburban areas, and not only 
those already designated for wildlife conservation. This, however, is 
often difficult, owing to the lack of the necessary information for whole 
areas of countryside, or the inability to collect it efficiently. 
Of the few conservation evaluation studies already carried out, most have 
used different types of data and data collection techniques, different 
evaluation parameters, and different wéightings attached to each parameter. 
However, for a particular level of survey it should be possible to specify 
standardised survey techniques, and the types of data which should be 
collected-within the limits of the resources and technology available for 
data acquisition. At the regional planning level, it seems that aerial 
photographs are replacing ground survey methods. 
It is intended here to consider, from the point of view of air photo capability, 
the collection of data for conservation evaluation surveys, and the major 
parameters used in such surveys. When more is known about the data collection 
process for surveys of extensive areas refinements can be made in data 
evaluation. 
DATA COLLECTION 
The Wildlife Habitat 
Habitats have generally been used as mapping categories, since they are : 
broadly homogeneous units, containing similar internal conditions for wildlife. 
'Habitat' is defined as "that part of the environment at which exchanges 
actually occur between the organisms and the resources which they utilise", 
(Dansereau, 1957). Because animal species to a large extent depend for their 
food and cover on the structure and composition of the vegetation, vegetation 
is generally used as the mapping unit for the wildlife habitat, though other 
non-vegetational features Inter and Intra- Habitat Diversity in Table 1) 
be essential for the existence of some species, and should be considered 
during the data collection stage. 
Habitat Parameters used in Conservation Evaluation 
A composite list of the habitat parameters used by the existing methodologies 
for conservation evaluation of an area of countryside is give in Table 1.