Ecoregional Assessment of Biological Diversity in East Kalimantan

East Kalimantan Ecoregional Assessment: Chapter 1 – Background & Analysis Process
4). Landscape context
Figure K: Isolation ranking in karst forests
a. Isolation
Target ecological system occurrences that have
others of the same type close-by are considered more
viable because highly mobile species with large
diurnal ranges, or those that have local seasonal
migrations or seasonal shifts, could more easily
utilize the occurrence if there is a close ‘stepping
stone’ of a similar habitat. These habitat types are
also considered to have a greater chance of being
repopulated more rapidly by other similar habitat
patches in the event they were burnt or otherwise
damaged. Figure K shows the distances that were
measured in a group of Lowland Limestone
Rainforest occurrences. Occurrences in the lowest
quartile for area of that system type (i.e. smallest
size) were not included in the rankings for distance
to nearest like occurrence. This was one way to
eliminate all the artifactual and/or assumed to be
non-viable vestigial occurrences of ecological
system types.
b. Condition around a target ecological system
occurrence
The condition of forest within a buffer zone, set at
two (2) kilometers around the occurrence, was
ranked by the same method established for internal
condition ranking above. The width of this buffer
zone was set somewhat arbitrarily, but is
considered to be wide enough to reflect the habitat
that would immediately impact an occurrence.
Information from the management plan for Lore
Lindu National Park, Central Sulawesi (TNC 2002)
for example, indicates that there is little detectable
human impact on forests that are more than 500
meters from a village. In fact there is often a very
sharp interface between primary forest and lands
that have been converted for agricultural purposes
for some time. This may not be the case however,
for the impacts associated with hunting of “bush
meat” for personal use or for markets.
Figure L: Contextual ranking of karst forest
If there were two or more disturbance types within the 2 km buffer zone of a given target
occurrence - these were ranked according to the method detailed in the following section.
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