Ecoregional Assessment of Biological Diversity in East Kalimantan

East Kalimantan Ecoregional Assessment: Chapter 2 – Target Ecological Systems
logged. Such impacted forests with high erosion potential in many key water catchment
areas need to be identified and rehabilitated with appropriate native species.
• Increased Hunting Pressure.
Traditionally, inland peoples of East Kalimantan have hunted a range of animals
including all medium to large mammals present in Lower Montane Rainforest.
Additionally, there are now substantial bush meat markets that have been established to
serve the workers of timber companies in the field, for example at Malinau in
stratigraphic unit 1. The dramatically shrinking, and increasingly fragmented populations
of these animals, particularly in the Lowland Rainforest systems due to large tracts of
their habitat being logged or destroyed by land conversion or burning, have increased the
role of the Montane ecosystems to absorb the remaining populations as refuges. For
species such as Asian Elephant and Sumatran Rhinoceros, the upper elevation habitats in
all likelihood provide their last stronghold.
Occurrence Unit Determination
Significant lower montane forests were identified through the use of LandSat imagery to
locate them in the province. The ECA team then consulted with individual experts and
literature sources, followed by limited ground truthing for some sites proposed for inclusion
in the portfolio.
Lower Montane/ Middle Montane Forests cover large expanses around the foothills and midslopes
of mountains. This trend is particularly evident on the western mountainous spine, to
the north of the Central Mahakam Basin and on numerous smaller patches in Malinau, in the
northern part of Kayan Mentarang National Park and to the west of Sangkulirang Peninsula.
These are usually large patches and irregular in shape, occurring from 1000m to 1500m a.s.l.
However, due to compression effects, some may be found with upper limits as low as 600m-
800m a.s.l.
In this ecoregional assessment, each isolated patch of lower and middle montane forest, no
matter how close to other patches, was regarded as a separate occurrence. Rivers were not
regarded as separating this forest type into different occurrences because, at these altitudes,
the rivers are usually found in sharp ravines and may be easily traversed by fauna along
fallen logs, boulders, overhanging vegetation and other debris.
Portfolio Design
The overall goal for Lower Montane /Middle Montane Rainforest ecological system type in
the East Kalimantan Portfolio was 60%. The portfolio achieved 80.54% (stratigraphic unit 1,
85%; unit 2, 68.7%; unit 3, 50%; and none from unit 4).The recognition of occurrences of
this forest type in formally protected areas, coupled with inclusion of strategically important
and high quality watershed polygons for the selected river systems resulted in surpassing our
40