Ecoregional Assessment of Biological Diversity in East Kalimantan

East Kalimantan Ecoregional Assessment: Chapter 2 – Target Ecological Systems
• Fire
Due to the fewer roads present in this forest system type, because of the legal logging
restrictions, fire tends to occur less frequently than in the lower elevation forests. But
contiguity of this forest type with adjacent more heavily used systems, such as lowland
rainforest and karst forest, the danger of wildfire spread persists. Impacts are particularly
damaging in the montane systems because of their removal of multiple-layers of
vegetative habitat features – that is, the bole climbers, vines, ferns, tree orchids, mosses
and fungi present at every level of the forest canopy. Each of these habitat features serves
as home to numerous, and probably as yet undocumented endemic species of
invertebrates and small vertebrates.
• Alang alang (Imperata cylindrica) spread.
Recently in East Kalimantan, Alang-alang grasslands have extended widely into Lowland
Rainforest areas. Alang-alang is a fire disclimax species, which prevents natural
rehabilitation of disturbed forest. It mainly results from conversion of forests to kebun
(garden plots) on infertile soils and not from slash and burn (swidden) agriculture widely
practiced by traditional people (Kiyono and Hastaniah 2000). The lack of regulations to
prevent clearing for one crop rotation, after which land is permanently abandoned, is a
major factor in the spread of Alang-alang grassland and the permanent conversion of
Lowland Rainforests. Such a source of invasive species may bring it into the Lower
Montane region when or if this forest type begins to suffer substantially from
deforestation in the eventuality that the lowland forests are depleted.
• Swidden agriculture.
MacKinnon et al. (1996) regard traditional swidden farming as causing little damage to
the environment. Fallow land from swidden farming usually becomes secondary forest,
and ultimately develops into mixed dipterocarp forest after a fallow period longer than 70
years, if the seeds of primary forest species are provided by retaining nearby
reproductive-aged standing forest (Okimori and Matius 2000). However, new
technologies, increased population pressure and the need for traditional farmers to plant
cash crops have dramatically altered traditional swidden practices and telescoped the
fallow period (Jessup and Vayda 1988). There is a need to identify areas of Lower
Montane/Middle Montane Rainforest where traditional swidden practices can be
maintained and to discourage other farming techniques that are inimical to maintenance
of forest structure and floristics.
• Lack of Strict Enforcement of Government Regulations.
There are existing regulations that forbid logging on slopes greater than 45% or above
600 m a.s.l. (Keputasan Presiden No.48/1983). These regulations should be strictly
enforced because illegal logging in these and other areas is rampant. Logging on high
slopes is particularly damaging, as most of these areas are prone to erosion if they are
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