Tropical rain forests are among the most complex natural habitats in the world and
widely recognised as areas of high species diversity of both flora and fauna. Despite
their biological and ecological importance tropical rain forests throughout the world
are coming under pressure to be exploited for timber resources. Where management
of rainforests for timber production is carried out on an unsustainable basis, serious
degradation of the forest ecosystem may result, followed by loss of forest cover
and/or species extinction. Therefore, there is a vital need to understand the effects of
forestry practices on these diverse ecological systems and on individual species.
Vertebrates like birds and primates have been widely studied and recognised as a
key indicator species for environmental stress. Anurans (amphibians) have also been
identified as potentially valuable indicators of some environmental changes. The
small home ranges and relatively limited dispersal ability may render amphibians
useful for monitoring the effects of local environmental pertubations. In addition,
their moist permeable eggs and skin also make them good bioindicators of
environmental stress. Amphibians are also important in the food chain and nutrient
cycling. They represent a high quality prey item (high in protein and phosphorus
content) to predators. They may also play a unique role in forest nutrient cycling by
regulating populations of soil invertebrates responsible for the mechanical
breakdown of organic material.
Given both the important roles and functions of amphibians in forest ecosystems and
the significant impacts of logging on forest ecoystems, an understanding amphibians
in relation to forestry practices is required. Relatively few studies have focussed on
the impact of logging on amphibians especially in the tropics. Those that have been
undertaken have related mainly to temperate regions where the logging is usually
clear felling and they have concentrated either on single species or on single genera.
Therefore, this study will attempt to address this gap of knowledge about the
impacts of selective logging on the abundance of anurans in the rain forests of
Kalimantan, Indonesia. The study was undertaken from November 1994 to July
1996 at Camp 92, Central Kalimantan. Three samplingmethods were used in this
study e.g. pitfall traps, searched quadrats and night riparian transects.
The results demonstrate that logging had a significant effects on the abundance of
anurans and anuran species composition. Logging had a strong influence on
vegetation cover, which in turn affects the temperature and humidity. Logging also
affects the physical characteristic of the streams especially the bottom substrates.
The combination of these associated factors strongly affects the abundance of
anurans. The challenge in research for future researchers of amphibian-forestry
relationships is to identifying realistic timber harvest prescriptions that best maintain
those components of the forests biological legacy that are essential for healthy
amphibian populations and forest ecosystem as a whole.