DIVERSITY AND ENERGY POTENCY FROM TROPICAL FOREST PLANT SPECIES IN EAST KALIMANTAN, INDONESIA
Rudianto Amirta
Faculty of Forestry, Mulawarman University, Samarinda, East Kalimantan, INDONESIA
Tel.:+62-541-748683; Fax:+62-541-737059
Email: ramirtafahutan.unmul.ac.id / rudiantoamirta@gmail.com
ABSTRACT
Diversity and energy potency from tropical forest plant species was studied in various type of forests to point out their suitabilty
to be used as an alternative energy feedstock, specifically for the electricity generation, ethanol production and biorefinery in
East Kalimantan, Indonesia. Diversity of plant species was evaluated by making more than 50 sampling plots with 20mx20m
size approximately in every forest type studied. Concurently, the energy properties of plant biomass such as proximate and
ultimate compositions were also analyzed using ASTM methods. The results showed that more than 50 species of tropical
trees and wood shrubs were grown in the secondary forest. The presence of them was classified into two different growth of
origins: natural and artificial plantation, and also three different categories of plant resources: tree species from logged over
forest, commercial fast growing plant tree species for the fiber production and woody shrubs. In general discussion, we found
V. pinnata (Laminaceae) was the highest dominant of forest plant species in the secondary forest area studied and it was
indicated by the highest importance value index of 32.72 from the total population in the area, and followed by
N. gigantea,
13.59 (Rubiaceae) and
M. pearsonii, 13.15 (Euphorbiaceae). Instead of
V. pinnata (Laminaceae), the results also showed
that Euphorbiaceae was found as the other dominant and important family in the secondary forest area according to the
highest importance value index measured. The important family of Euphorbiaceae was represented by the presence of
M.
pearsonii, M. triloba, M. hypoleuca and also
H. brasiliensis with importance value index were 13.15, 12.63, 10.23 and 10.12,
respectively. Furthermore, we also found that wood biomass from
V. pinnata was achieved the highest calorific value (18.00
MJ kg
-1). Moreover, M. triloba, L. gracilis, and H. brasiliensis were the second and third place with the value of 17.11 MJ kg
-1
and 16.93 MJ kg
-1, respectively. In general discussion, the average of carbon, hydrogen and oxygen contents of plant
biomass collected in the current study indicate that they belong to good quality of fuel biomass, and suitable to be used as
green energy feedstock. Based on those findings and discussion, we concluded that plant species naturally grown on
secondary forest area in East Kalimantan, Indonesia had the potential biomass that could be used as sustainable feedstock
for green energy production. The wood biomass composition was acceptable as feedstock for thermochemical conversion of biomass to produce heat or energy, ethanol and other biorefinery products.
Keywords: diversity, electricity, energy. tropical forest, Vitex pinnata
