ECOLOGY AND VEGETATION COMPOSITION AT HIGH LAND PEAT IN TOBA PLATEAU, NORTH SUMATERA, INDONESIA
Loading...
Date
2010-08
Authors
AZVI, TAUFIQ SIDDIQ
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
This study was conducted at the highland peats of Toba Plateau in North Sumatera,
Indonesia to determine the plant diversity, soil textures, soil nutrient contents, air
temperature, humidity and precipitations of the highland peat areas. In addition, bird
observations and local human activities were recorded. Four Sampling plots of sizes
100m x 100m (4 ha) were established in the study area and the plots were further
divided into 400 subplots each measuring 10 m x 10 m. Four sampling sites were
represented by (a) Secondary forest (flooded area and dried area), (b) mining area,
(c) pine forest and (d) agriculture area. A total of 60 plant species from 40 families
were identified. Dry area contains the higher number of species which were 55
species from 38 families. Flooded secondary forest area had 24 species from 19
families while mining area had 10 species from 8 families. Eighteen species from 16
families were recorded from the pine forest and 1 0 species from 9 families were
found in agriculture area. Two species of fern, Dicranopteris pubigera
(Gleichiniaceae) and Blechnum indicum (Blechnaceae) were the common species
recorded during this study. Shannon-Wiener Diversity Index (H') showed that the
highest diversity index was in flooded area (2.17) and the lowest was in mining area
(0.81). The percentage of invasive (weedy) species was very high with 68%, whereas
native species was only 32%. Based on modified Morisita's index similarity,
vegetation at Toba highland peat can be divided into three groups. The first group
was found on dry area and pine communities and the second group was on mining
XVl
area and agriculture area and the third was flooded area. Soil colour of highland peat
ranges from very dark brown colour (lOYR 2/1) to very black colour (lOYR 2/2),
bulk density ranges from 0.23 g/cm3 to 0.40 g/cm3
• The peat depth ranges from 50
em to 85 em in most places but in agriculture area the depth was 2 m and in mining
area more than 9 m. The soil acidity ranges from 3.58 to 4.72. The soil nutrient
content nitrogen (N) ranges from 4,500 ppm to 13,800 ppm, phosphorous (P) from
14.31 ppm to 288.90 ppm, potassium (K) from 11.7 ppm to 280.8 ppm, calcium (Ca)
from 22.0 ppm to 434.0 ppm and magnesium (Mg) from 4.8 ppm to 100.8 ppm.
Generally, the temperature of these study sites was cool which was similar to other
highlands. Therefore, these areas are good for cultivated of seasonal crops. A total of
21 birds species belonging to 15 families were recorded during this study. The
species diversity index of pine community area was the highest with the value of
2.52, whereas at mining area no species was found. Bubulcus ibis was the common
bird species with 13 individuals recorded during 15 days of observation. Farming and
peat mining were the main human activities observed at highland peat area
Description
Keywords
ECOLOGY AND VEGETATION COMPOSITION