Effects of Different Rehabilitation Methods and Soil Parameters on the Establishment of Forest Tree Seedlings in a Degraded Forest
The degradation of forests not only results in the loss of productive timber but also many other socio-economic and ecological problems. Thus, rapid forest recovery of the logged-over forest is important. Amongst the strategies that can be used to establish productive forest are selection of plan...
Saved in:
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English English |
| Published: |
2000
|
| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/10537/1/FP_2000_24.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | The degradation of forests not only results in the loss of productive timber but also
many other socio-economic and ecological problems. Thus, rapid forest recovery of
the logged-over forest is important. Amongst the strategies that can be used to
establish productive forest are selection of plant species, methods of establishment
and subsequent vegetation management techniques. Therefore, the objectives of
this study are: 1) to identify suitable methods for rehabilitation of logged-over
forest and 2) to identify the most important soil parameters affecting seedling
growth.
The study was carried out on a degraded logged-over lowland tropical forest,
located in Pasoh Forest Reserve, Negeri Sembilan, Peninsular Malaysia. Four
rehabilitation methods tested were: Tl for line planting, with lines set from west to
east with a width of 3m, 5m and 10m and distance between lines was 10m; T2 for gap planting of 1 0m x 1 0m x 5/ha; T3 for gap planting of 20m x 20m x 5/ha; and
T4 for gap planting of 1 0m x 1 0m x 9/ha. The lines and gaps were planted with
three timber species namely Azadirachta excelsa, Hopea odorata, and Vitex
pubescens. The suitability of the methods was evaluated by measuring seedlings
survival, biomass production, changes in soil properties and cost establishment.
One year after planting, height increment of seedlings of Azadirachta excelsa and
Hopea odorata was measured. Vitex pubescens was not included because there was
no visible growth increment during the one-year period. Soil samples from the
surface soil were collected from the vicinity of the seedlings for the determination
of physical and chemical properties. Statistical analysis was conducted in order to
establish relationships between soil parameters and seedlings growth.
The results showed that there were no significant difference in the survival of the
seedlings of all species one-year after planting and they adapted quite well to
degraded soil conditions. This implies that all the rehabilitation methods and
species are suitable for rehabilitation of degraded logged-over forest in this area.
However, in term of biomass production Tl was found to be the best method of
rehabilitation but in term of cost T2 was found to be the cheapest. The simple regression equations between soil parameters and height increment
showed that the soil parameters limiting the growth of Azadirachta excelsa are
thickness of A-horizon, texture, penetration resistance, available water capacity,
organic matter, and exchangeable Ca and Mg. For Hopea odorata, the limiting growth factors are thickness of A-horizon, macro-pore space and penetration
resistance. However, the multiple linear regressions showed that the growth of
young seedlings Azadirachta excelsa, and Hopea odorata is affected not only by
single soil parameters but also by an interaction of several soil parameters. |
|---|