By Dr Hjh Dulima Jali, University Brunei Darussalam

1. BARRIERS TO SEEDLINGS
REGENERATION IN FIRE-DAMAGED
TROPICAL PEATLAND OF BRUNEI
DARUSSALAM
International Conference on Wetland Forest, 22-23
March 2012, Rizqun International Hotel,
Bandar Seri Begawan, Brunei Darussalam
DR. HJH DULIMA JALI,
GEOGRAPHY & ENVIRONMENTAL STUDIES PROGRAMME,
UNIVERSITI BRUNEI DARUSSALAM

2. Introduction
Destruction of Southeast Asia’s peat swamp forest is widely
acknowledged to be a serious problem, causing
degradation of water catchments, losses of biodiversity and
exacerbating rural poverty.
Most countries are now attempting to solve the problem by
protecting remaining forest and launching large restoration
project to meet local and national objectives, including
countries’ international obligations following the United
Nations Conference on Environment and Development.
Large-scale restoration of complex tropical peatland forests is
a comparatively modern dilemma, which has been
approached in a variety of ways.

3. Selection of Approaches
• To select an appropriate approaches to forest restoration a manager
needs to asses actual and potential levels of natural
regeneration and this demands a high inputs of ecological
information of each site.
• It also requires an understanding of the factors limiting
successional change and increases in desired species towards the
desired objectives.
• Directing natural successional processes towards the desired goal
requires an understanding of the processes driving succession and
limitations that halt natural recovery.
• These include:
− Functional hydrological condition.
− Soil ConditionNutrients status and cycling
− Energy flow processes

4. Why need to identify factors that hamper / arrest
regeneration processes?
It is essential to understand the mechanisms of
regeneration and succession and the ecological
dynamics of an ecosystem for effective and realistic
management planning.
These are crucial for the interpretation of the high
spatial-temporal variability found in post-fire species
performance.
Such knowledge also necessary to assess the
potential of different regeneration mechanisms to
cope with ongoing land-use and climate change.

5. UNDERLYING CAUSES HALTING / ARRESTING
NATURAL SUCCESSION
Many studies throughout the neotropics tropical forests
have shown that a number of interacting factors may
impede tropical forest natural regeneration.
These include :
Disturbance: fire, Drought, herbivories, anthropogenic
Site Resources: water, soil nutrient availability
Competition from weeds.
Roots competition.
Plants and propagule availability: Seeds banks, seed rains
Seed dispersal limitations,
Seeds / seedlings predation
Distant from existing forests

6. Identifying the Limitation

7. Study Area
This study was conducted in the Belait - Badas Peat Swamp, in Brunei Darussalam (4°15'-4°39'N, 114°05'-
l14°29'E) an area of state land statute under the jurisdiction of Forestry Department of Brunei

8. The Study Area

9. Objectives of the Study
To develop a better understanding of the
underlying ecological processes in regeneration of
fire affected peat swamp forest of Badas, Brunei
Darussalam
To investigate / identify the biophysical barriers to the
colonization and natural regeneration of the plant
communities in burnt areas that have been invaded by ferns
and sedges.

10. Methods
o Seedlings of several timber three timber species
Agathis alba, Shorea pachyphylla, Dryobalanops
rappa and non-timber tree species were planted in
each transects and their growth were monitored for
three years at 1 – 3 intervals.
o The growth of naturally established peatland
species were also monitored.
o Seeds of several typical peatland species ( Timonius
spp, Tetractomia spp, Ficus spp. saga, mempening)
are disperse randomly.
o Treatment: Control (no cutting), clearing weeds.
o Dispersing seeds of non-timber species randomly

11. RESULTS
Factors that dictated natural regeneration of
seedlings are:
Site Hydrological Condition: site particularly the
depth of the water-table
Wet Site
Natural regeneration flourish in site with high water
table ( < 20 cm below surface)
Dominant species: Tetractumia beccari, Eugenia
spp, Litsea spp, Hoorsfieldia crassifolia.

13. Dry Sites
Vigorous growth of early post fire colonizers
Stenochlaena palustris, Pteridium aquilinum and
Blechnum indicum that cover almost the entire surface
with their strangling stems or dense leaves
This condition significantly hamper the establishment
and growth of seedlings.
At least five species of woody plants - Teminius,
Horsfieldia, Syzygiumspp, Ficus and Uncariaspp have
the capacities to germinate directly within the less dense
stand of ferns and grasses, indicating these species high
competitive ability and adaptability to a wide range of
abiotic circumstances.

14. Survival Rates of planted seedlings
Timber Seedlings 90 %
Control 0% <2%
Cut weeds Once 0% 3%
1 – 3 months cut 65 – 85 % 70 -85 %
Survival of Each species group
Agathis 70 -80 %
Dryobalanops rappa 60 – 75 %
Shorea pachyphylla (1 yr) 80 – 90 %
Non-timber species 85 – 95 %
Environmental condition ( 2005 – 2009) is relatively good with no lengthy
rainless period.

15. Competition with ferns and grasses
If seedling managed to establish among the ferns their
growth are greatly reduced.
Seedlings are overgrown by the ferns and remain covered
and hidden between the ferns resulting in deformed
stems.
Demonstrated by the growth of planted seedlings,
especially the Agathis seedlings.
The seedlings growth is boosted as soon as they escaped
from the ferns that are when the ferns are removed.
Controlling the growth of ferns and grasses caused
significant changes in the species composition as more
seedlings appear particularly Teminius spp and several
species of Ficus, Eugenis, Calophyllum and Uncaria.

16. Agathis seedlings
covered by ferns

17. Growth of Agathis after released from ferns, with deformed stems. Growth
increased dramatically once seedlings emerged above the fern canopy

18. Inhibitory characteristics of ferns & sedges

19. Growth of fern after fire

22. Lack of seeds
The seed bank is likely to be exhausted by the fire
because the organic nature of the substrate would
have produced intense heat that would have
destroyed any available seeds.
More trees regenerating nearer to undisturbed forest.
Dominant species are Lithocarpus sundaica
(mempening); Eugenia spp. (ubar); Baccaurea
bracteata ( tampoi antu), Calophyllum spp
(bintangor)

24. Limited dispersal mechanisms & activities
Large treeless areas are unattractive to most frugivorous
dispersers.
Extensive growth of early colonizer of fern and sedges
communities limited dispersal activities given that
grasses and fernlands offer few resources that attract
seed dispersers particularly the birds and small
mammals.
Seeds dispersal therefore appears critical in determining
the diversity, density, and location of natural
regeneration.
Perching sites such as isolated trees can accelerate
ecological succession processes.
Most generating species are birds dispersed

26. Evident of Dispersers

27. Existing surviving trees and distant from forest edge
The existence of surviving timber trees also showed some
influence on the regeneration processes.
These survivors appear to facilitate recolonization as indicated
by the appearance of several different seedlings that establish
around the surviving trees.
They appear to perform a probable mode of dispersal by
acting as perches to birds that play a significant role in the
dispersal of small seeds.
In addition these surviving trees cast shade that limit the
growth of ferns and grasses that otherwise limit the
germination of tree saplings.
There is no indication that the surviving trees act as seed
sources as those seedlings are of totally of different species.

28. Regeneration around
surviving trees

29. Application of assisted natural regeneration (ANR)
As clearing eliminates the fern while enhancing the
performance of most tree seedlings suggests that
planting trees to overcome dispersal limitations and
produce a shade cover is the best way to eliminate the
ferns.
Once trees are established, they may act as regeneration
nuclei by attracting seed dispersers and providing
favorable growing conditions, thereby accelerating
natural regeneration.
So application of assisted natural regeneration (ANR)
offers efficient, low-cost forest restoration method that
can effectively hastened regeneration of vegetation.

30. IMPLICATION FOR PRACTISE

31. Conclusion
There are a several interacting factors that impose barriers for
the growth and survival of this seedling and arrest the natural
succession.
The results of the study emphasize the predominant effect of
competition, effective seed dispersal (a combination of
dispersal and survival) and hydrological regime in affecting
species composition and the seedling growth.
It also highlights the need for management intervention in
restoring the peatland floristic diversity.
Approach of overcoming the barriers to, and accelerate
natural successional processes are by removing or reducing
the barriers: - competition with weedy species, manipulation
of tree stands and addressing the recurrence of fire

33. Growth of Agathis & Drybalanop rapa

34. Excellent growth of Shorea pachyphylla,

35. Problems
Defoliation and resprouting
of Dryobalanops rappa.

36. Damage by animals

37. Unknown cause of death: Most
likely root predation

38. THREATS : Logging

39. Threats: Sand Mining

40. FIRE (June 2009)

43. Oct 2010

45. THANK YOU FOR
YOUR
ATTENTION