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A unified framework for the restoration of Southeast Asian mangroves—Bridging ecology, society and economics


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The effect of intensive human intervention, poor socio-economic conditions and little knowledge on mangrove ecology pose enormous challenges for mangrove restoration in Southeast Asia. We present a framework for tropical mangrove restoration. Our proposed restoration framework addresses the ecology, economy and social issues simultaneously by considering the causes of mangrove degradation. We provide a step by step guideline for its restoration. We argue that although, ecological issues are of prime importance, economic and social issues must be considered in the restoration plan in order for it to be successful. Since mangrove ecology is not adequately studied in this region, local ecological knowledge can be used to fill the baseline information gaps. Unwanted human disturbance can be minimized by encouraging community participation. This can be ensured and sustained by facilitating the livelihood of the coastal community. We translated the restoration paradigm into a readily available practical guideline for the executors of the plans. We provide an example of mangrove restoration project that is closely related to our proposed framework. We are optimistic that this framework has the potential for universal application with necessary adjustments.
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A unified framework for the restoration of Southeast Asian
mangroves—bridging ecology, society and economics
Shekhar R. Biswas Æ Azim U. Mallik Æ
Junaid K. Choudhury Æ Ainun Nishat
Received: 11 October 2007 / Accepted: 22 July 2008 / Published online: 9 August 2008
Springer Science+Business Media B.V. 2008
Abstract The effect of intensive human interven-
tion, poor socio-economic conditions and little
knowledge on mangrove ecology pose enormous
challenges for mangrove restoration in Southeast
Asia. We present a framework for tropical mangrove
restoration. Our proposed restoration framework
addresses the ecology, economy and social issues
simultaneously by considering the causes of man-
grove degradation. We provide a step by step
guideline for its restoration. We argue that although,
ecological issues are of prime importance, economic
and social issues must be considered in the restoration
plan in order for it to be successful. Since mangrove
ecology is not adequately studied in this region, local
ecological knowledge can be used to fill the baseline
information gaps. Unwanted human disturbance can
be minimized by encouraging community participa-
tion. This can be ensured and sustained by facilitating
the livelihood of the coastal community. We trans-
lated the restoration paradigm into a readily available
practical guideline for the executors of the plans. We
provide an example of mangrove restoration project
that is closely related to our proposed framework. We
are optimistic that this framework has the potential
for universal application with necessary adjustments.
Keywords Community development
Community participation Experiential learning
Ecological restoration Ecosystem synthesis
Mangrove degradation
Ecological restoration is one of the most challenging
branches of ecology (sensu ‘acid test’ of ecological
theory; Bradshaw 1987) and mangrove restoration is
even more challenging because of the very dynamic
nature of the ecosystem, which experiences tidal
flooding as well as other natural and anthropogenic
disturbances. In Southeast Asia, especially in devel-
oping countries, two approaches to mangrove
restoration have been used: (i) ecological engineering
(Lewis and Marshall 1997; Callaway 2001; Lewis
2005) and (ii) human—ecological problem solving
(Walters 1997). Mangrove restoration in Southeast
Asia is much more complicated and challenging than
the issues addressed by these two approaches for
several reasons. First, although tropical mangroves
are the most diverse and dynamic ecosystems in
terms of species diversity and productivity (Fig. 1;
S. R. Biswas (&) A. U. Mallik
Department of Biology, Lakehead University, 955 Oliver
Road, Thunder Bay, ON, Canada P7B5E1
J. K. Choudhury A. Nishat
IUCN The World Conservation Union, Bangladesh
Country Office, H-11, Road 138, Gulshan 1, Dhaka 1212,
Wetlands Ecol Manage (2009) 17:365–383
DOI 10.1007/s11273-008-9113-7
Saenger et al. 1983), the Southeast Asian mangroves
are the least studied. Second, Southeast Asian coastal
areas are highly populated with poor and margina-
lised people (Iftekhar and Islam 2004). These coastal
people depend heavily on mangroves for their
livelihood. Because of this dependency, people
become a major determinant of the state of mangrove
forests, often, by suppressing natural processes and
must be considered components of the Southeast
Asian mangrove ecosystem. Third, with few excep-
tions, most mangrove restoration efforts in Southeast
Asia have followed a trial and error method without
any explicit and integrated framework, baseline
ecological information, or proper consideration of
community involvement. It is not surprising then that
most of the mangrove restoration efforts have met
with limited success (Aksornkoae 1996; Al-khayat
and Jones 1999; Alongi 1998; Bacon 1987, 1993;
Bandaranayake 1998). Some failed immediately
while others failed several years after initiation (see
review by Ellison 2000). Opinions differ on the
success rate of mangrove restoration programmes.
Successful projects are often reported but failures
rarely (Lewis 2005). However, there is no ambiguity
for the need of mangrove restoration.
The importance of mangroves has been empha-
sised for their unique ecological, economic and
protective functions. The major functions of man-
grove forests include (i) habitat for flora and fauna,
(ii) timber, pole, fuel wood and fiber production, (iii)
diversified non-timber forest products, e.g. tannin,
honey, wax etc., (iv) breeding and nursery grounds
for fish, crustaceans, mollusks and a wide range of
aquatic and terrestrial species, (v) effect on micro-
climate, (vi) protection from wave erosion, (vii)
enhancement of sediment deposition/land accretion,
(viii) input of organic detritus into the coastal zone to
support the productivity of these waters, (ix) com-
bating natural calamities such as tsunamis, cyclones
and tidal surges and (x) amelioration of the environ-
ment by acting as a carbon sink (Macnae 1968;
Fransworth and Ellison 1997; Primavera et al. 2004;
Walton et al. 2006). Protective functions of man-
groves against the most recent tsunami (i.e. 2004)
excelled in their realisation of the significance of
mangroves across the globe for the existence of
people along tropical coastlines Dahadough-Guebas
et al. 2005a, b; Danielsen et al. 2005; Kathiresan and
Rajendran 2005; Barbier 2006). Although contro-
versy continues to exist in the debate of whether the
mangrove belt can provide total protection, there is
no controversy over the significant role of mangroves
as a barrier against natural disasters such as tsunamis
and tidal surges (Kathiresan and Rajendran 2006).
Fig. 1 Geographical
distribution of mangrove
biodiversity (data used from
Saenger et al. 1983)
366 Wetlands Ecol Manage (2009) 17:365–383
The increasing rate of mangrove degradation
(Duke et al. 2007) and lack of significant success in
the scattered mangrove restoration programmes
(Lewis 2000) are exposing tropical coastal commu-
nities to increasing vulnerability. Not only is it
essential to stop mangrove degradation, but it is also
important to restore the degraded tropical mangroves.
This requires a holistic and comprehensive frame-
work that could take the form of both curative and
precautionary interventions. However, to date there is
no such comprehensive framework available.
We propose a framework for the restoration of
tropical mangroves by emphasising two major issues
(i) identifying and addressing the causes of degrada-
tion to prevent further degradation of the existing
mangroves and (ii) developing a detailed practical
guideline for the executors of plans for the restoration
of already-degraded mangroves. We argue that (i)
ecological knowledge is the most important factor for
the success of mangrove restoration and traditional
ecological knowledge can help substitute the baseline
information gaps that exit in Southeast Asian man-
groves, (ii) anthropogenic influence can be addressed
by ensuring sustained community participation and
(iii) sustained community participation can be
encouraged by economic considerations for the
livelihood and sustenance of coastal communities.
Causes of mangrove degradation in the tropics
Tropical mangroves are shrinking rapidly, due to five
major causes: (i) conversion to shrimp/aquaculture
farms (e.g. Bangladesh: Hossain et al. 2001; Gain
2002; Thailand: Spalding et al. 1997; Hinrichsen
1998; Barbier 2000; Barbier et al. 2002; Barbier and
Cox 2002; the Philippines: Primavera 1995, 2005;
Walters 2004; Indonesia: Spalding et al. 1997;
Hussain et al. 1999; Vietnam: EJF 2003; Ecuador:
Lacerda et al. 2002; Honduras: DeWalt et al. 1996)
(ii) conversion to sea salt farms (Prokant and Reeves
2007), (iii) conversion to agriculture (Biswas et al.
2007), (iv) natural calamities (Dahadough-Guebas
et al. 2005a, b) and (v) infrastructure development
and hydrological diversion. These degradations can
be grouped under two broad headings: human-
induced degradation and natural disturbance-related
degradation. The combined effect of the two often
causes a devastating impact as explained below with
a hypothetical diagram (Fig. 2)
Time scale
Ecosystem state
Type I
Recovery after Type II
(absence of Type I)
Type II + Type I
Type II
Fig. 2 Hypothetical
relationships between
disturbance type and
recovery pattern in
mangrove ecosystem. Three
scenarios hypothesized: (A)
Type I disturbances
facilitate degradation of
mangroves. (B) Type II can
be massive and overnight
degradation of whole or part
of a mangrove forest.
However, if there is no Type
I disturbance natural
recovery rate may be high
following Type II
degradation. (C) In the third
scenario, a mangrove forest
first degraded by Type II
(sharp degradation)
followed by Type I leaving
limited chance for recovery
Wetlands Ecol Manage (2009) 17:365–383 367
Human-induced degradation of mangroves and
mangrove habitats can be defined as Type I degrada-
tion and may occur in two forms: (i) conversion of
the newly accreted lands where mangroves develop
naturally into land for human use and (ii) conversion
of productive mangrove forests to other types of
anthropogenic land management. The newly accreted
lands in Southeast Asia have been increasingly
converted into agricultural lands and shrimp and salt
farms, while the productive mangrove areas are being
converted to shrimp farms and for agricultural use
(e.g. Walters 2004). Economic pressure from increas-
ing populations in tropical coastal areas, where the
livelihood of coastal communities is directly related
to mangroves, is considered to be the dominant
driving force behind Type I mangrove degradation
(Fig. 2). Natural calamities such as tropical cyclones,
tidal surges and tsunamis are accelerating the degra-
dation of coastal mangroves. This type can be called
Type II degradation. Climate change is thought to be
the driving force behind the increasing frequency and
intensity of these sorts of natural calamities causing
Type II degradation (Fig. 2).
The mangrove restoration paradigm
Depending on the type of degradation, mangrove
restorations may be of two major types: (i) restoration
of mangroves following anthropogenic degradation
(Type I) and (ii) restoration of mangroves following
natural disturbances (Type II). For Type II degradation,
mangrove recovery relies on ecological principles (i.e.,
secondary succession). However, the rate of recovery
can be increased by planned restoration initiatives.
Type I restoration is more complicated and challeng-
ing. Reliance on only ecological issues is not sufficient.
It requires a holistic approach, by integrating social and
economic issues of coastal communities along with
ecological issues of the mangroves.
The conventional philosophy of ecosystem resto-
ration is to restore the degraded ecosystem to its pre-
degradation state. This raises the question: of whether
it is at all possible to restore a dynamic system.
Furthermore, even if it were possible to rebuild the
ecosystem to its pre-degradation state, the newly
restored ecosystem would remain behind its original
state since changes might take place during the
restoration period (i.e. it will lag in a temporal sense).
Whether total restoration is possible or not remains a
philosophical issue. At the root of this debate (see
Temperton 2007 for details) are questions such as
whether ecosystems are cohesive (Clements 1916),
the sum of few parts (Gleason 1917), whether
ecosystems go through alternate stable states (Suth-
erland 1974) or whether ecosystems start to develop
in a new direction after crossing an ecological
threshold (Hobbs and Norton 1996, 2004; Walters
2000). Often it is not practical to insist on total
restoration of a mangrove ecosystem to its pre-
disturbance state. We acknowledge that there might
be a gap in the ecosystem state between a pristine
(undisturbed/low intensity and frequency of natural
disturbance) and a restored ecosystem (see Fig. 3).
The aim of restoration should be to minimise the gap
between the undisturbed (naturally disturbed) and a
restored ecosystem states (see A
and D
Fig. 3). This coincides with the restoration principle
of the Society for Ecological Restoration (2002) that
defines restoration as ‘the process of assisting the
recovery of an ecosystem that has been degraded,
damaged, or destroyed.’
During restoration, ecologists manipulate the
structural and compositional components of an eco-
system so that it can be revitalized. In common
mangrove restoration practices; structural manipula-
tion includes planting trees and hydrological
engineering. Compositional manipulation includes
seeding and planting multiple species to increase
species diversity and habitat recovery. The underly-
ing assumption is that the important structural
components of an ecosystem are trees, land and
water. However, in Southeast Asian countries, human
influence on mangrove ecosystem is so great that
humans must be considered as a component. There-
fore, in addition to fine-tuning the previously
suggested ecological engineering principles (Lewis
2005); we suggest to incorporate the important social
and economic issues of coastal communities. More
specifically we emphasize ensuring community par-
ticipation and facilitating the livelihood of people. In
earlier participatory mangrove restoration projects,
only community participations were included but
limited priority was given on the issue of livelihood.
As such the participations were ineffective.
Of the controlling factors in our proposed resto-
ration framework, ecology (sensu ecological
engineering for restoration of ecological systems) is
368 Wetlands Ecol Manage (2009) 17:365–383
independently dominant. It has an upwards pulling
force (i.e. ecologists try to improve the ecosystem)
and any compromise on ecological principles might
lead to collapse of the entire restoration effort.
Society and its economy are very much inter-related
and always act together instead of as isolated factors.
Society pulls horizontally (i.e. they like to go as
usual) and the economy keeps society either hori-
zontally upward (when financial benefits are ensured)
or downward (when there are no financial benefits).
The success of restoration might show an upward
pattern when both factors are considered, whereas it
might be a humped shaped curve when there are no
financial benefits to society (Fig. 3). It could be
argued that (i) economic valuation of the ecosystem
services and (ii) the development of forest area
provide benefits to society (long term benefits from
forest products); however these benefits alone are not
sufficient to attract poor people along tropical
coastlines. Indeed, some sort of immediate improved
livelihood programme and establishment of a self
sustaining mechanism (for sustainable financial
return) can ensure society/people participation. There
is always a danger that community expectation of
receiving financial benefits might be raised too high,
thus a very careful approach is required while
providing livelihood support and developing a sus-
tainable financial return mechanism.
The success of restoration can be expressed as a
function of achieving three main objectives:
Restoration Success RSðÞ¼
Ec Sc*EnfgðÞ
where Ec is the Success in ecological engineering, Sc
the Success in society involvement, En the Success in
delivering financial and other benefits to the society.
Quantification of restoration success of a complex
system that is sensitive to ecological, socio-cultural
and economic factors is extremely difficult and
Time scale
Ecosystem integrity
Degradation curve
Mangrove restoration with
considerations of ecology ,
society and economy
Mangrove restoration
based on ecology and
society but no
considerations of economic
benefit to the community
Mangrove restoration
based on ecology only
Restoration efforts
start from here
Fig. 3 A hypothesis on the concept of mangrove restoration;
influenced by ecology, society and economy. We exemplified
three situations. (i) Restoration considered (B–D) all three
vectors and it may result a smooth upward curve. (ii)
Restoration considered (B–D
) ecology and society involve-
ment. It may result in immediate success but since there is no
consideration for financial benefit to the society (in the short
term) people will go back to their previous practices and there
will be again sharp degradation resulting in a humped shape
Gaussian curve. (iii) Restoration based on only ecology (B–D
people will take few moments to realise what is going on; this
time restoration efforts may yield positive result; very soon
people will start to work against the project which might lead
to a humped shaped curve. C reflects the status quo scenario
Wetlands Ecol Manage (2009) 17:365–383 369
requires multifaceted studies and analyses. In a
Southeast Asian context this approach is almost
impractical. Alternatively, we propose an expert
assessment scale of 0–10 (0 being unsuccessful and
10 being completely successful) to indicate the
degree of success achieved in each of the objectives
and ecosystem restoration as a whole. In this way, not
only the important factors in restoration are identi-
fied, but also their degree of success is assessed.
In our proposed framework, we differentiate
society involvement into a social issue and society
participation and an integrated function of social and
economic issues. Society involvement is a top down
approach, whereas society participation is a bottom
up approach. The maintenance of society participa-
tion depends on the level of society involvement in
different decision making processes and their eco-
nomic outcomes, i.e., the financial benefits/livelihood
improvements a society receives.
Society participation ¼
Sc EnðÞ
where Sc is the society involvement in different
decision making processes, En the economic/finan-
cial benefit to the society.
Once again, the degree of society involvement and
economic benefit to the society will determine the
success of the restoration. We can use the same
holistic expert assessment approach with a scale of
0-10 to quantify society participation.
Translating the paradigm into practice: a step
by step guideline
We translate the mangrove restoration paradigm into
a practical guideline of six major steps:
Step 1. Identify the problem area and outline the
restoration goals.
Step 2. Synthesize the past and present ecosystem
condition, especially its ecological structure
and function and societal resource depen-
dence on the ecosystem.
Step 3. Outline a systematic restoration plan (eco-
logical engineering).
Step 4. Develop a community involvement and
income subsidy plan (socio-economic
Step 5. Develop a detail implementation plan
(layout of how to implement the various
activities under different plans).
Step 6. Develop and implement a rigorous moni-
toring mechanism for logical adaptive
Identify the problem area and outline
the restoration goals
First, the geographical locations of the degraded area
need to be identified followed by the establishment of
specific goal(s) of mangrove restoration. The goals
have to be realistic (Hobbs 2007). Several questions
need to be asked before setting the goal(s): is the
mangrove restoration mainly for (i) coastal erosion
protection and land stabilization? (ii) wood/fiber
production? (iii) maintaining biological diversity
and ecological processes? or (iv) integration of some
or all of the above? Ellison (2000) reviewed the goals
of existing mangrove restoration projects and found
that out of 27 projects only two considered restoration
of ecosystem functions. Most Southeast Asian man-
grove restoration projects/programmes emphasised
tree planting alone for forest regeneration, erosion
control and coastal stabilization. However, in the true
sense of restoration, functional components of the
ecosystem must be identified and integrated in the
restoration plan.
Ecosystem synthesis: past and present
The most important step in mangrove restoration is
an analysis of past history and present conditions of
the ecosystem. A clear understanding of the pre-
disturbance state, current state and the dynamics of
the mangrove ecosystem is essential before any
intervention for restoration can take place. Three
questions need to be asked: why, when and how?
Figure 4 illustrates the need for basic knowledge of
ecology, society and economics in mangrove restora-
tion. During ecosystem synthesis, the aim of the
restoration should not be to look for a set of easy
guidelines but for a set of hard questions underpin-
ning the long-term functioning of the ecosystem.
Assessment of the existing ecosystem conditions
and its dependent community could be done either
through a scientific approach or through a participatory
370 Wetlands Ecol Manage (2009) 17:365–383
approach. For community based restoration, a partic-
ipatory method is preferred. Among the participatory
tools, participatory rural appraisal (PRA), rapid rural
appraisal (RRA), historical mapping (HM), ven
diagrams (VD), resource mapping (RM), focus group
discussions (FGD), community meeting, etc, are
effective. This stage involves exploring the condi-
tions of the ecosystem and its surrounding population
and developing an action plan. This stage helps the
community participants and the researchers and
development workers to arrive at a common under-
standing of the ecosystem functions and their
response to management and anthropogenic inter-
ventions. A common goal of the ecosystem
sustainability and meeting societal needs must be
achieved by this exercise.
Development of a systematic restoration plan
A well thought out restoration plan should be
prepared with local participation. The restoration
plan may emphasis ecological engineering based on
the findings of ecosystem assessments. In Southeast
Asian countries, most often ecological knowledge of
the pre-disturbed state is either absent or not well
documented. Therefore, we suggest three alternatives
to supplement the knowledge gaps: (i) systematic
analysis of the traditional ecological knowledge of
the communities adjoining the ecosystem, (ii) scaling
up of the ecological knowledge from another man-
grove ecosystem with similar ecological and
socio-economic influence and (iii) pilot level
The restoration plan should focus on the following.
Site selection
Site selection is critical for mangrove restoration. It is
difficult to generalise sites for successful mangrove
restoration since it depends on local environmental
factors, sociocultural context and suitability of
planting species (Kairo et al. 2001). In Southeast
Asia, mangrove restoration programmes exist in three
major types of sites: (i) mudflats, (ii) within shrimp
farms and (iii) raised lands. Shrimp farms and raised
land offer very few options for site selection but
selecting a site near a bank of running water is
encouraged (IUCN 2005). It is generally not a good
idea to target mudflats for restoration, except in cases
where these are accreting and/or where these are
formally the sites of natural mangroves. Special
considerations are required for mudflat selection
where erosion and deposition is frequent (Erftemeijer
and Lewis 2000) and ideal restoration sites must be
on the deposition site. Within the deposition site,
substrates should be stable mudflats as fresh deposi-
tions can be washed away by tidal actions before
plant establishment.
Fig. 4 Required
information before
initiation of a mangrove
restoration project/
Wetlands Ecol Manage (2009) 17:365–383 371
Site preparation
Mangrove restoration may require anywhere from a
very limited amount to a maximum level of site
preparation, depending on the specific site and
restoration objectives. For example, in a mudflat
very little or no site preparation is required (Erfte-
meijer and Lewis 2000). However, in raised land and
shrimp farms, extensive ecological engineering is
required so that the site can be inundated regularly
(Lewis and Marshall 1997). Many stable sites may
recover naturally once barriers to recovery are
removed, e.g., return of natural tidal flooding to a
fish pond, etc. Here, the very first question that needs
to be asked is why the proposed restoration sites are
not recovering naturally. Choudhury (2003) provided
detailed prescriptions for hydrological engineering in
the case of shrimp farm restoration. Lewis (2005)
provided engineering methods for raised lands.
Species selection
Species selection in mangrove restoration is an
important factor. Natural mangroves follow a dis-
tinctive zonation and during restoration; species need
to be selected following natural zonation/succession.
Depending on soil formation and hydrology, different
species may be suitable for plantation at the same
site. Choudhury (2003) developed a site-specific
species matrix for Indonesian mangroves. A similar
site-specific species list is not available for other
tropical mangroves. For example, vegetation zonation
of mangroves along the Bay of Bengal shows some
kind of uniformity and species selection for man-
grove plantation in this region adheres to this
condition. In the mangrove plantations of Bangladesh
the following site-specific species are desirable: (i) in
newly formed mudflats Sonneratia apetala is most
appropriate, (ii) newly formed sandy areas are
suitable for Avicennia officinalis, (iii) in mature/
stable lands, Excoecaria agallocha, Bruguiera gym-
norhiza and Rhizophora are the desired species.
Seedling and propagule sources
To date, mangrove restoration mostly relies on
planting. Wildings (seedlings grown in natural forests
or in the wild) and seedlings grown in nurseries are
the two major sources of seedlings. Walters (2000)
suggested that for restoration of a diverse mangrove
forest, diversity in plantation is a prerequisite.
Diversity can be obtained in two ways: planting
multiple species and creating a species mixture with
broadcasting seed. Although explicit data and refer-
ences are not available, pilot level experience from
IUCN (2005) indicates that a combination of planting
with seeding (broadcasting at a lower intensity) is a
more efficient technique than planting alone in
mudflats and raised land. The advantages of com-
bined planting and seeding over planting are that: (i)
from the very beginning a heterogeneous age class is
initiated that requires minimum gap filling and (ii) it
promotes other ecosystem services similar to those in
a natural forest.
Level of aftercare/maintenance
After-care and maintenance requirements of man-
grove plantation are site dependent. For example, in a
river bank small scale gap filling (replacing dead
seedlings with new ones) may be required, whereas in
a shrimp farm more intensive gap filling is required
since it has a limited chance of natural colonization,
compared to a river bank. Protection of the plantation
against grazing (especially buffalo) and fishermen (in
particular those who use hand-pushed catching nets)
needs to be ensured. Fishermen usually catch shrimp
larvae with fishing nets along the river banks during
high tide when planted seedlings are submerged,
causing extensive uprooting of seedlings.
Community involvement and development plan
Community development issues should be addressed
as a solution to the underlying causes of mangrove
degradation. It must ensure addressing both preven-
tive and curative measures at the same time rather
than each individually. Since there are many failure
stories, before initiating any community based resto-
ration, it is necessary to survey the choice and
preferences of the local people because they will be
the first beneficiaries but also run the risk of
becoming victims, should the project fail. Commu-
nity involvement and development plan may focus
on: (i) when and at what level the community will
participate, (ii) what are the major issues in commu-
nity livelihood and (iii) how the livelihood of
adjoining communities can be improved while
372 Wetlands Ecol Manage (2009) 17:365–383
restoration of the mangroves progresses. The plan
should specifically focus on the development of a
self-sustaining mechanism, instead of depending on
continuous financial support from the restoration
project. At the early stages of the programme,
financial support is needed, but it is desirable that
over time, a self-sustaining mechanism is developed
so that the community can sustain its livelihood and
restoration efforts when the programme is finished.
When and at what level will the community
Community participation is needed at least during
three phases: (i) ecosystem synthesis/situation analy-
sis, (ii) identification of priorities for interventions and
development of restoration strategy and action plan
and, (iii) participatory implementation and monitoring.
First, the local community can prepare a preliminary
plan of action for restoration. This plan may contain a
few priority issues that are important for the commu-
nity. Practical feasibility of the plan and the
commitment of the community can be reassessed
jointly by the project team and the community.
Simultaneously, the community and the restoration
workers may formulate hypotheses underlying the plan
and develop methods and indicators to test them and
monitor the progress and effectiveness of the plan.
How to address community livelihood issues?
Community development plans need to focus on
human well-being and strengths and limitations of
existing institutions. This plan might provide details on
specific interventions. It may also highlight particular
stress factors such as food security and provide health
services. For example, in coastal areas there is a
scarcity of drinking water that is correlated with many
water borne diseases. A variety of institutions in the
area—government, quasi-government, private sector,
community groups and development organisations
should be considered in the assessment of institutional
strengths and limitations. Issues that emerge from the
situation analysis will be prioritised and options will be
derived for future action through a trade-off analysis.
Prioritisation of issues follows the thematic integration
of mangrove restoration and human well-being. Prior-
ities will be based on socially determined trade-offs
among the problems, opportunities for the future and
the pragmatic needs to ensure successful implementa-
tion. The critical factor to sustain community
participation would be such that any intervention
should result in demonstrable positive impacts.
Implementation of plans
During implementation of mangrove restoration
activities, three points need to be considered as a
guiding principle: (i) the local community, in asso-
ciation with the technical experts, will plan the
implementation and the role of the local community
should be a positive and active one; (ii) local
communities will implement the programme and
monitoring should also be done by them. Capacity
building may be necessary for successful implemen-
tation of such a programme; (iii) a micro-level area-
specific ‘restoration and community development
plan’ should be prepared in line with the larger plan.
Monitoring, evaluation and feedback: adaptive
One of the most critical steps in a restoration programme
is the ongoing monitoring and evaluation. The moni-
toring should be based on quantifiable parameters.
Monitoring may include (i) technical (ecological)
advances of the ecosystem and (ii) societal attitudes in
support of the programme. Technical aspects can easily
be quantified, whereas quantification of the social
improvements needs relative scoring, considering the
importance of sectoral contributions to achieve the
desired goal. Technical aspects require rigorous scien-
tific monitoring, whereas social and economic aspects
can be monitored using a participatory approach. In
developing tropical countries it is not always possible to
maintain rigorous scientific monitoring because of
technical and financial constraints. Hence, a suitable
participatory monitoring system can be developed with
the aid of traditional ecological knowledge. It is
important that the outcomes of the monitoring and
evaluations are incorporated into the restoration pro-
gramme. Kolb’s (1984) experimental learning model
could aid in developing the monitoring system. The
model suggests a systematic way of learning from
experience through four major sequential steps: (i) valid
or concrete experience, (ii) reflected observations, (iii)
abstract generalisation and (iv) active experimentation.
After initial experimentation some positive experience
Wetlands Ecol Manage (2009) 17:365–383 373
can be incorporated into the cyclical process and the
cycle of learning might continue until restoration
success is achieved (Fig. 5). The uniqueness of this
model is that it will guide the restoration ecologist in a
systematic way and also will serve as a bank of
traditional ecological knowledge, which others can use
to evaluate the success of the restoration.
Example of a mangrove restoration project:
the Chokoria Sundarbans, Bangladesh
The Chokoria Sundarbans are the oldest mangrove
forests in the Indian sub-continent situated in the
delta of the Matamuhury River, Bangladesh (latitude
North and longitude 9158
East). It was a productive forest, supported high
biodiversity (Choudhury et al. 1990) and provided a
natural barrier to cyclones and storm surges. How-
ever, over the years, due to expansion of shrimp
cultivation and salt farms (as a result of a shift in
government policy (Biswas and Choudhury 2007) the
forest has been completely degraded (see Fig. 6 for
the trends of degradation). The area was characterised
by the presence of many shrimp farms and salt ponds
(Prokant and Reeves 2007). Unfortunately, in the
absence of a functional mangrove, shrimp cultivation
is not sustainable (IUCN 2005). Eventually, after a
few years of cultivation, the entire industry collapsed
due to poor ecological health and prevalence of
diseases. Today, only a handful of shrimp farms are
in operation (the number declined due to poor
economic returns). Moreover, because of the loss of
forest cover, these areas are now exposed to frequent
cyclones and tidal surges, causing loss of lives and
property. Realising the urgency of mangrove resto-
ration, at least three different initiatives were taken
by three different organizations, but these initiatives
have yet to meet with significant success. Socio-
political conflicts and challenges in ecological engi-
neering (within shrimp and salt ponds) are real
barriers for restoration in this area.
IUCN Bangladesh (IUCNB) started a pilot level
community-based mangrove restoration programme
in this area in early 2003. The goal of this programme
was to develop a community-based mangrove resto-
ration model for the entire area.
Disturbance synthesis and assessing suitability
of the ecosystem rehabilitation
IUCNB started the restoration programme with a
detailed synthesis of the degradation history (see box 1)
Concrete experience
Reflected observation
Abstract generalization
Active experimentation
If we can engage local people effectively and involve
them in such a way that they own the project then we may
get success: Awareness raising, Strengthening local
institutions, Formation of village development committee,
Formulation of village development and conservation plan,
Supporting alternative livelihood upliftment initiatives,
Promoting integrated farming etc.
Lack of people’s participation,
lack of livelihood support
and ownership is the main
cause of failure in the
restoration programmes: We
took it as a challenge
Forest and biodiversity is rapidly
decreasing, traditional
participatory approach is not
getting success
We setup different village level
committee, provided livelihood
support and conducted massive
on we suggested for expanding the
programme for the entire degraded
coastal areas of Bangladesh
awareness programme. This resulted
effective people participation and the
programme expanded successfully to
three more neighbouring villages. Later
Fig. 5 A hypothetical example of adaptive management in mangrove restoration with the aid of Kolb’s (1984) experiential learning
374 Wetlands Ecol Manage (2009) 17:365–383
Fig. 6 Satellite images
elucidate the gradual
destruction of the tree cover
and loss of the Chokoria
Sundarbans mangrove
forest over the period of
1974–2003 (modified and
reorganized from IUCN
Bangladesh 2005). Dotted
line indicates the area of
mangrove forests. Arial
coverage is explained by
inset graph
Wetlands Ecol Manage (2009) 17:365–383 375
and analysis of the present state of the ecosystem,
especially the hydrology and bio-physical conditions
of the degraded ecosystem.
Hydrology regime
The Matamuhuri river is the main source of flowing
fresh water in the area. Over the past decades a large
number of shrimp and salt farms have been formed
by constructing embankments along the banks of this
river and its tributaries. This has interrupted the
hydrology regimes, especially during normal tidal
floods in this area.
Acid sulphate soils (ASSs) are common in the coastal
wetlands and those of the Chokoria Sundarbans are no
exception. This area undergoes extensive aquaculture
during the monsoons and produces salt in the winters.
Year round soil disturbances lead to oxidation of the
pyrite and result in high concentrations of sulphuric
acid in the soil. More than 40% of the Chokoria
Sundarbans soil is predominantly ASSs (IUCN 2005).
Depending on the site, soil varies from low to
extremely high salinity (Table 1). For example, inside
the shrimp farms soil salinity is high, whereas outside
the embankment salinity is low, which is suitable for
Degradation of the Chokoria Sundarbans, Bangladesh – historical perspective
The first large scale exploitation of this forest was started during the First World War when a large
portion of this forest was chopped down for road construction. In the 1950s, local people started to
produce salt by boiling seawater with wood-fuels. In the 1960s the local inhabitants moved towards
solar energy instead of wood fuel for salt production from seawater. Thus, pressure on the forest
was reduced and the forest started to recover.
In 1970, a group of trespassers led by local elite cleared some areas of the forest land for
dwelling. Forest Department officials took legal measures against the trespassers. However, this
was the time of the liberation war of Bangladesh (1971) and it took a long time to obtain a decision
from District Sub Judge Court and through the Appellate Division. In the meantime the trespassers
continued their illegal activities of taking over the forestland. Through these processes part of the
Chokoria Sundarban (approx. 1108.04 ha went under the control of the trespassers whose
activities had destroyed the forest considerably.
In 1977, the government of Bangladesh decided to hand over some of these mangrove
lands for shrimp farming. Accordingly, an area of 228 ha of reserved forestland of Chokoria
Sundarbans was handed over to set up shrimp and duck farms. It was the first leasing efforts in the
protected area of Chokoria Sundarbans. This encouraged the local elites to establish shrimp farms
in the area. Local peoples became interested in shrimp cultivation and created political pressure to
get lease more of those lands. In 1978- 1982, further 2718 ha of the reserved forest of Chokoria
Sundarbans were transferred to Fisheries Department for shrimp culture. Though only 3205
hectares of forest land was officially leased out for shrimp farming, the farmers cut down the
surrounding areas also and included those areas under their shrimp farms since boundaries were
not clearly demarcated. Apart from this, those who had encroached gradually expand their illegal
occupancy and shrimp cultivation on the forest land. The influential people encroached the
remaining forest land by the end of 1990. Being gradually encroached, almost whole of the forest
area have been occupied by shrimp farms, human settlement and salt farms. Forest Department
has a very restricted control over the area because of intense socio-political conflicts.
At present the vegetation cover of the Chokoria Sundarbans has been stripped off
completely. A small patch of natural mangrove consisted of 17 individuals of old Sundri (
fomes) trees and some tiger ferns are alive as remnants to witness the past of the oldest mangrove
forest in Southeast Asia.
Box 1
376 Wetlands Ecol Manage (2009) 17:365–383
mangroves. Soil pH ranges from slightly acidic to
neutral indicating suitability of mangrove species.
Soil nutrient contents, especially potassium (K)
and sulphur (S) are high which helps growth of
mangrove species. Nitrogen (N) and phosphorus (P)
contents are very low, probably due to the lack of leaf
litter decomposition. Given the soil nutrient contents
of the Chokoria Sundarbans and that of the Sandar-
bans, the area is still suitable for mangroves without
any treatment, when one compares the area with that
of other mangrove forests.
The area of the Chokoria Sundarbans is characterized
by people in low to medium income groups. Very few
people are in the high income group, but they
influence the poor. The literacy rate is very low
compared to other parts of the country. Complex
socio-political conflicts are common in the coastal
areas of Bangladesh, including this area. People
adjoining the forests are suspicious of any outsiders,
even NGOs, for at least one reason: many local
people are located on encroached land and they are
always in a fear of losing control of this land.
Community organisation and social mobilisation
Given the experience from other failures in rehabilita-
tion, IUCNB emphasised community participation right
from the beginning, which helped the community to
realise its ownership of the programme. The whole
system was transparent to the community. The under-
lying assumption was that people should get organised
to work together if they are to live in close proximity and
share common interests for community development.
During the community organising process, people
from heterogeneous groups e.g. farmers, labourers,
shrimp farmers, fisherman, shrimp trader, school and
college teachers, representatives from local govern-
ments, local elites and other influential persons got
together. Participatory Rural Appraisal (PRA) tech-
niques were practiced extensively during the social
mobilisation. Community interest for restoration of
the degraded mangrove was assessed using formal
and informal interviews, community meetings and
discussions. During this process target groups were
sensitised to their own problems of declining shrimp
production and frequent exposure to natural calam-
ities, due to the absence of mangroves. Awareness
generation into the causes for the degradation of
mangroves and the need for their restoration was
carried out using focus group discussion (FGD) and
community meetings in selected villages. During this
process relevant case studies from South East Asia
were presented. Beside these, the decreasing trends of
shrimp production due to loss of mangroves were
discussed. People were briefed on historical analyses
of past natural calamities in this area such as
cyclones, draughts, massive exploitation of natural
resources, etc. At the end of this social mobilisation,
people became organised in a common motive—the
rehabilitation of the Chokoria Sundarbans.
Restoration plan
Considering the existing biophysical and socio-eco-
nomic conditions of the site, an area-specific
restoration and community development plan was
prepared with active participation of the local com-
munity. First, the community prepared a preliminary
action plan. This plan contained details of interven-
tions/activities to be undertaken. It also identified
several priority areas targeted for plantation estab-
lishment. Second, the plan was further refined
considering the necessary technical, social and eco-
nomic conditions. IUCNB guided people in terms of
technical backstopping. The purpose of the plan was
Table 1 Soil properties of the Chokoria Sundarbans
Sampling location Soil chemistry Soil nutrients
pH (±sd) Salinity
ECE (±sd) N (±sd) K (±sd) P (±sd) S (±sd)
Inside the shrimp farm 6.1 ± 0.89 22 ± 1.25 9.50 ± 1.78 0.133 ± 0.014 0.82 ± 0.16 3.06 ± 0.45 156.04 ± 2.73
Outside the shrimp farm
(River bank)
6.6 ± 0.45 12 ± 2.3 19.64 ± 1.82 0.177 ± 0.015 0.12 ± 0.12 2.57 ± 0.65 589.16 ± 3.41
Wetlands Ecol Manage (2009) 17:365–383 377
to provide a strategic framework for moving the
development toward a more sustainable path.
Restoration of degraded sites
After site selection, a plantation plan was developed
jointly by the community and the project team. The
key components of the plan are: (i) species selection,
(ii) plantation and (iii) plantation management.
Species selection
Based on the predisturbance vegetation history and
existing biophysical conditions, three mangrove spe-
cies were selected for plantation i.e., Sonneratia
apetala, Avicennia officinalis and Excoecaria agal-
locha. Both, Sonneratia apetala and Avicennia
officinalis are pioneer species in the natural man-
groves of Bangladesh (Das and Siddiqi 1985). These
species grow well on new accretions that receive
regular inundation. The community people preferred
Avicennia officinalis for plantation (since their wood
value is higher) and by matching with site character-
istics this species was planted on sandy sites. Some of
the target sites were slightly raised where Excoecaria
agallocha was planted. The regularly inundated river
banks were planted with Sonneratia apetala.
Planting was carried out during August–September.
This season is physiologically optimal for mangrove
plantation. For plantation, indigenous techniques were
used. For example, a pointed wooden pole, 3 m long
and about 10 cm in diameter, was used to make holes.
Since the soil was neither too hard nor too soft this
technique proved to be cost effective and efficient.
The planting holes were about 25-30 cm deep and
10 cm in diameter. Seedlings with well developed
taproots were manually placed in every hole up to the
collar mark of the seedlings. No manure and fertilizers
were used. Apart from the plantings, viviparous seeds
of Avicennia officinalis were also broadcast seeded to
initiate stand heterogeneity.
Plantation management
A community based approach was followed for
plantation management. For sustainable management
of the restored site, a rehabilitation and advisory
committee was formed with representations from the
community that included shrimp farmers, local
government representatives and members of the civil
society. Representatives of this community ensured
protection of the plantations and they also undertook
necessary gap fillings.
Table 2 provides a comparative summary of man-
grove restoration interventions in the area with their
initial success. The pilot initiative by IUCNB restored
21 h of degraded and newly accreted land with
Table 2 Comparative restoration parameters and initial success in the restoration of the Chokoria Sundarbans
Successive interventions
benefit to the
Leadership in
the project
Project I (Bangladesh Forest
++ - - - - + ?
Project II (Organisation for
Industrial, Spiritual and
Cultural Advancement)
+++ - + + - + +/?
Project III (Unnayan Bikolpa
Niti Gobeshona Kendra)
++--+ -?
Project IV (IUCN
+++ ++ ++ + + + +
Indicate coordinating/implementing organization. + Sign indicates positive and their frequency indicates level of considerations
(+ minimum, ++ medium, and +++ maximum). - Sign indicate absence
We assessed restoration success in terms of area planted and status of that plantation
378 Wetlands Ecol Manage (2009) 17:365–383
mangrove species and is considered a success (IUCN
2005). However, the necessary database to assess the
ecological parameters (pre- and post-restoration) was
not available to identify the ecological improvements,
except the area under plantation and the status of its
health. The programme was planned to provide
livelihood support, but due to funding limitation,
support was provided at a negligible scale (IUCN
2005). The entire activity was planned and imple-
mented on a participatory basis and involved all local
resource users and stakeholders through transparent
community-based planning, implementation and
monitoring. It should be mentioned that after the
pilot phase, there was some small scale follow up but
livelihood support was not ensured. How long the
community will keep its interest in this effort remains
to be seen.
Do we have sufficient ecological knowledge
for mangrove restoration?
Ecology, disturbance (type and patterns) and espe-
cially hydrology are the primary considerations for
mangrove restoration. Although restoration of South-
east Asian mangroves demands special attention for
social and economic issues (IUCN 2005), it cannot be
carried out without a good ecological understanding
(Ellison 2000). Documented knowledge of mangrove
ecology is very limited in Southeast Asia. Two
factors may contribute to this knowledge gap: (i)
because of a poor economy, investment opportunities
are limited and based on basic ecological research
that generates little knowledge and (ii) most of the
tropical mangrove restoration projects are funded
externally and have a limited time frame (1–5 years).
With a few exceptions, most of these short-term
projects focus on overnight solution trials rather than
investing in detailed understanding and experimen-
tation. However, these regions are extremely rich in
traditional ecological knowledge. Again, the problem
is a lack of documentation. Although limited, some
valuable evidence is available on traditional ecolog-
ical knowledge in mangrove management (Walters
1997, 2004, 2005; Dahadough-Guebas 2005a, b;
Bormthanarat et al. 2007; Jayatissa et al. 2006). Rist
and Dahadough-Guebas (2006) emphasised the use of
science and traditional ecological knowledge in
management of natural resources. This approach
creates a symbiotic relationship between local com-
munities and restoration workers. Restoration
workers benefit from ecological knowledge while
local communities benefit socially, culturally and
economically. This enhances community participa-
tion. Once properly documented, it is likely that
similar ecological knowledge can be used in other
regions for mangrove restoration, provided they
experience similar social and ecological conditions.
What determines effective community
participation in mangrove restoration?
Participation means different things to different
people. In community-based restoration projects it
is a common belief that external agencies will initiate
a restoration programme for a specific time frame to
develop a participatory mechanism and the commu-
nity will continue when the external agencies depart.
However, it is not uncommon that the whole effort
collapses as soon as the external support is with-
drawn. Although communities are often blamed for a
lack of participation, it is rare that participatory
programmes start with a thorough understanding of
the driving forces behind community participation.
The possible driving forces are: (i) cultural conditions
(ii) economic conditions (iii) ownership in the
community, (iv) transparency of the efforts and (v)
pluralism. Cultural conditions integrate the choice of
the people and restoration activities must be in line
with their traditional culture/norms. Viability of a
system will depend on the economic returns from the
system. A system may be well-designed and techni-
cally sound, but it will not be sustainable if it does not
yield any economic return to the community in the
short-term. Apart from cultural and economic con-
siderations, ownership feeling of the community and
transparency of the entire system are prerequisites for
the sustainability of a particular system. There have
to be well established linkages between the driving
forces. When a particular restoration effort is in line
with their traditional norms/cultures, produces eco-
nomic returns, the community owns the programme
and entire system is transparent to all, only then will
members of each community be accountable to their
own roles and the restoration may be successful.
Wetlands Ecol Manage (2009) 17:365–383 379
Should a mangrove restoration project put
emphasis on property right issue?
This is a very complicated issue. The short answer to
the above question is ‘yes if the intervention is
targeted at policy level but ‘no’ if it is only at the field
level restoration. Walters (1997) suggested that
restorationists should identify and negotiate with all
property right holders to reduce the likelihood of
future conflicts. Most of the river banks (where
mangroves grow), especially in Asia, are either
government or privately owned. In case of govern-
ment ownership, the local community does not have
legal access to that property. Alternatively, in private
hands, the owner might not be interested to share the
benefits with the community. It is important to assign
some kind of rights to the community so that it feels
some sort of ownership and actively participate in the
restoration programme. If the property right issue can
be sorted out at the government policy level then it
becomes easier to execute the restoration plan.
However, only field level efforts that deal with
property rights may end up with further conflicts. For
example, Primavera (2005) in her award winning
essay in Science wrote ‘as I write on this late June
afternoon, my heart grieves amid news that a young
couple,had been shot over a fishpond dispute.’
This type of situation is quite common in Southeast
Asia. In the Chokoria Sundarbans of Bangladesh
many lives have been lost in property right conflicts.
In this region hardly any evidence is available where
a mangrove restoration project deals with the prop-
erty right issue successfully. Although relevant,
considering the complexity of the issue, perhaps it
would be more productive to treat the issue of
property separately and concentrate more on effective
planning and execution of the restoration plan.
How can we measure the success of a mangrove
restoration programme?
The Society for Ecological Restoration(2004) listed
nine attributes for a restored site: (i) similar diversity
and community structure in comparison with refer-
ence sites (ii) presence of indigenous species (iii)
presence of functional groups necessary for long term
stability (iv) capacity of the physical environment to
sustain reproducing populations (v) normal function-
ing (vi) integration with the landscape (vii)
elimination of potential threats (viii) resilience to
natural disturbance and (ix) self sustainability. For
testing the success of any mangrove restoration, a
long-term monitoring programme is required. The
monitoring period needs to be even longer in a
dynamic social environment. Most frequently, suc-
cess of restoration is judged by the area under
plantation/tree cover. We maintain species diversity
or plant trees to maintain ecosystem functions. It
should be noted that depending on ecosystems of
interest and degree of disturbance, functional redun-
dancy varies. It is quite likely that the floral
assemblage of a mangrove may have a low functional
redundancy, which that raises a further concern, since
large scale mangrove restorations in Southeast Asia
continue with few species (Saenger and Siddiqi 1993)
that hardly meet the functional requirement of the
ecosystem and seldom can be considered as man-
grove restoration. Lewis (2005) suspected that this
type of restoration can hardly qualify as a successful
mangrove restoration. Interestingly, if we consider
the area under tree cover the same project may
qualify as a successful project. The potential for silent
ecological disasters remains. As such it is important
to evaluate key ecological parameters of both struc-
tural and functional components while measuring the
restoration success. Ruiz-Jaen and Aide (2005)
suggested three simple but effective measures for
assessing restoration success: (i) species diversity—
this can be measured by the presence and abundance
of species, (ii) vegetation structure—this can be
measured by vegetation cover and (iii) ecological
process—this can be measured indirectly by measur-
ing nutrient availability and biotic interactions.
Technical and financial resources are a regulating
factor for the assessment of simple to complex
functional components of an ecosystem. Depending
on available resources, one can chose from the above
mentioned parameters to monitor restoration success.
The literature on the subject has stressed the impor-
tance of mangroves for their productive, protective
and ecological functions. The necessity of the
protective function of the mangroves has been
dramatically demonstrated at the expense of hundreds
of thousands of lives during the 2004 tsunami. Hence,
380 Wetlands Ecol Manage (2009) 17:365–383
tremendous efforts continue to stop further degrada-
tion of mangroves and at the same time restoration is
carried out of degraded mangroves in a systematic
and effective way. In our restoration framework, we
structured most of the aspects. As well, we leave
many aspects (based on local conditions) for profes-
sional/personal judgments from a mangrove
restoration ecologist. A mangrove restoration team
should consist of representatives of various disci-
plines so that the full potential of the framework can
be realised.
In the first place, we emphasis social, economic
and ecological factors with special considerations for
Southeast Asia (high anthropogenic influence). How-
ever, in other parts of the world with less
anthropogenic influence, this framework can be
equally applicable after necessary amendments. For
example, where mangroves are experiencing Type II
degradation (degradation due to natural events),
social and economic considerations may be less
Second, local ecological knowledge has a high
potential use in mangrove restoration since it may act
as a symbiotic agent between a mangrove restoration
ecologist and local communities. This knowledge can
also advance the science and has the potential to
provide a new direction. It is desirable to utilise the
traditional ecological knowledge along with scientific
knowledge obtained from experimentation. Tradi-
tional knowledge can also be refined through gradual
development of scientific understanding.
Third, at the moment comprehensive measurement
of restoration success is a challenge because of the
lack of quantitative indicators. If the quantifiable
indicators are developed, it will be easier to monitor
the success or failure of a mangrove restoration
programme by using a fuzzy inference system.
Finally, we identified the lack of documentation
and research communication on mangrove ecology
and mangrove restoration, especially in the develop-
ing countries of Southeast Asia. It is important to
understand as well, that projects that fail generate no
less knowledge than the successful projects and hence
documentation of the failed projects is equally
important for the benefit of new directions to solve
the restoration puzzle.
Acknowledgements The first author (SRB) acknowledge
IUCN-The World Conservation Union, Bangladesh Country
Office where he was based for more than three and half years
and actively planned and implemented the Restoration of the
Chokoria Sundarbans programme with others. UNEP/GPA
provided financial support for the programme. Arif M Faisal
helped with the implementation of the programme and
communication with the community in the local dialect.
Bradley B. Walters, Rakibul Haque and Sayed Iftekhar
provided thoughtful comments on an earlier version of this
manuscript. We thank Tom Hazenberg for his constructive
criticism and editorial support on this manuscript. Comments
of the two anonymous reviewers and the editor were helpful in
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... Restoring forestland through a people-centered approach may thus involve balancing the diverse needs of multiple stakeholders, determining the government's institutional capacity for restoration (Erbaugh et al., 2020), and, most importantly, identifying the socio-economic determinants of the local community's willingness to participate in the restoration. Such a multifaceted complexity calls for a holistic approach to forest restoration, including balancing social, ecological, economic and institutional conditions (Biswas et al., 2009;Le et al., 2014;Brancalion and Holl, 2020). ...
... To date, most research on forest and landscape restoration in Bangladesh or its application has focused on a single or a couple of social, ecological, or institutional aspects, thereby providing only partial insights into the broader and more complex restoration challenges (Biswas et al., 2009). This is a significant hindrance to the implementation of FLR, given that it aims to improve the linkages between nature and people (Ota et al., 2020;Chazdon et al., 2020a;Fischer et al., 2021). ...
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Bangladesh government has recently pledged to restore 0.75 million hectares of degraded forest-land as part of its commitment to the Bonn challenge, however little is known about the potential challenges and opportunities towards achieving that goal. Using secondary literature complemented by expert consultation and a field survey, we examined the outcomes and limitations of the past restoration programs and identified key social, ecological and institutional aspects crucial for a successful forest restoration program in Chittagong Hill Tracts (CHT) of Bangladesh. The region accounts for over one-third of state-owned forests and supports a large part of country's forest-dwelling ethnic populations, but most forestlands are severely degraded. Our analyses revealed that past programs utilized participatory tree planting, horticulture and rubber-based agroforestry to restore degraded forestland and improve community livelihood in the CHT. However, past restoration programs merely emphasized improving tree cover without considering ecological functionality, biodiversity and carbon co-benefits of restored forests. The duration of those programs was also relatively short, without any clear plan for engaging local communities in restoration activities beyond the program period. Among others, the local ethnic community's land rights issue remains unresolved and the participant's land ownership influenced their willingness to participate effectively in restoration programs. Households with secured land rights had a more positive attitude towards participating in forestland restoration than those with unsecured land rights. Suitable acts and policies that may allow people to legally continue tree-based land use in the regions (i.e., forest and land tenure rights) are also lacking. Future forest and landscape restoration (FLR) programs may thus need to focus on improving restored forests' biodiversity and ecological functionality, resolving the local people's forest and land tenure rights, and involving them with site-specific restoration interventions. The engagement of local and regional level multiple stakeholders in an FLR program is also essential for realizing the restoration's multiple social and ecological benefits.
... Mangrove communities are of great importance in the positions they occupy, as they are environmentally important, as they contribute to biodiversity by being a safe environment for a large number of living organisms that complement marine food chains (Kholeif,2007), and provide the marine food web with a number of elements necessary to enrich it. (Biswas et al. 2009) In addition to being considered an important habitats for nesting migratory birds, or considered important stations in the path of movement and migration of birds, (Khalil, 2004) it also has a geomorphological importance for beaches, and represent walls against waves and sea currents in periods of severe storms, thus protect them from exposure to marine erosion. ( Massel, 2006) Also, mangrove forests have economic importance for the quality of wood and its use in the manufacture of home furniture, (Kumar, A. et al., 2010) . ...
... Although the study was limited to revealing the causes of mangrove deterioration related to geomorphological changes, field observations revealed other reasons for mangrove deterioration, such as the pollution of the coastal environment with solid waste and the spread of green algae and other reasons that need further study. Therefore, the study proposes a number of recommendations in the light of its discussions and results -Tarut Bay is unique in that it is of great environmental value, as the United Nations Environment Program classifies it in category V and VI, and there are many geomorphological sites suitable for mangrove propagation, which are shown in Figure ( 3,4,5), where the shallow lands adjacent to the coasts of the island and the bay can be used to establish large-scale mangrove farms These farms simulate the ecological mangrove park, which is located on the northwestern and northeastern coast of Tarut Bay, which was designed by Aramco, as a kind of social responsibility towards the local community in which it operates. This experience can be generalized with companies operating in the region to add new areas of mangroves to enrich life environment in the region. ...
... A minimum width or area is required to sustain mangroves, to maintain species richness, and to support the provision of ecosystem services (Duke et al. 2007;Ilman et al. 2011;McIvor et al. 2012). There is controversy as to whether urban and aquacultural areas can be restored to mangroves (Giri et al. 2008;Biswas et al. 2009;van Oudenhoven et al. 2015), and if a suitable area is not fully secured, mangroves may not exert tidal attenuation function (Takagi 2017). Locations of restored mangroves are critical for disaster reduction. ...
... To promote their participation, benefits, including the assignment of some rights, such as mangrove ownership(Biswas et al. 2009), financial payment for participation(Karminarsih 2007;Sasongko et al. 2014), and reflection of their opinion in rehabilitation programs(Padawangi 2012;Dalimunthe 2018;Martínez-Espinosa et al. 2020), should be emphasized more. ...
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Giant seawalls have been constructed in areas stricken by the 2011 Great East Japan Earthquake to protect nearby townships from tsunamis, but their construction has caused great controversy. This study conducted a survey using the best–worst scaling (BWS) method in Iwate and Miyagi Prefectures, where the seawalls are constructed to understand what specific factors citizens think should be taken into consideration during construction. The results revealed that the negative impacts on the natural environment and seawall height (safety) were ranked most highly. Additionally, the results of regression analysis with respondents’ B-W scores for the negative impacts on the natural environment and seawall height (safety) as the explained variables demonstrated that people who less strongly recognized the need for a seawall were more likely to think the negative impact on the natural environment should be taken into consideration than did people who strongly recognized the need for a seawall; however, people who did not know much about seawalls were more likely to think seawall height should be considered than people who did. The regression analysis also found that people who more strongly felt there was a need to build seawalls were more likely to think seawall height should be a key consideration, whereas people who personally had suffered harm in the tsunami following the Great East Japan Earthquake were more likely to think seawall height should be a key consideration than did those who were not personally affected.
... A minimum width or area is required to sustain mangroves, to maintain species richness, and to support the provision of ecosystem services (Duke et al. 2007;Ilman et al. 2011;McIvor et al. 2012). There is controversy as to whether urban and aquacultural areas can be restored to mangroves (Giri et al. 2008;Biswas et al. 2009;van Oudenhoven et al. 2015), and if a suitable area is not fully secured, mangroves may not exert tidal attenuation function (Takagi 2017). Locations of restored mangroves are critical for disaster reduction. ...
... To promote their participation, benefits, including the assignment of some rights, such as mangrove ownership(Biswas et al. 2009), financial payment for participation(Karminarsih 2007;Sasongko et al. 2014), and reflection of their opinion in rehabilitation programs(Padawangi 2012;Dalimunthe 2018;Martínez-Espinosa et al. 2020), should be emphasized more. ...
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Flood control basins (FCBs) are artificially constructed facilities with the potential to conserve the biodiversity of floodplain ecosystems. However, the intensity of disturbance in FCBs is generally lower than that in natural floodplains; thus, habitats for plants with disturbance-dependent life histories and for animals that use temporary waters or mudflats can be lost in the years following FCB construction. Here, the Asahata FCB in Shizuoka city, Japan, was studied as an example, where the species diversity of wetland plants has been conserved as a result of diverse activities. Although most activities had objectives other than biodiversity conservation, they contributed to conserving plant diversity and providing habitats for endangered plants. The FCB is a green infrastructure that not only enables flood control but also supports activities for various purposes. Additionally, its proper use contributes to biodiversity conservation.
... Forests 2023, 14, 158 ...
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Evaluation of Plant Growth and Potential of Carbon Storage in the Restored Abstract: Mangrove forest in Lubuk Kertang Village, West Brandan sub-district has been converted around 20 ha annually (1996-2016) into various non-forest land use. Rehabilitation can be a solution to restore the condition of the ecosystem so that it can resume its ecological and economic functions. This paper discusses the evaluation of mangrove rehabilitation carried out by planting 6000 propagules in December 2015 and 5000 seedlings in May 2016 with Rhizophora apiculata species in abandoned ponds. Monitoring was carried out every 6 months from 2016 to 2022. In the restored area, 11 true mangrove species and 3 associated mangrove species were found. The percentage of plants that survived after seven years was 69.42% for planting using propagules and 86.38% for planting with seedlings. The total biomass carbon stocks stored by 7-year-old plants using propagules was 51.18 Mg ha −1 , while the carbon stored by planting using seedlings was 56.79 Mg ha −1. Soil carbon stocks at the planted site with propagules were 506.89 ± 250.74 MgC ha −1 , and at the planted site with seedlings were 461.85 ± 102.23 MgC ha −1. The total ecosystem carbon stocks (including aboveground carbon) in the planted site using propagules were 558.07 MgC ha −1 , while planting using seedlings were 518.64 MgC ha −1. The dataset and findings on the carbon storage evaluation of mangrove rehabilitation will be useful for blue carbon research community and policymakers in the context of the climate change mitigation strategy for Indonesia.
... The first steps of a restoration programme should be directed toward the identification of the environmental stressors and potential threats to restoration sites 27,108,109 . In Sundarban many past replantation programmes have failed due to a lack of proper knowledge, research communication, and documentation on mangrove ecology [110][111][112] . Thus, the present study recommended a holistic mangrove restoration plan by bridging ecology, society, and economics. ...
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Mangrove forests being the abode of diverse fauna and flora are vital for healthy coastal ecosystems. These forests act as a carbon sequester and protection shield against floods, storms, and cyclones. The mangroves of the Sundarban Biosphere Reserve (SBR), being one of the most dynamic and productive ecosystems in the world are in constant degradation. Hence, habitat suitability assessment of mangrove species is of paramount significance for its restoration and ecological benefits. The study aims to assess and prioritize restoration targets for 18 true mangrove species using 10 machine-learning algorithm-based habitat suitability models in the SBR. We identified the degraded mangrove areas between 1975 and 2020 by using Landsat images and field verification. The reserve was divided into 5609 grids using 1 km gird size for understanding the nature of mangrove degradation and collection of species occurrence data. A total of 36 parameters covering physical, environmental, soil, water, bio-climatic and disturbance aspects were chosen for habitat suitability assessment. Niche overlay function and grid-based habitat suitability classes were used to identify the species-based restoration prioritize grids. Habitat suitability analysis revealed that nearly half of the grids are highly suitable for mangrove habitat in the Reserve. Restoration within highly suitable mangrove grids could be achieved in the areas covered with less than 75 percent mangroves and lesser anthropogenic disturbance. The study calls for devising effective management strategies for monitoring and conserving the degraded mangrove cover. Monitoring and effective management strategies can help in maintaining and conserving the degraded mangrove cover. The model proves to be useful for assessing site suitability for restoring mangroves. The other geographical regions interested in assessing habitat suitability and prioritizing the restoration of mangroves may find the methodology adopted in this study effective.
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Without action, global impacts from natural hazards are expected to increase in frequency and severity due to climate change and concurrent ecological and social crises. Nature-based solutions (NbS) are sustainable approaches to disaster risk reduction (DRR) that provide multiple additional benefits for nature and to a range of stakeholders. NbS contrast with ‘grey’ infrastructure measures, which rely on non-natural materials, generally aim to address a single issue, and have fewer societal co-benefits. NbS are generally conceptualized as ‘green’ measures, although ‘hybrid’ measures (combining green and grey) are also NbS. DRR measures often rely on public and community buy-in for their success, but NbS amplify this reliance with their emphasis on co-creation, -implementation, and -monitoring. Public acceptance is therefore directly linked to the ability of NbS to provide benefits, including DRR. Although NbS research increasingly focuses on barriers to its uptake, there is a lack of research on public acceptance of local residents in NbS ‘host communities’. Instead, it is often taken for granted that current high levels of public acceptance of NbS at European scale will be replicated at local levels and maintained over time. Additionally, there is a lack of past research that compares perceptions of NbS and grey measures, explores a broad range of factors that may influence public acceptance, and determines preferences across the full green-hybrid-grey spectrum. This research, conducted within the Horizon 2020 OPERANDUM project, aims to determine factors that contribute to positive or negative attitudes and behaviours towards NbS for DRR. A systematic literature review was carried out, followed by citizen surveys and focus groups at planned European NbS sites. Surveys were conducted in Scotland (landslides; n=66 respondents), Finland (lake eutrophication; n=204) and Greece (flooding; n=84), followed by in-depth focus groups (n=4) at the Scotland site. Results from the three methods noted above show generally high public acceptance, but also consistently highlight scepticism regarding NbS effectiveness for DRR and uncertainty surrounding the approach as barriers to acceptance. Dozens of factors that can influence acceptance were identified and, despite variation in the strength of factors across study sites, several consistencies emerged. For example, public trust in implementers was important for positive attitudes towards the NbS, while perceptions of place were important for pro-NbS behaviour (i.e., engagement). Cultural ecosystem services, and especially aesthetic value, were highlighted as crucial determinants of acceptance throughout. However, in the Scotland site, the effectiveness of the NbS for reducing risk was paramount and therefore the perceived limitations of NbS drove preferences towards greyer (i.e., more hybrid) measures. This thesis emphasises a need for more focus on the importance of meeting public expectations for risk reduction, providing cultural ecosystem services as co-benefits, centering people-place relations in NbS work, and considering the efficacy and support of hybrid rather than purely green options. Additionally, the Public Acceptance of NbS framework [PA-NbS] is introduced in the review as a starting point for NbS researchers and practitioners to systematise their consideration of public acceptance and how it can be increased. It includes overarching recommendations: provide benefits, increase awareness of benefits, communicate effectively, and promote participation. Each recommendation has four corresponding success criteria which, through the subsequent analyses, are tailored to both the specific contexts of the study sites and for NbS projects globally. Using interdisciplinary concepts and a mixed-methods approach, this research takes a critical perspective with the practice-oriented aim of improving the sustainable success of NbS for DRR. With this, further research is called for to better understand public expectations of NbS, how best to frame NbS and their (co-)benefits to different stakeholders, and how acceptance may change through time based on evidence of NbS performance.
Mangroves are forested wetlands of intertidal tropical regions. They grow on fringing and riverine shorelines and, like tidal marshes, build land and provide shoreline protection. They are refugia for finfish and shellfish and, in developing regions, provide food, timber, and fuel to local communities. In the Paleotropics, there are many mangrove species, whereas, in the Neotropics, mangrove forests are less diverse. Much mangrove habitat has been lost to forestry, conversion to aquaculture, and coastal development. Large-scale afforestation projects have been undertaken in Southeast Asia, Indonesia, and islands of the western Pacific. Restoration involves planting easy-to-propagate species such as Rhizophora and sometimes natural recruitment when a source of dispersing propagules is nearby. Many projects fail, however, because of planting at elevations too low in the tidal frame, on high-energy shorelines, or harvesting of planted trees. Because they are large and long-lived, mangrove forest ecosystem development proceeds more slowly than tidal marshes. 25–50 years may elapse before they provide levels of structure and function found in mature forests. In the developing world, successful restoration of mangrove forests depends not only on the restoration effort but on stewardship of the resource to produce timber and food for the local community.
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Tsunamis, storm surges, flooding, and erosion pose serious threats to the world's coastal systems, particularly in the tropics. These immediate threats have been accelerated by both natural and man-made factors. The majority of countries have responded to these threats with severe protective measures, exacerbating existing ecosystem problems. To combat this threat, there is an immediate need for sustainable coastal protection measures. Vegetation Bioshields are one such measure to achieve this. This review examines the current state of vegetation bioshields in South Asia, the benefits and drawbacks of their use, and future prospects. Case studies from India and Sri Lanka are used to illustrate the current state of vegetation bioshields. The majority of vegetation bioshield projects were constructed in the aftermath of the 2004 Indian Ocean tsunami with inadequate design, maintenance, and follow-up, resulting in an extremely low success rate. Additionally, community participation is limited in a number of vegetation bioshield planting campaigns. A viable alternative to hard structures is the concept of hybrid structures, which combine hard structures with natural ecosystems such as vegetation. A comprehensive inventory of indigenous species and policy changes aimed at their conservation and management are urgently needed. Simultaneously, strict enforcement of environmental laws is required.
Mangroves are trees or bushes growing between the level of high water of spring tides and a level close to but above mean sea-level. Very few species of mangrove are deep rooted, or have persistent tap roots. Almost all are shallow rooted but the root systems are often extensive and may cover a wide area. Rhizophoraceous trees have seedlings with a long radicle which would seem well suited to develop into a tap root, but as soon as the seedling becomes established in the mud the radicle develops little further. Trees of Avicennia and of Sonneratia develop several different kinds of roots. The main rooting system consists of large cable roots which give off anchoring roots downwards and aerial roots or pneumatophores upwards. These pneumatophores in their turn produce a large number of nutritive roots which penetrate the mineral-rich subsurface layers of the soil. The land animals found in mangrove forests include roosting flocks of fruit bats, fishing and insectivorous birds, and many insects are conspicuous. Of the marine animals, crabs and molluscs live permanently in the forest, and prawns and fishes come in on the tide to feed on the apparently abundant nutriment provided by the mangrove soils. In South East Asia man uses mangrove areas for the establishment of ponds for the culture of fish and prawns, and for timber.
The present investigation quantifies the biodiversity of the Brachyura and fish living within the natural mangrove Avicennia marina, salt marsh and replanted mangal, and compares relevant features of the abiotic and biotic environments of these habitats. Measurements of sediment organic matter, grain size, soil water pH and the moisture content indicate that the natural mangrove areas have lowest mean grain size, pH, and highest organic and moisture contents. Planted mangrove areas have a higher mean grain size and slightly higher pH, but lower organic and moisture contents. Differences occur between brachyurans in planted and natural mangrove areas, but the biodiversity was similar between salt marsh and natural mangrove areas. Nasima dotilliformis was the only crab which did not occur at all planted mangrove sites, while Serenella leachii was missing from natural mangrove. Juvenile fish species enter mangroves, using these as nursery grounds, and quantitative sampling indicates that mangrove areas, especially pneumatophores, form a special habitat for these small fish.