Transcript 15 Restoration of damaged ecosystems and endangered population

Restoration of damaged
ecosystems and endangered
population
鄭先祐(Ayo)
國立台南大學 環境與生態學院 教授
[email protected]
Introduction
 Given th extensive damage already
caused by human activities, many
scientists and practitioners turn to
restoration as the primary means to
conserve biodiversity.
 Meaningful execution requires some
measure of tenacity(堅毅), clairvoyance
(千里眼) , and dumb luck(運氣).
2
Contents
Ecological restoration
Animal reintroduction
Restoration in marine environments
Environmental regulations that drive
restoration practice
 Concluding thoughts




3
Supplements I
 Essay 15.1 the happy eagle conservation
program: research, conservation, and
community-based education to save the
national bird of Panama
 Essay 15.2 achieving success in Mine
reclamation: an example from semiarid
lands in western Australia
 Box 15.1 Genetic considerations in
reintroduction
 Box 15.2 other pertinent US legislation
requiring restoration activities
4
Supplements II
 Case study 15.1 restoring the nation’s
wetlands: why, where, and how?
 Case study 15.2 temperate riverine
ecosystem restoration: the North creek
floodplain
 Case study 15.3 from Kenya to Costa Rica:
solutions for restoring tropical forests
 Case study 15.4 restoration of an endangered
species: the black-footed ferret
 Case study 15.5 in the eye of the hurricane:
efforts to save the Puerto Rican parrot(鸚鵡).
5
Ecological restoration
 Aldo Leopold initiated plant community restoration at
the University of Wisconsin Arboretum during the
1930s.
 Leopold and his colleagues restored approximately
120ha of forest and mixed-grass prairie, primarily
through manipulating ecosystem processes first, and
vegetative structure second.
 Today restoration ecology draws on all major
disciplines and sub-disciplines of the natural sciences,
including ecosystem and landscape ecology,
geomorphology, hydrology, soil science, geochemistry,
animal behavior, theoretical ecology, population
biology, invasion biology, and evolutionary ecology.
6
Fig. 15.1 the trajectory of a restoration project
may be viewed in terms of ecosystem
structure and processes. (Bradshaw, 1984)
7
Restoration is an iterative process
that includes
1. Examining preexisting, historic, and
current reference conditions prior to
designing the restoration plan.
2. Developing a restoration design or plan
3. Obtaining the necessary permits, where
relevant to perform the work
4. Implementing the design, which can
include modifications to soil, hydrology, and
plant and animal communities as
appropriate.
5. Monitoring of the restored site
8
Restoration
 enhancement, reclamation, re-creation,
rehabilitation, remediation, augmentation,
and translocation.
 Rehabilitate or restore plant
communities, animal “restoration” usually
is undertaken only for species that are
highly endangered, typically through
intensive ex situ breeding
reintroduction and translocation
programs.
9
Role of restoration ecology in conservation
 Restoration ecology is a young and controversial (爭
議性的) discipline.
 Restoration ecology offers the opportunity to conduct
experiments that provide insights into important
basic biological questions, such as community
assembly dynamics, secondary succession, fire cycles,
the role of keystone species, and the nature of
invasibility of ecosystems.
 Insights from this type of research can be invaluable
for the management of natural areas, address issues
such as controlling nonnative species invasions,
reintroducing keystone species such as large
predators, and restoring natural disturbance regimes
such as fire cycles or flooding.
10
 A serious concern regarding ecological
restoration is its effect on the regulation of
ecosystem conversion for human purposes.
 However, pro-development forces increasingly
do view ecological restoration as an alternative
on in situ conservation.
 The ecological restoration and conservation are
complementary parts of an overall ecosystem
protection and management strategy.
 Critically, ecological restoration should never
be seen as a substitute for protection of
intact ecosystems.
11
A flowchart of the decisions made in
designing and carrying out an ecological
restoration project. (Fig. 15.2)
1. Determine restoration goal (restore what?)
2. Identify constraints (physical, biochemical
feedbacks, trophic-level interactions,
species pool, landscape, environmental
changes)
3. Prioritize constraints
4. Address constraints
5. Characterize changed system
6. Maintain the system
12
Steps in designing and implementing
ecological restorations
1.
2.
3.
4.
Site assessment：背景資料、包括：pollen cores, historical
accounts, survey records, and old photographs
Setting goals：目標取向？限制？
Design：multidisciplinary approach
Implementation：


5.
when possible, local community members should be
included in implementation.
Maintaining control groups and applying treatments to
portions of the restoration site allow for adaptive
management and for statistical analysis of restoration
outcomes.
Monitoring and adaptive management

Long-term monitoring is vital to guide the adaptive
management of the restored site.
13
Restoration challenges
 Lack of knowledge
 Scale issues in restoration
 Implementation in practice
14
Lace of knowledge
 Much more information is available on birds and
mammals than on bacterial communities across the
globe, yet the success of a project may be dependent
on appropriate soil bacteria being present.
 We know that animals often play key roles in
structuring ecosystems. However, the majority of
restoration efforts are focused on plant communities.
 In many cases, a “bottom-up” approach may be the
most effective– that is, once essential ecosystem
components, such as soil structure and geochemistry,
hydrological functions, and vegetative structure are
restored, animal communities may assemble
themselves. However, suitable habitat does not by
itself guarantee the presence and viability of specific
animal populations.
15
Scale issues in restoration
 Restoration projects that focus on a small
scale may succeed in establishing native
ecological systems in the short term, but
may fail in the longer term because the
large ecological context required to allow
these restoration efforts to be selfsustaining is either not present, too
degraded, or operating at too small a scale.
 When ecosystem degradation has been
extremely intense or of great spatial extent,
restoration can be particularly difficult to
achieve (Fig. 15.7)
16
17
Implementation in practice
 Many restoration projects do not use a
multidisciplinary approach.
 Instead, they focus more narrowly on a
single taxon or a single ecosystem function.
 Restorations not only make use of scientific
knowledge, but add to it as well.
 When resources are available to support
and experimental approach and to allow
long-term data collection, ecological
restoration offers unique opportunities to
add to our scientific knowledge while
increasing ecosystem functioning.
18
Animal reintroduction
 Well-justified reintroduction
objectives include (IUCN)
1. Enhancing the long-term survival of a
species
2. Reestablishing a keystone species
3. Providing long term economic benefits to
the local and/or national economy.
19
Guidelines designed to maximize
success
1. Conduct a feasibility study, including assessment of
the biology of the species, availability of individuals of
the same taxonomic status for reintroduction, and
whether other species have taken up the ecological
role of the species that has been extirpated from the
wild.
2. Select and evaluate sites within the historic range of
the species, ensuring that suitable habitat is available
that is not subject to the same threats.
3. Identify and evaluate suitability of stock to be
reintroduced, including genetic factors.
4. Evaluate social, political, and economic conditions at
the reintroduction site to ensure that long-tem
financial and political support will be available.
20
5. Plan a properly financed reintroduction with
approval by all stakeholders, and in
coordination with management agencies.
Design pre- and post-release monitoring to
make the reintroduction a carefully
designed experiment, with the capability to
test methodology, thereby allowing
improvements for future releases.
6. Post-release monitoring should be done
using an adaptive model, ensuring that
necessary intervention can be carried out.
21
Restoration in marine environments
 Marine restoration activities are
widespread, particularly where
restoration enhances commercially
important fisheries.
 Reforestation projects to restore
mangrove ecosystems, areas cleared for
shrimp ponds and other fisheries.
 人工魚礁
 Still in the trial-and-error stage.
 2004, December 26, 海嘯之後，如何復育？
22
Environmental regulations that
drive restoration practice
 The financial burden of restoration is
significant, with the total cost of a
typical restoration project in the US
mounting to as much as US$3.00 per
square foot, or over US$130,000 per
acre.
 Such expense renders even small-scale
ecosystem restoration projects
problematic.
23
Regulations in the United States
 Clean water act (CWA), 1972
 Endangered species act (ESA), 1973
 Surface mining control and
reclamation act (SMCRA), 1977
24
International regulations
 Many countries share common elements in
their restoration-related legislation.
 For example, mining regulations require
reclamation of degraded lands in Chang, India,
and Canada
 Convention on Biological diversity.
 Restore degraded ecosystems and threatened
species, with particular emphasis on forests,
inland waters, and marine ecosystems, including
coral reef.
25
Concluding thoughts
 1970s, to restore ecosystem were based not on good
science or bad science, but on no science at all.
 1980s, many restoration efforts involve simply the
replanting of native nursery stock.
 1990s, working in interdisciplinary teams with diverse
backgrounds and objectives, restoration ecology was
more “ ad hot” or “compromise” ecology than a science
based primarily on sound ecological principles.
 2000s, experimentation and adaptive management of
restoration projects.
 Programs that are devoted to the training of
ecosystem restorationists.
 There is still plenty of basic science to come by to
advance the field.
26
 Increasingly, restoration may become a vital
component of conservation practice, as we seek to
improve degraded habitats.
 Coupling restoration efforts to larger conservation
efforts may offer many opportunities.
 Because restoration is itself a long-term process, it
forces us to consider how we might influence
biodiversity conservation over longer time scales.
 One of the greatest needs for future work in
restoration as a conservation tool is to increase our
capacity to learn from restoration efforts, via
comparative analyses and experimental approaches.
27
Supplements II
 Case study 15.1 restoring the nation’s
wetlands: why, where, and how?
 Case study 15.2 temperate riverine
ecosystem restoration: the North creek
floodplain
 Case study 15.3 from Kenya to Costa Rica:
solutions for restoring tropical forests
 Case study 15.4 restoration of an endangered
species: the black-footed ferret
 Case study 15.5 in the eye of the hurricane:
efforts to save the Puerto Rican parrot(鸚鵡).
28
問題與討論
Ayo NUTN 站 http://mail.nutn.edu.tw/~hycheng
_/_/_/_/_/_/_/_/_/_/_/_/ since 2006_/_/_/_/_/
29