Ecological Restoration: Techniques and Challenges

1. 靜宜大學 生態研究所 碩士班 自然保育學Restoration ecology 鄭先祐(Ayo) 國立 臺南大學 環境與生態學院 生態科學與技術學系 教授 Japalura@hotmail.com

2. 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).

3. Contents • Ecological restoration • Animal reintroduction • Restoration in marine environments • Environmental regulations that drive restoration practice • Concluding thoughts

4. 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.

5. Fig. 15.1 the trajectory of a restoration project may be viewed in terms of ecosystem structure and processes. (Bradshaw, 1984)

6. Restoration is an iterative process that includes • Examining preexisting, historic, and current reference conditions prior to designing the restoration plan. • Developing a restoration design or plan • Obtaining the necessary permits, where relevant to perform the work • Implementing the design, which can include modifications to soil, hydrology, and plant and animal communities as appropriate. • Monitoring of the restored site

7. 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.

8. 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.

9. 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.

10. A flowchart of the decisions made in designing and carrying out an ecological restoration project. (Fig. 15.2) • Determine restoration goal (restore what?) • Identify constraints (physical, biochemical feedbacks, trophic-level interactions, species pool, landscape, environmental changes) • Prioritize constraints • Address constraints • Characterize changed system • Maintain the system

11. Steps in designing and implementing ecological restorations • 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： • 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.

12. Restoration challenges • Lack of knowledge • Scale issues in restoration • Implementation in practice

13. Lack 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.

14. 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 self-sustaining 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. 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 an experimental approach and to allow long-term data collection, ecological restoration offers unique opportunities to add to our scientific knowledge while increasing ecosystem functioning.

17. Animal reintroduction • Well-justified reintroduction objectives include (IUCN) • Enhancing the long-term survival of a species • Reestablishing a keystone species • Providing long term economic benefits to the local and/or national economy.

18. Guidelines designed to maximize success • 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. • 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. • Identify and evaluate suitability of stock to be reintroduced, including genetic factors. • Evaluate social, political, and economic conditions at the reintroduction site to ensure that long-tem financial and political support will be available.

19. 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. • Post-release monitoring should be done using an adaptive model, ensuring that necessary intervention can be carried out.

20. 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？

21. 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.

22. Regulations in the United States • Clean water act (CWA), 1972 • Endangered species act (ESA), 1973 • Surface mining control and reclamation act (SMCRA), 1977

23. 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.

24. 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.

25. 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.

26. 問題與討論 Japalura@hotmail.com • Ayo 台南 NUTN 站http://myweb.nutn.edu.tw/~hycheng/