Ch. 15-Restoration Ecology

Transcription

1 Ch. 15-Restoration Ecology Conservation focuses on protecting and maintaining diversity and ecological processes Restoration emphasizes active management to bring back a former state of an ecosystem ( to make almost as good as new ) Conservation is the objective; Restoration is an example of a method, one way of accomplishing that goal.

2 Ecological Restoration The process of intentionally altering a site to establish a defined, indigenous, historic ecosystem The goal of this process is to emulate the structure, function, diversity and dynamics of the specified ecosystem Society for Ecological Restoration

3 Ecological restoration is an iterative process that includes 1. Examining reference (historic) conditions 2. Developing a restoration plan 3. Obtaining permits 4. Implementing the design (modifying soils, hydrology, plants, animals, etc.) 5. Monitoring restored site

4 Fig A flowchart of the decisions made in designing and carrying out an ecological restoration project

5 Other common terms Revegetation: Re-establishment of some sort of vegetative cover, not necessarily the original vegetation. Rehabilitation: Aesthetically enhancing a site to make it look like its former condition. Reclamation: Restoration of the functions but not necessarily the components and structure. Re-creation: Reconstruct an ecosystem to an historic condition that might not be the undisturbed reference condition. Ecological Recovery: Hands-off approach to let the system regain desirable attributes. Ecological Engineering: Design, construct and monitor ecosystems for the benefit of humans and nature. Ecological Restoration: Return a degraded system to its undisturbed historic state (with sustainable function and structure).

6 Fig The trajectory of a restoration project in terms of ecosystem structure (species richness and complexity of interactions) and processes (primary productivity, nutrient cycling). [after Bradshaw, 1984]

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9 FISH TISSUE SAMPLING EVENTS

10 SEDIMENT SAMPLING EVENTS

11 Ottawa River, Ohio Authorized Legacy Act Project Site

12 Restoration Challenges Likelihood a site can truly be restored natural modified Condition of the neighborhood

13 Restoration Challenges Lack of knowledge

14 Potential pathways by which displacement of native plant species by exotic plants can cause shifts in soil community composition and function. Several direct pathways: differences in the quantity or quality of (1) litter production or (2) root exudates, altering resource availability for belowground communities (3) release of novel chemicals with antimicrobial activities (4) novel nutrient acquisition strategies such as N fixation that change biogeochemical processes (5) differences in the local soil environment induced by changes in root architecture or function. Wolfe and Klironomos (BioScience 2005). These direct mechanisms may lead to indirect effects, such as changes in disturbance regimes, including fire (1a).

15 Restoration Challenges Lack of knowledge Issues of scale Implementation in practice

16 The Winous Point marshes near Port Clinton (Ohio) 130 years ago (left, digitized from detailed hand-drawn maps) and the way they appear today (right, Landsat- 7 true color image, 1999). Protection of property and preservation of habitat for waterfowl and wildlife has required widespread use of dikes and water control structures throughout the coastal areas of western Lake Erie and elsewhere.

17 Winous Point Horseshoe Marsh

18 Mar Apr May Jun Jul Aug Sep Oct Nov Dec Water level in open wetland Water level in diked wetland Feb Jan Water level

19 Trumpeter swans (Cygnus buccinator)

20 Restoration has only recently gained attention because Conservationists have been preoccupied with identifying and protecting natural areas. Restored systems are thought to be inferior. True restoration of ecosystems is not possible. Restoration might be used to weaken arguments for conservation.

21 Restoration ecology is now a growing discipline, because Advances in research in restoration ecology (see book and field trips). Success stories. Massive ecological destruction (forests, wetlands) makes restoration necessary. Legislation requiring restoration, mitigation, rehabilitation, etc. ( legal ecology )

22 Some selected titles of recent papers in Conservation Biology Greening the U.S. Constitution Legal Ecology: Ecosystem Function and the Law Conservation Science, Biodiversity, and the 2005 U.S. Forest Service Regulations Ecosystem services and the law A Multidisciplinary Approach to Assessing the Sustainability of Freshwater Crayfish Harvesting in Madagascar Coffee and Conservation: a Global Context and the Value of Farmer Involvement Where Conservation Biology and Conservation Ballistics Meet Ecological Ethics: Building a New Tool Kit for Ecologists and Biodiversity Managers

23 Endangered Species Act (1973) One of the drivers of restoration (see book Ch 15) Conservation and protection of threatened and endangered species and the habitats in which they are found. Endangered species: in danger of extinction throughout all or a significant portion of its range Threatened species: likely to become an endangered species in the foreseeable future Designated critical habitat: land or water of special significance to the listed species survival.

24 Yellowstone NP early winter wolf population

25 International conservation laws Environmental protection, management, and conservation are not bounded by national borders. Hundreds of legal instruments that focus on international environmental and conservation issues. Problems surrounding global cooperation in conservation equitability economic realities need for incentives need for a leader country many diversity threats occur across international boundaries (particularly in the tropics where economic stress is more severe and environmental regulation, management and enforcement are lacking).

26 The Ramsar Convention on Wetlands (1971) The 159 Contracting Parties to the Ramsar Convention on Wetlands (shaded green) 1. Conduct land-use planning for wetland preservation. 2. Designate and protect at least one wetland in their country as a Wetland of International Importance. 3. Establish wetland reserves

27 Some procedures and examples of ecological restoration Soil restoration Grassland restoration Forest restoration Aquatic ecosystem restoration

28 Restoring terrestrial systems Soil restoration

29 Windbreaks Terracing

30 Conservation tillage system that leaves at least 30 percent of the soil covered after planting with last year's crop residue (Central Iowa). Source: NRCS-USDA

31 Bioremediation of contaminated sites

32 Phytoremediation of contaminated soils

33 Restoring terrestrial systems Grassland restoration

34 Forest restoration and management Contour stripcropping and managed forests in Iowa save soil on highly erodible land. Managed woodland in South Carolina Source: NRCS

35 Controlled burns Herbivore exclusion

36 Restoring aquatic systems Re-establishing hydrological characteristics Reducing anthropogenic delivery of sediments and contaminants Revegetation with native species/removal of exotic species

37 Kissimmee River (FL)

38 Kissimmee River Restoration

39 Restoration Principles Identify key processes that stress the system. Determine realistic goals and measures of success. Use methods that have produced success elsewhere. Monitor effectiveness.

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41 Case: Western Lake Erie stresses Physical restructuring: wetlands drainage, regulation of flows, damming of rivers, dredging of harbors, etc. Pollution: sewage, industrial discharges, agricultural runoff. Overharvesting: depletion of stocks of commercial fish. Introduction of exotics: lamprey, alewife, smelt, zebra mussels, Asian carp, round goby, etc.

42 Restoration Principles Identify key processes that stress the system. Determine realistic goals and measures of success. Use methods that have produced success elsewhere. Monitor effectiveness.

43 What is a realistic restoration goal for Lake Erie? Do we know what Lake Erie looked like pre-european colonization? Lake Erie Protection and Restoration Plan (2006) with goals for water quality, pollution sources, habitat, biological indicators, boating, fishing, beaches, and tourism.

44 Ohio Lake Erie Commission

45 Restoration Principles Identify key processes that stress the system. Determine realistic goals and measures of success. Use methods that have produced success elsewhere. Monitor effectiveness.

46 Strategies Pollution control regulations (industry, urban wastewater) Alternative farming practices. Wetland protection and restoration. Fishing restrictions. Tighter control over the spread of exotics. Removal of dams.

47 Restoration Principles Identify key processes that stress the system. Determine realistic goals and measures of success. Use methods that have produced success elsewhere. Monitor effectiveness.

48 Many other methods of monitoring. Monitoring by academia, agencies, private organizations. Using indices of Biological Integrity (IBI biological), Trophic (TSI chemical/ physical/biological), time-series data, etc. Comparisons with reference systems. Publication of reports (e.g., 2004 State of the Lake Report).

49 Examples of Restoration Projects (see book Ch. 15) Harpy eagle conservation program Achieving success in mine reclamation Genetic considerations in reintroductions Restoration the Nation s wetlands Temperate riverine ecosystem restoration Tropical montane forest restoration others