Restoring Disturbed Landscapes: Putting Principles into Practice
216
Restoring Disturbed Landscapes: Putting Principles into Practice
216eBook
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Overview
Written by restoration experts with a wealth of experience teaching restoration principles and techniques to practitioners and would-be practitioners from a variety of backgrounds, the book offers:
- an outline of a science-based, ecologically sound approach to restoration
- discussion of the conceptual framework and rigorous principles that underlie the approach
- case studies of two types of restoration projects (restoring mined landscapes and restoring damaged rangelands) that illustrate how the approach, framework, and four key principles for restoring landscapes have been implemented
- a variety of scenarios that represent typical restoration problems and how those problems can be handled
- indicators for monitoring and how landscape function can be tracked and analyzed as part of a comprehensive monitoring program.
Product Details
| ISBN-13: | 9781610910071 |
|---|---|
| Publisher: | Island Press |
| Publication date: | 03/15/2011 |
| Series: | The Science and Practice of Ecological Restoration Series |
| Sold by: | Barnes & Noble |
| Format: | eBook |
| Pages: | 216 |
| File size: | 14 MB |
| Note: | This product may take a few minutes to download. |
About the Author
David Tongway is a soil scientist and landscape ecologist who worked for Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO) for 38 years. He is an Honorary Fellow at CSIRO’s Gungahlin Laboratory in the Australian Capital Territory.
John Ludwig is a plant and landscape ecologist who worked in the Biology Department, New Mexico State University, in Las Cruces,1969–1985 and for CSIRO, 1985–2007. He is currently an Honorary Fellow at CSIRO’s laboratory in Atherton, Queensland.
Read an Excerpt
Restoring Disturbed Landscapes
Putting Principles into Practice
By David J. Tongway, John A. Ludwig
ISLAND PRESS
Copyright © 2011 David J. Tongway and John A. LudwigAll rights reserved.
ISBN: 978-1-61091-007-1
CHAPTER 1
Our Approach to Restoring Disturbed Landscapes: A Five-Step Adaptive Procedure
In this chapter we describe our approach, which we feel is central to Restoring Disturbed Landscapes. We think of our approach as an orderly five-step adaptive procedure for restoring landscapes, or for short, adaptive landscape restoration. It comprises a sequence of steps (figure 1.1) where stakeholders in the disturbed landscape work with the restoration practitioner (hereafter abbreviated as RP) to (1) articulate the goals of restoration, (2) define and carefully analyze the problem, (3) identify appropriate solutions, (4) select treatments to apply, and (5) monitor restoration indicators and assess progress as trends in these data. If trends are negative, RPs should then adaptively revise treatments to improve trends. In practice, we view this procedure like planning a journey using a road map. The start and end points are known, but there are options to exercise in the actual route taken to reach the destination—the successful restoration of a landscape.
Before describing each of the five steps in our adaptive landscape restoration procedure we make a few observations and note some of its key features. We emphasize that our adaptive procedure is not a prescription or recipe for RPs to follow like a global positioning system (GPS)–guided route from start to finish. As with planning a journey, choices made at each road junction along the way require critical analysis and careful consideration. Sometimes the choice of route is crucial; sometimes options are roughly equivalent. The shortest route is not necessarily the most appropriate. For example, on revegetated mine sites, RPs often sow (in suitable climates) the colorful, exotic red natal grass because it quickly provides an attractive cover. However, red natal is a tufted grass (big top, small base), and from our monitoring experiences, we know it usually fails to adequately function to prevent soil erosion on sloping sites (even if soil materials are only moderately erodible). We have found that a better option for protecting sloping rehabilitated surfaces against erosion is to revegetate mine sites with native, spreading perennial plants.
In designing ways to restore the functional capacity of damaged landscapes, we first need to be clear about what we are aiming to achieve. The next step is to critically analyze the problem: Which landscape goods and services have been lost and which have been retained? What landscape processes have become ineffective? What caused losses in capacity? By understanding the problem, RPs can design solutions by selecting and applying appropriate landscape restoration technologies. The restoration procedure must include monitoring, that is, RPs need to collect data to evaluate whether gains in capacity have been achieved. If gains have not been achieved, then they need to go back and reexamine whether the goals are still appropriate (e.g., are they too ambitious?).
In most cases, goals will remain appropriate, but we sometimes find that we underestimated the importance of some processes so that some technologies need to be adjusted. This revision to improve restoration is called an adaptive learning loop (figure 1.1), which is an essential component of an adaptive landscape restoration procedure. After adjusting technologies, the RP must continue monitoring and analyzing data to see if restoration trends are toward desired goals. With time, these monitoring data will confirm if goals are being successfully achieved.
Our Five-step Procedure
Step 1: Setting goals
In step 1, stakeholders, or those with an interest in restoring a specified landscape, set goals that clearly define what they aim to achieve. When setting restoration goals, stakeholders require a clear understanding of underlying constraints, such as whether goals are driven by regulations, laws, or treaties, or by agreements based on the aspirations of particular stakeholder groups. Often the groups involved in defining and setting restoration goals have different views about the initial state or condition of the landscape being restored, as well as having different desires for the shape, appearance, and final use of the restored landscape. To have clearly defined, agreed upon goals, conflicting views and competing tensions need to be resolved.
Goals need to be stated in measurable terms so that RPs can collect the data that measures both progress toward the final goal and validates its achievement (i.e., whether rehabilitation trends are heading in the right direction and at an appropriate rate). If progress is lacking, monitoring data must provide the information needed for RPs to adjust technologies.
Step 2: Defining the problem
In step 2, stakeholders and RPs work together to carefully analyze the specific problem. This is a logical progression from having a clear understanding of constraints and goals. Step 2 involves a critical analysis of the landscape as a biophysical-socioeconomic system and the causes of the problem, not just a list of the symptoms. This analysis includes knowing the seriousness of the problem, how quickly it needs to be solved, and what information is available, or needs to be collected, to better understand the problem.
As well as identifying the underlying causes of the disturbance, we view step 2 as an analysis of damaged landscape processes, what we call dysfunctional landscapes (Tongway and Ludwig 1996, 2007). Background information also needs to be evaluated, ideally from reference sites in landscapes that reflect the level of functionality aimed for in restoration goals. Reference sites provide stakeholders and RPs with a clearer perception of the magnitude of the problem by highlighting the gap in functionality between the damaged landscape and the reference landscape.
Step 3: Designing solutions
In the third step, stakeholders and RPs examine possible solutions to the problem. Their aim is to identify the biophysical, social, and economic processes that need to be improved to achieve the desired goals. We view step 3 as landscape restoration design, rather than technology selection, because to deal most effectively with the problem this step focuses on understanding and articulating the processes and functions that need restoring.
Step 4: Applying technologies
In step 4, stakeholders and RPs select appropriate solutions and technologies to apply. This is crucial, because if an inappropriate technology is chosen, or if an action is delayed, subsequent remedial (adaptive) actions may be very costly. For example, applying a treatment that inadvertently exposes a dispersive soil B horizon can lead to gully erosion that is very difficult and costly to repair.
Step 4 involves an if–then decision-making process where possible technologies are examined relative to problems and goals. Decision-making criteria include factors such as cost and technical difficulty. If, after being selected and applied, the RP finds that the technology does not lead to the desired goals, it is modified or replaced (revised by adaptive learning; figure 1.1). Examples of adaptive learning being applied to achieve desired restoration goals are presented in chapters of parts 2 and 3.
Step 5: Monitoring and assessing trends
The fifth step is about RPs monitoring the outcomes of applied technologies over time and then evaluating trends in monitoring data. It involves establishing a baseline by collecting data before, and as soon as possible after, implementing the selected rehabilitation technologies. To provide context and benchmark data, the RP needs to collect monitoring data from reference sites. These data provide the basis for evaluating the overall trend in rehabilitation progress over time and answering questions such as, are trends in the data toward values expected from measurements taken on reference sites?
We view the trend analysis phase of step 5 as an active and essential part of monitoring. This is important because if the RP detects unsatisfactory progress toward goals early on, rehabilitation technologies can be adapted to improve progress; this can greatly reduce costs of repairing future failures. The process of evaluating trends also adds to our knowledge about the landscape.
It is also important that RPs collect data over a sufficient length of time to detect genuine restoration trends. Then they can confidently ask the question, are trends OK? If not, this flags a need for RPs to reexamine goals, reanalyze the problem, and redesign solutions, which may simply lead to a modification of an already applied technology.
Further Thoughts
Over the years we have observed that less successful rehabilitation has usually glossed over one or more of the steps in our five-step adaptive landscape restoration procedure or has not put basic landscape function concepts and principles into practice. We describe these concepts and principles in chapters 2 and 3. We have observed that successful restoration can be achieved in deserts, grasslands, shrublands, savannas, woodlands, forests, and rainforests by putting these concepts and principles into practice within our five-step adaptive procedure. Sometimes this success was achieved by intuition, rather than by formally following our five-step procedure, but retrospective evaluation showed that all steps had been taken in order.
CHAPTER 2A Framework for How Landscapes Function
People see landscapes differently: Some people respond mainly to the topography, that is, the shapes of mountains, hills, and valleys; others respond mainly to the diversity of the trees, shrubs, grasses, birds, and so on. However, to understand how disturbances affect landscapes so that a restoration practitioner (RP) can design effective projects, we believe it is important to view landscapes as functioning systems (Ludwig and Tongway 2000). We feel that with a function-based approach, landscape restoration becomes a matter of making the system work properly, rather than just replacing organisms that might be missing.
Landscapes, defined as interconnected ecosystems, are complex and dynamic (Tongway and Ludwig 2009). We marvel at the biological diversity of landscapes, such as tropical rainforests, and at the power of physical forces on landscapes, such as by glaciers. Landscapes that we also find fascinating are those that slowly tick along and then suddenly spurt into action because of an event such as a rainstorm. Arid and semiarid shrublands, grasslands, and savannas are examples of such landscapes; they have alternating slow and then fast dynamics, and they are sometimes referred to by scientists as pulse-and-decline and stop-go ecosystems, because they stop or slow down when water is limiting and become active when it is available (Westoby et al. 1989; Robin 2007).
Landscapes range in size (scale) from small to large depending on the extent of the area being considered by different groups. For example, a local community group may be interested in repairing a damaged hillslope of a few hectares, whereas a regional natural resource management group may be interested in the health of a river catchment of thousands of hectares. Given this variation in landscape scale, and the complexity and dynamics of landscapes, the question is, what can we do to help understand how disturbed landscapes function so that we can readily repair damaged processes?
In this chapter our aim is to describe what scientists call a conceptual framework, which is a device that enables us to structure or make sense of all the information we have about a landscape as a complex and dynamic process-based system (Ryan et al. 2007). In constructing a framework, we take care to be comprehensive and to not inadvertently omit important processes. Such frameworks, once fully developed, enable observers to read the landscape and understand why landscapes have become dysfunctional and fail, to some extent, to provide the goods and services desired by humans. We emphasize that conceptual frameworks help us design and apply effective restoration technologies by identifying defective or missing processes.
Although conceptual frameworks can take different forms, here we use box-and-arrow diagrams where we label boxes to represent the functioning biological (biotic) and physical (abiotic) components of the landscape system. We position boxes in our diagrams to represent the order, or sequence, of interactions between components of the system. Arrows are used to illustrate resource flows between and in and out of the components of the system. For example, rainwater enters a landscape as an external input and then flows as runoff within the landscape. These flows of water may then be captured by internal components, such as patches of vegetation, or water may run out of the defined landscape area into a different area, such as a creek or river located down the catchment. Flows of resources out of a landscape system represent external outputs.
Because water is essential to all life, the main focus in our conceptual framework is on the role of water. We provide examples of processes where water and materials such as soil particles and organic matter carried in Runoff water enter, move around, are stored, utilized, and leave the landscape system. At times we also note how this framework applies to flows of materials driven by other forces, for example, wind-blown dust particles.
This focus of our conceptual framework on those biological and physical processes, such as water-driven soil erosion and growth of vegetation, is, in part, due to our area of expertise, but we feel strongly that this focus on biophysical processes is very important when restoring landscapes. We hasten to note, however, the important role that socioeconomic processes play in restoring landscapes, for example, in setting goals. (See step 1, figure 1.1 in chapter 1.) Socioeconomic criteria are also important in evaluating whether landscape restoration goals have been successfully achieved. Such evaluations can have huge economic consequences. For example, bonds worth millions of dollars may not be returned to mining companies after mine closure until they can demonstrate to regulators that they have successfully rehabilitated damaged landscapes.
Our Conceptual Framework
In this section we build a conceptual framework composed of landscape components (boxes) and processes (arrows). Our framework defines how materials flow into, around, and out of components of the landscape system. Our aim is to describe how landscapes function as complex and dynamic systems involving a sequence of important processes between components, but without introducing too much detail. We build our framework piece by piece, starting with external inputs and ending with external outputs, and put it all together in one diagram at the end. We illustrate how to put the framework to work by examples in chapters of parts 2 and 3. In the chapters of part 4, we describe how monitoring allows acquisition of data about changes and trends in landscape components and processes; these data are needed to evaluate whether trends are toward those specified by restoration goals.
(Continues...)
Excerpted from Restoring Disturbed Landscapes by David J. Tongway, John A. Ludwig. Copyright © 2011 David J. Tongway and John A. Ludwig. Excerpted by permission of ISLAND PRESS.
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Table of Contents
Foreword\James AronsonPreface
Acknowledgments
PART I. A Function-Based Approach to Restoring Disturbed Landscapes
Chapter 1. Our Approach to Restoring Disturbed Landscapes: Five-Step Adaptive Procedure
Chapter 2. A Framework for How Landscapes Function
Chapter 3. Principles for Restoring Landscape Functionality
PART II. Case Studies on Restoring Landscapes: Mine Sites and Rangelands
Chapter 4. Restoring Mined Landscapes
Chapter 5. Restoring Damaged Rangelands
PART III. Scenarios for Restoring Landscapes: Mine Sites, Rangelands, Farmlands, and Roadsides
Chapter 6. Restoration of Mine-Site Waste-Rock Dumps
Chapter 7. Restoration of Mine-Site Tailings Storage facilities
Chapter 8. Restoring Landscapes after Open-Cut Coal Mining
Chapter 9. Restoring Rangelands with an Overabundance of Shrubs
Chapter 10. Renewing Pastureland Functions Using Tree Belts
Chapter 11. Restoration of Former Farmlands near Urban Developments
Chapter 12. Restoring Verges after Road Construction
PART IV. Monitoring Indicators
Chapter 13. Landscape Function Analysis: An Overview and Landscape Organization Indicators
Chapter 14. Landscape Function Analysis: Soil-Surface Indicators
Chapter 15. Ephemeral Drainage-Line Assessments: Indicators of Stability
Chapter 16. Vegetation Assessments: Structure and Habitat Complexity Indicators
Chapter 17. Reflections on Restoring Landscapes: A Function-Based Adaptive Approach
References
Glossary
Further reading
About the Authors
Index