Chapter 1. Introduction

1.1 Purpose

The methods, cost and benefits of traditional biodiversity indicators (for example, species counts or total hectares in protected areas) are relatively familiar to environmental decision makers. In contrast, the complexity associated with the various integral components of remote sensing (radiative transfer, satellite technology, image processing, and field ecology among others) can be intimidating to nonspecialists and may preclude the adoption of truly useful applications. In other instances, many of those who have crossed the technological divide and seen map products and statistics resulting from remote sensing analysis may be overconfident about its potential to produce accurate environmental classifications and detect characteristics of ecosystem change. In reality, while remote sensing may represent the best way to measure characteristics of change over large areas, the accuracy of a given remotely sensed product may not be high enough for certain applications and for particular users. There are several things environmental managers need to know for a practical understanding. For instance:

  • What exactly does the information from a particular satellite sensor represent?
  • How can this information be translated into a useful indicator?
  • What are the common indicators associated with each major biome?
  • What range of accuracy might one expect from a particular remotely sensed indicator, and what conditions affect this accuracy?

We address these and other questions while presenting the overall role that remote sensing can play for developing and monitoring biodiversity indicators relevant to various strategic components of the Convention on Biological Diversity (CBD). We touch on the relationships between measures made at the global level and at scales typical in national and local monitoring. We present examples of remotely sensed indicators for monitoring at the national and subnational levels. And lastly, we highlight practical tools, datasets and other resources readily accessible to remote sensing users. The indicators covered in this book are based on the list identified for immediate testing and for further development by the CBD COP8 (Decision VIII/15). We concentrate on indicators that are relevant to both international and national decision makers and for which remote sensing is a highly relevant tool. We find that remote sensing data can make a strong contribution to six of the areas of interest identified by the CBD: (1) trends in extent of selected biomes, ecosystems and habitats; (2) coverage of protected areas; (3) threats to biodiversity; (4) connectivity or fragmentation of ecosystems: (5) trends in populations of selected species; and (6) potential human development indicators. Throughout the text, we present case studies that provide a rationale and resources for commonly used indicators within the context of real projects.

1.2 Audience

Because our intent is to bridge the gaps between technical specialists, on the one hand, and biodiversity managers, environmental managers, and policy makers, on the other, both should be considered the intended audience for this publication. However, the technical level and content is directed mainly at the latter group. For those with little background in the subject of remote sensing, we include a quick overview of the basics before addressing the various indicators remote sensing could help produce. The information presented here is relevant for those involved in environmental monitoring including site-based monitoring and for those involved in governmental and intergovernmental processes. The 2010 Biodiversity Target is simultaneously a global and a national commitment that encourages countries to set national targets relevant to the 2010 assessment framework (if they have not done so already). The incorporation of 2010 Biodiversity Target and selected indicators into the Millennium Development Goals demonstrates the relevance of biodiversity and environmental monitoring for sustainable development.

1.3 Intended use

This sourcebook is intended to assist environmental managers and others who work with indicators in pursuing appropriate methods for indicator testing and production, and to offer some guidance to those responsible for the interpretation of indicators and implementation of decisions based on them. Upon reading this document, technical advisers, environmental policy makers, and remote sensing lab directors and project managers should be able to identify specific, relevant uses of remote sensing data for biodiversity monitoring and indicator development related to the CBD. It is also hoped that the sourcebook will assist in the planning and implementation of biodiversity-relevant indicators within other multilateral environmental agreements, including the Ramsar Convention on Wetlands and the United Nations Convention to Combat Desertification.

The appendices provide a greater level of detail for the environmental manager or analyst, indicating potential techniques for producing individual indicators using remote sensing, discussing technical issues, and listing available resources. However, this book is not intended as a substitute for one of the many excellent remote sensing and analysis manuals already available. Some recommended sources for further study are included in the appendices.

1.4 Organization

Chapter 2 gives the reader a general idea of the correspondence between biodiversity indicators and strengths of remote sensing technology. This chapter also outlines some of the inherent limitations of remote sensing that should be kept in mind when constructing indicators. It addresses the relevance of remote sensing measures to various CBD concepts, such as 2010 focal areas and Programmes of Work. We report on practical experience with remote sensing within the Biodiversity Indicators for National Use project which focused on the creation of practical national level indicators.

Chapter 3 offers a brief introduction to remote sensing methods and terminology. It strives to answer common questions about what remote sensing is and how it is used, and discusses general issues for the use of remote sensing within a biodiversity-monitoring framework.

Chapters 4 through 11 describe indicators identified and adopted for monitoring of progress toward the 2010 target. This section is the heart of the document, where the authors discuss a practical role for remote sensing in the development of indicators within the framework of the CBD’s focal areas. For each focal area, we describe specific remote sensing weaknesses and strengths, identify suitable data sets and outline approaches for common indicators. These chapters also contain a number of case studies illustrating methods and data products in more detail. Not all the case studies involve national-scale results, but each illustrates indicator scenarios that may be of interest when planning national assessments and monitoring systems.

The appendices contain a glossary, listing of abbreviations and acronyms, links to and descriptions of large repositories of data, training resources and remote sensing tools on the web and elsewhere. Members of the NASA-NGO Working Group and UNEP-WCMC have pooled their collective knowledge and experience to list resources that might be useful for those engaged in biodiversity monitoring.