Scientists are finding extremely disturbing trends in many measures of the health of our environment, and they are continuing to document the ominous decline of many species and ecosystems. Some of the declines are enigmatic, some of them are beginning to be understood, and in some cases the causes are clear and are a result of human overexploitation, land conversion, or environmental contamination. Although it may be depressing to see so many signs of loss, it behooves us to document and analyze these changes so that we can start to understand the real costs of human domination of the planet.

Unfortunately scientists can do only a small fraction of the monitoring that these changes call for. Even if environmental science were well funded, we would still be faced with the problem that the data points (individual organisms or populations of animals, plants, or microbes) are often widely scattered over large areas, and data collection by remote sensing is now possible only for a limited set of the organisms of interest. The seasonality of distribution patterns is also of interest and compounds the problem of comprehensive data collection.

The public can be a tremendous resource for scientists interested in monitoring nature. There are plenty of skilled and observant people with knowledge of particular taxa or geographic areas, who are often passionate about these interests and are delighted to discover that their work may be useful. Many of them have independently developed knowledge bases and are collecting photographs of species, life cycles, behaviors, and the place of animals and plants in the wild. Others have become organized to carry out regular counts of birds or butterflies so that interesting trends may be detectable. Still more people have joined or started organizations for which one of the goals is to document and monitor certain taxa or geographic areas.

Although a global study of the engagement of the public in biodiversity issues would be of great interest, it has yet to be done, so some of my comments will be restricted to local trends in public engagement.

Orange County is the smallest county in Southern California, with a total land area of 789 square miles, but its population of over 3 million people makes it the second most populous county in the state, with the highest population density (3,822 persons/square mile in 2004) outside