The biosphere is currently experiencing its sixth major species extinction crisis. For the first time, this crisis is being induced by the actions of a single species, and its consequences are both severe and unpredictable.
Over the past four billion years, the evolutionary process has created an enormous diversity of genes, species, populations, landscapes, and biomes. Current biodiversity is estimated at 10 to 100 million species, of which only 1.4 million have been formally catalogued. This number includes one million animal species (dominated by insects), 248,000 higher plants, 69,000 fungi, 31,000 protozoa, 27,000 algae, 5,000 bacteria, and 1,000 viruses.
Biodiversity maintenance is a critically important ecosystem service. biodiversity supplies a key part of cultural identity and provides the evolutionary and spiritual context for the human story. Biodiversity is the source of valuable crops, medicines, fibers, and materials. As the diversity of ecosystems increases, biological productivity and ecosystem-level stability (although not population-level stability) tend to increase. Below a critical biodiversity threshold, ecosystems are unable to sustain themselves over long time periods.
It is estimated that the current species extinction rate is one to ten thousand times greater than average levels over the last few hundred million years. This biodiversity decline has many causes: habitat loss, degradation, and fragmentation; overharvesting; invasive species introduced from distant ecosystems; toxic contamination; and others.
The Precautionary Principle dictates that each species be regarded as critically important to the fabric of life, and given full protection under the law. The Endangered Species Act passed into law in the U.S. in the 1970s, despite its flaws in implementation, embodies this position by protecting essential habitat for species facing catastrophic population declines. Instruments of last resort in preserving endangered species, like Habitat Conservation Plans, should be designed to build community and provide incentives for ecologically compatible uses of the landscape.
In the longer term, biodiversity can only be systematically protected through ecological land-use that provides for a matrix of connected wildlands. This wildlands backbone provides insurance against habitat loss and fragmentation by maintaining a sufficient quantity, quality, and connectivity of protected habitat for all terrestrial, freshwater, and marine species. Significant incentives for establishing an effective system of connected wildlands can be provided by using true cost pricing for the ecosystem services they provide.
Better forestry practices can maintain a full level of biodiversity, and agriculture a high percentage, by applying appropriate landscape ecology principles to maintain habitat connectivity and diversity. In addition, agricultural systems can be designed to mimic the functional diversity of natural ecosystems, like many traditional farming practices throughout the world. Urbanized areas can integrate critical habitats into an ecological infrastructure designed to optimize ecosystem services.
Maintain biodiversity by establishing a system of connected wildlands, practicing ecologically-minded forestry and agriculture, employing better materials cycles, and using fair trade to avoid the spread of invasive species.
Examples of this pattern in action:
The Nature Conservancy
The Nature Conservancy's mission is to preserve the plants, animals and natural communities that represent the diversity of life on Earth by protecting the lands and waters they need to survive.
Organizations whose work incorporate this pattern:
Schulze, E.D. and Mooney H.A., eds.. Biodiversity and Ecosystem Function. Springer-Verlag. Berlin, Germany. 1993.
Wilson, E.O.. The Diversity of Life. W.W. Norton and Company. New York, NY. 1993.