We depend on plants for everything; now they need our help. By mid-century, the United States may witness the extinction of 25% of its native plant species, with equal or greater losses expected for plant species worldwide. Conservation of wildlife tends to receive more attention than plants. But because all life depends on plants, conserving plants is critical to the survival of all of Earth's biodiversity. If plants go extinct, many other species will follow. Plants are essential components of all ecosystems. Other species depend on them for food and shelter. Plants improve air and water quality, help regulate climate, and control water flow. Yet countless plant species are threatened by habitat loss and fragmentation, climate change, invasive species, pollution, and more.
Plants do far more for ecosystem -- and for us than we realize. Our most basic necessities, including food, oxygen, fibers, medicines, and most forms of energy, come from plants and plant processes. As integral members of natural communities, plants regulate processes that improve the quality of air and water, help control climate, recycle nutrients, and limit flooding and soil erosion.
Compared to some animal groups, such as birds and mammals, the number of plant species is poorly known. That's because there are so many plant species -- more than 350,000 species known to scientists -- and more yet to be discovered.
Human-related activities account for more than 80% of the threats to plant diversity. Among the greatest of these is habitat loss and degradation. Plant habitat is shrinking, being destroyed by residential and commercial development, tourism, logging, mining, and agriculture. Climate change is becoming an increasingly serious threat to plants as well. Invasive species also imperil plant communities. Invasive species are those that, when introduced to an area where they don't naturally occur, spread out-of-control and overrun entire areas. Pollution and illegal collecting also are among factors endangering plant species.
The best strategy to conserve plants is to protect them in their habitats. This makes it essential to protect natural environments, and manage protected areas to benefit species diversity. Many conservation organizations also work to restore degraded habitats to health and improve native species diversity.
Botanic gardens -- beyond protecting species in live collections and seed banks -- promote plant conservation in many ways. Botanic Gardens Conservation International, with more than 100 members among botanic gardens and conservation organizations in the United States alone, works to implement the Global Strategy for Plant Conservation (GSPC) to halt the loss of plant diversity around the world. GSPC is a program of the United Nation's Convention on Biological Diversity. Botanic gardens also conduct programs in natural environments. Garden scientists monitor and study wild plant populations to help policy makers and land managers conserve them more effectively.
You can get involved in plant conservation activities as a citizen scientist. For example, the Chicago Botanic Garden's Plants of Concern program engages a network of volunteers, trained by scientists, to monitor the health of 185 endangered, threatened, or rare plant species in the Chicago area. Data are analyzed to identify relationships between plant population health and environmental changes, and to help inform land management decisions.
Contributed by Kay Havens, Medard and Elizabeth Welch Director, Division of Plant Science and Conservation and Senior Scientist, Chicago Botanic Garden; Andrea Kramer, Conservation Scientist, Ecological Genetics and Executive Director, Botanic Gardens Conservation International U.S.at Chicago Botanic Garden ; and Francie Muraski-Stotz, free-lance writer.