(published 1998)
Habitat Atlas for Wildlife at Risk
Riparian & Wetland Ecosystems

Wetlands are areas where the land is wet or flooded at some time of the year, including marshes, bogs and areas of shallow open water. Riparian areas occur along the banks of lakes, rivers, and streams. Riparian areas are often linear, creating a rich habitat along miles of creeks and rivers that support a diversity of wildlife. Riparian ecosystems act as filters for overland flows carrying sediments and pollutants, while wetlands are the storage basin for floodwaters and nutrients. Riparian forests consist of black cottonwood, water birch, mountain alder, and trembling aspen trees. Their root systems reinforce and protect the banks and shorelines. Vegetation such as willow, red-osier dogwood and wild rose form tangled thickets that are ideal habitat for nesting birds.

Riparian and wetland ecosystems once covered a significant portion of the valley bottomlands in the South Okanagan, but development and flood control measures have reduced that habitat to less than 4 percent of the land area. The most significant water project was the channelization of the Okanagan River between Okanagan and Osoyoos lakes to control flooding. It is estimated that we have lost 85 percent of valley bottom riparian habitat. The remaining water-dependent communities are highly fragmented and in poor health.

In semi-arid areas like the South Okanagan and Lower Similkameen, riparian areas are important for maintaining plant and animal diversity for the whole region. Studies have shown that 80 percent of wildlife are either directly dependent on riparian ecosystems or use them more frequently than other habitats. Extensive, healthy riparian systems are critical for wildlife, and habitat restoration and protection are high priorities for wildlife management.

Threats:

• Since wetland and riparian areas cover only 4 percent of the region yet are critical for so many species, the loss of a small areas can have a dramatic effect on local wildlife populations.
• Small ponds and marshes may be permanently drained and filled for agriculture or development.
• Small lakes are sometimes poisoned and/or restocked with predatory game fish that eat amphibians and native fish species.
• Natural travel corridors running between ponds and surrounding grassland or forest habitats are often blocked by roads and surrounding development.
• Water consumption for human and agricultural uses can diminish stream flows, dry up summer breeding sites, and change mineral concentrations in ponds and lakes.
• Livestock can trample stream-side vegetation and reduce the quality of riparian habitat for wildlife.
• Sediments and chemicals from storm water discharge, agricultural fertilizers and pesticides, and sewage effluent can erode and impact on riparian and wetland ecosystems.

Wildlife at Risk for which Riparian and Wetland habitat is critical: