Healing Gardens

Wetlands can be difficult to define and usually merge into other communities such as meadows and ponds. They can have standing water year round or only partially. Wetlands occur when the water table – where the ground water is the highest- is very close to the surface or above ground.  If the soil is completely saturated with water standing water will collect when it rains, if not it will saturate the soil down to where there is an impervious surface (bedrock). If there is a long period without rain than the water table will drop and the wetland will dry(1).

Wetlands are highly productive habitats and play a key role in lowland communities. They play an important role in cycling nutrients, storing excess water, alleviating flood problems, and acting as a natural reservoir in times of drought. They also are important habitats for birds that use wetlands as nurseries and stopping points during migrations (2).

Sadly, wetlands have almost countless and persistent threats. Every year 117,00 acres are lost. Key factors in the destruction of wetlands are urban sprawl, logging, mining, stream channelization, and the presence of highways and roads. The leading cause of wetland destruction is agriculture, which accounts for 79% of the annual destruction of wetlands in the continental US (3).

The wetland at the Ethnobotanical Garden is most representative of a shrub and swamp community. Willow thickets and woody plants such as red-oiser dogwood, willows, and Douglas spirea define this semi-terrestrial wetland. The plants in this community can withstand variable water flow and are found in floodplains, gravel bars, and in stream channels (1).

Sources:

1.      http://faculty.northseattle.edu/ecauldwell/bio125/wetlands_types.htm

2.      Natual History of Puget Sound Country pg 276

3.      http://faculty.northseattle.edu/ecauldwell/bio125/wetlands_threats.htm