Wednesday, February 24, 2010

Wetland Function and Value

The photo shows skunk cabbage which blooms in the marsh in Spring.  It is a typical wetland plant that grows in areas that are inundated through part of the year, usually in Winter and Spring.  Wetlands are identified using combinations of hydrology, vegetation, and soils.  These criteria are matched with regulatory definitions to delineate and map precise boundaries for wetlands.  Two primary standards are used presently; the U.S. Fish and Wildlife Service definition and the U.S Army Corps of Engineers definition.  States and local governments may also have specific definitions amended to the federal standards.  
Evaluating and understanding the functions and values of wetlands is important because no net loss of function or function and value are standards applied in federal, state, and local regulations.  Function and value are also important in planning, acquisition, and management of wetlands.  Evaluation of wetlands is usually made through analysis of four factors.  The 1st includes natural processes occurring within wetlands.  Examples include denitrification, biomass production, and flow retardation.  The 2nd factor includes offsite natural resources that are critical to wetland processes.  Examples include watershed hydrology, habitat connectivity, and presence or absence of buffers.  The 3rd factor is cultural context of wetlands in the watershed.  These may include roads, dams, houses, farms, and factories.  The 4th factor is the society attitudes towards the roles and outputs of wetlands.

Beaver Creek Marsh © Roy Lowe
Functions of wetlands match well with factors 1 and 2, while values match well with functions 3 and 4.  These factors can be evaluated by quantitative studies, surveys of public opinion, and consulting political will and legal statutes.  The functions and values may change over time and can be enhanced or degraded by changes occurring in the watershed and in social factors.  The dynamic nature of these functions and values makes analysis of wetlands for education and regulation difficult at best and subject to differences in opinion and political power.  A wetland in one community may be valued highly, while in another community, the same wetland may be viewed as having little or no value and as an obstacle to economic development. 
What are some of the functions and values of wetlands?  They can provide: flood storage and conveyance; erosion control; crops and timber; groundwater recharge and discharge; atmospheric gas exchange; micro-climate modification; habitat for fisheries and for other mammals, reptiles, amphibians, and endangered or threatened species; scenic beauty; recreation opportunities; historical, archaeological, and heritage value; and education and research opportunities.  Wetlands can reduce wave damage to shores and sediment loading in open bodies of water, and can prevent and treat pollution from upland areas.
Clearly some or all of these functions and values may have importance for different communities.  Since social structure varies among urban and rural settings and political persuasions, we can easily see the difficulty for objectively assessing the functions and values of wetlands.  Wetlands are rich in habitats, species, and connectivity and can be an important meeting ground for reconciliation of differences in opinion and philosophy and for understanding how society changes in an historical context.  The present use of Beaver Creek Marsh as a classroom and recreation area provides many opportunities to explore and research the genesis of natural systems, culture, and human viewpoints.  
Beaver Creek Marsh is a prime example for the effects of history on the changing interactions of society and wetlands.  Pre-history uses by humans were defined by harvesting of natural resources.  The development of farms and logging by early settlers attempted to enhance economic resources beyond simple hunter-gatherer activity.  Initially farmers sought to dredge, dike, and drain wetlands to increase pasture land.  As costs for farming increased, residents turned to day jobs in urban areas for income and later generations eventually became more willing to recognize the natural values of wetlands by granting conservation easements or sales of wetlands for economic gain.  As urban areas increased, more people turned to recreational opportunities available in the marsh.  Now the Beaver Creek State Natural Area is being developed by Oregon State Parks.  This Natural Area will be the Featured State Park in 2010 and many more people will come for recreation and to appreciate the natural beauty and values of Beaver Creek Marsh in the future.  The marsh and adjacent uplands and forest will be an incredible jewel and legacy in the future, conserving the natural functions of a rare coastal wetland and its watershed for generations to come.    
Posted by michael

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