examples were available that such restoration could be done relatively quickly and at 

 a cost that would not bankrupt society, more action might result. Ecologists have not 

 covered themselves with glory in the area of recovery. They prefer to work mostly 

 with pristine ecosystems rather than already damaged ones. As a consequence, there 

 is a paucity of basic information that would make restoration efforts more efficient 

 and expeditious. Nevertheless, evidence shows that present information and 

 practices are adequate to do the job quite effectively. Consequently there is no 

 scientific justification for postponing major restorative efforts. 



EPA'S ROLE 



Ecological systems provide society with values that can be categorized as goods, 

 services, esoteric values, and long-range self-maintenance. Pursuant to maintaining 

 the quality of the human environment, a keen interest in restoring disturbed or 

 damaged ecosystems as well as those systems which may become disturbed through 

 human activity, should be shown. Clearly, some of these systems must be returned 

 to, and maintained in, their natural or near-natural state if our natural heritage is to 

 be protected for future generations. Still other ecosystems will be restored to some 

 relatively stable, but less than natural, state capable of providing society with goods 

 and services. 



Moreover, ecosystems restoration are best carried out with a full knowledge of the 

 structural and functional characteristics of the conditions which are sought. Also, 

 restoration should involve the most effective and efficient technology available. 

 These technologies include effective manipulation of physical and chemical qualities 

 of habitats, and effective species stocking and restoration programs. The emerging 

 field of ecosystem restoration and enhancement has become a cornerstone of 

 ecosystem management. 



Those involved in this new technology must develop a detailed knowledge of the 

 effects of each type of system perturbation. Rates of recovery and limits of tolerance 

 beyond which perturbed systems cannot recover to desired states must be known and 

 understood. All this information must be coupled with a knowledge of reversing 

 conditions of disturbed systems. 



In developing this new field, research should now be carried out in certain critical 

 areas with a focus on specific ecosystems types. The sections that follow identify 

 critical research needs. 



Factors Important to the Restoration Process 



Damage and subsequent recovery potential of stressed ecosystems depend upon 

 three basic sets of factors: (a) type of system perturbed, (b) nature of the disturbance, 

 and (c) mode of operation of the disturbing agent. 



Representative Types of Ecosystems That May be Perturbed 



Ecosystem types can be grouped conveniently into 10 categories: forests, 

 grasslands, deserts, dry tundra, lakes, shallow wetlands (marshes, swamps, bogs, 

 coastal wetlands, and wet tundra), streams and rivers, estuaries, continental shelves, 

 artificial ecosystems (e.g., agricultural lands and reservoirs). The compositions and 

 processes of these ecosystem types vary in relation to climate, geographic location 

 and altitude. 



An estuary in Oregon may differ in species composition and certain basic 

 functional characteristics from one in Louisiana or Massachusetts. Consideration 

 should be given to this heterogeneity when tolerance and responses to perturbations 

 are studied. Furthermore, a conscientious attempt should be madeto understand the 

 restoration needs of each system type in terms of its unique and shared qualities. 



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