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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy Appendix B— Glossary If you wish to converse with me, define your terms. Voltaire A ARTIFICIAL MARSH CREATION— Simulation of natural wetland features and functions by topographic and hydraulic modification of nonwetland landscapes. Typical objectives of artificial marsh creation include ecosystem replacement or storm water management. B BANK STABILIZATION— Methods of supporting the structural integrity of earthen stream channel banks with structural supports to prevent bank slumping and undercutting of riparian tress, as well as overall erosion. Recommended bank stabilizing techniques include the use of willow stakes, overlapping riprap, or brush bundles. BIOGEOGRAPHIC REGION— Any region delineated by its biological and geographic characteristics. BIOLOGICAL MONITORING— Surveillance to ensure that previously established quality control conditions are being met. Biological monitoring surveys can span the trophic spectrum from algae and other aquatic plants, to macroinvertebrates, to fish species. C CHANNELIZATION— Straightening of the meanders in a river system to create more navigable waterways, or when accompanied by channel deepening to provide flood control. COMPENSATION— Provision for creation or restoration of "equivalent" wetland acres comparable to wetland acres and functions that have been destroyed.
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy CREATION— Bringing into being a new ecosystem that previously did not exist on the site. D DIATOMS— Microscopic plants are abundant in plankton. They sometimes produce a water "bloom" and give a yellowish or brownish tint to the water. Diatoms are notable for their shells of silica and the siliceous character imparted to bottom deposits by their remains. E ECOLOGICAL INTEGRITY— Maintenance of the structure and functional attributes characteristic of a particular locale, including normal variability. ECOREGIONS— Ecological regions that have broad similarities with respect to soil, relief, and dominant vegetation. ECOSYSTEM— A biological community together with the physical and chemical environment with which it interacts. ECOSYSTEM CREATION— Construction of an ecosystem with new species, soil, and vegetation on a site that had a different type of system before destruction or damage occurred. (See creation.) ECOSYSTEM FUNCTION1— Any performance attribute or rate function at some level of biological organization (e.g., energy flow, detritus processing, nutrient spiraling). EMERGENT PLANTS— Aquatic plants that are rooted in the sediment, but whose leaves are at or above the water surface. These wetland plants provide habitat for wildlife and waterfowl in addition to removing urban pollutants. ENHANCEMENT— In the context of restoration ecology, any improvement of a structural or functional attribute. Odum et al. (1979) have defined whatever contributes to enhancement as a subsidy. EPILIMNION— In a thermally stratified lake, the turbulent layer of water that extends from the surface to the metalimnion. EUTROPHICATION— Enrichment of lakes with nutrients. Increase in nutrients required for the growth of organisms may come about by natural processes, or rapid enrichment may take place due to some cause such as introduction of sewage effluent. EUTROPHIC LAKES— "Rich" lakes; those well provided with the basic nutrients required for plant and animal production. In some lakes this enrichment becomes harmful, and light penetration and oxygen production are insufficient to maintain productivity. Oxygen is then consumed at a rate equal to that at which it is produced. F FLOODPLAIN— Defined by hydrologists as the area flooded at a recurrence interval of once in 100 years (Bhowmik and Stall, 1979). Ecologists define floodplains as areas that are periodically inundated (usually annually) by the lateral overflow of rivers or lakes, or by direct precipitation or ground water; the resulting physico-chemical
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy environment causes the biota to respond by morphological, anatomical, physiological, phenological, and/or ethological adaptations, and to produce characteristic community structures (Junk et al., 1989). FLOOD PULSE CONCEPT— The idea that the pulsing of river discharge, the flood pulse, is the major force controlling biota in river-floodplain systems (Junk et al., 1989). Lateral exchange between the floodplain and river channel, and nutrient cycling within the floodplain, are postulated to have a more direct impact on biota than does nutrient spiraling from upstream to downstream in the river channel; the bulk of the animal biomass in such a system is believed to be derived from production in the floodplain, not from downstream transport of organic matter produced elsewhere in the basin. FUNCTIONAL EQUIVALENCY 1— Ability of a restored or created ecosystem to perform ecosystem services, such as floodwater storage or pollutant detoxification, that are indistinguishable in effects from corresponding services performed by natural ecosystems. FUNCTIONAL IMPROVEMENT 1— Improving a functional attribute by restoring an ecosystem, preferably without impairing other attributes. FUNCTIONAL VALUES 1 — With regard to ecosystems, any attributes perceived to have societal value (e.g., waste transformation, carbon dioxide removal). G GREENWAY — A protected linear open-space area that is either landscaped or left in its natural condition. It may follow a natural feature of the landscape, such as a river or stream, or it may occur along an unused railway line or some other right of way. H HYPOLIMNION — In a thermally stratified lake, the layer of water below the thermocline and extending to the bottom of the lake; water temperature in the hypolimnion is virtually uniform. HYPORHEIC — Pertaining to the hyporheos. HYPORHEOS — The saturated zone beneath a river or stream consisting of substrate, such as sand, gravel, and rock, with water-filled interstitial pore. The zone often extends beyond the width of the stream channel and is typically used by certain aquatic organisms during their normal life cycle and as a refuge. L LANDSCAPE ECOLOGY — An emerging specialty that deals with the patterns and processes of biological systems in spatially and temporally heterogeneous environments. LANDSCAPE PERSPECTIVE — A way to view interactive parts of a watershed not necessarily all within one watershed.
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy LENTIC WATERS — Still waters such as lakes or ponds; any body of standing water. LOTIC WATERS — Any body of moving or flowing water such as a river or other stream. M MESOTROPHIC LAKE — A lake that is intermediate in fertility, neither notably high nor notably low in its total productivity. Intermediate between oligotrophic and eutrophic. METALIMNION — In a thermally stratified lake, a layer of water between the epilimnion and hypolimnion that is characterized by a sharp change in temperature or density with depth. MITIGATION — Actions taken to avoid, reduce, or compensate for the effects of environmental damage. Among the broad spectrum of possible actions are those that restore, enhance, create, or replace damaged ecosystems. N NATIVE FISH REINTRODUCTION — The final phase of a stream restoration effort, in which fish are reintroduced into a physically restored stream system to reestablish the original fish community. O OLIGOTROPHIC LAKES — Lakes poorly provided with the basic nutrients required for plant and animal production. OPPORTUNITY-COST ANALYSIS— Accepts a human-based determination of value but looks to collective action to define values achieved by restoration. This type of analysis of a restoration effort differs from traditional benefit-cost analysis. Continually questioning the value of a restoration by asking whether an action is ''worth" its cost is the most practical way to decide how much restoration is enough. P PATCH OF AN ECOSYSTEM — The term patch dynamics is used regularly in the newly developing fields of landscape ecology and conservation biology, but it has been used previously as a standard ecological term. Use of the term patch recognizes that most ecosystems are not homogeneous, but rather a group of patches or ecological islands that are recognizably different from the parts of the ecosystem that surround them but nevertheless interact with them. R RECLAMATION— A process designed to adapt a wild or natural resource to serve a utilitarian human purpose. Putting a natural resource to a new or altered use. Often used to refer to processes that destroy native ecosystems and convert them to agricultural or urban uses. REHABILITATION— Used primarily to indicate improvements of a visual nature to a natural resource; putting back into good condition or working order.
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy RESOURCE SPIRALING— Combined process of resource cycling and downslope or downstream transport (Elwood et al., 1983). A nutrient atom or organic molecule may pass through the same trophic level or chemical state (cycling) during its residence in a stream, but completion of the cycle involves some downstream displacement before the cycle is closed (spiraling). RESTORATION— Return of an ecosystem to a close approximation of its condition prior to disturbance. RIPARIAN REFORESTATION— Replanting of the banks and floodplains of a stream with native forest and shrub species to stabilize erodible soil, improve both surface and ground water quality, increase stream shading, and enhance wildlife habitat. RIPARIAN VEGETATION— Hydrophytic vegetation growing in the immediate vicinity of a lake or river close enough so that its annual evapotranspiration represents a factor in the lake or river regimen. RIPARIAN ZONE— The border of banks of a stream. Although this term is sometimes used interchangeably with floodplain, the riparian zone is generally regarded as relatively narrow compared to a floodplain. The duration of flooding is generally much shorter, and the timing less predictable, in a riparian zone than in a river floodplain. RIVER CONTINUUM CONCEPT— The idea that a continuous gradient of physical conditions exists from headwaters to mouths of rivers, and that structural and functional characteristics of biological communities are adapted to conform to the most probable position or mean state of the physical system (Vannote et al., 1980). Producer and consumer communities establish themselves in harmony with the dynamic physical conditions of a given reach, and downstream communities are fashioned to capitalize on the inefficiencies of upstream procession of organic matter. Both upstream inefficiency (leakage) and downstream adjustment seem predictable. RIVERINE WETLANDS— Wetland systems of less than 0.5 ppt ocean salts, exposed to channelized flow regimes. Riverine wetlands are categorized according to flow regimes such as tidal waters, slow-moving waters with well-developed floodplains, fast-moving waters with little floodplain, and intermittent systems. ROUGH FISH— Species, such as carp and sucker, considered undesirable by anglers. S SELF-MAINTAINING SYSTEM— An ecosystem that can perform all of its natural ecological functions without human intervention or dependence on engineered structures.
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy SERIAL DISCONTINUITY CONCEPT— The idea that dams shift the physical and biological characteristics of streams and rivers away from the pattern predicted by the river continuum concept (Ward and Stanford, 1983). A dam may make conditions more like those of the headwaters (an upstream shift) or more like those downstream, or it may have a negligible effect. Multiple dams create multiple discontinuities in the expected or natural pattern of streams and rivers. SPATIAL HETEROGENEITY— Variation in the attributes of an environment over space. SPIRALING— See resource spiraling. STREAM BUFFER— A variable-width strip of vegetated land adjacent to a stream that is preserved from development activity to protect water quality and aquatic and terrestrial habitats. STREAM ORDER— Rivers and streams are classified by order. The order of a river or stream is a dimensionless number that indicates how many tributaries it has. The smallest unbranched tributary in a watershed is designated order 1. A channel formed by the confluence of two such tributaries is designated order 2. Where 2 order tributaries join, a channel segment of order 3 is formed, and so on. In general, the higher the order number, the larger is the watershed, and the greater are the channel dimensions and discharge (Chow, 1964). STREAM RESTORATION— Various techniques used to replicate the hydrological, morphological, and ecological features that have been lost in a stream due to urbanization, farming, or other disturbance. SURVEILLANCE— Periodic and systematic surveys undertaken to determine the condition of an ecosystem. SYSTEMS PERSPECTIVE— A synthesis of all the components that collectively interact in such a way that effects on one component affect the entire system. T THERMOCLINE— In thermally stratified lakes, the layer below the epilimnion. It is the stratum in which there is a rapid rate of decrease in temperature with depth; a minimum of one degree centigrade per meter in depth. TIDAL MARSH— Salt or brackish wetland systems subject to tidal flow patterns. Marsh estuaries are subdivided into subtidal (permanently flooded) or intertidal (temporarily flooded) wetland systems. W WATERSHED— The entire surface drainage area that contributes water to a lake or river. WATERSHED-SCALE APPROACH— A consideration of the entire watershed, including the land mass that drains into the aquatic ecosystem. WETLAND MITIGATION— Replacing wetland areas destroyed or impacted
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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy by proposed land disturbances with artificially created wetland areas. WETLANDS— Term for a broad group of wet habitats. Wetlands are lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water (Cowardin et al., 1979). Wetlands include features that are permanently wet, or intermittently water covered, such as swamps, marshes, bogs, muskegs, potholes, swales, glades, slashes, and overflow land of river valleys. According to the 1989 federal wetlands delineation manual, wetlands include lands saturated for at least 7 days to a depth of 12 inches. A newly proposed definition by the Bush Administration would be lands that have 15 days of standing water and 21 days of surface saturation. ENDNOTE 1. For extended discussion of functional attributes, see Cairns, J., Jr., and J. R. Pratt, eds. 1989. Functional Testing of Aquatic Biota for Estimating Hazards of Chemicals. Special Technical Publication 988. American Society for Testing and Materials, Philadelphia, Pa. 242 pp. For contrast with structural values, see Cairns, J., Jr., and J. R. Pratt. 1986. On the relation between structural and functional analyses of ecosystems. Environ. Toxicol. Chem. 5:785–786. REFERENCES Bhowmik, N. G., and J. B. Stall. 1979. Hydraulic Geometry and Carrying Capacity of Floodplains. Water Research Center, Research Report No. 145, University of Illinois, Urbana, 111. Chow, V.T. 1964. Handbook of Applied Hydrology: A Compendium of Water-resources Technology. McGraw-Hill Book Co., New York. Cowardin, L. M., V. Carter, F. C. Golet, and E. T. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. Office of Biological Services, U.S. Fish and Wildlife Service, U.S. Department of the Interior, Washington, D.C. Elwood, J. W., J. D. Newbold, R.V. O'Neill, and W. Van Winkle. 1983. Resource spiraling: An operational paradigm for analyzing lotic ecosystems. Pp. 3–27 in Thomas D. Fontaine III and Steven M. Bartell, eds., Dynamics of Lotic Ecosystems. Ann Arbor Science Publishers, Ann Arbor, Mich. 494 pp. Junk, W., P. B. Bayley, and R. E. Sparks. 1989. The flood pulse concept in river-floodplain systems. Proceedings of the International Large River Symposium (LARS). Canadian Special Publication of Fisheries and Aquatic Sciences 106:1110–127. Odum, E. P., J. T. Finn, and E. H. Franz. 1979. Perturbation theory and the subsidystress gradient. BioScience 34:558–562. Vannote, R. L., G. W. Minshall, K. W. Cummins, J. R. Sedell, and C. E. C. Cushing. 1980. The river continuum concept. Can. J. Fish. Aquat. Sci. 37:130–137. Ward, J. V., and J. A. Stanford. 1983. The serial discontinuity concept of lotic ecosystems. Pp. 29–42 in T. D. Fontaine III and S. M. Bartell, eds., Dynamics of Lotic Ecosystems. Ann Arbor Science Publishers, Ann Arbor, Mich. 494 pp.
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