Resource Management 2 Lecture 6 (Part 4) Notes for 2024.pdf

Resource Management 2 (Lecture 6: Part 4) Cowardin Wetland Classification Lacustrine Wetland Systems  Lacustrine Wetland Systems  The lacustrine wetland system, according to the Cowardin classification, encompasses all wetlands and deepwater habitats situated in natural or artific...

Resource Management 2 (Lecture 6: Part 4) Cowardin Wetland Classification Lacustrine Wetland Systems  Lacustrine Wetland Systems  The lacustrine wetland system, according to the Cowardin classification, encompasses all wetlands and deepwater habitats situated in natural or artificial lakes, reservoirs and other inland water bodies that are large enough to be classified as lacustrine  This system is distinguished by its non-flowing water bodies, which are usually deep and possess extensive open water areas  The Lacustrine Wetland System includes the following general characteristics The lacustrine wetland systems includes wetlands and deepwater habitats within a topographic depression or dammed river channel and may be tidal or nontidal The salinity is typically less than 0.5 ppt, although some systems may have higher salinity levels Situated in water bodies greater than 8 hectares (20 acres) in size or having a fetch (the distance across the open water) greater than 500 meters (1 640 feet) Lacking trees, shrubs, persistent emergents, emergent mosses or lichens and having a less than 30% coverage Although lacustrine wetland systems may have fringing vegetation, the majority of the wetland area is open water Areas less than 8 hectares (20 acres) may be included in the Lacustrine Wetland System only if An active wave-formed or bedrock shoreline feature makes up all or part of the boundary The water depth in the deepest part of the basin exceeds 2 m (6.6 feet) at low water Lacustrine Wetland Systems Lacustrine Wetland Systems  Boundaries of Lacustrine Wetland Systems  The Cowardin classification system defines the boundaries or limits of lacustrine wetland systems based on specific criteria related to size, depth, vegetation and other physical characteristics  These boundaries are crucial for accurately identifying, classifying and managing these wetland systems  These boundaries delineate the extent of lacustrine wetland systems and are crucial for understanding their ecological dynamics and management  These boundaries are critical for the conservation, management and study of lacustrine wetland systems, ensuring their ecological integrity and sustainability  Boundaries of Lacustrine Wetland Systems Size and Area Boundary Lacustrine wetland systems include water bodies that are larger than 8 hectares (20 acres) in size This criterion ensures that only substantial bodies of water are classified as lacustrine wetland systems A water body can also be classified as lacustrine if it has a fetch (the distance across open water) greater than 500 meters (1 640 feet), even if the total area is less than 8 hectares This criterion captures smaller, but still significant, water bodies with considerable open water surface area Depth Boundary Lacustrine wetlands are characterized by water depths greater than 2 meters (6.6 feet) at low water This depth criterion distinguishes lacustrine wetland systems from shallower wetland types, such as palustrine wetland systems  Boundaries of Lacustrine Wetland Systems Water Level Lacustrine wetland systems are influenced by standing or slow moving water that is deeper and more stable compared to riverine or palustrine wetland systems The boundary is often defined by the ordinary high water mark, which can be identified by physical characteristics such as natural lines on the shore, changes in soil composition and the presence of certain types of vegetation The lower boundary is marked by the depth criterion, where water is deeper than 2 meters at its lowest level Shoreline Boundary The shoreline is typically well-defined and includes features such as beaches, cliffs or gradual slopes leading into deeper waters The boundary often follows the natural topographic features of the lacustrine wetland systems shoreline, which can include beaches, cliffs and gradually sloping banks The boundary often extends to the outer edge of the wetland vegetation or to the top of the bank or shore  Boundaries of Lacustrine Wetland Systems Vegetation Boundary Lacustrine wetland systems typically lack persistent emergent vegetation (plants that stand above the water surface throughout the year) in their central open water areas This helps differentiate them from palustrine wetland systems, which often have dense emergent vegetation The shallow edges (littoral zones) of the lacustrine wetland systems may have the presence of non-persistent emergents, submerged vegetation or floating leaved aquatic plants In deeper standing waters, algae, phytoplankton and aquatic macrophytes may be present Dams and Impoundments Boundary Human-made lakes or reservoirs created by damming rivers or streams are included if they meet the size and depth criteria for lacustrine systems Boundaries for these artificial systems are defined by the constructed edges of the waterbody and its impoundment infrastructure These structures can expand or restrict the natural extent of the lacustrine wetland systems  Ecotones of Lacustrine Wetland Systems Ecotones in lacustrine wetland systems are transition zones where freshwater lakes and surrounding terrestrial ecosystems meet, creating diverse and ecologically significant habitats Lacustrine wetlands encompass a variety of habitats, including lake shores, wet meadows and shallow water zones, and support a wide range of plant and animal species Ecotones within these systems play important roles in nutrient cycling, habitat provision and shoreline stability Protecting and conserving these transition areas is essential for maintaining the health and resilience of lacustrine ecosystems in the face of environmental changes Littoral Zone Ecotone The littoral zone is the shallow-water area near the shore of a lake, where light penetrates to the bottom and supports aquatic plant growth This ecotone zone is characterized by emergent vegetation which provide important habitat for fish, amphibians and invertebrates The littoral zone also serves as a spawning ground for many fish species and a feeding area for waterfowl and other wildlife  Ecotones of Lacustrine Wetland Systems Riparian Zone Ecotone The riparian zone is the area of land adjacent to the lake shore, influenced by the presence of water and periodic flooding This ecotone zone is characterized by a mix of wetland and upland vegetation Riparian zones provide important habitat for birds, mammals and amphibians, as well as, serving as a buffer against erosion and sedimentation Wet Meadow Ecotone Wet meadows are transitional habitats between open water and upland areas, characterized by shallow water tables and seasonally saturated soils This ecotone zone supports a diverse array of wetland plants, as well as, a variety of wildlife species adapted to wetland conditions Wet meadows play important roles in water filtration, flood attenuation and carbon sequestration Open Water-Lake Shore Ecotone Along the edges of lakes, the open water-lake shore ecotone is formed, where shallow water transitions to deeper water This ecotone zone supports a mix of aquatic and terrestrial species, including fish, waterfowl and shoreline vegetation It provides important habitat for spawning and nursery areas for fish, as well as, nesting and foraging areas for birds  Ecotones of Lacustrine Wetland Systems Floating Vegetation Ecotone In some lacustrine wetland systems, floating vegetation mats form along the edges of lakes, creating unique habitats for aquatic and semi-aquatic species These mats may consist of floating plants which provide cover and food for fish, amphibians and invertebrates Floating vegetation ecotones also help stabilize shorelines and filter nutrients from the water  Factors influencing Boundaries of Lacustrine Wetland Systems Seasonal Variability In many lacustrine wetland systems, water levels rise and fall with the seasons For instance, in temperate regions, snowmelt in the spring can significantly raise water levels, expanding the lacustrine boundary Conversely, during dry summer months, water levels may drop, contracting the boundary Climate and Weather Events Extended droughts can significantly lower water levels, reducing the extent of the lacustrine wetland system On the other hand, heavy rainfall and flooding can increase water levels and expand the boundaries Human Activities Activities such as dam construction, water withdrawal for irrigation and urban development can alter the size and shape of lacustrine wetland systems Reservoirs are managed for water supply and their water levels and boundaries can vary widely based on human demands and water management policies In some areas, land reclamation projects can reduce the size of lacustrine wetland systems by draining parts of the lake or filling in shallow areas for development  Factors influencing Boundaries of Lacustrine Wetland Systems Geomorphological Changes Natural processes such as erosion and sediment deposition can change the boundaries of lacustrine wetland systems Erosion can carve out new areas, while sedimentation can fill in parts of a lake, altering its shape and size over time Biological Factors The extent of emergent and submergent vegetation can influence the boundaries of the littoral zone of lacustrine wetland system Seasonal growth and decline of plants can cause the boundaries to expand or contract Dense growth of aquatic plants during the growing season can extend the littoral boundary into deeper water  Accurate Delineation of Lacustrine Wetland System Boundaries is crucial for several reasons Ecological and Environmental Importance Lacustrine wetland systems provide essential habitats for a wide variety of aquatic and terrestrial species. Accurate boundaries ensure that these habitats are identified and protected, supporting biodiversity. Proper delineation helps in the management of species that rely on these wetlands for breeding, feeding and shelter. Accurate boundaries help in monitoring and controlling the sources of pollution entering the wetlands. This is vital for maintaining the water quality of the lakes and surrounding wetlands. Lacustrine wetland systems play a key role in nutrient cycling, including nitrogen and phosphorus. Proper delineation ensures that the areas performing these ecological services are protected and managed. Lacustrine wetland systems act as natural buffers by absorbing excess rainfall and reducing flood impacts. Accurate boundary delineation is crucial for understanding and managing these hydrological functions. Delineation helps in identifying areas that contribute to groundwater recharge, ensuring sustainable water management practices.  Accurate Delineation of Lacustrine Wetland System Boundaries is crucial for several reasons Regulatory and Legal Compliance Accurate boundaries are necessary to comply with national and international wetland protection laws. Clear boundaries facilitate the issuance of permits for activities such as development, agriculture and industrial operations, ensuring that they do not encroach on protected wetland areas. Accurate delineation informs zoning regulations and guides sustainable development practices. It helps planners and developers avoid environmentally sensitive areas and reduces the risk of legal disputes. Environmental Impact Assessments (EIAs) rely on precise boundary information to assess the potential impacts of proposed projects on lacustrine wetland systems, ensuring that mitigation measures are appropriately designed and implemented.  Accurate Delineation of Lacustrine Wetland System Boundaries is crucial for several reasons Resource Management Proper delineation of lacustrine wetland systems supports the sustainable management of fisheries by ensuring that critical spawning and nursery habitats are protected. Accurate boundaries help in managing wildlife populations and their habitats, supporting conservation programs and initiatives. Lacustrine wetland systems often serve as sources of water for irrigation and drinking. Accurate boundaries ensure that water extraction practices are sustainable and do not harm the ecological integrity of the wetlands. Managing recreational activities such as boating, fishing and tourism relies on knowing the exact boundaries to prevent ecological degradation and ensure safety.  Accurate Delineation of Lacustrine Wetland System Boundaries is crucial for several reasons Conservation and Restoration Accurate delineation of lacustrine wetland systems allows for the identification and prioritization of critical areas for conservation efforts, ensuring that resources are effectively allocated. Successful wetland restoration projects depend on precise boundary information to restore natural hydrology, vegetation and wildlife habitats. Boundaries that reflect current conditions enable ongoing monitoring and adaptive management practices. This is important for responding to changes such as climate change impacts, invasive species and other ecological pressures. Research and Monitoring Accurate boundaries provide baseline data for ecological studies, allowing researchers to assess changes over time and understand ecological processes. Long-term environmental monitoring programs rely on consistent and precise boundary delineation to track changes in wetland extent, health and function. Accurate and standardized boundary information facilitates data collection and analysis, enabling comparisons across different studies and geographic areas. Precise boundaries support predictive modeling efforts that assess the impacts of environmental changes and human activities on lacustrine wetland systems. Subsystems of Lacustrine Systems Limnetic All deepwater habitats within the Lacustrine System; 01 many small Lacustrine Systems have no Limnetic Subsystem Littoral All wetland habitats in the Lacustrine System 02 Extends from the shoreward boundary of the system to a depth of 2 m (6.6 feet) below low water To the maximum extent of nonpersistent emergents, if these grow at depths greater than 2 m  Classes of Lacustrine Systems  Rock Bottom, Unconsolidated Bottom, Aquatic Bed, Rocky Shore, Unconsolidated Shore and Emergent Wetland (nonpersistent) Distinguishing features and examples of habitats in lacustrine wetland systems. Source: Cowardin et al. (1979)  Ecological Significance of Lacustrine Wetland Systems Biodiversity Hotspots Lacustrine wetland systems support diverse ecosystems and harbor a wide variety of plant and animal species Lakes and their associated wetlands provide habitats for aquatic organisms such as fish, amphibians, reptiles, invertebrates and aquatic plants Additionally, the surrounding riparian zones and wetland habitats support terrestrial species, including mammals, birds and insects The diverse habitats within lacustrine systems contribute to high levels of biodiversity and serve as important refuges for many species Habitat for Endemic and Threatened Species Lacustrine wetlands often harbor endemic species that are found nowhere else, as well as, populations of threatened and endangered species These habitats provide critical breeding, feeding and nesting grounds for species with specialized ecological requirements Protection and restoration of lacustrine wetlands are essential for conserving these unique and vulnerable species and maintaining overall biodiversity  Ecological Significance of Lacustrine Wetland Systems Nutrient Cycling and Water Quality Lacustrine wetlands play a crucial role in nutrient cycling and water quality maintenance They act as sinks for nutrients such as nitrogen and phosphorus, which are essential for plant growth but can lead to eutrophication and water quality degradation when present in excess Wetland vegetation and soils help absorb and trap these nutrients, preventing them from entering the water column and reducing the risk of algal blooms and oxygen depletion Carbon Sequestration and Storage Lacustrine wetland systems contribute to global carbon cycling by sequestering and storing carbon in vegetation, soil and sediments Aquatic plants capture carbon dioxide from the atmosphere through photosynthesis, incorporating carbon into biomass This carbon storage helps mitigate climate change by removing carbon dioxide from the atmosphere and reducing greenhouse gas emissions  Ecological Significance of Lacustrine Wetland Systems Hydrological Regulation and Flood Control Lacustrine wetlands play a crucial role in regulating the hydrological cycle and mitigating the impacts of floods and droughts Lakes act as natural reservoirs, storing water during periods of high precipitation and releasing it gradually during dry periods Wetlands surrounding lakes help absorb excess water during floods, reducing peak flows and preventing downstream flooding These wetlands also recharge groundwater and maintain base flow in rivers and streams during dry periods, ensuring water availability for ecosystems and human communities Shoreline Stabilization and Erosion Control Lacustrine wetland systems provide important shoreline stabilization and erosion control services Vegetation along lake shores helps bind soil and stabilize banks, reducing erosion caused by waves and currents Wetland vegetation also acts as a buffer, dissipating wave energy and protecting adjacent coastal areas from erosion and sedimentation Healthy lacustrine wetlands contribute to the resilience of ecosystems and provide habitat for various biota  Ecological Significance of Lacustrine Wetland Systems Cultural and Recreational Values Lacustrine wetland systems hold cultural and recreational significance for communities These ecosystems provide opportunities for fishing, boating, swimming, birdwatching, hiking and other outdoor activities, enhancing the quality of life for residents and attracting tourists Additionally, lakes often have cultural importance for indigenous communities, who may rely on them for food, water, transportation and spiritual connection