Wetland Definitions & Hydrology (PDF)

1. Articulate the common, legal and ecological definitions for wetlands Common - pond, area thats wet, collects water and is ponded/soggy more often than not, saturated with water, low-lying area saturated with water permanently or seasonally Legal definitions emphasize - specific precise...

1. Articulate the common, legal and ecological definitions for wetlands Common - pond, area thats wet, collects water and is ponded/soggy more often than not, saturated with water, low-lying area saturated with water permanently or seasonally Legal definitions emphasize - specific precise criteria, clarity, exclusivity Ecological definitions emphasize - flexibility, rigor, and inclusivity All include presence of water, hydric soils, and hydrophytic vegetation 2. Explain the importance of wetlands to natural systems and humans Water quality improvement, wildlife habitat, fish habitat, flood mitigation, erosion reduction, cultural and spiritual significance, climate change mitigation, groundwater recharge or discharge, recreation and tourism, source of food and medicines 3. Describe the main types of wetlands and their distinguishing features a) Bog group - ombrotrophic, peatland, species poor-lots of sphagnum moss, extremely acidic (pH 6, saturated peat and marl soils very deep c) Forested wetland group - variable water and nutrient source, some are peatlands, species-variable due to soils, landform, pH, but dominated by trees, acidic to alkaline, organic and mineral soils shallow to deep and seasonally inundated d) Marsh group - variable water and nutrient source, decomposing soils (not peatlands), species-rich due to hydrology, soils, fire but dominated by herbaceous plants, neutral to alkaline, organic soils moderate to deep, inundated to saturated e) Shrub wetland group - variable water and nutrient source, peatlands, species poor to rich depending on hydrology, soils and landscape, dominated by tall shrubs, neutral to alkaline, organic or mineral soils of variable depth and inundated to saturated f) Wet prairie group - variable water and nutrient source, not peatland, species rich due to hydrology and fire, dominated by grasses, neutral pH, organic soils that are shallow and seasonally inundated to saturated g) Wooded dune … swale … complex - unique to Great Lakes community, formed by retreating water and post glacial uplift, can extend up to 2 miles inland, upland and wetland types change with distance from lake, streamflow and groundwater - waves/lake flooding, some peatlands, species richness increases with distance from lake due to hydrology and succession, dominance varies with distance, variable pH, variable soils with calcareous sands Definitions Ombrotrophic - all water and nutrients from precipitation Minerotrophic - water and nutrients primarily through ground water and surface flow Variable water and nutrient sources - groundwater, flooding, precipitation Peatland - wetland that naturally accumulates plant matter and prevents decomposition Marl - mixture of sedimentary rock, calcium carbonate, clay Calcareous sands - deep peat or marl 4. Describe the role of wetlands in historical civilizations and indigenous cultures Wetlands allowed people to create irrigation systems, which then allowed for firsts in farming/agriculture. Very revolutionary. ???? 5. Describe the magnitude and trends of wetland loss over historical periods, emphasizing the scale and significance of these losses in global and regional contexts. Half of OG wetlands in US and Europe gone, 25-50% lost globally. Big loss in 1950s-1970s but have decreased since. ???? 6. Identify and discuss the primary anthropogenic drivers of historical wetland loss Conversion of wetlands have taken place so they no longer serve “original” functions. Wetland loss (40%) in MI due to settlement, but overall driven by urbanization and agriculture causing fisheries declines, water quality declines, flooding and habitat loss. Loss rate has decreased 7. Discuss historical conservation efforts and policies aimed at mitigating wetland loss ???? 8. Define key hydrological terms and concepts Hydrology - timing, extent, and movement of water in and out of a wetland ecosystem Terrestrialization - sediments and organic matter decompose to form soils which build up, low water holding capacity Peat formation - sediments and organic matter build up do not decompose, high water holding capacity Hydroperiod - seasonal pattern of water level of a wetland; hydraulic signature; characterizes wetland type; types: permanently flooded, seasonally flooded, intermittently flooded, flood duration, flood frequency, flashy (comes in and leaves fast) 9. List and explain the main drivers of wetland hydrology Climate - wetlands more common in cold and water climates due to reduced evapotranspiration (cool areas), excess precipitation (wet areas) Geomorphology - wetlands more common in flat - gently sloping landscapes Physiochemical environment - wetland sediments, soils, and chemistry can modify hydrology, soil types and depths influence water input and retention; terrestrialization and peat formation Biota - reflection of all the drivers and hydrology, modifies physicochemical and hydrology, microbes and fungi catalyze reactions, control nutrient availability, generate phytotoxins, contribute extensively to decomposition, plants produce structure and shade, trap sediments, build peat, retain and transform nutrients, retain and move water as well as carbon dioxide and oxygen, animals move vegetation, physically alter habitats and cycle nutrients 10. Explain how wetland hydrology influences the types, biodiversity, and ecological functions of wetlands Hydrology is dynamic, each wetland has different hydroperiod - varies by month, as well as year to year fluctuations. The surrounding environment has to adapt and thus be able to withstand these ~frequent~ changes. Slows and stores water to prevent flooding