ENVIR ST 360 1st EditionExam # 3 Study Guide Lectures: 13-19Lecture 13 (October 23) Difference Between Restoration and ConservationConservation Restoration- Maintaining biodiversity- Protecting habitats - Protecting rare species - Natural resource management- Replanting vegetation - Reintroducing species - Returning a site to a “natural” state(removing invasive species) Conservation tends to focus on big landscapes. It’s difficult to set aside large areas of land, but it’s highly beneficial because it creates big, intact landscapes where animals can exist. Examples: Everglades and Yellowstone Legislation has passed (Endangered Species Act) with the goal to conserve species and habitats. While there has been some success, most species have remained as endangered (only 30 delisted due to recovery) and some have gone extinct (10). How people prioritize ConservationRarityGenetic DiversityPotential for SuccessConservation Value Typically, the cuter animals are the ones who get saved The rate at which extinction is occurring is a problem; the exponentially growing human population correlates with the exponentially growing extinction rate. Because we’re to blame, maybe we should take action. Restoration ProjectsThe Shack: Aldo Leopold restored an old farm with prairie species and pines20,000 acres of prairie in northern Illinois: It was an old arsenal site, but people are planting seed sources to spread with the ultimate goal of a self-sustaining prairieEverglades Restoration: People are trying to get water flowing back into South Florida; It’s a 30 year, 8 billion dollar plan. Restoration ChallengesHow to prioritize?How long and how much money it will take? (These two are usually tied together)Lecture 14 (October 28) Wetlands are an Ecotone: Balance of land and water Wetland Disturbance Regime: Seasonal flooding can have a tremendous influence on the ecosystem Wetland HydrodynamicsWater SourceClimate Geologic FeaturesHydrological ResultsBiological OutcomePrecipitation Humid Poor drainage Waterlogged soils, anoxic conditions Low productivitySurface Flow Mesic tohumidRegular floodingInflux of nutrients High productivity, heterogeneous GroundwaterInfluxMesic Springs and seeps, permeable soilsGroundwater supplies nutrientsHigh productivity, Stable Ecosystem Services of Wetlands Shoreline Stabilization (Mangroves offer a lot of protection) Water Filtration Flood Mitigation Poyang Lake: Large conservation importance from Chinese government It is the key habitat for some migratory water birds Threats to Poyang Lake Habitat Fragmentation: Much disturbance in building a visitor center and planting non-native trees Population: Over 10 million people in Poyang Basin; produces a lot of air pollution Pollution: There are big heaps of trash at the edge of the lake which gets pulled into the lake when it rains Hydrological Alteration to Poyang Dredging: for sand Levees: for fish Dams: Energy Natural Hydrology of Poyang Connection with Yangtze River Dynamic flood-pulse ecosystem Winter dry season Summer wet season (with influx of sediments)Lecture 15 (October 30) Grassland: Ecosystem dominated by grasses and other herbaceous species Savanna: Widely spaced trees, groundcover is dense grasses Grazers: Past and present are important because they remove a lot of plant biomass and cycle nutrients back into the soil. They can be considered a disturbance that manipulates the ecosystem Carbon Cycle Much goes into plant cells: Trees or roots Fossil Fuels: In a long term process, the biomass gets packed down and turned into fossil fuels It gets released back into the atmosphere through wildfires or tapping into fossil fuelsLecture 16 (November 4) Grassland Grazing Animals: Modern day grazers are typically cows. This alters the ecosystembecause they behave differently than “natural” grazers; they stay in the same place which depletes resources and compacts the soil. Also their waste is different which affects the microbial community Carbon Storage in Grassland: Some is stored below ground in roots and soil. A lot gets storedinto charcoal because fire is so common. Grasslands in general are a huge carbon sink. Challenges in Conservation and Restoration of Grasslands There is a focus on other ecosystems It’s difficult to set fires It’s difficult to find and remove invasive grasses and trees Often they’re converted for agricultural use. After this is done, it’s difficult to get native plants to grow again. Woodland and Forest General Characteristics Both are tree dominated ecosystems Difference between a woodland and a forest is canopy cover Woodlands have less densely packed trees Forests have high tree density, little light reaches the ground- One way to think about this is how much light can reach the ground. In woodlands, there are more grasses and forbs because light can get through. In forests, there’s a canopy that blocks sunlight and limits the amount of life that can grow on the ground, so you don’t have a big grass component. Forest ecosystems are highly variable: Different types can have different species, nutrient cycles and structures Tropical Rain Forest: Difference in temperature and soil and nutrient cycles. Tropical plants are different Boreal Forest: Typically pine dominated with a lot of precipitation in the form of snow and cooler temperatures. Infrequent disturbances with high tree density Tree Farms (Linear Planting of Trees) do not constitute a forest: they lack the proper structure Structure Four Layers Emergent Layer (tallest trees) Canopy layer (where you get the interception of light. Most leaves are at this level). Understory layer (these are trees waiting for an opportunity to get into the canopy) Forest Floor (tropical systems may have more species, but some of your hardwood forest will be mostly just leaf litter due to the decrease in sunlight) Sunlight and temperature decrease as you move down the layers Often, different species are adapted to different layers Human Impacts Deforestation Can move to more sustainable practices than clear cutting. You can try to do uneven age structures of trees Recreation Ski lifts and trails can create hydrology problems, erosive problems and invasive speciesLecture 17 (November 6)
View Full Document