Unit 2 Study Guide ENVIRON 102 PDF

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This is a complete study guide for ENVIRON 102's second exam. ...

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Unit 2 Study Guide Numbers ● 2 degrees Celsius ● 565 Gigatons of CO2 that can be emitted and still stay under 2 degrees ● 2,795 Gigatons of CO2 that would be emitted if fossil fuel companies use the resources that they have either in underground storage, or invested in. 10/4/17 Notes Class 12 Notes ● Night Lights of San Juan. Before and after the hurricane ○ Are there other contaminated areas? ○ Hurricanes are natural disturbance that change in frequency and intensity. Tropical forest ecosystems are adapted to hurricanes ○ Long term data shows this hurricane is strongest they’ve ever seen. The intensity has increased greatly. Also, invasive species are there which makes natural succession harder to take place. ● Case Study #2: Agriculture and Environmental Justice (Hog farming in NC) ○ Agriculture: impacts on ecosystem and human health ○ Local focus but broader lessons ○ Environmental justice case study ● Nutrient cycles, and soil ● Biomes - determined by temperature and precipitation ● Some ecosystems are more productive or easier manipulated to grow more food

● ● Permaculture is more diverse

● Monoculture is not robust ● Growing region varies in ○ Inputs ○ Outputs ■ Many outputs in Corn field and CAFO ○ Species RIchness ○ Functions ■ Midwest Corn Field: Some habitats, food production, Photosynthesis ■ NC Organic Field: Amend soil, seasonal pollination, seasonal habitat ■ CAFO: fertilizer ■ Permaculture: hold soil, habitat, photosynthesis. ● Environmental issues ○ Soil Erosion ○ Water Use ○ Nutrients: Fertilization and eutrophication ○ Pesticides: Competition and contamination ○ Energy costs/ emissions ● Land Transformation ○ 30% of ice-free land converted to agriculture ○ Humans use 30% of net terrestrial primary productivity for food and fiber production ○ 50% of world’s topsoil lost ● Strategies to prevent soil erosion ■ Crop rotation - change where you plant ■ Intercropping - grow crops together ■ No-till farming cover crop - change the way the land is processed after harvest ■ Contour farming - attempts to hold down soil ■ Terracing ■ Shelterbelts ○ Different methods applicable in different areas ● USDA Conservation Reserve Program ○ Pays farmers not to use most vulnerable land ○ Uses riparian buffers ● Issue #2: ○ 70% of all freshwater used by humans is used for irrigation ○ Many aquifers are being depleted quickly; salination, desertification ○ Conventional irrigation ○ Drip Irrigation

● Green Revolution ○ Norman Borlaug (1960s peace prize) ○ Agricultural Intensification ○ Food increased, but land and seed use stayed the same ○ http://www.nationalgeographic. com/food features/green- revolution/ ● Green Revolution - Fertilizers ○ Nitrogen additions to the biosphere by humans 140 x 109 Kg/yr ■ Industrial Fixation (fertilizer manufacture) 80 x 109 Kg/yr ■ Legume crops 40 x 109 Kg/yr ■ Fossil fuels 20 x 109 Kg/yr ○ What’s happening to the excess? ■ Increased productivity and N-storage in plants ■ Increased flux in rivers – flux in rivers has increased 2 to 20 fold over past half century ■ Transformation of atmospheric chemistry -- NOx ● Biocides: contamination of water, soil, food ○ Highly persistent ○ Neonicotinoids and bees ○ EWG’s Dirty Dozen ● Biomagnification ○ How small amounts of a chemical ends up in higher forms of life ○ Small life absorbed chemicals, next level eats way more of the small, and on and on ● Integrated Pest Management (IPM) ○ Biocontrol ○ Pesticides ○ Close population monitoring ○ Habitat modification ○ Crop Rotation ○ Transgenic crops ○ Alternative tillage ○ Mechanical pest removal ● Agriculture in NC ○ 1800s: Cotton/Timber → 1900s: Cotton/Tobacco/Timber → Today: Tobacco/Sweet Potatoes/ Pork/ Poultry/ Christmas Trees ● Factory farms at a glance ○ 9 times as many chickens as people ○ 9.3 million hogs, 9.4 million peoples

○ 2.2 million hogs in Duplin County = produces the same amount of sewage from NYC each day ● October 11, 2016: Flooding in eastern NC ○ Hogs killed ○ Complete flooding of sewage

● ● China has stricter environmental laws than NC does ● How nutrient cycles should work. How we interfere with that. Fertilizers and fallout: agriculture today and what happens when it fails ● Wrap up agriculture overview ● Wander through water cycling, carbon briefly, nitrogen, and phosphorous ● After agriculture: Old field succession in NC ● Major impacts of agriculture ○ Biodiversity loss ○ Water waste and pollution, ○ air pollution, air qual probes ○ Soil erosion Zach’s Lecture 10/04/17 ● Soil erosion ○ What causes it? ○ Loss of stabilizing roots ○ Damaged soil structure ○ Wind - “Dust Bowl” ○ Flowing water ■ Excess water not utilized by plants ■ Sometimes this is due to the change in the vegetation community: Forests and even grasslands transpire more water than most agricultural fields

● Water Cycle ○ What goes up must come down ● Carbon Cycle Flows ○ SUnlight provides the energy for C-fixation/reduction (aka photosynthesis ○ Everything after photosynthesis is basically organic C being oxidized and broken down ○ Cycle generally goes: Precipitation → surface/subsurface flow + Evapotranspiration → Oceans (repeat)

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■ The importance of ET ○ Evapotranspiration (ET) – this is the link between water and carbon through photosynthesis ○ As plants open the stomata in their leaves to fix carbon (photosynthesis), they also release water vapor which has been drawn up through their roots and release it into the atmosphere Carbon cycle flows ○ Sunlight provides the energy for C- fixation /reduction (aka photosynthesis) ○ Everything after photosynthesis is basically organic C being oxidized and broken down Annual cycles, CO2, and vegetation ○ Mauna loa observatory is (in)famous for tracking the amazing rise in CO2 through time. ○ Today though we are going to zoom in on the seasonal fluctuation of CO2 ○ When global carbon fixation (photosynthesis) > decomposition & respiration: atmospheric CO2 drops in our spring/summer due to large northern hemisphere forests ○ The global atmospheric trend then reverses in our fall/winter months when there is more net carbon decomposition & respiration and atmospheric co2 increases What about the soil atmosphere??

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○ Soil is a 3-phase system made of solids, liquids, and gasses ○ Ag would be impossible without soil Below ground CO2 ○ Surface vegetation affects below ground environment ○ Atmospheric and. soil CO2 are inversely synchronized ○ When plants or forests “breathe in” they draw CO2 out of the air What happens if you remove the native vegetation to establish agriculture? ○ Let's look at EV and surface flow ○ We will return to CO2 later ○ Deforestation experiment from hubbard brook experimental forest ○ ET decreases when you remove the native vegetation there is leftover water in the budget ○ The water has to go somewhere and generally ends up flowing off the land, taking soil with it Harmful effects of soil erosion ○ Harmful effects ■ Soil fertility declines ■ Water pollution occurs ■ Agricultural land in the tropics and subtropics has and continues to be abandoned do to extensive soil erosion Review ○ Who can explain why global atmospheric CO2 rises and falls annually? ○ Is there generally more water flowing off of an area before, or after conversion to agriculture? Why? ■ Vegetation isn't holding soil in place ■ Water isnt take up in transpiration ○ What is a consequence of this? ■ Soil erosion Reduce Soil Erosion (types of farming) ○ Terracing ○ Contour plowing ○ Alley cropping ○ Windbreaks Reduce Soil Erosion ○ Conservation-tillage farming ○ No-till farming ○ Minimum-tillage farming ○ Retire erosion hotspots Restoring Soil Fertility

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○ Organic fertilizers ■ Animal manure ■ Green manure ■ Compost ○ Crop rotation uses legumes to restore nutrients ○ Inorganic fertilizers - runoff pollution problem Industrialized Food Production Requires Huge Energy and Fertilizer Inputs ○ Mostly non renewable to: ■ Run machinery ■ Irrigation ■ Produce pesticides ■ Process foods ■ Transport foods How far do you think food in the U.S. from farm to plate? ○ 1300 miles ○ This is why “local food” can have such amazing environmental benefits Why fertilize? ○ Plants need nutrients to grow and reproduce ○ “Conventional” agriculture extracts more nutrients from the soil than generally sustainable ○ Because soil erosion is such a problem there is often a large amount of nutrients (like Nitrogen and Phosphorous), that get washed out of fields with soil ○ And so, farmers have to either change management practices (hard and initially expensive Nitrogen Cycle ○ Huge atmospheric pool: ~80% N2, most of it is inaccessible to life ■ Because of three covalent bonds ○ N-nixer example: Azotobacter and legumes ○ Anoxic decomposition, with N - compounds present often leads to N2O GHG emissions Haber-Bosch: synthetic N-fertilizer ○ Haber bosch and the “green” revolution shortcut n-fixers and flooded the worlds with cheap n-fertilizers ■ Ammonium fertilizers didn’t bind to soil well ■ Often gets washed away! Phosphorous cycle ○ Phosphorous comes from rocks ○ We’s mixed P at an extraordinary rate ○ Morocco controls the worlds P with an estimated of 75% of reserves!

● Phosphorous vs. time ○ Ecosystem trajectories: early vs. late successional ○ Phosphorous is tightly recycled in the environment but still lost gradually ○ Amazon-Sahara fertilization ○ Initally, P is mostly coming from new rock sources. Eventually the rock/soil sources of P are diminished. From this point on, P must either be recycled by biota, or added externally (fertilizer) ● Phosphorous pollution ○ Phosphorous pollution mainly linked to erosive agriculture ○ Phosphorous usually tightly held by soils but acidification (e.g. NH3 fertilizer) can reduce this ● Pause ○ How can local food be beneficial environmentally speaking? ○ When is phosphorous mostly tied up in biological material: early or late successional? ○ The invention of what process made N-fertilizers hugely available world-wide? ● Agricultural Abandonment ○ What happens when agriculture fails? ○ Sometimes people can’t (or don’t try to) prevent erosion and have to abandon their fields ● Agricultural impacts on soil in the Carolinas ○ SHTF in the SE US after ~200 years of erosive   agriculture ○ ~18 cm of soil was lost across this entire region, millions of tons of soil ● Land-use and land cover change in the Carolinas ○ Pre-colonial hardwoods → deforestation and agriculture → extreme erosion by the 1930’s and 50’s → major reforestation 1960’s now dominated by pines ● Old-field succession conclusion: soil respiration ○ There has been an amazing amount of above and below ground regeneration in secondary old-field forests in the SE US. ○ Even after 80-100 years though, there are still strong differences in these systems which have not fully recovered ○ One obvious difference lies in the rooting patterns of these systems:

■ ● Synthesis ○ Water flows through and interacts with all of the processes mentioned today ○ Management and mismanagement of agricultural lands can and does have huge repercussions around the world for decades to hundreds of years ○ There is much we can learn about current and past agricultural systems right here in our area. 10/4/17 Readings ● Chapter 12 ● Llano Estacado in NM and Texas has irrigated farms and ranches. It used to be only a praire with sod that protected from erosion. Now over 90% plants that eroded the sod and showed the mineral soil which lead to extreme drought. Rapid growth of human populations over the past century is directly related to the increased availability of food. Ag ecosystems are fragile ● Agriculture - system of land management used to grow domesticated plants and animals for food, fiber, or energy ● Hunter gathers were actually healthier and taller but agriculture provides for larger communities ● 10000 years ago - wheat, peas, lentils, and chickpeas in middle east ● 12000 years ago humans began to domesticate animals to help hunt ○ Domestic animals mature quickly, able to eat a wide variety of foods, breed in captivity ● Wheeled plows, water pumping devices, dams, and reservoirs allowed for the exploitation of more land ● 1400-1700: crops came from europe and asia like potatoes and tomatoes ● Crop rotation sustains productivity because legumes fix nitrogen from the air, restoring nitrogen to soils that have been depleted by harvest

● Agronomy- science that applies to knowledge of fields such as genetics, physiology ● Green revolution - increased global agricultural productivity due to fertilizers, herbicides, Pesticides. But led to increased fossil fuel use as well as runoff of nitrogen and chemicals into aquatic systems which altered nutrient cycles and depleted natural resources ● Humans make up less than 1% of earth’s biomass but use more than 30% of earth’s terrestrial net primary production ● Agroecosystem - ecosystem that includes crops and domestic animals, the physical environments in which they grown, and the communities of other organisms associated. ○ Farmers strive to optimize growth of a single species and limit growth of other species that compete - leads to loss of biodiversity ● Photosynthesis converts solar energy to chemical energy of carbs ● Harvest index - fraction of total production that can be used by people ○ Ex: for corn its 30-50% because you can’t eat roots or stems ● Trophic level efficiency - fraction of energy the animal consumes that is actually stored as biomass - less than 10% for wild animals due to selective breeding, 40% for domesticated ● Agriculture originated independently in several places as a consequence of climate change, cultural progress, and human population growth ● Humans, crop plants, and domestic animals have coevolved ● Agricultural ecosystems depend on energy flow and nutrient cycling following the same principles as natural ecosystems ● Plant growth and reproduction depend on adequate light, water, and nutrients ● Soil structure, organic matter, and nutrient content influence the growth of crop plants ● Differences in range of tolerance for environmental factors determine when and where different crop plants grow best ● Unlike natural ecosystems, agroecosystems lack processes to sustain soil fertility ● Soil conservation practices include limiting soil exposure and disturbance as well as diversifying crops ● Soil texture and organic matter determine the amount of water that a soil can hold against the force of gravity ● Irrigation has allowed expansion of agriculture in arid regions but it creates important environmental challenges ● Domesticated animals in agroecosystems present several environmental challenges, including land for food and range, waste disposal, and disease ● Selective breeding, cloning, and genetic engineering have produced very productive strains of domestic plants and animals, but they have also diminished genetic diversity ● Pesticides are used to control populations of weeds, pests, and disease organisms that compete for the food in agroecosystems

● The ecological impacts of our eating habits are determined by whether our diet emphasizes plants or meat, how our food is grown, and where our food comes from ● Chronic hunger affects more than 10% of earth’s people even though global food production is sufficient to feed everyone ● Nitrogen fixation - process that converts nitrogen gas (n2) to ammonia (nh3) ● Denitrifcation - nitrogen in soil and water is returned to the atmosphere ● Haber-bosch process- nonbiological method of nitrogen fixation ● Intercropping - alternating bands of different crops in the same field, binds soil particles in place between the primary crop rows ● Terracing - cutting a series of wide steps into the slope, helps to retain water and limit runoff in sites that would otherwise be very difficult to cultivate ● Contour farming - plowing along the contour of the land ● Monoculture - plantings of a single crop species ● Polyculture - practice of planting multiple crop species in the same field ● Biomagnification - process by which the concentration of a pesticide increases through a food chain 10/11/17 ● King Corn ○ Two recent college graduates travel to Iowa to investigate the role that corn plays in an increasingly complicated and dysfunctional American food industry. After planting their own small crop of corn and tracing its journey through the industry, they are alarmed to discover that corn figures in almost everything Americans eat. The consequences of this are examined through interviews with various experts and industry insiders, providing a balanced look at this American agricultural issue. ● Cowspiracy ○ Cowspiracy: The Sustainability Secret  is a groundbreaking feature-length environmental documentary following intrepid filmmaker Kip Andersen as he uncovers the most destructive industry facing the planet today – and investigates why the world’s leading environmental organizations are too afraid to talk about it. ○ Animal agriculture is the leading cause of deforestation, water consumption and pollution, is responsible for more greenhouse gases than the transportation industry, and is a primary driver of rainforest destruction, species extinction, habitat loss, topsoil erosion, ocean “dead zones,” and virtually every other environmental ill. Yet it goes on, almost entirely unchallenged. ○ As Andersen approaches leaders in the environmental movement, he increasingly uncovers what appears to be an intentional refusal to discuss the issue of animal

agriculture, while industry whistleblowers and watchdogs warn him of the risks to his freedom and even his life if he dares to persist. ○ As eye-opening as Blackfish and as inspiring as An Inconvenient Truth , this shocking yet humorous documentary reveals the absolutely devastating environmental impact large-scale factory farming has on our planet, and offers a path to global sustainability for a growing population. 10/16/17  nvironmental Working Group ● Read this background report from the E ○ Nc = 2nd biggest hog farming industry worth 3 billion in 2012 ■ 3rd among states for poultry production ○ Nc swine population doubled in 2 decades and has 9.5 million in 2012 ○ Chicken production is at 128 million animals ○ Many great financial benefits ○ 10 billion gallons of wet animal waste produced each year in nc ■ 15000 olympic size swimming pools according to waterkeeper alliance ○ 200 million birds create 2 million tons of dry waste per year ○ Leads to air and water quality problems especially in duplin and sampson counties ○ Poultry housed in cafo facilities outnumber residents by 20 to 1 ○ Nc environmental justice network states lax regulation of hog waste disposal affects communities of color in rural areas ○ Farmers use the bacteria laden animal waste as fertilizer or dumped in pits called waste lagoons - send disease causing microbes and toxic chemicals into surface water and air ■ 4100 extending over 6800 acres in low lying spots near bodies of water ● 37 within ½ mile of a school ● 288 within ½ mile of a church ● 136 within ½ mile of public water well ● 170 within state’s 100 year floodplain ○ New maps let people see social and environmental impacts of animal farms ■ Use aerial photography ○ General public cant see salient facts about state’s poultry operations ● Watch the last segment of this episode of Democracy Now ○ House bill 467: limits damages residents can collect against hog farms ○ Spray the hog waste into the air ○ Drones are used to capture footage of the hogs and farms ○ Hog waste falls on floors, flushed to open pit, pit fills up, emptied by spraying liquid waste, drifts into neighboring communities, leads to strong odors and adverse health effects

○ Odors encompass all neighboring communities ○ Spray consists of animal waste of hogs in the tent metal housing, aborted baby piglets, chemicals, methane and ammonia gases produced from the waste and urine ○ Hog communities concentrated in low socioeconomic areas in southeastern north carolina ○ Lawmakers believe it’s necessary t...