Ecology Final

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-Nutrient forms and transformations

Based on major reservoirs in the biosphere Gaseous: atmospheric pool, e.g. nitrogen cycle. Sedimentary: Lithosphere (rock) pool. e.g. carbon and phosphorus cycle Hydrologic: oceanic pool, e.g. water cycle.

-Fixation

nitrogen from the atmosphere is added to the soil nitrogen pool; thus, fixation is an input Nitrogen exists as dinitrogen gas (N2) in the atmosphere. The two nitrogen atoms that make up each N2 molecule are held together by a very strong triple bond, making the nitrogen in the air inert (chemically non-reactive). Microorganisms fix atmospheric nitrogen and convert it into forms that plants can readily utilize. A few bacteria and cyanobacteria (also known as blue-green algae) convert atmospheric N2 into inorganic forms of nitrogen that plants can use. Split N2 bond Turn into ammonia NH3 Turn in to plant usable NH4+ Ammonium

Milankovitch cycle

o Eccentricity - Oval orbit around the sun (100,00 year cycle) o Obliquity - Shift in tilt of the earths Axis (41,000 year cycle)

Why is the Earth warming?

o Greenhouse gases have been the primary driver of modern climate change. o Earth's climate would be even warmer were it not for the aerosols that are released during fossil fuel and biomass burning. o Natural forcings had a marginal impact on global mean surface temperature (GMST).

Warm ocean temperatures off the coast of South America in El Nino years are a result of?

reduced upwelling

-Upwelling

up welling of nutrients of the coast of South America

Las Vegas water shortage

• Current water source 90% Colorado river. • Alternative water source 285 mile pipeline, transport water from aquifer in eastern Nevado. • Sustainable solution? - NO, aquifers normally do not refill

-Position High - Low pressure systems

• Difference in atmosphere pressure between Tahiti and Darwin, Australia. • In normal and La Nina years, high pressure is over Tahiti and low pressure over Darwin. • This contributes to a westerly flow of equatorial wind and ocean currents.

-Ocean temperatures

• El Nino associated with warmer ocean temperature in eastern Pacific (e.g., Peru). but cooler temperature in western Pacific (e.g., Darwin).

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Week XII

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Nitrogen Pollution

- Human are nitrogen fixers -The production of synthetic nitrogen fertilizer adds nitrate or ammonium directly to the soil, bypassing part of the natural nitrogen cycle. The denitrification systems in many ecosystems are not able to keep up with the high rates of artificial nitrogen fixation occurring with fertilizer Industrial nitrogen fixation greatly increases crop yields, but also produces large amounts of nitrous oxide, a greenhouse gas, and nitric oxide, an important contributor to smog and acid rain.

-Effects on forests

- Soils with a naturally high pH can buffer the initial impact of acid rain. Generally, the more alkaline the soil, the less impact acid rain will have. However, any significant change in soil pH will affect plants growing in that soil. Because plant species have different pH tolerances, shifts in soil pH can alter competitive dynamics and thus the composition of local plant communities. ANSWER below Forests tend to be the terrestrial systems most sensitive to acid rain. First, acid precipitation physically affects forest vegetation by damaging leaves and needles, reducing trees' ability to photosynthesize, withstand cold, and reproduce. Although acid rain does not immediately kill trees directly, it reduces their vitality and ability to regenerate. Second, prolonged exposure to acid rain significantly impacts nutrient cycling in forest ecosystems. Over the long run, this indirect effect is especially harmful to trees.

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Week XIII

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Direct Consequences

---C02 Fertilization--- • Photosynthesis increases 40% when C02 increases to 500-600 ppm • Water vapor loss from plants decreases 22% • Water-use efficiency - C02 uptake/ water vapor loss from plants ---Photosynthesis vs respiration--- • Respiration by plants and soil microbes increases with warming in most ecosystems i.e., enzymatic effects. • Warming induced increase in respiration comparable to that of photosynthesis. • Annual C02 flux (balance) may remain constant. ---C02 effect magnified in drylands--- Increased dryland greening recently identified as missing carbon sink • 11% increase in plant mass since 1982 • Atmospheric C02 has increased 14% during this period • Important, but previously unrecognized, global carbon sink

Tragedy of the Commons

---Definition--- • Garrett Hardin American Ecologist 1968. • Used metaphor of multiple grazers in a pasture. • Assumed humans are rational selfish actors which would overgraze the land. • Commons pool resources are shared resources not owned by any user. •Resources degraded as a result

---Role of environmental institutions

---Department of Environmental Protection Agency (EPA) • Purpose to protect human health and environment by writing and enforcing regulations based on laws passed by congress - President Nixon 1970. ---Texas Commission for Environmental Quality (TCEQ) • Purpose to protect the States' public health and natural resources consistent with sustainable economic development. GOAL: Balance provision of private and public goods to maintain well-being of society. - Clear Act Act, Pres Johnson 63' - National Environmental Protection Act, Nixon 70' - Clean Water Act Nixon 72'

Climate Misconceptions

---Misconceptions.. • Humans cannot modify the Earth's climate • Warming occurs uniformly over the entire planet • Current warming is similar to Earth's geologic warming - cooling cycles ---Truth... • Humans cannot modify the Earth's climate o GHG composition in atmosphere - 1) Nitrogen: 78% Oxygen 20% Water Vapor 1% Inert gases (Mainly argon) 0.97% C02 and other gases 0.03% o Cumulative GHG emission since 1850 Carbon Dioxide 42% Methane (CH4) 150% Nitrous Oxide (N2O) 20% --((545 B Tons cumulatively ))--

Human Strategies for Climate Change

---Mitigation--- • Mitigation: modify management and production systems to reduce GHG emissions and sequester carbon from atmosphere into vegetation and soil. ---Adaptation--- • Adaptation: modify management, policies, and social systems to minimize negative impacts and exploit new opportunities. ---Geoengineering--- • Geoengineering: intervention into Earth's climate system to reduce global warming. o C02 sequestration- scrub emissions and store, produce biochar, ocean fertilization o Solar radiation management - sulfur clouds, cloud whitening, orbiting shades

Carbon cycle

---Pools---- • Oil and Natural Gas o Fossilized marine plankton o Cretaceous Period; 90-150 MYA • Coal o Fossilized terrestrial plants o Carboniferous Period; 280-360 MYA • 7 B tons emitted annually from fossil fuels. o 3 B tons remains in atmosphere o 2 B tons absorbed by oceans • Remaining 2 B tons by terrestrial systems, but where? ---Missing carbon sinks--- o 2003 - Northern boreal forest, especially Russia? o 2007 - Tropical rain forest larger than estimated? o 2015 - Arid regions during wet years? ----Fluxes---- fluxes during year the with seasons, due to photosynthesis and respiration. • Late summer to Autumn(Fall)= lowest CO2 concentrations • Later winter early Spring= highest C02 concetrations ---Fossil fuel combustion--- • Oil and Natural Gas o Fossilized marine plankton o Cretaceous Period; 90-150 MYA • Coal o Fossilized terrestrial plants o Carboniferous Period; 280-360 MYA

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Keeling Curve

-C02 concentrations - Just over 400ppm - early spring highest

Temperature is critical

-Mosquitoes like Aedes aegypti, the yellow fever mosquito, -They are important vectors for dengue, chikungunya, Zika, and other diseases of the tropical and subtropical world. -Cold winters have ensured that vectors like A. aegypti have rarely ventured north of South Carolina. Rarely, that is, until 2011, when a resident population was discovered in Washington, D.C. -Researchers think this shift in the mosquito's range may result from the combination of climate change and urban expansion that has increased the availability of warm winter habitats.

Carbon emissions

-Plant respiration -Fire -Land-use change -Soil respiration -Anthropogenic Carbon Output -Atmosphere Ocean change

two important classes of climate forcings:

1) Natural climate forcings typically include aerosols from volcanic eruptions, plus changes in solar irradiation resulting from variation in Earth's orbit or solar output. 2) Anthropogenic climate forcings result from human actions and include greenhouse gas and man-made aerosol emissions, changes in land use, and changes in ozone concentrations.

Solution to tragedy of commons

1.) --Private property rights-- - Assumed ownership will increase responsibility. - Degradation will directly impact the owner. 2.) Government regulation - Establish guidelines for proper resource use. - Monitor and enforce these guidelines. - Public land management operates this way.

-Soil leakage

Acidic water dissolves nutrients in the soil and washes them out via streamflow. Prolonged exposure to acid precipitation leaches aluminum from forest soil particles, and so acidic forest soils contain more solubilized aluminum than neutral soils. Aluminum in this form not only flows more readily into aquatic environments, affecting organisms there, but also inhibits trees' ability to take up nutrients. Trees are subjected to a double whammy: their supply of nutrients declines, and their ability to use remaining nutrients is impeded. Tree health gradually declines, resistance to drought, disease and pests decreases, defoliation occurs, and eventually death ensues. A forest's capacity to withstand these effects depends on how well its soil buffers acidification.

-Immobilization

After inorganic nitrogen entering an ecosystem from the atmosphere is fixed, it is then converted into organic compounds by plants and microorganisms. This process is known as immobilization. For example, ammonium compounds combine with organic acids to form amino acids and proteins A lot stored in soils as organic matter Lower availability leads to lower levels of nitrogen store in plat matter, reducing litter size

-Nitrification

Ammonium compounds can be taken up by some plants directly, but much of the ammonium produced during decomposition is converted first into nitrites (NO2-) and then into nitrates (NO3-), nitrogen species, which are much more soluble than ammonium and thus much more mobile. This chemical transformation is called nitrification

Tragedy of the Commons

Any commonly owned resource that may be publicly used is susceptible to the tragedy of overuse.

Which part of the year would you see the highest concentration of C02?

Autumn

Attribution vs detection

Can we detect changes in Earth's climate? - Earths climate is clearing changing "What is the use of having developed a science well enough to make predictions if, in the end, all we're willing to do is stand around and wait for them to become true?" — F. Sherwood Rowland Can we attribute detected changes to specific causes? -As this quote implies, attribution of climate change is contentious both because it is technically more difficult than detection, and because it has policy implications.

What does the fact that human consumption of NPP is often greater than 100% in urban areas suggest?

Cities are heterotrophic ecosystems. GPP/Re < 1 definition of heterotrophic

-Forest clear cutting

Clear cutting can reduce soil nitrogen levels and increase nitrogen lost via streamflow

Projecting future changes

Climatologists use GCMs not only for attribution studies but also to forecast how Earth's climate will change in the future. Despite the sophistication and accuracy of GCMs, their projections are inherently uncertain. This uncertainty results from the inherent variability of the climate system, from uncertainty about how Earth's climate will respond to changes in forcings and from uncertainty about future anthropogenic greenhouse gas emissions.

Open vs closed systems

Closed compartment model: that shows how nitrogen cycles between two pools, tree nitrogen and soil nitrogen, via two fluxes, nitrogen uptake and decomposition Open: Ecosystems receive and lose nutrients from and to a variety of external sources and sinks. One of the largest potential sources of nitrogen is the atmosphere. Through a process called nitrogen fixation

Plausible that human can alter climate

Concentration of GHGs Effectiveness in heat capture GHG's Captire 85% of re-emitted heat

-Cultural

Cultural services include nonmaterial spiritual, aesthetic, cultural, and recreational benefits people gain from ecosystems.

Lake ecology

Deoxygenation of the water in Lake Victoria at lower depths has followed the same pattern. Oxygen at lower depths has been decreasing to levels that cannot sustain healthy fish populations A secondary effect of the algal bloom in Lake Victoria is a big drop in visibility in the water. Vertical visibility was estimated at about 5 m in the 1930s and it has since reduced to less than 1 m in many areas of the lake. This change is thought to have negatively affected the breeding success of the brightly-colored cichlids, which cannot find each other in the murky water to mate

Aquatic vs. Terrestrial Ecosystems

Differ structurally but not functionally In Aquatic systems: - Primary producers are single celled organisms ( like phytoplankton) - Macrophytes rooted in shallow water Function is the same... - Energy flows among trophic levels -Nutrients cycles between biotic and abiotic portions of ecosystems

Ecosystem services

Ecosystem services are benefits humans receive from ecosystems including provisioning, regulating, supporting and cultural services.

Eutrophication

Eutrophication takes place when water bodies receive large inputs of nutrients, stimulating plant growth, particularly algae.

-Evaporation - condensation

Evaporation = liquid ----> vapor Condensation = liquid <---- vapor

Cont.

Everglades hydrology modified in mid-20th century. • Drainage canals supported agricultural development. • Kissimmee River channel modified 1960's; restoration began early 70's. • Lake Okeechobee diked in 1930's following to major hurricanes in 1920's. o Drying and burning resulted; peat soil burns o Sugarcane production rapidly increased • Flow rate reduced 1.5 to 2.0X since 1900. Eutrophication • Phosphorous input > 150 ppb in 1990's. • Inputs reduced to 30 ppb by environmental regulations. - loss of organic soils (peat) with drying Solution - Taxed fertilizer - impounded water from Lake Okeechobee

-Regulating

Regulating services include benefits derived from the regulation of ecosystem processes, including water purification, flood control, disease regulation, and crop pollination.

Climate forcing

Forcings, in the context of climate, are factors that can affect Earth's climate. They include both natural changes in things like solar radiation and volcanic emissions as well as changes that are anthropogenic in origin.

Temperature impacts across scales

From growth rate1 to sprint speed23 and nearly everything in between,4 the performance of ectotherms is closely tied to temperature. Even the sex of turtles and crocodiles is determined by the temperature of their nests.5 One big reason why individual performance and temperature are so closely linked is that a variety of cellular processes also vary with temperature. Temperature is absolutely critical to biochemical reactions, because it determines the effectiveness of enzymes controlling these reactions Enzymes control everything pretty much

general circulation model (GCM)

General circulation models (sometimes called Global Climate Models) or GCMs are three-dimensional models of Earth's climate. There are two general types. Atmospheric general circulation models provide a three-dimensional estimate of how various aspects of the atmosphere (e.g., temperature, humidity, and wind velocity) behave over time. Coupled atmosphere-ocean general circulation models link the three-dimensional behavior of the atmosphere with three-dimensional models of the ocean. Models of this second type are very complex, requiring intense computing power to solve, but have proven effective at capturing key features of Earth's climate system.

Carbon mystery

Global atmospheric CO2 is increasing at about 0.4% per year. Some of this increase is due to burning fossil fuels. If all the CO2 released from burning fossil fuels and land use change ended up in the atmosphere, atmospheric CO2 should increase by 0.7%, or 7.6 GT of carbon per Yet, only 3.2 GT of carbon per year is being added to the atmosphere, and the oceans are absorbing approximately 2.1 GT per year, which leaves 2.3 GT unaccounted for. A major unsolved puzzle in ecosystem ecology is to find the missing carbon. There is experimental evidence from biogeochemical studies and forest inventories that suggests northern latitude forests may be accumulating carbon at levels that can explain the missing sink in the carbon cycle

Impacts of Human Activities

Humans significantly impact how nutrients move around the planet. Our agricultural, forestry, and industrial pursuits all affect the cycling of carbon, nitrogen, phosphorus, sulfur, and water. For example, human activities have at least doubled the rate fixed nitrogen is being added to terrestrial ecosystems.1 Disturbing these biogeochemical cycles causes phenomena such as acid rain, the greenhouse effect, and eutrophication.

- effects on aquatic systems

If the pH of freshwater falls below 6.0, many aquatic invertebrates die and fish species decline. Once pH drops below 5.0, fish cannot survive, decomposers can no longer break down dead organic matter, and the ecosystem becomes severely denuded. As fish stocks dwindle and water quality declines, waterbirds, amphibians, and mammals also suffer.

Lake Victoria eutrophication

In Lake Victoria, nitrogen and phosphorus increased from 1960 to 1990 to more than three times their original concentrations Commensurate with the increase in nutrient levels has been an increase in algal biomass (as measured by chlorophyll a) and a decrease in water clarity as measured As a result, the amount of decomposing algae increased and the supply of oxygen in the water decreased, subsequently causing trout in the lake to go extinct.

Phosphorous cycling

In contrast to the nitrogen cycle, the phosphorus cycle does not include a substantial atmospheric component. Most phosphorus exists in sediments and mineral deposits. Weathering of rocks slowly releases phosphorus into terrestrial and aquatic ecosystems Thus most undisturbed terrestrial ecosystems are normally phosphorus-limited Humans also have a significant impact on the phosphorus cycle. Phosphate rock is mined for use in fertilizers, industrial processes, and the manufacture of detergents. Globally, the artificial transfer of phosphorus from rocks to soil is about five times faster than natural weathering.

-Lake Washington

In the 1940s and 1950s, the local human population grew rapidly and huge amounts of phosphorus-rich sewage effluent (20 million gallons per day at one stage!) were deposited into the lake. In the 1950s, local residents noticed that the lake water was becoming progressively cloudier and smellier, fish were dying, and phytoplankton were blooming every summer In the early 1960s, steps were taken to treat sewage more effectively and divert some of the effluent into tidally-flushed areas nearer the coast. The lake responded well to these changes and by the mid 1970s, annual algal blooms had ceased and the water quality of Lake Washington was greatly improved.

IPCC scenarios

Increasing Affluence (A1B) -Envisions a future with globally high economic growth, with energy demands met by a mix of energy sources, including some that release CO2 and some that don't. As the world becomes more affluent, population growth is expected to decline. Regionality (A2) -Envisions a future where global economic growth is both moderate and regional. Wide differences between countries' economies continue, and population growth is continuous throughout the century. Green Growth (B1) -Envisions a future where governments successfully reduce income and social inequities and increase environmental conservation, resulting in cleaner technologies. As with the Increasing Affluence scenario, population peaks mid-century and then declines.

- Natural vs anthropogenic

It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together. The best estimate of the human-induced contribution to warming is similar to the observed warming over this period

Uniformity of warming

Land vs oceans - Land will warm more than Oceans - Lower specific heat of land - Less energy required to increase temperature of land Low vs high latitudes - High latitudes are heated more than lower latitudes. - Oceans transport heat from lower latitudes

Attribution cont.

Like detection, attribution can be considered a signal-to-noise problem. In this case, the signal is the change in climate resulting from any particular climate forcing (such as elevated CO2) and the noise is the change in climate resulting from all other climate forcings and from the internal variability of the climate system.1

-Hubbard Brook Experiment

Likens and Bormann's study was designed to investigate how a forest and its vegetation affects the loss of nutrients from the ecosystem. When crops or trees are harvested, a large pool of nitrogen remains in the soil. With most of the vegetation no longer present to uptake this nitrogen, nitrite and nitrate leaching into groundwater, surface water, and outgoing stream flow increases. Lakes, estuaries, and ocean waters located downstream often receive increased nitrogen inputs via the watershed system. In extreme cases of nitrogen enrichment, water bodies can become eutrophic

-Orographic

Local heating of land warms water vapor to 35,00 feet in elevation, where it cools and precipitates

-Weather consequences

Marine ecosystems off west coast of South America e.g. fish and birds. o Food webs collapse due to reduced nutrients in water. Coral reef bleaching. o Warm water kills symbiont algae within corals. Crop and livestock production for human food supply. o Drought reduces crop and forage growth

Indirect Consequences Ocean acidification

Mechanism Coral reef bleaching • Absorption of 30% of anthropogenic C02 increases ocean acidity e.g., Carbonic acid. • Current increase about 30%; predicted to double in next 40 years. • Reduces production of calcium carbonate (CaC03) known as calcification. • Corals, crustaceans and molluscs most vulnerable to extinction. • 30% worlds reefs are now damaged and 50% may be lost in next 30 years.

-Mineralization

Mineralization (or "decay") is the opposite of immobilization. When dead organisms and animal waste decompose, the organic forms of nitrogen contained in that material are converted back into ammonia and ammonium. The rate at which nitrogen is made available to primary producers is determined largely by the rate of mineralization, at least in terrestrial ecosystems. Temperature, moisture, litter quality, and environmental chemistry determine the rate at which organic matter decomposes Litter quality reflects how easily dead matter is decomposed.

-Size and location of pools

More than 99% of Earth's carbon is tied up in rocks, particularly limestone, and cycles very slowly. So the major fluxes of carbon involve less than 1% of the total carbon on Earth, and of that, most involve carbon dioxide (CO2). Because oceans are so huge, the biggest pool of CO2 is actually in the deeper ocean waters, and, on the timescale of decades to millennia, oceans are the primary regulator of atmospheric CO2. When these organisms die, their bodies and shells drop to the ocean floor where they accumulate as carbon-rich deposits. Over long periods of time, these deposits form the sedimentary rocks like limestone where most of the Earth's carbon is stored.

Macro- vs Micronutrien

Nutrients required by all organisms in relatively large amounts are called macronutrients -carbon, nitrogen, phosphorus, sulfur, oxygen, and hydrogen Other essential nutrients are required in much smaller amounts. These are called micronutrients - zinc, iodine, potassium, and iron

Nutrient Cycling

Nutrients: elements required for growth and function of organisms Nutrient Cycling: movement, reuse, and transformation of nutrient in ecosystems. Nutrients availability influences many ecosystem processes. - Cycles between biotic an abiotic components - In contrast, energy flow is unidirectional rather than cyclic. -Both processes are closely linked in the biotic component of ecosystems.

Indirect Consequences Phenology

Periodic life cycle events that are correlated with seasonal variation • Spring begins 2 days earlier/decades past 3 decades e.g., leaf emergence, insect development, bird burst • Longer growing season in northern hemisphere (3 days/decades) • Life cycle 'mismatches' may result

Photosynthesis vs respiration

Plants take up atmospheric CO2 during photosynthesis, as they capture solar energy, and virtually all organisms release CO2 during respiration, as they consume stored energy.

-Mineralization

Plants use inorganic forms of nutrients: ammonium (NH4) or nitrate (NO3), but not gaseous nitrogen (N2) or organic N (protein). Animals ingest organic forms of nutrients: proteins in organic matter, rather than nitrate or ammonium as in the case of plants. Mineralization: nutrient conversion from organic to inorganic form during decomposition; inorganic nutrients then become available for reuse by plants Microorganisms like fungi, bacteria, and invertebrate animal species. Use dead organic matter as a source of energy and nutrients, e.g. deteriorates (Who brake down to size that bacteria can consume) .

Forest nitrogen pools and fluxes

Pool: if the magnitude of the input is greater than zero, the tree takes up nitrogen, causing the amount stored in the tree's nitrogen pool to increase. Simply stated: as the tree grows, it accumulates nitrogen Flux: Whenever a tree sheds leaves or drops branches, it exports nitrogen. Collectively, these outputs can be considered a single flux represented by an arrow pointing away from the tree.

-Provisioning

Provisioning services include ecosystem goods that are directly consumed by people, including food, fresh water, timber, and fiber.

Endangered Species Act

Purpose to provide protect critically imperiled species from extinction as a consequence of economic growth and development; President Nixon 1973.

Which of these scenarios do you think will lead to the greatest increase in atmospheric CO2?

Regionality

Residence or turnover times

Residence times in various pools • Atmosphere - 9 days • Rivers - 20 days • Oceans - 3,000 years

Sea ice vs glaciers

Sea ice increase in Antarctic Glacial melt in both Arctic (Greenland) and Antarctic

Cod Wars

So began the second of the three "Cod Wars" between Iceland and Britain, a heated set of conflicts over how to manage the cod fishery of the North Sea—a critical natural resource that had been used by both countries for centuries. Although the fishery began to collapse shortly after the arrival of European-based factory trawlers around 1960, fishermen were slow to blame overfishing for the decline. Instead, they argued that enviromental changes were causing fish growth rates to decline. In other words, they believed that cod stocks were diminishing because primary productivity had dropped and that the fishery could rebound on its own. However, in the 30 years that followed, scientists demonstrated that fishing pressure was responsible for the fishery's decline

-Eutrophication

Soil erosion and agricultural runoff caused by disturbances such as clearcutting and urban development lead to much of the phosphorus applied as fertilizer ending up in streams, rivers, lakes, and estuaries. Agricultural and human sewage, even after being treated, still contains high concentrations of phosphorus, which also flows into aquatic ecosystems Phosphorus enrichment of aquatic systems can lead to sudden blooms of phytoplankton and aquatic vegetation. Indeed, phosphorus has long been thought the main culprit responsible for the eutrophication of lakes, When lakes become eutrophied, water quality declines and dissolved oxygen is depleted

Hydrological cycle

Solar energy drives the water cycle. Evaporation = liquid ----> vapor Condensation = liquid <---- vapor Residence times in various pools • Atmosphere - 9 days • Rivers - 20 days • Oceans - 3,000 years water transports nutrient in ecosystems

-Supporting

Supporting services are the ecosystem processes necessary for the production of all other ecosystem services and include primary production, nutrient cycling, and soil formation

Ecological Footprint

The area of biologically productive land required to sustainably provide all the resources a population uses and to assimilate all of the waste it generates, given the prevailing technology. The figure to the right shows that between 1965 and 2007 humanity's Ecological Footprint grew from about 0.6 Earths to nearly 1.5 Earths. In other words, humanity's current annual demand is one-and-a-half-times that of Earth's annual productivity.

- bacterium Rhizobium

The bacteria form nodules on the roots of legume plants (see opposite) where they fix atmospheric nitrogen and convert it into ammonium. The bacteria share their ammonium with the plant in exchange for a supply of carbohydrate, which bacteria cannot synthesize. Mutualism Farmers often grow legumes with other crop plants to increase the amount of nitrogen available to plants in the soil.

Human fingerprint on climate change

The isotopic composition of atmospheric CO2 is quite different from that of fossil fuels. If greenhouse gases are causing the climate to warm, there should be a reduction in the amount of longwave radiation escaping to space in the wavelengths absorbed by CO2. If greenhouse gases are warming the planet, nights should warm faster than days due to diurnal changes in the atmosphere. Observations made during the past 50 years confirm this prediction and lend support to the hypothesis that changes in greenhouse gases are driving climate change Models predict that if increases in greenhouse gases are responsible for climate change, the stratosphere should cool as the troposphere warms. Observations confirm this prediction.1 Models also predict that if greenhouse gases are responsible for climate change, the height of the tropopause should increase. This, too, has been confirmed by observations . Because fossil fuels have a distinct isotopic signature, if fossil fuel combustion has been increasing the concentration of CO2 in the sea, this increase should have been accompanied by changes in the isotopic signature of coral. As predicted, the isotopic signature of fossil fuels began to be seen in corals across the globe beginning around 1850 and has been increasing ever since. If observed increases in CO2 (orange) are a result of fossil fuel combustion, they should be accompanied by a decline in O2. Confirmed!

Keeling curve

The keeling plot represents continuous data for atmospheric CO2, which show regular seasonal fluctuations, and mean CO2 levels per year, depicted as the smooth line superimposed on the seasonal variation. In terrestrial ecosystems, plants take up more CO2 in the growing seasons (spring and summer) and so atmospheric carbon is lower then than in winter. Most of the Earth's landmasses (and therefore terrestrial plants) are located in the northern hemisphere, which means global atmospheric CO2 levels are higher during the northern winter each year. The long-term increase in atmospheric CO2 is readily evident, despite seasonal fluctuations.

Goldilocks Principle

The population growth rate of ladybugs follows the "Goldilocks Principle", after the children's fairy tale Goldilocks and the Three Bears. It posits that performance is reduced when the temperature is either too high or too low, and is maximized when the temperature is just right.

Nitrogen cycling

The primary reservoir of nitrogen exists in the air where nitrogen makes up 79% by volume of the gases present (oxygen, which obligate aerobic organisms like us need for respiration, makes up only 21% or so of air). 5 steps fro nitrogen to move in or around or out ecosystems

Carbon and climate change

The reason the increase in atmospheric carbon receives so much attention is the potential for it to induce climate change. Increased emissions of carbon dioxide, methane, and other greenhouse gases are thought to be increasing annual mean temperatures around the world. Greenhouse gases trap radiation emitted from the Earth's surface, warming the atmosphere. With continued increase in atmospheric carbon, scientists predict that weather patterns will become more erratic and unpredictable, Northern Hemisphere winters will become warmer and wetter, and sea levels will rise around the world due to the melting of polar ice and thermal expansion of oceans. Global surface temperatures have been estimated to have increased by approximately 0.75 °C since 1900, and the increase appears to be accelerating: Global climate change has the potential to significantly alter species distributions, disrupt nutrient cycles, impact agricultural production, and affect human health.

-Frontal

The water vapor is blowing in the wind where it hits a mountain range. The air goes up where it cools, condenses, and precipitates on the other side of the mountain. This method creates rain shadows. This is the effect of the rain hitting on side of the mountain. Rain falls on the side its coming from, crosses over without moisture

Magnified greenhouse effect

Three greenhouse gases + water vapor Absorb long wave heat energy Radiative forcing Anthropogenic carbon sinks

-Services rely on NPP

To meet the demands of a burgeoning global Ecological Footprint, people have appropriated more and more of a critical supporting service, net primary production. In doing so, people have not only reduced the NPP available for other species but have altered ecosystems' ability to supply many other ecosystem services we rely on.

Carbon Cycling

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Ecosystem services

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Impacts of Disturbance

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Nutrient cycling

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-Convective

Two air masses of different densities meet. Cool dense air mass meets warm air. Warm air goes an top and cold air goes down Warm air cools and condenses, forming rain clouds.

Ecosystem services -Externalities

Unintended costs incurred by a third party (society) that is NOT involved in the market transaction; these costs are NOT reflected in the price of goods i.e. spillover effects. Fossil fuel energy use: Carbon pollution Extensive use of fertilizers: eutrophication Meat-based diets: inefficient used of energy, conversion loss of biodiversity & sequestration

Warming part of a natural cycle

Warming-cooling occurred in past Current warming much too rapid With the Eccentricity model the earth warms, but its a every 100,000 year cycle

Water cycling

Water is the primary transporter of nutrients (dissolved or suspended) within and between ecosystems. Evaporation is the engine of the water cycle Transpiration is the evaporation of water from plants into the atmosphere Throughfall is water that falls through the forest canopy. Infiltration is the gravitational movement of water into soil. Surface runoff is water from precipitation, snow melt or irrigation that does not infiltrate the soil, but flows over land surfaces into water bodies, often contributing to stream flow in the process.

Wet and dryfall

Wetfall and dryfall act as nutrient inputs in both terrestrial and aquatic ecosystems. Rainfall, snow, fog, and sleet contain dissolved nutrients absorbed by plants via soil water or directly through leaves. Nutrients are quickly distributed throughout a floodplain via flood water. Dust particles from fires, windstorms, and volcanoes are often rich in nutrients, and during periods of low precipitation, this airborne particulate matter is deposited as dryfall.

Acid rain

With a pH typically around 5.6, all rain is slightly acidic. The term "acid rain" refers to rain water that has been mixed with pollutants, decreasing its pH to 4.5 or lower. Acid precipitation is caused by the release of acid-forming gases, primarily sulfur dioxide (SO2) and nitrogen oxides (NOx) Burning fossil fuels, smelting ore, and other industrial processes release large amounts of SO2 into the atmosphere. . When these gases enter the atmosphere, they react with water vapor to form sulfuric and nitric acids and other secondary pollutants.

El Nino southern Oscillation is driven by differences in __________ in the eastern and western pacific:

atmospheric pressure

-Denitrification

denitrification is an important output that removes nitrogen from the soil pool and returns it to the atmosphere Plants uptake some of the nitrate produced during nitrification while the rest is converted in a stepwise process back into gaseous forms of nitrogen during the process of denitrification. Denitrification is the primary nitrogen transformation that removes nitrogen from an ecosystem and returns it to the atmosphere. Denitrifying bacteria are responsible for this chemical transformation. A series of chemical transformations occur during denitrication: 1. Nitrate (NO3-) is transformed back into nitrite (NO2-). 2. Nitrite is converted into nitric oxide (NO) and then into nitrous oxide (N2O), some of which escapes into the atmosphere. 3. Nitrous oxide is converted into atmospheric nitrogen (N2).

Common property governance

• Elinor Ostrom Noble Prize in Economics 2009. • Tragedy of the commons has been averted without privatization or government regulation. • Resource users can establish rules and norms to maintain sustainable resource use. -Human cooperation ---Maine lobster fishery--- • Fisher persons enforces regulations themselves. • Fishery organized into assigned territories. • Members only limits outsider; maintains rules. • Informal sanctions imposed on violators. (territorial, out of season) • Buyers enforce sanctions on ineligible lobster. (Size, females released)

-Interaction with jet streams

• High velocity air currents at transitions of major circulation (Hadley) cells. • Oscillation modifies precipitation patterns on a global scale by altering position of the jet streams and global circulation patterns. • El Nino events are telegraphed beyond the Pacific Ocean to 75% of Earth.

El Nino Southern Oscillation

• Large scale atmospheric and oceanic circulation system that influences ecological processes on a global scale

-Everglades case study

• Largest wetland in the U.S. • Outflow from Lake Okeechobee that is fed by Kissimmee River. • Sheet flow over 100-mile limestone basin into Florida Bay. • Approximately 50% of the area has been lost. • National park created in 1947 to protect 2,350 square miles of everglades.

Phosphorous cycle

• Maximum extraction projected for 2030. • P depletion in 50-100 years? • Mined from Earth's crust and guano deposits; major U.S. source is ocean going birds, nesting. • Non-substitutable nutrient that is essential to food security. • Recycling from plant and animal waste essential in future. •Mined out of open pits contributes to hypoxia: the depletion of oxygen in a biotic enviroment

Nitrogen cycle

• Nitrogen is an essential macronutrient for life on Earth. • Most complex cycle with multiple transformations of nutrient form. • Diverse species of microorganisms are involved in these transformations • Industrial formation of nitrogen currently exceeds biological formation. Haber process from N2 + H to NH3 N Fertilizer used to support 33% pf human population Contributes to positive global N balance

Hydrological Challenges

• Oceans hold 97 % of water on earth The other 2.5-3% of water (fresh water) is divided up as so.. • Ice caps / glaciers • Underground aquifers • Lakes and rivers • Soil water • Atmosphere (0.

Mechanisms of precipitation

• Originates from condensing of H2O vapor. • H2O condenses when it is cooled. • How is atmospheric H2O vapor cooled? next three cards...

-Land vs oceans

• Over land, precipitation 6% > evapotranspiration • Over oceans, precipitation 6% < evaporation. • Result is net transport of water from oceans to land. • Net water transport is balanced by runoff from land to oceans.

Eutrophication

• Over-enrichment of aquatic ecosystems with nutrients. • Contributes to excessive plant growth.

-Potential solutions

• Pipeline to transport water for Burleson County (Caldwell) to San Antonio. • 142-mile pipeline estimated to cost $3.4B and to be completed 2020. • Pipeline will provide 20% San Antonio water and reduce demand on Edwards Aquifer. • Pumping from Edwards Aquifer to protect endangered species by Endangered Species Act in 1991. Edwards aquifer is a larger limestone aquifer that has recharge zones

Ecosystem services -Primary goal

• Provide economic justification for ecological sustainability by placing value on non-market ecosystem services. • Optimize land use decisions by recognizing trade-offs among ecosystem services. • Minimize ecological externalities in transactions involving services valued in economic market. Private vs public goods

Ecosystem services -Four categories

• Provisioning - ecosystem goods consumed by society (e.g., food, water, fuel wood, genetic resources) • Regulating - influence processes beyond the ecosystem of origin (e.g., climate, disease, flood, and erosion regulation) • Cultural - social forces influencing human-nature relationships (e.g., spiritual/inspirational, recreational, aesthetic, educational) • Supporting - processes controlling the structure and function of ecosystems (e.g., soils, nutrient cycling, energy flow and primary production, biodiversity) Majority of ecosystem services have declined in the past 60 years

Acid rain

• S02 + water droplet > sulfuric acid • N0 + water droplet > nitric acid • Particulates fall with precipitation • First recognized in Scandinavia in 1950s; widely recognized in 1970's • Normal rain pH = 5.7; acid rain pH = 4.2 - 4.4

-Causes and processes

• Subsequent decomposition by bacteria depletes oxygen. • Respiration uses O2 and releases C02.

-Unequal distribution

• Wettest states in gulf coast region • Driest states in intermountain west - Nevada, Utah • Ecological implications o Biome distribution and productivity. • Social implications o Urban water supplies and food security. • Projected water deficits o Florida, southern plains (TX),

Ecosystem services -Private vs public goods

•Economic markets value goods, but not the ecosystem that supply them. •Provisioning services are private goods, while other categories of ESs are public goods - regulating, cultural and supporting •Provisioning services are internal to markets, while other ES categories are often external to markets. --------------------------------------- • Voluntary system where land owners are paid to supply specific ESs. • Payment offsets loss of provisioning services while increasing non-market services. • Procedure to translate non-market services into monetary assets. (Controversial) • Prevent non-market services from becoming externalized • Primarily focused on watersheds, C sequestration and biodiversity.


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