GEOG 205 2019 Midterm Review
3 parts of hydroelectric plant
- power plant where the electricity is produced - a dam that can be opened or closed to control water flow - reservoir (or lake) where water is stored
Eutrophication defined again
-Accelerated Eutophication: "Cultural Eutrophication" -Excessive growth in algae leads to algae blooms known as "red tides"
How would heavy grazing impact the land?
-Excessive trampling will break up plant litter and can be removed by wind. -Trampling can accelerate soil deterioration and water erosion. -Grass biomass (fire, fuel) reduces: grassland fires reduces (which would have killed or suppressed woody plants) -With not as much grass competition, unpalatable woody species increase coverage -Result of heavy grazing: transition from grassland to shrubland
Top-Down Cascade
-In which the top predator controls the population of secondary consumers (e.g. wolves hunting deer) -When the predator is removed from the environment, secondary consumers begin to have pop. growth (ex: increase in deer pop.) -With this population growth comes a dramatic decrease in primary producers(plant life) -In this way, removing the wolves damages the growth of primary producers
aquatic biomes
-freshwater regions: ponds, lakes, streams, rivers, wetlands -marine regions: oceans, coral reefs, estuaries
2 main purposes of groundwater use:
-municipal consumption (51%) >public supply, domestic supply, rural (99%) -agriculture >irrigation(64%), livestock, aquaculture -other uses: >industrial, mining, thermoelectric
Mineralization
-part of phosphorous cycle -Within the soil, organic phosphate can be broken down into phosphorous
when were wolves reintroduced to yellowstone
1995
When did the period we are in begin?
2.6 million years ago
what is the one natural lake in TX
Caddo Lake
What are feedback loops?
Involved coupled systems that collectively act to accelerate or decelerate & initial change -> can be positive or negative
What animals gathered once more trees grew?
More birds and beavers began to move in
Overfishing
The process in which fish are being taken out of the environment at a rate faster than they can be replaced. This can hurt habitats as well.
runoff
This is the process in which water moves over the earth's surface. This can be seen as snow melts into water and moves down earth's topography.
According to the Global Carbon Cycle slide, what holds the most carbon?
sedimentary rocks
terrestrial biomes
similar terrestrial biomes within shared latitudes -tropical rainforests, savannas, subtropical deserts, chaparral, temperate, grasslands, temperate forests, boreal forests, arctic tundra
Species Diversity
species diversity is a measurement of biological diversity to be found in a specific ecological community. it represents the species richness or number of species found in an ecological community, the abundance (or number of individuals per species), and the distribution or evenness of a species. This can be used to evaluate biodiversity.
endemic species
species that are native to and found only within one area (regardless of size)
El Nino is an example of...
teleconnections
What 2 factors influence terrestrial biomes?
temperature (latitude) and precipitation
Acid rain sources and effects on terrestrial systems
terrestrial systems -trees and plants less healthy by robbing soil nutrients -adds stress to forest growth by impacting reproduction ability
Biomagnification
the concentration of toxins in an organism as a result of its ingesting other plants or animals which the toxins are more widely dispersed. Example: Plastic is put into ocean Phytoplankton absorb PCBs Phytoplankton are eaten Eventually, humans eat fish that ate phytoplankton so we consume PCBs
What latitudes have the greatest amount of biodiversity?
the tropical latitudes
major uses for surface water
- public Use, hydroelectric plants, agriculture and irrigation -Public Use Providing clean drinking water to its citizenry is one of the hallmarks of a well-governed populace In 2015, nearly 40000 million gallons of water were pulled for public use daily. The vast majority coming from surface water sources. As environmental conditions change, due to natural and anthropogenic causes, so to does stress on the system. -Will this be a worry moving forward? Almost assuredly, as global populations grow, so too will public demand of drinking water. Hydroelectric Plants 16% of the world's and 7% of the US energy comes from hydroelectric -Agriculture and Irrigation Irrigation is the process of applying water to crops to sustain and grow the nation's food sources Irrigation and other agricultural pursuits accounts for roughly 80% of the nation's consumptive water Surface water systems are regulated to prevent over taking (more on this later) Irrigation uses vary drastically by location
Why are nutrient cycles important?
-All matter is conserved and recycled -Transform elements from one of matter to another -Transfer elements from one place to another -Can store elements -Assist with the proper functions of ecosystems -Link elements with living organisms -can help regulate the flow of different substances within each "sphere" -These cycles help transform nutrients from biotic systems to abiotic systems -Biotic(living systems): biosphere, carbon, hydrogen, nitrogen, oxygen, phosphorous, sulfur -Abiotic(nonliving systems): atmosphere, hydrosphere, lithosphere, cryosphere
Results of Agricultural Revolution
-By taking up agricultural practices and animal domestication, humans were able to significantly reduce the space needed for sustaining each individual by about a factor of 500 at least -This allowed for population densities to increase, leading to the establishment of towns and later cities. -Through controlled breeding of plants and animals, humans were able to foster much more reliable sources of food. This allowed for more leisure time and the development of cultural advancements.
Overhunting, overfishing, invasive species
-Humans have become a major driver of trophic cascades -Much of human activity is having major impacts on the flora and fauna of the ecosystems as we: >Hunting predator species greatly reducing, or even eliminating their populations(wolves, sharks, big cats) >overfishing of ocean resources(tuna and other game fish) >transplanting species into areas in which they are not native and become invasive
What is a Global Boundary Stratotype Section and Point (GSSP)
-Internationally recognized system to define each stage of geologic time: began in 1977 -Determined by International Commission on Stratigraphy -> Anthropocene Working Group: Section of International Union of Geological Sciences
How would light grazing impact the land?
-May increase productivity of wild pastures >removal of coarse, dead stems permits succulent sprouts to shoot >seeds are dispersed after being eaten and then trampled into soil surface >feces of grazing animals modifies and enriches nitrogen in soil
Events that are potential measures for the start date of the Anthropocene are...
-Megafauna Extinction 50,000-10,000 yr BP Near global -Origin of farming ~11,000 yr BP Southwest Asia, becoming global -Extensive farming ~8,000 yr BP to present Eurasian event, global impact -Rice Production 6500 yr BP to present Southeast Asian event, global impact -Anthropogenic Soils ~3000 - 500 yr BP Local event, local impact, but widespread -New- Old World Collision 1492-1800 Eurasian-Americas event, global impact -Industrial Revolution 1760 to present Northwest Europe event, local impact, becoming global -Nuclear Weapon Detonation 1945 to present Local events, global impact -Persistent industrial chemicals ~1950 to present Local events, global impact Source: Lewis & Maslin 2015
Humans overhunting sea otters began what chain of events?
-Negative Trophic Cascade: ex. sea otter >Humans hunted sea otters from pacific coast states for their pelt >The pacific purple sea urchin was the main prey of sea otters, which began to overpopulate >Pacific Purple sea urchin primarily consume Giant Kelp >Giant Kelp populations plummeted from over predation >Giant Kelp are important in preventing beach erosion. Due to removal of sea otters, beach sand was negatively impacted
Subsidy Cascade
-Occurs when one trophic level supplements or replaces its food from a non-native source -This can be seen with herbivores consuming farming crops or coyotes eating sheep
what main nutrients are over-abundant when disposed as runoff?
-Overabundance of nutrients: nitrates, nitrites, phosphate, etc. -wastewater treatment discharge -sewage discharge -agricultural runoff (fertilizers, animal waste, etc.) -Synthetic and organic point source pollution
What are GSSPs defined by?
-Primary markers (e.g. dating of fossil species) -Secondary Markers (e.g. chemical markers) -Well preserved geologic sections and key events
Bottom-Up Cascade
-Primary producers control higher level predators' population -If there is an abundance of plant/algae, it will benefit secondary consumers -Growth in secondary consumers provides predators more fuel/hunting opportunities so their populations grow -In this way, a drop in plant life (through development, or other means) will eventually impact apex predators
Human impacts on various biomes
-Rainforests: deforestation, biodiversity loss -Oceans: Plastic pollution, over fishing -Rangelands: overgrazing, habitat loss -Savannahs: land-use/land cover change -Wetlands: destroyed for commercial development -Deltas: Over-loaded with nutrients and pollutants from fertilizers
Why does the urban heat island effect occur?
-Reflecting radiation is retained by high walls and dark-colored roofs -Concrete surface: heat is stored during the day and release at night -Artificial heat produced by industrial, commercial, and domestic users -Vegetation in rural areas enhances evapotranspiration - relatively
Clean Air Act of 1990
-Targeted acid rain >put limits on emissions >reduction of 88% of sulfur dioxide emissions between 1990 and 2017 >air quality standards drove 50% reduction in nitrogen oxides >result = emissions fell, rainfall & surface waters less acidic >recovery is NOT immediate -> Stream macro-invertebrates (within 3 yrs) -> Lake zooplankton (a decade or more) -> fish populations in lakes and streams (5-10 yrs after recovery of macro-invertebrates) ->Trees (decades-- b/c long life span and soil recovery)
Levels of trophic systems
-Tertiary: is composed of apex predators that prey on and eat the carnivores and herbivores; in the 4th level -Secondary: is composed of carnivores and omnivores that consume and prey upon herbivore creatures -primary: are herbivores that eat only plants and algae as their sources of energy. herbivores cannot manufacture their own food -primary producers: plants and algae comprise this level of the trophic system. Called primary producers or autotrophs, plants and other other organisms create their own food using photosynthesis.
human activities that impact the water cycle
-agriculture, industrial pursuits, urban sprawl: have affected every stage of the water cycle >Human regulation of stream flows and runoff manipulation have caused 41,022 km^3/yr to be diverted, reducing ocean and surface water sources from rising >urbanization can have drastic implication on the water cycle. Impervious surfaces can decrease groundwater levels, change and/or increase flood risks and increase pollution risks >Human activities have caused an increase in water pollution and accessible potable water >As nature is replaced with the built environment, changes in evaporation have increased heat in urban centers.
major drivers of biodiversity
-climatic stability, habitat heterogeneity, primary production -characteristics of the tropics that drive biodiversity: >climatic stability: not as much variation or wide swings in temp. btw. seasons >Primary production: more food choices allows for more dietary specialization which leads to a smaller niche
Eutrophication
-excessive richness of nutrients in a lake or other body of water, frequently due to runoff from the land, which causes a dense growth of plant life and death of animal life from lack of oxygen.
human activities that impact surface water
-modification of rivers >diversions >channelization -inter-basin transfers -dams -impact of urbanization >rivers >lakes >wastewater reuse >point and non-point source pollution -irrigation -water pollution >salinization >eutrophication >pervasive plastics >emerging contaminants ->pharmaceuticals ->pesticides ->industrial chemicals ->personal care products
human activities that impact marine ecosystems
-tourism: cruises, recreational fishing, diving, etc. -recreation -commercial fishing -coastal communities -freshwater runoff: sediment transport, nutrient transport, chemical pollutants
Perturbations
A change in earth's energy balance or climate systems
Define Anthropocene
According to Steffen, it means "a new epoch when human activities have become so profound and pervasive that they rival, or exceed the great forces of nature in influencing the functioning of Earth systems." -"Anthro": human -"Cene": epoch -Proposed epoch indicating significant human impact on natural systems -New "age of man", where humans have begun to significantly alter dynamic processes of the environment like the biosphere, hydrosphere, atmosphere, lithosphere
Define albedo and what has a high vs low albedo
Albedo: (means "whiteness") measures reflectivity of a surface -High Albedo: reflects a high proportion of light -Low Albedo: absorbs a high proportion of light -Albedo = proportion of energy from the sun reflected >Concrete = low albedo (gets hot and absorbs energy) >Snow = high albedo (reflects the radiation >Locations: --> Deserts have high albedo -->Tall rainforests have low albedo
What was the Agricultural Revolution?
An event that occurred ~11k - 3k BP where animal domestication and crop domestication began. -Animal Domestication: domestication of animals allowed humans to stay in place for longer periods of time rather than following animal migration patterns -Crop Domestication: The cultivation of crops also helped humans in establishing permanent homes
Forcing
An imposed perturbation. A positive forcing warms the earth, such as a solar flare, a negative forcing can cool the earth, such as an increase in particles in the atmosphere from a meteor impact that reduces the energy that reaches earth.
Teleconnections
An understanding of climactic relationships that span great distances (across non-contiguous regions) that can provide predictability of climate systems during various time frames. El Nino is a good example.
precipitation
As atmospheric conditions change, the clouds will release their water in the form of rain. Altitude, temperature, and location all affect this process.
condensation
As the vapors cool in the atmosphere, they change into ice particles. These particles combine to form clouds and fog.
Why was fire suppressed in the early 1900s?
Back in the late 1800s and early 1900s, much of America's forests were logged. These were heavy logging operations that deforested vast areas of the Midwest, the Appalachian Mountains, the South, and the Pacific Northwest. Much forest land had already been cleared for agriculture, of course, but this logging episode cleared much of the rest. Great piles of logging slash were left to dry on the ground as the loggers moved on to cut other forests. This dried material fed devastating fires that killed young trees. There was much concern over the ability of our forests to recover. This concern gave the US Forest Service and state forestry agencies the impetus to try to halt all fires. As we now see, it was a mistake to try to remove fires from every forest. Part of the problem was that academic forestry was based in the northeastern US, where many of the forests are not flammable and don't need fire. Foresters there applied their understanding to the rest of the country, where it really didn't fit.
How did vegetation react to the deer?
Because deer began to avoid certain locations, immediately certain plants began to grow more.
Via what human action is large amounts of carbon released into the atmosphere?
Carbon moves from living things into the atmosphere. Creatures exhale CO2 into atmosphere. Carbon moves from fossil fuels to the atmosphere when fuels are burned. Mainly through industry and energy production. This is a major human contribution.
What era are we currently in?
Cenozoic Era
proxy data
Data gathered from natural recorders of climate variability such as tree rings, ice cores, and ocean-floor sediments. -Tree Rings are a great example of proxy data. Data is gathered by getting cross-section of tree or tree core. Peat cores are also a good example of proxy data. Deep Sea corals are also a good example as they are gathered by getting cross-section of coral disk.
Where do primary producers get their energy?
Energy -> Producers -> -photosynthesis -cellular respiration -chemosynthesis >thermal vents and chemosynthetic bacteria
sublimation
Is the process of ice converting directly into vapor w/o turning into a liquid. This process is most common at the ice sheet of North and South Poles.
Where is the saturated zone?
It is determined by where the water table is located
Klamath Water Wars Podcast: What major stakeholder viewpoints were identified?
Klamath Tribes, Government, Local Farmers -focused on issue of dam removal in a particular area -Klamath tribes and local farmers found point of compromise, but congress didn't pass compromise
What happened without the wolves?
Number of rabbits and other animals was down as coyote numbers were up and deer population was high
What is the scientific method?
Observation, Hypothesis, Experimentation, Data Analysis, Conclusion, Report
direct measurement
Occurs when the behavior that is measured is the same as the behavior that is the focus of the investigation -Measuring River Flow: data is gathered by topographic mapping with total station, acoustic Doppler velocimeters, modeling -Measuring Climate Change: download datasets from public databases, use paleoclimatology
how does plastic get into the ocean?
Plastic debris is put into ocean by humans. Plastic then spreads. Even on remote islands, large quantities still present.
What 3 epochs are in this period?
Pleistocene Epoch, Holocene Epoch, Anthropocene Epoch
in what ways can overfishing impact the marine environment?
Probably leads to some sort of trophic cascade as it effects food chain.
What period are we in?
Quaternary Period
biodiversity hotspots
Relatively small areas of land that contain an exceptional number of endemic species
How did the rivers react to the reintroduction of the wolves?
Rivers began to erode less because the regenerating forests stabilized the banks, which made it erode less.
What does science show?
Science shows evidence for things, but science does not prove things
transpiration
Similar to evaporation, liquid water is turned into water vapor by plant life. The plants move water from the soil through their roots upwards to the leaves where water leaves through the stomata.
infiltration
Some of the water, through precipitation and runoff, moves into the soil. This can seep deep into the earth and increases ground water tables.
what do some plastics contain that can lead to reproductive disorder and death in marine species?
Some plastics contain polychlorinated biphenyls (PCBs), which contain lead -> reproductive disorder and death
Clean Water Act of 1972
Still in place today with amendments Mainly regulates point source pollution (e.g. industry, treated wastewater) Illegal to dump point source pollution into navigable waters without permit National Pollution Discharge Elimination System
surface water is the property of: state or private?
TX owns all the surface water, including every river, natural stream, lake, bay, and the arm of the Gulf of Mexico
Is the Anthropocene a former epoch?
The Anthropocene is not a former epoch. It is an epoch that we are arguing over whether we are in now. The start date is the main argument point. There are a few that argue that it hasn't quite begun just yet.
Quantitative data
The data collected can be expressed and measured with numbers/statistically. Ex: surveys, statistical analysis, etc.
How did the deer react once wolves started hunting them again?
The deer began to avoid certain locations
what do researchers measure to measure fire frequency in trees?
Today, resource managers are using prescribed fire to try to reverse the negative consequences of too much fire suppression. It's difficult, though, to know just how much fire should be used, and where. That's because we're separated from the historical burning by a century, and we just don't know how fires behaved and how often they occurred in the past. This means there is quite a bit of debate about the proper role of prescribed fire. Some researchers, including in the Geography Department here at Texas A&M, are working to fill this gap in knowledge by conducting research on fire history. This photo shows one example of how we learn about fire history. The pine tree has a wound that was caused by past fires, and the student is using a chainsaw to cut a section of the tree that contains the old fire scars. This section is taken back to the lab and analyzed, as shown in the next slide. But one thing to notice here is how thick the shrubs are in this forest. This is another example of a once more-open forest that has become dense without fire. There is virtually no pine or oak reproduction here. The seedlings simply can't tolerate all the shade. Here's a look at a slice of wood cut from a fire-scarred trees. The arrows point out scars caused by eight different fires in the 1800s and early 1900s. By dating the tree rings, we know the years when the fires burned. Notice that each fire scar is separated by only a few tree rings, meaning that the fires burned every few years until 1921. Then the fires ceased and the vegetation started becoming more dense. This kind of data gives many insights about fire, and is used by resource managers to guide their prescribed burning. Many uncertainties still remain, such as how large the fires grew in the past, and how many were set by people versus lightning. But at least we are gaining some clarity about the role of fire in the past, and how it can be used to restore fire-dependent vegetation, if only in relatively small areas of the landscape.
What are the 3 types of trophic cascades?
Top-Down Cascade, Bottom-Up Cascade, Subsidy Cascade
What type of trophic cascade is the reintroduction of wolves?
Top-down cascade
When can theory become fact?
Trick Question: Never -Scientific findings most often expressed with numbers and statistics, but statistics can be manipulated, and scientific findings never prove things
In the SE US, what happens w/o fire?
W/o fire some things are put into a position that is less advantageous ecologically and economically. -Here's what happens without fire in the Southeast. Other tree species and shrubs encroach, and the understory plants are choked out by all the shade. The pines cannot reproduce either because the seedlings require a lot of light. The vegetation gradually shifts to another condition.
define groundwater
Water (not groundwater) held by molecular attraction surrounds surface of rock particles. Then there is the water table. All opening below the water table are full of groundwater. -Water held underground in the soil or in pores and crevices in rock.
What was the climate like when humans first colonized the earth?
When we first colonized the Earth the climate was experiencing the Ice Age.
Where does the wolf video take place?
Yellowstone National Park
Biome
a biome is a geographic area that is defined by a specific environmental factor
genetic diversity
a measure of the genetic variation among individuals in a population. this can be used to evaluate biodiversity
Earth Systems Science
applies a "systems-science" approach to natural systems. It considers complex interconnection feedback loops, forcing, perturbations, and teleconnection
Major Earth Systems
biosphere, hydrosphere, lithosphere, atmosphere, cryosphere
mass extinction
catastrophic loss of the world's species from rapid change or event (rapid climate change, sustained volcanic activity, etc.)
Water Rights Adjudication Act in TX
combined riparian and appropriation laws in 1967
global extinction
complete loss of a species/gene pool around the world
What are examples of human land use land cover change?
development of lands for agriculture or for development of cities?
steps of the hydrological cycle
evaporation, condensation, sublimation, precipitation, transpiration, runoff, infiltration
Which part of the water cycle helps plants reduce surface temperature?
evapotranspiration?
what percent of surface water makes up freshwater
freshwater overall is 2.5% and surface water makes up 1.2% of freshwater
Surface water vs. groundwater
groundwater is located underground in large aquifers and must be pumped out of the ground. surface water is found in lakes, rivers, and streams. It is drawn into public water supply by an intake.
What do red tides cause?
leads to "dead zones" - toxic for aquatic life and humans that consume tainted aquatic life
red tides
massive algae blooms
What is the official start date of the Anthropocene?
most "official" date is 1950 (according to the AWG)
what is a common reason for man-made lakes in the US
most lakes in the US were created by human engineers, in part to produce electricity
what are the 2 main categories of fire ignition
natural and anthropogenic
% of surface water used in US
not sure if this is what is asking, but the module says that 70% of all water used in the US is from surface water
What are biogeochemical cycles also known as?
nutrient cycles
Acid rain sources and effects on aquatic systems
nutrient pollution depletes oxygen -eutrophication -decline of various species of fish
what makes up 96.5% of the earth's water
oceans
causation vs correlation
oftentimes one variable can cause another variable to change or occurs. Sometimes there is no actual link -media and politicians can distort or oversimplify statistics easily
nitrification definition
part of ntirogen cycle -the process by which ammonia gets converted into nitrite into nitrate
point source pollution
pollution that comes from a specific site -Leaking Septic Systems Storage Tanks ~10 million in the US Corrode over time Uncontrolled hazardous waste ~20000 abandoned/uncontrolled hazardous waste site Leaking landfills
Groundwater is the property of: state or private
private in tx
Qualitative data
the data collected is based upon the properties and descriptive values of the item being studied. Ex: observations, interviews, surveys, pictures, recordings, etc. (subjective)
biosphere
the layer of life and all ecosystems on Earth (It is a very complex set of interconnected systems)
local extinction
the loss of a species in a local place, but other members of the species exist somewhere else
Define land cover change
the loss of natural areas, particularly loss of forests to urban or exurban development, or the loss of agricultural areas to development
spatial scale
the physical size, length, distance, or area of an object or the physical space occupied by a process
Evaporation
the process in which the surface water is heated from the energy of the sun and turns into vapor. This moves the water from the hydrosphere into the atmosphere.
hydrological cycle (water cycle)
the sequence of events in which water continuously moves from surface water, into the atmosphere through evaporation, falls back onto earth, moves back and forth btw. surface & groundwater sources, ultimately back into the atmosphere and the cycle continues
How can a water table fall?
the water table can fall as a result of heavy pumping exceeding the recharge
temporal scale
time units at which an ecological phenomenon or condition occurs
True or False: the amount of carbon in the atmosphere has a positive relationship with atmospheric temperature
true
T or F: all surface water has the chance to percolate down to aquifers
true?
ecosystem diversity
variety of habitats, living communities, and ecological processes within an ecosystem. This can be used to evaluate biodiversity
non-point source pollution
water pollution that does not have a specific point of origin -Agricultural Runoff Feedlots/animal waste Nutrients from fertilizer Pesticides -Urban Runoff Chemicals (fertilizer, pesticides, etc.) Treated Wastewater Storm water/sewage overflow Road salt, etc. -Atmospheric Contamination Acid Rain Precipitation
urban heat island effect
when an urban area has higher temperatures than surrounding areas
Where is most groundwater found?
zone of saturation (in aquifers)