Environmental Science Test 3
How many years does it take to make an inch of top soil back? This is a rate of about ___ inches/year
500 years, a rate of about .002 inches/year
___ percent of Hawaii's original forest cover has been lost, ____ of its rainforest
66 percent; 50 percent
Island species make up ____ percent of extinctions
80 percent
Wetland losses approx. _____ acres annually
80,000
____ percent of the world's soil shows some degradation
85 percent
Background extinction is what percentage of all extinction
95 percent
What is simpson's biodiversity index?
A more quantitative measure of biodiversity
Whats a groundwater aquifer?
A rock or gravel formation that contains significant recoverable quantities of water that is likely to provide drinking water supplies
What percentage of deforestation happens in Brazil alone?
About 20%
What are the monetary impact of soil loss?
About 400 billion per year
How many inches of top soil do crops require to grow?
About 6 inches of topsoil, meaning it takes about 300 years to build up a reasonable amount to sustain crops and current average rates of erosion in the US are removing 6 inches of top soil in 150 years
What are the erosion rates of gully erosion?
Roughly 400 t/ha/yr, a rate that eliminates all topsoil in roughly 10 years
What was the endangered species act of 1973?
Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and development untempered by adequate concern and conservation."
What is slash and burn agriculture
Slash and burn agriculture is a widely used method of growing food in which wild or forested land is clear cut and any remaining vegetation burned. The resulting layer of ash provides the newly cleared land with a nutrient-rich layer to help fertilize crops.
Define soil; what is it influenced by? (4 things)
Soil is a loose, organic material. It is influenced by parent material, climate, organisms, and topography. Soil develops very slowly, over 100's of years
How is soil loss measured?
Soil loss is measured by calculating the amount of topsoil in tons that is lost each year per hectare due to water and wind erosion
2-3 t/ha/yr is what?
This is the tvalue for land where the top soil is very thin, 10 inches or less
What is topography
Topography is the shape or configuration of the land
What are the most diverse ecosystems on Earth?
Tropical forests
_____ rain forests are the most diverse in the world and have more than ____ the world's known living plants and animals
Tropical; 1/2
What is potable water
Water of sufficient quality to serve as drinking water
____ soils have low T values
Thin soils
what is the greatest threat to biodiversity?
fragmentation and degradation
Cattle Ranching. What percent of deforestation?
- 12 percent of deforestation - Frequently aided by government subsidies - 2 trees destroyed for each hamburger
What percent of water in our world is fresh water, and what percent is readily available fresh water?
- 2.5% - .003%
Commercial logging. What percent of deforestation?
- 21 percent of deforestation - creaming of the most valuable hardwoods - 1 - 2 trees per hectare taken - clear-cut vs. selective
Why is biodiversity so important? ____ percent of the _____ _____ is from biological resources
- 40% of the world's economy is from biological resources - greater opportunity for medical discoveries - boosts ecosystem productivity - each species has an important role to play - intrinsic value of nature
5 categories that water is used for and their percentage?
- 49 percent thermoelectric power - 31 percent irrigation - 11 percent public supply - 4 percent industrial - 1 percent aquaculture, mining, domestic and livestock.
What's the breakdown of fresh water?
- 87 percent ice and snow - 13 percent liquid water
What's the breakdown of liquid water?
- 95 percent groundwater - 3 percent lakes - 2 percent soil moisture
Name the four leaders of deforestation and how many million hectares have been destoryed
- Brazil, 11 million - Australia, 4.5 million - Indonesia, 4 million - Nigeria, 2 million
States that use the most water, 3.
- CA uses the most - TX is the second most - Nebraska, groundwater mainly, sits directly on top of an aquifer
What is forest fragmentation? Why does it happen, for what?
- Forest fragmentation occurs when large, continuous forests are divided into smaller blocks, either by roads, clearing for agriculture, urbanization, or other human development - forests are cut down in a manner that leaves relatively small, isolated patches of forest known as forest fragments
11 t/ha/yr is the t value for what?
- It's the t value for thick top soil, 60 inches or thicker. - in the US 11 t/ha/yr is considered the max allowable limit, any soil loss about that is considered excessive
What did the clean water act of ____ establish?
- The clean water act of 1972 established the basic structure for protecting surface water quality - the primary legislation concerning water pollution and its regulation - a variety of regulatory and non regulatory tools to sharply reduce and manage pollutant discharges in waterways and runoff
What is sequestering carbon? How does this relate to why swidden agriculture is bad?
- Trees have a natural ability to concentrate and store carbon. Through photosynthesis, trees absorb carbon dioxide (CO2) from the atmosphere and convert it to sugars. - Only when a tree or wood product decays or is burnt, does the carbon return to the atmosphere for further cycling in what is commonly referred to as the 'Carbon Cycle'. - Forests are an important sink for carbon in this cycle because they help to offset carbon dioxide emissions and other greenhouse gases that would otherwise contribute to climate change.
What is evapotranspiration
- Trees regulate temperature, and cool the air through a process called evapotranspiration. - Two processes: evaporation and transpiration, both release moisture into the air. - During evaporation, water is converted from liquid to vapor and evaporates from soil, lakes, rivers and even pavement. - During transpiration, water that was drawn up through the soil by the roots evaporates from the leaves.
Define environmental degradation
- any change or disturbance to the environment perceived to be deleterious or undesirable. - deterioration of the environment through depletion of resources such as air, water and soil; - the destruction of ecosystems and the extinction of wildlife.
What are hotspots?
- areas rich in biodiveristy - regions that have at least 1,500 species of vascular plants that are endemic, meaning found only there, and have lost at least 70% of original habitat
R Horizon
- bedrock - impenetrable layer
Point source pollution
- directly polluting, industrial dumping site - comes from a single location - pollution discharged through a pipe or some other discrete source from municipal water treatment plants, factories, confined animal feedlots, or combined sewers.
E horizon
- eluviation, leaching, layer - light in color - mostly sand and silt, having lost most of its minerals as clay and water drips through soil
Non point source pollution
- erosion, runoff - pollution discharged over a wide land area, not from one location - forms of diffuse pollution caused by sediment, nutrients, organic and toxic substances originating from land use activities, which are carried to lakes and streams by surface run off - generally from urban and agricultural areas
What is land degradation caused by?
- extreme weather conditions - human activities that pollute/degrade the quality of soils - agriculture - urbanization - deforestation
Whats a confined aquifer?
- held under pressure - water is under pressure between two confining layers of very low permeability called aquitards - since its under pressure water will actually rise up within the well and sometimes over flow
Where are most hotspots located? (3 places)
- in most tropical forests - islands - physically bounded areas by deserts or mountain ranges
A horizon
- layer called top soil - seeds germinate and plant roots grow here - made up of humus, aka organic material, mixed w/ mineral particles; living organisms - most important for agriculture
Why are forests important?
- living plants create oxygen for humans and species - transform carbon to oxygen; sequestering carbon - slow runoff and minimize soil erosion into streams and rivers - control atmospheric humidity through evapotranspiration - provide food and shelter - plants in tropical rain forests are used for modern medicine; the periwinkle plant in Madagascar treats lymphocytic leukemia
Utisoils. What percent are in the United States?
- low, moderately fertile soils - highly leached, acidic - thin, light - 12.8% in the United States
What does "n" stand for? What does "N" stand for?
- n is the number of organisms of a particular species - N is the total number of species present
Why is sediment a pollutant? How was it contaminated?
- number one pollutant by volume - contaminated years ago by chemicals such as DDT, PCB's and mercury - turbidity reduces photosynthesis - clogs up ecosystem
Mollisoils. What percent are in the US? Where are they found most often?
- old, soft, fertile soils - thick, dark surface horizon - 24.6 percent in US - grasslands, most important soil
What is selective logging?
- only a selected species or type of tree are cut down
Why have groundwater resources in the US been deteriorated?
- over pumping and/or contamination
Aquifers labeled from the top layer to the bottom later
- root zone - intermediate zone - water table - ground water - impermeable layer
Sediments find water by...
- sheet erosion - rill erosion - stream bank erosion and mass movement
What is Swidden agriculture? It accounts for ___ percent of deforestation.
- slash and burn; subsidence farming - accounts for 60 percent of deforestation - rapid decline in soil productivity - can be sustainable; 15 - 20 year rotation, fast growing crops for erosion soil, maize, rice, and other crops planted. - inequitable land ownership, only 5 percent of farmers actually own land
B horizon
- subsoil - contains clay and mineral deposits, iron aluminum, humic compounds, from A and E horizon
What is the effect of an o2 sag? Main idea: It's a ____ body of water
- the death of o2 breathing animals, such as fish, invertebrates and bacteria - can be a small, isolated area like a shallow point of a pond or can affect entire streams depending on severity of pollution - as o2 consuming animals die off, co2 consuming plants will soon follow as they run out of dissolved co2 - the result is a "dead" body of water
What is the oxygen sag?
- the dip in dissolved oxygen present in water that is the result of the introduction of waste material - if the waste is concentrated in a certain area, the oxygen will be depleted due to bacteria, which uses oxygen to survive, consuming the waste and releasing co2 as a bi product, causing an o2 sag.
What is the hydrological cycle?
- the pathways by which water constantly moves through the earth's atmosphere - evaporation, transpiration, and precipitation
What is the tvalue?
- the tvalue is the tolerable erosion value - it is the amount of soil that can be lost each year without requiring additional management inputs or substantially altering soil productivity, measured in tons per hectare per year
How do subsistence farmers relate to the deforestation problems?
- they rank high as important agents of deforestation - impoverished, landless people who will follow roads into already damaged rainforest areas and establish small scale farming operations
O Horizon
- top, organic layer - made up of fallen leaves and organic debris
What kind of water pollutants does the act regulate?
- toxins, biochemical o2 demand pollutants, total suspended solids, fecal coliform, oil, grease, and pollutants that alter pH
What are common characteristics of endangered and threatened species?
- usually a small area - specialized habitat or diet and can't adjust to alterations - low reproductive rate and low natural mortality - flightless birds/slow moving animals - overhunting of large animals - wild animals/plants that humans see as valuable for various reasons - island dwellers - species that breed in colonies and require large numbers of their own kind for protection, to locate food, and survival
What does it mean when it says that our planet is a very closed system?
- very little material escapes into outer space - the water that existed on earth millions of years ago is the same water that exists today
What's an unconfined aquifer?
- water table define the upper surface of the aquifer - recharged directly by infiltrating rainfall
Define destabilization of ecosystems
- weakening ability to deal with natural disasters and stresses - floods, droughts, hurricanes, pollution, and climate change
C Horizon
- weathered parent material - partially broken down inorganic minerals - slightly broken bedrock - plant roots don't penetrate - very little organic material
Nitrogen Cycle?
...
What does 0 and 1 represent in his index of biodiversity?
0 represents infinite diversity and 1 represents no diversity
12 million tons of topsoil if spread over a hectare would only be how many inches think
0.04 inches thick
Simpson's index of diversity formula is, what?
1 - D
Conservation 3 focuses
1. Agronomic measures, minimum tillage, strip cropping 2. Soil management techniques - focus on preserving or increasing the organic matter content of the soil 3. mechanical methods - increasing soil draining - applying chemical stabilizers to the soil surface - constructing soil retention structures
Where are the 3 US hotspots?
1. CA Floristic Provine 2. Caribbean 3. Small patches of Madrean-Pine Oak Woodlands in new mexico and arizona
Name the five leaders in percentage of forest lost between 2005 and 2010
1. Comoros, 40 percent 2. togo 24 percent 3. nigeria, 20 percent 4. Uganda, 13 percent 5. Pakistan, 11 percent
What are the four major ways biodiversity helps humans?
1. Plants absorb GHG's and help stop global warming 2. Easier for bio diverse ecosystems to recover from natural disasters 3. Healthy biodiversity of species can help provide a variety of food 4. Medicinal drugs
Name the three ways that background extinction is measured
1. The number of species that normally go extinct over a given period of time 2. Million species years - one extinction/per million species/per year 3. Giving species survival rates overtime - given normal extinction rates, species typically exist for 5 - 10 million years.
What is the 4 step process of soil development?
1. additions: ex. river adding sediments 2. losses, ex. erosion 3. translocation, ex. rainfall moving soil and depositing it elsewhere 4. transformation, chemical changes. ex. decomposition of organic material
What are the 3 key elements to help endangered species?
1. listing species as threatened or endangered 2. designating habitat essential for their survival and recovery 3. restoring healthy populations of the species so that they can be removed from the list
Name three ways that rain forests are system regulators
1. moderate air temperatures 2. maintain atmospheric humidity levels 3. regulate stream flows
top 5 reasons for soil degredation
1. overgrazing, 35 percent 2. deforestation, 30 percent 3. agricultural activities, 28 percent 4. overexploitation, 7 percent 5. industrialization, 1 percent
Overall 3 reasons why forests are important
1. sequestering carbon 2. habitat for animals 3. system regulators
Erosion removes soil from an area in a two part phase
1. the detachment of particles from the surface 2. the transport of particles by erosive agents, primarily wind or water
Between 2005 and 2010, Central America lost ____ percent of total forests each year, and Easter and South Africa lost ___ percent each year
1.2 percent; 0.7 percent
How many species have been identified? And ____ percent are _____
1.5 million are named alive, and 70 percent are invertebrates
How much arable land have we lost since 1950?
1/3; land the size of india and china combined has been severely degraded
What percent of species live in NA?
10 - 15%
What percent of contaminated sediment is underlying our nations surface water
10 percent of sediment underlying our nations surface water is significantly contaminated
Around the world, soil is being depleted on average between ___ - ____ times faster than it is being created, destroyed cropland that are cumulatively the size of ____ each year.
10 to 40 times; India
In some developing countries, soil is depleting at ____ t/ha/yr
100
In 2007, how many million tons per hectare per year were we losing?
12 million - about .04 inches of soil per year
How much does the average american, Japanese, french, and Germany person use each day? What about the world's poorest?
151 gallons, 99 gallons, 76 gallons, 34 gallons, and the world's poorest use only 2.5 gallons per day
In 1982, how many million tons per hecatre of soil were we losing per year?
18 million
Soil is being depleted each year ___ times faster than it is being built up in nature
18 times
Sewage treatment plants serve over ____ million people
180
In the _____'s, the rate decreased to ____, excluding the 19_ _ peak
1990's, the rate decreased to 1.5 million hectares, excluding the 1995 peak.
What is the t-value scale?
2 -11 tons/hectare/year or 1-5 tons/ac/yr - depends on the thickness of the soil
____ million hectares were lost in Brazil alone from 1978 to 1988
2.5 million
Today, nearly _/_ of the nation's water is deemed safe for swimming and fishing
2/3
Rates then increased in the ____'s, peaking at _._ in _____
2000's, peaking at 2.8 million hectares in 2004
In _____, the _____ had the most extreme drought on record
2006, the amazon had the most extreme drought on record. Thousands of fires broke out, which lead to a lot of dead forest.
On average in the US, soil is being depleted at a rate of ____ faster than it is being created
20x
How many species are estimated to still be unidentified?
3 - 50 million species
Deforestation accounts for ____ percent of all ____ ______
30 percent of all soil degradation
How many plant and animal species face extinction, estimated? How many birds face extinction?
34,000 plant species and 5200 animal species, and 1 in 8 birds.
____ hotspots are on ____ percent of Earth's land area
34; 2 percent
____ hotspots represent ____ percent of Earth's land surface
34; 2.3%
In the world, how much water is used each day? per person?
410 billion gallons used each day, one person uses 1,345 gallons
Individual species are estimated to live on average how many years before going extinct?
5 - 10 million years
Over a 20 year period, ____ million hectares were cleared in the Amazon River basin, which accounts for ____ percent of the Brazilian Amazon rain forest
50 million; 14 percent
______ activities account for ____ percent of global soil degradation
Agricultural activities account for 28 percent of global soil degradation
If this rate was constant, how much top soil would be lost every 25 years?
An inch of top soil, (0.4 inches x 25 years)
Why is deforestation underreported?
Because of Brazil's international debt
How much have humans elevated the extinction rate?
By at least 1000 x, and there are estimates that this number is between 1,000 - 10,000
What are the three states that consume the most water?
CA, TX, FL about 25 percent of withdrawals from our entire nation
Whats simpsons' biodiversity formula?
D= the sum of (n/N)^2
What are the 4 subsoils?
E, B, C, and R horizon
2 types of major soil in the US
Mollisoils and Utisoils
_____ estimated that in the 1980's _____ million hectares of tropical rainforest are destroyed each year
FAO; 13.7 million
What is forest degradation?
Forest degradation is broadly defined as a reduction in the capacity of a forest to produce ecosystem services such as carbon storage and wood products as a result of anthropogenic and environmental changes.
What is fragmentation?
Forest fragmentation is the process of breaking up large patches of forest into smaller pieces. This can be caused by many things, from clearing forest for roads or development to wildfire.
What is gully erosion?
Gully erosion occurs where surface water flow has become trapped in a small concentrated stream, and begins to erode channels in the ground surface.
Where is the greatest extent of loss of forests? Why?
In Africa, specifically Nigeria and Tanzania. Due to logging, substinence agriculture and a collection of fuel wood
Where are the majority of forests? Why is this a problem?
In developing countries, therefore it is hard to monitor and conservation is too expensive to fund.
Perceived value can have an affect on extinction. What does this mean?
It means like the perceived value of an animal or a plant, example is poaching
At the current rate, how many years would it take to lose all 6 productive inches of top soil that took _____ years to make?
It would take only 150 years to lose all 6 productive inches of top soil that took 3000 years to make
Define land degredation
Land degradation is a process in which the value of the biophysical environment is affected by a combination of human-induced processes acting upon the land.
Who introduced the concept of hotspots?
Norman Myers
What are the two top soils?
O and A horizon
What are the 6 layers of soil?
O horizon, A horizon, E horizon, B horizon, C horizon, and R horizion
What is a biological corridor?
Passes through which species can move from reserve to reserve without crossing an excessively human-dominated landscape
What are the three main drivers and agents of deforestation?
Swidden agriculture, commercial logging, and cattle ranching
What are temperate forests?
Temperate forests correspond to forest concentrations formed in the northern and southern hemisphere, or in temperate regions. Main characteristics include: wide leaves, large and tall trees and non seasonal vegetation
What are Boreal Forests?
The Boreal Forest is immense, spanning the globe 6.5 million square miles across northern regions of Russia, Scandinavia, Canada and Alaska
What is species richness?
The balance between immigration and extinction rates
What act prohibits any person from killing or even harming an ____ _____ or significantly altering the habitat that the species requires for survival?
The endangered species act
What is parent materal
The material in which a soil forms
Loss of hotspots could be called, what?
The sixth mass extinctions
What are the three greatest threats to biodiversity?
fragmentation, degradation, and the complete loss of ecosystems
How much does federal/federal dredging costs per year?
about $1 billion
Zone of saturation
area with no water within its pores
How can lightly degraded soils be improved?
by farm practices such as crop rotation and minimum tillage techniques
What are the penalties for breaking the endangered species act?
civil and criminal penalties
Agriculture runoff causes ___ ____ tons of topsoil loss annually
one billion
Sediment is an _____ barrier for ____
optical barrier for sunlight
At what zone does the oxygen sag begin to happen?
decomposition zone
Define ecosystem diversity
determined by the species composition, physical structure, and processes within an ecosystem
Australia has seen forest degradation, not only due to deforestation, but also due to ____ and _____ _____
drought and forest fires
What is an ecological footprint?
ecological footprint documents a given populations consumption and waste production expressed in biologically productive land and ocean areas necessary to maintain these services - ex. access to public transportation, renewable energy, energy efficient housing.
When bio capacity ratio is > 1, ______ is greater than _____ of the plant
ecological footprint is greater than the biodiversity of the planet
Almost ___ of the worlds forests are gone and up to ___ percent of coral reefs have been destoryed
half; 10 percent
The greater the D value, the ____ the diversity
higher
What is anthropogenic extinction?
human induced
Define genetic diversity
includes looking at the genetic differences within an individual species - ex. breeds of livestock
what is a sustainable footprint?
living and using the right amount of natural resources that are renewable so that the earth can replenish to support life in the future
Define endangered species
number very low, distinction is eminent
All water on earth: 98% ______ and _____, and 2% ____ ____
oceans and saline lakes, and 2 percent fresh water
the clean water act established a ____ system that must be used for ___ ____ of pollution. What facilities/operations were most affected by the clean water act?
permit system that must be used for point sources of pollution, such as industrial facilities, gov't facilities, and agricultural operations
Define threatened species
population low, extinction rates less eminent
Define ecological succession
process by which organisms occupy a site and gradually change environmental conditions by creating soil, shade and shelter
What will happen if current rates of deforestation continue?
rain forest will vanish in 100 years
What is clear cut logging
remove all trees at one time in a specific area
Global soil loss impacts our ability to meet, what?
rising food demands
What is zone of aeration
soil particles are filled with both water and air, it's where most plants obtain their water
Water table
the boundary between the zone of aeration and the zones of saturation
Define deforestation
the clearing of forests for other land uses, such as agriculture, grazing and new settlements
Define Endemics
the degree to which species are found only in a given place
define background extinction
the standard rate of extinction in Earth's biological and geological history before humans were a primary contributor to extinctions, for reasons such as change, disease, loss of habitat, or competitive disadvantage
Biodiversity
the variety of life on Earth and the natural distribution and patterns of organisms
Islands are so _____ diverse. They have _____ life forms found nowhere else on earth
topographically; 10,000
____ are megadiverse zones
tropics
Is more biodiversity near warmer or colder weather?
warmer