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