Notes 11-2

11.2 Water Use and Management
What is one of the worlds’ most pressing environmental problems?
A shortage of clean, fresh water
According to the World Health Organization how many people lack access to a clean, reliable source of water?
1 billion
Global Water Use
What are the three major uses of water?
Residential, agricultural, industrial
What is most water used worldwide for?
Irrigate crops
What affects how people use water?
Availability of fresh water, population sizes, economic conditions
How do Asia and Europe use water differently in agriculture?
Agriculture is 80% of use in Asia = only 38% use in Europe
What % of the water is used for industry in the world?
19
What is about 8% of the water used worldwide for?
Household activities such as drinking and washing
Residential Water Use
How much water does the average person in the US use every day?
300 L (80 gallons)
What activities inside the house is water used for?
Drinking, cooking, washing, toilet flushing
What activities outside the house is water used for?
Watering lawns, washing cars
Water Treatment
What is potable water?
Water that is safe to drink
What elements are removed from treated water?
Mercury, arsenic, lead
What is a pathogen and give examples?
Organisms that cause illness or disease.  Bacteria, viruses, protozoa, and parasitic worms are examples
What is the only continent that uses more water for industry than agriculture?
Europe
What is the second leading use of daily water in the US?
Toilet flushing
In a treatment plant what is added to water to form sticky blobs?
Alum
What are the sticky blobs called and what is their purpose?
Flocs, bacteria and other impurities cling to flocs, and settle to bottom of tank
Why is chlorine added to water?
Prevent bacteria from growing in the water
Why is air forced through the water as it is treated?
Release unwanted gases, reducing odor and improving taste
Why may fluoride be added?
Prevent tooth decay
What can be added to soften hard water?
Sodium compounds or lime
Industrial Water Use
What 5 major industrial uses of water were classified?
Manufacture goods, dispose of waste, generate power, produce computer chips and semiconductors, cool power plants
How much water is needed to manufacture a car?
500,000 Liters
What is most water in industry used for?
Cool power plants
Agricultural Water Use
How much water does it take to produce one of corn and what is that equal to?
300 L (80 gallons), average person in US use per day
What % of water use in agricultural use worldwide?
67%
What happens to 80% of water used in agriculture?
Evaporates and never reaches plant roots
Irrigation
Why is irrigation used?
Rainfall is inadequate

What is irrigation?
Method of providing plants with water from sources other than direct precipitation
How is cotton irrigated?
Shallow, water filled ditches
What is the most common irrigation method in the US?
Overhead sprinklers
What is wrong with this method of irrigation (US)?
Inefficient – nearly half the water evaporates
Water Management Projects
What is an aqueduct?
Huge canals that brought water from mountains to the dry areas of Spain and France
What were examples of water management projects?
Dams, water diversion canals
What were some goals of water management projects?
Bringing water to make dry area inhabitable, creating a reservoir for recreation or drinking water, generating electric power
Water Diversion Projects
Explain what happens to the Colorado River from its beginning until it flows into the Gulf of Mexico?
Begins as glacial stream in Rocky Mountains and grows larger as flows south – it is divided to meet needs of seven western states and so much is diverted that it often runs dry before it reaches Gulf of California
Dams and Reservoirs
What is a dam?
Structure built across a river to control the river’s flow
What is a reservoir?
An artificial lake that forms behind a dam
What six things can reservoirs be used for?
Flood control, drinking water, irrigation, recreation, industry, generate electrical energy
What produce electricity from water and how much of the world’s electricity comes from this?
Hydroelectric dams that use flowing water to turn turbines to generate electricity– 20%
How do dams affect land behind them?
People displaced (50 million worldwide), entire ecosystems destroyed
How does a dam affect areas below them?
Fertile sediment is stopped from enriching soil downstream
Why would dam failure be a problem?
People living downstream can be killed
Where are most large dam constructions occurring?
Developing countries such as Brazil, India, and China
Water Conservation
Why does water become more expensive as it becomes depleted?
Wells must be dug deeper, water must be piped greater distances, polluted water must be cleaned up before it can be used
Water Conservation in Agriculture
Where does most water loss come from in agriculture?
Evaporation, seepage, and runoff
How does drip irrigation work and what is the advantage?
Deliver small amount of water directly to plants roots by using perforated tubing, water is released to plants as needed and at a controlled rate – loses very little water to evaporation, seepage, or runoff
Water Conservation in Industry
What is the most widely used way of conserving water in industry?
Recycling of cooling water and wastewater
Water Conservation at Home
What is one-third of water used in US household used for?
Landscaping

What two technologies can be used in the household to save water?
Low-flow toilets and shower heads
When do people water lawns to conserve water?
Night
What is xeriscaping?
Designing a landscape that requires minimal water use
Solutions for the Future
What were two possible solutions to prevent water shortages?
Desalination and transporting fresh water
Desalination
What is desalination?
Process of removing salt from salt water
Where are many of these plants and what is the drawback?
Drier parts of the world, such as Middle East, consumes a lot of energy and is expensive
Transporting Water
What are some scientists proposing to get water from Alaska to California?
Fill huge bags with water from Alaskan rives and tow down coast to California
Where is 76% of the earth’s water?
Frozen in icecaps
What is the other way people have considered getting freshwater and what is the drawback?

Towing icebergs to communities that lack water, no efficient way to tow icebergs
No comments:

Notes 9.2

Section 2 Changing Population Trends

What do populations that have high rates of growth create?
Environmental problems, use resources at an increased rate and overwhelm infrastructure

What are infrastructure and give examples?
Basic facilities and services that support a community - public water suplies, sewer lines, power plants, roads, subways, schools, hospitals

What are the symptoms of overwhelming population growth?
Suburban sprawl, overcrowded schools, polluted rivers, barren land, inadequate housing

Problems of Rapid Growth

What can people not live without?
Sources of clean water, burnable fuel, land that can be farmed to produce food

When do standards of living decline?
When wood is removed from local forests faster than it regows or when wastes overwhelm local water sources

What are the resources most critically affected by rapid growth?
Vegetation, water, and land

In 2000, how much land would each person in the world get?
About 7.3 acres

In 2050 how much would they get?
4.8 acres

A Shortage of Fuel Wood

In poorest countries what is the main source of fuel?
Wood

How is wood for fuel important?
Can boil water and cook food - sterilized by boiling - food not cooked is often unsafe or hard to digest - without fuel wood many people suffer from disease and malnutrition

Unsafe Water

In places lacking infrastructure what may the water supply be used for?
Drinking and washing and sewage disposal

What is the result of these uses?
Water becomes breeding ground for organisms that cause diseases such as dysentary, typhoid, and cholera



How many people lack safe drinking water?
Over 1 billion

How many people died from diseases that were spread through water?
3 million

What happened in Peru in 1991?
First epidemic of cholera in western hemisphere in 75 years

Impacts on land

Where do people prefer to live?
Where they have easy access to resources and a comfortable lifestyle

What is arable land?
Land that can be used to grow crops

What is urbanization?
More people living in cities than in rural areas

What does suburban sprawl lead to?
Traffic jams, inadequate infrastructure, and reduction of land for farms, ranches, and wildlife habitat, housing within cities becomes more costly, more dense, and in shorter supply

A Demographically Diverse World

What terms do demographers prefer to use and why when describing countries?
More developed, less developed - complex and politically sensitive

What are least developed countries?
Countries that show signs of development and in some cases have increasing death rates while birth rates remain high

Where is most of the world’s population?
Asia

Managing Development and Population Growth

What will continued population growth prevent in less developed countries?
Imitating the development of the world's economic leaders

What countries have created campaigns to reduce fertility rates?
China, Thailand, and India

What do these campaigns include?
Public advertising, family planning campaigns, economic incentives or legal punishments

Growth is Slowing

What is the human population size now?
Over 6 billion

What has happened to fertility rates since 1970?
Declined in both more and less developed regions - rates much higher in less developed countries

What could possibly happen by 2050?
Most countries will have replacement level fertility rates and population growth would eventually stop

Projections to 2050

What will the world’s population be in 2050?

9 billion

No comments:

Notes 8.2

Section 2 – How Species Interact with Each Other
An Organism’s Niche
What is a niche?
  • The unique role of a species within an ecosystem
What does a niche include?
  • Species physical home, the environmental factors necessary for the species’ survival,  and all of the species’ interactions with other organisms
What is a habitat?
  • An organism’s location
How is a niche related to habitat?
  • Niche is a pattern of use of an organism’s habitat
What niche of large grazing herbivore is similar in which two species?
  • American bison and kangaroo – large grazing herbivore
Ways in Which Species Interact
How are interactions between species categorized?
  • At the level where one population interacts with another
What are the 5 major types of interactions?
  • Competition, predation, parasitism, mutualism, commensalism
What are the categories of interactions based on?
  • Whether each species causes benefit or harm to the other species
Competition
What is competition and what is its result?
  • Relationship in which different individuals or populations attempt to use the same limited resource – each individual has less access to resources and so is harmed by the competition
How can competition occur?
  • Within and between species
How do members of the same species compete?
  • Require same resources – same niche
What is called when two species compete?
  • overlap
Indirect Competition
Explain how species can compete even if they never come into direct contact with each other?
  • If two species use the same resource, but at different times of the day
Adaptations to Competition
What is one of the ways competition can be reduced between species?
  • Dividing up the niche in time or space
What is niche restriction and when is it observed?
  • When each species uses less of the niche than they are capable of using, in closely related species that use the same resources within a habitat
Explain how the barnacles use niche restriction?
  • Two species of barnacles divide space.  One (C. stellus) is found in upper level of intertidal zone and other in deeper (S. balanoides).  When deeper one is not present the upper level one (C. stellus) will occupy all levels
Predation
What is a predator?
  • An organism that feeds on another organism
What is prey?
  • The organism that is fed upon
In complex food webs what may happen to predators?
  • They may become prey
What have most organisms evolved against predators?
  • Mechanisms to avoid or defend against predators
Explain how the Canadian lynx and the snowshoe hare are linked?
  • Lynx feeds mainly on hares and so its population shows linked patterns – as one goes up so goes the other and vice versa
Case Study – Predator Prey Adaptations
Since most organisms are vulnerable to predation, what is there pressure for?
  • Adaptations that serve as defenses against predators
What is camouflage?
  • Disguise so that organisms are hard to see even when they are in view
What were the examples of camouflage?
  • Black stripes across the eyes, dark bands of color
What animals wait for their prey and how are they camouflaged?
  • Praying mantises and frogs – so prey does not notice them waiting to attack
What often contain toxic chemicals?
  • plants
What do animals with toxic defenses usually have?
  • Striking coloration
Which predators does warning coloration work well against?
  • Ones that can learn and that have good vision
What is mimicry and its advantage?
  • When one species resembles another – the more individual organisms that have the same pattern, the less chance of any one organism being killed.  Predator also learn to avoid all animals with similar warning patterns
What is a simple defense against predators and give examples?
  • Protective covering, quills of porcupine, spines of cactus, shell of turtle
Parasitism
What is a parasite?
  • An organism that lives in or on another organism and feeds on the other organism
What is a host?
  • The organism the parasite takes its nourishment from
What is parasitism?
  • The relationship between the parasite and its host
What are examples of parasites?
  • Ticks, fleas, tapeworms, heartworms, bloodsucking leeches, and mistletoe
Why do parasites usually not kill its host?
  • Have an evolutionary advantage if they do not
What may happen to the host because of the parasite?
  • Weakened or exposed to disease
Mutualism
What is mutualism?
  • A close relationship between two species in which each species provides a benefit to the other
What do mutualistic bacteria in you intestine do for you?
  • Help break down food you could not digest, produce vitamins your body could not
What do you do for them?
  • Warm, food-rich habitat

How are the acacia trees and the ants mutualistic?
  • Trees provide ants shelter and food , ants defend the trees against herbivores and other threats
Commensalism
What is commensalism?
  • Relationship in which one species benefits and the other species is neither harmed nor helped
How are remoras and sharks commensalistic?
  • Remoras attach to sharks and feed on scraps or food left over from shark’s meals
How are birds nest in trees commensalistic and how could it possibly not be?
  • If birds do not cause harm to trees – might cause damage to tree
Symbiosis and Coevolution
What is symbiosis?
  • A relationship in which two organisms live in close association
Why do organisms coevolve?

  • To reduce the harm or improve the benefit of the relationship
No comments:

Notes 8.1

Section 1 How Populations Change in Size

How many elephants could a single pair theoretically produce in 750 years?
19 million

Why is this number actually limited?
By their environment

What is a Population?

What is a population?
All the members of a species living in the same place at the same time

Why is a population also considered a reproductive group?
Because organisms usually breed with members of their own population

What two things does population refer to?
The group in general and to the size of the population

Properties of Populations

What three ways can populations be described?
Size, density and dispersion

What is population density?
Number of individuals per unit of area or volume

What is dispersion and what are the types of dispersion?
Relative distribution of its individuals within a given amount of space – even, clumped, random

How Does a Population Grow?

How do populations gain or lose individuals?
With births or deaths

What is growth rate?
A change in the size of the population over a given period of time

What is the equation for the growth rate?
Growth rate = births - deaths

What things can growth rates be (explain)?
Positive, negative, or zero.
Zero is equal number of births and deaths
Positive more births than deaths
Negative more deaths than births



How Fast Can a Population Grow?

Why do populations usually stay the same year to year?
Various factors kill many individuals before than can reproduce

What do the various factors control or determine for populations?
How the population evolves

Reproductive Potential

What is biotic potential?
The fastest rate at which its population can grow

What is reproductive potential?
The maximum number of offspring that each member of the population can produce

How does reproductive potential increase and what has the greatest effect?
Individuals produce more offspring at a time, reproduce more often, and reproduce earlier in life – reproducing earlier in life

What is generation time?
The average time it takes a member of the population to reach the age when it reproduces

As a general rule, how do organisms with small generation times compare to larger organisms?
Smaller organisms have shorter generation times

Exponential Growth

What is exponential growth?
When populations grow faster and faster – a larger number of individuals is added in each succeeding time period

When does exponential growth occur in nature?
When populations have plenty of food and space and have no competition or predators

What Limits Population Growth?

What things limit growth?
Resources are used up or the environment changes and deaths increase and births decrease

Carrying Capacity

What is carrying capacity?
The maximum population that the ecosystem can support indefinitely

Why is carrying capacity hard to predict?
Because ecosystems change

How is carrying capacity estimated?
Looking at average population size or by observing a population crash after a certain size has been exeeded

Resource Limits

When does a species reach its carrying capacity and what is this called?
When it consumes a particular natural resource at the same rate at which the ecosystem produces the resource – limiting resource

What determines the carrying capacity of an environment?
The supply of the most severely limited resource

Competition Within a Population

Why do members of a population compete?
Use the same resources in the same ways

What may individuals compete for indirectly?
Social dominance or territory

What is territory and why is it important?
An area defended by one or more individuals against other individuals – space, food, shelter, breeding sites

What is competition part of the pressure for?
Natural selelection

What things do organisms spend a large amount of time and energy competing for?
Mates, food, or homes


Two Types of Population Regulation

What are the two causes of death in populations?
Density dependent or density independent

What is density-dependent regulation and explain how it occurs with examples?
Deaths occur more quickly in a crowded population than in a sparse population – limited resources, predation and disease result in higher rates of deaths in dense populations

What is density-independent regulation and explain how it occurs with examples?
When a certain proportion of the population may die regardless of the population density – affects all populations in a uniform way.  Severe weather and natural disasters


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