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HCS 156 Notes Ecosystems Ecosystem- a grouping of plants, animals, and microbes interacting with each other and with their environment in such a way as to perpetuate themselves Types of Ecosystems - Land, aquatic, and transition zone Biome- A group of similar or related ecosystem. Large region characterized by (1) a distinct climate (2) specific forms of life adapted to it. Biosphere - Everything together. Structure of ecosystem  Categories of organisms  Feeding relationships  Mutualism  Abiotic (nonliving, not biologic) factors. Ex temperature, moisture, light Categories of organisms  Producers  Consumers  Detritus feeders and composers Autotrophs - make their own organic matter from inorganic nutrients and an environmental energy source. Heterotrophs - must feed on organic matter for energy. Examples of abiotic factors  Rainfall  Temperature  Light  Wind  Chemical nutrients  pH  Fire Optimum zone, zones of stress, & limits of tolerance  Different species thrive under different conditions (types or amounts of abiotic factors) Law of Limiting Factors  Any one factor being outside the optimal range will cause stress and limit the growth, reproduction, or even the survival of the population Test question All of the following statements about chesapeake bay are true except: A. Its the largest estuary in the U.S B. It gets high grades (A+) for clarity and O2 C. Its worth $33 billion a year in revenue D. It has excess levels of nitrogen and phosphorus

All of the following statements about ecosystem energy flow are correct except: A. Starts from the external environment (the sun) to the plants, then to herbivores, carnivores, and top carnivores. B. There is energy lost (as waste heat) at each level. C. Energy biomass in the top consumers is greater than that in the primary producers The type of biome is influenced by climate. T/F A. True

B. false Feeding relationships  Fundamental movement of the chemical nutrients and stored energy from one organism or level to the next  All food chains lead through a series of steps Non Feeding relationships  Mutualism (aka symbiosis) o Two species interact in ways that benefit each other Competitive exclusion principle  Two species who attempt to compete for the same resource cannot coexist in the same niche  One species will always go extinct or be forced to evolve. How is competition avoided?  Each species tends to be specialized and adapted to its own habitat or niche  This is not true when an exotic species is introduced into the habitat The plight of lake Victoria Cichlids  Ones this was the most numerous fish in Lake Victoria  What Happened to change this?  In the 1950s the british colonist introduced fish farming such as the Nile Perch What was the main finding about cichlids of Lake Victoria?  They are voracious predators  They are the most numerous fish in the lake  Fish farming experiment and pollution nearly wiped them out.  All of the above Niche  What an animal feeds on  Where an animal feeds  Where an animal finds shelter  Where an animal nests Keystone species  A species that has a large effect on a community or ecosystem  The removal or destruction of this species will have serious ecological consequences. Temperature and precipitation = climate Coniferous forests  Climate varies o Boreal forest o Temperate rainforest  Coniferous trees present (spruce, fir, pine)  Large and small herbivores present. Tundra  Permanently frozen subsoil called permafrost  Rainfall is quite low  Animal life is limited  Dominant vegetation o Moss, lichens, grass, and small perennials Desert  Hot days & cold nights

 Rainfall is less than 10 inches per year  Thorny bushes & shrubs (plant life that requires minimal rainfall for survival)  Rodents, lizards, toads, snakes, etc. present Grasslands  Rich biological communities of grasses  Organic matter in the soil is high  Rainfall is not sufficient to sustain tree growth  Mammals and reptiles are present Tropical rain forests  Rainfall is frequent and heavy  Great diversity of towering trees  Exotic, colorful insects, amphibians, reptiles, and birds are very abundant Coastal ocean  Microscopic phytoplankton algae dominate productivity  Often located over a continental shelf Which Biomes are most productive?  Estuaries  Swamps & marshes  Tropical rain forest

The Human Population :Size and Distribution Population explosion  Population increased slowly and variably with periodic setbacks  World population ~7billion in 2012 Why are fewer people dying?  Improved sanitation & personal hygiene  nutritional/ diet improvements  Vaccinations  antibiotics/ improved medical technology What are some areas of Improvement?  More people have access to better water and waste system.  Increased enrollment in education o Especially important in girls What are the two best indicators of the health of a country?  Infant mortality rate (2014) o Monaco is best (1.8 deaths/ 1000 births) o Japan is 2nd in the world (2.1 deaths/ 1000) o Us among the worst of industrialized countries  55th (6.2 deaths/ 1000 births) Crude Birth Rates  It is the number of babies born per 1000 people per year

Represents a nation's tool for determining its level of economic development In 2012 o US rate = 13/1000 population Crude death rates  Annual number of deaths per 1000 population Why are we concerned about new diseases?  Humans live in new habitats exposing them to new diseases  The emergence of antibiotic resistant strains  The large number of people make them easily accessible host for disease  Air travel allows disease to spread fast Total fertility rate  The average number of children a women has over her lifetime One a country reaches its replacement fertility rate….  Population starts to decline  The population growth immediately stabilizes  Population growth continues for a number of years then stabilizes  

Factors affecting birth rates and fertility rates  Availability of reliable methods of birth control  Average level of education and affluence o Education and employment opportunities for women o Cost of raising and educating children  Infant mortality rates  Average marriage age  Availability of private and public pension  Availability of abortion  Religious beliefs, traditions, and norms Current Fertility rate  According to 2005 UN estimates, total fertility rate had dropped to 2.9.  Two factors were identified o Delay in marriage (jobs for women) o Increased use of contraception Effects of a growing population  Subdividing farms & intensifying cultivation  Opening up new lands for agriculture  Migration to cities  Illicit activities  Emigration & immigration  Impoverished women & children Two views of the problem  Malthus argued that excess population causes all of the other problems  Marx argued that unequal resource distribution & exploitation causes all the other problems. Poverty Cycle

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Overusing resources for survival More “little hands” needed to help the family in a depleted environment. Illiteracy Lack of contraceptives Dwindling resources divided among more people

Part 2 : Addressing the population problem Demographic transition  Economic development will cause the falling of both birth and death rates  Many reasons for this occurrence: o Realization that children are expensive o Combating of diseases (lower infant mortality) o Birth control is affordable World Bank  Agency of the united nations that lends money to developing nations for large scale projects Down sides of world bank  1.3 billion people remain in poverty  Illiteracy poor nutrition  Lack of quality water  Fertility rates are still high  Environmental degradation is still rampant How to control population Modern family planning movement  Fruits of philosophy, by Dr. Charles knowlton- 1832  Development of the diaphragm in 1840  Family planning, by margaret Sanger  Birth Control clinics, 1916 Family planning  Family planning helps couples have the number of children they want  Ensures “every child is a wanted child” Views on population control  Optimistic & pessimistic schools of thought: o 1. Focussing on development will take care of the situation and bring a balance automatically o 2. We need to focus on controlling population New direction for development  Education  Improving health  Making contraceptives available

 Enhancing income  Improving resource management What is microlending?  Among the poor, there is no money & no way to make money o Poor people are considered Microlending is a concept where small amounts of money are loaned to start small businesses  Often organized as a cooperative  Default rate is less than 3% Case study - India 1  First to nationalize family planning o Population in 1952 - 400 milion o Population in 2000 - 1.0 billion o Projected population in 2025 - 1.4 billion Case study - India 2  What happened? o Bureaucratic inefficiency and poor planning o Lack of financial support o Low status for women o Extreme poverty o Culture that prefers boys and large families Case study - India 3  90% of indian couple know about birth control but only 50% use it  Results of population growth o 20-40% of population is malnourished Case study - China 1  1979 - population control efforts o Those who agree to have 1 child gets rewards o Couples who have 2 or more get penalized o 81% chinese women use birth control o Fertility rate dropped from 5.7 (1972) to 1.8 (2002) o But, much environmental Damage has already been done Case study - China 2  2016 - one child policy ends o Families still need permits from the government or be forced to have an abortion Case study - Thailand  1971 annual growth rate of 3.2% o By 2006 only .7% o Fertility rate dropped from 6.4% to 1.7 %  Reasons for success o Government supported family planning o High literacy and jobs for women o Better health care for mothers and children Case study - Japan  1949 to 2004 total fertility rate fell 4.5 to 1.3 o % of older people growing o Population in 2010, 127.1 million (estimate) o Could drop by 65-90 million by 2090

o

Declining workforce, rising taxes

What about the US?  In 2014, fertility rate dropped to 1.86  Immigration accounts for ~40% of growth o 2010, >1,000,000 legal & ???? illegal  Should the US continue to allow large number of immigrants? Family planning & the Pro life Movement  Michael gerson is a conservative speechwriter who served in the bush administration WHat were the 5 major elements necessary to address the population explosion?  Education  Birth control  Enhancing income  Health care  Improving resource management What happens to a country's population growth once it reaches the fertility replacement rate?  Population continues to grow (population momentum)

SECTION 2 NOTES

ALL OF THE FOLLOWING STATEMENTS ABOUT THE CERRADO REGION OF SOUTH AMERICA ARE TRUE EXCEPT?  RISING INCOMES IN CHINA CREATE A DEMAND FOR CROPS GROWN IN BRAZIL  BIOLOGICALLY, IT WAS A TROPICAL WASTELAND OF NO VALUE  UNTIL RECENTLY IT WAS CONSIDERED UNSUITABLE FOR CROPS  THE APPLICATION OF LIME AND PHOSPHOROUS HAS IMPROVED YIELDS OF SOYBEANS AND OTHER CROPS What is the status of world food production and consumption?  Because of rapid population growth, the world food supplies can't keep up with consumption  Increased use of irrigation, fertilizer and improved crop varieties has eliminated hunger  We can always get enough seafood from ocean  Although there is a surplus of food, millions of people don't have enough to eat What are the two main agents that cause soil erosion?  pH and sunlight  Wind and water  Lightening and thunder  Tectonic shifts and earthquakes In the US, the most recent increases in agricultural productivity have come from?  Irrigation in arid areas  Building up soil reserves on farms  Cleaning forests for agriculture use new crop varieties;  use of fertilizers and pesticides Which of the following best describes sustainable farming?  Because of the low input of chemicals, it is hard for sustainable farmers to make a living.  The organic farmer gets a good income because of lower chemical costs and higher consumer demand  Sustainable farming uses fewer chemicals but more water than conventional methods. Malnutrition  In poor countries, people cannot afford to purchase nutritious foods, including meats, and vegetables Factors influencing food demand  Population growth  Rising personal incomes  Poverty  Over nutrition in the developed world  Uneven distribution Health impact of hunger  Malnutrition  Overnutrition  Nutritional deficiency diseases Nutritional deficiency diseases  Kwashiorkor o Protein deficiency o Affections million of children in tropical areas, especially africa  Marasmus o Overall protein and calorie depletion o Often seen in children o Thin, wasted appearance

Xerophthalmia (Blindness) o Deficiency of vitamin o associated with protein shortages  Anemia o Iron deficiency o Seen in children and women o Characterized by lack of energy and low levels of productive activity  Goiter o Swollen growth of the thyroid gland o Affects over 20 million people worldwide o Iodine deficiency The production and distribution of farming Subsistence farmers  Farmers of the developing world that use traditional agricultural methods for raising plants, animals, and food Issues involving modern industrialized agriculture  Shifting from animal labor to machinery  Increasing the use of fertilizers and pesticides  Irrigation  New crop varieties Environmental costs of agriculture  Fossil fuel  Soil erosion  Water pollution  Resistant pest varieties  Groundwater depletion  Drawback of super high yielding crop varieties Why should we care about dirt?  Good soil = good crops 

What makes soil fertile?  A root environment with o Oxygen o Proper pH (near neutral) o Low salt  Mineral nutrients o Phosphate, potassium, calcium o No leaching  Water holding capacity  LOW PERMEABILITY HOLDS MORE WATER Soils as an ecosystem  Soil texture and workability  Detritus + soil organisms = humus and topsoil  Soil enrichment and minerals

3 types of soil  Clay  Sand  Silt  LOAM = best soil

Vectors of disease  Mosquitos o Asian tiger mosquito o Flies and roaches o body / head lice o Rodents and their fleas o ticks Disease surveillance  Traps to see if mosquitoes carry west nile  Sometimes flocks of chickens are tested for disease The most recent concern is zika virus  Infection with this virus has been linked with micro Pesticides  Insecticides  Herbicides  Rodenticides Federal laws  Federal insecticide, fungicides, and rodenticide act (FIFRA passed in 1947 o FIFRA is weak and poorly enforced  Food quality protection act (FQPA) of 1996 5 classes of insecticides  Natural organic -chemicals extracted from plants (pyrethrum)  Chlorinated hydrocarbons (DDT) - stored in fat and persist in the environment  Organophosphates (OP) nerve toxins  Carbamates - similar to OP but less toxic  Microbial agents and biological controls - living organisms or their toxins that kills pests, e.g. Bacillus thuringiensis (BT) and parasitic wasps. If the 6 surviving flies mate, what will happen to our experiment?  The baby flies will be even more resistant Environmental impact of pesticide use  Development of resistance  Killing of beneficial species o Direct o Food web interruption  Environmental contamination o Groundwater contamination o Soil contamination o Threatens species survival Hazards to human health  Not only toxic to pests, but can be toxic to humans  Pesticides can be taken into the body through the mouth, skin, or respiratory system

 Symptoms of acute exposure include headache, weakness, fatigue, or dizziness  Children are at risk from chronic exposure How much would crop yield decrease without pesticides?  About 20 % 4 ways of using natural or biological pest control  Behavioral control (disrupt the lifecycle)  Control by natural enemies  Genetic control  Natural chemical control (pheromones) Integrated pest management (IPM)  Aims to minimize the use of synthetic organic pesticides  Combines 2 or more methods carefully integrated into a total program  The goal is not to eradicate the pests but to manage the pests and to protect the environment

Examples of alternatives to synthetic organic pesticides  Natural enemies  Pathogens and parasites ex. Bacillus thuringiensis (BT)  Sex attractants (pheromones)  Development of resistant host plant  Sterile male technique  Crop rotation  Sanitation Socioeconomic issues in pest management  Economic threshold vs. insurance spraying  Cosmetic spraying  Export of banned pesticides Food Protection Programs Which is the most common food infection in the US?  Botulism  Norovirus  Listeria  anthrax It is estimated that foodborne disease kills ____ people in the US each year.  Less than 100  Over 100 but less than 1000  3000 or more which bacteria present a special risk of spontaneous abortion in pregnant women?  Botulism  Norovirus  Salmonella  listeria Which bacteria produces a deadly toxin?

 Botulism  Norovirus  Salmonella  E.coli What caused pet deaths in March 2007?  Illegal additives from china in dog and cat food  Also put in baby formula What is the food feud?  GAO calls for restructuring the federal food safety system o Inconsistencies in assessing chemical risks o Lack of prosecutions for violations of chemical limits in food (or for other Violations too)

How many have gotten food borne illnesses?  Each year, foodborne diseases cause : o 6-65 million cases of gastrointestinal illnesses o 100,000 - 325,000 hospitalizations o 3,000 - 9,000 deaths  New pathogens are emerging  Familiar ones resistant to treatment How much does foodborne disease cost the us economy?  $152 billion per year in healthcare, workplace and other economic losses Which age groups are most likely to die from foodborne diseases?  Very young and very old people Other concerns:  National and global distribution of foods o Leaving many more people at risk  Chronic pesticide poisoning in the diet  New technologies applied to food o Irradiation o Hormones and antibiotics given to animal o Genetic engineering How many have food allergies?  The food itself can be risky for certain people o 2-4% of children under age 6 are allergic o 1-2% of adults  Types of foods most likely to cause problems 3 ways food can make us sick?  Natural toxins in food  Pesticides or other chemicals  Microbial contamination o Bacteria o Viruses o Parasites o fungi 2 classes of microbial foodborne disease  Food infection :caused by harmful organisms that are eaten and multiply in the intestines

Norovirus  Most common cause of gastroenteritis o OUTBREAKS HAVE BEEN ASSOCIATED WITH OYSTERS, RASBERRIES AND DELICATESSEN MEAT  SPREAD VIA FECAL 0RAL ROUTE FROM AN INFECTED CARRIER  SYMPTOMS :cramps, vomiting, diarrhea, some fever  Major problem on cruise ships Campylobacter  A frequent cause of foodborne disease o Some cases are caused by contaminated water o Causes diarrhea, abdominal pain, fever, nausea, and vomiting  Symptoms usually last for 2-5 days  Sources include beef, chicken and unpasteurized milk Salmonellosis  The most common bacterial foodborne disease in the US  Associated with eating poultry, meat, or eggs  Symptoms: abdominal pain, diarrhea, chills, fever, frequent vomiting and prostration Listeriosis  Very dangerous to pregnant women and infants  Most often associated with food processing plants and milk products  Refrigeration provides no assurance against bacterial multiplication  Grows vigorously at low temperatures Staphylococcus aureus  Violent disease onset  Found in cooked ham, salads of protein food (like egg salad), custard pastries, hollandaise sauce and warmed over food  Often thought to be the 24 hour flu Botulism  One of the most serious of all bacterial foodborne diseases  Most frequently associated with home canned, low acid foods (beans, corn, beets, spinach, and mushrooms)  Causes respiratory paralysis and is conside...