| Midterm Review Project | Chapter 4-14 | | | 1/16/2014 |
AP ENVIRONMENTAL SCIENCE

CHAPTER 4
EARTH SYSTEMS AND RESOURCES I. The Nature of Ecology a. Ecology is the study of connections in nature i. Ecology is the study of how organisms interact with one another and with their non-living environment ii. An organism is any form of life. The cell is the basic unit of life in organisms. b. Population i. Members of a species interact in groups called populations. ii. Species of the same population live together in a particular place or habitat. c. Communities and Ecosystems i. A community consists of populations of different species living and interacting in an area ii. An ecosystem is a community interacting with its physical environment of matter and energy.

II. The Earth’s life support systems a. The different spheres of life-parts of Earth that support life systems. i. The Earth is made up of interconnected spherical layers that contain air, water, soil, minerals, and life.
i.i Atmosphere: thin envelope or membrane of air around the planet. Its inner layer is the troposphere; it extends only about 17 km above sea level. i.ii Stratosphere: subsequent layer; its lower portion contains ozone to filter out the sun’s harmful UV radiation. i.iii The hydrosphere consists of the Earth’s water . It is found as liquid water, ice, and water vapor in the atmosphere. i.iv The lithosphere is the Earth’s crust and upper mantle. It contains nonrenewable fossil fuels, minerals, and renewable soil chemicals. i.iv The biosphere is the portion of the earth in which living organisms exist and interact with one another and their nonliving environment. b. Elements that sustain life on Earth i. Solar energy: one-way-flow of high quality energy from the sun, into the environment as low quality energy, and eventually back into space as heat. ii. The cycling of matter: cycling of matter through parts of the biosphere iii. Gravity sustains the Earth’s life: allows the planet to hold onto its atmosphere and causes the downward movement of chemicals in the matter cycle. III. Ecosystems Components a. Biomes and Aquatic life zones i. Life exists on land systems called biomes. ii. Life exists in freshwater and ocean aquatic life zones. b. Major components of ecosystems. i. Ecosystems consist of living( biotic) and nonliving( abiotic) components c. Factors that limit population growth i. Limiting factor principle: too much or too little of any abiotic factor can limit or prevent growth of a population, even if all other factors are at or near the optimum range of tolerance. ii. Precipitation is a limiting factor on land iii. Soil nutrients is also a limiting factor on land iv. For aquatic ecosystems temperature, sunlight, nutrient availability, and dissolved oxygen content are limiting factors. d. Biodiversity i. Biological diversity is one of the Earth’s most important renewable resources. Kind of biodiversity include: i.i Genetic biodiversity : variety of genetic material i.ii Species diversity: number of species present in different habitats i.iii Ecological biodiversity : variety of terrestrial and aquatic ecosystems i.iv Functional biodiversity: biological and chemical processes such as energy flow and matter cycling needed for survival of species. IV. Soils a. Importance of Soils

i. Soil is a slowly renewed resource that provides most of the nutrients needed for plant growth and helps purify water. ii. Soil is the base of life on land because of this. b. Major layers in mature soils. i. Surface litter layer-O horizon: mostly freshly fallen decomposed or partially decomposed leaves, twigs, crop wastes, animal wastes, fungi, etc. i.i Topsoil layer-A horizon: porous mixture of partially decomposed organic matter( humus) and some inorganic mineral particles. i.ii B horizon: subsoil and the C horizon( lies on a base of unweathered parent rock contain most of a soil’s inorganic matter, mostly broken down rock consisting of varying mixtures of sand, silt, clay, and gravel Varying mixtures of sand, silt, clay, and gravel. c. Texture and porosity of soils i. Soils vary in the size of the particles they contain and the amount of space between particles. ii. Soil texture helps determine soil porosity which is a measurement of the volume of pores per volume of soil and the average distance between those spaces. V. Matter cycling in ecosystems a. Biogeochemical cycles i.
Hydrologic cycle: Recycles the Earth’s fixed supply of water
Carbon Cycle: Carbon, the basic building block of organic compounds, recycles through the earth’s air, water, soil, and living organisms.
Nitrogen cycle: Different types of bacteria help recycle nitrogen through the earth’s air, water, soil, and living organisms.
Phosphorus cycle: Fairly slowly through the earth’s air, water, soil, and living organisms.
Sulfur Cycle: Sulfur cycles through the earth’s air, water, soil, and living organisms VI. Primary productivity of ecosystems. a. Biomass produced i. The rate at which an ecosystem’s producers convert solar energy into chemical energy as biomass is the ecosystem gross primary productivity( GPP) ii. The rate at which producers use photosynthesis to store energy minus the rate at which they use some of this stored energy through aerobic respiration is called net primary productivity( NPP) b. NPP and limited population growth i. The number of consumers organisms the earth can support is determined by how fast producers can supply them with energy found in biomass

CHAPTER 5
EVOLUTION AND BIODIVERSITY (The living world) I. Origins of life a. Emersion of life i. The earth’s life is the result of about 1 billion years of chemical evolution to form the first cell, followed by 3.7 billion years of the biological evolution to form species we find on earth today. ii. Most knowledge about the past comes from fossils, chemical analysis, cores drilled out of buried ice, and DNA analysis. II. Evoultion and adaptation a. Evolution i. Evolution is the change in a population’s genetic makeup over time ii. All species descended from earlier, ancestral species. Life comes from life. b. Microevolution i. A population’s gene pool changes over time when beneficial changes or mutations in its DNA molecules are passed on to offspring. c. Natural selection i. It occurs when some individuals of a population have genetically based traits that increase their chances of survival and their ability to produce offspring with the same traits. ii. The process of microevolution can be summarized simply: Genes mutate, individuals are selected, and populations evolve. III. Ecological niches and adaptation a. Ecological niche i. Niche is a species way of life in a community and involves everything that affects its survival and reproduction. ii. Ecological niche is different from habitat( physical location where the species lives) iii. A species fundamental niche is the full potential range of physical, chemical, and biological conditions and resources it could use if there were no direct competition. b. Generalist and Specialist species i. Generalist species: Species with broad ecological niches; they can live in many different places, eat a variety of foods, and tolerate a wide range of environmental conditions. ii. Specialist species: Species with narrow niches; they may be able to live in only one type of habitat, use only one or a few types of food, and tolerate a narrow range of environmental conditions. More prone to extinction. c. Limits of adaptation i. A population’s ability to adapt to new environmental conditions is limited by its gene pool and how fast it can reproduce IV. Speciation, extinction, and biodiversity a. Evolution of new species. i. A new species arises when members of s population are isolated from other members so long that it changes in their genetic makeup prevent them from producing fertile offspring. ii. Speciation is the process in which natural selection under certain circumstances leads to an entirely new species. b. Extinction i. A species becomes extinct when its population cannot adapt to changing environmental conditions. ii. All species eventually become extinct, but sometimes drastic changes in environmental conditions eliminate large groups of species. ii.i Background extinction: as local environmental conditions change, a certain number of species disappear at a low rate. ii.ii Mass extinction: significant rise in extinction rates above the background level. It is catastrophic and widespread. ii.iii Mass depletion: extinction rates are higher than normal but not high enough to classify as mass extinction. V. The future of evolution a. Artificial selection i. Humans pick members of a population with genetic traits they like and breed them to produce offspring with such traits. b. Genetic engineering i. Genetic engineers create genetically modified organisms by transplanting genes from one species to the DNA of another species. c. Concerns about the genetic revolution i. Genetic engineering has great promise but it is an unpredictable process and raises a number of privacy, ethical, legal, and environmental issues.

CHAPTER 6
CLIMATE AND TERRESTRIAL BIODIVERSITY
(Earth systems and resources, the living world) I. Weather a. Weather. i. Weather is the result of the atmospheric conditions in a particular area over short time periods and is produced mostly by interacting masses. ii. Warm fronts: boundary between an advancing warm air mass and the cooler one it is replacing. iii. Cold front: leading edge of an advancing mass of cold air b. Highs and lows i. Weather is affected by up and down movements of masses of air with high( a high) and low( a low) atmospheric pressure. II. Climate a. Climate i. Is the average temperature and average precipitation of an area over long time periods of time, which in turn are affected by global air circulation. ii. Four majors factors determine global air circulation patterns: Uneven heating of the earth’s surface, seasonal changes in temperature and precipitation, rotation of the earth on its axis, and properties of air, water, and land. b. Ocean currents and winds affecting regional climates i. Ocean currents and winds influence climate by redistributing heat received from the sun from one place to another. c. Gases in the atmosphere i. Water vapor, carbon dioxide, and other gases influence climate by warming the lower troposphere and the earth’s surface. ii. The gases include H₂O, CO₂, CH₄, N₂O( greenhouse gases) iii. The natural warming effect of the troposphere is called the greenhouse effect. III. Biomes a. Organisms and their habitats i. Different climates lead to different communities of organisms. ii. The world is divided into 12 major biomes. iii. Biomes are terrestrial regions with characteristic types of natural ecological communities adapted to the climate of each region. b. Desert biomes i. Deserts have little precipitation and little vegetation. Desert is an area where evaporation exceeds precipitation. ii. Deserts are found in temperate, tropical, and Polar Regions. iii. They cover about 30 % of the earth’s land surface. IV. Grassland, tundra, and chaparral biomes a. Major types of grasslands i. Grasslands have enough precipitation to support grasses but not to support large stands of trees. ii. Savannas are hot places that have rain, except curing dry season, and enormous herds of hoofed animals. iii. Temperate grasslands cover vast expanses of plains and gently rolling hills. Cold winters and hot and dry summers with deep fertile soilswidely used for growing crops and grazing cattle iv. Polar grasslands are covered with ice and snow except during a brief summer, occur just south of the Artic polar ice cap. v. Chaparral is a temperate shrubland that has a wonderful climate but is subject to fires in the fall followed by flooding and mudslides. V. Forest Biomes a. Major types of forests i. Forests have enough precipitation to support stands of trees and are found in tropical, temperate and Polar Regions. ii. Tropical forests have heavily rainfall most days and have a diversity of life forms occupying a variety of specialized niches. iii. Temperate deciduous forests have trees that survive by dropping their leaves, which decay and produce a nutrient-rich soil. iv. Coniferous forests are seen in cold climates and consist mostly of cone-bearing evergreen trees that keep their needles year-round to help the trees survive long and cold winters. v. Temperate rain forests are coastal areas that support huge cone-bearing evergreen trees such as redwoods and Douglas fir in a cool and moist environment. VI. Mountain Biomes a. Importance of mountains i. Mountains are high-elevation forested lands of biodiversity ii. Often have snow-covered peaks that reflect solar radiation and gradually release water to lower-elevation streams and ecosystems.

CHAPTER 7
AQUATIC BIODIVERSITY
(The living world, Earth systems and resources)

I. Aquatic environments a. Two Major types of aquatic life zones i. Saltwater or marine life zones( estuaries, coastlines, coral reefs, coastal marches, mangrove swamps, oceans) ii. Freshwater life zones (Lakes, ponds, streams, rivers, and inland wetlands) b. Organisms that live in aquatic life zones i. Weakly swimming, free-floating plankton carried by currents. Plankton is divided into three types: phytoplankton( drifting), zooplankton( drifting animal), and ultra-plankton( photosynthetic bacteria) ii. A second group consists of strong swimming consumers (fish, turtles, and whales) nekton. iii. A third group, called benthos, dwells on the bottom( barnacles and oysters) iv. A fourth group consists of decomposers( mostly bacteria) that break down the organic compounds in the dead bodies. II. Saltwater zones a. Oceans i. Oceans occupy most of the earth’s surface and provide many ecological and economic services. b. Coastal Zone i. The coastal zone makes up less than 10 % of the world’s ocean area but contains 90% of all marine species. ii. It is the warm, nutrient-rich, shallow water that extends from the high tide mark on to the gently sloping, shallow edge of the continental shelf. c. Estuaries, coastal wetlands, and mangrove swamps i. An estuary is a highly productive area in the coastal zone partially enclosed where seawater mixes with freshwater and nutrients from rivers, and runoff from land. ii. Coastal wetlands are land areas covered with water all or part of the year. Include river mouths, inlets, bays, sounds, and mangrove forest swamps in sheltered regions along tropical zones. iii. The dominant organisms in mangrove forest swamps are trees that can grow in salt water. d. Barrier islands i. Narrow islands off some shores help protect coastal zones from storm waves, but developing these islands reduces this natural protection and makes them risky places to live. ii. Barrier islands are low, narrow, sandy islands that form offshore from a coastline. e. Coral reefs i. Coral reefs are biologically diverse and productive ecosystems ii. Coral reefs are increasingly stressed by human activities. III. Freshwater life zones a. Life zones found in freshwater Lakes i. Lakes consist of sunlit surface layer near and away from the shore, and at deeper levels a dark layer near a bottom zone ii. Lakes are formed when precipitation fill depressions in the earth’s surface glaciation, crustal displacement, and volcanic activities are causes of such depressions. iii. Lakes consist of four distinct zones: Littoral zone(high diversity, nutrient from bottom sediments, shallow sunlit waters near the shore depth to the depth at which plants stop growing), Limnetic zone( open sunlit water surface layer away from the shore, producers supply the food and O₂ that support most of the lake consumers). Profundal zone(deep, open water, too dark for photosynthesis, O₂ levels are low). Benthic zone( Mostly decomposers, detritus, fish swimming from zone to zone inhabit it, nourished by detritus that fall) b. Plant nutrients i. A lake’s supply of plant nutrients from its environment affect its physical and chemical conditions and types and numbers of organisms it can support. ii. Oligotrophic lakes: Newly formed with small supply of plant nutrient. iii. Eutrophic lake: large and excessive supply of nutrients (NO₃ and PO₄) needed by producers. iv. Mesotrophic lakes: those that fall between the two extremes of nutrient enrichment. v.
A: Source Zone
B: Transitional Zone
Floodplain Zone

CHAPTER 8 COMMUNITY ECOLOGY (The living world) I. Community structure & Species diversity a. Community structure i. Biological communities differ in their physical appearance, the types and numbers of species they contain( species richness and evenness), and the ecological roles their species play( niches) ii. Latitude and pollution, habitat diversity, NPP, habitat disturbance, and time are factors that affect species diversity in communities. b. Number of species on islands i. Species equilibrium model/Theory of Island biogeography: A balance between two factors determines the number of different species found on an island. The rate at which new species immigrate to the island and the rate at which existing species become extinct on the island. ii. The number of species on an island is determined by how fast species arrive and old species become extinct, the island’s size, and how far it is from the mainland. II. Types of species a. Communities can contain several kind of speciesthat play different roles in a community i. Native species(those that normally live and thrive in a particular community), nonnative species(those that evolved somewhere else and then migrate or were introduced into a community),indicator species( those that serve as early warnings of damage or danger to a community), keystone species( those that help determine the types and numbers of various other species), and foundation species( those that can create and enhance habitats that can benefit other species). III. Species interaction a. Species interaction. i. Competition, predation, parasitism, mutualism, and commensalism are ways in which species interact and increase their ability to survive. ii. Competition is the competence between species for shared or scarce resources. iii. Predation is the interaction in which members of one species feed directly on all or part of living organisms. iv. Parasitism occurs when one species feeds on part of another organism, usually living on or in it. v. Mutualism is the interaction between two species in a way that benefits both. vi. Commensalism is a species interaction that benefits one species but has little or no effect on the other. b. Predators and prey i. Some predators are fast enough to catch their prey, some hide and lie in wait, and some inject chemicals to paralyze their prey. ii. Some prey escape their predators or have protective shells or thorns, some camouflage themselves, and some use chemicals to repel or poison predators. iii. In win- win relationships the predator and the prey benefit. iv. Parasites promote community biodiversity. IV. Ecological succession a. Communities in transition. i. Ecological succession is the gradual change of environmental conditions over time that lead to one group of species being replaced by other groups ii. Two types of ecological succession are primary succession and secondary succession which involve the gradual establishment of biotic communities on nearly lifeless ground( primary) ii.i Secondary succession is the establishment of biotic communities in an area where some type of biotic community that is already present. V. Ecological stability a. Complexity and sustainability i. Living systems maintain some degree of stability or sustainability through constant change in response to changes in environmental conditions. ii. There are three aspects of stability in living sytems. ii.i Inertia: ability of a living system to resist being altered ii.ii Constancy: ability of a living system to keep the numbers within the limits imposed by resources. ii.iii Resilience: ability of a living system to repair damage after and external disturbance that is not drastic. b. Complexity i. Complexity refers to the number of species in a community at each trophic level and the number of trophic levels in a community. CHAPTER 9 POPULATION ECOLOGY (Population, The living world) I. Population dynamics and carrying capacity a. Characteristics of a population. i. Populations change in size, density, and age distribution, and most members of populations live together in clumps or groups. ii. Three patterns of population distribution in a habitat are clumping, uniform dispersion, and random dispersion. b. Factors that govern changes in population i. Populations increase through births and immigration and decrease through deaths and emigrations. ii. These actors depend on resource availability and other environmental changes. iii. Population change=( births + Immigration)-(deaths +emigrations) c. Population growth i. No population can grow indefinitely because resources are limited. ii. Populations vary in their capacity of growth which is the biotic potential of a population. iii. The intrinsic rate of increase(r) is the rate at which a population would grow if it had unlimited resources. iv. No population can grow indefinitely because resources such as light, water, and nutrients are limited. v. Carrying capacity is the maximum number of individuals of a given species that can be sustained indefinitely in a given space( area or volume) d. Population growth and carrying capacity i. When a population exceeds its resource supplies, many of its member die unless they can switch to new resources or move to an area with more resources. ii. When a population exceeds the carrying capacity of an area, it can cause damage that reduces the area’s carrying capacity. e. Population density i. A population’s density may or may not affect how rapidly it can grow. ii. Population density is the number of individuals in a population found in a particular space. iii. Density-independent population controls affect a population’s size regardless of its density iv. Density dependent population controls include competition for resources, predation, parasitism, and infectious diseases. II. Reproductive patterns a. Reproduction i. Some species reproduce without having sex and others reproduce by having sex. ii. Asexual reproduction: all of the offspring are exact genetic copies of a single parent( bacteria and species with one ceel0 iii. Sexual reproduction: organisms produce offspring by combining sex cells or gametes such as sperm and ovum from both parents( Combination of genetic traits) b. Reproductive patterns i. R-selected species: reproduce early and put most of their energy into reproduction i.e. algae, rodents, annual plants, and most insects. Many small offspring with little or no parental care. ii. K-selected species: tend to reproduce late in life and have a small number of offspring with fairly long life spans. The newborns mature slowly, are cared for and are born fairly large. III. Human Impact on Natural systems a. Humans and ecosystems i. Used technology to alter much of the rest f nature in ways that threaten the survival of many other species and could reduce the quality of life for our own species. ii. Destroying, using, wasting a great percentage of the earth’s net primary productivity that supports all consumer species. iii. Strengthened populations of pest species and disease-causing bacteria iv. Eliminated some predators v. Deliberately or accidentally introduced nonnative species into ecosystems.

CHAPTER 10 (Human Population) POPULATION ECOLOGY I. Factors affecting human population size a. Demography, death, life, and economies i. Population increases because of births and immigration, and decreases through deaths and emigration ii. The rate at which the world’s population is increasing has slowed. Population still growing fairly rapidly. iii. Pop. Growth= (Br-Dr)/10 b. Doubling time and the rule of 70 i. Doubling time is the measure of population growth. It is the time it takes for a population at a specified rate to double its size. ii. Rule of 70: used to calculate doubling time… 70/ percentage growth rate= doubling time in years c. Fertility and fertility rates i. Fertility is the number of births that occur to an individual woman in a population. There are two types: replacement level fertility and total fertility rate. ii. The factors that affect a country’s average birth rate are: importance of children as a part of the labor force, raising and educating children, availability of private and public pension systems, urbanization, infant mortality rate, and educational and employment opportunities available for women. d. Death rates i. Death rates have declined because of increased food supplies, better nutrition, and advances in medicine, improved sanitation, and safer water supplies. II. Population age structure a. Age structure diagrams and population growth. i. The number of people in young, middle, and older age groups determines how fast populations grow or decline. ii. The number of people under age 15 is the major factor determining a country’s future population growth. iii. Changes in the distribution of a country’s age groups have long-lasting economic and social impacts( Baby Boom-1946-1964) III. Demographic transition a. Demographic transition i. As countries become industrialized, first their death rates and then their birth rates decline. ii. It takes places in four stages: preindustrial stage( little pop. Growth, high death and birth rates), transitional stage( Industrialization begins, food production Health care improves, death rates drop rapidly, birth rates high), Industrial stage( birth rates drop eventually approaches death rates, modernization and medicine widely spread, pop. Growth cont. @ a slower , fluctuating rate), and the last stage is postindustrial stage( birth rates further declines = death rates, and zero pop. Growth birth rates fall below the death rate and pop. Size decreases slowly) b. Family planning i. Family planning provides educational and clinical services that help couples choose how many children to have and when to have them. ii. It has been a major factor in reducing the number of births and abortions throughout most of the world. c. Empowering women. i. Women tend to have fewer children if they are educated an, have a paying job outside the home, and do not have human rights suppressed.

CHAPTER 11 (Managing & protecting ecosystems) THE LIVING WORLD I. Human impacts on terrestrial biodiversity a. Human activities i. Human Pop. Human activities ( agriculture, industry, economic production and consumption, recreation) Direct effects( Degradation And destruction Of natural ecosystems, alteration of natural chemical cycles and energy flows, changes in number and distribution Of species, pollution of air, water, and soil) indirect effects(climate change and loss of biodiversity) ii. Biodiversity should be protected from degradation by human activities because it exists and because of its usefulness to us. II. Public lands in the U.S a. Major types of public lands. i. Federal public lands national forest system (managed by the U.S forest service) used for logging, mining, farming, livestock grazing, recreation, etc. ii. National resource land managed by the Bureau of Land Management. Used for mining, oil and gas extraction, and livestock grazing. iii. National Wildlife Refuges( managed by the U.S Fish and Wildlife Service) III. Managing and sustaining forests a. Major types of forests i. Old-growth forest: uncut forest or regenerated forest that has not been seriously disturbed by humans or natural disasters for at least 100 years. ii. Second-growth forest: stand of trees resulting from secondary ecological succession iii. A tree plantation or tree farm is a third type. It possesses unfirmly aged trees of one species harvested by clear cutting. b. Major types of forest Management i. Even-aged management: involves maintaining trees in a given stand at about the same age and size. ii. Uneven-aged management: involves maintaining a variety of tree species that stand at many ages and sizes. iii. Trees are harvested. Different ways: selective cutting, seed-tree cutting, clear-cutting, strip cutting. c. Deforestation i. Deforestation is the temporary or permanent removal of large expanses of forest for agriculture or other uses. ii. Human activities have reduced the earth’s forest cover by 20-50% . iii. The ways to manage forests more sustainably are: Grow more timber on long rotations, rely more on selective cutting and strip cutting, sharply reduce road building into uncut forests areas, include ecological services of trees and forests in estimating economic value. IV. Forest fires a. Surface fires and crown fires i. Surface fires usually burn only undergrowth and leaf litter on the forest floor. They kill seedlings and small trees, spare mature trees and allow animals to escape. ii. Crown fires usually occur in forests that have had no surface fires for several decades. They can destroy most vegetation, kill wildlife, increase soil erosion, and burn or damage human structures. V. Tropical deforestation a. Causes of tropical deforestation i. The primary causes of tropical deforestation and degradation are population growth, poverty, environmentally harmful government subsidies, debts owed to developed countries, and failures to value ecological services. VI. Reserves a. Reserves i. Large reserves usually are the best way to protect biodiversity, but well-placed, medium-size, and isolated reserves can do the job. ii. Biosphere reserves have an inner protected core surrounded by two buffer zones than can be used by local people for sustainable extraction of resources for food and fuel. b. Wilderness i. Wilderness consists of areas of undeveloped land affected primarily by the forces of nature, where man is a visitor who does not remain.

CHAPTER 12 (The species approach) THE LIVING WORLD, BIODIVERSITY I. Species extinction a. Types of species extinction i. Local extinction occurs when a species is no longer found in an area it once inhabited but is still found elsewhere in the world. ii. Ecological extinction occurs when so few members of a species are left that it can no longer play its ecological roles in the biological communities where it is found. iii. Biological extinction occurs when a species is no longer found anywhere on earth. II. Importance of wild species a. Value of wild species i. Wild species are useful to us in the form of economic and ecological services, and also provide us with recreational pleasures. III. Extinction threats from habitat loss and degradation a. Habitat loss and degradation i. The two primary causes of wildlife depletion and extinction are habitat loss, fragmentation, and degradation of habitat. ii. The basic causes of habitat loss and degradation are population growth, rising resource use, poverty, and no environmental accounting iii. The main secondary factors leading to premature extinction are habitat destruction and fragmentation(H), invasive species(I), population growth(P), pollution(P), and Overfishing(O) HIPPO. IV. Poaching and hunting a. Extinction threats from poaching and hunting i. Some protected species are killed for their valuable parts or are sold live to collectors. ii. Poverty is one reason behind illegal smuggling of wild species iii. As commercially valuable species become endangered their black market demand soars. V. Sanctuaries a. Wildlife refuges i. About 1/5 of U.S endangered species have habitats in the refuge system, and some refuges have been set aside for specific endangered species. ii. More than three-fourths of the refuges are concentrated along major bird migration corridors.

CHAPTER 13 (Sustaining aquatic Biodiversity) BIODIVERSITY I. Aquatic biodiversity a. Aquatic biodiversity i. Oceans support a variety of species at different depths. ii. Freshwater aquatic systems also contain a variety of visible plants and animal species iii. Humans know fairly little about the biodiversity of the world’s marine and freshwater systems. b. Patterns of marine biodiversity i. Coral reefs, coastal areas, and the ocean bottom are centers of marine biodiversity ii. Biodiversity is higher near coasts than in the open ocean iii. The lowest marine biodiversity is found in the middle depths of the open sea II. Human impact on aquatic biodiversity a. The greatest threat to the biodiversity of the world’s oceans is loss and degradation of habitats. b. Human activities have destroyed or degraded a large proportion of the world’s coastal wetlands, coral reefs, mangroves, and ocean bottom c. About three-fourth of the world’s commercially valuable marine fish species are overfished or fished near limits. III. Fisheries a. Solution to managing fisheries i. Set catch limits well below the maximum sustainable yield. Improve monitoring and enforcement of regulations. Restrict coastal locations for fish farms. Control pollution more strictly. Establish no-fishing areas. Establish more marine protected areas. ii. Use of wide-meshed nets to allow escape of smaller fish. Depend more on herbivorous fish species. Use net escape devices for seabirds and sea turtles. IV. Wetlands a. Protection of wetlands i. Some solutions to protecting wetlands are the legal protection of existing wetlands ii. Steer development away from existing wetlands iii. Use migration banking only as a resort iv. Restore degraded wetlands V. Rivers and lakes a. Lakes i. Invasion by nonnative species is a major threat to the biodiversity and ecological functioning of lakes. b. Rivers i. Rivers provide several ecological services and among these are: deliverance of nutrients to sea to help sustain coastal fisheries ii. Deposit silt that maintains deltas iii. Purify water iv. Provide habitats for wildlife CHAPTER 14 (Food and soil resources) BIODIVERSITY, SOIL I. Food production a. Stems that provide us with food i. Croplands, rangelands, and ocean fisheries supply most of our food. ii. Wheat, rice and corn provide more than half of the calories in the food consumed by the world’s people b. Agricultural systems i. There are two major types of agricultural systems: industrialized and traditional ii. Croplands provide important ecological and economic services II. Soil a. Soil erosion and degradation i. Water, wind, and people cause soil erosion ii. One type of land degradation is soil erosion which is the movement of soil components from one place to another iii. The harmful effects of soil erosion are the loss of fertility through depletion of nutrients and the pollution of water when soil sediment ends up in nearby surface water b. Desertification i. Desertification is the conversion of rangeland or cropland to desert-like land, with a drop in agricultural productivity of 10% or more. ii. It is a combination of drought and human activities III. Soil conservation a. Soil conservation i. Soil conservation involves using ways to reduce soil erosion and restore soil fertility ii. Many U.S farmers use conservation-tillage farming to disturb the soil as little as possible while planting crops. iii. Methods to reduce soil erosion are terracing, contour farming, strip cropping, and alley cropping IV. Food production and nutrition a. Under-nutrition i. People who cannot grow or buy enough food to meet their basic needs suffer from chronic under nutrition. ii. Many of the world’s poor suffer from malnutrition iii. The two most common nutritional deficiency diseases are marasmus and kwashiorkor. b. Over nutrition i. Over nutrition occurs when food energy intake exceeds energy use and causes excess body fat. ii. People who are underfed and underweight and those who are overfed and overweight face similar problems: lower life expectancy, greater susceptibility to disease and illness, and lower productivity and life quality c. Environmental effects of producing food i. A combination of these factors, soil erosion, salt built up and waterlogging of soil on irrigated lands, water deficit qnd droughts, and loss of wild species may limit the food production. V. Aquaculture a. Aquaculture i. Aquaculture involves raising fish and shellfish for food like crops instead of going out and hunting and gathering them. ii. Two basics types of aquaculture are known: fish farming and fish ranching iii. The advantages of aquaculture are: high efficiency, high yield in small volume of water, little use of fuel, high profits iv. The disadvantages of aquaculture are: large inputs of land, feed, and water needed, destroys mangrove forests, dense populations vulnerable to disease, and fish can be killed by pesticide runoff. VI. Sustainable agriculture a. Sustainable agriculture i. There are three ways to reduce hunger and malnutrition: to slow population growth, to reduce poverty, and to develop and phase in systems of more sustainable low-input agriculture ii. The ways to promote a sustainable agriculture are these: waste less food, reduce or eliminate meat consumption, use organic farming to grow some of our food, buy organic food, and compost our own food wastes.