Environmental Science Course Information PDF

Environmental Science Biodiversity Air Pollution Depletion Global climate Habitat destruction change Habitat degradation Stratospheric ozone Extinction depletion Urban air p...

Environmental Science Biodiversity Air Pollution Depletion Global climate Habitat destruction change Habitat degradation Stratospheric ozone Extinction depletion Urban air pollution Acid deposition Outdoor pollutants Major 1 1 Indoor pollutants Environmental Noise Water Pollution Problems Sediment Nutrient overload Toxic chemicals Infectious agents Oxygen depletion Pesticides Oil spills Excess heat Suggested Instructions for the First Day of Classes Prepared by H.M. Mahmoud Vice Dean of Education and Students Affair Faculty Of Science Beni-Suef University ▸ Instructor contacts Prof. Abdel-Azeem S. Abdel-Baki Faculty Of Science, Beni-Suef University Email: [email protected] Office: 3rd floor Office hours: 3hours daily except Thursday  Course description and objectives ▸ Course name is Environmental culture code 1001- 1003 ▸ The goal of this course is to know more about our environment and focus on what we can do to sustain it and how deal with ecological problems ▸ It is a 2 credit course with 2 lecture hours per week for one semester ( no laboratory work).  Reading Materials Lecture notes Suggested Textbook: Environmental Science Principles of Environmental Science  Evaluation methods and deadlines ▸ All activities (i.e., exercises, tests, lab reports, and other assignments) are due by the end of the day on the dates announced in class. ▸ Assignments handed in late will be penalized 10% for each day they are late. ▸ Assignments more than 1 week late will not be accepted. ▸ There will be two midterms over the course of the term and a comprehensive final exam. ▸ All exams will have similar formats including multiple choice, matching, true or false, short answer, and essay.  Grade breakdown Item Weight Attendance and participation 30 Midterms and Quizzes 10 Final 60 Total 100  Attendance ▸ The ability to comprehend, condense and absorb spoken material is a vital skill emphasized in University life. ▸ Attendance will help you to improve your grade in regular exams ▸ As I will not match the lecture material exactly to the text, so you will want to hear it to be prepared for exams. ▸ You will be also graded on participation. ▸ There are no allowed absences without an excuse from the clinic or office of Student Affairs. ▸ Repeated absences may result in a failing grade or the recommendation that the students drop the course.  Make up Exams ▸ Make-up exams are available only under the most extreme circumstances. ▸ To miss a scheduled exam you must discuss it with me before the scheduled time ▸ If I agree that you have a valid excuse, you may take it early. ▸ If you miss a scheduled exam, without clearing it with me prior to the time it is scheduled, you may not make it up.  Cheating ▸ Cheating is dishonest and unethical. ▸ Students found cheating will be subject to University discipline, but at the minimum will leave this course with an F. ▸ Remember, each assignment must be your own work. ▸ Assignments that are so similar with each other will be considered cheating. ▸ You must cite the reference(s) you use in preparing your reports and assignment because if you didn’t it will be considered plagiarism.  Lecture courtesy ▸ The general rules of classroom etiquette are below. 1. Arrive on time, 2. Please avoid conversations with others in class while the instructor is lecturing, 3. Limit food to those that can be eaten quickly and quietly, 4. Please turn cell phones to silent while in class, 5. You may use laptop for note-taking; but chatting, email checking, facebooking, etc. are not allowed during class time.  My Email Policy ▸ Email communication should be limited to quick and easy-to- address questions. ▸ More difficult or involved questions should be discussed during lecture time or during office hours. ▸ NOTE: I rarely check email on weekends.  Lecture Schedule Week # Topic 1. Understanding Our Environment 2. Environmental Systems: Matter, Energy, and Life 3. Evolution, Species Interactions, and Biological Communities 4. Human populations 5. Biomes and biodiversity 6. Environmental Conservation: Forests, Grasslands, Parks, and Nature Preserves 7. Food and Agriculture 8. Nutrient & element cycles 9. Environmental Health and Toxicology 10. Climate change 11. Air pollution 12. Water: Resources and Pollution 13. Solid and Hazardous Waste 14. Economics and Urbanization 15. Environmental Policy and Sustainability Tools To Study The Environment The nature of environmental science The scientific method and the scientific process Natural resources and their importance Culture and worldviews Environmental ethics Sustainability The “environment” Consists of both: Biotic factors (living things) and Abiotic factors (nonliving things) that surround us and with which we interact. The Environment (Earth) Life has existed on earth for 3.8 billion years Earth well suited for life Water covers ¾ of planet Habitable temperature Moderate sunlight Atmosphere provides oxygen and carbon dioxide Soil provides essential minerals for plants But humans are altering the planet; not always in positive ways  Earth As a System System A set of components that interact and function as a whole Global Earth Systems Climate, atmosphere, land, coastal zones, ocean Ecosystem A natural system consisting of a community of organisms and its physical environment Systems approach to environmental science Helps us understand how human activities effect global environmental parameters  Earth Systems Most of earth’s systems are in dynamic equilibrium or steady state (resiliency). Rate of change in one direction equals that in the other Feedback Change in 1 part of system leads to change in another. Negative feedback- change triggers a response that counteracts the changed condition. Positive feedback- change triggers a response that intensifies the changing condition. Humans and the environment We humans exist within the environment and are a part of the natural world. Like all other species, we depend for our survival on a properly functioning planet. Thus, our interactions with our environment matter a great deal. Natural resources Renewable resources like sunlight cannot be depleted. Nonrenewable resources like oil CAN be depleted. Resources like timber and clean water are renewable only if we do not overuse them. Figure 1.1 Types of Natural Resources  Human Impacts on Environment Population Earth’s Human Population is over 6 billion Growing exponentially Expected to add several billion more people in 21st century Increase will adversely affect living conditions in many areas of the world www.census.gov/main/www/popclock.html Global human population growth Our population has skyrocketed to over 6 billion. The agricultural and industrial revolutions drove population growth. Figure 1.2 Population Globally, 1 in 4 people lives in extreme poverty Cannot meet basic need for food, clothing, shelter, health Difficult to meet population needs without exploiting earth’s resources  Overpopulation Human Overpopulation Too many people in a given geographic area Problem in many developing nations Consumption Overpopulation Each individual in a population consumes too large a share of the resources Problem in many highly developed nations  Gap Between Rich and Poor Highly Developed Countries (HDC) Complex industrialized bases, low population growth, high per capita incomes Ex: US, Canada, Japan Less Developed Countries (LDC) Low level of industrialization, very high fertility rate, high infant mortality rate, low per capita income Ex: Bangladesh, Mali, Ethiopia  Thomas Malthus (1766-1834) Population growth will lead to starvation, war, disease. Death rates check population unless birth rates are lowered. (Malthusianism) is the idea that population growth is potentially exponential while the growth of the food supply or other resources is linear, which eventually reduces living standards to the point of triggering a population die off. In our day, Paul Ehrlich (The Population Bomb, 1968) is called “neo-Malthusian” population control through the use of contraception is essential for the survival of the earth's human Figure 1.3 population The tragedy of the commons Garrett Hardin, 1968: In a “commons” open to all, unregulated use will deplete limited resources. Figure 1.4 An Example: Tragedy of the Commons Garrett Hardin (1915-2003) Solving Environmental Problems is result of struggle between: -Short term welfare -Long term environmental stability and social welfare Garrett used Common Pasture land in medieval Europe to illustrate the struggle.  Ecological Footprint The average amount of land, water and ocean required to provide that person with all the resources they consume “Metric that measures how much nature we have and how much nature we use” Earth’s Productive Land and Water 11.4 billion hectares Amount Each Person is Allotted 1.9 hectares (divide Productive Land and Water by Human Population) Current Global Ecological Footprint of each 2.3 hectares person  Environmental Sustainability The ability to meet current human need for natural resources without compromising the needs of future generations Requires understanding: The effects of our actions on the earth That earth’s resources are not infinite  Sustainable Development Economic development that meets the needs of the present generation without compromising future generations. ‫وتُجرى التنمية املستدامة يف ثالثة‬ :‫جماالت رئيسة هي‬ ‫النمو االقتصادي‬- ‫وحفظ املوارد الطبيعية والبيئة‬-.‫والتنمية االجتماعية‬- Environmental science How does the natural world work? How does our environment affect us? How do we affect our environment? Applied goal: Developing solutions to environmental problems. What is an “environmental problem?” Environmental issues are the problems with the planet's systems (air, water, soil, etc.) that have developed as a result of human interference or mistreatment of the planet. Definitions differ. The pesticide DDT: was thought safe in 1945 is known to be toxic today but is used widely in Africa to combat malaria Figure 1.5 What is an “environmental problem?”  Environmental Science An interdisciplinary study of human relationship with other organisms and the earth Biology Ecology Geography Chemistry Geology Physics Economics Sociology Demography Politics Environmental science … is an interdisciplinary field, drawing on many diverse disciplines. Figure 1.6 Environmental science … is NOT the same as environmentalism. It is science, NOT advocacy. Advocacy vs. Science The advocate: will pick up any piece of apparently useful data and without doing any analysis. Their conclusion is always that their original theory is correct. The scientist: will look at all possibilities and revise their thinking based on a thorough assessment of all issues. Their conclusion follows from Figure 1.7 the analysis whatever it points to. Science A systematic process for learning about the world and testing our understanding of it A dynamic process of observation, testing, and discovery And the accumulated body of knowledge that results from this process Applications of science The use of scientific knowledge for a specific purpose, whether to do more science; to design a product, process, or medical treatment; to develop a new technology; or to predict the impacts of human actions. classroom and engaging in engineering practices. Policy decisions and management practices are applications of science. Prescribed burning, used to restore forest ecosystems altered by human suppression Figure 1.8a of fire. Applications of science Technology is another application of science. Energy-efficient methanol-powered fuel cell car from DaimlerChrysler Figure 1.8b Scientific method: Assumptions The process of building scientific knowledge relies on a few basic assumptions that are worth acknowledging. Science operates on the assumptions that: Fixed natural laws govern how the universe works All events arise from causes, and cause other events We can use our senses and reason to detect and describe nature’s laws There are natural causes for things that happen in the world around us. Scientific method A step-by-step method for testing ideas with observations. Figure 1.9 Scientific Method Observations are anything you can sense? How do you sense things? See, hear, smell, touch, taste Scientific Method  Steps of the Scientific Method Ask a Question The scientific method starts when you ask a question about something that you observe: How, What, When, Who, Which, Why, or Where? For a science fair project some teachers require that the question be something you can measure, preferably with a number. Construct a Hypothesis A hypothesis is an educated guess about how things work. It is an attempt to answer your question with an explanation that can be tested. A good hypothesis allows you to then make a prediction: "If _____[I do this] _____, then _____[this]_____ will happen." State both your hypothesis and the resulting prediction you will be testing. Predictions must be easy to measure. Test Your Hypothesis by Doing an Experiment Your experiment tests whether your prediction is accurate and thus your hypothesis is supported or not. - It is important for your experiment to be a fair test. - You conduct a fair test by making sure that you change only one factor at a time while keeping all other conditions the same. - You should also repeat your experiments several times to make sure that the first results weren't just an accident. Analyze Your Data and Draw a Conclusion - Once your experiment is complete, you collect your measurements and analyze them to see if they support your hypothesis or not. - Scientists often find that their predictions were not accurate and their hypothesis was not supported, and in such cases they will communicate the results of their experiment and then go back and construct a new hypothesis and prediction based on the information they learned during their experiment. - This starts much of the process of the scientific method over again. Even if they find that their hypothesis was supported, they may want to test it again in a new way. Communicate Your Results - To complete your science fair project you will communicate your results to others in a final report and/or a display board. - Professional scientists do almost exactly the same thing by publishing their final report in a scientific journal or by presenting their results on a poster or during a talk at a scientific meeting. - In a science fair, judges are interested in your findings regardless of whether or not they support your original hypothesis. Scientific Method Observations must be Measurable Repeatable Controllable Controls and Variables in Experiment Variable A factor that influences a process The variable may be altered in an experiment to see its effect on the outcome Control The variable is not altered Allows for comparison between the altered variable test and the unaltered variable test Scientific Method Hypotheses are tentative explanations of the observations or educated guesses. Predictions result from hypotheses and are usually seen in the form of if then statements. For example, My car won’t start is an observation. The battery in my car is dead is a hypothesis. If I replace my car battery with a brand new battery then it will start is a prediction. Scientific method Scientists use educated guesses called hypotheses to generate predictions that are then tested experimentally. Results may reject or fail to reject a hypothesis. Results never confirm a hypothesis, but only lend support to it by failing to reject it. This means we never prove anything with this method. Experiments Manipulative experiments Natural or correlational are strongest. ones are often necessary. Figure 1.10 Scientific process Peer review, publication, and debate are parts of the larger scientific process. Figure 1.11 Hypothesis, theory, and paradigm Hypothesis = an educated guess, to be tested Theory = a well-tested and widely accepted explanation of the observations, validated by much previous research Paradigm = a dominant view. May shift if new results show old results or assumptions to be wrong Scientific Method Feedback is the most important feature of the scientific method. It allows for self reflection. It lets us look at the data from different points of view. It allows us to test different but related hypotheses. It creates opportunities to find multiple reasons to confirm our hypothesis. Inductive and Deductive Reasoning Inductive Reasoning Used to discover general principles Seeks a unifying explanation for all the data available Ex: FACT: Gold is a metal heavier than water. FACT: Iron is metal heavier than water. FACT: Silver is a metal heavier than water. CONCLUSION (based on inductive reasoning): All metals are heavier than water. Conclusions reached with inductive reasoning may change with new information. Inductive and Deductive Reasoning Deductive Reasoning Proceeds from generalities to specifics Adds nothing new to knowledge, but makes relationships (possible cause and effect) and associations (not cause and effect) among data more apparent. Ex: GENERAL RULE: All birds have wings. SPECIFIC EXAMPLE: Robins are birds. CONCLUSION (based on deductive reasoning): All Robins have wings. Five Stages to Addressing An Environmental Problem Five steps are idealistic Real life is rarely so neat, but it does allow for solutions. Following Slides are Case Study Using the Five Stages Assessing Environmental Problem Case Study: Lake Washington Scientific Assessment Aquatic wildlife assessment done in 1933 was compared to the 1950 assessment Hypothesized treated sewage was introducing high nutrients causing growth of cyanobacteria Risk Analysis After analyzing many choices, chose new location (freshwater) and greater treatment for sewage to decrease nutrients in effluent Assessing Environmental Problem Case Study: Lake Washington Public Education/Involvement Educated public on why changes were necessary Political Action Difficult to organize sewage disposal in so many municipalities Changes were not made until 1963! Evaluation Cyanobacteria slowly decreased until 1975 (gone) Assessing Environmental Problem Case Study: Lake Washington Results! Ethics Ethics is a discipline that deals with how we value and perceive our environment. Ethics influence our decisions and actions. Figure 2.1 Assessing Environmental Problem Case Study: Lake Washington Large, freshwater pond Suburban sprawl in 1940’s 10 new sewage treatment plants dumped effluent into lake. Effect = excessive cyanobacteria growth that killed off fish and aquatic life (nitrogen & phosphorous). Worldview Worldview = a person’s or group’s beliefs about the meaning, purpose, operation, and essence of the world. Some questions in environmental ethics Should the present generation conserve resources for future Are humans justified generations? in driving other species to extinction? Is it OK to destroy a forest to create jobs Is it OK for some for people? communities to be exposed to more pollution than others? Environmental Ethics Moral = the distinction between right and wrong Values = the ultimate worth of actions or things What is instrumental value? Valuable as a means to some end Ex. Washing machine What is intrinsic value? Valuable in itself Ex. Pleasure and happiness Environmental Ethics is concerned with the moral relationships between humans and the world around us. Do we have special duties, obligations, or responsibilities to other species or nature in general? Are our dispositions (actions) towards humans different than towards nature? How are they different? Are there moral laws objectively valid and independent of cultural context, history, situation, or environment? Environmental Ethics Universalists: ‫العالميون‬ Relativists:‫النسبيون‬ Nihilists: ‫العدميون‬ Utilitarians: ‫النفعيون‬ Environmental Ethics Universalists Fundamental principles of ethics are universal, unchanging, and eternal. The rules of right and wrong are valid regardless of our interests, attitudes, desires or preferences. Revealed by God? Revealed by discovery? Plato, Kant Environmental Ethics Relativists Moral principles are always relative to a particular person, society, or situation. Ethical values are contextual, that is they depend on the person, the society, or the situation. There is right and wrong or at least better or worse but no principles are absolute regardless of context. Sophists Environmental Ethics Nihilists The world makes no sense at all! Everything is completely arbitrary, there is no meaning or purpose to life other than the instinctive struggle for survival. There is no reason to behave morally. Schopenhauer Environmental Ethics Utilitarians An action is right that produces the greatest good for the greatest number of people. Goodness = Happiness Happiness = Pleasure Bentham (Plato, Socrates, Aristotle) John Stuart Mill held that the greatest pleasure is to be educated and to act according to enlightened, humanitarian principles Environmental Perspectives (World views) Worldview = a person’s or group’s beliefs about the meaning, purpose, operation, and essence of the world. There are lots of them Three ethical worldviews Biocentrism: It is an understanding of how the earth works, particularly as it relates to its biosphere or biodiversity Ecocentrism: is the broadest term for worldviews that recognize intrinsic value in all lifeforms and ecosystems themselves, including their abiotic components. Anthropocentrism: in contrast, values other lifeforms and ecosystems insofar as they are valuable for human well-being, preferences and interests. Environmental Perspectives Domination ‫هيمنة‬ Stewardship ‫الوكالة‬ Biocentrism ‫مركزية حيوية‬ Ecocentrism ‫مركزية البيئة‬ ‫النسوية البيئية‬ Ecofeminism ‫العملية العلمية‬ Scientific Process ‫االستدامة‬ Sustainability ‫التفكير النقدي‬ Critical Thinking Environmental Perspectives Domination “Be fruitful, and multiply, and replenish the earth, and subdue it; and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth” Gen 1:28 Stewardship Responsibility to manage and care for a particular place. As custodians of resources, they see their proper role as working together with human and nonhuman forces to sustain life. Humility and reverence are essential in this worldview Environmental Perspectives Biocentrism: It is an understanding of how the earth works, particularly as it relates to its biosphere or biodiversity Life centered, all organisms have some intrinsic values and rights. Biodiversity is the highest ethical value in nature. Individuals and populations are the basic units of biodiversity. Environmental Perspectives Ecocentrism Ecologically centered, because individuals are doomed to suffering and pain evolution, adaptation, and biogeochemical cycles are really more important than individuals. The whole ecosystem is more important than the individuals and populations that make up the ecosystem. Moral values for ecological process and systems Environmental Perspectives Ecofeminism: Ecofeminism is a branch of feminism that sees environmentalism, and the relationship between women and the earth, as foundational to its analysis and practice. Western civilization in opposition to nature life is interconnected maintenance of diversity restructuring human society Bounty rather than scarcity Cooperation rather than competition A network of personal relationships rather than isolated egos Environmental Perspectives The Scientific Process at work 1. Provides a linear path to knowledge with positive and negative feedback loops. 2. Requires repeated observation of the same thing, over and over again. 3. Some times repeated observations are not possible. 4. Need to be able to measure something. (testable?) 5. Need to be able to control things. 6. Need to be able to define things. 7. Can’t Prove something to be true only that it is false 8. Feedback goes on at each level in the scientific method. Environmental Perspective Sustainability Refers to whether a process can be continued indefinitely without depleting the energy or material resources on which it depends. Sustainable agriculture maintains the integrity of the soil and water resources as well as genetic diversity of the germ plasm. Sustainable development provides people with a better life without sacrificing or depleting resources or causing environmental impacts that will undercut future generations. Sustainable society sustainable yield. Environmental Perspective Sustainability based on ecosystem processes A recycling of elements Sunlight as a source of energy Carrying capacities are realized and maintained Biodiversity is maintained Environmental Perspectives Critical Thinking Elements of thought Intellectual standards Early environmental philosophers The industrial revolution inspired reaction. The preservation ethic John Muir (right, with President Roosevelt at Yosemite) advocated preserving unspoiled nature, for its own sake and for human fulfillment. Figure 2.5 The conservation ethic Gifford Pinchot advocated using natural resources, but exploiting them wisely, for the greatest good for the greatest number for the longest time. Figure 2.6 The land ethic Aldo Leopold urged people to view themselves as part of nature, and to strive to maintain “the integrity, stability, and beauty of the biotic community.” Figure 2.7 Environmental justice (EJ) Poor people and minorities suffer more than their share of environmental problems, EJ advocates say. The EJ movement began with a protest against a toxic waste dump in an African-American community in North Carolina. Figure 2.8 Sustainability The key concept for our future: Limiting human impact on the natural world so that our civilization can continue to exist Sustainable development UN: Development that “meets the needs of the present without sacrificing the ability of future generations to meet theirs”. Figure 1.17 Conclusions: Challenges We live on a planetary island with limited resources. Population and consumption are growing. Many feel that we have not yet developed the ethical basis for sustainability. Environmental justice remains a challenge. Conclusions: Solutions We are developing ideas and technologies to lessen our impacts. We can reduce population and consumption. Sustainability is catching on. Science helps us understand our world and develop solutions. Conclusions: Solutions Environmental science is vibrant and growing. Ethics evolve, and we may yet develop an ethical basis for sustainability. Advances in technology and efficiency can mitigate our environmental impacts. Advances have been made toward environmental justice. QUESTION: Review An anthropocentric worldview would consider the impact of an action on… ? a. Humans only b. Animals only c. Plants only d. All living things e. All nonliving things QUESTION: Review Which ethic holds that people should use resources “for the greatest good for the greatest number for the longest time”? a. Preservation ethic b. Land ethic c. Conservation ethic d. Deep ecology e. Biocentrism QUESTION: Weighing the Issues Which worldview is closest to your own? a. Anthropocentric b. Biocentric c. Ecocentric QUESTION: Review Which is a nonrenewable natural resource? a. Sunlight b. Petroleum c. Timber d. Freshwater QUESTION: Review Which statement is FALSE? a. Our environment includes living and nonliving elements. b. Thomas Malthus favored population growth. c. Environmental science includes multiple disciplines. d. Theories are better supported by evidence than are hypotheses. QUESTION: Review Which is NOT an application of science? a. Policy decisions b. Technologies c. Experimental results d. Management practices QUESTION: Weighing the Issues What do you think is the best way to combat the “tragedy of the commons”? a. Sell the commons into private hands, so owners have incentive to manage resources. b. Have government regulate the amount of resources individuals take from the commons. c. Have users work out cooperative systems among themselves to police resource use. QUESTION: Interpreting Graphs and Data What happens if results fail to reject a hypothesis? a. The hypothesis is proven to be true. b. The hypothesis is supported, but not confirmed. c. The hypothesis may be retested in a different way, with new predictions. d. Both b and c are true. Figure 1.9 ECOLOGY Ecology: Study of interactions between organisms and their environment. Environment includes both abiotic (non-living) and biotic (living) components. Abiotic: light, water, nutrients, chemicals, rocks, weather, etc. Biotic: organisms. Organisms compete with, parasitize, eat or are eaten by and change the environment for other organisms. Ecology explores a wide range of questions about what factors control the distribution, abundance and behavior of organisms. For example, Red Kangaroos occur primarily in the Australian interior in semiarid regions. Distribution of Kangaroos suggests an abiotic factor (precipitation) influences it, but perhaps populations also influenced indirectly by biotic factors such as competitors, predators, food availability and parasites. Ecologists have to consider multiple factors to explain patterns of abundance and distribution. Ecology has many subfields of study ranging from ecology of individual organisms to dynamics of landscapes Organismal Ecology Population Ecology Community Ecology Ecosystem Ecology Landscape Ecology We will explore these sequentially Distribution of species Biogeography: study of the broad patterns of distribution of organisms across the globe. Patterns strongly influenced by historical factors such as continental drift (see chapter 26) and barriers including mountain ranges and seas. For example, Australia populated by marsupial mammals (e.g. kangaroos, wombats, koalas) because placental mammals did not colonize it before it separated from other landmasses. Tapirs found only in southeast Asia and South America. Ancestral populations separated when land masses diverged. Role of dispersal in distribution Ability to cross barriers affects distribution. Thus, species of birds often more widely distributed than mammals. However, inability to reach an area not only factor that limits distribution. Ability to survive in new area is critical. To survive and thrive species must be able to cope with both biotic and abiotic factors. Biotic factors The presence of competitors or predators may limit an organisms ability to establish itself. For example, algae are eaten by sea urchins and limpets, which limits the ability of seaweeds to establish themselves on rocks Biotic factors Conversely, absence of predators and competitors has allowed many organisms introduced into new areas to increase so much they become pests. E.g. Japanese beetles (from Asia), zebra mussels and purple loosestrife from Europe) (Melaleuca (Eucalyptus trees from Australia) and many other invasive species have spread widely in the U.S. Abiotic factors The major factor affecting distribution of terrestrial organisms is climate, which incorporates temperature, sunlight, wind and precipitation. Abiotic factors Climate is determined by global factors such as inputs of solar energy and the movement of the earth through space. Study discussion of climate patterns pages 1088 and 1089 Climate Local factors such as the presence of mountains and large bodies of water also affect climate. Mountains force up moist air moving across them. As the air cools the water condenses and falls as rain. The result is that one side of the mountain range is wet and the other side is drier (and perhaps a desert [e.g. Mojave and Gobi Deserts.]) Climate Large bodies of water moderate climate. Land heats faster than water and warm air rises. Cooler air over water moves in and replaces the warm air. The warm air that was over land cools at high altitude and sinks over water. Results is steady flow of cool air over land. Terrestrial Biomes Biomes are major types of ecosystems that cover large areas of the earth and are classified by their dominant vegetation types. (an ecosystem is the community of organisms in an area and their physical environment) Each biome also is populated by a diverse array of animals, fungi and microorganisms adapted to that environment. Major terrestrial biomes include ‫غابة أستوائية‬ Tropical forest ‫صحراء‬ Desert ‫المراعي المعتدلة‬ Temperate Grassland Savanna ‫السافانا‬ Temperate broadleaf forest ‫غابات معتدلة عريضة األوراق‬ Coniferous forest (Taiga) )‫الغابة الصنوبرية (تايغا‬ Tundra ‫التندر‬ (see descriptions pages 1100-1104) Savannah Terrestrial biomes Terrestrial biomes often vertically stratified. Layers defined by different size plants (e.g. in forests there is an upper canopy of tall trees, low tree layer, shrub layer, ground layer of herbaceous plants, litter layer and root zone). Stratification provides multiple different habitats for animals which occupy specialized feeding niches. Convergent evolution Actual species in a biome differ from one area to another but they possess similar adaptations. This is convergent evolution (development of same evolutionary solutions to ecological problems) Convergent evolution For example vegetation in all deserts worldwide characterized by extensive root systems, long-term water storage capability, thick waxy coverings to reduce water loss, and extremely small (if any) leaves Biomes often maintained by disturbance. (Ecological disturbance) an event or force, of nonbiological or biological origin, that brings about mortality to organisms and changes in their spatial patterning in the ecosystems they inhabit. Wildfires are an essential factor in maintaining many biomes (e.g. grasslands, savannahs, some coniferous forests). Fire favors trees such as longleaf pine whose bark resists fire and grasses, which recover quickly after burning. Aquatic biomes Aquatic biomes less influenced by climate than terrestrial biomes Why? Aquatic biomes Water is more thermally stable. It takes a lot of heat to change the temperature of a body of water. Major aquatic biomes Lakes ‫بحيرات‬ Rivers ‫األنهار‬ Estuaries ‫مصبات األنهار‬ Intertidal zone ‫منطقة المد والجزر‬ Marine pelagic zone Coral reefs ‫منطقة السطح البحرية‬ ‫الشعاب المرجانية‬ Marine benthic zone (benthic zone is sea/lakefloor) See pages 1094-1097. Aquatic biomes often stratified by light and temperature. Light intensity decreases with depth. Upper (photic) zone supports photosynthesis. In ocean photic zone narrow but contains most organisms. Aphotic zone sparsely populated. Benthic zone (bottom) organisms often depend on rain of dead organic matter (detritus) from above. Thermal stratification of lakes Lake stratification is the tendency of lakes to form separate and distinct thermal layers during warm weather. In temperate areas lakes are thermally stratified in summer and winter. Water densest at 4ºC so water at this temperature sinks through colder or warmer water. Thus, in spring and fall all water in lake mixes which redistributes nutrients throughout the lake.