People and the Earth’s Ecosystems Course Pack 3 PDF

People and the Earth’s Ecosystems EGE 311 People and the Earth’s Ecosystem Welcome to People and the Earth’s Ecosystem 1|Page  People and the Earth’s Ecosystems Faculty Information: Getting help For...

People and the Earth’s Ecosystems EGE 311 People and the Earth’s Ecosystem Welcome to People and the Earth’s Ecosystem 1|Page  People and the Earth’s Ecosystems Faculty Information: Getting help For academic concerns (College/Adviser) For administrative concerns (College Dean) For UVE concerns (KMD) For health and wellness concerns (UAGC, HSD and OSAS) 2|Page  People and the Earth’s Ecosystems TABLE OF CONTENTS CONTENTS PAGE Cover page ………………………………… 1 Welcome Message ………………………………… 2 Table of Contents ………………………………… 3 USeP Vision, Mission and Goals ………………….. 4 USeP Graduate Attributes ………………………… 5 USeP Core Values ……………………………….... 5 Course Overview ………………………………… 6 Course Assessment ……………………………….. 7 Course Map ………………………………… 8 Module 1 Overview ………………………………… 10 The Lessons ………………………………… Module 2 Overview ……………………………….. 57 Lessons in Module 2………………………………. Module 2 Overview ……………………………….. 77 3|Page  People and the Earth’s Ecosystems UNIVERSITY OF SOUTHEASTERN PHILIPPINES VISION Premier Research University in the ASEAN. MISSION USeP shall produce world-class graduates and relevant research and extension through quality education and sustainable resource management. GOALS At the end of the plan period, the University of Southeastern Philippines (USeP) aims to achieve five comprehensive and primary goals: 1. Recognized ASEAN Research University 2. ASEAN Competitive Graduates and Professionals 3. Vibrant Research Community 4. Proactive Research-based Economic Empowering Extension Services 5. Capacity for Innovative Resource Generation 4|Page  People and the Earth’s Ecosystems INSTITUTIONAL GRADUATE ATTRIBUTES LEADERSHIP SKILLS Creates and inspires positive changes in the organization; exercises responsibility with integrity and accountability in the practice of one’s profession or vocation. CRITICAL AND ANALYTICAL THINKING SKILLS Demonstrates creativity, innovativeness, and intellectual curiosity in optimizing available resources to develop new knowledge, methods, processes, systems, and value-added technologies. SERVICE ORIENTED Demonstrates concern for others, practices professional ethics, honesty, and exemplifies socio-cultural, environmental concern, and sustainability. LIFELONG LEARNING Demonstrates enthusiasm and passion for continuous personal and professional development. PROFESSIONAL COMPETENCE Demonstrates proficiency and flexibility in the area of specialization and in conveying information in accordance with global standards. CORE VALUES OF THE UNIVERSITY UNITY STEWARDSHIP EXCELLENCE PROFESSIONALISM 5|Page  People and the Earth’s Ecosystems THE COURSE OVERVIEW (NOTE: all the necessary information below can be found in the syllabus. Just copy them and paste it here!) COURSE TITLE : General Ecology CREDIT :5 SEMESTER : 1st semester TIME FRAME : COURSE DESCRIPTION : This course deals on the basic principles and concepts of ecology emphasizing the natural ecosystems, communities, population, and individual species. It discusses the distribution of organisms in terms of their abundance, diversity indices, and frequency in different habitats. It illustrates the inter relationship of organisms, the limiting factors of each habitats, and the current trends, problems and specific cases of sustainable use of the environment and its resources. The course describes the current status of different ecosystems in a Philippine setting. COURSE OUTCOMES : CO1 Assess how the human population and activities affect terrestrial and aquatic resources. CO2 Analyze the relationship of the individual, society, economy, culture to the environment. CO3 Develop problem-solving skills to examine and propose solutions to different environmental problems. CO4 Integrate ecological principles with human activities towards sustainable development. 6|Page  People and the Earth’s Ecosystems COURSE ASSESSMENT Learning Evidence and Measurement Rubrics Course Learning Outcomes Description and other Details Evidence it represents LE1 Calculating Students will calculate their ecological footprint and determine how Your Carbon many planet Earth would be needed if everyone on Earth lived the same Footprint lifestyle as they do. By doing this, students will begin to understand the individual impacts they personally have on the environment. Students will then discuss ways that they can lower their ecological footprint. CO1, CO2, Measure the personal ecological footprint. CO3, Describe the factors that determine personal impact on the CO4 environment. Visit the following websites: https://www.footprintcalculator.org/ https://footprint.wwf.org.uk/#/ LE2 Environmental Students will create an educational video blog on the conservation and Wildlife status of a specific site in the Philippines with conservation value. Conservation Students will also learn to collaborate with appropriate experts, Efforts in the agencies or organizations in order to gather credible information for their Philippines topic. Students will develop an understanding on the status of the Philippine flora and fauna thus gaining knowledge on the responsible CO1, CO2, and sustainable use of natural resources through conservation. CO3, Explain why the national environmental policies are the cornerstone CO4 of Philippine environmental laws. Describe how environmental impact statements provide powerful protection of the environment. Visit: https://www.officialgazette.gov.ph/2001/07/30/republic-act-no- 9417/ Area to Assess Expected Satisfactory Acceptable 100 85 75 Timeliness -Submitted one week before -Submitted on scheduled -Submitted 1-5 days after the the scheduled deadline date scheduled deadline Content -Includes a clear and - Clear and comprehensive -Vague understanding of the comprehensive - Information is somewhat given topic hence information understanding on the organized conveyed is lacking conservation status of the - Some of the facts are -Ideas are not structured well chosen topic, species or site presented with supporting or in a confusing order -Information is well structured data -Supporting data is lacking and organized -Transfer of information and awareness to the audience is evident -Compelling presentation of factual data (graphs, tables etc.) to support/justify the conservation status in the country Citation - All borrowed information -Some of the information -Information on the video (images, media, text etc.) presented were not properly were not properly cited (>10 were properly cited cited (5) - Proper use of grammar and - Zero to minimal (2x) - 4-5 minute presentation spelling are rampant (>10 spelling/grammatical errors times) - 5-6 minute video - < 3 minute video presentation presentation Grading System Course Assessment Activity Description and other Details Outcomes it represents AA1 Examination (Midterm & A 50-item, multiple-choice test which covers all the Final) concepts and theories discussed in this course. The test CO1, CO2, items require the student to analyze situations and use CO3, their knowledge and understanding of the underlying CO4 principles, concepts, and theories of People and the Earth’s Ecosystem to solve the cases presented. AA2 Quizzes Objective-and-essay-type test to evaluate the CO1, CO2, knowledge/information of the students the underlying CO3, CO4 principles, concepts, and theories of Ecology. AA3 Oral Presentation A presentation given by a student with an assigned topic CO1, CO2, based on the underlying principles, concepts, and CO3, theories of Ecology integrated to human activities. CO4 AA4 Oral Recitation In-class and graded recitation or participation during or CO1, CO2, after the oral presentation/lecture/discussion. CO3, CO4 Assessment Grade Source (Score or Rubric Grade) Percentage of Final Grade Item AA1 Score (Examination (Midterm & Final)) 30% AA2 Score (Quizzes) 20% AA3 Rubric (Oral Presentation) 15% AA4 Score (Oral Recitation) 15% LE1 Calculating Your Carbon Footprint 10% LE2 Environmental and Wildlife Conservation Efforts in the Philippines 10% 8|Page People and the Earth’s Ecosystems 9|Page  People and the Earth’s Ecosystems Module 1 People and the Ecosystems Module Overview: The first part of this module introduces the major environmental problems that humans have created and considers ways to address these issues. The succeeding lessons tackle the attributes of a natural ecosystem, and the changes resulting from both natural and human activities. Module Outcomes: At the end of the lessons, students should be able to: Describe the three factors that are most important in determining human impact on the environment; Describe the basic principles and concepts of ecology; Examine the attributes of a natural ecosystem. 10 | P a g e  People and the Earth’s Ecosystems Lesson 1 Environmental Challenges We Face Learning Outcomes: Distinguish among highly developed, moderately developed, and less developed countries. Relate human population size to natural resources and resource consumption Distinguish between people overpopulation and consumption overpopulation. Describe the three factors that are most important in determining human impact on the environment. Define environmental sustainability. Identify human behaviors that threaten environmental sustainability. Time Frame: 1st week Introduction Welcome! This lesson talks about the effects of exponentially growing human population in the economy and the environment. The link between poverty and overpopulation is covered, its risks and the possible solutions through environmental sustainability are also tackled. Activity Instruction: Visit the links: https://www.worldometers.info/world-population/ and https://www.focus-economics.com/blog/the-poorest-countries-in-the-world , then answer the data sheet below Date and time of visit: ____________________________________________ The Current World Population: _____________________________________ Births per minute: _______________________________________________ Death per minute: _______________________________________________ Population growth today: _________________________________________ Population in the Philippines: _______________________________________ Current rank of the country: ________________________________________ Philippine Population change from 2010 to 2020: _______________________ Population density in 2019: ________________________________________ 11 | P a g e  People and the Earth’s Ecosystems Top 20 Countries with Land area 2019 rank as the poorest highest population country in the World 1. 2. 3. 4. 5. 6. 7. 8. 9. 10 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. Analysis Briefly answer the questions. You may use the back portion of this page. 1. Based on the activity, what is the economic status of the majority of the countries in the top 20? ______________________________________________________________ ______________________________________________________________ 2. What is the relationship between the Philippine population and its rank in the poorest country in the world? ______________________________________________________________ ______________________________________________________________ 3. Which countries in the top 20 have relatively low population based on its land area? ______________________________________________________________ ______________________________________________________________ 12 | P a g e  People and the Earth’s Ecosystems Abstraction Today, human race is the most powerful agent of environmental change on our planet. Our intellectual capacity has also made it possible for us to travel into space, enabling us to see the importance of our world in the solar system. However, we are overpowering the world with our expanding population; transforming forests, prairies, and deserts to meet our needs and desires; and consuming ever-increasing quantities of plentiful yet limited resources — rich topsoil, clean water, and breathable air. We are erasing thousands upon thousands of species as we kill or change their ecosystems. Evidence continues to mount that human-induced climate change puts the natural world at risk. Human Impacts on the Environment Earth’s central environmental problem, which links all others together, is that there are many people, and the number continues to grow. Human population in 2009: passed 6.8 billion individuals grown in a very brief span of time 1960 – 3 billion; 1975 – 4 billion; 1987 – 5 billion human population consume vast quantities of food and water; use a great deal of energy and raw materials; and produce much waste. On a global level, nearly one in four people lives in extreme poverty. Poverty – is a condition in which people are unable to meet their basic needs for food, clothing, shelter, education, or health. No one knows if Earth will sustain that many humans forever. Seeking ways to do this is one of the biggest tasks of our time. Among the challenges to be achieved is to feed a global population that is significantly greater than it is today without disrupting the biological ecosystems that sustain life on our planet. The quality of life available to our children and grandchildren will depend to a large extent on our ability to establish a sustainable agriculture system to feed the world's people. Rich and Poor Countries Countries are divided into rich (the “haves”) and poor (the “have-nots”). Rich countries are known as highly developed countries, examples are Norway, Switzerland, Qatar, USA, Canada and Japan. Highly developed countries – there are countries with complex industrialized bases, low rates of population growth, and high per person incomes. 13 | P a g e  People and the Earth’s Ecosystems Poor countries, in which about 82 percent of the world’s population live, fall into two subcategories: moderately developed and less developed. Moderately developed countries – are countries with medium levels of industrialization and per person incomes lower than those of highly developed countries. Example of countries are Turkey, South Africa, Thailand and Mexico. fewer opportunities for: o income o education o health care Less developed countries - are countries with low levels of the following: industrialization very high rates of population growth very high infant mortality rates; and very low per person incomes Examples are the Philippines, Bangladesh, Haiti and Laos Population, Resources and the Environment People of the highly developed countries consume many more resources per person than do citizens of developing countries. This high rate of resource use impacts the ecosystem at least as much as the population boom that is happening in other areas of the world. We may make two important generalizations about the relationship between population growth, natural resource use and environmental degradation. (1) the quantity of resources vital to an individual’s survival is small, but rapid population growth (often found in developing countries) tends 14 | P a g e  People and the Earth’s Ecosystems to overwhelm and deplete a country’s soils, forests, and other natural resources. (2) in highly developed nations, individual demands on natural resources are far greater than the requirements for mere survival. Rich countries deplete resources and degrade the global environment through increased consumption of nonessential items such as televisions, jet skis, and gadgets. It is important to differentiate between non-renewable and renewable natural resources when analyzing the impact of population on the climate. The two types of resources are: (1) nonrenewable resources - are natural resources that are present in limited supplies and are depleted as they are used. These include minerals and fossil fuels. Figure 1. Coal is an example of a nonrenewable resource - a fossil fuel. Image from https://www.nwf.org/Our- Work/Environmental-Threats/Climate-Change/Fossil-Fuels. (2) renewable resources – are resources that are replaced by natural processes and that can be used forever, provided they are not overexploited in the short term. Examples are trees, fishes and fresh water. Figure 2. Basic water cycle (hydrologic cycle). Image from https://www.weather.gov/jetstream/hydro. Rapid population growth can cause renewable resources to be overexploited. For example, o poor people must grow crops on land—such as mountain slopes or tropical rain forests—that is poorly suited for farming. The effects of population growth on natural resources are particularly critical in developing countries. o Economic growth of developing countries: 15 | P a g e  People and the Earth’s Ecosystems ▪ exploitation of their natural resources ▪ resources for export to highly developed countries Developing countries dilemma: o exploiting natural resources to provide for their expanding populations in the short term; or o conserving those resources for future generations. Poverty is tied to the effects of population pressures on natural resources and the environment. Population Size and Resource Consumption A country is overpopulated if the level of demand on its resource base results in damage to the environment. People overpopulation – is a situation in which there are too many people in a given geographic area. Consumption overpopulation – is a situation in which each individual in a population consumes too large a share of resources. Fact: Highly developed nations represent less than 20 percent of the world’s population, yet they consume significantly more than half of its resources. These countries also generate 75 percent of the world’s pollution and waste. Ecological footprint – is an amount of productive land, fresh water, and ocean required on a continuous basis to supply each person with food, wood, energy, water, housing, clothing, transportation, and waste disposal. Human impacts on the environment are difficult to assess. One way to estimate them is to use the three factors most important in determining environmental impact (I): (1) The number of people (P). (2) The affluence per person, which is a measure of the consumption, or amount of resources used per person (A). (3) The environmental effects (resources needed and wastes produced) of the technologies used to obtain and consume the resources (T). This method of assessment is usually referred to as the IPAT equation: 𝐼 =𝑃×𝐴×𝑇 The three factors in the IPAT equation are always changing in relation to each other. For example, consumption of a particular resource may increase, but technological advances may decrease the environmental impact of the increased consumption. Sustainability and the Environment Sustainability ensures that the ecosystem can work indefinitely without slipping behind the burden that human activities put on natural systems. 16 | P a g e  People and the Earth’s Ecosystems Environmental sustainability is the ability to meet humanity’s current needs without compromising the ability of future generations to meet their needs. This is based on the following ideas: (1) We must consider the effects of our actions on the health and well-being of the natural environment, including all organisms. (2) Earth’s resources are not present in unlimited supply. We must live within limits that let renewable resources such as fresh water regenerate for future needs. (3) We must recognize all the costs to the environment and to society of products we consume. (4) We must each share responsibility for environmental sustainability. Figure 3. Goals of sustainability. Image from Berg et al. (2011) Application Instruction: 1. Calculate your carbon/ecological footprint in one of these websites: a. https://www.footprintcalculator.org/ b. https://footprint.wwf.org.uk/#/ 2. Present the result of calculation in an essay that answers the following questions: a. What aspect in your daily life increases your footprint the most? b. What will be your action to reduce it? c. Why is knowing your carbon footprint important? d. As a young Filipino citizen, what can you do to achieve the goals of environmental sustainability? 3. Your essay must have a maximum of 250 words. Closure Congratulations for finishing this lesson! The next lesson is the basic concepts and principles of Ecology. 17 | P a g e  People and the Earth’s Ecosystems Lesson 2 How Ecosystem Works Learning Outcomes: Define ecology. Distinguish among the following ecological levels: population, community, ecosystem, landscape and the biosphere. Summarize how energy flows through a food web. Describe the carbon, hydrologic, nitrogen, sulfur, and phosphorus cycles. Describe the factors that contribute to an organism’s ecological niche. Describe interspecific relationships among organisms Discuss an example of a keystone species. Time Frame: 3 hours Introduction: Welcome to our second lesson in EGE 311! Time Frame: 2nd week (3 hrs lecture, 6 hrs laboratory) Activity Instruction: Go to your garden and list down its different components that work for it to survive and function as a system. Complete the table provided below. COMPONENT SOURCE 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 18 | P a g e  People and the Earth’s Ecosystems Analysis 2 Instruction: From the activity above. Group each component to energy source, nutrient source, plant community, animal community, community of decomposers, storage for nutrients and storage for organic materials. Use a separate paper for your table. Below is an example of how to make the table. GROUP FUNCTION Energy source 1. 2. Nutrient source 1. 2. 3. Plant community 1. 2. 3. Abstraction Definition Ecology is derived from the Greek word oikos (“household”) and logos (“study”). It literally means the study of household. This is the study of “life at home” with emphasis on “the totality or pattern of relations between organisms and their environment.” More scientific definition is the study of environmental house that includes all organisms in it and all the functional processes that make the house habitable. BASIC PRINCIPLES AND CONCEPTS OF ECOLOGY Levels-of-Organization Hierarchy Levels of organization is a hierarchical arrangement of order ranging from the ecosphere (or beyond) to cells (or beyond) illustrating how each level manifests emergent properties that are best explained at a particular level of organization. Hierarchy is the arrangement into a graded series, while a system consists of regularly interacting and interdependent components forming a unified whole. A biosystem is a system that constitutes living (biotic) and nonliving (abiotic) components; in the diagram, this is ranging from genetic systems to ecological systems. Ecology is largely concerned with the system levels beyond that of the organisms. 19 | P a g e  People and the Earth’s Ecosystems Population is a group of individuals of the same species occupying a common geographical area (for example flock of kalapati in People’s Park, students in a classroom, colony of hantik ant, and rice in a conventional farm treated with herbicide and insecticide. A community is composed of two or more populations of different species occupying the same geographical area (examples, herd of baka in a grass meadow, and normal flora “para ‘yes’ is the answer to the question: okay ka ba tiyan?”). Take note that populations and communities include only biotic factors. An ecosystem is community plus its abiotic factors (e.g. soil, rain, temperature and nutrients). The community and the non-living environment function together as an ecological system. For example, the coral reef in Talikud Island is an ecosystem with community of fishes, invertebrates, corals, algae, bacteria and planktons but these organisms are driven to live in this environment because their needs are met like the quality of sunlight for the zooxanthellae inside the tissue of coral polyps, pH, nutrients, salinity and temperature, also the water as their habitat. A landscape is defined as a heterogenous area composed of a cluster of interacting ecosystems that are repeated in a similar manner throughout. Example, is the Malagos Watershed—a watershed is a convenient landscape-level unit for large-scale study and management because it is usually having identifiable natural boundaries. Watershed as a stretch of land marked off by topographical features such as a ridge or mountain range, along which rain is caught and drained into a body of water like a river, lake, dam, irrigation system, or bay. Thus, a watershed encompasses the area that extends from the uplands to the downstream areas or lowlands, and the coast. Watersheds are also known as river basins or catchments. Biome is a term pertaining to a large regional or subcontinental system characterized by a major vegetation type or other identifying landscape aspect. Example is a tropical rainforest biome—the type of biome we have here in the Philippines, and the continental shelf ocean biome. While a region is not included in the diagram of ecological levels-of-organization hierarchy but it can be used to describe a large geological or political area that may contain more than one biome. Examples, the Southeast Asia that contains tropical rainforest and tropical moist deciduous forest biomes; and, the Middle East that contains desert, subtropical dry forest, temperate desert, subtropical steppe etc. Ecosphere is the largest and most nearly self-sufficient biological system which include all the living organisms of Earth interacting with the physical environment as a whole to maintain a self-adjusting, loosely controlled pulsing state. 20 | P a g e  People and the Earth’s Ecosystems Figure 4. This diagram shows that ecological hierarchy starts from populations to Ecosphere. ATTRIBUTES OF A NATURAL ECOSYSTEM Concept of ecosystem Biotic (living) organisms and abiotic (nonliving) environment are inseparably interrelated and interact with each other. Ecological system or ecosystem is any unit that includes biotic community (all organisms) in a given area interacting with the physical environment so that a flow of energy leads to clearly defines biotic structures and cycling of materials between living and nonliving components. The ecosystem is the first in the ecological hierarchy that is complete with all the components important for survival. Figure 5. Ecosystem model emphasizing the external environment. Ecosystems are open systems—that is, things are constantly entering and leaving. A graphic model of an ecosystem can consist of a box that we can label the system, which represent the area we are interested in, and two large circles that we can label input environment and output environment. Energy is a necessary input, which sun is the ultimate energy source for the ecosphere and directly supports most natural ecosystems in the biosphere. There are other energy sources that may be important for many ecosystems, e.g. wind, rain, water flow, or fossil fuel (major source for the modern city). 21 | P a g e  People and the Earth’s Ecosystems Energy also flows out of the system in the form of heat and in other transformed or processed forms, such as organic matter (food and waste products) and pollutants. Water, air and nutrients necessary for life, along with all kinds of other materials, constantly enter and leave the ecosystem; and organisms and their propagules (seed or spores) and other reproductive stages enter (immigrate) or leave (emigrate). Figure 6. Functional diagram of an ecosystem with emphasis on internal dynamics. S=storage; A=autotrophs; H=heterotrophs. In Figure 5, the system part of the ecosystem is shown as black box. However, we want to look inside it to see how it is organized internally and find out what happens to all those inputs (Figure 6). Energy flow is one-way, some of the incoming solar energy is transformed and upgraded in quality (that is, converted into organic matter, a higher-quality form of energy than sunlight) by the community, but most energy is degraded and passes through and out of the system as a low-quality heat energy (heat sink). Energy can be stored and “fed back,” or exported but it cannot be reused. In contrast with energy, materials, including nutrients necessary for life (such as C, N, P) and water, can be used over and over again. The community of autotrophs (A) and heterotrophs (H) are linked together with appropriate energy flows, nutrient cycles, and storages (S). Trophic structure of the ecosystem The two layers of ecosystem are (1) autotrophic stratum (upper) or the “green belt” of chlorophyll-containing plants in which the fixation of light energy, the utilization of simple organic substances, and the buildup of complex organic substances predominate; and (2) heterotrophic stratum (lower) or the “brown 22 | P a g e  People and the Earth’s Ecosystems belt” of soils and sediments, decaying matter , roots, etc. in which the utilization, rearrangement, and decomposition of complex materials predominate. Components constituting an ecosystem are: (1) organic substances that involved in material cycles (ex. C, N, CO2 and H2O); (2) organic compounds that link biotic and abiotic components (ex. Protein, carbohydrates, lipids and humic substances); (3) air, water and substrate environment, including the climate regime and other physical factors; (4) producers (autotrophic organisms) in which mostly green plants that can manufacture food from simple inorganic substances; (5) phagotrophs, heterotrophic organisms (animals), they ingest other organisms or particulate organic matter; and (6) saprotrophs, decomposers (mainly bacteria and fungi), these are heterotrophic organisms that obtain their energy by breaking down dead tissues or by absorbing dissolved organic matter (DOM) from plants and animals. Examples of Ecosystems A pond and an old field Plants, animals, and microorganisms not only live in the pond and the old field (or grassland), but they also modify the chemical nature of the water, soil, and air that compose the physical environment. Thus, a bottle of pond water or a scoopful of bottom mud or meadow soil is a mixture of living organisms—both plants and animals—and organic and inorganic compounds. Abiotic substance Abiotic substance includes inorganic and organic compounds, such as water, carbon dioxide, O2, Ca, N, S, and P salts, amino and humic acids, and others. A small portion of the vital nutrients is in solution and immediately available to organisms, but a much larger portion is held in reserve (“storage” S) in particulate matter as well as in the organism themselves. The rate of release of nutrients from the solids, the solar input, and changes in temperature, day length, and other climatic conditions are the most important processes that regulate the rate of function of the entire ecosystem on a daily basis. Producer Organism Producers in a pond are: (1) rooted or large floating plants (macrophytes) that generally growing in shallow water; and (2) minute floating plants, usually algae or green bacteria or protozoa (phytoplankton) that are distributed throughout the pond as 23 | P a g e  People and the Earth’s Ecosystems deep as light penetrates. In large deep ponds and lakes, phytoplankton is much more important than rooted vegetation in the production of basic food for the ecosystem. In the field or grassland, and in terrestrial communities in general, large, rooted plants dominate, but small photosynthetic organisms such as algae, mosses, and lichens also occur on soil, rocks, and stem of plants. Where these substrates as moist and exposed to light, these microproducers may contribute substantially to organic production. Figure 7. Phytoplanktons sampled in the seawater of Davao Gulf; a - Diploneis sp.; b - Oscillatoria sp.; c - Climacosphenia sp. Consumer organisms (1) Herbivores (primary macroconsumers) feed directly on living plants or plant parts, hereafter, they will also be termed as primary (first- order) consumers. The two types of microconsumers in the pond are zooplankton (animal plankton) and benthos (bottom forms). Herbivores in grassland and fields are the small, plant-feeding insects and other invertebrates, and the large, grazing rodents and hoofed mammals. (2) The secondary (second-order) consumers or carnivores, such as predaceous insects and game fish (nekton; free-swimming aquatic organisms) in the pond, and predatory insects, spiders, birds, and mammals that feed on the primary consumers or other secondary consumers (thus making them tertiary consumers). (3) Detritivores are another important consumer that live on the organic detritus from autotrophic layers above, and provides food for carnivores. 24 | P a g e  People and the Earth’s Ecosystems Figure 8. Zooplanktons collected from Davao Gulf seawater. Decomposer organisms The non-green bacteria, flagellates, and fungi are distributed throughout the ecosystem, but they are especially abundant in the mud-water interface of the pond and in the litter-soil junction of the grassland or old-field ecosystem. When temperature and moisture are favourable, the first stage of composition occur rapidly. Dead organisms do not retain their integrity for very long but are soon broken up by the combined action of detritus -feeding microorganisms and physical processes. Some of the nutrients are released for use. Figure 9. Decomposers in the forest litters in Mt. Hamiguitan, Davao Oriental. a - Boletus sp.; b – Pluteus sp. Fundamental concepts related to energy Energy is defined as the ability to do work. The behavior of energy is described by the following laws: The first law of thermodynamics, or the law of conservation of energy, states that the energy may be transformed from one form to another but is neither created nor destroyed. Light, for example, is a form of energy; it can be transformed into work, 25 | P a g e  People and the Earth’s Ecosystems heat, or potential energy of food, depending on the situation, but none of it is destroyed. The second law of thermodynamics, or the law of entropy, may be stated as: no process involving an energy transformation will spontaneously occur unless there is a degradation of energy from a concentrated form into a dispersed form. For example, heat in a hot object will spontaneously tend to become dispersed into the cooler surroundings. The second law may also be stated as follows: because some energy is always dispersed into unavailable heat energy, no spontaneous transformation of energy (sunlight, for example) into potential energy (protoplasm, for example) in over 100 percent efficient. Organisms, ecosystems, and the entire ecosphere possess the following essential thermodynamic characteristic: They can create and maintain a high state of internal order, or a condition of low entropy. Low amount of entropy is achieved by continually and efficiently dissipating energy of high utility (light or food, for example) into energy of low utility (heat, for example). Food resulting from the photosynthesis of green plants represents potential energy, which changes into other forms of energy when the food is used by organisms. Because one type of energy is always equivalent in quantity (but not in quality) to another type into which it is transformed, we can calculate one from the other. Energy that is “consumed” is not actually used up. Rather, it is converted from state of high-quality energy to a state of low-quality energy. Energy partitioning in food chains and food webs The transfer of food energy from its source in autotrophs through a series of organisms that consume and are consumed is termed the food chain. At each transfer, a proportion (often as high as 80 to 90 percent) of the potential energy is lost as heat. Therefore, the shorter the food chain—or the nearer the organism to the producer trophic level—the greater the energy available to that population. However, whereas the quantity of energy declines with each transfer, the quality or concentration of the energy that is transferred increases. Food chains are of two basic types: (1) the grazing food chain, which starting from a green plant base, goes to grazing herbivores and on to carnivores; and (2) the detritus food chain, which goes from nonliving organic matter to micro- organisms and then to detritivores and their predators. Food chains are not isolated sequences; they are interconnected. The interlocking pattern is often spoken of as the food web. Balance of nature hypothesis caused much discussion and controversy among ecologists. They argued that because plants by and large accumulate a lot of biomass, something must be inhibiting grazing. That something, they theorized, is predators. Accordingly, primary consumers are limited by secondary consumers, and primary producers are thus resource limited rather than grazer limited. Research has resulted in “bottom-up” versus “top-down” perspectives in the understanding of food chain dynamics. The bottom-up hypothesis holds that production is regulated by upstream factors such as 26 | P a g e  People and the Earth’s Ecosystems nutrient availability; the top-down hypothesis predicts that predators or grazers regulate productivity. Figure 10. Typical food web for terrestrial ecosystem. Biogeochemical Cycles The chemical elements, including all the essential elements of life, tend to circulate in the atmosphere in characteristic pathways from environment to organisms and back to the environment. These more or less circular pathways are known as biogeochemical cycles. Cycling of Nitrogen Nitrogen gas (N2) accounts for almost 80 per cent of the Earth's atmosphere, and nitrogen is also the resource that in many ecosystems limits primary production. Why should that be so? Since plants and animals cannot use such a source of nitrogen gas. For nitrogen to be usable to generate proteins, DNA, and other compounds of biological significance, it must first be transformed into a different chemical type. The method of transforming N 2 into nitrogen, which is naturally available is called nitrogen fixation. Many nitrogen-fixing species are free-living and others are symbiotic nitrogen-fixers, who need close interaction with a host for the cycle to be carried out. Most symbiotic relationships are very specific and have complex mechanisms which help to keep the symbiosis going. For example, root exudates from legume plants (like peas, peanut, soybeans) serve as a signal to some Rhizobium species, which are nitrogen-fixing bacteria. This signal draws the bacteria to the roots, and a very complex sequence of events then 27 | P a g e  People and the Earth’s Ecosystems induce the absorption of the bacteria into the root and activate the nitrogen fixation cycle of nodules forming at the roots. Some of these bacteria are aerobic, some are anaerobic; some are phototrophic, some are chemotrophic. While there is a great physiological and phylogenetic diversity among the species that perform nitrogen fixation, they all have a common enzyme complex called nitrogenase, which catalyzes reduction of N2 to ammonia (NH3). 1. Nitrification is the mechanism that transforms ammonia into nitrite and then nitrate, which is another important step in the global cycle of nitrogen. Most nitrification occurs aerobically, and is done by prokaryotes alone. There are two distinct nitrification steps which are performed by different types of microorganisms. Its first step is ammonia oxidation to nitrite that is performed by microbes known as ammonia oxidizers. Aerobic ammonia oxidizers use intermediate hydroxylamine to convert ammonia to nitrite, a method that involves two different enzymes, ammonia monooxygenase and hydroxylamine oxidoreductase 2. The second step in nitrification is the oxidation of nitrite (NO2-) to nitrate (NO3-). A completely different community of prokaryotes, known as nitrite-oxidizing bacteria, performs this step. Nitrospira, Nitrobacter, Nitrococcus, and Nitrospina are among the genera involved in nitrite oxidation. Figure 11. Biogeochemical cycling of nitrogen. Circulation of nitrogen between organisms and the environment. 28 | P a g e  People and the Earth’s Ecosystems New type of oxidation of ammonia taking place under anoxic conditions. Anammox (anaerobic ammonia oxidation) is performed by prokaryotes belonging to the Planctomycetes phylum of Bacteria. Anammox bacteria oxidize ammonia by using nitrite as the electron acceptor to produce gaseous nitrogen. 3. Denitrification is the mechanism that converts nitrate to nitrogen gas, thus eliminating bioavailable nitrogen and returning it to the atmosphere. Dinitrogen gas (N2) is the primary denitrification end result but there are other intermediate gaseous sources of nitrogen. 4. If an organism excretes waste or dies, the nitrogen in its tissues is in the form of organic nitrogen like amino acids and DNA. Various fungi and prokaryotes then decompose the tissue and release inorganic nitrogen back into the environment as ammonia in the process known as ammonification. The ammonia then becomes available for utilization by plants and other microorganisms for their growth. Cycling of Phosphorus Main supplies of phosphorus are present in surface water, rivers, lakes and seas, and in rocks and ocean sediments. The phosphorus cycle can be described as an 'open' cycle because of the general tendency of mineral phosphorus to be transported inexorably from the land to the oceans, mainly in rivers, but also to a lesser extent in groundwater, or through volcanic activity and atmospheric fallout, or through the abrasion of coastal land. Alternatively, the cycle may be referred to as a 'sedimentary cycle' since, essentially, phosphorus is absorbed into ocean sediments. Typical phosphorus atoms, which are released from rock through chemical weathering, can join and circulate within the terrestrial community for years, decades or centuries until they are transported via groundwater to a stream where they are part of a nutrient. The atom is transported to the ocean within a short period of joining the stream (weeks, months or years). This is taken up by species that live on the surface of the water, until they finally sink down into the oceans. Cycling of Sulfur Three natural biogeochemical processes release sulfur to the atmosphere: (i) the formation of the volatile compound dimethylsulfide (DMS) (by enzymatic breakdown of an abundant compound in phytoplankton dimethylsulfonioproprionate); (ii) anaerobic respiration by sulfate-reducing bacteria; and (iii) volcanic activity. Cycling of Carbon There is a chance that this carbon atom will become part of the skeleton of the plankton, or component of the bones of the larger animal that consumes it, and then part of the sedimentary rock when the organisms die and only the skeletons are left behind. Carbon, which is a part of rocks and fossil fuels such 29 | P a g e  People and the Earth’s Ecosystems as oil, coal and natural gas, can be kept away from the rest of the carbon cycle for a long time to come. Such long-term storage areas are called "sinks." Once fossil fuels are burned, carbon that was buried is sent to the air as carbon dioxide, a greenhouse gas. Carbon is a part of the seawater, the atmosphere, minerals in limestone and coal, soils, as well as all living organisms. On our complex world, carbon will pass from one of these domains to another as part of the carbon cycle. Carbon transfers from the atmosphere to the plants. Carbon is attached to oxygen in the air in a gas called carbon dioxide (CO2). Through the method of photosynthesis, carbon dioxide is drawn from the air to create food produced for plant production. Carbon transfers from plants to animals. In the food chain, carbon that is in plants moves to the animals that consume them. Animals that eat other animals get the carbon from their food. Carbon moves from plants and animals to soils. When plants and animals die, their bodies, wood and leaves decompose bringing the carbon into the soil. Some are buried and will become fossil fuels in millions and millions of years. Carbon moves from living things to the atmosphere. Each time you exhale, CO2 is released into the atmosphere. Animals and plants need to get rid of CO2 through respiration. Carbon moves from fossil fuels to the atmosphere when fuels are burned. When humans burn fossil fuels to power factories, power plants, cars and trucks, most of the carbon quickly enters the atmosphere as carbon dioxide gas. Carbon moves from fossil sources to the atmosphere as the fuel is burned. As humans burn fossil fuels to power factories, systems, cars and vehicles, most of the carbon soon released to the atmosphere as carbon dioxide gas. Carbon transfers from the atmosphere to the oceans. The oceans, and other bodies of water, absorb some carbon from the atmosphere. When the carbon molecules in the air touches the water surface, it dissolves into the water. The Hydrologic Cycle The hydrological cycle is simple to understand. The main source of water is the oceans; energy from the sun makes water evaporate into the atmosphere, winds distribute it over the surface of the Earth, and precipitation brings it down to earth in a form of rain, snow, or hailstorm where it may be stored temporarily in soils, lakes and icefields. Application Carbon dioxide is a greenhouse gas that naturally warms the atmosphere as part of the greenhouse effect. Unfortunately, the amount of CO 2 in the atmosphere has been increasing over the past hundred years. According to the 30 | P a g e  People and the Earth’s Ecosystems 2019 global report from National Oceanic and Atmospheric Administration (NOAA), the combined land and ocean temperature has increased at an average rate of 0.07°C, and the average rate of increase since 1981 (0.18°C) is more than twice as great. By 2020, models project that global surface temperature will be more than 0.5°C warmer than the 1986-2005 average, regardless of which carbon dioxide emissions pathway the world follows. 1. Explain how planting and growing more trees, and preserving the remaining forest cover in the planet could mitigate this warming trend in global temperature. 2. Do you think the lockdown in the past months due to Covid-19 pandemic affected the global biogeochemical cycles? Explain your answer. Factors that contribute to an organism’s ecological niche Niche While there are few environments on earth without life, no single species can tolerate the full range of earth’s environments. For each species, some environments are too warm, too cold, too saline, or unsuitable in other ways. We already learned that organisms take in energy at a limited rate. The environmental limits of a species are related to its niche. the niche summarizes the environmental factors that influence the growth, survival, and reproduction of a species. In other words, a species’ niche consists of all the factors necessary for its existence—approximately when, where, and how a species makes its living. The number of species in the population may be influenced by a range of abiotic factors. Sometimes one or more factors, known as limiting factors, are more important than other factors in regulating population growth. This ecological principle is called the 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 optimal range of tolerance. This principle describes one way in which population control—a scientific principle of sustainability is achieved. Success of an organisms, a group of organisms, or a whole biotic community depends on a complex of conditions. Any condition that approaches or exceeds the limits of tolerance is said to be a limiting condition or limiting factor. Limits of tolerance concept Not only may too little of something be a limiting factor but also too much of such factors as heat, light, and water. Thus, organisms have ecological minimum and maximum; the range in between represents the limit tolerance. The concept of the limiting effect of maximum as well as minimum constituents was incorporated into the Shelford law of tolerance. Some principle to the law of tolerance may be stated as follows: (1) organisms may have a wide range of tolerance for one factor and a narrow range for another; 31 | P a g e  People and the Earth’s Ecosystems (2) organisms with wide ranges of tolerance for limiting factors are likely to be most widely distributed; (3) when conditions are not optimal for a species with respect to one ecological factor, the limits of tolerance may be reduced for another ecological factors; (4) frequently, organisms in nature are not actually living at the optimum range of a particular physical factor; and (5) reproduction is usually a critical period when environmental factors are most likely to be limiting. The concept of limiting factors is valuable because it gives the ecologists an “entering wedge” into the study of complex ecosystems. On land, precipitation often is the limiting abiotic factor. Lack of water in a desert limits plant growth. Soil nutrients also can act as a limiting factor on land. Suppose a farmer plants corn in phosphorus-poor soil. Even if water, nitrogen, potassium, and other nutrients are at optimal levels, the corn will stop growing when it uses up the available phosphorus. Too much of an abiotic factor can also be limiting. For example, too much water or fertilizer can kill plants. Temperature can also be a limiting factor. Both high and low temperatures can limit the survival and population sizes of various terrestrial species, especially plants. Important limiting abiotic factors in aquatic life zones include temperature, sunlight, nutrient availability, and the low solubility of oxygen gas in water (dissolved oxygen content). Another such factor is salinity—the amounts of various inorganic minerals or salts dissolved in a given volume of water. Regulatory Factors Soil Biotic and abiotic components are specially intimate in soils, which by definitions consists of a weathered layer of Earth’s crust with living organisms intermingled with products of their decay. Because, for the most part, nutrients are regenerated and recycled during the decomposition in the soil before they become available for the primary producers, the soil can be considered a chief organizing center for land ecosystem. In general, the soil is the net result of the action of climate and organism, especially vegetation and microbes, on the parent material of the surface of the Earth. Fire Fire is major factor in shaping the history of vegetation in most of the terrestrial environment of the world. As climate pulses between wet and dry periods, so does fire in the environment. It is thus an extremely important limiting factor, if for no other reason than that the control of fire is far more feasible than the control of many other limiting factors. Temperature 32 | P a g e  People and the Earth’s Ecosystems Life as we know it can exist only within a tiny range of about 300 degrees Celcius—from about -200° to 100°C. Actually, most species and most activities are restricted to an even narrower band of temperatures. Some organisms, especially in a resting stage, can exist are very low temperatures, whereas a few organisms, chiefly bacteria and algae, can live and reproduce in hot springs where the temperature is close to the boiling point. Variability of temperature is extremely important ecologically. A temperature fluctuating between 10°C and 20°C and averaging 15°C does not necessarily have the same effect on organisms as a constant temperature of 15°C. Organisms that are normally subjected to variable temperatures in nature tend to be depressed, inhibited, or slowed down by constant temperatures. Light Light places organisms on the horns of dilemma: direct exposure of protoplasm to light causes death, yet sunlight is the ultimate source of energy, without which life could not exist. Light is not only a vital factor but a limiting one, at both the maximum and minimum levels. Ecologically, the quality, the intensity, and the duration of light are known to be important. Both animals and plants respond to different wavelengths of light. Color vision in animals sporadically occurs in different taxonomic groups, apparently being well developed in certain species of arthropods, fish, birds and mammals, but not in other species of the same group. The rate of photosynthesis varies somewhat with different wavelengths. In terrestrial ecosystems, the quality of sunlight does not vary enough to have an important differential effect on the rate of photosynthesis, but as light penetrates water, the red and blues are filtered out by attenuation, and the resultant greenish light is poorly absorbed by chlorophyll. Water Water, a physiological necessity for all life, is from the ecological viewpoint chiefly a limiting factor in land environments and in water environments where the amount can fluctuate greatly or where high salinity fosters water loss from organisms by osmosis. Rainfall, humidity, the evaporating power of the air, and the available supply of surface water are the principal factors measured. Rainfall is determined largely by geography and by the pattern of large air movements or weather systems. The distribution of rainfall over the year is an extremely important limiting factor for organisms. The following tabulation gives a rough approximation of the climax biotic communities (biomes) that may be expected with different annual amounts of rainfall evenly distributed in temperate latitudes: 0-25 cm per year—desert 25-75 cm per year—grassland, savanna 75-125 cm per year—dry forest >125 cm per year—wet forest 33 | P a g e  People and the Earth’s Ecosystems Humidity represents the amount of water vapor in the air. Absolute humidity is the actual amount of water in the air expressed as weight of water per unit of air. As the amount of water vapor that air can hold (at saturation) varies with temperature and pressure, relative humidity represents the percentage of water vapor actually present compared with the saturation density under existing temperature-pressure conditions. Because of the daily rhythm of humidity in nature (high at night, low during the day, for example), as well as vertical and horizontal differences, humidity, along with temperature and light, helps regulate the activities of organisms and limit their distribution. Types of interaction between two species In theory, populations of two species may interact in basic ways that correspond to combinations of neutral, positive and negative that can be symbolized as 0 for neutral, + for positive, and – for negative. 1. neutralism – neither population is affected by association with the other 2. competition, direct interference type – both populations actively inhibit each other 3. competition, resource use type – each population adversely affects the other indirectly in the struggle for resources in short supply 4. amensalism – one population is inhibited and others are not affected 5. commensalism – one population is benefited 6. parasitism; and 7. predation – one population adversely affects the other by direct attack but never the less depends on the other; 8. protocooperation (facultative cooperation) – both populations benefit by the association but their relations are not obligatory; and 9. mutualism – the growth and survival of both populations is benefited, and neither can survive under natural conditions without the other. Table 1. Analysis of two-species interactions based on Odum and Barrett (2005). General nature of Type of interaction Species 1 Species 2 interaction Neither population Neutralism 0 0 affects the other Direct inhibition of Competition, direct ̶ ̶ each species by interference type each other Indirect inhibition Competition, when common ̶ ̶ resource use type resource is in short supply 34 | P a g e  People and the Earth’s Ecosystems Population 1 Amensalism ̶ 0 inhibited, 2 not affected Population 1, the commensal, Commensalism + 0 benefits, while 2, the host, is not affected Population 1, the parasite, generally Parasitism + ̶ smaller than 2, the host Population 1, the Predation predator, generally (including + ̶ larger than 2, the herbivory) prey Interaction Protocooperation + + favorable to both but not obligatory Interaction Mutualism + + favorable to both and obligatory Note: 0 indicates no interaction; + indicates growth, survival, or other population attribute benefited; - indicates population growth or other attribute inhibited Application 1. A few years ago, laundry detergent makers were forced to reduce or eliminate phosphorus. Other cleaning agents (such as dishwasher detergents) still contain substantial amounts of phosphorus. What information would make you change your use of nitrogen, phosphorus, or other useful pollutants? 2. The first law of thermodynamics is sometimes summarized as “you can’t get something for nothing.” The second law is summarized as “you can’t even break even.” Explain what these phrases mean. Is it dangerous to oversimplify these important concepts? 35 | P a g e  People and the Earth’s Ecosystems Lesson 3 The Ecosystems Learning Outcomes: Define biome and discuss how biomes are related to climate. Briefly describe the nine major terrestrial biomes, giving attention to the climate, soil, and characteristic organisms of each. Summarize the important environmental factors that affect aquatic ecosystems. Describe the various aquatic ecosystems, giving attention to the environmental characteristics of each. Describe and distinguish among the main ocean life zones. Time Frame: 2 weeks Introduction This lesson talks about the major terrestrial biomes and aquatic ecosystems around the planet. Activity 1. What is a biome? 2. How do you distinguish between temperate rain forest and tropical rain forest? Between savanna and desert? 3. Which environmental factors shape flowing-water ecosystems? standing- water ecosystems? 4. How do the characteristics of a freshwater wetland differ from those of an estuary? How does a mangrove swamp differ from a salt marsh? 5. What are the four main life zones in the ocean, and how do they differ from one another? 36 | P a g e  People and the Earth’s Ecosystems Analysis What is happening in this picture? 1. This picture shows expensive homes built in the chaparral of the Santa Monica Mountains. Based on what you have learned in this lesson, what environmental problem might threaten these homes? 2. Sometimes people have removed the chaparral vegetation to prevent fires from damaging their homes. Where that has occurred, the roots no longer hold the soil in place. What could happen when the winter rains come? Abstraction BIOME  A large, relatively distinct terrestrial region with similar climate, soil, plants, and animals, regardless of where it occurs in the world.  Encompasses many interacting ecosystems  considered the next level of ecological organization above community, ecosystem, and landscape  temperature and precipitation, have a predominant effect on biome distribution. 37 | P a g e  People and the Earth’s Ecosystems Tundra Arctic tundra  Treeless biome in the far north that consists of boggy plains covered by lichens and mosses; it has harsh, cold winters and extremely short summers.  alpine tundra- similar ecosystem located in the higher elevations of mountains, above the tree line  growing season is short, the days are long  little precipitation, and most of the yearly 10 to 25 cm (4 to 10 in) of rain or snow falls during summer months  Tundra soil is nutrient poor and have little detritus  Permafrost beneath surface soil and impedes drainage  Limited precipitation, combined with low temperatures, flat topography (or surface features), and the layer of permafrost, produces a landscape of broad, shallow lakes and ponds, sluggish streams, and bog  recovers slowly from even small disturbances  Oil and natural gas exploration and military use have caused damage to tundra likely to persist for hundreds of years Flora Fauna Lemming ptarmigan 38 | P a g e  People and the Earth’s Ecosystems  supports relatively few species compared to other biomes but the species exist in great numbers  Dominant plants: Mosses, lichens, grasses, and grasslike sedges  Tundra plants seldom grow taller than 30 cm (12 in)  (year-round): lemmings, voles, weasels, arctic foxes, snowshoe hares, ptarmigan, snowy owls, and musk oxen Boreal Forest  region of coniferous forest (such as pine, spruce, and fir) in the Northern Hemisphere; located just south of the tundra. Also called taiga.  Winters in the boreal forest are extremely cold and severe, although not as harsh as those in the tundra.  receives little precipitation (50 cm (20 in) per year  soil is typically acidic and mineral poor, with a thick surface layer of partly decomposed pine and spruce needles.  permafrost deep under the surface  has numerous ponds and lakes dug by ice sheets during the last ice age.  world’s top source of industrial wood and wood fiber Flora  Dominating: Black and white spruces, balsam fir, eastern larch, and other conifers (cone-bearing evergreens)  Conifers have many drought-resistant adaptations, such as needle-like leaves whose minimal surface area prevents water loss by evaporation 39 | P a g e  People and the Earth’s Ecosystems Fauna caribou  Consists of some larger species such as caribou, which migrate from the tundra for winter; wolves; brown and black bears; and moose.  most boreal mammals are medium sized to small, including rodents, rabbits, and smaller predators such as lynx, sable, and mink.  Birds are abundant in the summer but migrate to warmer climates for winter.  Insects are plentiful, but few amphibians and eptiles occur except in the southern boreal forest. Temperate Rain Forest  A coniferous biome with cool weather, dense fog, and high precipitation.  Occurs on the northwest coast of North America, southeastern Australia and in southern South America  Annual precipitation is high—more than 127 cm (50 in)—and is augmented by condensation of water from dense coastal fogs  seasonal fl uctuation is narrow; winters are mild, and summers are cool.  Relatively nutrient-poor soil, though its organic content may be high.  Cool temperatures slow the activity of bacterial and fungal decomposers.  rich wood producer, supplying lumber and pulpwood Flora  Dominant: large evergreen trees such as western hemlock, Douglas fir, western red cedar, Sitka spruce, and western arborvitae  rich in epiphytes mainly mosses, club mosses, lichens, and ferns, all of which also carpet the ground 40 | P a g e  People and the Earth’s Ecosystems western hemlock Fauna Wood rat  Squirrels, wood rats, mule deer, elk, numerous bird species, and several species of amphibians and reptiles Temperate Deciduous Forest  A forest biome that occurs in temperate areas where annual precipitation ranges from about 75 cm to 126 cm (30 to 50 in).  Hot summers and cold winters  Soil consists of a topsoil rich in organic material and a deep, clay-rich lower layer.  among the first biomes converted to agricultural use Flora  Dominating in northeastern and mideastern United States: Broad- leaved hardwood trees (oak, hickory, and beech)  Trees form a dense canopy that overlies saplings and shrubs 41 | P a g e  People and the Earth’s Ecosystems Oak Fauna  originally contained a variety of large mammals, such as puma, wolves, and bison, which are now absent.  deer, bears, and many small mammals and birds Bison Tropical Rain forest  A lush, species-rich forest biome that occurs where the climate is warm and moist throughout the year.  are found in Central and South America, Africa, and Southeast Asia  Annual precipitation is typically between 200 and 450 cm (80 to 180 in).  commonly occurs in areas with ancient, highly weathered, mineral-poor soil.  Little organic matter accumulates in such soils; because temperatures are high year-round, bacteria, fungi, and detritus-feeding ants and termites decompose organic litter quite rapidly.  Roots quickly absorb nutrient minerals from the decomposing material. 42 | P a g e  People and the Earth’s Ecosystems  A fully developed tropical rain forest has at least three distinct stories, or layers, of vegetation (emergent story, canopy, understory) Flora Bromeliad  No single species dominates  trees are typically evergreen flowering plants.  Emergent layer: very tall trees, some 50 m (164 ft)  middle story, or canopy: trees 30 to 40 m (100 to 130 ft)  smaller plants in the sparse understory  communities of epiphytic plants such as ferns, mosses, orchids, and bromeliads Fauna Sloth  about 90% of tropical rainforest organisms are adapted to live in the canopy  abundant and varied insects, reptiles, and amphibians  Mammals: sloths and monkeys 43 | P a g e  People and the Earth’s Ecosystems Chaparral  A biome with mild, moist winters and hot, dry summers; vegetation is typically small-leaved evergreen shrubs and small trees.  soil is thin and often not very fertile.  Wildfires occur naturally and are particularly frequent in late summer and autumn Flora Scrub Oak  Dominant: dense thicket of evergreen shrubs— often short, drought- resistant pine or scrub oak trees that grow 1 to 3 m (3 to 10 ft) tall Fauna  Mule deer, wood rats, chipmunks, lizards, and many species of birds 44 | P a g e  People and the Earth’s Ecosystems Temperate Grassland  A grassland with hot summers, cold winters, and less rainfall than is found in the temperate deciduous forest biome.  Average annual precipitation ranges from 25 -75 cm (10 to 30 in)  Grassland soil has considerable organic material  occur in the United States in parts of Illinois, Iowa, Minnesota, Nebraska, Kansas, and other Midwestern states  Trees grow sparsely except near rivers and streams, but grasses taller than a person grow in great profusion in the deep, rich soil.  Periodic wildfires help to maintain grasses as the dominant vegetation in grasslands.  formerly supported large herds of grazing animals (bison and pronghorn elk)  Principal predators: wolves, coyotes  Smaller animals included prairie dogs and their predators (foxes, black- footed ferrets, and various birds of prey), grouse, reptiles such as snakes and lizards, and great numbers of insects.  are temperate grasslands that receive less precipitation than moist temperate grasslands but more precipitation than deserts.  occur in parts of Montana, Wyoming, South Dakota, and other midwestern states  Grasses that grow knee high or lower dominate  Plants grow less abundantly than in the moister grasslands, and bare soil is occasionally exposed. Fauna Pronghorn Elk 45 | P a g e  People and the Earth’s Ecosystems Savanna  A tropical grassland with widely scattered trees or clumps of trees.  found in areas of low rainfall or, more commonly, in areas of intense seasonal rainfall with prolonged dry periods.  Temperatures vary little throughout the year.  Precipitation is the overriding climate factor: Annual precipitation is 85 to 150 cm (34 to 60 in).  soil is somewhat low in essential nutrient minerals, in part because it is heavily leached during  rainy periods—that is, nutrient minerals filter out of the topsoil.  Occur in Africa, also in in South America, western India, and northern Australia.  converted into rangeland for cattle and other domesticated animals Flora Acacia  has wide expanses of grasses interrupted by occasional trees like the acacia, which bristles with thorns to provide protection against herbivores.  Both trees and grasses have fi re-adapted features, such as extensive underground root systems, that enable them to survive seasonal droughts as well as periodic fi res. Fauna  herbivores such as antelope, giraffe, elephants, wildebeest, and zebra  Large predators, such as lions and hyenas, kill and scavenge the herds. 46 | P a g e  People and the Earth’s Ecosystems Wildebeest Desert  A biome in which the lack of precipitation limits plant growth; deserts are found in both temperate and tropical regions.  consists of dry areas found in both temperate (cold deserts) and subtropical or tropical regions (warm deserts).  Low water vapor content of the desert atmosphere → daily temperature extremes of heat and cold  Desert environments vary greatly depending on the amount of precipitation they receive, which is generally less than 25 cm (10 in) per year.  desert soil is low in organic material but is often high in mineral content, particularly salts Flora Sagebrush  Plants in North American deserts include cacti, yuccas, Joshua trees, and sagebrush  Desert plants are adapted to conserve water and as a result tend to have few, small, or no leaves. 47 | P a g e  People and the Earth’s Ecosystems  Cactus leaves are modified into spines  Other desert plants shed their leaves for most of the year, growing only during the brief moist season. Fauna  typically small  desert-adapted insects and arachnids (such as tarantulas and scorpions)few desert-adapted amphibians (frogs and toads) and many reptiles, such as the desert tortoise, Gila monster, and Mojave rattlesnake.  Desert mammals in North America include rodents such as kangaroo rats, as well as mule deer and jackrabbits.  Birds of prey, especially owls, live on the rodents and jackrabbits, and even the scorpions.  During the driest months of the year, many desert animals tunnel underground, where they remain inactive. AQUATIC ECOSYSTEMS  The most fundamental division in aquatic ecology is probably between freshwater and saltwater environments.  Factors affecting distribution of organisms  Salinity- the concentration of dissolved salts (such as sodium chloride) in a body of water  dissolved oxygen  nutrient minerals 48 | P a g e  People and the Earth’s Ecosystems 3 main ecological categories of organisms 1. Plankton- usually small or microscopic organisms; tend to drift or swim feebly, so, for the most part, they are carried about at the mercy of currents and waves. 2. Nekton- larger, more strongly swimming organisms such as fishes, turtles, and whales. 3. Benthos- bottom-dwelling organisms that fix themselves to one spot (sponges and oysters), burrow into the sand (worms and clams), or simply walk about on the bottom (crawfish and aquatic insect larvae). Freshwater Ecosystems  include lakes and ponds (standingwater ecosystems), rivers and streams (flowing-water ecosystems), and marshes and swamps (freshwater wetlands).  about 2% of Earth’s surface  play an important role in the hydrologic cycle:  Large bodies of fresh water help moderate daily and seasonal temperature fluctuations on nearby land regions, and freshwater habitats provide homes for many species. Standing-water ecosystem  A body of fresh water surrounded by land and whose water does not flow; a lake or a pond.  Zonation is characteristic of standing-water ecosystems.  3 zones of a large lake: the littoral, limnetic, and profundal zones Zonation in a Large Lake 49 | P a g e  People and the Earth’s Ecosystems Lake: a standing-water ecosystem surrounded by land. Flowing-water ecosystems  are highly variable; surrounding environment changes greatly between a river’s source and its mouth  Certain parts of the stream’s course are shaded by forest, while other parts are exposed to direct sunlight.  Groundwater may well up through sediments on the bottom in one particular area, making the water temperature cooler in summer or warmer in winter than in adjacent parts of the stream or river  Organisms vary greatly from one stream to another, depending primarily on the strength of the current.  fast currents: some inhabitants have adaptations such as suckers, with which they attach themselves to rocks to prevent being swept away.  With flattened bodies to slip under or between rocks  fish that are streamlined and muscular enough to swim in the current. Freshwater wetlands  Lands that shallow fresh water covers for at least part of the year; wetlands have a characteristic soil and water- tolerant vegetation  include marshes, dominated by grasslike plants, and swamps, dominated by woody trees or shrubs  Wetland soils: waterlogged for variable periods and are therefore anaerobic; are rich in accumulated organic materials  provide excellent wildlife habitat for migratory waterfowl and other bird species, as well as for beaver, otters, muskrats, and game fi sh.  Provides ecosystem services 50 | P a g e  People and the Earth’s Ecosystems  threatened by pollution, development, agriculture, and dam construction  Ecosystem services- Important environmental benefits, such as clean air to breathe, clean water to drink, and fertile soil in which to grow crops, that the natural environment provides. Freshwater swamps -are inland areas covered by water and dominated by trees, such as baldcypress Brackish Ecosystems: Estuaries  A coastal body of water, partly surrounded by land, with access to the open ocean and a large supply of fresh water from a river.  Water levels rise and fall with the tides  Salinity fluctuates with tidal cycles, the time of year, and precipitation;also changes gradually within the estuary, from fresh water at the river entrance, to brackish (somewhat salty) water, to salty ocean water at the mouth of the estuary  organisms must have a high tolerance for changing conditions  usually feature salt marshes  shallow wetlands in which salt-tolerant grasses grow  perform many ecosystem services, including providing biological habitats, trapping sediment and pollution, supplying groundwater, and buffering storms by absorbing their energy, which prevents flood damage elsewhere.  Mangrove forests  the tropical equivalent of salt marshes  cover perhaps 70 % of tropical coastlines  provide valuable ecosystem services  Their interlacing roots are breeding grounds and nurseries for several commercially important fi shes and shellfi sh, such as mullet, spotted sea trout, crabs, and shrimp.  Mangrove branches are nesting sites for many species of birds, such as pelicans, herons, egrets, and roseate spoonbills.  Mangrove roots stabilize the submerged soil, thereby preventing coastal erosion and providing a barrier against the ocean during storms. Major Ocean Life Zones  intertidal zone  benthic (ocean floor) environment 51 | P a g e  People and the Earth’s Ecosystems  two provinces—neritic and oceanic—of the pelagic (ocean water) environment neritic province - part of the pelagic environment from the shore to where the water reaches a depth of 200 m (650 ft) -overlies the continental shelf. oceanic province - part of the pelagic environment where the water depth is greater than 200m, beyond the continental shelf. The Intertidal Zone: Transition Between Land and Ocean  area of shoreline between low and high tides  Rocky shores provide fi ne anchorage for seaweeds and marine animals  organisms are exposed to wave action when submerged during high tides and exposed to temperature changes and drying out when in contact with the air during low tides  Organisms and their adaptations:  mussels have tough, threadlike anchors secreted by a gland in the foot  barnacles secrete a tightly bonding glue that hardens underwater.  Some organisms hide in burrows or under rocks or crevices at low tide.  Some small crabs run about the splash line, following it up and down the beach. 52 | P a g e  People and the Earth’s Ecosystems The Benthic Environment  The ocean floor, which extends from the intertidal zone to the deep- ocean trenches.  consists of sediments (mainly sand and mud) where many bottom- dwelling animals, such as worms and clams, burrow  Bacteria are common at (1625 ft) below the ocean floor.  three zones in the deeper benthic (from shallowest to deepest): the bathyal, abyssal, and hadal zones.  The communities in the relatively shallow benthic zone that are particularly productive include coral reefs, sea grass beds, and kelp forests. Corals  -are small, soft-bodied animals similar to jellyfish and sea anemones.  -live in hard cups, or shells, of limestone (calcium carbonate) that they produce using the minerals dissolved in ocean water.  -forms from the accumulated layers of limestone. Coral reefs -are found in warm (usually greater than 21°C [70°F]), shallow seawater -The living portions of coral reefs grow in shallow waters where light penetrates. -The tiny coral animals require light for zooxanthellae (symbiotic algae) that live and photosynthesize in their tissues -coral animals capture food at night with stinging tentacles that paralyze plankton (small or microscopic organisms carried by currents and waves) and small animals that drift nearby. Coral reef ecosystems are the most diverse of all marine environments 53 | P a g e  People and the Earth’s Ecosystems They contain hundreds of species of fi shes and invertebrates, such as giant clams, snails, sea urchins, sea stars, sponges, flatworms, brittle stars, sea fans, shrimp, and spiny lobsters. provide habitat for many kinds of marine organisms and protect coastlines from shoreline erosion provide humans with seafood, pharmaceuticals, and recreation and tourism dollars. Sea grasses -are flowering plants adapted to complete submersion in salty ocean water -occur only in shallow water (to depths of 10 m, or 33 ft) where they receive enough light to photosynthesize -Extensive beds of sea grasses occur in quiet temperate, subtropical, and tropical waters. -Eelgrass is the most widely distributed sea grass along the coasts of North America -most common sea grasses in the Caribbean Sea are manatee grass and turtle grass -high primary productivity and are ecologically important: Their roots and rhizomes help stabilize sediments, reducing erosion, and they provide food and habitat for many marine organisms The Neritic Province: From the Shore to 200 Meters  The part of the pelagic environment that overlies the ocean floor from the shoreline to a depth of 200 m (650 ft).  Organisms are all floaters or swimmers  euphotic zone- upper level of the pelagic environment which extends from the surface to a maximum depth of 150 m (490 ft) in the clearest open ocean water. 54 | P a g e  People and the Earth’s Ecosystems  Large numbers of phytoplankton (microscopic algae) produce food by photosynthesis and are the base of food webs.  Zooplankton, including tiny crustaceans, jellyfish, comb jellies, and the larvae of barnacles, seaurchins, worms, and crabs, feed on phytoplankton.  Zooplankton are in turn consumed by plankton-eating nekton (any marine organism that sw