Readings in Sustainable Development
Topics related to ecosystems, environmental protection and other areas of sustainability.
READINGS IN SUSTAINABLE DEVELOPMENT READINGS IN SUSTAINABLE DEVELOPMENTt ALAN S. CAJES Readings in Sustainable Development ÂŠ 2011 Alan S. Cajes All rights reserved. Published 2011. Printed in the Philippines Printing or copying information exclusively for personal and noncommercial use with proper acknowledgment of the author is allowed. Users are restricted from reselling, redistributing, or creating derivative works for commercial purposes without the express, written consent of the author. Published by: Compendume Publishing & Consultancy Services Sampaloc, Manila ISBN 978-971-94507-1-9 Alan S. Cajes Page 2 Readings in Sustainable Development For Alvir who, when he was a boy, always asks his dad where water comes from. Alan S. Cajes Page 3 Readings in Sustainable Development CONTENTS Foreword Preface Ecosystems and Ecological Principles General State of the Philippine Ecosystems Introduction to Sustainable Development Philippine Agenda 21 Biological Capacity The Value of EIA Academe and the Environment Cleaning Up Manila Bay Introduction to Ecotourism Governance of the Electricity Sector: Selected Cases in Renewable Energy 5 7 11 28 38 65 72 78 88 113 123 139 Alan S. Cajes Page 4 Readings in Sustainable Development FOREWORD On July 30, 2003, I delivered a farewell message to the 9 batch of the Master in Public Management (MPM) Program of the Development Academy of the Philippines (DAP). I served as Acting Director of the MPM Program for about a year. On September 1, I went back to my mother unit at DAP â€“ the Environmental Management Office under the Center for Sustainable Human Development. In my message to the students, who come from various agencies of the government, I recalled to them what we briefly discussed in the Environmental Management (EM) Course that I handled as Associate Faculty. In the EM Course, I opened the class with a story on the creative emergence of Planet Earth under the big bang theory of the science of Cosmology. Lifting a leaf from an article written by Prof. Dr. Onofre D. Corpuz, founding president of DAP, I narrated the events as if they happened in one calendar year. Under the big bang theory, the first eleven months involved the formation of galaxies after the violent big bang, beginning with the separation of the gravitational force from the Infinite Singularity; followed by the formation of lumpy clouds of hydrogen and helium; followed by the formation of the galaxies; followed by the explosion of a sun called Tiamat in the Orion arms of the Milky Way that spewed forth heavy elements such as carbon, oxygen and nitrogen, and then finally the formation of the sun, Earth and the solar system. On the 12th month, December, the first microscopic forms of life emerged. On the last day of December, the first shell appeared. At the last minute of the last day of December, life emerged from the sea. During a tiny fraction of the th Alan S. Cajes Page 5 Readings in Sustainable Development last second of December 31, the first hominid ancestor of humans and apes and chimpanzees appeared. I recalled the story to emphasize that I was not taking myself seriously, as Corpuz would say. Human beings are just specks in the universe, but because of our inexplicable arrogance, we think of ourselves as the apex of creation. A good friend and a role model, Atty. Antonio Oposa Jr., a leading international expert on environmental laws, dismissed such claim as a figment of our imagination in his book, The Laws of Nature and Other Stories. The claim that we are the most intelligent of all the species, he argues, is a self-serving statement. It is inadmissible in court! Besides, biologist E. O. Wilson reminds us that if â€œall mankind were to disappear, the world would regenerate back to the rich state of equilibrium that existed ten thousand years ago. If insects were to vanish, the environment would collapse into chaos.â€? This book is part of my attempt to capture ideas and ideals that I have learned from others and I have applied in various projects or shared to various audiences in the form of lectures. The articles are presented as I have first articulated them. The goal is to capture and document those ideas and ideals as they unfold in a particular space and time. Some of the data and information may not be updated; hence, they need to be read within the context of the period when they emerged. I am sharing this humble output with the hope that the readers would recollect, as Plato would say, the knowledge that they have learned from the past. All errors are entirely my own. Alan S. Cajes Page 6 Readings in Sustainable Development PREFACE The idea of writing this book first came to me when some students from a state university called our office requesting for copies of articles that they could use as references in their school project. The students said that they visited our website, but could not download relevant materials that they could use. But it was former president Fidel V. Ramos who motivated me to document my professional experiences. In 2010, after delivering a lecture on Eco-Productivity as part of the topics of the EcoMismo Lecture Series conducted by the Ramos Peace and Development Foundation (RPDF), the former president told me that he would be glad to receive a written version of my brief presentation. This book is, in a way, a response to such prodding. It aims to provide processed information that the readers can use in their respective projects or undertakings. It covers related topics that I wrote or delivered as lectures to various audiences in the Philippines. Portions of the articles have also been shared to audiences outside the country through workshops and conferences that I have participated in. The first article, â€œEcosystems and Ecological Principles,â€? was written in 1996 as a part of the Course Kit for the Foundation Course on Environmental Management (FCEM). The Environmental Management Programme Office (EMPO) of the Development Academy of the Philippines (DAP), through the efforts of former DAP Vice President Josefa Rizalina M. Bautista, designed the FCEM to develop a critical mass of environmental management practitioners in the bureaucracy. The program had more than five hundred graduates, who included governors, mayors and local legislators. Feedbacks from my Alan S. Cajes Page 7 Readings in Sustainable Development colleagues at EMPO and from the various participants helped in improving the write up for succeeding FCEM runs. The second article, “State of the Philippine Ecosystems,” was a result of such feedbacks. The first draft, however, was actually written about a year before the first article came to be. It is an expanded version of an article that was used as a chapter of the Sourcebook on Community Resource Management, which was developed by the DAPEMPO for the Environmental Management Bureau (EMB) of the Department of Environment and Natural Resources (DENR). Dr. Minerva Chaloping-March, the project manager at that time, guided me in ensuring that I gave her the best possible technical support. “Introduction to Sustainable Development” is an abridged version of the Master’s thesis that I submitted and defended at the Graduate School of the Pontifical and Royal University of Santo Tomas in Manila. I am grateful to Prof. Dr. Florentino H. Hornedo for finding time to steer me in developing and writing the thesis. “Philippine Agenda 21” was first delivered as an introductory lecture on sustainable development. It was also used as a handout for the FCEM and the Course on Managing the EIA Process of DAP. “Biological Capacity” was originally titled as “Earth Day 2009: Sixto K. Roxas and Sustainable Development,” which was posted on my blog in 2009. The article is a rejoinder to the brilliant ideas that the noted Filipino economist shared to the DAP staff on the occasion of the celebration of Earth Day in 2009. I have learned a great deal from Dr. Roxas. Portions of this article have been used in other lectures that I have delivered, such as on disaster risk reduction and climate change adaptation. “The Value of EIA” is part of the handout for the Course on Managing the EIA Process. I have developed portions of this article for the reports of the project to strengthen Alan S. Cajes Page 8 Readings in Sustainable Development the system of reviewing environmental impact statements at the DENR-EMB. “Academe and the Environment” was first delivered as a lecture before selected students, parents, teachers, and non-academic personnel of De La Salle UniversityDasmariñas in Cavite on September 20, 2000. I received the invitation after facilitating the Solid Waste Management Summit of the Province of Cavite in the same year and while serving as technical expert for the Provincial Government in searching for ecological alternatives in waste management. “Cleaning Up Manila Bay” is based on the case filed by the Concerned Residents of Manila Bay against the concerned agencies of the national government for their failure to maintain the required water quality level of the bay. I was fortunate to witness Atty. Oposa argue before the Supreme Court en Banc on why the Court should require the concerned agencies to formulate and implement a plan to clean up Manila Bay. I thank Atty. Oposa for inviting us to listen to the oral arguments before the entire Supreme Court. “Introduction to Ecotourism” was used as an introductory article of the Manual for Ecotourism Planning and Development, which was prepared in 2005 by the DAP-EMPO for the DENR-Protected Areas and Wildlife Bureau (PAWB). I led a team that piloted the Manual in the Cities of Alaminos, Davao and Tagbilaran in 2006. Funding support came from the New Zealand Aid Programme (NZAID), the international aid and development programme of the New Zealand Government managed by the Ministry of Foreign Affairs and Trade. I thank the participants of the pilot runs of the Course on Ecotourism Planning and Development for their feedbacks and suggestions. “Governance of the Electricity Sector: Selected Cases in Renewable Energy” is based on the presentation I made before selected distinguished participants from the energy Alan S. Cajes Page 9 Readings in Sustainable Development sector at the Ateneo Blue Room of the Ateneo de Manila University. The paper was made possible with the support of Dean Antonio G.M. La Vina of the Ateneo School of Government and the World Resources Institute. I thank renewable energy expert Roberto Julian for the technical guidance and support. Many of the ideas that are found in this book are the products of discussions and interactions with ordinary citizens, experts and advocates of sustainable development. They are so many to mention, but I just would like to acknowledge the support and friendship of Lisa Antonio and Jo Bautista, my former bosses at DAPEMPO, and Dr. Marlito Cardenas, whose willingness to serve without counting the cost, continues to be a source of encouragement. Alan Salces Cajes Pasig City, Philippines Alan S. Cajes Page 10 Readings in Sustainable Development ECOSYSTEMS AND ECOLOGICAL PRINCIPLES Environment, Ecology and Ecosystems The term environment commonly refers to the immediate surroundings of an individual. In its broad sense, environment includes the following: • Bio-physical environment which includes flora, fauna, land, air and water bodies. • Socio-cultural environment or everything that relates to how people interact with each other. • Politico-economic environment or those that deal with how people organize themselves and exchange goods, services and ideas. Any activity that is undertaken in the environment results in environmental impacts. The activity may be formal, as in the case of various types of development projects. It could be informal, as in the case of daily chores of households or communities like the gathering of fire wood or grazing of animals. The impacts of human activities may be positive or negative. However, many of the environmental impacts are negative due to the failure in maintaining the structures and processes of nature. Ecology is defined as the study of the interrelationships and interdependencies of organisms with their environment. It is derived from the Greek word oikos, meaning "house" or "a place to live in". Etymologically, ecology is the study of organisms "at home". The primary concerns of ecology are: Alan S. Cajes Page 11 Readings in Sustainable Development • Population - a group of organisms with similar characteristics in a certain area at a given time • Community - refers to all the population occupying a given area • Ecosystem – the system of relationships of the species and their habitats. The interaction of the community and the non-living environment is an ecological system or ecosystem. This is also referred to as the life-support system. If the system is degraded, then the survival of the species is endangered. The ecosystem has the following components: • Inorganic substances (carbon, nitrogen, water) involved in material cycles • Organic compounds (proteins, carbohydrates) that link living and the non-living things • Climate regime (temperature and other physical factors) • Producers, self-nourishing organisms and green plants which can manufacture food from simple inorganic substances • Macro-consumers or eaters and heterotrophic organisms (animals) which consume other organisms or particulate organic matter • Micro-consumers, decomposers and heterotrophic organisms (chiefly bacteria and fungi) which break down the complex compounds of dead protoplasm, absorb some of the decomposition products and release inorganic nutrients that producers can use together with organic substances. The net results are energy sources or those that may inhibit or stimulate other living components of the ecosystems. The survival of the organisms in an ecosystem depends on nature's delicate balance of energy, food and other important factors. For example, without the green plants producing food through photosynthesis, there would be no oxygen to sustain human and animal life. Without the Alan S. Cajes Page 12 Readings in Sustainable Development action of water-dwelling decomposers on dead plants and animals, there would be no clean water in lakes and rivers. Without the biological processes that are going on in soil, there would be no food crops, coal or oil. It is clear that what helps maintain the delicate balance of the ecosystem is the constant interaction of both living and non-living components and the interaction of the living components among themselves. Now, the dependence of living species on each other comes in various forms: sometimes cyclical, but most often multi-linear. Animals, for example, depend on plants for food; plants depend on the action of soil bacteria for their nutrients; bacteria, in turn, live on the organic wastes such as livestock excretions to fertilize the soil. It may be said, then, that the life network of this planet is based on unity and diversity, collaboration and rivalry, formation and annihilation, elaborately and accurately organized, species by species, “with evolving relationships.” Concepts and Principles Governing Ecosystems Ecosystems may vary depending on the major types of living and non-living elements existing. They may be classified along two major types: • Natural ecosystems that include the upland or forest ecosystems, coastal and marine or aquatic ecosystems, wetlands, grasslands and freshwater ecosystems • Human-made ecosystems like the urban ecosystems that are self-sustaining. The natural and the human-made ecosystems are basically characterized by the continuity of life processes brought about by the presence of life-support systems that move around in cyclical patterns. The life-support systems also refer to nature's own system of endlessly recycling materials in the environment. This is how nature maintains it own balance or homeostasis. The natural ecosystems are briefly presented below. Alan S. Cajes Page 13 Readings in Sustainable Development Upland or Forest Ecosystem The Philippine forests are called tropical rainforests because of the country's tropical location and the amount of rainfall received (over 80 inches a year). Their principal characteristics are as follows: â€˘ Tall growing trees whose branches are often covered with other plants called epiphytes or plants that use other plants for support â€˘ Thick-stemmed woody vines â€˘ Large number of plant and animal species. The virgin forests or those forest areas that are still untouched by any significant woodcutting activities are characterized by the very dense tree canopy (the upper branches overlapping with each other) making the forest floor so dark and humid. The forests are considered as the "lungs of the earth". They enable the process of photosynthesis. They are also responsible for the continued supply of oxygen in the planet. The water cycle is also dependent on forests. Coastal and marine Ecosystem The marine environment is characterized by various features like largeness, depth, continuity, temperature, waves and tides, currents, salinity, pressures and light intensity. Together with the forest ecosystem, marine ecosystems are considered as the "bowels of the earth." The seas and oceans "recycle" a certain level or volume of pollutants that are eventually brought in by rivers and bays. This is done through the same processes of decomposition and cycling of nutrients found in the forests. The seas and oceans also act as "giant regulators" that help in moderating land climates and maintaining favorable concentrations of carbon dioxide and oxygen in the atmosphere. The seashores border the sea and the ocean. They are made up of smaller marine ecosystems, such as mangroves Alan S. Cajes Page 14 Readings in Sustainable Development and estuaries. Thousands of adaptive species not found in the open seas and oceans live in the seashores. A key responsibility of seashores is to trap erosion and wastes before these get into the sea. Seashores prevent large-scale marine pollution; hence, referred to as "free sewers" for coastal cities. In addition, they recycle waste matter into nutrients and often serve as breeding grounds for fish and other marine life. Freshwater Ecosystem It may be said that all forms of life are aquatic since water is both an essential and the most abundant substance in protoplasm. The freshwater ecosystem, which includes rivers, streams, lakes and bays, is the source of water for all forms of life -- as drinking water for humans and animals and as nourishment to plant life. Although it occupies a relatively small portion of the earth's surface, the freshwater ecosystems are important because they: â€˘ Are the most convenient and the cheapest source of water for domestic and industrial needs. â€˘ Are the "bottlenecks" in the hydrological cycle. â€˘ Provide the more convenient and cheapest waste disposal systems. What differentiates freshwater ecosystems from marine ecosystems is the absence of salinity or salt content. The intrusion of sea water destroys the freshwater ecosystem balance and certain freshwater species. Grasslands Grasslands are ecosystems characterized by single vegetation: grasses. They occur in areas where the rainfall is too low to support the forest life form, but is higher than that which results in desert life forms. The tropical grasslands, such as those in the Philippines, receive up to 60 inches of concentrated rain during the wet season Alan S. Cajes Page 15 Readings in Sustainable Development (deserts receive less than 10 inches (250 mm) of precipitation a year). In hot regions, prolonged dry seasons make the grasses dry and prone to fire. However, fire acts as a decomposer in the sense that it releases mineral nutrients from accumulated old litter that has become so dry. Bacteria and fungi are incapable of acting on very dry old litter. Thus, fires actually increase grassland productivity by speeding up the recycling, for as long as these do not happen for a very long period of time and exclude unnatural substances. Fires also maintain grass cover and favor grass in competition with thorny shrubs. From the human perspective, grasslands are extremely important because they provide natural pastures for grazing animals. In fact, the principal agricultural food plants have been developed by artificial selection from grasses. Many of the early civilizations are said to have evolved in grassland regions side by side with domesticated grazing animals. The human record in using grasslands as pastures is not as good. As a result, thousands of hectares of grasslands are converted into useless desert by overexploitation and the lack of concern. The human-made or domesticated ecosystems are presented below. Agricultural Ecosystems or Agro-ecosystems Agriculture is a process of using natural resources without jeopardizing the capacity of such resources for renewal. Specifically, it means cultivating land and rearing crops and livestock. Thus, agro-ecosystems refer to croplands that are developed and maintained with human inputs like chemical fertilizers, pesticides, irrigated water, heating systems, etc. as against natural grasslands or forests where the provisions of the life-sustaining cyclical processes are based on what is inherent in nature. Human survival is directly dependent on agroecosystems. It is important that people strive to Alan S. Cajes Page 16 Readings in Sustainable Development accommodate their natural processes in order to preserve the ecological balance. This means undertaking such approaches as bio-organic farming and multi-cropping to maintain species diversity and soil fertility. Fabricated Urban Ecosystems The urban ecosystem is derived from the concept that a city or an urban area is similar to a living organism. The city is seen as providing the means of life support for all people living within it. These life-support means include housing, employment, commercial opportunity, recreational and leisure facilities, health care and transport. The analogy implies that a city develops just like an organism: the city imports materials and energy in order to grow, as well as produces wastes that must be disposed of. If a city is poorly governed, then it can become unhealthy and ultimately die. Proper waste recycling, urban forestry, the use solar and wind energy, conversion of waste to energy, as biogas production, and such other return-to-nature are important in ensuring a sustainable future, especially for cities. These earth-friendly approaches will enable the growing industrialized civilizations to thrive. Structures and Functions in the Ecosystem There are different types of interrelationships and interaction between living organisms and their immediate physical, chemical and biological environment, as well as their organizations. This is due to the structural and functional characteristics of ecosystems. The main structural characteristics of an ecosystem include the food chain, food web and the food pyramid. The characteristics related to function mainly involve the biogeochemical substances. Structural Characteristics Alan S. Cajes Page 17 Readings in Sustainable Development Food Chain. The food chain is described as a structured feeding hierarchy whereby energy in the form of food is passed from an organism in a lower trophic level (or position occupied in the food chain) to one in a higher level. It occurs when plants (primary producers, first trophic level) are consumed by animals (higher trophic level), and these plant consumers (herbivores or plant eaters) are consumed by larger animals (carnivores or meat eaters). The energy is derived from the sun. The green plants convert the light energy into chemical energy through the process of photosynthesis. The plants use chemical energy to make sugar and oxygen from carbon dioxide and water. Each time an organism eats another in the food chain, energy is transferred. Such transfer of energy is one directional -- usually from plants to a series of animals eating each other. A human being can be a plant eater (herbivore) or a meat eater (carnivore) placed at the final level in the food chain. Food Web. Food web refers to the arrangement of who eats whom. Essentially, it is horizontal in nature. In a food web, an organism may feed on several members of the food web. A food web shows the interrelationship and interdependency of species, as well as the natural balance of habitats. Its complexity is critical in maintaining the diversity of species and stability of the ecological system. Food Pyramid. The food pyramid or life pyramid constitutes the overall structure of dependency among the living organisms in an ecosystem. At the lowest base of the pyramid are the producers of food sources, which are generally plants. However, one may go further down and say that at the lowest level of the pyramid is organic matter that serves as fertilizer of food sources. The producers are followed by the plant eaters or herbivores which feed directly on the producers. On the third level are the meat eaters or carnivores which feed on the herbivores. In the food pyramid, there are more producers than herbivores and similarly more herbivores than carnivores. Alan S. Cajes Page 18 Readings in Sustainable Development This means that a large supply of plant material is needed to feed a few insects and more insects are needed to feed a few animals. Any disruption or imbalance in any part of the food chain will result in food shortage since each part of the chain is dependent or connected to the other parts. Thus, sustainability of the food pyramid hinges on the continued availability and productivity of those at the lower levels. Food chain, food web and food pyramid are important factors to consider in monitoring the environmental impact of human activities. Any human activity external to the ecosystem would adversely affect the natural network of interactions among the organisms. Diversity. Diversity means the number of species (varieties or kinds) of plants and animals in a given community. Higher species diversity means longer food chains. Greater community implies stability. Species diversity is directly related to the stability of ecosystems. An ecosystem is stable if it has diverse species of plants and animals. A stable ecosystem has a greater capacity to withstand stresses or perturbations by human beings and nature. Conversely, an ecosystem that is already experiencing an environmental stress, or where the existence and quality of the species becomes threatened, will suffer reduction of individuals or reduced diversity. The rapid loss of forest cover, for instance, does not only mean the loss of trees, but also the loss of wildlife and life-support systems of tribal people who depend on trees for their survival. There are also losses of microorganisms that feed on decomposed leaves or fruits, as well as loss of plants that may provide medicinal value, new sources of nutrients and the like. As a result, the soil becomes directly exposed to weather elements like rain. Erosion is then more likely to occur. Distribution. The individuals of the same species in a certain area are distributed randomly, uniformly or clumply. Random distribution rarely occurs. It happens only when the environment is so uniform. In this situation, there Alan S. Cajes Page 19 Readings in Sustainable Development is no use for staying together to ensure survival. Such is the case of cactus in the desert. In areas where species are uniformly distributed, a severe competition among the individuals occurs. Sometimes such antagonism produces even spacing among animals or plants. Mice and chicken tend to be evenly distributed to be able to get nutrients and water evenly. Clumping or aggregation of individuals happen due to such factors as seasonal weather changes, reproductive practices, local habitat differences or threat from other species. The herding of grazing animals such as cows is an example of clumping. Any activity introduced in the environment should consider the nature of species distribution in an ecosystem. The disruption of the species natural distribution may eventually lead to their extinction. Density. Density refers to the number of individuals per unit area or volume. Examples are 500 pounds of fish per hectare and 300 trees per hectare. The lesser the environmental disturbance, the higher is the species density and the greater the capacity of the ecosystem to sustain itself. Dominance. Not all species in an ecosystem are equally dominant in determining the nature and function of the entire ecosystem. There are more dominant species playing a critical role in the maintenance of the ecosystem balance. The dominant species define certain ecological communities. They are the most abundant species; hence they influence the ecosystem. Many organisms rely on dominant species. Removing the abundant species could mean local extinctions. This is the case of huge dipterocarp trees or trees that have two-winged fruits. The removal of such trees through logging also results in the loss of wildlife that depends on them for survival. Succession. Over a period of time, the ecosystems develop through an orderly process involving changes in species structures and community processes. This results Alan S. Cajes Page 20 Readings in Sustainable Development from change of the physical environment by the community. Such process culminates in a stabilized ecosystem known as climax ecosystem in which maximum biomass or species density is maintained per unit of available energy flow. Examples are secondary forests that evolve into old growth trees in a process spanning many years. Ecological succession is directional; hence, predictable. For example, in an abandoned cropland formerly planted to corn and cotton, grassland develops. If the grass is left undisturbed for some time, the area will eventually be invaded by shrubs, and later on, by waves of trees of different species. The grasses tend to modify the physical environment, like soil and climate, and biota, making the conditions favorable for the invasion and growth of shrubs. The trees replace the shrubs until a balance or equilibrium between biotic (living factors) and abiotic (non-living factors) components in the area is reached. The last stage in the succession process is stable. It is no longer replaceable by other communities, unless disturbed by other external factors. Very few ecosystems, except those still unreached or untouched by humans, are able to undergo ecological succession due to human activities that do not promote the preservation or regeneration of species. An example is a denuded forest. Forests take many years to develop. When they are razed by fire or cleared up by logging, it will take many years to rehabilitate the damage. Efforts to replant logged over areas with monoculture species that grow fast do not necessarily restore the quality of the displaced forests. It is said that it is impossible to bring a degraded tropical forest back to its original condition. Characteristics Related to Functions Natural, biological, geological and chemical processes occur in different ecosystems. These natural cycles facilitate the self-regulating processes of ecosystems. They provide Alan S. Cajes Page 21 Readings in Sustainable Development fresh air and transform dead organic matter into a form that can be taken back into the metabolic system of plants. The circular paths that these substances follow are known as the "inorganic-organic cycles". The important cycles of materials found in ecosystems are described below. Water Cycle. Water on soil, plants and bodies of water evaporate into the atmosphere, collect into clouds and return as rain in the process called precipitation. More rains occur in areas where many plants grow, where there are lakes, rivers and oceans, and where the soil is moist. The excess precipitation may end up as ice or snow and return to the sea through streams and rivers. The cycle continues naturally unless a component is unable to perform its function. Rapid destruction of plants, as in the case of croplands turned into deserts and the denudation of large tracts of forest land disrupt the cycle in many places. Plants accumulate water from rainfall and then perspire it in the process called evapo-transpiration. The absence of plants prevents such processes from occurring and diminishes the availability of water to be recycled into the atmosphere. Consequently, even the rainfall patterns change. Carbon Cycle. Respiration and photosynthesis are the two important and basic life processes involved in this cycle. In respiration, compounds that have carbon are oxidized to from carbon dioxide. This gas is eventually released to the environment. In photosynthesis, the plants use water and the carbon dioxide from the environment. When the water molecules decompose so that hydrogen atoms can combine with carbon dioxide to form carbohydrates, oxygen is released to the atmosphere as byproduct. Another part of the carbon cycle is related to the organic compounds synthesized by plants and animals from the carbohydrates produced in photosynthesis. Plants produce protein and other protoplasm-forming substances. Planteating animals may synthesize other organic substances and Alan S. Cajes Page 22 Readings in Sustainable Development meat-eating animals may, in turn, resynthesize these organic substances into other compounds to support their life processes. The carbon contained in these compounds is retained in plant or animal tissues during the duration of their lives. Carbon is released back into the environment when plants and animals die and are decomposed by organisms. This explains the need for massive tree planting in urban areas where a lot of human, vehicular and industrial activities generate carbon dioxide. Nitrogen Cycle. The atmosphere comprises almost 80% nitrogen. The gaseous nitrogen, however, cannot be used directly by most organisms. Some micro-organisms like bacteria and blue-green algae convert gaseous nitrogen into more complex compounds, which are eventually used by plants and animals. Other nitrogen-fixing bacteria in the soil directly use the atmospheric nitrogen by making their own proteins. When these bacteria die, the nitrogen-containing compounds become available to plants and eventually to plant-eating animals. The decomposition of dead plants and animals leads to the production of ammonia. Ammonia is also given off by the decomposition of the waste products of organisms and by industries. It may dissolve in water and can then be easily taken up by the roots of plant or go to the soil and then converted by soil bacteria into nitrites of nitrates. Nitrites are not used by most plants, but nitrates are an important source of the nitrogen required for the formation of protein. Nitrates not absorbed by plants are converted by another group of bacteria to nitrogen gas, which goes into the atmosphere. A portion of the atmospheric nitrogen is converted by soil bacteria to ammonia, thereby repeating the cycle. Atmospheric nitrogen may be converted directly into nitrates by the physical action of lightning during thunderstorms. Phosphorous Cycle. This cycle does not involve the atmosphere. Phosphorous is an important and necessary constituent of protoplasm, which refers to the living Alan S. Cajes Page 23 Readings in Sustainable Development contents of a cell that is surrounded by a plasma membrane. It is produced by natural processes such as the gradual weathering and erosion of rocks or other deposits formed in the past geological ages. These natural processes release phosphates to the ecosystems, but much of the phosphates escapes into the sea, through the rivers, where marine algae eat them or where they are deposited in shallow and deep sediments. From there, the food chain in the sea passes these to marine birds and fish, and then brought to land by animals and man. Sea birds, in particular, play an important role in returning phosphorous to the cycle through the guano deposits. This transfer of phosphorous by birds from the sea to land is continuing, but no longer at the rate at which it occurred in the past. Basic Ecological Principles Nature works as a unitary whole, in an entirety of interactions that are beyond artificial divisions such as those imposed by people. Some principles drawn from environmental science underlie the meaning of sustainable development. All these principles are interrelated. All forms of life are important The tiniest plant and the tallest of trees, the unseen microorganism and the biggest of whales -- all have their distinct roles in the ecosystems. If one of these becomes extinct, then there is a breakdown in the food chain, in the food web, in the food pyramid, in the cycle of materials and therefore in the ecosystem. Everything is connected with everything else Both the living and non-living components of ecosystems depend on each other for survival. None of these components is superior to or controls the other. Due to Alan S. Cajes Page 24 Readings in Sustainable Development interrelatedness, factors affecting one part also affect the rest. The landslide that killed thousand of people in Ormoc City, for instance, was traced to logging in the uplands. Logging led to severe erosion and eventually caused flash floods. Nothing is for free Although the natural environment continuously recycles its nutrients, its resources are not infinite. There is a limit up to which an ecosystem can support the demands of a population on its resources. For example, the rapid increase of the country's population has exerted much pressure on the countryâ€™s fresh water resources. Nature knows best For generations, nature has taken care of itself. Humans must abide by nature's laws or suffer the consequences of its wrath. As part of the natural environment, humans have the duty and obligation to ensure that the fundamental ecological processes are not disrupted. Everything goes somewhere Materials in the environment are constantly reshaped or transformed, but nothing is created nor destroyed. This is among the most basic principles of nature. As nature performs its natural processes, organisms produce byproducts that become resources for others. But when humans tinker with the natural processes and misuse the natural resources, wastes and harmful materials are produced. Such by-products would, in turn, cause more degradation to ecosystems. Everything changes Alan S. Cajes Page 25 Readings in Sustainable Development The interaction of living and non-living things in an ecosystem is a constant process, which results in the transfer of energy from one being to another, growth and eventual decay of all matter -- all these in an endless cycle. The operation of natural laws assures that this process of change eventually results in the health and maintenance of the environment. Humans are the stewards of God's creation Humanity is realizing only now its true role with respect to the environment -- to manage it according to the laws which have enabled it to exist for many years. By abusing or wasting it, humans, in the end, will be the losers. As humans, however, learn to abide by the principles and processes of nature, they are able to benefit the most from it. The survival of the human race is directly proportional to the quality and productivity of the ecosystems. Alan S. Cajes Page 26 Readings in Sustainable Development Reference Materials Alcala, Angel C., E. Gomez, and H. T. Yap, “Philippine Coral Reefs: Status and Human Responses to Changes” in the Coastal Zone: Man’s Responses to Change. Switzerland: Harwood Academic Publishers, GmBH, Postrasse, 1988. Cajes, Alan S., “Nature as Source of Values” (Unpublished MS, October 1995). Department of Environment and Natural Resources - Environmental Management Bureau (DENR-EMB), Report on Philippine Environment and Development, 1991. _____________, The Philippine Environment in the Eighties, Quezon City, 1988. Environmental Management Programme Office (EMPO)Development Academy of the Philippines (DAP, Trainer’s Manual on Ecological Waste Management, 1995. (Unpublished). _____________, Sourcebook on Community Resource Management for Sustainable Development, 1995. (Unpublished). Jones, Gareth, Alan Robertson, Jean Forbes and Graham Hollier, The Harper Collins Dictionary of Environmental Science. New York: Harper Perennial, 1992. Lerma, Norma, “Ecology and Ethics” in Nature, Science and Value Readings. Manila: Santo Tomas University Press, 1988, pp. 49-75. Philippine Council for Agriculture, Forestry, and Natural Resources Research and Development (PCARRD), Watershed Management. PCARRD Technical Series Bulletin No. 72, Laguna, 1991. Ravera, Oscar (Ed.), Terrestrial and Aquatic Ecosystems Perturbation and Recovery. England: Ellis Hardwood, 1991. Alan S. Cajes Page 27 Readings in Sustainable Development GENERAL STATE OF THE PHILIPPINE ECOSYSTEMS The Philippine ecosystems covered in this paper include the inland water, coastal and marine resources, forest resources, agricultural resources and the urban ecosystem. Inland Water The inland water resources of the Philippines consist of rivers, lakes, streams, ponds and underground water reservoirs. These include over 421 rivers, 58 natural lakes and approximately 100,000 hectares of freshwater swamps. Most freshwater bodies in the Philippines are silted. Saltwater intrusion has affected about 480,000 hectares of freshwater areas. Out of the country's 421 river systems, 40 rivers are now considered biologically dead. All five rivers in the country' premier urban center, Metro Manila, namely Pasig, Paranaque-Zapote, Tullahan and San Juan rivers have mean concentration of dissolved oxygen (DO) well below the criteria for Class C rivers. The DO content ranges from 0.07 to 4.5 mg/L. The biochemical oxygen demand (BOD) has increased rendering the rivers fit only for navigation. Water pollution in Metro Manila and other urban areas is traced to domestic and industrial wastes. Other rivers of the country have also been polluted in varying degrees. River systems in mining areas have experienced pollution problems as early as the seventies. Siltation of the waterways appears to be the major problem. Unusually Alan S. Cajes Page 28 Readings in Sustainable Development high concentrations of mercury were observed in several water bodies in Mindanao. This can be attributed to the extensive use of mercury for recovering gold from ores. Siltation of rivers due to mine tailings from small- and largescale mining activities in the Baguio-Benguet area has reduced the water transport capacity of Agno, Bued and Amburayan Rivers. The Sipalay River in Negros Occidental, Lapis River in Zambales and Taft River in Samar also show similar problems. Heavy metal pollution in these river systems have posed serious health problems. The common metals present in the rivers are copper, lead, zinc, arsen