Ecology and Environment

R N Bhargava, V Rajaram, Keith Olson, Lynn Tiede

• Publisher: CRC Press
• Year: 2019
• ISBN:
  9780429603341
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Ecology
• Index: Biological Sciences

The alarming rise in greenhouse gas and pollution level which has resulted in serious environmental and ecological harm is the biggest concern today. It has not only made the lives of mankind miserable but also threatens their very existence. Ecology and Environment has delved in depth on the subject and brings a broad perspective of the various issues. Following the curriculum of University Grants Commission, the book covers different types of ecosystem on the earth. It deals with the effective and sustainable use of natural resources which includes water, forest, mineral resources in the ground and productive land. The book explains the population trends in the world and India, and how it is impacting the environment. The role of public participation in promoting environmental sustainability is explored too.

Please note: This volume is Co-published with The Energy and Resources Institute Press, New Delhi. Taylor & Francis does not sell or distribute the Hardback in India, Pakistan, Nepal, Bhutan, Bangladesh and Sri Lanka

1

Multidisciplinary Nature of Environmental Studies

1.1 HUMANS AND THE ENVIRONMENT

‘Environment, being green, live green, go green, and sustainability’ are the catch phrases used in the present day. However, the concepts are not new. Societies of the past and many populations, who still live in rural settings, as is the case with 70% of India’s population, seem to intuitively have an understanding of the delicate dynamics of the environment and ecosystem. Those who live in poverty, again about 70% of India’s population, respect and have an innate sense of the importance of conserving natural resources and create smaller carbon footprints (the measure of a person’s total lifestyle demand on nature). Hence, while the discussion and greater awareness of the environment in the modern age by urban dwellers is relatively new; human dependency upon the environment and ecosystems, and the need to live in partnership with it, is not new at all.

The environment is defined as surroundings. This includes natural resources, such as air, water, and soil, all living organisms (animals, plants, people), and the built environment. The major ecosystems on the earth include soil, grasslands, savannas, shrublands, deserts, forests, tundra, freshwater, and marine.

Humans are one living organism that have interactions with all forms of ecosystems. Humans have inculcated the ability to alter organisms and interfere with the energy flows within an ecosystem. In this way an ecosystem is altered as a whole. Since the dawn of humanity, humans have been supported by their environment and at the same time altered it along the way. The earliest ancestors of homo sapiens lived approximately 4 million years ago and had the least destructive effect on the environment. They were hunters and gatherers and lived a subsistence lifestyle, utilizing what was available in nature for their survival. Overfishing, overhunting, and depletion of immediate resources prompted small nomadic groups to move to new areas where life could continue to be supported. The abandoned ecosystem had time to replenish.

When farming developed in the Tigris and Euphrates River Valley and in China around 8000 B.C., the humankind was at the early stage of initiating changes in the environment that would more greatly impact the ecosystem. To fulfil their needs, humans began to alter the environment by diverting water from rivers, adapting plants and animals through domestication, and settling in one place and building towns. As production of food increased, the size of the population also increased and specialized jobs developed. Now not everyone needed to be occupied with hunting and gathering, and growing food. This allowed urban and complex civilizations to develop that over time and with scientific discoveries blossomed into highly technological and industrialized world which we know today.

Never before has humanity used such ingenuity to utilize natural resources to create myriads of inventions, consumer products, and objects as they exist in our world today. In this process humans have depleted the natural resources utilized to make these things, disturbed ecosystems in pursuit of production of these goods, created pollution of water, soil, and air and produced greenhouse gases (GHGs) when manufacturing, transporting, and selling these items. A massive problem of waste disposal is also created when these items are not in demand anymore. Apart from this, modern advancements in technology has made it possible to support the ever-growing population. Of earth’s nearly 8 billion inhabitants, India alone supports over 1 billion people.

What are the consequences of this modern way of life on the environment and the earth’s ecosystems? Can nature continue to adapt to all these alterations induced by humans? Are there limits to how many people the environment can support? Natural resources such as water and trees are renewable, meaning they can be regenerated relatively quickly to meet human needs via normal ecological processes or agriculture. Others such as fossil fuels and minerals like gold and iron are non-renewable, that is, once they have been extracted from the earth they cannot be regenerated quickly. If even renewable resources are utilized or polluted at a rate that exceeds the carrying capacity of the environment, then they also cannot be regenerated. Evidence of this is quite readily available.

1.2 LOCAL TO GLOBAL SCOPE OF ENVIRONMENTAL ISSUES

Humans affect the environment at many levels. Climate change, acid rain, ozone layer depletion, overgrazing, overfishing, genetic engineering, species extinction, desertification, mining, and rising sea levels are just some of the effects of increased human impact on the environment. The ones most affected and of immediate concern are the homes and the local town or city. At this level, everyday actions and awareness can have immediate effects.

It is a well-known fact that if humans at individual level change day-to-day habits and actions that have adverse effect on the environment, changes can be witnessed at the global level. Steps taken at the individual level will include consumer products utilized, how one transports oneself, food eaten, energy and water consumed, and waste generated. At a cityor town level, this would include how well people design and regulate infrastructure that is environmentally friendly.

On a national level, one must look at all of these issues as well as impacts of urban versus rural living, how much nature is being conserved and preserved on the whole, and active attempts at plant and animal species preservation. The complete impact can be felt in a nation as one begins to see overcrowding, urban sprawl, loss of habitat, endangering of species, polluted waterways, waste management issues, and public health problems.

On a global level, we need to examine similar and even larger cumulative effects of human action. When one considers the environment on a national and global level, however, the cumulative effects of every country’s and the world’s citizens gets harder to calculate. Climate change and its effects on weather patterns, glacial melting, and extinction of species are the best examples. These larger cyclical changes are harder to understand and predict although scientists have made many observations and are tracking many irreversible changes. More industrialized nations like the U.S., Western Europe, and China are seen as larger contributors to climate change, while the impacts tend to affect the poor more detrimentally, irrespective of wherever they live.

1.3 DEFINITION, SCOPE, AND IMPORTANCE OF ENVIRONMENTAL STUDIES

While it is challenging to understand, untangle, and alter the adverse impact of human action on environment, it is imperative that the awareness of these environmental concerns from the local to the global level is transmitted to people with a sense of urgency. The ethics of living sustainably, that is, living in such a way that humans do not compromise the natural environment to the point of destruction while also preserving human life, culture, and economic vitality must be nurtured across the globe and at all levels of society.

A multidisciplinary approach that combines all of the sciences and social sciences is needed in order to deeply understand the origins of environmental issues, their complexity, and their impact. Environmental studies seek to do just that. All fields of natural science, that is, biology, botany, chemistry, geology, hydrology, physics, and zoology can shed light on the workings of the natural world and the impacts of human activity on this natural environment. All forms of social sciences and historical analysis, that is, anthropology, archaeology, civics, economics, geography, political science, and psychology can be useful in understanding how human impacts on the natural environment have varied over time and among cultures. These disciplines can also inform us of ways to proactively affect change at the individual, local, national, and global levels. These multifaceted disciplines and understandings they convey relationally are known as environmental studies.

The Precautionary Principle highlights the thoughtfulness that an environmental studies course which integrates both the natural and social science seeks to promote. Many environmental advocates utilize the Precautionary Principle adopted by UNESCO (the United Nations Environmental, Social, and Cultural Organization) in 2005 as a basis for thinking about environmental issues at the global level. This principle, in recognition of current serious environmental threats, calls on society to exercise caution and prudent restraint in environmental decision-making and the production and consumption of resources. The principle also calls for decision-makers to meet all humans needs (not just for those in the most industrialized and wealthy nations and classes of society) and to protect the rights of workers, local communities, and the general public, in a manner that causes the least environmental harm. This principle is a noble challenge and call to action for all.

Thus, the scope of environmental studies is broad and purposeful. It seeks to help humans live more consciously and aware of the natural resources used in their life and the impact of their actions individually and collectively on the environment. With a firm knowledge base, such educated citizenry can confront the magnitude of current environmental issues caused by humanity. As these issues grow, change, and are debated in public, environmental studies can foster solutions that will ensure the future of all life on earth.

Environmental studies seek to understand the relationship between humans and the natural environment. The importance of such studies cannot be underestimated in our environmentally challenged world today. Global warming due to greenhouse effect and rise in temperatures around the world are forcing a global debate on how the resulting climate change will impact populations around the world. Unless we reduce the release of carbon dioxide and other GHGs into the atmosphere, climate changes will impact more vulnerable populations and low-lying coastal communities will be submerged. This book discusses the current status of climate change and the mitigation measures that can be undertaken to minimize its adverse impact.

This book summarizes the major topics in environmental and ecosystem sustainability. Projects that can be completed in college and in the field are detailed to give the student hands-on familiarity with environmental issues. The importance of environmental issues in society is described at length with several examples from India. Two chapters are dedicated to importance of environmental education and public participation. A unique feature of this book is the wealth of International Case Studies where lack of environmental considerations has caused major adverse impacts in society.

2

Sustainable Ecosystems

2.1 INTRODUCTION

An ecosystem is defined as an interaction between living beings and the non-living environment in which they exist. Ecosystems exist on many scales: a large ecosystem contains many smaller ones. Also, one ecosystem may look quite different from another. The community of animals, plants, insects, and other organisms that have adapted to a high mountain range is different from the community of living beings that have adapted to a tropical forest, ocean, or desert. However, all ecosystems have a food web, nutrient cycles, and energy flow, and each part of the system is connected to another. Every ecosystem has a measurable carrying capacity: over-expansion or die-off of one species or disturbance of an important natural resource can affect the sustainability of the whole system. Pollution of water, air, and land and habitat destruction of animals can significantly affect the carrying capacity of an ecosystem. Climatic variations due to greenhouse gas emissions are harming the ecosystem. Governments around the world have been trying to minimize these variations by reducing the usage of fossil fuels and replacing them with renewable energy sources such as solar, wind, and bioenergy.

2.2 UNDERSTANDING ECOSYSTEMS

Every constituent of an ecosystem, whether living or non-living, has an important role to perform (Figure 2.1). For instance, forested slopes prevent erosion, trees produce oxygen and increase moisture in both air and soil, birds carry seeds to new locations, insects live on tree branches and eat away fungus, and microorganisms on the forest floor recycle leaf litter and other organic matter into nutrients that help the trees to grow.

Ecosystems are of different types: terrestrial—deserts, forests, grassland, tundra, mountains, islands, savannas; aquatic—oceans, lakes, ponds, rivers; and ecosystem where land and water meet—shores and swamps. Farms and cities are examples of human influenced ecosystems. Further, garbage dumps, parks, and sewers in cities form ecosystems with their own communities.

Figure 2.1 An ecosystem connects all other creatures in the community

An ecosystem is made of both living (biotic) and non-living (abiotic) components. The interactions between biotic and abiotic components affect an ecosystem’s equilibrium and survival. If one part of an ecosystem changes, it will affect all the other parts of the system. Ecosystems have feedback loops that make them more stable.

Bacteria, fungi, plants, insects, and animals, as well as waste products of these living things, such as fallen leaves and branches from plants and faeces, urine, and dead bodies of animals, form the biotic components of an ecosystem. The abiotic components include sunlight, water, nutrients such as carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulphur, and elements of climate such as rainfall, temperature, moisture, yearly cycle of weather patterns, salinity of water, and wind patterns. These factors have a great impact on the evolution, behaviour, and populations of living things in the ecosystem. All these factors help determine how the parts of the ecosystem will interact. Each member of the ecosystem community, from fly to tiger, occupies an important niche that helps to organize the system.

Sun is the main source of energy in an ecosystem. Whether in tropical or cold climates, summer is the most productive period because it is the season that receives the most sunlight. Longer summers or cooler summers owing to man-made climate changes affect the energy in the ecosystem and result in undesirable effects such as extinction of some species.

Ecosystems change over time in a process known as ecological succession. In this process, the dominant species of the ecosy...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Foreword
• Preface
• Table of Contents
• 1. Multidisciplinary Nature of Environmental Studies
• 2. Sustainable Ecosystems
• 3. Natural Resources
• 4. Biodiversity
• 5. Population and its Impact
• 6. Pollution, Sources, and Effects
• 7. Social Issues and Public Participation to Minimize Impacts of Development
• 8. Climate Change and its Impacts
• 9. Environmental Legislation and Enforcement
• 10. Education for Environmental Awareness
• 11. Projects and Activities
• 12. Indian and International Case Studies
• References
• Index
• About the Authors