Environmental Science and Ecosystem Overview

Environment and Ecosystem

• Environment originated from the French word "Environner", meaning to encircle or surround.
• Environment (Protection) Act, 1986 defines environment as the sum of water, air, and land, and their interrelationships with human beings, other living organisms, and materials.
• Environment encompasses social, cultural, and physical conditions surrounding, affecting, and influencing survival, growth, and development of people, animals, and plants.

Environmental Science

• Environmental science is an interdisciplinary study of the environment, its biotic and abiotic components, and their relationships.
• It integrates physics, biology, and geography to study the environment and solve environmental problems.
• Environmental science examines how humans interact with the living and non-living components of their environment.

Environmental Engineering

• Environmental Engineering applies engineering principles to protect and enhance environmental quality, and to improve public health and welfare.

Environmental Studies/Education

• Environmental studies aim to educate people about preserving environmental quality.

Scope of Environmental Science

• Awareness and sensitivity towards environmental problems
• Active participation in environmental protection
• Developing skills to solve environmental issues
• Understanding the importance of conserving natural resources.
• Assessing environmental programs (considering social, economic, ecological, and aesthetic factors).
• Promoting cooperation (local, national, and international) for environmental prevention and solutions.
• Providing a clear picture of available resources and understanding environmental situations.
• Providing an understanding of the interconnectedness of nature and people.

Importance of Environmental Science

• Directly relates to quality of life
• Importance of sustainable development
• Knowledge of various environmental types and effects of hazards
• Understanding the effective role in protecting the environment and promoting changes in laws and enforcement systems
• Promoting respect and concern for the environment

Earth Life Support Systems

• The Earth system comprises the geosphere, atmosphere, hydrosphere, and biosphere.
• These components are interconnected and support life through energy flow (from the sun), nutrient cycling, and gravity.
• The major elements/spheres of the environment include: atmosphere, hydrosphere, lithosphere, and biosphere.

Atmosphere

• The atmosphere is a layer of air up to 1500 km surrounding Earth.
• It has distinct layers based on temperature variations (exosphere, thermosphere, mesosphere, stratosphere, troposphere).
• Oxygen is essential for living beings; carbon dioxide is vital for plants.
• Dust particles influence precipitation, and water vapor impacts plant and animal life; ozone protects from harmful UV rays.

Hydrosphere

• Hydrosphere encompasses all liquid and frozen surface waters (oceans, rivers, lakes, groundwater.)
• It plays a vital role in human life through drinking water, food, transport, and more.
• The water cycle (hydrological cycle) is an important process in the hydrosphere, influencing weather patterns and all life cycles.

Lithosphere

• The lithosphere is the solid part of the Earth, including the crust and uppermost mantle.
• It is significant due to tectonic plate activity and its role of supporting life.

Biosphere

• The biosphere is the zone where the lithosphere, hydrosphere, and atmosphere interact.
• It supports all forms of life.

Ecosystem

• Ecosystem is a natural unit composed of biotic and abiotic components.
• It includes interactions between living organisms (plants, animals, microorganisms) and nonliving components (soil, water, air, sunlight) which exchange materials to form a stable system
• Example, a pond ecosystem

Ecosystem Structure

• Abiotic Components:

  • Climatic factors: rain, light, wind, temperature
  • Edaphic factors: soil pH, soil minerals, soil water
  • Topographical factors: aspect, altitude

• Biotic Components:

  • Producers (autotrophs): plants, algae, that manufacture food
  • Consumers (heterotrophs): herbivores, carnivores, omnivores, that consume food
  • Decomposers (saprotrophs): bacteria and fungi that break down organic matter

Ecosystem Functions

• Regulates biological energy flow
• Controls nutrient cycling
• Influences biological regulation

Types of Ecosystem

• Terrestrial (forests, grasslands, deserts, tundra)
• Aquatic (freshwater, marine)

Freshwater Ecosystem

• Lentic: standing water (lakes, ponds, bogs)
• Lotic: flowing water (rivers, streams)

Marine Ecosystem

• Oceans, seas, estuaries, coral reefs, coastal regions
• Coral reefs are formed from skeletons of marine organisms.