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CBSE Notes Class 7 Geography Chapter 1 – Environment

CBSE Notes Class 7 Geography Chapter 1 – Environment

Natural Environment

The natural environment refers to the physical and biological elements that occur naturally on Earth without significant human intervention. It encompasses various components, including: Landforms: Natural features of the Earth's surface, such as mountains, hills, plateaus, plains, valleys, and deserts. These landforms are created through geological processes like tectonic activity, erosion, and weathering. Water Bodies: Natural water features, such as oceans, seas, rivers, lakes, ponds, streams, and waterfalls. They play a vital role in regulating the Earth's climate, supporting biodiversity, and providing habitats for aquatic organisms. Climate: The long-term weather patterns in a particular region, including temperature, precipitation, humidity, wind speed, and atmospheric conditions. Climate is influenced by factors like latitude, altitude, proximity to water bodies, and global air circulation patterns. Soil: The uppermost layer of the Earth's crust that supports plant growth. Soil is formed through the weathering of rocks and the accumulation of organic matter over time. It varies in composition, fertility, and texture across different regions. Natural Vegetation: The plant life that grows in a particular region without human intervention. It includes forests, grasslands, wetlands, tundra, and other types of ecosystems. Natural vegetation plays a crucial role in maintaining ecological balance, conserving soil, and providing habitats for various organisms. Biodiversity: The variety of living organisms found in a particular ecosystem or on Earth as a whole. It encompasses plants, animals, microorganisms, and their genetic diversity. Biodiversity is essential for ecosystem stability, pollination, nutrient cycling, and providing resources for human use.

What is ecosystem?

An ecosystem is a community of living organisms (plants, animals, and microorganisms) that interact with each other and their physical environment. It is a functional unit where both biotic (living) and abiotic (non-living) components are interconnected and influence each other's existence. Key features of an ecosystem include biotic components (producers), consumers (consumers), decomposers, and abiotic components (air, water, soil, sunlight, temperature, humidity, and minerals). Energy flows through an ecosystem in a unidirectional manner, and nutrients are recycled through various biogeochemical cycles. Interactions and relationships between organisms in an ecosystem can be categorized as predation, mutualism, competition, and symbiosis. Ecosystems can be of different types, such as forests, grasslands, deserts, aquatic ecosystems (fresh).

Human Environment

The human environment is the physical, social, cultural, and economic conditions created and influenced by human activities. It encompasses the built environment, human settlements, infrastructure, and the interactions of human beings with their surroundings. The built environment includes human-made structures and infrastructure such as buildings, roads, bridges, dams, cities, and towns. Human settlements are places where people live and engage in various activities. Urbanization is the process of the growth and expansion of cities and towns. Infrastructure refers to physical systems and facilities necessary for the functioning of a society. Social and Cultural Environment encompasses interactions, relationships, and social structures within a society. Economic Environment encompasses the production, distribution, and consumption of goods and services within a society. Environmental Impact includes pollution of air, water, and soil, deforestation, habitat destruction, climate change, and depletion of natural resources. Sustainable development aims to balance human needs with environmental conservation.

Biotic Components: These are the living organisms within an ecosystem. They can be categorized into three main groups:
  • Producers: Organisms, primarily plants, that produce food through photosynthesis using sunlight and convert it into energy.
  • Consumers: Organisms that consume other organisms for their energy requirements. They can be herbivores (consume plants), carnivores (consume other animals), or omnivores (consume both plants and animals). Decomposers: Organisms, such as bacteria and fungi, that break down dead organic matter and recycle nutrients back into the ecosystem.
  • Decomposers: Organisms, such as bacteria and fungi, that break down dead organic matter and recycle nutrients back into the ecosystem.

Abiotic Components: These are the non-living factors in an ecosystem that shape its physical environment. They include elements like air, water, soil, sunlight, temperature, humidity, and minerals. Abiotic factors determine the type of organisms that can survive and thrive in a particular ecosystem.

Lithosphere: It is the solid crust or the hard top layer of the earth.

Hydrosphere: It refers to the water bodies like rivers, lakes, seas, oceans, etc. on the earth.

Atmosphere: It is the thin layer of air that surrounds the earth.