ENVI-SCI-ECOSYSTEM

Water

  • Water is essential for all ecosystems.

Ecosystem Defined

  • Ecosystem: A biological community of interacting organisms and their physical environment.

  • Includes both living (plants, animals, organisms) and non-living (weather, earth, sun, soil, climate, atmosphere) components.

  • Dr. Riddhi Datta, Department of Botany, Dr. A.P.J. Abdul Kalam Govt. College.

Types of Ecosystems

  • Forest Ecosystem: Dominated by trees, supports rich biodiversity.

  • Grassland Ecosystem: Grass-dominated areas with seasonal rainfall.

  • Desert Ecosystem: Barren landscapes with scarce precipitation.

  • Aquatic Ecosystem: Involves water bodies, including freshwater and marine.

  • Dr. Riddhi Datta

Forest Ecosystem

Characteristics of Forests

  • Composed mainly of trees, shrubs, climbers, and ground cover.

  • Diverse ecosystems often found in various climates.

Components of a Forest Ecosystem

  • Abiotic Factors:

    • Variations based on location (mountains vs. valleys).

    • Influences include rainfall, temperature, latitude, altitude, soil type.

  • Biotic Factors:

    • Include diverse species of plants (angiosperms, gymnosperms) and animals (mammals, birds, reptiles, insects).

  • Example: Amazon Rainforest, rich interaction among organisms.

Structure of Forest Ecosystems

Producers

  • Plants: Primary photosynthetic producers supporting the ecosystem’s energy base.

Layers of the Forest

  1. Emergent Layer:

    • Tallest trees reaching up to 80 meters, mostly tropical.

  2. Canopy Layer:

    • Dense layer with closely spaced trees, rich in biodiversity.

  3. Understory Layer:

    • Receives less light; includes young canopy trees and shrubs.

  4. Shrub Layer:

    • Limited light; contains low shrubs.

  5. Ground Layer:

    • Composed of herbaceous plants, moss and decomposing matter.

Consumers in Forest Ecosystems

  • All animals are consumers, depending on other organisms for food.

Types of Consumers

  • Primary Consumers (Herbivores): E.g., Rabbits, Deer.

  • Secondary Consumers (Carnivores): E.g., Mongoose, Wildcats.

  • Tertiary Consumers (Top Carnivores): E.g., Tigers, Lions.

  • Omnivores: Consume both plants and animals.

Forest Ecosystem Animals

  • Tropical Rainforest Animals:

    • Birds: Cuckoo, Parrot, Eagles.

    • Mammals: Orangutans, Monkeys, Tigers.

    • Reptiles: Crocodiles, Anacondas.

  • Tropical Deciduous Forest Animals:

    • Contains diverse mammals, birds, reptiles, and amphibians.

  • Coniferous Forest Animals:

    • Mammals include deer, rabbits; various birds and reptiles present.

Decomposers in Forest Ecosystems

  • Decomposers break down dead organic matter, enriching the soil and supporting the nutrient cycle.

  • Mainly consist of bacteria and fungi.

Food Web in a Forest

  • Complex interaction among producers, consumers, and decomposers visualized as a food web.

Forest Types in India

  • Tropical Forests: Diverse species; includes moist and dry varieties.

  • Montane and Temperate Forests: Characterized by unique climate and species adaptations.

Desert Ecosystem

Characteristics

  • Deserts are arid regions receiving very little precipitation; host unique flora and fauna.

  • Including the cold deserts like in Ladakh and ecological systems like the Thar.

Components of a Desert Ecosystem

  • Abiotic Factors: Low organic matter, high temperatures, and extreme conditions.

  • Biotic Components:

    • Producers: Shrubs, cacti, and succulents adapted to retain water.

    • Consumers: Insects, reptiles (snakes, lizards), birds, and mammals.

    • Decomposers: Limited by low organic matter, include specific bacteria and fungi.

Grassland Ecosystem

Overview

  • Dominated by grasses; cover 24% of the Earth's surface, characterized by seasonal rainfall.

Components

  • Producers: Various species of grasses and some herbs.

  • Consumers: Herbivores (Cows, Deer), carnivores (Foxes), and decomposers.

Aquatic Ecosystem

Types

  • Freshwater Ecosystems: Ponds, lakes, and rivers with low salt concentrations.

  • Marine Ecosystems: Oceans and seas with high salinity, hosting adapted life forms.

Components

  • Abiotic Factors: Water chemistry, temperature, light, and nutrients.

  • Biotic Factors: Producers (macrophytes, phytoplankton) and consumers (varied organisms like fish, insects).

Lake and Pond Ecosystem

Structure

  • Comprised of zones: Littoral, Limnetic, Profundal, and Benthic.

  • Decomposers: Mostly bacteria and fungi that recycle nutrients.

River and Stream Ecosystems

  • Characterized by unidirectional flow and distinct biotic communities, subject to physical changes over time.

Ocean Ecosystem

Distinct Features

  • High salinity, specialized organisms adapted to marine environments.

Conclusion

  • Understanding these ecosystems and their components is crucial for conservation and ecological balance.