Ecology Flashcards
Comparison of Biotic and Abiotic Factors in Ecology
Biotic: Living components of the environment. Animals, plants, fungi, bacteria, algae. Interactions between organisms.
Abiotic: Non-living components of the environment. Air, water, soil, sunlight, temperature. Interactions between organisms and their physical surroundings.
Levels of Organization in an Ecosystem
Species: A group of organisms capable of interbreeding and producing fertile offspring.
Population: A group of the same species living in a specific area.
Community: Different populations interacting in a particular area.
Ecosystem: Interaction of communities with abiotic factors.
Biome: Large geographic areas with similar ecosystems.
Biosphere: The global ecological system integrating all living beings and their relationships.
Energy Flow in Ecology
Main Source: Sunlight.
Autotrophs (Producers):
Use sunlight (photosynthesis) or inorganic compounds (chemoautotrophs) to produce food.
Example: Plants, algae, and some bacteria.
Heterotrophs (Consumers):
Herbivores: Eat plants (primary consumers).
Carnivores: Eat herbivores or other carnivores.
Omnivores: Eat both plants and animals.
Decomposers:
Break down dead organic matter.
Example: Bacteria and fungi.
Ecological Pyramids
Producers: Form the base of the pyramid, creating energy.
Consumers: Depend on producers or other consumers for energy.
Decomposers: Break down waste and dead matter, recycling nutrients.
Food Chain vs. Food Web
Food Chain: A linear pathway showing energy flow in an ecosystem.
Food Web: A complex network of interconnected food chains.
Factors Affecting the Environment
Natural Factors:
Floods, earthquakes, and other natural disasters may destroy habitats and alter ecosystems.
Human Interference:
Industrial Effluents:
Contain heavy metals and toxic chemicals harmful to biodiversity.
Solution: Treatment plants.
Deforestation:
Cutting forests for wood and urban development destroys habitats, leading to species extinction.
Urban Spread:
Construction of towns, cities, and dams affects ecosystems and biodiversity.
Agriculture:
Overgrazing, excessive fertilizer use, and resource-depleting crops damage the environment.
Importance of a Balanced Environment
Organisms rely on their environment for food, shelter, and resources.
Disruptions in ecosystems, such as species extinction, can affect the entire food web.
A balanced ecosystem is essential for healthy living and biodiversity.
Ecosystems: An Overview
Definition
An ecosystem is a specific area where living organisms (biotic components) interact with each other and with their non-living (abiotic) surroundings.
Types of Ecosystems
Aquatic Ecosystems: Found in water (freshwater lakes, marine environments).
Terrestrial Ecosystems: Found on land (forests, grasslands, deserts, tundras).
Basic Components of an Ecosystem
Abiotic Factors
Non-living elements that influence ecosystems:
Air, Water, Soil: Provide essential resources.
Temperature, pH, Humidity: Define living conditions.
Light: Primary source of energy in most ecosystems.
Biotic Factors
Living organisms classified into:
Producers: Plants, algae (autotrophs) that produce food via photosynthesis or chemo-synthesis.
Consumers: Animals (heterotrophs) that depend on producers or other consumers for food.
Primary: Herbivores.
Secondary and Tertiary: Carnivores, omnivores.
Decomposers: Fungi and bacteria that break down dead organic matter, recycling nutrients.
Energy Flow and Trophic Levels
Producers: Capture sunlight to synthesize carbohydrates.
Consumers: Rely on producers and other consumers for energy.
Decomposers: Return nutrients to the soil for reuse by producers.
Ecological pyramids represent the energy flow and trophic levels:
Producers at the base.
Consumers in the middle.
Decomposers at the top.
Examples of Ecosystems
Aquatic Ecosystems
Freshwater Lakes:
Zones:
Littoral Zone: Shallow, diverse with plants, phytoplankton, fish.
Limnetic Zone: Deep, well-lit, supports photosynthesis.
Profundal Zone: Dark, nutrient-rich, dominated by decomposers.
Human Impact on Aquatic Ecosystems
Eutrophication: Excessive waste leads to algal blooms, depleting oxygen and harming life.
Terrestrial Ecosystems
Forest Ecosystems
Temperate Deciduous Forests: Found in moderate climates with rich soil.
Plants: Pinus, ferns.
Animals: Leopards, black bears.
Coniferous Forests: Harsh climates with snow cover, home to species like wolves and Marco Polo sheep.
Grasslands
Found in regions with 250-750 mm rainfall.
Plants: Grasses, herbs, mosses.
Animals: Amphibians, reptiles, and grazing mammals.
Deserts
Rainfall: 25-50 mm.
Adaptations: Water conservation in plants (succulents) and animals (kangaroo rats).
Tundras
Extremely cold, snowy regions.
Sparse vegetation with perennial flowers.
Animals: Snow owls, polar bears.
Major Ecosystems in Pakistan
Temperate Forests: Found in Shogran, Neelum Valley.
Coniferous Forests: Kaghan, Malam Jabba.
Grasslands: Gilgit, Waziristan.
Deserts: Thar, Cholistan.
Tundra: Karakoram and Hindukush mountains.
Human Interference in Ecosystems
Deforestation: Habitat destruction.
Pollution: Industrial and domestic waste causing eutrophication.
Overgrazing: Depletes grasslands.
Desertification: Conversion of fertile land into deserts.
