Ecology -BSCUV101 Abiotic factor 2, biotic factor, biogeochemical cycles, ecology functions, community ecology lecture notes KVB
Page 1: Factors Affecting Temperature
Influences on Temperature Distribution
Light Intensity: Affects temperature by influencing the energy available for heating.
Latitude: Geographic location impacts solar angle and climate patterns.
Altitude: Elevation affects temperature; higher altitudes typically result in cooler temperatures.
Ocean Currents: Movement of ocean water can redistribute heat and influence coastal temperatures.
Distance from Water Bodies: Proximity to large bodies of water can moderate temperatures in nearby regions.
Page 2: Importance of Temperature in Organism Distribution
Key Points
Single Most Important Influence: Temperature determines the physical state of water, crucial for life.
Life Range: Existence of life occurs within a range of -200 to 100°C; normal life persists between -10 to +50°C.
Extreme Tolerance:
Nematodes, rotifers, and tardigrades can withstand -272°C.
Chironomid larvae and some other Diptera thrive at ~55°C.
Algae and bacteria found in hot springs can survive at temperatures of 88°C or higher.
Example Species: Thermus aquaticus thrives above 90°C, found in Yellowstone geysers.
Page 3: Effects of Temperature on Plants and Animals
Cellular Effects
Lethal Effects: Extreme temperatures can damage cell proteins, with freezing forming ice crystals and heat leading to protein coagulation.
Metabolic Effects
Enzyme Regulation: Metabolic activities depend on enzymes influenced by temperature. Example: Liver arginase activity rises with temperature until a tipping point at 48°C where it retards.
Reproductive Effects
Gonad Maturation: Specific temperatures are required for maturation and gamete release, with notable impacts on egg production in grasshoppers at different temperatures.
Growth Effects
Growth rates in both plants and animals are temperature-dependent. Example: Adult trouts actively feed and grow only in waters warmer than 10°C.
Page 4: Further Temperature Influences on Organisms
Coloration
Temperature influences pigmentation; warmer climates often have darker pigments in animals.
Morphological Changes
Size and body proportions can vary; e.g., crows in colder climates tend to be larger due to more insulating feathers.
Behavioral Changes
Temperature impacts behavior; e.g., snakes use thermal cues to detect prey and exhibit clustering behavior in cold weather.
Distribution Constraints
Temperature limits species distribution; e.g., Atlantic lobster thrives in specific temperature ranges for breeding.
Precipitation Influence
Temperature variations influence atmospheric dynamics, affecting precipitation patterns which in turn affect ecosystem distributions.
Page 5: Climate and Humidity
Humidity Management by Organisms
Terrestrial organisms require specific water content; most water loss occurs via evaporation and transpiration.
Relative Humidity: % saturation of air affects water loss via diffusion, majorly through plant leaves or skin.
Page 6: Compensation for Water Loss
Organisms must balance water loss through uptake from the environment; plants absorb water via roots while animals may drink or take it through skin.
Xerophytes: Adaptations like reduced leaf surface area minimize water loss in arid environments.
Page 7: Interactions of Environmental Factors
Effects of Various Environmental Factors
Combined effects of temperature, humidity, and rainfall influence animal behavior and plant growth patterns.
Page 8: Characteristics of Wind
Wind Dynamics
Wind results from air mass movements caused by pressure differences and impacts temperatures and humidity levels.
Major influences on plant growth and animal behavior; wind facilitates dispersal of various organisms.
Page 9: The Role of Fire in Ecosystems
Fire Importance
Essential for certain ecosystems; conditions for fire include dry organic matter, weather, and a source of ignition.
Negative ecological impacts include temperature spikes, CO2 release, and erosion, while some species are adapted to environments affected by fire.
Page 10: Atmospheric Pressure Impacts
Effects on Life
Atmospheric pressure varies with altitude, affecting oxygen and carbon dioxide levels, crucial for respiration and photosynthesis.
Pressure impacts vary with altitude; humans and other animals may acclimatize or adapt to low-oxygen environments.
Page 11: Soil Composition Effects
Edaphic Factors
Soil properties like pH, water content, temperature, and atmospheric gases influence vegetation types and distributions.
Page 12: Physiographic and Topographic Factors
Geographic Considerations
Topographic factors impact climate and ecosystem characteristics through features like latitude, altitude, and mountain direction.
Variations in these factors lead to speciation and distinct vegetation zonation in environments ranging from mountains to plains.
Page 13: Biotic Interactions in Ecosystems
Positive Interactions
Mutualism: Beneficial for both species, e.g., pollination.
Commensalism: One species benefits, the other is unaffected (whales and barnacles).
Protocooperation: Beneficial but not obligatory cooperation.
Page 14: Negative Interactions in Ecosystems
Competitive Relationships
Exploitation: One species benefits at the expense of another.
Predation: Involves killing for food, affecting population dynamics.
Amensalism: One species inhibits another without self-harm.
Page 15: Ecosystem Functions
Ecological Roles
Ecosystems regulate processes, cycle nutrients, maintain trophic balance, and control mineral cycling and energy synthesis.
Page 16: Food Chain Dynamics
Overview
The food chain illustrates energy flow: from producers to consumers to apex predators.
Scavengers contribute to nutrient cycling by breaking down organic matter.
Page 17: Food Chain Structure
Basic Principles
Producers are at the chain's base, feeding only primary consumers, leading to secondary consumers.
Limited energy transfer efficiency influences food chain length.
Page 18: Complexity of Food Webs
Interconnectedness
The food web concept includes multiple feeding relationships, illustrating ecological complexity and interdependence.
Page 19: Ecological Pyramids
Representation of Energy Flow
Ecological pyramids depict relationships between organisms at different trophic levels in terms of biomass and energy.
Page 20: Types of Ecological Pyramids
Categories
Pyramid of Numbers: Counts organisms at each level.
Pyramid of Biomass: Indicates biomass distribution.
Pyramid of Energy: Shows energy transfer efficiency across levels.
Page 21: Food Web Composition
Relation of Food Webs to Ecosystems
Food webs encompass multiple food chains within an ecosystem, exhibiting complexity and multiple feeding options for organisms.
Page 22: Introduction to Biogeochemical Cycles
Essential Cycles
Important processes like the water, carbon, nitrogen, and phosphorus cycles impact ecosystem functioning and health.
Page 23: Community Ecology Insights
Community Dynamics
Studies interactions between coexisting organisms; species richness and diversity are key indicators of ecological health.
Page 24: Indicators of Ecological Balance
Species Diversity
High diversity indicates stable ecosystems; disruptions can lead to reduced diversity and imbalances.
Page 25: Keystone and Invasive Species
Community Structuring
Keystone species maintain ecological balance; invasive species disrupt local habitats.
Page 26: Concept of Niche
Niche Definition
Refers to a species' role in an ecosystem, including habitat interactions and resource utilization.
Page 27: Ecological Succession Process
Types of Succession
Primary Succession: Starts on bare rock, leading to soil formation and biodiversity.
Secondary Succession: Recovery after disturbances; faster due to pre-existing soil.
Page 28: Seral Communities Development
Development Stages
Intermediate stages towards climax communities; characterized by low diversity and food web complexity.
Page 29: Coral Ecosystem Succession
Coral Growth as Succession
Coral polyps contribute to ecosystem complexity and biodiversity through their growth patterns.