Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Ecology Organisms and Populations
Definition of Ecology
Levels of Organization in Ecology
Importance of Studying Ecology
Scope and Branches of Ecology
Components of an Ecosystem
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Definition of Ecology
Study of interactions between living organisms and their environment
Focuses on the relationships between individuals, populations, communities, and ecosystems
Interdisciplinary field that combines biology, geography, and environmental science
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Levels of Organization in Ecology
Organism
: Individual living entity
Population
: Group of individuals of the same species
Community
: All populations of different species in a particular area
Ecosystem
: Community along with its physical environment
Biosphere
: Sum total of all ecosystems on Earth
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Importance of Studying Ecology
Understanding the natural world and how organisms interact with their environment
Conservation and management of biodiversity
Predicting and mitigating the impacts of human activities on ecosystems
Identifying and solving environmental issues
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Scope and Branches of Ecology
Scope of Ecology
:
Studies interactions at individual, population, community, ecosystem, and biosphere levels
Integrates knowledge from various disciplines
Branches of Ecology
:
Population Ecology
Community Ecology
Ecosystem Ecology
Conservation Ecology
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Components of an Ecosystem
Biotic Factors
:
Living organisms (producers, consumers, decomposers)
Interactions between species (predation, competition, mutualism)
Abiotic Factors
:
Non-living components (temperature, sunlight, water availability, soil type)
Physical and chemical factors that influence organisms in an ecosystem
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Organisms and Populations
Definition of Species
Number of Species on Earth
Classification of Organisms
Factors Affecting Distribution and Abundance of Populations
Population Growth Models
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Definition of Species
Basic unit of classification in biology
Group of individuals that can interbreed and produce fertile offspring
Different species are reproductively isolated from each other
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Number of Species on Earth
Estimated number of species on Earth
: 8.7 million to 30 million
Only a small fraction of species have been identified and described
Numerous species remain undiscovered, especially in tropical regions
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Classification of Organisms
Taxonomy
: Science of classifying organisms into hierarchical groups
Kingdom, Phylum, Class, Order, Family, Genus, Species
Binomial Nomenclature
: Two-part naming system for species (Genus species)
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Factors Affecting Distribution and Abundance of Populations
Environmental Factors
:
Availability of resources (water, food, shelter)
Temperature, humidity, light, and other abiotic factors
Suitable habitat and ecological niches
Biotic Factors
:
Interactions with other species (predation, competition, mutualism)
Disease and parasites
Availability of mates
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Factors Affecting Distribution and Abundance of Populations (contd.)
Dispersal
:
Ability of organisms to move from one place to another
Migration patterns and seasonal movements
Adaptations
:
Specialized traits and behaviors that enhance survival and reproduction
Physiological, morphological, and behavioral adaptations
Human Activities
:
Habitat destruction and fragmentation
Pollution and climate change
Introductions of non-native species
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Population Growth Models
Exponential Growth
:
Idealized model of population growth under unlimited resources and space
Equation: dN/dt = rN
Example: Bacteria population with abundant nutrients
Logistic Growth
:
Realistic model that accounts for limited resources and environmental resistance
Equation: dN/dt = rN(1 - N/K)
Example: Wildlife population in a closed ecosystem
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Population Growth Models (contd.)
Carrying Capacity
:
Maximum number of individuals that an environment can support
Determines the stability of a population
Influenced by resource availability, competition, and limiting factors
Density-dependent Factors
:
Factors that affect population growth based on population size/density
Examples: Competition for resources, predation, disease
Density-independent Factors
:
Factors that affect population growth regardless of population size/density
Examples: Natural disasters, climate events
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Interactions Between Species
Predation
:
One species (predator) hunts, captures, and feeds on another species (prey)
Regulates prey populations and influences community dynamics
Example: Wolves preying on deer
Competition
:
Two or more individuals or species compete for limited resources
Can be interspecific or intraspecific
Example: Lions and hyenas competing for the same prey
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Interactions Between Species
Mutualism
:
Interaction in which both species benefit
Symbiotic relationship that enhances the fitness of both species
Example: Bees and flowers, where bees get nectar and flowers get pollination
Commensalism
:
Interaction in which one species benefits and the other is unaffected
Usually involves one species using the other for support or transportation
Example: Barnacles attaching to whales for transportation
Parasitism
:
Interaction in which one species (parasite) benefits while the other (host) is harmed
Parasites obtain nutrients from the host, potentially causing damage or disease
Example: Fleas feeding on dogs
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Energy Flow in Ecosystems
Food Chain
:
Linear sequence of organisms, showing the transfer of energy through consumption
Starts with a primary producer (autotroph) and ends with a top predator
Trophic Levels
:
Positions of organisms in a food chain
Producers are at the first trophic level, and consumers occupy subsequent levels
Food Web
:
Complex network of interconnected food chains
Represents the multiple feeding relationships within an ecosystem
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Energy Flow in Ecosystems (contd.)
Energy Flow
:
Energy is transferred from one trophic level to another
Energy decreases as it moves up the food chain due to heat loss and metabolic inefficiencies
Ecological Pyramids
:
Graphical representation of the energy flow and trophic structure in an ecosystem
Types: Pyramid of Numbers, Pyramid of Biomass, Pyramid of Energy
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Nutrient Cycling in Ecosystems
Biogeochemical Cycles
:
Process by which elements and compounds are exchanged and recycled within an ecosystem
Examples: Carbon, nitrogen, phosphorus cycles
Decomposers
:
Organisms that break down organic matter and release nutrients back into the soil or water
Examples: Bacteria, fungi, worms
Importance of Nutrient Cycling
:
Maintains the availability of essential elements for living organisms
Supports the growth of plants, which are the foundation of ecosystems
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Succession in Ecosystems
Ecological Succession
:
Gradual process of change in the species composition and structure of an ecosystem
Primary Succession: Colonization of barren or lifeless areas
Secondary Succession: Regeneration of ecosystems after disturbances
Pioneer Species
:
First organisms to colonize a previously unoccupied or disturbed area
Tolerant of harsh conditions and often modify the environment for other species
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Succession in Ecosystems (contd.)
Climax Community
:
Stable and self-sustaining community that persists over time
Dominant species are well-adapted to the prevailing environmental conditions
Importance of Succession
:
Helps restore ecosystems after disturbances
Enhances biodiversity and ecosystem resilience
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Diversity of Living Organisms
Importance of Diversity in Ecosystems
Definition of Biodiversity
Types of Biodiversity
: Genetic, Species, Ecosystem
Factors Influencing Biodiversity
Threats to Biodiversity
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Importance of Diversity in Ecosystems
Stability
: Diverse ecosystems are more resilient to disturbances and environmental changes
Productivity
: Biodiversity enhances the productivity of ecosystems, benefiting all species
Ecological Services
: Biodiversity provides various services, such as nutrient cycling and pollination
Medical and Economic Resources
: Many medicines and economic resources come from diverse ecosystems
Cultural and Aesthetic Value
: Biodiversity is important for cultural and recreational purposes
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Definition of Biodiversity
Biodiversity
: Variety of life forms on Earth, including genetic, species, and ecosystem diversity
It encompasses the richness, evenness, and distribution of organisms in different habitats
Biodiversity is measured through species richness, species evenness, and species diversity indices
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Types of Biodiversity
Genetic Diversity
:
Variation in the genetic makeup of individuals within a species
Important for adaptation and evolution
Example: Different breeds of dogs
Species Diversity
:
Variety of species present in an area
Includes species richness (number of species) and species evenness (relative abundance of species)
Example: Coral reefs with a large number of species
Ecosystem Diversity
:
Variety of habitats, communities, and ecological processes in an area
Includes different ecosystems like forests, grasslands, wetlands, etc.
Example: Amazon rainforest with its unique ecosystem
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Factors Influencing Biodiversity
Latitude
:
Higher diversity near the equator compared to polar regions due to more stable climates
Example: Tropical rainforests have high biodiversity
Habitat Complexity
:
More diverse habitats with a variety of niches support higher biodiversity
Example: Coral reefs with their complex structure
Climate
:
Stable climates with moderate temperatures and rainfall support higher biodiversity
Example: Tropical regions with consistent conditions
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Factors Influencing Biodiversity
Disturbances
:
Natural disturbances like fires and floods can create diverse habitats, promoting biodiversity
Example: Forests with periodic fires
Geographic Isolation
:
Isolated habitats can lead to the evolution of unique species, increasing biodiversity
Example: Islands with high endemism
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Threats to Biodiversity
Habitat Loss and Fragmentation
:
Clearing of forests, conversion of land for agriculture, urbanization
Fragmentation of habitats isolates populations, reducing genetic diversity
Example: Deforestation in the Amazon rainforest
Overexploitation and Hunting
:
Unsustainable hunting and fishing practices leading to the decline of species
Example: Overfishing of certain fish species
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Threats to Biodiversity
Pollution and Climate Change
:
Pollution from industries and agriculture affects ecosystems and species
Climate change alters habitats, resulting in the loss of species
Example: Global warming impacting coral reefs
Invasive Species
:
Introduction of non-native species that disrupt native ecosystems and outcompete native species
Example: Asian carp in North American waterways
Disease
:
Outbreaks of diseases can decimate populations and threaten species
Example: White-nose syndrome affecting bat populations
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Conservation of Biodiversity
Conservation Strategies
:
Protected Areas: Establishing national parks, wildlife sanctuaries, and marine protected areas
Habitat Restoration: Restoring degraded habitats to promote biodiversity
Conservation Programs: Initiatives to protect vulnerable species and their habitats
Sustainable Resource Use: Managing resources in a way that avoids depletion and supports biodiversity
International Efforts
:
Conventions and Agreements: Examples include the Convention on Biological Diversity (CBD)
Biodiversity Hotspots: Identifying and conserving areas with high levels of biodiversity and endemism
Individual Actions
:
Promoting awareness and sustainable behaviors, supporting local conservation efforts
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Case Study Conservation of Tigers
Importance of Tigers
:
Keystone species in their ecosystems, maintaining prey populations and habitat structure
Symbolic species, representing conservation challenges and efforts
Threats to Tigers
:
Habitat loss, poaching, illegal wildlife trade, human-wildlife conflict
Conservation Measures
:
Protecting tiger habitats, establishing protected areas and corridors
Anti-poaching efforts and strict enforcement of wildlife laws
Community involvement and educating local communities about tiger conservation
Successes and Challenges
:
Increase in tiger populations in some areas
Continued efforts needed to address illegal wildlife trade and habitat loss
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Case Study Coral Reefs
Importance of Coral Reefs
:
High biodiversity and productivity, supporting numerous species
Protection of coastlines, providing habitat and nursery areas
Threats to Coral Reefs
:
Climate change, ocean acidification, coral bleaching, pollution, overfishing
Conservation Measures
:
Marine protected areas and coral reef management
Reducing pollution and addressing climate change
Promoting sustainable fishing practices and reducing destructive fishing methods
Successes and Challenges
:
Some coral reef areas showing signs of recovery and resilience
Ongoing degradation and the need for global action to protect coral reefs
Ecology Organisms And Populations Diversity Of Living Organisms Number Of Species On Earth
Summary and Key Points
Ecology studies the interactions between organisms and their environment.
Levels of organization in ecology
: organism, population, community, ecosystem, biosphere.
Biodiversity refers to the variety of life forms and is essential for ecosystem stability and productivity.
Types of biodiversity
: genetic, species, and ecosystem diversity.
Factors influencing biodiversity include latitude, habitat complexity, climate, disturbances, and geographic isolation.
Threats to biodiversity
: habitat loss, overexploitation, pollution, climate change, invasive species, and diseases.
Conservation measures include protected areas, habitat restoration, conservation programs, and sustainable resource use.
Case studies
: conservation of tigers and coral reefs.
Individual actions and international efforts are essential for biodiversity conservation.