Biology 1102: Ecology

The ability to do work or bring about change.

Energy of motion. 

Stored energy. 

Energy stored in chemical bonds. 

Energy of motion. 

Energy cannot be created or destroyed, but it can be changed from one form to another.

Energy cannot be changed from one form to another without a loss of usable energy.

The relative amount of disorganization.

Converting solar energy into chemical energy of carbs. 

CO2 + 6H2O = C6H12O + 6O2

Carbon Dioxide + Water = Glucose + Oxygen

6O2 + C6H12O6 = CO2 + 6H2O

Oxygen + Glucose = Carbon Dioxide + Water

An organism that carries on photosynthesis (self feeding). 

Organisms that feed on other organisms (rely on outside nutrients). 

Light dependent. 

Light independent. (NADP+ links these reactions)

The study of the interactions of organisms with each other and their physical environment. 

How are organisms adapted to their environment?

Individual --> Population --> Community --> Ecosystem --> Biosphere

Species distribution throughout the environment.

Describe and develop testable hypothesis and models that explain and predict the distribution and abundance of populations and species.

Influences/controls productivity of ecosystems, communities, and populations. 

Individuals within populations adapt to changes in the environment. Causes variation within the population. 

Influenced by population dynamics. 

Non-living aspects of an ecosystem. 

Living aspects of an ecosystem. Various populations of species that form a community. 

According to food source. 

Particular type of heterotroph that breaks down non-living organic matter (Chemicals from producers and consumers; waste and carcasses) into simpler form (inorganic matter) which can be reused by producers. 

• - Energy Flow and Chemical Cycling
• - Food Webs
• - Trophic Levels
• - Ecological Pyramids 

Energy enters and ecosystem when producers absorb solar energy.

Energy enters an ecosystem when producers absorb inorganic nutrients. 

Diagram representing interactions between all populations within an ecosystem. 

What make up Food Webs. Represents a succession of organisms that eat another organism and then are eaten themselves. 

Composed of all the organisms that feed at a particular link in a food chain. 

Primary producers. 

Primary consumers. What eat the producers.

Secondary consumers. Carnivores, omnivores. 

Tertiary consumers. Carnivores that eat carnivores. 

Apex Predators. Highest level (top) of food chain. 

The number of organisms at each trophic level multiplied by their weight. 

Representation of the relationships between biomass (biological productivity) and trophic levels. A snapshot in time of an ecological community.

Interactions between populations.

Assemblage of populations of various species living close enough for possible interactions.

• - The way of life of a species.
• - Role a species plays in the community
• ex: Habitat a species needs + interactions with other organisms.

Interspecific interactions.

• -How long it takes to reach reproductive maturity
• -Level of reproductive output

• (r-strategist)
• Individual size: Small
• Life Span: Short
• Development: Fast
• Offspring: Many; Little or no care for young; high mortality rate
• Reproduction: Early
• Environment: Ok with variable
• Regulated by density independent factors

• (K-strategist)
• Individual Size: Large
• Life Span: Long
• Development: Slow
• Offspring: Few, large size; Lots of and long term care; low mortality rate
• Reproduction: Late
• Enviornment: Adapted to stable
• Regulated by density dependent factors

• Individual Size: Large
• Life Span: Long
• Development: Slow
• Offspring: Many; No care for young; Relatively high mortality rate
• Reproduction: Late
• Environment: Mostly Stable

• - Abiotic factors (weather, natural disasters)
• - Effects are the same for all population sizes
• - Regulate Opportunistic Species

• - Biotic factors (Competition predation, symbiosis, disease)
• - Effects depend on the size of the population
• - Regulate Equilibrium Species

• - When two or more species try to utilize the same limited resource (ex: light, water, nutrients, space)
• - Degree of competition proportional to amount of ecological niches

No two species can occupy the same ecological niche at the same time if resources are limited; one species will out-compete the other.

Resource Partitioning

• - Allows division of feeding niches
• - Decreases the competition between the two species and allows occupancy of different niches and therefore survival

• When one organism (predator) feeds on another (prey).
• - Predator and prey populations tend to cycle instead of maintaining a steady state.

• - Carnivorous
• - Herbivory

Present when each of two species adapts in response to selective pressure imposed by the other.

• - Physical: claws, teeth, stingers, poison...
• - Sensory: eyesight, smell, hearing...

• - Behavioral: hiding, fleeing, herds/shoals, warning calls...
• - Morphological: Camouflage, spines, warning coloration, mimicry...
• - Chemical: alkaloids, sprays...

A harmless species mimics a harmful one.

Two species mimic each others defenses (ex: stinging)

• Refers to close interactions between members of different species.
• - 3 traditional types:
•      - Parasitism
•      - Commensalism 
•      - Mutualism

• A parasite derives nourishment from another organism (host)
•   - parasite benefits, host is harmed
•   - Exist in all kingdoms
•   - The host:
•       - A place to live and/or reproduce
•       - Mechanism for dispersing offspring to another host needed in the life cycle
•         - Many hosts have primary and secondary hosts
•           - The secondary host may be a vector that transmits the parasite to the next primary host

• One species benefits, the other is neither benefited or harmed.
• - One provides a home and/or transportation for the other

• Both organisms benefit.
• - The degree of benefit may not be equal

• Study of population dynamics in relation with their environment.
• - Populations are very dynamic

• - Boundaries/territories
• - Spacial Structure (density-distribution-dispersion)
• - Dynamic Behavior
• - Temporal Continuity
• - Spatial Continuity

• - Each population has a particular pattern of growth
• - The population size can change according to a per capita rate of increase = growth rate

Maximum reproductive capacity of a population under optimum environmental conditions.

• - Optimum growth curve
• - Has two phases:
•     - Lag: Growth is slow because of small population
•     - Exponential growth phase: Growth accelerates, and the population exhibits its biotic potential
• - Generally unsustainable due to environmental resistance.

• Encompasses all those enviornmental conditions that prevent populations from reaching their biotic potential.
• - Reproductive potential
• - Availability of food
• - Presence and absence of disease
• - Presence and absence of predators

The optimum growth curve (J-Shaped) is displaced (S-Shaped).

• The intensity of environmental resistance increases as population grows larger, until population growth levels off. 
• - Lag: Growth is small because population is small
• - Exponential: Growth accelerates and population exhibits its biotic potential
• - Deceleration: rate of population growth slows down (death rate = birth rate)
• - Stable equilibrium phase occurs at the carrying capacity of the environment

Number of individuals of a species that a given environment can support.

A group of individuals born at the same time.

• Type 1: Most survive until old age (ex: humans)
• Type 2: Decreases consistently over time (ex: songbirds)
• Type 3: Most die at young age (ex: oysters)