ecology unit 1

What is ecology?

the study of relationships between organisms

What do ecologists do?

Ecologists study the relationship between plants, animals and the environment

What things do ecologists study?

Population ecology, community ecology, ecosystem ecology, behavioral ecology

Example of an interaction that took place during the seed investigation

Seeds with apple juice grew mold that fed off of the juice

Hierarchy of Ecological Organization

Biodiversity

The number, and variety of living organisms in a given area, during a specific period of time; total genetic based variety of organisms

Trophic Levels of Consumers

Species Richness

the number of species in an area (ex. 3 types of grass in a field)

Species Abundance

the number of individuals per species (ex. 1 million oak trees)

Genetic Diversity

the range of different inherited traits within a species (ex. different dog breeds)

Habitat Diversity

the range of habitats present in a region (ex. desert, grasslands, oceans)

Taxonomy

how organisms are classified

Eubacteria

single-celled, no organelles (ex. E. coli, salmonella)

Eukaryota

1+ cells, have organelles (ex. fish, trees, dolphin)

Archea bacteria

single-celled, unique biochemistry, extremophiles (ex. cyanobacteria)

Viruses

NOT ALIVE - protein, not a domain (ex. COVID, flu)

Binomial Nomenclature

2-system identifying name used worldwide, "Genus species" (italicized)

Phylogenetic Tree

diagram that depicts the lines of evolutionary descent of different species, organisms, or genes from a common ancestor

Fungi

organisms that use glucose (ex. yeast, molds, mushrooms, and toadstools; separate from green plants)

Plants

organisms that create glucose through photosynthesis (ex. grass, trees)

Animals

organisms that use glucose (ex. humans, bears, tigers)

Protists

organisms that both make and use glucose; single-celled (ex. sea lettuce, kelp)

Species

A group of organisms that are closely related, who can mate to produce fertile offspring. All of the cats are feline, but each cat is a different species. "Genus species" name

Population

A group of individuals that belong to the same species and live in the same area.

Species life history

the pattern of survival and reproduction events typical for a member of the species (aka life cycle)

Habitat

Place where an organism lives

Niche

An organism's particular role in an ecosystem, or how it makes its living

Intrinsic rate of growth "r"

maximum rate of annual growth under ideal physical conditions

Population limiting factors

The reason why organisms don't reach "r" :
biotic (predation, parasites/disease, competition)
abiotic (weather, viruses)

Intraspecific competition

within the same species (ex. 2 wolves fighting over a dead fox)

Interspecific competition

between different species (ex. an alligator and a lion fighting over a buffalo)

Exponential Growth

J-curve, rate of growth is constantly increasing over time

Logistic Growth

S-curve, rate of growth grows then shrinks because of carrying capacity

Carrying Capacity "k"

maximum number of individuals an environment can support over a period of time; limits a population (over k = die off)

Community

A group of interdependent organisms inhabiting the same region and interacting with each other.

Symbiosis

A close relationship between two species that benefits at least one of the species

Mutualism

A relationship between two species in which both species benefit (ex. birds cleaning hippo's teeth)

Parasitism

A relationship between two organisms of different species where one benefits and the other is harmed (ex. tick on a dog)

Commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected (ex. burrs) - rarest!

Resource Partitioning

the division of resources to avoid interspecific competition for limited resources in an ecosystem; each organism occupies a different niche

Population Cycles

populations rise and fall over a predictable period of time
- predator population is usually less than prey population
- lag time due to reproduction delay

Why are nutrients recycled in an ecosystem?

Decomposers break down dead organisms into nutrients and gases so that they can be used by other organisms

Carbon Cycle

most of carbon is stored in the atmosphere (CO2), plants absorb it and turn carbon into glucose

Why is carbon important?

Carbon has 4 valence electrons, so it’s good at bonding to make other molecules. In other words, Carbon is the building blocks for many different chemicals.

Phosphorus

Phosphorous is used to make genetic material, and help make ATP, which allows organisms to store and release energy.

Sulfur

Sulfur gives proteins structure, and the proteins make us the way we are.

Nitrogen

Nitrogen is required to make amino acids, proteins, and genetic material, which are essential to life.

Tundra biome

low temperatures, little precipitation

Desert biome

little rainfall, extremely cold or hot

Forest biome

dominated by trees; temperate forests, tropical forests, and boreal forests

Grasslands biome

dominated by grass; warm, dry climate

Aquatic biome

freshwater and marine biomes

1st Law of Energy (Conservation)

regarding quantity/amount of energy
energy is neither created nor destroyed

2nd Law of Energy

regarding quality/type of energy
energy changes form over time and eventually becomes unusable

Entropy

the measure of the quality of the energy in the universe
any exchange of energy=waste heat and increase in entropy

Energy Flow in an Ecosystem

Energy Pyramid

A diagram that shows the amount of energy that moves from one trophic level to another in an ecosystem.

Plant Chemical Reactions

- plants capture solar E
- transform solar energy -> chemical energy (glucose)

Animal Chemical Reactions

- transform glucose -> ATP
- transform ATP -> kinetic energy (ability to move around and function)

Food Chain

hierarchical series of organisms each dependent on the next as a source of food.

Food Web

combination of all of the food chains in an ecosystem

Biomass

Total amount of living tissue within a given trophic level