Chapter 1: Intro to Ecology

Ecology

the scientific study of the interactions of among organisms and the environment

Environmentalism

Ideology and social movement aimed at sustainable development and protection of natural ecosystems 

Producers (autotrophs)

convert light or chemicals into resources

Example of producer.

plants

Consumer (heterotrophs)

obtain energy from other organisms

Mixotrophs

switch between producers and consumers

Mixotroph example

venus fly trap that digest insects and also uses photosynthesis

Scavengers

consume dead animals

Decomposers

break down detritus (waste left behind) into simpler recyclable material

Decomposer example

fungi

Detritovores

decomposers that break down dead organic material into small pieces by ingesting it

Detritovores example

earthworms that tunnel through soil, swallowing dirt and decaying leaves

3 types of symbiotic relationship

1) mutualism

2) commensalism

3) amensalism

mutualism

An interaction between 2 species in which each species receives benefits from the other

mutualism example

honeybees that pollinate flowers as they obtain nectar

commensalism

an interaction in which 2 species live in close association and one species recieves a benefit while the other experiences neither a benefit or a cost

commensalism example

plants that produce fruits containing tiny barbs stick to hairs of mammals so their plant seeds are dispersed and the animal is not harmed

amensalism

one organism recieves a negative effect and the other is unaffected

amensalism example

tall forest trees block sunlight from smaller understory plants

What are the 6 levels of organization in eceology?

1) individual

2) population

3) community

4) ecosystem

5) landscape

6) biosphere

Level 1: individual

living being; the unit of natural selection

Give an example of an ecologist’s perspective of the individual level.

An ecologist may ask why trees are dominant in warm, moist environments, whereas shrubs with small, tough leaves dominate environments with cool, wet winters

Adaptations

a characteristic of an organism that makes it well suited to its environment

Individual approach

Understand how adpaattions or characteristics if an individual enable it to survive 

Give an example of an adaptation.

enhanced kidney function helps desert animals conserve water

Population

individuals of the same species in a particular area; unit of evolution

Give an example of a population.

All of the red foxes living in 50 square miles

What constitutes a border in a population?

Natural, such as where a continent meets an ocean, or political, such as man made geographical borders

Population approach

Seeks to understand what drives variation in the composition of individuals overtime

Community

all populations living in a particular area

Give an example of a community.

The red foxes, gray wolves, and white-tailed deer in teh same area

Community approach

Studies the diversity and interactions of organisms living together in the same place

Ecosystem

one or more communities of living organisms interacting with their nonliving physical and chemical environments

Give an example of an ecosystem.

The entire forest community plus the soil chemistry, local rainfall, sunlight filtering through the canopy, and temperature swings

Ecosystem approach

studies storage and transfer of energy and matter

Landscape

2 or more ecosystems connected by the movement of individuals populations, matter and energy

Give an example of a landscape.

how the red fox travels through the farmland and wetlands to hunt

Landscape approach

Studies spatial arrangement of habitats and influence on population, community, and individual

Biosphere

Includes all ecosystems on Earth

Biosphere approach

studies movement of energy and chemicals over Earth’s surface

Give an example of a biosphere approach.

winds blowing over the Sahara Desert in Africa pick up a plume of soil from an ancient lake high in nutrients which is then blown across the ocean to the Amazon to fertilize the rainforest

Dynamic steady states

when the gains and losses of ecological systems are in balance

Give an example of a dynamic steady state.

birds and mammals continoulsy lose heat in a cold environment, but this is balanced by heat gained from metabolism of foods

Whats the dynamic steady state on the individual level?

food in energy and energy expended

Whats the dynamic steady state on the population level?

births in and deaths out

Whats the dynamic steady state on the community level?

colonization by new species and extinction of species

Whats the dynamic steady state on the ecosystem level?

solar energy and matter in and energy and matter out

Whats the dynamic steady state on the landscape level?

energy and matter entering from other ecosystems and energy and matter leaving TO other ecosystems

Whats the dynamic steady state on the biosphere level?

solar energy in and energy radiated to space

Evolution

change in the genetic composition of a population overtime

4 mechanisms of evolution

1) natural selection

2) migration

3) mutation

4) genetic drift

Natural Selection

change in the frequency of genes in a population through differential survival and reproduction of individuals that possess certain phenotypes

Fitness

the survival and reproduction of an individual

Genetic Drift

random change in genetic composition of a population

Types of genetic drift

founder effect and bottleneck effect

founder effect

small group from population moves away to start a new population

founder effect example

invasive species

bottleneck effect

natural disaster shrinks existing population

migration

immigration and emigration

mutation

random changes in genetic makeup of an individual

in what cases is natural selection a faster mechanism of evolution?

when selection is stronger, heritability is greater and there is more variability in a trait

do allele frequency problem

yuh

habitat

physical setting of organism

niche

range of abiotic and biotic conditions an organism can tolerate

niche example

different insects prefer to feed on different crop species that may be growing in the same field which showcases same habitat with different niches

2 parts of niches

1) requirement niche

2) impact niche

requirement niche

the biotic and abiotic requirements of a species

impact niche

the effect of a species on abiotic and biotic factors

Hutchinsons n-dimensional niche

total combination of all environmental conditions and resources a species needs to survive and reproduce where n=# of factors

manipulative experiment

process by which a hypothesis is tested by altering a factor that is hypothesized

what are 3 alternatives to manipulative experiments?

1) natural experiment

2) observational experiment

3) mathematical models

natural experiments

an approach that relies on natural variation in the environment

observational experiment

make deductions from patterns in nature

mathematical models

set of equations that correspond to hypothesized relationships among biotic and abiotic