Chapter 1- Ecology

Ecology

study of relationships among organisms and between orgs and the physical environment (ex. sun, minerals, water, etc.) HOW IT WORKS

Ecology influences

distribution and abundance of organisms, variety of species living together, and transformation and flow of energy

Individual Ecology

organismal ecology, Physiological and behavioral ecology

Physiological Ecology

where they study the evolution of physiological and anatomical mechanisms by which organisms adapt to challenges posed by physical and chemical variation in the environment

Behavioral Ecology

they focus on the evolution of behaviors that allow animals to survive and reproduce in the face of environment variation

Evolution

process by which populations change over time

Population Ecology

centered on the factors influencing population structure and process; processes are influenced by nonbiological and biological aspects of the environment

Population processes

adaptation, extinction, distribution and abundance of species, population growth and regulation, and variation in the reproductive ecology of species

Population

group of interbreeding individuals of a single species inhabiting a defined area, and make viable offspring

Community Ecology

study interactions between species that live contempareously (same time & place), emphasized the evolutionary effects of the interaction ; effects population structure or properties of ecological communities, studies species richness, community change, and community structure

Community question

How do species interact? How do these interactions affect coexistence?

Population question

what factors control zebra populations?

Individual question

how do zebras regulate their internal water balance?

community

an association of interacting species

ecosystem

biological community together with its associated physical and chemical environment

Ecosystem ecology

focus on ecological processes such as energy flow and decomposition

Landscape ecology

study of exchanges of materials, energy, and organisms with other communities and ecosystems

Biosphere ecology

highest; portions of the earth that support life including the land, waters, and atmosphere

ecosystem question

How does the fire affect nutrient availability in grassland ecosystems?

Microbial ecology

study of interactions among microorganisms and between them and their environment

Urban ecology

study of urban areas as complex, dynamic ecological systems, influenced by interconnected, biological, physical, and social components

observation

collection of data in unmanipulated setting

ex: counting & describing

in situ

in the habitat where the organisms live

MacArthur

observation research, observed warblers in spruce forests of NE North America

wanted to understand how several warbler species with similar ecological requirements could live together

determined each warbler species had a distinct feeding zone (partitioning) which reduced competition between warblers

Nadkarni

observation research, one of the first to study the ecology of the unseen world of forest canopy

by sampling nutrients of rainforests she found that 4x the nutrient content int the tree leaves were found in epiphytes

epiphytes

plants like orchids, ferns, and mosses that grow on tree trunks and branches

stable isotope analysis

isotopes of a chemical element have different atomic masses as a result of having different # of neutrons

water and nutrients can have different isotope signatures allowing us to trace them through ecosystems

Whitaker

stable isotope & genetic analysis; used to identify trophic relationships of Athene usamba (butterfly) found on acacia trees, ants have mutualism with the tree

hypothesized that the butterfly larvae might feed on ants or ant regurgitations

through DNA and nitrogen isotope signatures of the gut contents of butterfly larvae they found that the butterfly was herbivores and was eating the acacia tree itself

experiment

tests possible phenomenons; research that involves manipulation of variables of interest while holding others constant in order to test a hypothesis

ex situ

not int the natural environment

Galen

experiment, tested importance of bees for evolution of the alpine wildflower

hypothesized that larger flowers would have more seeds because they were more attractive to bees

compared seed set in plants that were pollinated by bees vs. hand pollinated & bagged (different sized flowers)

results: seed # increased with flower size but only when pollinated by bees, Bees prefer larger flowers and influenced the evolution of larger flowers to have greater fitness

Galen #2

natural experiment, investigate the impact of light and temperature on bees’. behavior during solar eclipse

with audio recordings they measured bee wing movement

results: decrease in movement during eclipse (dark), decrease was primarily due to light not temperature

modeling

creation and analysis of representations od data or ideas to provide insight or make predictions; usually how a system works

conceptual models

describe systems in pictures or diagrams

quantitative models

mathematical and may involve complex questions

Davis

studied pollen in lake sediments “growth layers”, tells history of vegetation, gained evidence that during climate change plants evolve and disperse (adaptation), discovered that trees move

climate and ecological patterns of the past can be used to make future predictions

1960s

when declines led to the establishment of international treaties and national laws to protect endangered species

CITES

Convention on International Trade in Endangered Species of wild fauna and flora (1973)- international treaty to protect endangered species from the threat of wildlife trafficking and trade

ESA

US Endangered Species Act (1973)- extended protection to all threatened and endangered vertebrate animals, invertebrate animals, and plants in the US and to species elsewhere around the globe listed as endangered under the CITES treaty, also identifies critical habitats

delisting

process to determine whether populations have recovered sufficiently to be removed from the ESA’s list of endangered species

ex. gray whale and bald eagle

DeGrasse Tyson’s Keystone Address

the thickness of the atmosphere around us is about as thick as the lacquer on a globe (thin); protects us from radiation

environmental science

interactions between the physical, chemical, and biological components of the environment including effects on all types of organisms (HUMNA IMPACT ON ENVIRONMENT)

Ecosystem Threats

Habitat Loss (#1), Invasive Species, Pollution, Direct Exploitation

habitat loss

leading cause of ecosystem threats

ex. deforestation & habitat fragmentation

deforestation

clearing out Earth’s forest at a massive scale

habitat fragmentation

don’t have to take out the whole habitat in order to make the habitat an ineffective place

invasive species

when new species is introduced to a new area and won’t have competition or predation Lin in their natural habitat, leads to increased reproduction, messes up balance of organisms in the new habitat and causing local organisms to go extinct

ex. Burmese python

pollution

substance that is added to the environment, which has a harmful or poisonous effect

ex. air and water (chemical spill, human waste, litter)

CO2 pollution

(air & water poll.) increase makes a change in atmospheric chemistry and climate, leads to global warming, happening rapidly, can also go in water making carbonic acid-changing the acidity (pH) of the ocean

Direct exploitation

ex. overfishing

overpopulation

makes us the problem, consuming more resources and producing more waste

65 mya

mass extinction (70%) due to asteroid

250 mya

mass extinction (95%) Pangea broke up and caused a lot of volcanic eruption ( changed atmosphere and ocean chemistry)

6th mass extinction

human caused; average species extinction is supposed to be 4 per year and we are losing 10-20,000 per year

species richness

number of species

succession

gradual change of plant and animal communities after a disturbance (ex. fire or hurricane) or creation of a new substrate (ex. retreat of glacier leaving bedrock)

food web

feeding relationships in an ecological community

phytoplankton

plantlike and can’t swim against water, conducts photsynthesis, primary producers

ex. diatoms & dinoflagellates

zooplankton

animal like, primary consumers

keystone species

species which despite low biomass, exerts strong effects on the structure of the communities they inhabit

Giant Kelp

example of keystone species Macrocystis pyrifera

sea otters live in there and feed on sea urchins, humans hunted otters leading to extirpation in certain area, which leads to increase in sea urchins overwhelming the kelp and collapsing the community

Macrocystis is brown algae (laminara) and sea urchins use their Aristotle Lantern to scrape algae off so they can chew on the holdfast (rootlike) breaking the kelp off- taking away the community

HIPPO

acronym for habitat loss, invasive species, pollution, population, and overharvesting

Anthropocene

“ Age of Man”, our current era, era affected by humans

epipelagic

upper ocean level

Decomposer

orgs that cycle nutrients - nutrients put in soil and plants take it up to be eaten by animals ( nitrogen - amino acids and phosphorus-nucleic acids)

ex. bacteria and fungus

entropy

energy is lost as heat as organic material is consumed and transferred from one tropic level to the next, how we maintain body temperature

producer

organism that can fix energy

consumer

organisms unable to conduct energy fixation and must consume and digest the chemical energy fixed by producers

Competitive Exclusion Principle

by Gause; predicts 2 or more species with the same requirements (ecological niche) can’t coexist

ecological niche

environments factors that influence the growth, survival, and reproduction of a species (requirements and resources; can be spatial, resources, or temporal

niche partitioning

natural selection drives competing species into different patterns of resource use (diff. requirements)

carbon-14

what will radioactively decay into nitrogen-14 because it is not stable

carbon-12 and carbon-13

stable carbon isotopes and not radioactive, there are more 12s than there are 13, plants prefer 12 for photosynthesis while consumers don’t, the higher on the food web the greater the amount of 13 in the tissues from feeding on other organisms- determines trophic structure

same for N15/N14

trophic level

feeding position go an organism in an ecosystem

scientific method

information, question, hypothesis, and then test hypothesis, and data

independent variabl

factor being manipulated

dependent variable

what is being measured form manipulation

controlled variable

any other variables that could affect how the dependent variable behaves

experimental group

what/ who is being tested/ manipulated

control group

what/ who is not being exposed to manipulation

confounding

inability to determine if the results are due to manipulation the independent variable or other variables that was not controlled ( do replication)

null hypothesis

there will be no difference between the experimental and control group

alternative hypothesis

there will be a significant difference between the experimental and control groups

lab scale

highly controlled but small scale

field scale

manipulation of an environment in the real world

observational scale

no manipulation

natural scale

environmental change