BIO SECTION 3 ecology LECTURES 25-35

Population

Population

A group of individuals of the same species living in the same area that interact and interbreed.

Commonness in Species

Varying definitions include range size, local vs global abundance, and local vs global biomass.

Temporal Shift

Falcon migration patterns change presence depending on the time of year, not all niches occupied at once.

Biomass Measurements

Measured through carbon, humans and livestock make up most of the mammalian biomass.

Patterns of Organism Dispersion

Can be clumped, uniform, or random, influenced by abiotic and biotic factors.

Exponential Growth

Occurs with unlimited resources, as seen with reindeer on an island in Alaska.

Density-Dependent Mortality

Higher density leads to fewer hiding places from predators.

Survival Curves

Type 1 (humans), Type 2 (squirrels), Type 3 (ants) based on risk of death throughout life.

Community

Populations of different species living in the same area.

Diversity

Measured through species richness and species evenness, best protected by focusing on evolutionarily distinct species.

Foundation Species

Create structure and conditions necessary for ecosystem function.

Keystone Species

Disproportionally large effect on the environment compared to abundance.

Trophic Cascades

Effects of predators on prey populations that cascade through the food chain.

Rewilding

Re-establishing ecological processes and ecosystem functions using natural management strategies.

Ecosystem

Sum of all organisms and abiotic factors in a given area.

Limiting Factors

Prevent biomass accumulation, organisms can't grow without key resources.

Eutrophication

Runoff from fertilizers causing algae growth, leading to marine dead zones.

nitrogen and phsophrous

Temperature Rainforest

Biome found at high latitudes and altitudes with cool weather, high precipitation, and conifers dominating, including regions like Ireland and Great Britain.

Temperate Broadleaf Forests

Biome characterized by deciduous trees, cold winters, warm summers, and no extreme dryness.

Grasslands

Biomes located in the interior of continental masses and arid coastlines at temperate latitudes, with lower precipitation, low soil nutrients, and a high range of temperatures.

Savannahs

Biomes dominated by grasses, found in sub-tropical areas with seasonal rainfall, drought tolerance, and scattered trees like the Acacia tree.

Desert

Biomes located at 20-30 latitudes in both hemispheres, receiving less than 250 mm of precipitation and experiencing desertification due to climate change.

Mediterranean Scrub

Biome with hot dry summers, cool wet winters, scrub, and shrub vegetation adapted to fire, dominated by shrubs.

Tropical Forest

Equatorial biome with constant rainfall, little temperature variation, high biodiversity, and threats from climate change and deforestation.

Biodiversity Loss

Decline due to factors like land use change, habitat loss, pollution, overexploitation, invasive species, and climate change, leading to the need for targeted conservation efforts.

what kind of distribution does bristol whitebreak have

restricted distribution only found in the UK

fire moss and brown rats protray what kind of distribution

global

temporal shift

migration, changes habitat depending on time of year, falcon

wild land animals

most species are rodents, individuals are bats, and niomass is mammalls mostly white tialed deer

how do populations change

birth and immigration and death and emmigration

example of exponential growth

reindeer on an island in alaska; unlimited resources no predator

relationship between growth rate and carrying capacity

as N approaches K growth rate declines as resources become limited

what species portrays a type 2 survival curve where the risk of death remains stable throughout life

ground squirrel

what type survival curve do humans illistrate

type 1, highest risk with age

what is type 3 survival curve

ants, lowest risk when young

semelparity versus itereoparity

breeding onces with a large volume of offspring versus multiple times like humans

how is diversity measured

species richness and eveness

how is diversity best protected

focusing on evolutionarily distinct species

describe the difference between foundation species and keystone species

foundation species(bottom up) creates the structure and function for the ecosystem to operate so something like a beaver and a keystone species(top down) has a disproportionately large effect on the ecosystem despite their smaller population size

portfolio effect/redundancy

many species doing slightly different things iss productive

ecosystem

sum of all the organisms in a given area and their abiotic interactions

do distruptive influences need to happen in habitable landscapes

yes things such as fire need to be allowed to happen without dominating

rewilding

aims to restablish ecosystem functions by reintroducing native speices

why can reforestation be bad

planting trees in the wrong areas compromises other landscapes

threatens grasslands and wetlands

african nonforest areas are threatened due to reforestation

GPP(gross primary productivty)

• amount of energy converted into organic material by autotrophs

NPP(net primary productivity)

• GPP minus the energy used by autotrophs for themselves such as respiration

NEP(net ecosystem productivity)

• total amount of biomass added to the ecosystem by all organisms 

bogs have water and sunlight but what nutrient are they lacking

DO

eutrophication

• runoff from fertilizers causes an increase in nitrogen and phosphorus thus increasing algae growth leads to marine dead zones

-more algae growth-> no sunlight plants die to lack of O2

bioaccumlation versus biomagnification

bioaccumlation is the build up of a toxin in an organism whereas biomaginification is the higher trophic level organisms having more of a toxin

phenology

how organisms are influenced by seasonal changes

two ways temperature determines gender

females at extreme temperatures and males in the middle or a single defining temeprature

tuatara

due to increasing temepratures more and more males are being produced

sea turtle

more females being produced with rising temperature so their are more nests and a population boom

bateman principle

female skewed population increases, male skewed population decreases

mesopredator

less apex predator and more mid level domestic predators

what does birds being fed in the winter cause

less need for migration

why are galapagos finch species decreasing

they are defined by the beaks but feeding on human food is decreasing the differences between speices

what is the interval for climate

average of at least thirty years

biomes sitting in the middle of climate zone…..

require larger biome changes to notice biolgoical effects

why is there an oscillation in seasons of CO2 concentration

minor oscillation in CO2 is due to more land mass in the northern hemisphere and during the winter less photosynthesis and more respiration produce more CO2->about 1 ppm difference in seasons

greenhosue effect

• CO2, water vapour, and other greenhouse gases reflect infrared radiation toward earth increasing temperature

• There is 13ppm discrepancy between the amount of CO2 we would expect and the actual amount in the atmosphere that we don't understand

IPCC

UN body for addressing climate change

energy supply versus demand side actions

supply is using solar and wind energy whereas demand is reducing demand so better insulating homes etc

Paris climate agreement

194 countries signed and agreed to keep earths temp below 1.5C increase

niche construction

organisms altering their environment

human heat stress

• lobal mean warming of 7C would create zones where metabolic heat dissipation in humans would be impossible therefore questioning their habitability

bark beetle infestation in SW USA forest

warmer winters weakened the trees and made them more susceptible to disease indirect consequences

plant embolism

• formation of bubbles in the xylem (water-conducting vessels)

-droughts cause this and even when water is available often it is too damaged to take advantage and uptake the water

are phenological events extending into autumn or starting earlier in spring

starting earlier in spring

will crop yeilds in high or low latitudes increase

high latitudes, wheat will also increase

what determines a biome

temeprature and precipiation

why do organisms need nitrgoen

amino acids, proteins, chlorophyll, soils are becoming depleted and atmospheric nitrogen is hard to access due to triple-bond

why do organisms need phopshorous

DNA phospholipids and ATP, found from weathering of rocks

what altidude is nitrogen limited

 high altitude, nitrogen tends to be limited due to younger soils

what information does the red list provide

extinction risk of species

30X30 intitaive

• >intiatiave to protect thirty percent of land and sea ecosystems by 2030 however the issues is neocoloniams or indigenous peoples rights because the person deciding what thirty percent to protect arent the same people living there