biol 2170 final

1st law of thermodynamics

energy is neither created nor destroyed

2nd law of thermodynamics

the entropy of an isolated will tend to increase

autotroph source of energy

sunlight or H2S

autotroph source of matter

they produce it themselves from inorganic matter

primary producers

plants, algae, protists, cyanobacteria

heterotroph source of energy

pre-exisiting organic matter

heterotroph source of matter

pre-existing organic matters

secondary producers

animals, fungi, protists

plant preferred energy storage

carbohydrates - easier to break down but less kj/g

animal preferred energy storage

lipids - harder to break down but much lighter

photosynthetic equation

6H20 + 6CO2 + solar energy = C6H120 + 06

gross primary production

amount of energy fixed by photosynthesis

net primary production

amount of energy remaining after respiration

efficiency of NPP

NPP divided by total solar energy

primary production efficiency

phytoplankton < forests < herbaceous plants < agricultural crops

factors limiting marine primary production

light - more light available at the surface and dependant on seasons

nutrients - N main limiting factor (no bacteria), upwelling brings nutrients up to photic zone

factors limiting marine primary production

light - less light in winter & with more depth

nutrients - P main limiting factor (leeched out to ocean)

temperature - limited by cold temps, esp growing season, more variation than in ocean

factors limiting terrestrial primary production

water availability - more precip means more NPP

temperature - cold temps limiting. metabolic rate increased w higher temps, also determines length of growing season

nutrients - N-P-K main limiting factors, slow decomp rates also limit

energy not used

energy that won’t be ingested

gross energy intake (I)

ingested energy

egested energy (F)

energy that won’t be digested

assimilated energy (A)

molecules broken down and absorbed through stomach wall

urinary waste (U)

waste byproducts of energy digestion

metabolizable energy (M)

energy that can be used for production

maintenance or respiration (R)

resting energy (minimum energy use, sleeping & natural bodily functions) and activity

production (P)

growth and reproduction, net secondary production

secondary production efficiency

consumer efficiency/conversion efficiency. conversion of other organic matter to own organic matter

most efficient SP

carnivores because they’re consuming material as animal tissue not plant tissue

efficiency of SPs

insects (carnivores > detritivores > herbivores) > non-insect inverts > fish > birds and mammals

why are birds/mammals so low?1\`

we have homiothermy = we control our body temp

amount of net PP in the ecosystem

more PP, more 2P

more PP, more food

more PP, more herbivore biomass

amount of PP biomass consumed by heterotrophs - forests

tropical - 7, temperate - 5

plants have evolved to be difficult to consume

amount of PP biomass consumed by heterotrophs - grasslands

10

90% doesn’t get eaten, plants don’t grow year round, limited to growing season & yellow leaves are poor in nutrients

amount of PP biomass consumed by heterotrophs - open ocean

40

single-celled primary producers not swamping, consistent pp throughout year

amount of PP biomass consumed by heterotrophs - oceanic upwelling zones

35

lots of single-celled pp but swamping occurs

swamping

1 burst of extreme growth of a population at 1 point in time, limited growth of that population at other times.

food pyramid

\~10% loss at every level (sun to 10 000 pp to 1 000 pc to 100 sc to 10 tc)

factors limiting secondary production

amount of NPP

amount of PP biomass consumed

conversion efficiency

organismal ecology

closest link between evolution and ecology

organismal ecology goal

determine the function of an organism’s traits, and how those traits help it survive, grow, and reproduce in its natural enviroment

ecophysiology

study of the physiological adaptations that allow organisms to survive, grow, and reproduce

behavioural ecology

study of the behavioural adaptations that allow organisms to survive, grow, and reproduce

biophysics (physical ecology

study of the structural (strength of structures) adaptations that allow organisms to survive, grow, and reproduce

shelford’s law of tolerance

each individual has upper and lower tolerance thresholds for environmental conditions, affecting its ability to survive, grow, and reproduce

h2o

main solvent for living organisms

life in deserts main challange

water availability

desert definition

area recieving on average

drought resister

remain active in deserts during driest period

drought evaders

do not remain active in desert during driest periods

individuals evade drought through behavioural/physiological adaptations ex. migration (b), dormancy (p)

PLANT DRs - store water

thick tissue able to store water in large quantity

root system that sucks up water very fast

PLANT DRs - minimize water loss

minimize thick water cuticle that waterproofs the surface

reduced leaves to reduce surface areas (ie cacti needles)

trichomes reduce airflow on leaf surface and reflect light to reduce heating

Crassulacean Acid Metabolism

open stomata to capture CO2 at night

have PEP mlcl

some CO2 dissolves into water and creates an acid environment

does P/S during the day w/ CO2 captured at night

SLOW GROWTH

ANIMAL DRs - store water

can metabolize to release water

camels and dramidaries store on back to reduce insulation

ANIMAL DRs - minimize water loss

waxy exoskeleton of anthropods = waterproof surface of body

reptile scales = waterproof surface of body

no transpiration

very concentrated excretory products

active only at night

some animals get all water from dry seeds

PLANT DEs

dormancy as seeds or roots

ANIMAL DEs

migration during dry season

dormancy - hibernation (winter) estavation (summer)

cold water mammals

homiotherms, insulatory layer of fat around their whole body

cold water invertabrates

isosmotic - allow salts from water to enter their bodies and if water is liquid, their tissues won’t freeze

plasma freezing point -1.73 C

cold water surface fish

produce anti-freeze proteins in winter

cold water deep fish

live in supercooled state - can never come in contact with crystalization triggers

crystalization triggers

ice crystals, impurities, shock

population

group of individuals of a same species at a same time in a same place

population ecology

interested in the abundance and distribution of a population

goal of pop eco

to understand the mechanism controlling the distribution and abundance of populations

extirpated

population has dropped to zero locally

extinct

species exists nowhere on earth

pop eco forms the basis of

fisheries and wildlife management, conservation biology

population parametres

birth rate, death rate, immigration, emigration

births

include sexual and asexual reproduction

deaths

death of an individual from any cause

immigration/emigration

arrival/departure of an extant individual that was/will be enmeshed in the population

exponential growth equations

r = b - d

Nt = Noe^rt

change in N = bN - dN

logistic growth equations

K - N/K

dN/dt = rN(K - N/K)

carrying capacity (K)

max population size that can be supported by the available supported

determined by the amount of resources available in the environment and the requirements of the individuals of the given species

occurs where b = d

community ecology brief history

1700s & 1800s sending out naturalists

determined range of organisms

found that some spp are always found together

associations

plants that are always found together

communities

an assemblage of different species (populations) living in a given area at a same time

goal of community ecology

to determine why groups of species love together as members of a community and how species of a community influence each other

trophic relationships

feeding relationships between 2 organisms

food chains

arrows tend to follow direction of energy transfer

pp tend to be on the bottom

food web

sum of all the food chains in the community

very difficult to encapsulate all the relationship between community members w out losing parsability

guild

group of species within a community that use a common set of food in a similar manner

functional role

what role a group is performing in a community

ex. primary producers, grazers, filter feeders, scavengers, predators

advantages of guild concepts

1. simplifies the community from a large number of species to a smaller number of function groups
2. reveals the level of redundancy of functional roles to see how crucial each species is
3. indicates species most likely to compete for food: competition for food higher between among of a same guild than different guilds

keystone species concept

a sp can be a keystone sp IF a func role is occupied by a single species and that func role is critical to the community THEN that species is a keystone species

bottom-up model

abundance at all trophic levels is determined by the requirements of the pp (eg nutrients) at the bottom of the food web

top-down model

abundance at all trophic levels is determined by the top lebel of the food web

also called trophic cascade model

top-down-bottom-up model

contains both, func groups closer to the top influnced by top-down model, closer to the bottom influenced by bottom-up model

biodiversity

the diversity of life in all its forms

includes species richness, genetic diversity, ecological (functional) diversity, ecosystem diversity

average rate of extinction

up to 10 000/year, or 27/day

alpha diversity

diversity within a community

beta diversity

diversity among communities of a region

gamma diversity

diversity among communties over a broad geographical region

species richness

amount of species present in a given area

limitation of species richness

counts rare and abundant species as equal

heterogeneity indices

combine species richness and species eveness

shannon weiner heterogenity index

sum of (pi)(logpi)

s = total # of spp in the community

i = sp identity number

pi = proportion of individuals of the total sample belonging to the ith sp

when do ecologists quantify biodiversity

to compare the diversity of 2 or more communities to decide where to extract resources or understand what factors impact communties

to monitor a community over time

to obtain baseline data for a community

EIA

environmental impact assessment

Alfred Russel Wallace

pioneered biodiversity research