Please enable JavaScript.
Coggle requires JavaScript to display documents.
Populations and Ecosystems (Plants in relationship to their habitats…
Populations and Ecosystems
Plants in relationship to their habitats
habitat= set of conditions in which an organism completes its life cycle
animals are migratory during certain parts of the year
plants are migratory, however certain parts of it are
spores
pollen
seeds
how much of surroundings is part of habitat is debated
depends on factors affecting certain plants
some components impact directly
operational habitat
pollinators
components of habitat has two types
abiotic= nonliving
biotic= living
Abiotic components of the habitat
climate
critically important to all organisms
extremes: lowest winter temp and highest summer temp
most species are restricted to certain regions due to not being able to live in required climates
orchids restricted to tropics because they are frost free habitats
=rainfall, temp, humidity, and winds
moisture= rain or snow
supplies water but can also damage
seasonal extremes or timing of precipitation
growing season
determined by last date of the last severe killing frost of spring and the first killing frost of autumn
length must be adequate for repopulation
numerous metabolic processes respond to abiotic factors
tolerance range
between high and low extremes
growth and reproduction
Soil factors
formed from breakdown of rock
vary in amounts of micronutrients and macronutrients
all rock deficient in nitrogen
first invaders of new soil= pioneers
tolerate severe conditions
often associated with nitrogen fixing prokaryotes
change soil conditions as they live on it
water holding capability increased and chemical weathering accelerated
after many years it develops soil profile with three horizons
A horizon= upper zone and zone of leaching and nutrients from it washed down to next layer
B horizon= middle layer and is zone of deposition. Nutrients from A accumulate making it rich in nutrients
C horizon= bottom layer composed of parent rock and fragments
Latitude and altitude
many factors
length of days and seasonal variations varied
amount of light energy
soil formation affected and temperature
high altitudes= high winds, poor soil, much of the year is cold, and snow and ice is only way to get water causing drought
Disturbance
phenomenas
fires, landslides, snow avalanches, and floods
produce a radical change in an ecosystem quickly
affect biotic factors directly
eliminates many or all individuals of an area
man made= insecticides, hunting, and habitat destruction
Biotic components of the habitat
the plant itself
individuals modify a habitat by just being in it
habitat modification can be beneficial, detrimental, or neutral
oak forests modify habitat by producing a dense canopy that shades forest floor for oak and beech seedlings to grow
=beneficial in aiding of successful reproduction
other plant species
possibility of interaction created by several individuals occupying an area
mutualism= interaction beneficial
competiton= disadvantageous
limited supply of resources used by both species
competing for light, soil nutrients, water, and pollinators
result= competitive exclusion meaning whichever species is less adapted is excluded from the ecosystem by superior competitor
very little competition due to each species having a niche
adapted to a set of particular conditions
alternative to this theory is is species overlap in their tolerance
long term competition= natural selection causes modification of species
geographic ranges
diversity of biotic and abiotic factors
causes different subpopulations to form
subspecies ecotypes formed that are specialized in response to a certain ecosystem factor
transparent tests performed to see if ecotypes really exist
parents grown in a intermediate place, or common garden
Organisms other plants
animals, fungi, and prokaryotes
interrelationships can be beneficial or detrimental
mutualism
pollination
seed dispersal by frugivores (fruit eating)
common relationships
one species benefits and the other is unaffected
birds nesting in trees
Predation
one species benefits and the other is harmed
one seeks the other for food or other resource
herbivores eat plants, process is herbivory
browsing= twigs and leaves of shrubs
grazing= eating herbs
Pathogenic
fungi and bacteria
cause disease or kill plant quickly
some fungus may for mutualistic relationships with plants
Structure of populations
Geographic Distribution
Boundaries of the geographic range
ability of a plant to spread is a result of its abiotic and biotic adaptations of the area
health of plant determined by limiting factor
applies to all aspects of a plants interactions with its habitat
plant receives more of the factor limiting it causes increased growth till another limiting factor pops up
any factor of the ecosystem can act a limiting factor
water, temp, and soil richness
biotic factors are also critical
pollination or seed dispersing can not occur unless if their animal partners are not present
soil factors produce abrupt boundaries due to mineral composition and texture
Local geographic distribution
three types
random
no obvious, identifiable pattern to position of individuals
clumped
spacing between plants is either small or large but rarely average
uniform
all individuals are evenly spaced
roots of individuals establish zones that prevent germination or growth of others
release chemicals= allelochemicals
inhibition= allelopathy
Age distribution: Demography
proportions of age groups (young, old, and middle-aged)
two factors affect population growth rate
generation time
length of time from birth to death of one individual
biotic potential
number of offspring produced by an individual that live long enough to reproduce
measured under ideal conditions
but conditions often do not occur in nature
population becomes large and competition occurs
number of individuals that can live in a particular ecosystem is limited
represented by K
represented by r
r- and K- selection
population undergoes young phase in which resources are plentiful
growth limited by r
carrying capacity governed by K as competition occurs
r- selection
disturbance usually produces r conditions
biotic potential becomes limiting factor
mutations that increase r are selectively advantageous
r-selected species typically are annuals or small shrubby perennials
increasing species in the area causes cause population to start to fall
K- selection
population close to carrying capacity causes selection of phenotypes different from those that are beneficial in a dsiturbed habitat
K-selected species also face intense competition and adaptations occur
The Structure of Ecosystems
Physiognomic Structure
physical size and shape, and distributions in relation to each other and physical environment
life forms
Temporal structure
change an ecosystem undergoes with time
time span can be a day, seasons, or decades
plants change with seasons
spring is a time of renewed activity
flowers and new leaves
fruits and mature seeds during the summer
late summer and autumn herbs die, and trees and shrubs develop resting buds
dormancy
tropical ecosystems
wet and dry seasons
Species composition
number and diversity of species that coexist in an ecosystem
depends on climate, soil, tolerance ranges
stressful climates + poor soil= low number of species
mild climates + rich soil= high number of species
competition is intense, but natural selection has resulted in habitat partitioning
species occupying a narrow portion of various resource gradients
increased number of species= more niches that can be filled
Trophic levels
feeding levels
ecosystem contains autotrophs that bring energy into the area
photosynthesis= all energy input
autotrophs= primary producers
first step of any food web
energy and nutrient supply to herbivores
herbivores= secondary consumers
herbivores preyed upon by carnivores
carnivores= secondary consumers
omnivores exist at both trophic levels
decomposers= fungi and bacteria
1 more item...
break down remains of all types of organisms
energy and carbon flow
passing of energy and carbon through trophic levels
used for respiration
ATP, heat, CO2, and H2O
CO2 released back into atmosphere for photosynthesis
minerals
flow through ecosystem
absorbed by plants from soil for amoinos, ATP, and coenzymes
passed onto herbivores
decomposers release minerals in body that remain after death
maybe be completely lost from an ecosystem
carried away by rain water, stremas, or errosion
carried to ocean to become part of marine ecosystem
Energy pyramid
movement of energy and biomass from one trophic level to the next
difficult to measure biomass in an ecosystem
