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Chapter 25 - Populations and Ecosystems - Coggle Diagram
Chapter 25 - Populations and Ecosystems
Concepts
Ecology - study of organisms in relationship to all aspects of their surroundings
Population - all individuals of the same species in a a given area
Community - all populations in a given area
Ecosystem - all living and nonliving things in a given area
Plants in Relationship to Their Habitats
Habitat - set of conditions in which an organism completes its life cycle
operational habitat - aspects of the habitat that definitely affect a plant
Two types of habitat components
abiotic - nonliving and physical.
examples: climate, soil, latitude, altitude, fires, etc.
biotic - living factors
Abiotic Components of the Habitat
Climate
lowest temp. and highest temp. are more important than average
Soil Factors
Pioneers - first plants to invade a new soil
After years a thick soil with three distinct layers/horizons may develop
B horizon - where materials from A horizon accumulate and is rich in nutrients. Also called zone of deposition
C horizon - lowest layer. made of parent rock and rock fragments
A horizon - uppermost layer that consists of litter and debris. Also called zone of leaching
Latitude and Altitude
these heavily affect other abiotic factors
Disturbance
phenomena such as fires, landslides, snow avalanches and floods
Biotic Components of the Habitat
The plant itself
Other Plant species
mutualism - interaction between two organisms that benefits both
competition - interactions between plants which are disadvantageous
competitive exclusion theory - whichever species is less adapted is excluded from the ecosystem by superior competitors
Niche - each species is assumed to be adapted to a particular set of conditions
Organisms other than plants
Fungi
Animals
Prokaryotes
Commensal relationships - one species benefits and the other is unaffected
Predation - one species benefits and the other is harmed
The Structure of Populations
Geographic Distribution
Boundaries of the Geographic Range
Limiting Factor - the factors that effect a plants ability to spread throughout a geographic region
Local Geographic Distribution
There are three types of small scale, local distributions of individuals
Clumped distribution - when the spacing between plants is either large or small
Uniform distribution - type that occurs in orchards and tree plantations. All individuals are evenly spaced from their neighbors
allelochemics are chemicals that inhibit other plants thus creating these uniform zones
Random distribution - whenever there is no obvious pattern to individual distribution
Ages distribution: Demography
age distribution/demography: relative proportions of young, middle-aged, and old individuals
Two factors affect possible rate of population growth
Generation time - length of time from birth of one individual to the birth of its first offspring
intrinsic rate of natural increase / biotic potential - number of offspring produced by an individual that live long enough to reproduce under ideal conditions
carrying capacity - the number of individuals in each population that can live in a particular ecosystem
r- and K-Selection
r. is when a species population growth is limited by their biotic potential
Disturbances usually produce these such as floods and fires. This means that resources are plentiful for the surviving individuals
K. is the carrying capacity of the ecosystem
Conditions in a crowded habitat where the amount of resources is what limits the population
The Structure Of Ecosystems
Physiognomic Structure
Physiognomic structure is the physical size and shape of organisms and their distribution in relation to eachother and the physical environment
Temporal Structure
Temporal structure is the changes that an ecosystem undergoes with time
These timespans vary greatly
Species Composition- The number and diversity of species that coexist in an ecosystem
Trophic Levels - the various feeding levels or organisms
Secondary Consumers - Those who consume primary consumers
Tertiary consumers - Top carnivores which are not preyed upon by other animals
Primary Consumers - herbivores who eat primary producers. Typically small insects and mice. Are eaten by Secondary consumers
Decomposers - fungi and bacteria which breakdown the remains of all types of organisms.
Primary Producer - autotrophs who bring energy into the system. Typically through photosynthesis
