Populations and Ecosystems
Populations and Ecosystems
Structure of ecosystems
: feeding levels
Herbivores: Primary consumers
carnivores: secondary consumers
omnivores: primary and secondary consumers
- the changes that an ecosystem undergoes through time.
: The number and diversity of species that coexsist in an ecosystem.
Example: jungle vs desert
Structure of populations
: environmental conditions that limit the growth, abundance, or distribution of an organism or a population of organisms in an ecosystem.
boundaries of Geographic Range
: the ability of a plant species to spread throughout a geographic area. Example in photo is the geographic range of hibiscus plants:
Example: Geographic range of saguaro cactus:
: Example: swamps cannot support cacti, deserts cannot support mangroves
lack of warm winters
Tropical plants die when too cold:
- lack of space limits growth
Local demographic distribution
: when there is no obvious, identifiable pattern to the position of individuals:
: when the spaces between the plants are either large, or small., but rarely average:
: when the individuals are evenly spaced from their neighbors. *usually on plantations or in orchards:
aka demography: the relative proportions of young, middle age and old plants
: the length of time from the birth of one individual to the birth of it's offspring.
annual: short generation time of 1 year or less
perennial: several years old before producing first offspring
intrinsic rate of natural increase/biotic potential
: the number of offspring produced that actually live long enough to reproduce under ideal conditions.
biotic potential =/= number of seeds produced
Plants in relationships to their habitats
: a set of conditions in which an organism completes it's lifestyle
: a biological community of interacting organisms and their physical environment.
Abiotic components: non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems
: a vertical section of the soil that is exposed by a soil pit.
: first plants to invade a new soil . Usually hardy. usually begin a chain of ecological succession that ultimately leads to a more biodiverse steady-state ecosystem
: the weather conditions prevailing in an area in general or over a long period.
Av'g temp of a habitat is less important as it's extremes: exactly how hot summers are, exactly how cold winters are
- each plant has it's own tolerance range, which determines where it lives. Tropical rainforest plants cannot handle the cold, wet winters of the deciduous rainforests of Oregon and Washington state.
Desert plants and swamp plants usually cannot switch places based on the root systems, as well as stomatal density and respiration rates of each
: some plants do better in humid environments rather than in non-humid environments
humidity loving plant
dry loving plant
Latitude and altitude
change the total daylight hours:
change the soil makeup
not fully shielded by Ozone layer and water vapor
physiological drought is frequent as water is frozen in the form of ice and snow
: natural phenomena that produce a significant & radical change in an ecosystem dramatically
biotic components: the living things that shape an ecosystem.
Things that affect the biotic ecosystem
the plant itself
Other plant species
Mutualism: symbiosis that is beneficial to both organisms involved.
competition: interaction between organisms, populations, or species, in which birth, growth and death depend on gaining a share of a limited environmental resource.
Filling a niche: The role or function of an organism or species in an ecosystem.
Competitive exclusion: two species that compete for the exact same resources cannot stably coexist.
organisms other than plants
: all components of a habitat whether they have a known or an unknown effect
Omnivores can eat both primary consumers and primary producers