Communities and Ecosystems Flashcards
What abiotic factors do organisms need to adapt to?
– energy sources,
– temperature,
– the presence of water,
– inorganic nutrients, and
– other aquatic and terrestrial factors
Pelagic Realm
All open water
Benthic realm
Sea floor
Aphotic zone
insufficient light for
photosynthesis
Photic zone
where photosynthesis by phytoplankton and multicellular algae can occur.
Zooplankton
are abundant in the pelagic photic zone.
Coral reefs
Occur in the Photic zone
Intertidal zone
are where the ocean meets the land and the shore is pounded by waves during high tide
and exposed to the sun and drying winds during low tide.
Estuaries
are productive areas where a freshwater stream or river merges with the ocean.
Wetlands
are transitional between aquatic and terrestrial ecosystems.
What 2 categories do freshwater fall into?
- Standing water biomes (lakes and ponds)
- Flowing water biomes (rivers and streams)
Does warm or cold air contain more moisture?
Warm
Features of tropical forests
occur in equatorial areas,
– experience warm temperatures and days that are 11–12 hours long year-round, and
– have variable rainfall.
Brackish water
Water that contains salinity levels between that of the ocean and that of freshwater. ie. Salt marshes
Features of Savannas
– are warm year-round,
– have 30–50 cm annual rainfall,
– experience dramatic seasonal variation,
– are dominated by grasses and scattered trees, and
– have insects as the dominant herbivores.
Features of deserts
are the driest of all terrestrial biomes.
– They typically have low and unpredictable rainfall.
– The cycles of growth and reproduction in the desert are
keyed to rainfall.
– Deserts can be very hot or very cold.
Desertification
the conversion of semi-arid regions to
desert, is a significant environmental problem.
Features of chaparral
characterized by dense, spiny shrubs
with tough, evergreen leaves.
– mild, rainy winters,
– hot, dry summers, and
– vegetation adapted to periodic fires. Firestorms that
race through the densely populated canyons of
Southern California can be devastating.
Features of temperate grassland/prairies
are mostly treeless, except along rivers or streams,
– are found in regions of relatively cold winter
temperatures,
– experience precipitation of about 25–75 cm per year,
with periodic droughts, and
– in North America have historically been grazed by large
bison and pronghorn.
Features of temperate forests
- Temperate broadleaf forests
– grow where there is sufficient moisture to support the
growth of large trees,
– experience wide-ranging temperatures, and
– have high annual precipitation (75–150 cm). - These forests typically have a growing season of five to six
months and a distinct annual rhythm. - The canopy of a temperate broadleaf forest is more open
than that of a tropical rain forest, and the trees are not as
tall or as diverse.
Features of coniferous forests/taiga
the largest
terrestrial biome on Earth. The taiga is characterized by
– long, cold winters and
– short, wet summers.
Features of tundra
covers expansive areas of the Arctic between
the taiga and the permanently frozen polar ice.
* The treeless arctic tundra
– is characterized by permafrost, continuously frozen
subsoil, and
– may receive as little precipitation as some deserts.
Features of Polar Ice
covers
– land north of the tundra,
– much of the Arctic Ocean, and – the continent of Antarctica.
• Temperatures are extremely cold year-round and precipitation is very low.
• The terrestrial polar biome is closely interconnected with the neighboring marine biome.
Ecology
is the scientific study of the interactions of organisms and the environment.
Organisms can potentially be affected by many different variables, grouped into two major types.
- Bioticfactors
- Abioticfactors
- Bioticfactors
include all of the organisms in an area, the living component of the environment.
- Abioticfactors
are the environment’s nonliving component, the physical and chemical factors.
An organism’s habitat includes?
the biotic and abiotic factors present in its surroundings.
To be successful, organisms must be adapted to the abiotic factors present in their environments.
• Major factors include:
– energy sources,
– temperature,
– the presence of water,
– inorganic nutrients, and
– other aquatic and terrestrial factors.
Ecologists study interactions at several levels:
– organism
– population
– community
– ecosystem
Humans rely upon natural ecosystems to:
– supply fresh water and some foods,
– recycle nutrients,
– decompose wastes, and
– regulate climate and air quality.
• Wetlands
– buffer coastal populations against tidal waves and hurricanes,
– reduce the impact of flooding rivers, and
– filter pollutants.
Natural vegetation helps to…
– retain fertile soil and
– prevent landslides and mudslides.
Community Includes All the Organisms Inhabiting a Particular Area
• In the hierarchy of life, a population is a group of interacting individuals of a particular species.
• The next step up is a biological community, an assemblage of all the populations of organisms living close enough together for potential interaction.
ecosystem consists of….
– all the organisms in a community and
– the abiotic environment with which the organisms interact.
In an ecosystem:
– energy flow moves through the components of an
ecosystem and
– chemical cycling is the transfer of matter within the
ecosystem.
Ecosystems are supplied with a continual influx of energy from the sun and Earth’s interior. Except?
for meteorites, there are no extraterrestrial sources of chemical elements.
Biogeochemical cycles include
– biotic components
– abiotic components
– abiotic reservoirs
– biotic components
§ Organisms, anything living
– abiotic components
§ Rock, sand, water, minerals, wind
– abiotic reservoirs
§ where chemicals accumulate or are stockpiled outside of living organisms.
True or false, The Carbon Cycle Depends on Photosynthesis and Respiration?
• Carbon
– is the major ingredient of all organic molecules,
– has an atmospheric reservoir,
– cycles globally, and
– resides in plant and animal biomass, fossil fuels, soils,
sedimentary rocks, and as dissolved carbon.
The Nitrogen Cycle Depends on
Bacteria, true or false?
• Nitrogen is
– an ingredient of proteins and nucleic acids,
– essential to the structure and functioning of all
organisms, and
– a crucial and often limiting plant nutrient.
• Nitrogen has two abiotic reservoirs
1.the atmosphere, of which about 80% is nitrogen gas, and
2. soil.
Nitrogen fixation
converts N2 to compounds of nitrogen that can be used by plants.
Various bacteria in soil (and root nodules of some plants) convert gaseous N2 to compounds that plants can use, such as ammonium (NH4+) and nitrate (NO3−).
Every group of organisms plays a role in a given ecosystem, true or false?
True
Biodiversity includes:
- ecosystem diversity,
- species diversity,and
- genetic diversity.
Keystone species
• organism that helps define an entire ecosystem.
• Without its keystone species, the ecosystem would be
dramatically different or cease to exist altogether.
Most biodiversity loss is traced to four major threats:
– Habitat loss
– Introduced species
– Overharvesting
– Global climate chang
Introduced species
are those that humans move from native locations to new geographic regions, either intentionally or by accident
Overharvesting
is harvesting of organisms at rates exceeding the ability of their populations to rebound
Conservation biology
is a goal-driven science that seeks to understand and counter the rapid loss of biodiversity
Bioremediation
is the use of organisms—mainly prokaryotes, fungi, or plants—to detoxify polluted ecosystems
Biological augmentation
uses organisms to add essential materials to a degraded ecosystem
