Community and Ecosystem Flashcards
assemblage of populations living close enough together for potential possible interaction
community
is a collection of populations of all the organisms which occur together in a given place and time.
community
is also commonly used to refer to a subset of populations within the whole community, for example we talk about plant communities, insect communities, arthropod communities, small mammal communities, etc.
community
dependent on species diversity and certain species in the community
community structure
is commonly used to refer to the limitations set by species interactions on which species can coexist with which other
community structure
is also used to describe the physical arrangement of species in a community, such as the vertical arrangement of species in a forest (trees, shrubs and ground growing herbaceous (non-woody) plants.
community structure
Limitations set by species interactions on which species can coexist with which others
community structure
– limitation to coexistence, and they can apply to single species, as well as to groups of species.
assembly rules
can have emergent properties which arise from these interactions - properties which could not be predicted by studying the individual populations in isolation.
ecological communities
such as competition, predation, herbivory, parasitism, and commensalism affect the structuring of communities
interspecific interactions
total number of species in the community
species richness
proportion of each species in the community
relative abundance
way an organism uses its environment, species thus become more specialized
niche
include the total range of environmental conditions that are suitable for existence without the influence of interspecific competition or predation from other species
fundamental niche
part of the fundamental niche actually occupied by the species
realized niche
Characteristics of community (biological structure) (2)
dominance
species diversity
Characteristics of community (physical structure) (2)
vertical stratification
horizontal pattern
vertical structure/layering include
light
temperature
oxygen
where two or more different communities meet
edge
when edges are stable or permanent
inherent edge
temporary which result from natural disturbances or human activities
induced edge
consist of edges and border
boundary
where two or more communities not only meet but intergrade
ecotone
the transition layer between the warmer mixed water at the surface and the cooler deep water below
thermocline
succession of new environment (no plants)
primary succession
occurs on habitats previously lacking plants
➢example include sand dunes, lava flows, and other bare surfaces
➢generally lacking a seed bank
primary succession
recovery from a disturbance in existing environment (plants previously
secondary succession
following disturbance after blow-down or logging
secondary succession
include fires, floods, hurricanes, human activity)
disturbances
why does succession occur?
➢Early arriving plants can tolerate harsh conditions, facilitate later arriving species
➢Sometimes due to chance who arrives first
➢Type of climax community depend on climate, terrain, and history
why do communities stay the same?
➢Stability is lack of change
➢Resiliency is ability to return to a given state following a disturbance
➢Complexity does not ensure stability
assemblage of communities interacting with another together with the environment a distinct area
ecosystem
Characteristics of ecosystem
➢Interdependence of biotic and abiotic factors
➢Homeostasis – optimum condition and balance in nature
➢Self-sustaining – continuous flow of nutrient and energy
➢Consisting of the major communities
Ecosystem classification based on temp (4)
▪Torrid
▪Tropics
▪Temperate
▪Frigid
Ecosystem classification based on habitat or biome
aquatic
terrestrial
can be classified into freshwater and marine waters
aquatic biomes
fresh water biome (2)
lotic
lentic
running waters
lotic waters
standing waters
lentic waters
marine waters divided into:
pelagic
benthic
refer to waters divided into neritic and oceanic
pelagic water
consists of the water column of the open ocean and can be further divided into regions by depth.
pelagic zone
province above continental shelft
neritic province
province of the oceanic basins
oceanic province
refers to the bottom which includes the supralittoral, littoral, sublittoral
benthic waters
located in the sublittoral shelf
continental shelf
located in the bathyal zone
continental slope
located in the abyssal zon
abyssal plane
largest environment, it covers 70% of the Earth’s surface
marine
covers 70% of the Earth’s surface
➢Form a single vast interconnected water mass partially separated into divisions by the continents
➢Characterize by general equality in the composition and amount of dissolved substances (average of 35 ppt) due to continuous diffusion of sea water by means of currents, tides, and storms
marine
marine depth varies from intertidal zones to depths of ____ km
10.8
Temperature ranges from ___ in the tropics to -_____ in the Arctic, rarely fluctuates more than 5 celsius
32
-2.2
the ocean floor, including the intertidal zone (littoral zone)
benthic region
Include organisms that live on the floor of the continental shelf, of the continental slope, and the abyssal plain
Majority of the organisms are invertebrates that serve as food for the species of marine vertebrates
benthic region
the open waters, include floating organisms (planktons) e.g. phytoplanktons and zooplanktons and free-swimming organism (nektons) e.g. fishes, turtles, marine mammals
pelagic zone
Divided into neritic province and oceanic province
pelagic zone
shallow water above the continental shelf, with more nutrients and organisms because sunlight penetrate the waters up to the bottom
neritic province
– above the high tide mark
supratidal
between the high and low tide
intertidal
below the low tide mark
subtidal
the region of the open sea beyond the continental shelf, above the oceanic basins
oceanic province
receives abundant sunlight, planktons are abundant
epipelagic
(200-1,000m) – known as the twilight zone, fishes are the primary vertebrates, with cetaceans as frequent visitors
mesopelagic
(1,000-4,000) – area of cold, quiet water, permanent darkness, and increased pressure, inhabited by a lesser number of fishes with bioluminescent organs
bathypelagic
3,000-6,000m) – comprises a
region with almost
physical environment i.e. continually dark, cold (4oC) ad unchanging composition inhabited by rattails (Macrouridae), brotulas (ophidiidae), lumpfishes (cyclopteridae), and batfishes (ogrocephalidae)
abyssopelagic
beyond 6,000 meters, still unexplored, the deepest living fish is known as Abyssobrotula galatheae (Ophidiidae), a blind elongate fish that feeds on benthic invertebrates and lives at adepth ranging from 3,100 to 8,370
hadopelagic
-contain brackish water, a mixture of fresh and salt waters, located where rivers flow into the oceans
estuaries
Trap the nutrients brought in from the sea by the tides and prevent the escape of nutrients carried by the rivers
estuaries
Called as nurseries of the sea because half of all marine fishes develop in the protecetive environment of estuaries, rich in larval shrimps, mollusk and fishes
estuaries
important habitat for many vertebrates, located adjacent to estuaries
salt marshes
form in warm, shallow seas provide a haven for many invertebrates and fishes
coral reefs
shrub and tree species that live along shores, rivers, and estuaries in the tropics and subtropics
mangrove
Grows mainly in coastal saline or brackish water
mangrove
smallest environment which may include swamps, rain puddles, ponds, hot springs, lakes, streams, and rivers
freshwater
Classified into lotic system (flowing water) and lentic system (still water)
freshwater
Temperature ranges from freezing to boiling, water maybe clear or turbid with a maximum depth to 1,700 m or more
freshwater
affect the stream community
pH
temperature
richer natural waters in carbonates, bicarbonates, and associated salts supporting a more abundant aquatic life and larger fish populations than streams with acid waters
high pH (alkaline)
streams shaded by trees and shrubs are cooler than those exposed to direct sunlight
➢in slow-flowing streams where current is at minimum, streamlined forms of fishes
are present such as small
-mouth bass (Micropterus dolomieu), shiners (Notropis, Cyprinell) and darters (Ethiostoma, Percina)
➢bottom-feeding fishes such as catfish are found at the silty bottom of freshwater habitats
freshwater
standing water, include pond and lakes, subdivided into three zones
lentic
– shallow water region with light penetration up to the bottom in lentic zone
littoral zone
open water zone up to the depth of effective light penetration, photosynthetic zone (lentic zone)
limnetic zone
bottom and deep water beyond the depth of effective light penetration in lentic zone
profundal zone
is the interface between land and a river or stream
riparian region
moving organism
nektons
floating organism
planktons
rooted in the lake bottom, but their leaves and stems extend out of the water
emergent
those that are wholly underwater and may be rooted or unrooted.
submergent plants
running water, includes rivers and streams
lotic zone
shallow water where velocity is great enough to keep the bottom clear of silt and other loose materials providing a firm substrate
rapid zone
deeper water where velocity of current is reduced and silt and other loose materials settle to the bottom providing a soft
pool zone
two or more species compete for a resource that is in short supply
competition
two species cannot coexist in a community if their niches are identical. The one with slight reproductive advantage will eliminate the other
competitive exclusion principle
differences in niches that enable allopatric species to coexist (ecological niche, fundamental niche, realized niche)
resource partitioning
predator eats its prey
predation
acute senses (heat sensors, chemical sensors, sharp eyesight), structures (claws, teeth, fangs, poisons); speed and agility; and camouflage
adaptations for stalking prey
structural (thorns, spines) or chemical (toxic or bitter taste)
prey or plant defenses
cryptic coloration (Shape of animal, deceptive markings), aposematic coloration (bright coloration as a warning of toxicity)
passive hiding
eats part of the plant, plants have various chemicals and mechanical defenses against herbivory, and herbivores have specialized adaptation for feeding
herbivory
– the parasite derives nourishment from the host, does not usually kill the host
parasitism
A realized niche refers to the wide range in which the organisms may survive in the absence of a competitor
False
Which of the following biomes receives the least amount of precipitation per year?
desert
__ is the other term for running water ecosystems
lotic
__ is the other term for standing water ecosystems
lentic
Profundal zone receives little amount of light in the lake
true
Hadopelagic is the deepest zone of the oceanic region
true
__ is the series of predictable changes that occur in a community over time.
succession
Savanna refers to tropical grassland
true
__ is the region of the oceanic province characterized by permanent darkness and inhabited by bioluminescent organisms.
bathypelagic
__ is also known as the open waters, which includes all the floating and swimming organisms in the ocean/sea.
pelagic zone
It is considered to be the richest biome in terms of number and abundance of species.
tropical rainforest forest
__ is the ocean floor that includes the
continental shelf, continental slope and the abyssal plain.
benthic region
Lotic refers to running waters
true
__ is the transition between fresh water ecosystem and marine ecosystems.
estuary
Supratidal is located between high tide and low tide mark
false
Rapid zone of lentic waters refers to shallow water where velocity of current is high
false
__ is the above high tide mark of the neritic province
supratidal
Tundra is composed of coniferous forest dominated by cone-bearing trees such as spruce, fir and pine
false
Which biome is nearest to the polar region?
tundra
Primary succession occurs when there is no pre-existing community
true
____ is the region of the oceanic province that receives abundant sunlight, where phytoplankton are abundant
epipelagic
___ is the series of changes that occur in an area where no ecosystem previously existed
primary succession
Desert support organisms adapted to arid conditions
true
Estuaries are termed as “nurseries of the sea”
true
Ponds and lakes are concrete examples of lotic freshwater bodies
false
commensals benefit from the host but the host is unaffected by the relationship
commensalism
refers to group of populations occupying an area at a given time
community
may be based in number, biomass or basal area, and influence or position within a community
dominance
relates to both the number of species ( species richness ) and the relative abundance of individuals among species ( species evenness)
species diversity
species that controls the diversity of community
keystone species
functional role of each species in a community
niche
includes the total range of environmental conditions that are suitable for existence without the influence of interspecific competition or predation from other species
fundamental niche
part of the fundamental niche actually occupied by the species.
realized niche
determined by life forms of plants or vegetation
land
Vertical structure in forest (5)
canopy
understory
shrub layer
herb layer
forest floor
the primary site of energy fixation through photosynthesis with major influence in the forest. If the canopy is dense and closed, light levels are low and the understory and shrub layers will poorly developed
canopy
consist of trees and tall shrubs lower than the canopy
understory
shrubs are characterized by having woody stem
shrub layer
are plants with soft green stem
herb layer
nature of __ layer depend on soil moisture and nutrientcondition and
slope position
herb
site where decomposition takesp lace
forest floor
aquatic ecosystem determined by light penetratipn
photic
aphotic
receiving sunlight
photic
doesn’t receive sunlight
aphotic
upper most layer receiving much sunlight, high temp
epilimnion
second layer characterized by a thermocline ( steep and rapid decline in temp)
metalimnion
lower cold layer
hypolimnion
the upper layer contains more oxygen than the lower and bottom layer
amount of oxygen
where two or more different communities meet
edge
when edges are stable or permanent
inherent
edge which may result from natural disturbances or human activities
temporary
consist of edges and border
boundary
where two or more communities not only meet but intergrade
ecotone
emergent properties of a community (5)
scale
spatial structure
temporal structure
species richness
diversity
is the size of a community. Provided that the area or habitat is well defined, a community can be a system of almost any size, from a drop of water, to a rotting log, to a forest, to the surface of the Pacific Ocean.
scale
the way species are distributed relative to each other. Some species provide a framework that creates habitats for other species. These species, in turn create habitats for others, etc. Example: Trees in a rainforest are stratified into several different levels, including a canopy, several understories, a ground level, and roots. Each level is the habitat of a distinct collection of Some places, such as the pools of water that collect at the base of tree branches, may harbor entire communities of their own.
spatial structure
is the timing of the appearance and activity of species. Some communities, i.e., arctic tundra and the decay of a corpse, have pronounced
temporal species, other communities have less.Example: Many desert plants and animals are dormant most of the year. They emerge, or germinate, in response to seasonal rains. Other plants stick around year round, having evolved adaptations to resist drought.
temporal structure
is the number of species in a community. Clearly, the number of species we can observe is function of the area of the sample. It also is a function of who is looking. Thus, species richness is sensitive to sampling procedure
species richness
is the number of species in the community, and their relative abundances.Species are not equally abundant, some species occur in large percentage of samples, others are poorly represented.Some communities, such as tropical rainforests, are much more diverse than others, such as the great basin desert.
diversity
is often expressed using Simpson’s diversity index
diversity
diversity index
D = 1-S (Pi)^2
investigating community structure by grouping organisms at levels higher than the species
trophic level
Community with higher diversity are
➢More productive and more stable regarding their productivity
➢Better able to withstand and recover from environmental stresses
➢More resistance to invasive species, organisms that become established outside their native range
are events such as floods, fire, droughts, overgrazing, and human activity that damage communities, remove organisms from them, and alter resource availability
disturbances
creates opportunities for new species to invade an area and establish themselves. These species modify the environment, and create opportunities for other species to invade. The new species eventually displace the original ones. Eventually, they modify the environment enough to allow a new series of invaders, which ultimately replace them, etc.
disturbances
change involving a series of species replacement in a community following a disturbance
succession
communities are constantly changing
non-equilibrium model
begins in a habitat lacking soil; this might occur following a volcanic eruption.
primary succession
the sequence of species on newly exposed landforms that have not previously been influenced by a community, e.g., areas exposed by glacial retreat.
primary succession
begins when soil is already present but it has been disturbed and returns to a natural state, as in an abandoned cornfield.
secondary succession
occurs in cases which vegetation of an area has been partially or completely removed, but where soil, seeds, and spores remain. Early in succession, species are generally excellent dispersers and good at tolerating harsh environments, but not the best interspecific competitors.
secondary succession
is divided into large biogeographic units called biomes.
biosphere
large biogeographic units identified mainly by their climax community
biomes
as a particular mix of plants and animals adapted to live under certain environmental conditions.The average temperature and rainfall
influences where the different
biomes are found on the surface of the Earth. Climate, and mainly solar radiation and topography, is the principle determinant of the distribution of biomes.
biomes
5 major kinds of biomes
aquatic
forest
tundra
desert
grassland
include all watery regions of the earth
aquatic
both lentic and lotic biomes including lakes and ponds and wetlands
freshwater
largest biome, covering greatest amount of surface area, the open ocean
marine
vary in temperature and dominated by trees
forest biomes
generally dominated by deciduous trees, which shed their leaves with changing of seasons
temperate
closest to the equator, marked not by the four seasons that occur in temperate forest but rather a dry and wet seasons
tropical
northernmost forest biome, colder climates are dominated by coniferous trees, often on mountains
taiga
frigid, treeless, and have short growing season
tundra biomes
situated at high latitudes, most northern artic regions have a
permafrost ground with very small, hardy plants
arctic
located at high atitudes, these biomes are marked by mountainous regions
apline
are frequently found at the center of continents and are characterized by very little rainfall or available water
desert
almost no plant growth
hot and dry
some precipitation, may be hot or cold
semi-arid
markedly unstable, prone to fog blowing in from the ocean
coastal desert
dominated by tall grasses, with few shrubs or trees
grassland biomes
mainly tropical grassland environment, consisting primarily of tall grasses with some shrubbery, largely known for its diverse wildlife
savanna
dryer environment with tall grasses are periodically curbed by natural wildfire
temperate
study table
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