52 Introduction of Ecology and the Biosphere Flashcards
1
Q
What is ecology divided into?
A
Global ecology, landscape ecology, ecosystem ecology, community ecology, population ecology and organismal ecology.
2
Q
What is global ecology?
A
The study of how the regional exchange of energy and materials influences the functioning and distribution of organisms across the biosphere.
3
Q
What is landscape ecology?
A
The study of the factors controlling exchanges of energy, materials, and organisms across multiple ecosystems.
4
Q
What is ecosystem ecology?
A
The study of the community of organisms in an area and the physical factors with which those organisms interact.
It emphasises energy flow and chemical cycling between organisms and the environment.
5
Q
What is community ecology?
A
The study of how interactions between species, such as predation and competition, affect community structure and organization.
6
Q
What is population ecology?
A
The analysis of factors that affect population size and how and why it changes through time.
7
Q
What is organismal ecology?
A
The study of how an organism’s structure, physiology, and behavior meet the challenges posed by its environment.
It is further divided into physiological ecology, evolutionary ecology and behavioural ecology.
8
Q
Define ecology?
A
The scientific study of the interactions between organisms and the environment.
9
Q
What is the global ecosystem called?
A
The biosphere
10
Q
Define biosphere.
A
The sum of all the planet’s ecosystems and landscapes
11
Q
Define landscape
A
A mosaic of connected ecosystems
12
Q
What is the marine equivalent of ‘landscape’?
A
A ‘seascape’
13
Q
Define ecosystem.
A
The community of organisms in an area and the physical factors with which those organisms interact
14
Q
Define community
A
A group of populations of different species in an area.
15
Q
Define population.
A
A group of individuals of the same species living in an area.
16
Q
What is an example of a question asked in global ecology?
A
How does ocean circulation affect the global distribution of crustaceans?
17
Q
What is an example of a question asked in landscape ecology?
A
To what extent do the trees lining a river serve as corridors of dispersal for animals?
18
Q
What is an example of a question asked in ecosystem ecology?
A
What factors control photosynthetic productivity in a temperate grassland ecosystem?
19
Q
What is an example of a question asked in community ecology?
A
What factors influence the diversity of species that make up a forest?
20
Q
What is an example of a question asked in population ecology?
A
What environmental factors affect the reproductive rate of locusts?
21
Q
What is an example of a question asked in organismal ecology?
A
How do hammerhead sharks select a mate?
22
Q
What is the north most tropic called?
A
The Tropic of Cancer
23
Q
What is the south most tropic called?
A
The Tropic of Capricorn
24
Q
Why are equatorial regions typically warmer?
A
When sun hits the equators it is more or less overhead. In the poles this light is at a oblique angle so not as intense.
25
What causes the global air currents?
As air warms at the equators it rises. This updraft forces it north or south where it cools and sinks.
The suction causes by the air rising at the equator pulls the air from the north/south back down to the equator forming a current.
26
What is a typical pattern of rain forests and deserts on dart?
Rain-forests are often located at the equator. Areas on the tropics of cancer and capricorn are typically deserts.
27
How many degrees form the equator is the tropic of capricorn?
23.5º S
28
Why are deserts typically found at the tropics and rain forests at the equator?
The air what rises at the equator loses its water as it rises. This cause rain to fall on the equator.
As this wire reaches the desert regions at the tropic it picks up the air and carries it to the equator.
Thus water is carried from the deserts to the rainforest regions.
29
What are the main winds called?
The ‘westerlies’ are from the tropic of cancer to the north pole and from the topic of capricorn to the south pole.
The ‘northeast trades’ are from the tropic of cancer to the equator.
The ’south east trades’ are from the tropic of capricorn to the equator.
30
What does the name of a wind i.e. ‘westerly’ mean?
This states the direction it is FROM. Therefore a westerly wind would come from the west to the east.
31
At what degree of latitude is the arctic circle?
60ºN
32
At what degree of latitude is the antarctic circle?
60ºS
33
Define climate.
The long term prevailing weather conditions of a region.
34
What are the main factors of climate?
Temperature, precipitation, sunlight and wind.
35
What is climate divided into?
Microclimate and Macroclimate.
36
Define ‘macroclimate'
Climate patterns on the global, regionally and landscape level.
37
Define ‘microclimate'
Very fine, localized patterns, such as those encountered by the community of organisms that live in the microhabitat beneath a fallen log
38
What are currents that exist in a circle called?
‘Gyre's
39
What are the main Gyres?
The North Pacific Gyre, South Pacific Gyre, North Atlantic Gyre, South Atlantic Gyre and the Indian Ocean Gyre
40
Besides the Gyres, what are the major ocean currents?
The 'antarctic circumpolar current’ which circumnavigates the pole.
the ‘labrador' current’ which travels south from Canada.
41
What causes the seasons?
As the earth orbits the sun it has a content tile tot 23.5º
As the earth moves this tilt means that for some portion of the year the southern hemisphere is leaning away and the northern hemisphere is leaning towards the sun. In this case the northern hemisphere is in summer.
42
What are the days that represent a turning point in the seasons called?
The March equinox, September equinox, June solstice and December solstice.
43
What happens during an equinox?
The earth is arranged so that neither hemisphere is pointing towards or away form the sun.
Therefore in both hemispheres the day is exactly 12 hours.
44
What happens during a solstice?
The earth is arranged so that one hemisphere is leaning the most prominently to the sun. The other hemisphere is as tilted in the opposite direction as it ever will be.
Therefore one hemisphere will experiences its longest day and the other will have its shortest day.
45
How does the June solstice differ from the December solstice?
In the June solstices the Northern hemisphere has its longest day while the Southern hemisphere has its shortest,
The December solstice is the opposite: Northern has shortest day, Southern longest.
46
How do mountains affect climate?
As winds hit the mountains the air flows up the mountain. This causes them to cool and drop precipitation.
Therefore the front side receives hight precipitation. This means that when the is at the ‘leeward side’ on the other side it has less moisture. Therefore the ‘leeward side’ is in a ‘rain shadow.'
47
What can factors that affect a microclimate be divided into?
Abiotic and biotic
48
What are some examples of microclimates?
The area under a tree is sheltered from light and rain.
A fallen log provides shelter for many insects.
A cleared area has more direct sunlight so is often warmer.
49
How can global warming affect trees?
It can affect air current and thus precipitation and thus causes trees to move away form drier areas.
The change in temperature limits the range in which their pollinators live and thus the range in which they can live.
50
What is the are in which a species lives in called?
Its ‘range'
51
How can the climate of a region be predicted?
With a 'climograph'
52
How does a climograph work?
It has annual mean precipitation on the x axis and mean temperature on the y axis.
Within the plot of the graph are shaded areas that specify a climate type.
The region is then plotted on the graph with the shaded area it falls in predicting its climate.
53
What is a ’biome’?
A major life zone characterized by vegetation type (in terrestrial biomes) or by the physical environment (in aquatic biomes)
Each biome is characterised by microorganisms, fungi, and animals adapted to that particular environment.
54
In what biome is arbuscular mycorrhizae most frequently found?
Temperate regions.
55
What are the boundaries between terrestrial biomes called?
‘Ecotones'
56
What is an ‘ecotone’?
The boundary between two terrestrial biomes
57
How wide is a typically ecotone?
It varies considerably.
58
What are the major terrestrial ecosystems?
Tropical forrest, desert, savanna, chaparral, temperate grassland, northern coniferous forest, temperate broadleaf forest and tundra
59
How stable are biomes?
Not: they are dynamic and exist in a ‘dynamic equilibrium’ due to many ‘disturbances'.
60
In terms of ecology, what is a disturbance?
A event that changes a community such as by removing organisms from it or affecting resource availability.
61
What are some examples of ecosystem disturbances?
Fire, storms, pest outbreaks or human activity.
62
Why are disturbances important to an environment?
- By removing a predator they can allow its prey to increase in population
- By burning the leaf litter, forest fires remove old trees and thus allow new ones to grow.
- It can expose new habitats such as a log falling of a tree during a storm.
63
In what biomes are wildfires considered essential?
Grasslands, savannahs, chaparral and many coniferous forests.
64
What is the distribution of tropical forests?
Equatorial and subequatorial regions
65
What is the distribution of deserts?
Deserts occur in bands near 30° north and
south latitude or at other latitudes in the interior of continents (for instance, the Gobi Desert of north-central Asia).
66
What is the distribution of savannah?
Equatorial and subequatorial regions
67
What is the distribution of chaparral?
It is found across the world particularly in midlatitude coastal regions like California, South Africa and southern France.
68
What is the distribution of temperate grasslands?
Across the world but primarily in the northern Hemisphere.
They are typically at the interior of continents such as at the centre of the US and in central Russia.
69
What is the distribution of northern coniferous forests?
Extending in a broad band across northern
| North America and Eurasia to the edge of the arctic tundra,
70
What is the distribution of temperate broadleaf forests?
Found mainly at midlatitudes in the Northern Hemisphere, with smaller areas in Chile, South Africa, Australia, and New Zealand
71
What is the distribution of tundra?
Tundra covers expansive areas of the Arctic, amounting to 20% of Earth’s land surface.
High winds and low temperatures produce simi- lar plant communities, called alpine tundra, on very high mountaintops at all latitudes, including the tropics.
72
Where are the ‘Pampas’ found and what biome are they?
In Argentina and Uruguay. They are Temperate Grasslands.
73
Where are ‘Puztas’ found and what biome are they?
In Hungary. They are Temperate Grasslands.
74
What are ’Northern Coniferous Forests’ also called?
Taiga
75
What does ’Taiga’ refer to?
A northern coniferous forest.
76
What is the largest biome on earth by land area?
The northern coniferous forests i..e Taiga.
77
What are the typical precipitation of Tropical Rainforests?
Rainfall is relatively constant, about 200–400 cm annually. In tropical dry forests, precipitation is highly seasonal, about 150–200 cm annually, with a six- to seven- month dry season.
78
What are the typical precipitation of Deserts?
Low and highly variable, generally less than 30 cm per year.
79
What are the typical precipitation of Savannah?
Rainfall is seasonal and averages 30–50 cm per year. The dry season can last up to eight or nine months.
80
What are the typical precipitation of Chaparral?
Precipitation is highly seasonal, with rainy winters and dry summers. Annual precipitation generally falls within the range of
30–50 cm.
81
What are the typical precipitation of Temperate Grassland?
Precipitation is often highly seasonal, with relatively dry winters and wet summers. Annual precipitation generally averages between 30 and 100 cm.
Periodic drought is common.
82
What are the typical precipitation of Northern Coniferous Forests?
Annual precipi- tation generally ranges from 30 to 70 cm, and periodic droughts are common.
However, some coastal coniferous forests of the US have 300 cm of rain per year
83
What are the typical temperature of Tropical Rainforests?
High year- round, averaging 25–29°C with little seasonal variation
84
What are the typical temperature of Deserts?
Temperature is variable seasonally and daily. Maximum air temperature in hot deserts may exceed 50°C Often very cold at night
Iin cold deserts air temperature may fall below –30°C.
85
What are the typical temperature of Savannah?
Warm year-round, averaging 24–29°C, but more seasonal variation than in tropical forests.
86
What are the typical temperature of Chaparral?
Fall, winter, and spring are cool,with average temperatures in the range of 10–12°C.
87
What are the typical temperature of Temperate Grassland?
Winters are generally cold, often below –10°C.
| Summers, are hot, often approaching 30°C
88
What are the typical temperature of Northern Coniferous Forests?
Winters are very cold, summers reasonably warm
Some in Siberia go from -50ºC in the winter to 20ºC in the summer.
89
What are the typical plants of Tropical Rainforests?
Tropical forests are vertically layered with a canopy layer, one or two ‘subcanopy’ layers then shrubs at the bottom. There are generally fewer layers in tropical dry forests.
Broadleaf evergreen trees are dominant in tropical rain forests, whereas many tropical dry forest trees drop their leaves during the dry season.
Epiphytes such as bromeliads and orchids generally cover tropical forest trees but are less abundant in dry forests. Thorny shrubs and succulent plants are found in some tropical dry forests.
90
What are the typical plants of Deserts?
Due to low water the vegetation is sparse. Most plants are shrubs and herbs that grow in the intermittent wet periods.
Most plants are succulent to store water between wet periods. This water is often protected with spines and chemical defences
91
What are the typical plants of Savannah?
Vast grasslands with scattered trees, often with small leaves and spines.
92
What are the typical plants of Chaparral?
Mostly shrubs and small trees, along with many kinds of grasses and herb.
Adaptations to drought include the tough evergreen leaves of woody plants to water loss.
Many shrubs produce seeds which only germinate during the frequent fires.
93
What are the typical plants of Temperate Grassland?
Mostly grasses and ‘forbs’, Some grasses grow up to 2 metres.
The plants re well adapted to periodic droughts and fires.
94
What are the typical plants of Northern Coniferous Forests?
Dominated by cone-bearing trees, such as pine, spruce, fir, and hemlock.
95
What are the typical animals of Tropical Rainforests?
Extremely diverse with vast numbers of spiders, insects, amphibians, reptiles, birds and mammals
96
What are the typical animals of Deserts?
Common desert animals include snakes and lizards, scorpions, ants, beetles, migratory and resident birds, and seed-eating rodents. Many species are nocturnal.
Water conservation is a common adaptation, with some species surviving solely on water from breaking down carbohydrates in seeds.
97
What are the typical animals of Savannah?
Large plant-eating mammals, such as wildebeests and zebras, and predators, including lions and hyenas, are common inhabitants.
The most prevalent herbivores are insects like ’termites’ and locusts.
98
What are the typical animals of Chaparral?
Mostly browsers, such as deer and goats, that feed on twigs and buds of woody vegetation
Also a high diversity of small mammals, amphibians, birds, reptiles and insects.
99
What are the typical animals of Temperate Grassland?
Native mammals include large grazers such as bison and wild horses.
Temperate grasslands are also inhabited by a wide variety of burrowing mammals, such as prairie dogs in North America.
100
What are the typical animals of Northern Coniferous Forests?
Many migratory birds nest in northern coniferous forests, other species reside there year-round. Also includes mammals such as moose, brown bears, and Siberian tigers.
Periodic outbreaks of insects that feed on the dominant trees can kill vast tracts of trees.
101
What is a sub biome of tropical rainforest and how does it differ?
’Tropical dry forest’ in which the precipitation is slightly less but more seasonal with a 6-moth dry season.
102
Why are deserts typically cold at night?
They are far from the sea which acts has a large SHC so warms the land during the night.
103
What are non-woody, non-grass plants grouped as?
‘Forbs'
104
What does ‘Forbs’ refer to?
Non-woody plants which aren’t grasses.
105
In what biome is plant diversity greater: northern coniferous forests or temperate broadleaf?
Temperate Broadleaf
106
What is the advantage of the conical shapes of pine cones?
They prevent snow from building up.
107
Why do pine tress have needles?
They reduce water loss and prevent snow from piling up.
108
What terrestrial ecosystem has the greatest animal diversity?
Tropical rainforest.
109
What is the typical temperature of Temperate broadleaf forests?
Winter temperatures average around 0°C.
Summers are hot and humid at up to 35ºC
110
What is the typical temperature of Tundra?
Winters are cold, with averages in some areas below –30°C.
Summer temperatures generally average less than 10°C.
111
What is the typical precipitation of Temperate broadleaf forests?
Precipitation can average from about 70 to over 200 cm annually.
Significant amounts fall during all seasons, including summer rain and, in some forests, winter snow.
112
What is the typical precipitation of Tundra?
Precipitation averages from 20 to 60 cm annually in arctic tundra but may exceed 100 cm in alpine tundra.
113
What is a sub biome of Tundra?
Alpine tundra which is found on the side of mountains
114
What are the typical animals of Tundra?
Large grazing musk oxen are resident, while caribou and reindeer are migratory. Predators include bears, wolves, and foxes.
Many bird species migrate to the tundra for summer nesting.
115
What are the typical animals of Temperate Broadleaf Forests?
In the Northern Hemisphere, many mammals hibernate in winter, while many bird species migrate to warmer climates.
Mammals, birds, and insects make use of all the vertical layers of the forest.
116
Besides rainforests, what biomes have multiple layer?
All forest biomes
117
What are the typical plants of Temperate Broadleaf Forests?
mature temperate broadleaf forest has distinct
vertical layers, including a closed canopy, one or two strata of understory trees, a shrub layer, and an herb layer.
There are few epiphytes. The dominant plants in the Northern Hemisphere are deciduous trees, which drop their leaves before winter, when low temperatures would reduce photosynthesis and make water uptake from frozen soil difficult.
In Australia, evergreen eucalyptus trees dominate these forests.
118
What are the typical plants of Tundra?
The vegetation of tundra is mostly herbaceous, consisting of a mixture of mosses,
grasses, and forbs, along with some dwarf shrubs and trees and lichens.
A permanently frozen layer of soil called permafrost restricts the growth of plant roots.
119
What does 'permafrost’ refer to?
A permanently frozen layer of soil
120
What is a permanently frozen layer of soil called?
Permafrost
121
What is an important property aquatic environments?
They have zones
122
What are the zones in lake?
It has a ‘littoral zone’ which consists of the extremely shallow water. The rest of the water is in the ‘limnetic zone’
The top of the water is called the ‘photic zone’ as it can be reached by sunlight. The ‘aphasic zone’ below cannot be.
They water around the bottom of the lake is the ‘benthic zone’. The rest is the ‘pelagic zone’
Note that these zones are not mutual exclusive i.e ash organism can be in the photic zone and the limnetic zone simultaneously.
123
What are the zones in the ocean?
It has a ’neritic’ which consists of the extremely shallow water. The rest of the water is in the ‘oceanic zone’
It has a ‘intertidal zone’ which is covered by water or not depending on the tide.
The top of the water is called the ‘photic zone’ as it can be reached by sunlight. The ‘aphasic zone’ below cannot be.
They water around the bottom of the lake is the ‘benthic zone’. The rest is the ‘pelagic zone’ if it is above 6000m or the ‘abyssal zone’ if it is below.
124
What are the organisms which live in the benthic zone called?
The ‘Benthos'
125
What does ‘benthos’ refer to?
The organisms that live in the benthic zone.
126
What are the conditions in the photic zone?
- High sunlight
- High oxygen
- Relatively low detritus except in the Benthic zone
127
What are the conditions of the benthic zone?
- Low sunlight
- Low oxygen
- Relatively low detritus except in the Benthic zone
128
How does the temperature of a lake vary as the depth increases?
It is warm at the surface and drops suddenly below the photic zone. This sudden drop is called the ’thermocline'
129
What dose ’thermocline’ refer to?
The sudden drop in temperature seen in lakes as depth increases.
130
What is a major source of food for the ‘benthos’?
Detritus
131
What is a major consequence of the ’thermocline’?
It leads to ’seasonal turnover'
132
What is ’seasonal turnover’?
The seasonal movement of water between the layers of the lake.
133
Why is seasonal turnover important?
By tuning over the water it provides oxygenated water to the bottom of the lake and brings up nutrient rich detritus to the surface from the benthic zone.
134
How does ’seasonal turnover’ occur?
In winter, the coldest water in the lake (0°C) lies just below the surface ice; water becomes progressively warmer at deeper levels of the lake, typically 4°C at the bottom.
In spring, as the ice melts, the surface water warms to 4°C and mixes with the formerly cooler layers below, eliminating thermal stratification. Spring winds help mix the water, bringing oxygen to the bottom waters and nutrients to the surface.
In summer, the lake regains a distinctive thermal profile, with warm surface water separated from cold bottom water by a narrow vertical zone of abrupt temperature change, called a thermocline.
In autumn, as surface water cools rapidly, it sinks beneath the underlying layers, remixing the water until the surface begins to freeze and the winter temperature profile is reestablished.
135
What are the major aquatic biomes?
Lakes, Wetlands, Streams/Rivers, Estuaries, Intertidal Zones, Oceanic Pelagic Zone, Coral Reefs and Marine Benthic zone.
136
What is the physical environment of lakes?
Standing bodies of water range from ponds a few square meters in area to lakes covering thousands of square kilometers. Light decreases with depth, creating stratification.
Temperate lakes may have a seasonal thermocline; tropical lowland lakes have a thermocline year-round.
137
What is the physical environment of wetlands?
A wetland is a habitat that is inundated by water at least some of the time and that supports plants adapted to water-saturated soil. Some wetlands are inundated at all times, whereas others flood infrequently.
138
What is the physical environment of streams/rivers?
The main characteristic of streams and rivers is their current. Headwater streams are generally cold, clear, turbulent and swift.
Farther downstream, where numerous tributaries may have joined, forming a river, the water is generally warmer and more turbid because of suspended sediment.
Streams and rivers are stratified into vertical zones.
139
What is the physical environment of estuaries?
They are a transition area between river and sea. Seawater flows up the estuary channel during a rising tide and flows back down during the falling tide.
Often, higher-density sea-water occupies the bottom of the channel and mixes little with the lower-density river water at the surface.
140
What is the physical environment of intertidal zones?
An intertidal zone is periodically submerged and exposed by the tides, twice daily on most marine shores.
Upper zones experience longer exposures to air and greater variations in temperature and salinity.
Changes in physical conditions from the upper to the lower intertidal zones limit the distributions of many organisms to particular strata.
141
What is the physical environment of oceanic pelagic zones?
The oceanic pelagic zone is a vast realm of open blue water, constantly mixed by wind-driven oceanic currents. Because of higher water clarity, the photic zone extends to greater depths than in coastal marine waters.
142
What is the physical environment of coral reefs?
Coral reefs are formed largely from the calcium carbonate skeletons of corals. Shallow reef building corals live in the photic zone of relatively stable tropical marine environments with high water clarity, primarily on islands and along the edge of some continents.
They are sensitive to temperatures below about 18–20°C and above 30°C. Deep-sea coral reefs, found between 200 and 1,500 m deep, are less known than their shallow counterparts but harbor as much diversity as many shallow reefs do.
143
What is the physical environment of marine benthic zones?
The marine benthic zone consists of the seafloor below the surface waters of the coastal, or neritic, zone and the off-shore, pelagic zone. Except for shallow, near-coastal areas, the marine benthic zone receives no sunlight.
Water temperature declines with depth, while pressure increases. As a result, organisms in the very deep benthic, or abyssal, zone are adapted to continuous cold (about 3°C) and very high water pressure.
144
What is the chemical environment of lakes?
The salinity, oxygen concentration, and nutrient content differ greatly among lakes and can vary with season. Oligotrophic lakes are nutrient-poor
and generally oxygen-rich; eutrophic lakes are nutrient-rich and often depleted of oxygen in the deepest zone in summer and if covered with ice in winter.
The amount of decomposable organic matter in bottom sediments is low in oligotrophic lakes and high in eutrophic lakes; high rates of decomposition in deeper layers of eutrophic lakes cause periodic oxygen depletion.
145
What is the chemical environment of wetlands?
Because of high organic production by plants and decomposition by microbes and other organisms, both the water and the soils are periodically low in dissolved oxygen.
Wetlands have a high capacity to filter dissolved nutrients and chemical pollutants.
146
What is the chemical environment of streams/rivers?
The salt and nutrient content of streams and rivers increases from the headwaters to the mouth.
Headwaters are generally rich in oxygen. Downstream water may also contain substantial oxygen, except where there has been organic enrichment.
A large fraction of the organic matter in rivers consists of dissolved or highly fragmented material that is carried by the current from forested streams.
147
What is the chemical environment of estuaries?
Salinity varies spatially within estuaries, from nearly that of fresh water to that of seawater. Salinity also varies with the rise and fall of the tides.
Nutrients from the river make estuaries, like wetlands, among the most productive biomes.
148
What is the chemical environment of intertidal zones?
Oxygen and nutrient levels are generally high and are renewed with each turn of the tides.
149
What is the chemical environment of oceanic pelagic zones?
Oxygen levels are generally high. Nutrient concentrations are generally lower than in coastal waters.
Because they are thermally stratified year-round, some tropical areas of the oceanic pelagic zone have lower nutrient concentrations than temperate oceans. Turnover between fall and spring renews nutrients in the photic zones of temperate and high-latitude ocean areas.
150
What is the chemical environment of coral reefs?
Corals require high oxygen levels and are excluded by high inputs of fresh water and nutrients.
151
What is the chemical environment of marine benthic zones?
Except in areas of organic enrichment, oxygen is usually present at sufficient concentrations to support diverse animal life.
152
What are the geologic features of lakes?
Oligotrophic lakes may become more eutrophic over time as runoff adds sediments and nutrients.
They tend to have less surface area relative to their depth than eutrophic lakes.
153
What are the geologic features of wetlands?
'Basin' wetlands develop in shallow basins, ranging from upland depressions to filled-in lakes and ponds.
‘Riverine' wetlands develop along shallow and periodically flooded banks of rivers and streams.
‘Fringe' wetlands occur along the coasts of large lakes and seas, where water flows back and forth because of rising lake levels or tidal action. Thus, fringe wetlands include both freshwater and marine biomes.
154
What are the geologic features of streams/rivers?
Headwater stream channels are often narrow, have a rocky bottom, and alternate between shallow sections and deeper pools.
The downstream stretches of rivers are generally wide and meandering.
River bottoms are often silty from sediments deposited over long periods of time.
155
What are the geologic features of estuaries?
Estuarine flow patterns combined with the sediments carried by river and tidal waters create a complex network of tidal channels, islands, natural levees, and mudflats.
156
What are the geologic features of intertidal zones?
The substrates of intertidal zones, which are generally either rocky or sandy, select for particular behavior and anatomy among intertidal organisms.
The configuration of bays or coastlines influences the magnitude of tides and the relative exposure of intertidal organisms to wave action.
157
What are the geologic features of oceanic pelagic zones?
This biome covers approximately 70% of Earth’s surface and has an average depth of nearly 4,000 m. The deepest point in the ocean is more than 10,000 m beneath the surface.
158
What are the geologic features of coral reefs?
Corals require a solid substrate for attachment.
A typical coral reef begins as a 'fringing reef' on a young, high island, forming an offshore 'barrier reef' later in the history of the island and becoming a 'coral atoll' as the older island submerges.
159
What are the geologic features of marine benthic zones?
Soft sediments cover most of the benthic zone. However, there are areas of rocky substrate on reefs, submarine mountains, and new oceanic crust.
160
What are the autotrophs of lakes?
Rooted and floating aquatic plants live in the 'littoral zone', the shallow, well-lit waters close to shore.
Farther from shore, where water is too deep to support rooted aquatic plants, the 'limnetic zone' is inhabited by a variety of phytoplankton, including cyanobacteria.
161
What are the autotrophs of wetlands?
Wetlands are among the most productive biomes on Earth.
Their water-saturated soils favor the growth of plants such as floating pond lilies and emergent cattails, many sedges, tamarack, and black spruce, which have adaptations enabling them to grow in water or in soil that is periodically anaerobic owing to the presence of unaerated water.
Woody plants dominate the vegetation of swamps, while bogs are dominated by sphagnum mosses.
162
What are the autotrophs of streams/rivers?
Headwater streams that flow through grasslands or deserts may be rich in phytoplankton or rooted aquatic plants.
163
What are the autotrophs of estuaries?
Saltmarsh grasses and algae, including phytoplankton, are the major producers in estuaries.
164
What are the autotrophs of intertidal zones?
A high diversity and biomass of attached marine algae inhabit rocky intertidal zones, especially in the lower zone.
Sandy intertidal zones exposed to vigorous wave action generally lack attached plants or algae, while sandy intertidal zones in protected bays or lagoons often support rich beds of seagrass and algae.
165
What are the autotrophs of oceanic pelagic zones?
The dominant photosynthetic organisms are phytoplankton, including photosynthetic bacteria, that drift with the oceanic currents.
Spring turnover renews nutrients in temperate oceans producing a surge of phytoplankton growth.
Because of the large extent of this biome, photosynthetic plankton account for about half of the photosynthetic activity on Earth.
166
What are the autotrophs of coral reefs?
Unicellular algae live within the tissues of the corals, forming a mutualistic relationship that provides the corals with organic molecules.
Diverse multicellular red and green algae growing on the reef also contribute substantial amounts of photosynthesis.
167
What are the autotrophs of marine benthic zones?
Photo- synthetic organisms, mainly seaweeds and filamentous algae, are limited to shallow benthic areas with sufficient light to support them.
Unique assemblages of organisms are found near deep-sea hydrothermal vents on mid-ocean ridges.
In these dark, hot environments, the food producers are chemoautotrophic prokaryotes that obtain energy by oxidizing H2S formed by a reaction of the hot water with dissolved sulfate (SO42–).
168
What are the heterotrophs of lakes?
In the limnetic zone, small drifting heterotrophs, or zooplankton, graze on the phytoplankton.
The benthic zone is inhabited by assorted invertebrates whose species composition depends partly on oxygen levels.
Fishes live in all zones with sufficient oxygen.
169
What are the heterotrophs of wetlands?
Wetlands are home to a diverse community of invertebrates, birds, and many other organisms.
Herbivores, from crustaceans and aquatic insect larvae to muskrats, consume algae, detritus, and plants.
Carnivores are also varied and may include dragonflies, otters, frogs, alligators, and herons.
170
What are the heterotrophs of streams/rivers?
A great diversity of fishes and invertebrates inhabit unpolluted rivers and streams, distributed according to, and throughout, the vertical zones.
In streams flowing through temperate or tropical forests, organic matter from terrestrial vegetation is the primary source of food for aquatic consumers.
171
What are the heterotrophs of estuaries?
Estuaries support an abundance of worms, oysters, crabs, and many fish species that humans consume.
Many marine invertebrates and fishes use estuaries as a breeding ground or migrate through them to freshwater habitats upstream.
Estuaries are also crucial feeding areas for waterfowl and some marine mammals.
172
What are the heterotrophs of intertidal zones?
Many of the animals in rocky intertidal environments have structural adaptations that enable them to attach to the hard substrate.
The composition, density, and diversity of animals change markedly from the upper to the lower intertidal zones.
Many of the animals in sandy or muddy intertidal zones, such as worms, clams, and predatory crustaceans, bury themselves and feed as the tides bring sources of food. Other common animals are sponges, sea anemones, echinoderms, and small fishes.
173
What are the heterotrophs of oceanic pelagic zones?
The most abundant heterotrophs in this biome are zooplankton. These protists, worms, copepods, shrimp-like krill, jellies, and small larvae of invertebrates and fishes graze on photosynthetic plankton.
The oceanic pelagic zone also includes free-swimming animals, such as large squids, fishes, sea turtles, and marine mammals.
174
What are the heterotrophs of coral reefs?
Corals, a diverse group of cnidarians, are themselves the predominant animals on coral reefs.
However, fish and invertebrate diversity is exceptionally high. Overall animal diversity on coral reefs rivals that of tropical forests.
175
What are the heterotrophs of marine benthic zones?
'Neritic benthic' communities include numerous invertebrates and fishes. Beyond the photic zone, most consumers depend entirely on organic matter raining down from above.
Among the animals of the deep-sea hydrothermal vent communities are giant tube worms, some more than 1 m long. They are nourished by chemoautotrophic prokaryotes that live as symbionts within their bodies.
Many other invertebrates, including arthropods and echinoderms, are also abundant around the hydrothermal vents.
176
What is the word for a nutrient poor region?
‘Oligotrophic'
177
What is the word for a nutrient rich region?
‘Eutrophic'
178
What does ‘Eutrophic’ refer to?
A nutrient rich region
179
What does ‘Oligotrophic’ refer to?
A nutrient poor region
180
What does 'gyre' refer to?
A circular current
