chapter4 Flashcards
Upwelling
A process in which deep, cold water rises toward the surface. Often this water carries large amounts of nutrients, leading to productive oceanic ecosystems
Thermocline
An abrupt temperature gradient in a body of water such as a lake, marked by a layer above and below which the water is at different temperatures
Gyres
Ocean ____________ are large system of circular ocean currents formed by global wind patterns and forces created by Earth’s rotation
Estuary
The tidal mouth of a large river, where the tide meets the stream
Coriolis effect
The effect of the earth’s turning on the direction of the wind, which is to the right in the northern hemisphere and to the left in the southern hemisphere
Riparian
A ___________ tree is a tree that is adapted to growth along the banks of a stream.
tundra
The biome that occurs around the Arctic circle, characterized by lichens, mosses, sedges, and dwarf trees.
Rainshadow
A region in the lee of mountains that receives less rainfall than the region windward of the mountains
Intertidal
The _________ zone is the part of the shoreline that is submerged at high tide but exposed to air at low tide
Biome
One of the major categories of the world’s distinctive plant assemblages, e.g. the tundra or the tropical rainforest
Savanna
The tropical grassland biome
Climate
The weather conditions prevailing in an area in general or over a long period
Taiga
The coniferous forest that extends across much of North America and Eurasia bounded by tundra to the North and by steppe to the south.
Stratification
The development of relatively stable light and warm layers above colder deeper layers within a body of water
Desert
A desolate and barren region, usually deficient in available water, and with scant vegetation
Boreal forest
Another word for taiga
Solstice
The time or date (twice each year) at which the sun reaches its maximum or minimum declination, marked by the longest and shortest days (about 21 June and 22 December).
Polar cell
Atmospheric circulation cell located at roughly 60 to 90° North and South of the equator.
Permafrost
Layer of permanently frozen soil.
Weather
The state of the atmosphere at a particular place and time as regards heat, cloudiness, dryness, sunshine, wind, rain, etc
Equator
A line notionally drawn on the earth equidistant from the poles, dividing the earth into northern and southern hemispheres and constituting the parallel of latitude 0°
Epiphyte
A plant that grows on another plant, especially one that is not parasitic, such as the numerous ferns, bromeliads, air plants, and orchids growing on tree trunks in tropical rainforests.
Deadzone
An area of ocean floor where oxygen is depleted, and where fish and other animals can not survive.
Watershed
A land area where all the water draining from it comes to a particular stream or river
Hadley cell
A large-scale atmospheric convection cell in which air rises at the equator and sinks at medium latitudes, typically about 30° north or south.
Global climate patterns
Large scale climatic patterns are defined by:
Incident sunlight at different latitudes
Atmospheric circulation
Ocean currents
Land topography
Soil pH
Calcareous soil -> Calcicole flora
Suffer from aluminium or iron poisoning at low pH
Acidic soils -> Calcifuge flora
Suffer from nutrient deficiency at high pH
Soil organic matter
Soil organic matter is the living or dead plant and animal material in the soil
The imput and decomposition rate of organic matter may vary
-> Organic matter content of soils is variable
Hautes Fagnes, Belgium: decomposition is impeded due to anoxic conditions
Very high soil organic matter content (>30%)
Terrestrial biomes: classification
Biomes are areas dominated by plants with characteristic shapes, forms and physiology
Tropical rain forest
Characteristics of tropical rain forest trees:
straight trunks that don’t branch out for 30 meters or more
smooth, thin bark, because there is no need to protect the stem from water loss and freezing temperatures
Most productive systems in the world (>1000 g C/m2/y)
Highest biodiversity biome
90% of species in the upper canopy
Year-round growth and reproduction
Sunlight penetrates only through gaps in the dense canopy
Very little primary production on the soil
Savanna
Large influence of grazing herbivores
Fire
Seasonal rainfall
Seasonal rainfall: in drier years the large herbivores may be famished
Temperate grassland
Large areas of all continents
Seasonal rainfall
Large influence of grazing herbivores
Largely cultivated by humans
Desert
Unpredictable rainfall (<15 cm/y)
2 types of plants:
Fast-growing opportunists
Slow-growing tolerators
Low animal diversity
Temperate forest
Dominated by deciduous trees
Often a mixture of long-lived species and fast colonizers
Food resources limited during winter season
Northern coniferous forest (Taiga)
Limited tree flora (biomonotony)
Subject to diseases
Tundra
Low biodiversity
Short growing season
Little precipitation
Accumulation of dead organic matter
Aquatic environments
Properties of water:
Strong solvent
High thermal capacity
Viscous
Oxygen content decreases with increasing temperature
Streams
Streams are characterised by:
Linear form
Unidirectional flow
Fluctuating discharge
Unstable beds
Oxygen concentration: often higher in upstream areas
Active upstream fish species require more oxygen than slow downstream species
Riparian vegetation:
terrestrial vegetation surrounding a stream
May reduce primary production in the stream (by shading)
May provide an extra food source by shedding leaves
Lakes,Stratification:
Stratification: The formation of separate vertical water layers that differ in temperature and/or salinity
annual lake cycle
summer: stratified
fall: condition turnove
winter: stratified
spring: condition turnover
The oceans, Photic zone
Photic zone: the upper part of the ocean where net photosynthesis can take place
Availability of mineral nutrients determines variations in communities
the oceans, Marine desert
production in the open ocean <35 g C/m2/y
Compare rainforest: 1000 g C/m2/y
Coasts
Are dominated by tides and waves
Organisms in intertidal zones are subject to enormous fluctuations in conditions
tropical rainforest numbers
mean primary production per area (tonnes per km): 2200
Area (millions of km2): 17
mean global primary productivity(billions of tonnes):37.4
temperate deciduous forests numers
mean primary production per area (tonnes per km): 1200
Area (millions of km2): 7
mean global primary productivity(billions of tonnes): 8.4
Taiga numbers
mean primary production per area (tonnes per km): 800
Area (millions of km2): 12
mean global primary productivity(billions of tonnes): 9.6
temperate grassland numbers
mean primary production per area (tonnes per km): 600
Area (millions of km2): 9
mean global primary productivity(billions of tonnes): 5.4
desert numbers
mean primary production per area (tonnes per km): 90
Area (millions of km2): 18
mean global primary productivity(billions of tonnes): 1.6
cultivated land numbers
mean primary production per area (tonnes per km): 650
Area (millions of km2): 14
mean global primary productivity(billions of tonnes): 9.1
open oceans number
mean primary production per area (tonnes per km): 125
Area (millions of km2): 332
mean global primary productivity(billions of tonnes): 41.5
coral reefs and agal beds numbers
mean primary production per area (tonnes per km): 2500 (highest)
Area (millions of km2): 0.6
mean global primary productivity(billions of tonnes): 1.6
swamp and marsh
mean primary production per area (tonnes per km): 2000
Area (millions of km2): 2
mean global primary productivity(billions of tonnes): 4
