Climate and Biomes Flashcards
(117 cards)
1
Q
What two environmental factors significantly influence the speed of biological and chemical processes?
A
Temperature and precipitation
2
Q
What is Biomass?
A
Dry mass of an organism’s organic material
3
Q
What is Gross Primary Productivity (GPP)?
A
The amount of carbon assimilated into biomass, usually expressed over an area and time
4
Q
What is Net Primary Productivity (NPP)?
A
The rate at which an ecosystem’s producers capture and store energy as biomass, minus the energy they use for their own respiration.
5
Q
Are nutrient cycles considered closed systems?
A
Yes.
6
Q
What are nutrient cycles?
A
They describe how essential elements move and are reused within an ecosystem, flowing between living organisms and the non-living environment, ensuring these chemicals aren’t lost.
7
Q
What is the difference between an organic and an inorganic compound?
A
Organic compounds include hydrogen and carbon, whereas inorganic compounds don’t.
8
Q
What is the difference between a flux and a pool?
A
A pool is the quantity of nutrients in the compartment, whereas a flux is the movement of nutrients between compartments
9
Q
What is a cycle?
A
The interactions between pools and fluxes
10
Q
What are compartments?
A
The defined location where a nutrient resides.
11
Q
What is a wetland?
A
An ecosystem that arises when inundation by water produces soil dominated by anaerobic processes, which, in turn, forces the biota, particularly rooted plants, to adapt to flooding
12
Q
How much of the Earth’s land surface is wetland?
A
Approximately 6% (5.6 million km²)
13
Q
What are wetlands known for in terms of ecological output and species richness?
A
Being among the most productive ecosystems in the world and hotspots of biodiversity.
14
Q
What are the six types of wetlands?
A
*Swamp
*Bog
*Fen
*Wet meadow
*Marsh
*Shallow water (Mangroves)
15
Q
Characteristics of a Swamp.
A
Dominated by trees that are rooted in hydric soils (saturated with water), but not peat. Flood tolerance is the primary controlling factor of species composition
16
Q
Characteristics of a Bog
A
Dominated by Sphagnum moss, sedges, ericaceous shrubs, or evergreen trees rooted in deep peat with a pH <5 (Acidic), fed by rainwater
17
Q
Characteristics of a Fen
A
Dominated by sedges and grasses rooted in shallow peat, high groundwater movement, pH >6 (alkaline)
18
Q
Characteristics of a Wet Meadow
A
Dominated by herbaceous plants rooted in occasionally flooded soils, temporary flooding excludes terrestrial and swamp plants
19
Q
Characteristics of Marshes
A
Dominated by herbaceous plants that are usually emergent through water and rooted in hydric soils, but not peat. Frequent inundation requires tolerance of Anoxia, herbivory, and fire, mechanical disturbance (e.g., waves), and woody shoots are not suitable!
20
Q
Characteristics of Mangroves
A
Dominated by truly aquatic plants growing in and covered by at least 25cm of water
21
Q
What is Anoxia?
A
The complete absence of oxygen in their tissues
22
Q
What are the four main wetland positions?
A
*Limnogenous: occurring beside lakes and rivers
*Topogenous: occurring in depressions and valleys
*Ombrogenous: Peat has accumulated above the land surface
*Soligenous: occurring on sloped land
23
Q
What are the main impacts of human activity on wetlands?
A
*Abandonment
*Conversion: Eg. Drainage, dams, Grazing
*Pollution: Eg, Eutrophication
24
Q
What other threats do wetlands face?
A
*Invasive species: usually exotic, often exist in the seed bank, are better adapted to a range of conditions, allowing dominance of the ecosystem
*Grazing and overgrazing
25
What percentage of the world's land surface do grasslands cover?
Approximately 20%
26
What percentage of the total global biosphere carbon store is found in grasslands?
10% of the total global biosphere carbon store. Up to 98% of this carbon is sequestered below ground.
27
Why are soils in North Wales described as being better for grass than crops?
Due to their clay content.
28
Name the provisioning services provided by grassland ecosystems.
*Food
*water
*minerals
*pharmaceuticals
*biochemical products
*industrial products
*energy (hydropower, biomass fuels)
29
Name the regulating services provided by grassland ecosystems.
*Carbon sequestration
*climate regulation
*waste decomposition
*detoxification
*purification of water and air
*water quantity
*crop pollination
*pest and disease control
30
Name the supporting services provided by grassland ecosystems.
*Nutrient dispersal and cycling
*seed dispersal
*primary production
31
Name the cultural services provided by grassland ecosystems.
*Cultural & spiritual inspiration
*recreational experiences
*scientific discovery
32
What are the typical soil types found in lowland grasslands in the UK?
Brown earth and gley soils.
33
What are the typical soil types found in upland grasslands in the UK?
Podzol and peat soil.
34
Describe ways in which human actions act as ecosystem drivers in grasslands.
*Cleared forests
*drained land
*ploughed and reseeded
*planted specific species (perennial ryegrass and clover)
*added fertilisers
*added lime
35
Describe ways in which managed animals (like cattle and sheep) act as ecosystem drivers in grasslands.
*Maintain the grass sward
*prevent tree re-growth (tree seedlings eaten, reduced seed bank in the soil)
*add dung and urine
*compaction
*Stimulate root turnover
36
What are the three classifications of earthworms found in grassland soils?
*Epigeic: Litter dwelling (e.g., Eisenia fetida)
*Endogenic: Shallow living (e.g., Aporrectodea rosea)
*Anecic: Deep burrowing (e.g., Lumbricus terrestris)
37
What is a key characteristic that allows grasses to grow back after being grazed or cut? W
They grow back from the base due to the intercalary meristem.
38
Describe the symbiotic relationship between grasses and Arbuscular mycorrhizal fungi.
The plant gives the mycorrhiza carbon (C), and the mycorrhiza gives the plant phosphorus (P) in return.
39
What is the symbiotic relationship between clover and Rhizobia bacteria?
Clover has a symbiosis with nitrogen-fixing Rhizobia bacteria. This process can fix nitrogen (N), providing a crucial nutrient for grass growth.
40
Describe two characteristics of grassland soils related to root and mycorrhizal hyphal density.
*Incredibly high root density (1 m of root per gram of soil)
*Incredibly high mycorrhizal hyphal density (1 km per gram of soil)
41
Name the ways carbon enters grassland soils and the ways it leaves.
*Enters: Litter, Root turnover, Microbial turnover, Faeces from grazing animals, livestock manures, composts, biosolids, digestate
*Leaves: Microbial breakdown to CO₂, CH₄, erosion, DOC leaching
42
At what temperature does grass typically start to grow?
7-8°C
43
Name the adaptations of grasses to cold stress.
*Produce cryoprotectants/antifreeze proteins
*change in membrane lipid composition
*increase soluble sugars in the cells to lower the freezing point
44
Name the adaptations of grasses to drought conditions.
*Deeper roots
*roots that release mucilage into the soil to increase soil-root contact
*Mycorrhizas that may transport water to the plant
*hydraulic lift
*increase in osmolytes in cells
45
Name the adaptations of grasses to excessive water
*Shallower roots
*Aerenchyma formation in roots
*excrete toxic products from respiration into the rhizosphere
46
What is a consequence of soil compaction in grasslands?
It makes it harder for roots to get water, nutrients, and oxygen.
47
What is a major consequence of overgrazing in grasslands?
Exposure of soil, which is prone to soil erosion, leads to the loss of topsoil and nutrients.
48
What are the typical annual requirements for Nitrogen (N), Potassium (K), and Phosphorus (P) fertilizer in productive grasslands (in kg/ha/y)?
Nitrogen (N): 150 kg N/ha/y
Potassium (K): 80 kg K/ha/y
Phosphorus (P): 30 kg P/ha/y
49
What visible symptom might indicate nitrogen deficiency in grassland plants?
Yellowing leaves, because nitrogen is needed for the formation of chlorophyll
50
What visible symptom might indicate phosphorus deficiency in grassland plants?
Pink colour in leaves, because phosphorus is needed for DNA and phospholipid formation, which are essential for cell growth.
51
Why is low soil pH (<5.0) a stress for grassland plants?
Low soil pH leads to poor nutrient availability and the increased solubility of Aluminium (Al³⁺), which is toxic to roots.
52
Name the adaptations of grasses to acidic soil conditions.
*Release OH⁻ ions from roots
*release organic acids to bind Al³⁺
*make it non-toxic
53
Name the types of pathogens that can affect grassland plants.
*Fungi on the leaves (e.g., rusts)
*aphids on leaves and roots
*insect larvae on roots (e.g., leatherjackets)
54
What are the potential consequences of fire in grassland ecosystems?
Loss of carbon (C), nitrogen (N), and sulfur (S) when grass burns.
55
Name the adaptations of plants found in maritime grasslands to cope with salinity stress.
*Excluding salt at the plant surface
*Removing salt from cytoplasmic vacuoles
56
Name the top six pollutants from UK grasslands.
Nitrate, Phosphate, Nitrous oxide, Methane, Human pathogens, Endocrine-disrupting chemicals.
57
What is a major environmental concern associated with nitrate and phosphate pollution from grasslands?
Contamination of surface and groundwater, eutrophication, potential link to cancer if high in drinking water.
58
How can the risk of nitrate and phosphate pollution from grasslands be minimised?
Do not apply as much fertiliser, add slow-release fertilisers, only add them during the growing season, match demand with supply, use more nutrient-efficient grasses, and the ‘four R’s’ = right rate, time, place, and form
59
What are the two main processes in the nitrogen cycle that can lead to nitrous oxide?
*Nitrification (Aerobic conditions)
*Denitrification (Anaerobic conditions)
60
How can the risk of nitrous oxide (N2O) pollution from grasslands be minimised?
Use less fertiliser (use clover instead), add slow-release fertilisers, nitrification inhibitors, only add fertiliser during the growing season, increase drainage to increase soil aeration, manage sources of nitrogen (fertilizer, manure, urine/dung, OM mineralisation)
61
Under what soil conditions is methane (CH4) typically produced?
Methane is produced under anoxic (oxygen-deficient) conditions. Main sources are ruminants, manure, and soils.
62
How can the risk of methane (CH4) pollution from grasslands be minimised?
Change the gut flora of ruminants, improve ruminant diets, keep livestock healthy, improve efficiency of production, anaerobic digestion of manures, increase drainage to increase soil aeration
63
Name one example of a human pathogen that can be released in a grazer's faeces.
Examples: E. coli O157, Cryptosporidium, Salmonella (any one of these).
Potential consequences: Shellfish and drinking water contamination.
64
How can the risk of human pathogen pollution from grazing livestock be minimised?
Provide animal vaccines, prevent cattle from being near water supplies, do not apply organic manure when there is a risk of surface runoff, or within 10m of a watercourse
65
What are the endocrine-disrupting chemicals mentioned as pollutants from grazing livestock?
Estrogen and estrone. Freshwater contamination is potentially affecting fish reproduction.
66
How can the risk of endocrine-disrupting chemical pollution from grazing livestock be minimised?
Prevent animals from being near water supplies, and reduce animal density on fields
67
What is peat?
Peat is partially decayed plant material accumulating under water-logged conditions, generally high in organic matter. A soil is typically classified as peat (an ‘organic soil’ or histosol) if it has anything above 20% organic matter (or 12% carbon).
68
What is the typical rate of peat accumulation per year?
Approximately 1 mm per year.
69
Why are peatlands considered the most carbon-dense ecosystems on Earth?
Due to the waterlogged conditions that slow down the decomposition of plant material, leading to a high accumulation of organic carbon.
70
What percentage of the world's land surface do peatlands cover, and what proportion of global soil carbon do they store?
Peatlands cover around 3% of the world’s land surface and store around 40% of the global soil carbon.
71
What percentage of the UK land area is covered by peat?
Peat covers 12% of the UK land area, and these peatlands store 30% of the UK’s total terrestrial carbon.
72
What percentage of the UK's peatlands are considered to be in 'natural' condition?
Only 22%
73
Name three different types of peatlands found worldwide and give a typical depth range for each.
*Fens: 0.5 to 2 meters (Minerotrophic)
*Bogs: 1 to 5 meters (Ombrotrophic)
*Tropical peat swamps: often 3 to 10 meters (can exceed 12 meters)
74
What is the primary water source for ombrotrophic peatlands?
Rainfall. They are typically acidic.
75
What is the primary water source for rheotrophic peatlands?
Surface runoff.
76
What is the primary water source for minerotrophic peatlands? How does this influence their acidity?
Groundwater. The base cations in the groundwater neutralise the acidity caused by peat-forming processes.
77
Name provisioning ecosystem services provided by peatlands.
*Fuel
*horticultural products
*water storage
*other products (e.g., genetic diversity)
78
Name regulating ecosystem services provided by peatlands.
*Carbon storage
*greenhouse gas regulation
*climate regulation
*water purification
*flood regulation (absorbs rain)
79
What is a key supporting ecosystem service provided by peatlands?
Biodiversity habitat
80
Name the cultural ecosystem services associated with peatlands.
*Recreation and tourism
*grouse shooting
*education and discovery
81
What are the threats that peatlands face?
*Physical removal
*land use change
*nitrogen deposition
*drainage
*climate change
*fire
82
Describe local mitigation strategies for peatland degradation.
*Restoration projects (re-wetting degraded peatlands, peatland management practices to increase biodiversity)
*Sustainable land management (adoption of sustainable agricultural practices, regenerative agriculture to reduce nutrient runoff, improved forestry practices)
*Community engagement (involvement of local communities, education on the value of peatlands)
83
What is paludification?
The process by which terrestrial ecosystems, such as forests or grasslands, become waterlogged and transform into wetlands, often leading to peat formation.
84
What is terrestrialisation?
The ecological process by which aquatic ecosystems gradually transition into terrestrial ones over time.
85
Name three key environmental characteristics that all polar organisms must survive.
Extreme seasonality, low solar radiation, and high albedo.
86
What is albedo?
How much light that hits a surface is reflected without being absorbed
87
How does solar radiation at the North Pole compare to that at the equator?
Solar radiation at the North Pole is only 43% of that at the equator
88
Why does the South Pole receive more solar radiation in summer than the North Pole?
Due to clearer skies and its closer proximity to the sun during its summer
89
How does the high albedo of snow and ice affect solar radiation in polar regions?
It leads to the reflection of a significant amount of solar radiation.
90
Name three principal environmental challenges faced by organisms in polar ecosystems.
Cold, desiccation, and radiation
91
Describe two physiological challenges that cold temperatures pose to organisms.
*Reduced enzyme activity
*Decreased membrane fluidity
*Impaired transcription and translation
*Altered nutrient transport
*Protein misfolding
92
What is the lower temperature limit for the functioning of many organisms, although they may survive much colder temperatures?
A lower functioning limit is around -20 °C. They may survive temperatures as low as -80 °C.
93
Name two physiological adaptations that polar organisms have to deal with cold temperatures.
*Production of more or different enzymes (e.g., higher Rubisco in Arctic plants)
*Ice-structuring proteins
*Cryoprotectants (e.g., carbohydrates, amino acids, methylamines)
*More unsaturated lipids in membranes.
94
How can cryoprotectants help organisms survive cold temperatures?
Cryoprotectants lower the freezing point of cellular fluids, preventing intracellular ice formation. Examples include carbohydrates, amino acids, and methylamines.
95
Describe two morphological adaptations that animals in polar regions have for conserving heat.
Thick coats and compact bodies (reducing surface area to volume ratio).
96
What is a morphological adaptation that some polar plants have to deal with cold?
Cushion-shaped growth.
97
Name four cold avoidance strategies used by polar organisms.
Hiding, hibernation, migration, and resting stages.
98
Why is desiccation a significant stressor in many polar regions despite the presence of ice and snow?
Precipitation can be very low, and most of the water is in a frozen state, making it unavailable as liquid water for biological processes and leading to slow microbial activity.
99
Name two strategies that polar organisms use to deal with desiccation, similar to their adaptations to cold.
Production of osmolytes (e.g., glycerol) or coating of microbial cells to prevent total drying, and tolerance of drying.
100
Describe two morphological adaptations that some polar plants have to deal with desiccation.
Thick leaves and thick cuticles.
101
What is the key difference between the Arctic and Antarctic regions regarding the movement of organisms?
The Arctic has land bridges allowing organisms to move into and out of the polar region. Antarctica has been isolated by the ocean and strong circumpolar currents and winds for millions of years.
102
Name the main primary producers in polar ecosystems.
Lichens, algae, bryophytes, and higher plants.
103
Where are the majority of the herbivores found in polar regions?
The majority of herbivores are found in the Arctic. There are no real grazers of larger plants in the Antarctic, only detritivores.
104
What is the size of the largest terrestrial predator in Antarctica?
The largest terrestrial predator in Antarctica is 1 mm long (Alaskozetes antarcticus). The largest terrestrial predator in the Arctic is the polar bear (Ursus maritimus), which is 2-3 m long.
105
Why are many marine mammals and flightless birds able to breed ashore in the Antarctic?
Due to the lack of land predators.
106
What is a major source of nutrients for the maritime Antarctic?
Marine animals are the largest input of nutrients (e.g., nitrogen) to many areas of the maritime Antarctic.
107
What types of macroscopic organisms are typically found in the harsher, ice-free areas away from the coasts in the southern Antarctic?
In the south, mainly microbes and lichens, perhaps some moss. In the north, there may be more mosses and some vascular plants.
108
What percentage of global freshwater is stored in the Greenland and Antarctic ice caps?
90%
109
Where do algae on glaciers typically grow, and what colors can they be?
It grows in films of unfrozen water on the surface of glaciers, generally in summer. It can be red, green, and sometimes yellow.
110
What are cryoconites?
Cryoconites are a mixture of dust and debris on glaciers. Their dark color absorbs energy, melting holes in the glacier. They also provide a habitat for heterotrophs (fungi, bacteria) that utilize carbon fixed by algae.
111
What type of microbes were found in the water and sediment of sub-glacial Lake Whillans?
Chemoautotrophs.
112
What was controversial about the bacteria found in Lake Vostok?
Their DNA was only 86% similar to known bacteria. It was claimed that this could be contamination from drilling fluid.
113
Where is the hypersaline sub-glacial lake known as "Blood Falls" located?
It is located in Antarctica. The red color is caused by the oxidation of dissolved Fe²⁺ to Fe³⁺ when the iron-rich water reaches atmospheric oxygen.
114
How long ago was the hypersaline sub-glacial lake that feeds "Blood Falls" cut off from the Southern Ocean?
2 million years ago. It has no light and no oxygen.
115
What is the primary energy source for the microbes found in the anoxic, hypersaline sub-glacial lake that feeds "Blood Falls"?
Chemoautotrophs that use sulfate (SO2−) and iron(III) (Fe3+) reduction to utilize trapped carbon. The oxidation of iron(II) (Fe2+) to iron(III) (Fe3+) when exposed to oxygen contributes to the red color.
116
What international treaty protects Antarctica south of 60°S?
The International Antarctic Treaty. It came into force in 1961. It designates Antarctica as a natural reserve devoted to peace and science, and prohibits mining.
117
What activity is already taking place in the sub-Antarctic?
Oil prospecting is already taking place in the sub-Antarctic.
