Flashcards

Environmental Ecology

Alisa C Biology Degree English 190 cards

Describe and explain the graph of annual precipitation against annual temperature

Cards in this deck (190)

1What is the difference between climate change and environmental change?Climate change - a change in the chemical and physical properties of the climate system considered over longer periods, regardless of cause.
Environmental change- also includes biogeochemical changes, including biodiversity, anthropogenic influences and land use aspects.
2Describe and explain the graph of annual precipitation against annual temperature
3What are peatlands and what problems do they pose?Peatlands are boggy land. People dug through them to try to make them better for agriculture, so now they are draining. this means they can't survive, which impacts the climate. It takes a very long time for peat to grow, so reforming is not a viable option.
4What is the Earth's energy budget?How much energy comes into the Earth's climate system from the Sun, how much energy is reflected back into space, and how much remains on Earth and in its atmosphere.
5Diagram for Earth's energy budget?
6Why do we live in a steady state here on Earth?Because the energy coming in from the sun is roughly equal to that leaving from Earth.
7What is the energy budget equation?S= solar radiation
σ is a constant
πR^2= area of a disk
4πR^2= area of a sphere
Term on the right- how much energy was absorbed by the Earth
This is the equation without an atmosphere- with is much warmer
8What is the difference between short and long wave forcingShort wave is the energy coming from the sun and at a higher energy (hotter) and comes from the sun
Long wave is at a lower energy and comes from Earth
9What is the Earth's radioactive budget?The balance between incoming energy from the sun and the outgoing long wave and reflected shortwave energy from the Earth.
10Why do different zones on Earth have different levels of insulation?Because sun beams hit Earth at different angles. This changes the amount of energy received by that zone, affecting the heat and behaviour of that zone.
11What is energy measured in?Watts per square meter
12Diagram of the energy budget with an atmosphere
13What controls long wave forcing?Greenhouse gases. A greenhouse gas is any gas that can absorb light in the infra-red and microwave wavelengths.
14Which greenhouse gases make up the atmosphere and in what amounts? (ppmv= parts per million by volume)
15What are the effectiveness' of the greenhouse gases?Water is most effective as it can absorb most energy, but it has almost reached complete absorption so won't absorb much more radiation in the atmosphere if more is added. Oxygen, ozone and CO2 have space for more absorption, so adding them will increase greenhouse effect on Earth. Nitrous oxide is the most effective greenhouse gas, but is much less concentrated.
16What mainly controls short wave forcing?Solar system cycles (Milankovitch cycles)
17What has a small control over shortwave forcing?Sunspots. The variation caused by the sunspot cycle to solar output is relatively small, around 0.1% of the solar constant. With climate feedbacks this may have played an important role pre-industrial era into as late as the 1900s.
18Why is surface albedo different for different vegetation types?Complexity of the surface can change how the Earth responds- snow falls flat on croplands and grassland, reflecting the energy. Forests do not have the flat surface, so less energy will be reflected.
19What can affect albedo?-Temporal heterogeneity
- Spacial heterogeneity
- Nutrient status
20What is neither short nor long radiative forcing?Aerosol. Aerosol particles reflect or absorb solar radiation.
21What are the effects of volcanic eruption on aerosol forcing?After a volcanic eruption, the increased sulphuric acid particles cool the atmosphere.
22The whole picture of short and long wave forcing
23Why is the energy received directly better absorbed by the Earth's surface?Because the sun's rays have to travel through the thinnest amount of atmosphere, so only a small amount is absorbed by it and the rest by Earth.
24What is atmospheric circulation?The large-scale movement of air by which thermal energy is distributed on the surface of the Earth.
25What does the Coriolis Effect do?Causes water and air to curve as they move across or above the Earth's surface. At the equator, the Earth spins from west to east faster than at the poles.
26What and where are the three wind belts (cells) of the planet?The Hadley Cell (around the equator)
The Polar cell (at the poles)
The Ferrel cell (between the Hadley and Polar cells)
27Describe winds at the Hadley Cell.Warm, moist air at the equator is lifted up into equatorial low pressure areas like the Inter-Tropical Convergence Zone (ITCZ) and carried poleward. At about 30°N/S latitude, it descends in a high-pressure area. Air from the North and South move in to replace air lost at the ITCZ, which is why it is called a convergence zone.
28Why is there nearly constant cloud formation over the Equatorial regions?Because of the rising warm, moist air at the ITCZ
29Describe winds at the polar cell.Air from the Hadley cell gets colder, and thus drier as it reaches the polar cell.
30Apart from the ITCZ, where and why is there cloud rich environments?At around 60°N/S latitude, because these are hot, moist air uplift zones.
31Diagram of Earth's atmospheric circulations.
32Where is the highest rainfall region of the planet?Around the equator, because this is where the hottest, warmest air is. This is where the tropical rain forests are found.
33What are the main ocean gyres (systems of circular ocean currents formed by global wind patterns and forces created by Earth's rotation)?1. Gulf stream
2. South equatorial current
3. Kuroshio current
4. California current
5. Antarctic Circumpolar Current
34Where do the major desserts form?The edges of the Hadley cell, because this is where the air has descended and is very cold and dry.
35Why is rainfall higher in areas that are higher up? So why does the UK have areas of different rainfall, despite having similar latitudes?Because air can store less water as it is pushed up, so the water condenses and falls as rain. The UK has areas of different heights.
36Oceanic circulation drives nutrients- "The Global Conveyor Belt". Explain 1, 2 and 3.1- Dense, cold, salty, nutrient depleted waters descending
2- Remineralisation of nutrients during transit (by taking dead, organic material). So deepest water tends to be the most nutrient rich.
3- Enhanced nutrients when surfacing
37What is upwelling?Delivery of deeper nutrient-rich waters to the surface, providing nutrients to areas across the ocean. This happens along coastal regions.
38What are teleconnections?Complications to circulations and distributions
39What is the El Nino Southern Oscillation (ENSO)?An irregularly occurring series of climatic changes affecting the equatorial Pacific region and beyond every few years, characterised by the appearance of unusually warm, nutrient-poor water. El Ninos affect the fishing ability in local areas badly.
40How does ENSO affect global circulations?The ENSO cycle, both El Niño (warm) and La Niña (cool), causes global changes of both temperatures and rainfall. The effects of El Niño include reversal of wind patterns across the Pacific, drought in Australasia, and unseasonal heavy rain in South America.
41What is the North Atlantic Oscillation?It is based on the surface sea-level pressure difference between the Subtropical High and the Subpolar Low. There are positive and negative modes, and they affect the weather globally.
42How does the North Atlantic Oscillation affect the UK?It affects the jet stream, so in the positive mode, we are warmer and wetter. In the negative mode, we are colder and drier.
43What things provide productivity in the ocean?1. Thermohaline conveyor belt (global conveyor belt)
2. Upwelling along coastal regions
3. Stream runoff (water from streams, rivers etc.) and dust (dust from storms etc. brings in nutrients to the ocean).
44What is the definition of soil?Unconsolidated mineral or organic material on the immediate surface of the earth that serves as a natural medium for the growth of land plants.
45What are the definitions of sediment?1. The matter that settles to the bottom of a liquid
2. Material deposited by water, wind or glaciers.
46What processes determine soil formation?Cl.O.R.P.T
Climate
Organisms
Relief
Parental material
Time
47How does climate affect soil formation?It determines microbial rate of decomposition.
48What is relief and how does it affect soil formation?It is sharp dips in the land, so soil will largely form in the dips.
49What is parent material and how does it affect soil formation?The soil forms from the bits of weathered ground material beneath it- the parent material.
Granite- more coarse
Olivine- less coarse
Shale, sandstone and granite- more acidic
Limestone- less acidic
50How does time affect soil formation?The younger the soils are, the less developed the horizons; the less thick they are.
51What can the amount of material broken down by microbes affect?Type of soil formation.
52How do herbivores affect soil formation?They only consume palatable plants, so other plants have a competitive advantage. This leads to 2 outcomes:
1: Unpalatable plants with poor litter quality dominate- diminished litter quality.
2:Unpalatable plants with high litter quality dominate- improved litter quality
53What happens if carbon is consumed from the top of the soil?There is less carbon available to go into the soil. This can have 2 outcomes.
1: Decreased root growth, so there will be decreased microbial activity and nutrient cycling.
2: There will be a higher ration of N in the roots, and a reduction in the number of secondary metabolites in the roots, so there will be improved litter quality and enhanced microbial activity and nutrient cycling.
54What 2 things determine litter quality?Herbivores and plant species present.
55In fertile regions, what is >50% of Net Primary Production (NPP) returned as?Herbivore fecal matter
56In infertile regions what is nearly all NPP returned as?recalcitrant plant litter
57What are the 6 soil horizons?
58How can organisms directly affect solid growth?Bioturbation (the disturbance of sedimentary deposits by living organisms)
Root growth and dieback
Fungal foraging
Most are climate sensitive to some degree.
59How do wetland soils like salt marshes and peetlands get their energy anaerobically?
60Does methanogenesis happen instantly after soil becomes waterlogged?The elements must be completely reduced before methanogenesis- can take a long time.
61Why does most methane never escape from the soil into the atmosphere?Because methylotrophs consume up to 90% of it first in the soil.
62What are some soil based feedback cycle examples?
63What does soil regulate for humans?Food, water, climate. Soil is non-renewable.
64Why are ocean sediments on a "conveyor belt"?Because of plate tectonics.
65Ocean sediments are determined by what?Biological and environmental drivers.
66What are abyssal sediments?Sediments formed by dust from the atmosphere.
67What is the biological pump between the surface and the deep ocean?The ocean’s biologically driven sequestration of carbon from the atmosphere to the deep sea. When diatoms and coccolithophores die they sink to the bottom and form sediment.
68How are oceans different at the surface and deeper down?Temperature- colder lower down.
CO2- more lower down- more is photosynthesised at the surface
O and nutrients- more at the bottom- respiration consumes O at the surface, dead matter sinks to the bottom producing more nutrients.
69What are diatoms?Plankton with hard parts made of silica- they tend to dominate in areas where nutrient availability is high.
70What are coccolithophores?Plankton with calcium carbonate hard parts- they tend to dominate in nutrient poor surface waters.
71Where is nutrient availability in oceans high (siliceous oozes)(and so where are diatoms found?)1) Thermohaline conveyor belt
2) Upwelling along coastal regions
3) Stream runoff and Dust
72What happens if CO2 is increased in low nutrient areas (calcareous oozes)?CO2 and calcium carbonate are in equilibrium. So if CO2 is increased, the calcium carbonate shells of the coccolithophores are dissolved more readily- the pH change means that the level at which calcium carbonate is dissolved is higher.
73Why are coccolithophore shells not found in deep water?The pressure is too high, so the shells dissolve
74What is the calcium carbonate compensation depth (CCD)?The particular depth level in the oceans where the rate of supply of calcium carbonate to the sea floor is balanced by the rate of dissolution.
75Where are calcareous oozes found?Higher up areas of the oceans.
76What are clathrates?These form within anoxic (oxygen depleted) sediments. Methanogenesis occurs in the sediments, and some of the methane crystallises into a snowball- clathrates.
77Why are clathrates worrying?there are lots in the world, and it's thought that if the oceans heat up too much, the methane will burst out of them, warming the planet catastrophically.
78What are aerosols?Any particles that exist in the atmosphere which incorporate dust (soil, volcanic eruptions, pollution) and bioaerosols (a suspension of airborne particles that contain living organisms or were released by living organisms).
79What things does a dust storm event affect?The radiative balance of the local region/planet
Distant ecosystems, both terrestrial and marine
80How can a dust storm affect the radiative balance of the local region/planet?The dust decreases amount of light coming in in that area. However because it is highly reflective, it increases the light in surrounding areas. So there is a change in temperature in the area where the dust is most concentrated and surrounding areas. This changes the way air circulates in these areas.
81How does a dust storm affect distant ecosystems, both terrestrial and marineIt carries nutrients to places that they would not normally go.
82How is abyssal clay formed?Dust lands at the bottom of oceans.
83How do abyssal clay regions affect the oceans?They will often be in areas that have low nutrients, so they provide nutrients in these areas.
84How would increasing nutrients in oceans that are normally low in nutrients by injecting them with nutrients be able to decrease CO2 in the atmosphere?The biological matter generated from these oceans will allow for phyloplankton to be able to store carbon which will sink to the bottom of the ocean.
85Why might this not work?Because the costs of driving a ship out into the ocean would be greater than the carbon stored from the process. Also, some of the carbon taken in by the plankton in the ocean would just be respired out again.
86What are phyloplankton?Photosynthesising microscopic organisms that inhabit the top layer of almost all oceans.
87What is the CLAW hypothesis?As the Earth gets warmer, phyloplankton become more active, so they produce more dimethyl sulfide. This is aqueous but some will dissolve into the atmosphere, where it will become sulphuric acid. Acids collect water and form small water rich aerosols (cloud condensation nuclei (CCN)). These back scatter incoming solar radiation, which cools the Earth's surface, reducing production of dimethyl sulfide- this is negative feedback.
88Why do the warming/cooling affects of CCN depend on their position in the atmosphere?If the CCN are low down in the atmosphere, like in the troposphere, the radiation can be reflected back on to the Earth's atmosphere, but if they are high up, like in the stratosphere, the radiation can be reflected back into space.
89What properties of clouds affect how they affect the radiative balance?Their size, shape, location and form.
90Why can't aerosols travel from the northern hemisphere to the southern hemisphere, but CO2, nitrous oxide, Sulfur dioxide can, and mix with the air all around the Earth?Because it takes about a year for air to travel from one to the other. This is because of the Inter- Tropical Convergence Zone. Aerosols only last for about 2 weeks. It only takes about a month to travel from East to west.
CO2, nitrous oxide, sulfur dioxide, have very long lifetimes, so they can mix throughout the planet.
91Why is warming global, but cooling hemisphere dependent?Because greenhouse gasses can mix in the air globally, whereas aerosols cannot.
92Why is the ITCZ shifting to the south?Because there is a build up of cold air in the northern hemisphere because of increased sulfur from human activity, which pressurises the air, shifting the ITCZ down. This makes the southern hemisphere drier and drier.
93What happens when there is a volcanic eruption in one of the hemispheres?The imbalance evens out for a while- the southern hemisphere gets wetter, the northern hemisphere gets drier.
94What 3 changes has the human takeover of the natural sulfur cycle led to?Changes in the Earth's radiative balance
Changes in the Earth's atmospheric circulations
Changes in local and global water cycling
95Why are rivers fuller due to increased aerosols?The planet has been cooled by increased sulfur, so less water evaporates from the surface. The increased CO2 means plants and other organisms transpire less, so less water is drawn from the soils, so there is more runoff into rivers.
96What is a hypothesis about biological aerosols?Biological aerosols seem to increase at the end of a rainfall event, so it is hypothesised that they can go into the atmosphere and form cloud condensation nuclei (CCN). This would produce more rainfall, producing more of the bioaerosol. This would be good for the organisms.
97What happens to the material in bioaerosols as it travels through the air?The viable biological material (material that grows when plated) is high relative to total material, but this drops as the time in the air increases. There is a question of whether the viable material can live and propagate in the atmosphere.
98What are the sizes of different aerosols?
99What are the three ecosystem services?Provisioning- goods produced or provided by ecosystems, e.g. grain, wood, water
Regulating- benefits obtained from regulation of ecosystem processes. e.g. regulation of malaria by mosquitos
Cultural- non-material benefits from ecosystems, e.g. art
100Define biodiversity'Biological diversity' means the variability among living organisms from all sources including, inter
alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are a part; this includes diversity within
species, between species and of ecosystems.
101What patterns of biodiversity does the Earth have?Vascular plants- more at equator, fewer at poles.
More vertebrates than plants at the poles.
102Is biodiversity always correlated to Net Primary Productivity (NPP)?No- it can be but some places have little biodiversity and a high NPP
103What determines biodiversity? (4 hypotheses)1) Age of ecosystem- time since last major disturbance
2) Climate range in tropical versus temperate environments
- Greater range of coverage possible for temperate species
3) Abundance and activity of insects in warmer climates. Insects can pass on disease more, so trees need to be further apart to avoid catching diseases from each other. This allows other species to move in (less competition).
4) Equatorial regions have more land mass, so there will be more biodiversity of land life.
104How does species number increase through competitive exclusion?More species occur when there are limited resources. Species differentiate resource requirements. This promotes speciation
105—When species compete with members of their own species, they broaden their niche because they all want the exact same resources.
But when different species compete, it is unlikely they will go for the exact same resources, so the niche narrows to avoid the niche of the other species.
106What determines whether a species settles in a habitat?
107What is the Grimes triangular ordination?
108What is the trade-off for plants?A long lifespan versus leaf mass per area (photosynthesis capability).
Seed mass versus seed number.
Height, stem density.
These things are determined by the environment the plant is in.
Plant functional types are not randomly distributed.
109What is an isotope?A form of the same element that contains equal number of protons but different numbers of neutrons in their nuclei, so differ in relative atomic mass but not in chemical properties (the number of protons determines behaviour of element). Some elements only have one stable isotope, other have radioactive forms.
110What are isotopes used for?Dating structures, looking at different metabolisms between C3 and C4 plants, Tracking butterfly populations, ocean circulations, organisms' trophic levels, determining the age of tree roots, budget balancing.
111What is the difference between radioisotopes and stable isotopes?The nuclei of radioisotopes will radioactively decay over time. there are 3 main types of radioactive decay; alpha, beta and gamma. The half-life is a very predictive tool.
Stable isotopes are stable and do not decay, even over very long time periods.
112What are the average terrestrial abundances of the stable isotopes H, C, O and N?
113Explain isotopic notation
114What is kinetic fractionation?A heavier isotope will have an increased bond strength, so all chemical and biological reactions will favour the lighter isotopes.
115What are diffusive, condensation/evaporation and equilibrium fractionations?The velocity of a molecule is inversely proportional to its mass. So the heavier isotope, diffusion is slower and equilibrium is reached after a longer period. Condensation is fast. Lighter isotopes evaporate faster and condense more slowly.
116Explain the effects of evaporation and condensation in the water cycle.The lighter isotopes in the ocean will evaporate to form clouds, and when the cloud water condenses, the heavier water will fall as rain, so then the water vapour will be very light.
117Explain the fractioning that occurs in a tree.The tree will preferentially take up carbon-12, so the atmosphere will be enriched with carbon-13. The tree will then produce root exudates, which will have undergone reactions, making the carbon isotope even lighter. So the exudates will be very light compared to the atmosphere.
118What proportions of the Earth's biomass are C3, C4 and CAM plants?C3- 95%
C4- 4%
CAM- 1%
119What can isotopes tell us about these plants?Their water use efficiency.
120How can isotopes tell us the trophic level of an organism?each time an organism eats something, it becomes more enriched.
121Why can this be difficult and not precise?Some organisms do not stay within their own trophic level- they may eat their own as well as the one beneath them.
122What can isotopes tell us about the oceans?Tracing tritium tells us about the ocean circulation.
123How can isotopes tell us about the age of tree roots?Bomb testing has elevated the level of carbon-14 over time by a discrete level, so we can look at the carbon-14 fixed by the roots of trees and match it to the year. They look at how quickly the plants transform the carbon they photosynthesis into tree roots, and how rapidly those tree roots decay. This tells us how ing the carbon resides in the terrestrial biosphere.
124Explain the monarch butterfly study.They wanted to find the origin of these butterflies. In butterflies, the wing tissue is representative of the time it was made- does not renew and repair. There is a relationship between isotopic ratio of wings and rainfall. From this they discovered that butterflies were travelling a long way in the US into Mexico.
125Peat biomes within the UK are different in terms of temperature, rainfall and topography. What is it that links the areas together?The saturation levels within the area.
126What drives peat production?An inability to decompose materia faster than it's produced.
127What historic events also drive peat formation?Ice ages. No peat could form when ice covered the land. So peat formation is maximum 50,000 years old.
128Why is there a question of how much peatland is formed from anthropogenic deforestation?Underneath the peatland there are often old tree trunks.
129What causes peat to grow?Low decomposition rates are caused by anaerobic conditions, in cold temperatures. Low nutrient availability locations- nutrients arrive in the form of rainfall, and are scavenged very quickly and retained, making them unavailable.
130What do these things lead to?A deep organic layer which is acidic (further halting decomposition). This limits the amount of phosphorus and nitrogen.
131Explain this peat cross section.Light only penetrates the top layer so only the top is growing. The acrotelm (the aerobic zone) is the growing, living portion of the peat in terms of plant biomass. The catotelm is saturated. Water and oxygen penetration here is very little.
132What does acrotelm build up do?Creates tussocks and hollows. This raises the water table- the level below which water doesn't drop.
133Water falls evenly across the peat, but as it dries out, water is patchy across it. What does this mean?This affects the nutrient and oxygen delivery across the site.
134What defines the community structure in peatlands?The water table.
135Which models best fit observations of communities in peat?Those that take into account water flow, nutrient uptake and availability, and peat growth.
136What types of plant are found in peatlands?Stress tolerators- not favourable environment, low disturbance.
137What are the characteristic traits of stress tolerators?Short, with thick tough leaves, inherently slow growing.
138What are the other 2 plant typesCompetitor (C) and Ruderal (R). They are faster growing.
139What do Rs and Cs invest in most?Rs invest most in reproduction.
Cs invest most in stem/leaf area/ roots
140Who's lifecycle is shorter, R or C?R
141Describe sphagnum moss that lives in peatland.Stores lots of water in their tissues. They keep their regions saturated, making an anaerobic environment around them, as a form of defence. They have a symbiotic relationship where nitrogen is fixed of them.
142Describe rushes/ juncos that lives in peatland.Spikey stems- they have oregima that deliver oxygen from the tips down to the roots.
143Describe heather that lives in peatland.Lives on the hummocks- parts of peat above water table. Has a fungal interaction, fungi access nutrients in the peat bog.
144Describe greater sundew that lives in peatland.They have sticky sap beads that trap bugs and obtain nutrients that they can't get from the peat.
145What are the nitrogen deposition effects (aerosol)?There is wet deposition of nitrogen and dry deposition- nitrogen lands on the ground from rain in the form of nitrate and ammonia (in aerosol form).
The increased N changes microbe behaviour and abundance- affecting peat.
146What kinds of forests do we find in the UK?Temperate seasonal forests, Boreal forests, temperate rainforests.
147What 2 things change the forestry in the UK?Temperature and Rainfall.
148Why are stress tolerant plants small?They need to be compact to retain their water.
149What do competitors look like?They are tall, like trees- large effort in building structural components- so much longer life.
150What are Boreal forests?Forests that developed from the last ice age- being squeezed out of the UK now. They are species poor relative to other boreal forests.
151Why is it beneficial for trees to block most sunlight beneath them (have a high canopy cover)?To keep competition down.
152What are the characteristics of trees found in boreal forests?S or C plants
Nutrients and water are available so height is required for maximum photosynthetic capacity.
Nutrients are available through ectomycorrhizal fungal symbiosis.
Evergreen trees have reduced sunlight interception and reduced leaf maintenance costs. Needleleaf morphology reduces water loss through transpiration.
The height of boreal trees is reduced compared to other forests. Evergreen shape aids in reducing snow-caused limb breakage. Dark pigmentation traps energy, warming needles.
Undercanopy is minimal due to greater canopy coverage
Litter fall causes acidic soil conditions
Pine trees generate terpenoids which act in defense
153What is woodland defined as?Vegetation dominated by trees over 5m high which form a canopy cover of more than 20%.
154What are the characteristics of trees found in temperate forests?All are C plants.
Beech, ash and oak are common, shading >40% of the available light before it reaches the under-canopy.
Deciduous trees maximize sunlight interception with high leaf maintenance costs.
Leaf litter produces rich, fertile soils with an active microbial cycling component (arbuscular/saprophytic)
The height of forest trees is in response to this competitive pressure. Cost of structural components is balanced against the benefits of maximum access to resources.
Shade tolerant species exist within the under-canopy, often separated in time to avoid direct competition. E.g.- bluebell and bracken carpets in early spring and late summer periods
155What are the characteristics of trees found in temperate rainforests?Similar selection of dominant tree species as temperate broadleaf forests but encompassing a diverse array of fungi, mosses and lichens.
156Describe rainforest lichen.Symbiosis - fungal partner and photobiont (photosynthetic organism) (green algae or cyanobacteria) Fungal partner protects photobiont from sunlight inundation.
NOT parasitic- obtains nutrients from air
Photobiont generates sugars from CO2 (and sometimes NH4+ from N2)
Up to 90% photosynthate donated
Fungal partner obtains mineral nutrients and protects photobiont from exposure
Indicator species for pollution- very affected by sulfur pollution.
157What can small changes in environment do to forests?They can have significant impacts on species biodiversity within the forest biome
Changes may not manifest in the dominant organisms
158What plant trade offs are made?of height, leaf longevity, leaf surface area/leaf mass, stem thickness and shape, and defense strategies.
159What are the types of deposition?Wet deposition (hail, rain, snow)
Occult deposition (fog, cloud)
Dry deposition (gases, particles)
160What are the different precipitation interactions?
161How do aerosols affect this?They will be in the deposition.
162Forests influence albedo.Different types change the amount of albedo.
163How do forests influence atmospheric chemistry by increased biogenic volatile compounds.
164What happens when these compounds interact with the atmosphere?They create ozone and smog, and increase the lifetime of methane in the atmosphere.
= increased global warming
165What do biomolecules from fungi do?Increase rainfall. But their emissions are themselves increased by rainfall. Positive feedback.
166Deposition increases nitrogen uptake in soil. What are the effects of this?This affects plant, microbial, and fungal species composition. Fun
167How do isotopes show us nutrient uptake of plants?Spray labelled isotopes of elements like N and see how much of that is in the plant a few days later.
168Evidence for communication across tree roots using isotopes?A carbon-13 labelled tree over 5 years. Evidence that other tree roots are somehow in contact, and are now taking up carbon 13.
169How much of the UK's land is pasture? (What is pasture)40%- grassland and other low lying areas suitable for cattle grazing.
170What are the carbon features of pastures?
171Why is carbon not retained too much by the soil?Organic fertilisers release C into soil, increasing decomposition of soil, so it retains less of the C.
172How much of the UK is peatland?15%
173Is peatland overall a carbon source or sink?Sink.
174How is C from peatland transported into atmosphere?Dissolved in streams, wind transport, gaseous C from water or directly.
175Summarise Peat Carbon
176What are salt marshes?Coastal regimes that are inundated with salt water twice a day- high levels of deposition, highly exposed.
177Why are salt marshes a net carbon sink?They have a high soil carbon accumulation rate. Anoxic conditions 9methanogens producing methane) mean decomposition rates are low.
178What fluctuations influence C in salt marshes?Temp- respiration/photosynthesis and decomposition changes
Tides and position of water table- high water table = anoxic soils= slow composition and methane production
Accretion/erosion- the build up of sediment or the release of salt marsh soil.
179How much of the UK is covered in forests?13%
180Salt marshes carbon cycle
181Forests carbon cycle
182What is arable land?Agricultural land
183What is sequestration?Th conversion of atmospheric CO2 into biomass via photosynthesis
184Nitrogen cycle in forests
185What happens to N levels when soil moisture increases?N increases
186Nitrogen cycle in pastures
187What is N fixation?When a symbiotic relationship forms between legumes and Rhizobium bacteria- reduces N2 to ammonia.
188What is N mineralisation?Decomposition results in ammonia formation
189What is denitrification?Under wet/ anaerobic conditions- bacteria transform nitrate into atmospheric N
190What is volatilisation?The transformation of ammonia into atmospheric N- occurs when temp high and ammonia exposed to air.