Ecosystem Responses To Climate Change Flashcards
What are consumers
Organisms that feed on plants or on other organisms (microbes, animals)
What is phenology
Study of timing of development in plants and animals
What are the direct effects of climate change on consumers
Phenology and growth
Phenology of plants
Budburst
Flowering
Leaf fall
Phenology of animals
Emergency from hibernation
Reproduction
Migrairon
How does climate change effect warm blooded animals
They are buffered from direct temperate effects so metabolism isn’t directly effected.
Responses to climate change more likely to be indirect via food or wider ecosystem.
How does climate change effect cold blooded animals
Physiology, growth and development often tightly coupled to temperature
What is the relationships between temperature and growth in cold blooded animals
Linear.
No development below 10C.
Above 10C each 5*C increase in temperature produces a constant increase in development
What happens when the relationship between development and temperature is linear
It is often possible to summarise temperature effects in terms of accumulated temperature above the threshhold
What is a degree day
How many degrees is above the threshhold temperature for how many days. Times together e.g 2d @5*C is 10 degree days.
When does a given developmental stage occur
At a set number of degree data
Example of animal with a linear relationship between temperature and development
White cabbage butterfly
Facts about the white cabbage bitterly
Development from egg hatching to pupation is 174 degree days above a threshhold of 10.5*C
What is the predicted effect of animal development in higher temperatures
Development starts earlier in spring and doesn’t stop over winter.
More generations per year so greater population build up.
Species currently constrained by threshold temperatures may move north or beyond favoured habitats.
What is happening to amphibians in the uk
They are spawning earlier. Around 10 days over the last 20 years.
What has happened to insects in the northern hemisphere
They are extended their range northwards including some plant pests and vectors of human disease
What are happening to insects
Extending their range to higher altitudes and disappearing at lower elevations in some cases
What is happening to Uk birds
Extending their range northwards at 6miles a decade and breeding earlier at 1 week in 20 years
What are three diseases that are likely to move due to climate change
Malaria (mosquito)
Dengue fever (mosquito)
Schistosomiasis (water snail)
What is 1*C temperature rise in Rwanda associated with
A 337% increase in malaria
What do models predict that a 3*C warming would lead to
50-80 million additional cases of malaria per year worldwide
Why may changes in herbivorous insects be secondary
Changing in response to the effects of warming on plant development
What do all plants have
Characteristic temperature responses - different optimum temperatures
What are differences in optimum temperature due to
Differences in metabolism of species
What is the optimum temperature of C3 plant oil seed rape
24
What is the optimum temperature of C4 plant Maize
33
What is the effect on crop plants or temperature increases
Unlikely that increasing temperature will limit agricultural pridcution.
Secondary wffects limiting.
Some crops will be able to be grown north.
What is the effect on UK native species in temperature increases
We will lose plant species, locally and nationally.
We may see some new species as well.
What was the change in geographical range of stemless thistle
Southern distribution and likely to expand and invade north
What was the change in geographical range of wood cranesbill
Widespread, typically northern distribution. Likely to retreat north as it needs cooler temperature.
What was the change in geographical range of yellow mountain saxifrage
Arctic alpine species in the UK at the southern limit of their range in the highlands, snowdonia and Lake District. Retreat north.
What was the change in geographical range of alpine meadow rue
Arctic alpine species in southern limit in highlands. Snowdonia and Lake District. Retreat north.
What was the change in geographical range of twinflower
Arctic alpine species in southern limit in highlands. Snowdonia and Lake District. Very little left will significantly retract
What was the change in geographical range of drooping saxifrage
Arctic alpine species in southern limit in highlands. Snowdonia and Lake District.
Most extreme part of range. Will disappear
What is specious development well correlated with
Accumulated temperature above a threshhold minimum
What can degree day models predict
Many developmental responses
What is the minimum temperature for oilseed rape
7
What is the minimum temperature for maize
12
What happens between minimum and optimum temperatures
There’s a relatively linear relationship so can predict growth rates
What are the recent trends in the Uk
Growth parameters are changing and spring is getting earlier, autumn is getting later. Encroaching the threshhold required for flowering earlier, later developmental processes occur it later. Stretching the growth season/phase
Why is low temperature essential for development in plants
Many developmental events have a requirement for periods of low temperature which will be lost if temperatures keep going up
What is the recent trend in the Uk for hazel flowering
23 days earlier
What is the recent trend in the Uk for emergence of snowdrops
7days earlier
What is the recent trend in the Uk for bluebell flowering
16 days earlier
What is the recent trend in the Uk for alder leafing
13 days earlier
What is the recent trend in the Uk for hawthorn leafing
17 days earlier
What is the recent trend in the Uk for beech leaf colouring
12 days later
What is the recent trend in the Uk for oak leaf colouring
9 days later
What is the recent trend in the Uk for beech leaf fall
12 days later
What is the recent trend in the Uk for oak leaf fall
5 days later
What are the 3 developmental stages low temperatures are essential for
Seed dormancy
Flowering in trees
Flowering in winter cereals
What is seed dormancy broken by
Periods (weeks-months) of low temperature (stratification)
When can flowering in many trees occur
Only after exposure to periods below a certain temperature
When does flowering in winter cereals depend on
A period of Low temperature (vernalisation)
What happens without exposure to low temperature in some crop cultivars and native species
They will not germinate or flower normally
What would be the solution to not having periods of low temperature for crops
Change to different cultivars like s.europeqn
What happens due to native plants not getting low temperature periods
Different species respond differently leading to altered competition and other interactions.
Some species gqin and other lose impacting biodiversity.
Plants and animals may respond differently causing loss of synchrony between plants and the animals feeding on them.
What are the consumer response to plants changing
Altered decomposition of plant litter
Altered herbivory and disease
Loss of fitness due to herbivory and disease altered
What 4 things does elevated co2 effect in plants
Storage
Defence
Growth
Reproduction
How do plants use elevated co2 to store
Plants use fixed carbon and store it due to damage to photosynthetic tissue. Use this to replace damaged organs.
How do plants use elevated co2 to reproduce
Transfer their genetic material into the next generation
What is defence
Plant characteristics that reduce/ prevent attack by primary consumers
What are the plant properties affecting herbivory
Tannin concentration Fibre content Cellulose content Toughness Water content Nitrogen concentration
What is the gradient between increased foliage herbivory and tannin concentration
Negative
What is the gradient between increased foliage herbivory and fibre content
Negative
What is the gradient between increased foliage herbivory and cellulose content
Negative
What is the gradient between increased foliage herbivory and toughness
Negative
What is fibre closely linked to
Lignin content
What is the gradient between increased foliage herbivory and water content
Positive
What is the gradient between increased foliage herbivory and nitrogen concentration
Positive
What is nitrogen concentration often expressed as
C:N ratio. More carbon relative to nitrogen increases ratio
What is the gradient between increased foliage herbivory and the C:N ratio
Negative
What are the correlation between rate of mass loss and leaf litter characteristics in decomposing birch leaves for tannin concentration
Negative
What are the correlation between rate of mass loss and leaf litter characteristics in decomposing birch leaves for lignin content
Negative
What are the correlation between rate of mass loss and leaf litter characteristics in decomposing birch leaves for nitrogen concentration
Positive as more nitrogen more decomposition
What are the correlation between rate of mass loss and leaf litter characteristics in decomposing birch leaves for C:N ratio
Negative
What are the correlation between rate of mass loss and leaf litter characteristics in decomposing birch leaves for lignin:N
Negative
What do higher concentrations of tannins and lignin do
Inhibit consumers (induction of the phenylpropanoid pathway). Make tissues tougher, harder to digest
What does lower concentrations of nitrogen do
Inhibit consumers and makes tissues less nutrious
What influences the balance between the four end points of elevated carbon
Photosynthate (C)
Nutrients
Water
But different end points may need different relative amounts of different resources
What do growth and reproduction have
Relatively high requirements for non photosynthate resources (nutrients and water)
What are the 2 environments that influence the balance between end points
Non-photosynthate resources are freely available (non limiting to growth)
They are not freely available and so limiting to growth
What happens in the not limiting environment.
Extra photosynthate can support increase in all four end points so everything increases
What happens in the limiting environment
Extra photosynthate can not support increases in growth or reproduction bc mineral and water resources they are dependent on is limited.
Do not grow more, but store more and increase defence. Decrease herbivory, disease and decomposition
How many storage also influence defence
Storage may be in specific tissues or organs like a build up of starch.
More stars is more fixed carbon.
If nitrogen is limitint then increases in C will result in increases in the C:N ratio.
Negative correlation between ratio and herbivory.
Increased storage under elevated co2 may contribute to defence by increased ratio.
How may storage influence photosynthesis
the starch build up in leaves inhibits photosynthesis.
The effect of elevated co2 on photosynthesis may be self limiting.
What is the experimental data on elevated co2 and herbivory
Aspen oak and maple. 2 columns one is ambient co2 other is elevated.
What does the experimental data show happens for plant growth
Goes up. 2/3 significantly.
What does the experimental data show happens for nitrogen
Goes down (C:N ratio goes up). 2/3 significantly
What does the experimental data show happens for toughness
Goes up (2/3 significantly
What does the experimental data show happens for starch
Goes up. 2/3 significantly
What does the experimental data show happens for water content
It goes down. 2/3 significant
What does the experimental data show happens for tannin concentration
Goes up 1/3 significantly. Suppresses interactions with consumers
What happens to larvae in aspen in the experimental data
Development was slowed down.
Growth rate reduced.
Weight was reduced.
What animal did the experimental data use to figure out larval situairosn
Gypsy moth and species that can cause major forest damage during population explosions
What does all the experimental data point to
Elevated co2 inhibits growth and development of the herbivore as predicted especially on aspen. However moth tries to adjust for its food quality by eating more. Primary effect on insect is predictable but behavioural responses are not.
What does the experimental data for elevated co2 and decomposition state
Under elevated you get increased carbon, decreases nitrogen, increased ratio, increased tannins and increase in toughness which all negatively correlate with decomposition.
Decomposition reducesd in 3/4 species (ash, birch, sycamore) not spruce.
Less loss of carbon from litter so negative impact on decomposition.
What is the conclusions of the experimental data on decomposition
Co2 does reduce decomposition.
Co2 reduces recycling of both nutrients and carbon.
Increased ‘sequestration’ of C in litter could help restore the overall global C budget.
The effect of warming has the opposite effect in the short term releasing carbon.
