Lecture 6 Flashcards
What is an ecological scale? Explain
Is about the level in which we look at something in ecology e.g. do we watch an individual or a group, a group plus their prey. A group plus their prey plus what the prey feed on etc.
So can look at one trophic level of all of the trophic levels
What does the ecological scale depend on?
Depends on the question you are trying to answer
If you look at a very large spatial scale the distribution of biomes is mostly determined by what?
Temperature and precipitation, is a combination of the two e.g. different temps and precipitation would influence what species of tree grow somewhere
The properties of an ecosystem aren’t just defined by the ecosystem itself. What else can they be defined by?
What’s next to the ecosystem. Ecosystem boundaries can be ecosystems of their own right (could be a gradual change or could be a sharp change)
What is the extent of spatial scale and ecological processes?
Overall area encompassed by a study (e.g. the total size of a protected area you are studying)
What is the grain of spatial scale and ecological processes?
Size of the individual units of observation (e.g. the grid cell size)
Why can’t we detect patterns below the grain?
Research gained at small spatial scales are often not representative of larger areas, the large-area averages may be meaningless at smaller scales
What do general circulation models stimulate? How do they do this?
The response of the global climate system to rising greenhouse gas concentrations.
Done by:
. Depict climate using a 3D grid over the globe, typically with a horizontal resolution of 250-600km
. Represent physical processes in the atmosphere, ocean, cryosphere and land surface
What are the issues with general circulation models?
Because of their resolution:
. Miss fine details on vegetation and feedbacks with climate
. Many physical processes, such as those related to clouds, also occur at smaller scales and cannot be properly modelled (averaged over larger scales
These finer details are important for predicting local climate change and its impacts on ecological processes
What are general circulation models used to predict?
Species distributional responses to climate change and this is a challenge because ecological studies are usually carried out at magnitudes several times small than these GCM’s
What is vegetation climate feedback?
When the climate affects the vegetation which in turn affects the climate and the effects of these feedbacks can be extremely difficult to model and this can lead to large uncertainties in our predications of future climate change impacts
What causes uncertainties when making climate change models?
. Uncertainties are introduced if he spatial resolution of the data/ model is coarse relative to the scale of ecological impact assessments
. Measurements made at different spatial scales are not necessarily directly comparable
How is climate change predicted to influence crop productivity?
Is predicted to change it, especially in vulnerable regions which will lead to food insecurities in the future
What are the implications of scale?
Has strong implications for the sampling design of our ecological studies: it impacts in interpretation of results and on understanding the links between patterns and processes operating at different rates/ scales
What do scales profoundly influence?
Our ability to predict responses of biodiversity to change
What is scale?
Space, time and ecological understanding
What do ecological processes often operate within? Use an example to explain
Nested spacial and temporal scales e.g. if we are going to analyse carbon biomass dynamics in a forest ecosystem at the very smallest spacial and temporal scale you have leaf physiology, if you move it both spacial and temporal then you’ve got whole tree physiology and if you keep moving up these scales until you are looking at the entire forest