Flashcards in Observing And Mapping Biodiversity Deck (15)
What are the two methods for linking past climates to biodiversity?
1. Geology: look at the conditions of rocks
2. Biological materials: look at fossils e.g crocodiles can be found in the Arctic
What is a good preservative of biological materials?
Peat e.g Tollund man
What is palynology?
Pollen grains are resistant to corrosion and are species specific
Pollen grains can indicate plant species present at that time
Give an example of a fossil that can estimate past temperatures, and describe how it does this:
Deep sea Foraminifera
Warm temp (more than 8-10 degrees) = right hand coiling
Cold temp (less than 7 degrees) = left hand coiling
How do stable isotopes show past temperatures?
Samples depleted in the lighter isotope indicate a warmer climate because they evaporate quickest
What are the 3 causes of glaciations?
1. Eccentricity: earths orbit around sun isn’t circular
2. Obliquity: angle of the earth tilts 2.4 degrees every 41,000 years
3. Precession: direction of earths axis relative to the stars
What was found to be the most abundant plant species in London clay 65 million years ago?
Palm: indicates a much warmer climate
What is amelioration?
Melting of ice and re-invasion
In the last full glaciation where in Britain was left exposed?
South east England
How is the iris plant an example of speciation due to glaciation?
In America iris setosa pushed south and crossed with iris Virginica to produce iris versicolor
When glaciers retreated so did iris setosa
What are eco regions and how many are there?
Defined as areas that have distinct biotas that can’t be found anywhere else on earth
What are biodiversity hotspots and how many are there?
Where there are unique species and biodiversity is decreasing at an exceptional rate
Where is the maximum number of species of various organisms found?
Slightly north of the equator
How does the physical structure of vegetation influence biodiversity?
The more canopies/layers the more microclimates, which means more niches for species= higher biodiversity