l1 ap 2014 defining bio
TRANSCRIPT
The 6 topics of Contested Planet
• The 6 topics in Contested Planet combine into a linked sequence.• This firstly explores resources, then the differences between rich
and poor. • Finally a range of solutions to global problems and inequalities are
examined in ‘Technological Fix’. This last topic is summative and would benefit from being taught last.
Exam Unit 3
• Summer 2015
• Two and a half hours.
• Section A: – Five topics from the six studied. Answer two
questions, each has a section a and b.
• Section B: – Pre release booklet, 1 question, with three
parts, based on one of the six topics. Answer all three parts
Anagrams
• revitoydiibs• Biodiversity• mesiob• Biomes • roftanires• Rainforest • ticrac• Arctic • emtsysoce• Ecosystems
What is an ecosystem?
What is a biome?
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving, physical components of the environment with which the organisms interact, such as air, soil, water, and sunlight. It can be as small as a hedge or as large as a rainforest.
Biomes are climatically and geographically defined similar climatic conditions communities of plants, animals, and soil organisms over normally a large area. E.g. Desert.
Defining biodiversity • Biodiversity can be defined in a number
of ways. One of the most common ideas is that it has three dimensions
• Species diversity is the most commonly used definition.
Bio…?
•Biodiversity – the variety of genes, species and ecosystems in an area. •Biosphere – the thin veneer of living material on the planet’s surface•Biome – a global scale ecosystem e.g. tropical forest •Biomass - the total weight of living matter per unit area (dry)
What is Biodiversity?
“The variety among living organisms from all sources including, amongst other, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems.”The Convention on Biological Diversity
Biodiversity Key Facts• Since the beginning of the century about three-quarters of the world's crop plant varieties
have been lost, and around 50,000 varieties disappear every year.• The world's population obtains about 90% of its calories from 20 crop species.• Tropical forests and woodlands contain at least 50% of all known plant and animal
species.• Some 40% of the world's market economy is based on biological products and processes.• At least 7,000 medical compounds in Western pharmacies from aspirin to birth control pills
are drawn from plants, mostly from less economically developed countries.
Why is Biodiversity Important?
Why biodiversity is
important?
Biodiversity supports complex interactions between plants, animals and people
Biodiversity provides essential goods and services, e.g. food, medicines, raw materials
Biodiversity and natural processes are environmental regulators, e.g. flood control, soil erosion, clean air etc.
Biodiversity has aesthetic and spiritual value – quality of live / health is closely linked to the environment
Biodiversity is valuable for recreation, e.g. in the countryside and urban natures areas
Genetic biodiversity can control a agro-ecosystem resistance to pests / diseases
What is biodiversity? (p66 in text book)
Biodiversity
Species diversity
Ecosystem diversity
Genetic diversity
Endemism(Uniqueness)
Disparity
(Different species)
Species Richness (how many species)
Abundance of species
Total no. of species
A. What is genetic diversity?
Range of genes found within a species. The diversity will often determine the degree of resistance to pests and diseases.
In Agribusiness, breeding new varieties of cereals has led to genetic erosion and genetic pollution. This can weaken the plant’s resistance.
What impact could this have in the future on food
security?
B. What is species diversity?
This is the number of different species in a given area. The ideas of ‘species richness’ and resilience to change. Most common ‘definition’ of biodiversity.
Diversity is needed to enable the ecosystem to carry out its functions such as carbon cycling.
What will removal of species from trophic levels have on energy
flows and nutrient cycles?
C. What is ecosystem diversity?
Range of ecosystem found within an area. The diversity will often determine the degree of resistance to pests and diseases. It is partly controlled by physical conditions, e.g. climate. This includes both biotic (plants and animals) and abiotic parts (soils, geology and climate).
Parakets Humans can alter and eliminate ecosystems (e.g. …………….) and this is an obvious threat to ecosystem diversity.
What local ecosystems are under threat here from
humans?
Advantages Disadvantages
Genetic Diversity Genetic variation within species
Helps explain how isolated groups (e.g. Birds) have adapted to new environments.
DNA has to be analysed so needs high level biological skills.
Species Diversity Number of species in given area
Good basic definition.
Size of area can create problems, larger area means more species. Need to compare like for like.
Ecosystems diversityVarity of ecosystems within an area
A more complex measure of interaction of species with environment. Has a wider focus
Where do you place the boundaries? Needs a constant set of criteria to demarcate the area.
What are the different advantages and disadvantages of using these three different categories to help define Biodiversity?
Biodiversity is the sum of all three definitions. Whilst species richness is easy to measure, biodiversity also clearly includes reactions between species and their environments.
Biodiversity hotspots – areas of very high biodiversity values.
Combined area covers only 2.3% of the Earth's land surface. Each hotspot has already lost at least 70% of its natural vegetation. Over 50% of the world’s plant
species and 42% of all terrestrial vertebrate species are endemic to the 34 biodiversity hotspots.