NPP from ec

Biodiversity and Change:

Biodiversity and Change

What is Biodiversity?:

What is Biodiversity? Try and find a good description of biodiversity It should have a general description and should refer to examples of ecosytems with different levels of biodiversity.

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Definitions….. Biodiversity is the variability among living organisms from all sources..... Terrestrial, marine and aquatic ecosystems and the ecological complexes of which they are a part: this includes diversity within species, between species and of ecosystems. Biodiversity is the totality of genes, species and ecosystems in a given area Biodiversity is the variation of life forms within a given ecosystem, biome, or for the entire Earth. A clear, concise definition …… p.38 IB Study Guide

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Species diversity- the number of species in a given area. Genetic diversity- The genetic variation within species. This can be in populations that have been separated geographically, but also amongst individuals within single populations. Ecosystem diversity- this looks at the variety of different ecosystems or habitats that occur within an area and takes into account the biotic and abiotic components.

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Biodiversity Range of species Total number of species Genetic diversity Ecosystem diversity Species diversity Endemics Species richness Abundance of species

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Can you explain why this happens

Why is there Greater Diversity in Equatorial Regions?:

Why is there Greater Diversity in Equatorial Regions? Simply – high rainfall, humidity and temperature all combine to make the area highly productive in producing plants – Explain this in terms of biodiversity.

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6H2O + 6CO2 ----------> C6H12O6+ 6O2

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Ecosystem Type Net Primary Productivity (kilocalories/meter 2 /year) Tropical Rain Forest 9000 Savanna 3000 Deciduous Temperate Forest 6000 Boreal Forest 3500 Temperate Grassland 2000 Polar Tundra 600 Desert 200 How can we Compare the Productivity of Different Ecosystems? The amount of energy that is photosynthesized and fixed is called the Gross Primary Productivity. However energy is lost in the process of respiration leading to the Net Primary Production.

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In addition to primary productivity being a major sink for atmospheric CO 2 , it is also the base of the food chain and allows humans and all Other creatures to live, and… It takes a lot of primary production to support higher trophic levels! The two important laws of thermodynamics. 1.Energy cannot be created or destroyed, only changed from one form to another. 2.All energy transformations involve conversion of energy to heat which is lost from the system .

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Questions to ponder upon. Between wolves and cows. Which is more likely to be a part of a food chain and the other part of a food web. Explain the difference. Why do vegetarians argue that their way of life is a far more efficient use of energy. Now have a go at question no 23 about trophic levels at back of your little booklet. (15 mins.)

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Controls on Net Primary Productivity Nutrients Question for thought: How could humans affect spatial and temporal variations in net primary productivity and biomass?

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Only about 44% of the total Electromagnetic energy reaching the earth is in the correct wavelengths for use by plants (called PAR) and only 0.5% – 3% of that is used!

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Temperature is a strong Limiting factor. Although plants in colder areas are optimized for Colder conditions

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Water also is a strong Limiting factor. Much steeper curve = A much stronger positive Reaction i.e. a little water goes a long way!

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If plants have enough water, enough sunlight, and are bathed in CO 2 , why don’t they “fix” more carbon, or grow more efficiently, faster, larger?

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Describe and Explain this table

Biomes of the World:

Biomes of the World

Tundra:

Tundra Located within 60 -90 0 N of the equator Temperatures are below freezing for most of the year Precipitation is in the form of snow and less than 120mm/year (it is technically a ‘cold desert’) Vegetation is low growing, wind and frost resistant lichens mosses and shrubs NPP : 140 gms/m 2 /year

Temperate Grasslands:

Temperate Grasslands Located mostly in the centre of continents within 40 -60 0 N & S of the equator Temperatures Winters are cold (-20 0 C) summers are hot (+20 0 C) Precipitation is in the form of snow in winter and heavy showers in summer. Annual totals in the order of 400mm/year Vegetation is almost entirely grassland. The wetter the area the taller the prairie grasses. Human use of these areas is dominated by wheat and cattle farming. NPP : 600 gms/m 2 /year

Temperate Deciduous Forest:

Temperate Deciduous Forest Located 40 -60 0 N & S of the equator, nearer the coasts Temperatures Summers are relatively cool, winters are mild Precipitation is mostly rain which falls in the winter months. It totals around 1000mm/year Vegetation is deciduous woodland (oak, ash, elm and beech) which lies dormant in the winter when light levels are low NPP : 1200 gms/m 2 /year

Rainforest:

Rainforest Located within 10 0 N or S of the equator Temperatures are high all year Rainfall is over 2000mm and falls throughout the year Vegetation is dense and mostly trees often found in 3 layers – shrub layer, canopy and ‘emergents’ (forest giants) NPP : 2200 gms/m 2 /year

Tasks:

Tasks Describe and explain the location of Tropical Rainforests in the world. 2. Find some facts and figures about biodiversity in Rainforests that I can use to fill in the next two slides. Why is the rainforest so biodiverse What amazing facts about its biodiversity can you find – with examples. 3. How might the existence of different layers in the forest account for higher biodiversity

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As you can see certain physical and human factors will account for the level of biodiversity in an area. One physical factor yet to cover is

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Task: Redraw this to show what would happen after large scale deforestation.

Next:

Next Causes and consequences of reduced biodiversity.