Energy And Ecosystems, Nutrient Cycles, And Succession Booklet

Front 1

Producers

Back 1

Plant and algae photosynthesise

Glucose synthesised have bonds which contain light energy and chemical potential energy

Glucose formed can be used in respiration to produce water and carbon dioxide and water heat energy OR glucoses can be used to make other molecules eg starch, cellulose, amino acids which are the plants BIOMASS.

Front 2

Biomass definition

Back 2

Biomass is all the biological molecules made by the plant and are not immediately used for respiration. It represents the growth of the plant.

Front 3

How is biomass measured?

Back 3

It's a measure of the mass of carbon in the biological molecules

Measured as dry mass

Can be used to measure the energy value as each molecule making up the biomass strores energy in their bonds.

Front 4

Practical estimation of dry mass

Back 4

1. Heat in a low temp oven to evaporate water in the tissues. (No higher than 100°c or else dry mass will burn and energy cannot be calculated)

2. Continue measuring biomass until there is no further change.

3. Calculate biomass in Kgm-2y-1

4. Carbon content estimated as 50% of dry mass.

Front 5

Why do we use dry biomass rather than wet biomass?

Back 5

Water content of different organisms will vary. Water is not made by the plant In photosynthesis so therefore water is not biomass.

Front 6

What are the units for dry mass and the energy value?

Back 6

Front 7

What is the explanation of the units for dry mass and energy value?

Back 7

So that we can FAIRLY COMPARE biomass produced in different plants in different habitats. Taking in to account:

- The size of the area it has come from (m-2/ metre)

- the time period (yr-1) growth rates vary with the time of year so take into account the whole year.

Front 8

Practical technique for obtaining energy value in dry biomass

Back 8

Biological molecules store chemical potential energy.

Dried biomass is put in a calorimeter

Dry biomass is then combusted

Energy released is used to heat water.

The change in water temp is used to calculate the energy released.

Front 9

Gross primary production : GPP

Back 9

The total amount of light energy captured in photosynthesis and stored in molecules as chemical potential energy.

Front 10

Respiration (R) definition

Back 10

The amount of energy lost from the plant in respiration. This returns to the environment as waste heat.

Front 11

Net primary production (NPP)

Back 11

This is the remaining amount of chemical potential energy stored in the biomass of the plant. This can be used for growth and reproduction.

Front 12

Equation linking GPP, R, NPP

Back 12

NPP = GPP - R

Front 13

Why is NPP important?

Back 13

This is the energy in the new biomass of the plant. Used to make cells, tissues for growth, reproduction. What can energy can be transferred to consumers.

Front 14

What happens the the NPP in producers that are consumed by animals?

Back 14

Gotten from Ingesting (I)

Used in Respiration (R)

Lost by Faeces and urine (F)

Used in Growth (N)

Front 15

Net production equation

Back 15

N = I - (F +R)

Front 16

Using Sankey diagrams

Back 16

Front 17

Trophic levels

Back 17

Front 18

Why do trophic levels get narrower as you move up them?

Back 18

Energy is lost to decomposers as faeces, urine and uneaten material + energy is lost through respiration by the consumer.

Front 19

Efficiency of energy transfer equation

Back 19

Front 20

Why are food chains only usually 4 organisms long?

Back 20

Energy transfer is decreased between each trophic level and used into making flesh.

Front 21

Maximising efficiency in food production

Back 21

Front 22

3 key processes of nutrient recycling

Back 22

Uptake

Feeding

Decomposition

Hint 22

Front 23

Mycorrhizae

Back 23

Fungi that live in close association with plant roots. Final hyphae provide a large surface area for uptake of minerals from soil. In return plants provide carbohydrates. Example of mutualism

Front 24

The nitrogen cycle

Back 24

Front 25

Nitrogen fixation in the nitrogen cycle

Back 25

Plants cannot use N2 because the triple bond is too strong.they rely on nitrogen fixing bacteria to convert N2 to ammonia NH3 which can then be used in making amino acids.

Front 26

Where do nitrogen fixing bacteria live?

Back 26

Some love in the soil but most live in roots of the plant in root nodules (swelling of the roots)

Mutalistic relationship where the bacteria gain carbohydrates

They live in communities - most are in the family Fabiaceae most commonly called legumes.

They are usually grown to improve soils. So these plants are ploughed into the soil and decomposes and the fixed nitrogen can be used in the next crop

Front 27

Ammonification - nitrogen cycle

Back 27

Nitrogen containing compounds in dead plants, animals and in faeces are used by saprobiont bacteria in the soil. They digest proteins by secreting enzymes and absorb amino acids. They excrete ammonia and ammonium ions as waste products.

Front 28

Denitrification - nitrogen cycle

Back 28

Waterlogged soils contain bacteria which use absorb nitrates and convert it in to nitrogen gas which is released back into the atmosphere. This can only happen in conditions without oxygen.

Front 29

Soil nitrate concentration

Back 29

Hint 29

BLAPD WHO?

Front 30

Phosphate cycle

Back 30

Front 31

Natural Vs agricultural cycles

Back 31

In both minerals are taken up from soil by plants ms used to make biological molecules such as proteins and DNA.

However in in natural cycles bacteria and fungi decompose the plants and bio molecules and the cycle starts again. Where as in artificial cycles the plants are harvested meaning no decomposition so a fertiliser is added instead.

Front 32

2 types of fertilisers

Back 32

Artificial : inorganic chemicals such as ammonium nitrate and these come in powders or pellets . They are water soluble

Natural: manure or compost they slowly decompose to release minerals.

Front 33

Leaching

Back 33

When artificial fertilisers are easily washed off due to their solubility. Eventually these end up in water ways causing eutrophication

Front 34

Eutrophication

Back 34

Front 35

Succession

Back 35

The way an ecosystem changes over time. Different communities of plants will replace each other in a predictable way making changes to the habitiat,along it less hostile for the next community of plants.

Front 36

Sere

Back 36

A plant community

Front 37

Climax community

Back 37

The final community . Usually a forest. The climax community is usually stable, resilient to change, and long lasting.

Front 38

Stages in succession

Back 38

Pioneer community

Moss sere

Herbaceous sere

Shrub sere

Tree sere

Climax community

Hint 38

6

Front 39

Initial conditions before the pioneer community

Back 39

No soil, few available minerals, high light intensity, extremes of temperature, windy

Hint 39

5

Front 40

Pioneer community

Back 40

On bare rock lichens are the pioneers. - when they die they decompose into organic matter called humus. Creating thin soil being able to retain moisture and slowly release nutrients through decomposition.

On sand dunes marram grass is the pioneer species.

Front 41

Moss sere

Back 41

Misses and grass germinate and grow using moisture held by the thin soil. The decompose adding to soil layer.

Front 42

Herbaceous sere

Back 42

In the less hostile conditions, plants requiring more water can now germinate and grow. These include herbaceous plants such as ferns and grasses. They germinate rapidly due to wind dispersed seeds. They will out compete mosses for light and space.

The plants grow taller and they will reduce wind speed and light intensity at soil level helping retain soil moisture and seeds to germinate

Front 43

Shrub sere

Back 43

Sub-climax community

Soil is deeper, More humus, and pH is closer to neutral. Water availability, light intensity, and wind speed improved. Larger shrubs can grow eg bramble and hawthorn.they grow fast and outcompete the lower level herbaceous species for light and space.

Front 44

Tree sere

Back 44

Woody trees.

Climax community

Final community provides a diverse set of niches to support complex food webs and trophic level interactions.

Front 45

Moving from one sere to another

Back 45

Each sere makes the environment less hostile

Each community out competes the one before

Each sere becomes more diverse

More niches

Front 46

Secondary succession

Back 46

When a climax community is removed by humans or destroyed the pioneers will re-establish and succession starts again. Secondary succession is usually much quicker as there is already well developed soil.

Front 47

Plagioclimax

Back 47

Humans stopping natural succession is called plagioclimax. Usually humans use animals to stop succession. The animals will graze of plants preventing succession

Front 48

Conservation methods

Back 48

Managing succession - mass farming and grazing livestock presents succession. Limits on the number of animals and farmers is managed.

Seed banks - endangered species seeds are kept.

Captive breeding - breeding of endangered species

Protected areas - national parks and conservation's areas

Fishing quotas - limits are placed on sizes and number of fish caught