ecosystems

Energy in ecosystems

Sun is a source of energy for ecosystems

Energy is trapped + fixed in the ecosystems by green plants in the process of photosynthesis

Energy is trapped by chlorophyll + used to chemically combine water (soil) and CO2 (air) to form carbohydrate + O2 (released to air)

Green plants occupy trophic level → AUTOTROPHS/ PRODUCERS

All subsequent/ later trophic levels get their energy directly/ indirectly from green plants

They can’t photosynthesise - Heterotrophs

TL2 herbivores TL3 carnivores TL4 omnivores

What are decomposes

Decomposers e.g bacteria/ fungi operate at each trophic level by breaking down dead organic matter + releasing nutrients to soil,

What is biomass

Dry weight of living matter usually expressed as Kg/ m2

Why does energy decrease with each trophic level

• used by organism for movement respiration, digestion etc

• Bones, teeth, fur, nut shells are not eaten

• Biomass that can be supported decreases and number of organisms decreases.

The nutrient cycle

One small scale case study of how an Ecosystem Functions

Breenwood Co. Antrim

What is the type of ecosystem at breenwood Co Antrim

Deciduous woodland- mainly oak trees

Where is Breenwood located

6 miles from ballycastle, in County Antrim

Abiotic relief aspect of Breenwood

North facing slope of a valley 130-190m above sea level

Abiotic climate of Breenwood

High annual rainfall around 1600mm (high)

January - 4oC , July - 15oC

Very cloudy most days, winter frost common

Short growing season of 7 months

Abiotic soil in Greenland

Formed from basalt a podzol

Low in nutrient soil, thing rocky, acidic pH 4.5

Thin humus layer bleached

What is the autotrophs/ producers

Trophies level 1

Dominant species is oak but they are stunted. Also downy birch in Canopy

Shrub layer - rowan hazel Holly

Field layer - bilberry bramble fern

Soil surface mosses ferns

On branches and trunks of living n dead trees - mosses, lichen, ferns

Early spring - before tree gets leaves there are bluebells and anemones.

Primary consumers herbivores TL2

Insects, butterflies (orange tip) red squirrels

Secondary consumers TL3 carnivores

Blue tits + gold crest are birds that eat seeds + insects

Tertiary consumers TL4 herbivore

sparrow hawks + buzzards feed on smaller birds

Badger feeds on small birds + fruits + nuts

Stoat - squirrels + birds

All TL decomposers

Earthworms fungi insects

Why is the biomass large

Biomass is the largest store because it’s a mature deciduous woodland that’s an ASSI, so it’s protected

reasons for small litter

The trees lose their leaves in the autumn and it can take take years for them to break down in this hostile (cold and acidic) environment

Why soil stores are low

Because the parent material is basalt which is very low in nutrients . Pod soil is also heavily leached because precipitation is high at 1600mm and rates of evapotranspiration are low as temperatures are 4oC to 15oC, so the overall movement of soil water is downwards .

Why is the uptake pathway low

Because there is a 7 month growing season which is very short and this is not a dense forest due to the harsh climate conditions.

Why is the fallout pathway high

Every autumn deciduous trees lose their leaves, so there is an annual contribution of dead organic matter to little

Why is the decay pathway

The dead organic matter breaks down slow because of the low temperatures (4-15oC) and acidic environment - which renders decomposers less effective.

the inputs of breenwood

Input if nutrients from precipitation (1600mm/yr) is higher that that from weathering of basalt. Precipitation is high in this upland areas, whereas the basalt is low in nutrients

Output of nutrients

From runoff and leaching is high as there are high rainfall totals (1600mm) and low temperatures.

The ecosystem is on a slope which is also contributes to the high loss of nutrients