1. Limiting Factors Which Affect The Rate of Photosynthesis
Human Effects

2. The Human Effects
There are several ways humans can affect plant distribution and growth. These are the different ways…
Use of Fertilisers
Monoculturing
Trampling on Plants
Deforestation
Overharvesting
Air Pollution

3. Trampling of Plants - Growth
Trampling can damage growing plants in that if a leaf comes off the plant, the amount of Photosynthesis that can take place in the plant is decreased as it absorbs the sunlight.
Trampling can also damage the soil, this has long term affects, which as affecting the air and water availability in the soil because if the soil is compacted, rain will just sit on top of the soil rather than going down into the soil, this can lead to drought in extreme cases.

4. Trampling of Plants - Distribution
The compaction of the soil can also lead to reduced germination in the plants. Most plants and flowers rely on insects such as bees to carry pollen to other plant, if the plant is crushed and damaged, a bee will not be able to get any pollen from the plant.

5. Deforestation - Growth
Deforestation is when a forest or part of a forest is cut down by humans for use of the wood or for more land. For example, the background picture of this slide is of a rainforest in Sumatra, this area has been deforested because coal and copper companies have taken the land in order to mine in the area.
Human activity has reduced the global forest area from 14% to 6%.
Growth in deforested areas is practically impossible because the land gets damaged during the process and is no longer suitable for plants.

6. Deforestation - Distribution
The deforested land is no longer suitable for plants after large vehicles have driven over the soil and compressed it, also large areas would take an extremely long time to get back to how they were. Many habitats are destroyed during deforestation, which leads to extremely low biodiversity, or practically none at all.

7. Monoculturing - Growth
Monoculturing affects plant growth because growing the same plant in the soil over and over again will ruin the soil; One type of plant will take the required nutrients out of the soil and if you repeat this process, those nutrients will eventually be depleted and the plants will no longer grow, or at least grow much smaller.
Farmers do this in their farms, and they can combat this by growing different plants in the soil year round.

8. Monoculturing - Distribution
Distribution due to monoculturing is much lower because plants in monocultured land are extremely close, therefore plants cannot be distributed because there is no room for them to grow.
If there is a type of fungi that kills the plants in the monoculture, the fungi will spread though the entire field and kill all the plants.

9. Overharvesting - Growth
Overharvesting effectively stops plants growing because repeatedly using the same soil will take all the nutrients out of the soil and make the soil useless because the plants won’t get what they need for growth.
Soil losing nutrients due to overharvesting is known as “Soil Degradation”.

10. Overharvesting - Distribution
Plants will die and will be unable to distribute, furthermore, the soil will be unable to support plants being distributed into the land until the soil has replenished.