Assess the relative importance of human and physical factors influencing levels of biodiversity (15 Marks)

There are a range of human factors which affect the levels of biodiversity in an area in positive and negative ways. The way in which people use resources can have a damaging effect on the levels of biodiversity as trees are cut down for wood or paper; in some places this is leading to high levels of deforestation. Particularly in areas such as the tropical rainforest, this can lead to the destruction of habitats and so put many endemic species at risk. Also, in many areas there are poachers who put many species at risk of extinction as they can gain wealth by hunting them.
In more built up areas, there is likely to be much lower biodiversity as concrete is built over where plants may have previously grown and areas with the highest biodiversity are relatively undisturbed. Due to an increasing population, many more areas are becoming built up by the process of urbanisation. This gives local species less opportunity to continue or to develop and so lowering the level of biodiversity of the area.
In a less direct way, biodiversity can be affected by humans as pollution is created, affecting air quality and contaminating water sources. Pollution can make an area more hostile to other species living in the area which can affect the population of them in a negative way. Particularly in cases of contaminated water sources, the pollution can be toxic to plant or animal species and cause a decline in the population which can have a long term effect on the species.
Whilst reasons stated above have a negative impact on biodiversity, humans can allow affect these levels in a positive way. Through conservation projects, such as The National Trust, humans can protect areas from factors which cause depletion in biodiversity. This method of conservation can prevent the destruction of endemic species and lower the chances of extinction; through this, species are given more opportunity to continue and to develop.
If an endemic species is close to extinction, humans can play a part in helping it to continue. This can happen by the restoration of an area whereby the area is cleared up in order to make it more appropriate for species to develop. Also, with animals such as the Giant Panda, breeding programs can be set up in zoos which promote the continuation of the species in question.
There are also a number of physical factors which impact the levels of biodiversity in an area. The isolation of an area, such as the small islands around the Philippines, can increase the levels of biodiversity. Being separate to other areas, more endemic species develop. Furthermore, there is less risk of alien species entering the ecosystem which would cause a threat through competition with local species.
In some, mainly large, areas there are a higher range of altitudes. This would lead to a wider range of climates and conditions. Species are particularly adapted to the area they live in and so an area with various climates would have more species within it due to the adaptation to the living conditions. Also, at high altitudes, there is less likely to be human disturbance as the conditions are hostile to those who are not adapted for it.
The overall climate of an area can have an effect on the levels of biodiversity in an area. Ideal conditions for high biodiversity would involve a lot of rain and high temperatures as they produce higher productivity; this is more commonly found around the tropics. Conditions which are unlike these would lead to lower levels of biodiversity.
Natural disasters can have a negative effect on biodiversity levels in an area. Disasters can destroy some species; for example, in Australia there are many droughts and fires which some animal and plant species would not be able to survive. This would have a long term effect on the population of these species and so, on the biodiversity of the area.
Both human and physical factors can largely affect the biodiversity levels of an area. They are both capable of causing equal impacts. However, whilst human factors could, theoretically be controlled, physical factors are somewhat more unpredictable and so it is less possible to compensate for the negative effects. Human factors are more capable of causing much more immediate action on the levels of biodiversity and so may have a more significant positive effect.

Mesoamerica Hotspot Original Extent (km²) | 1,130,019 | Hotspot Vegetation Remaining (km²) | 226,004 | Endemic Plant Species | 2,941 | Endemic Threatened Birds | 31 | Endemic Threatened Mammals | 29 | Endemic Threatened Amphibians | 232 | Extinct Species† | 7 | Human Population Density (people/km²) | 72 | Area Protected (km²) | 142,103 | Area Protected (km²) in Categories I-IV* | 63,902 |
†Recorded extinctions since 1500. *Categories I-IV afford higher levels of protection.

Madagascar Hotspot Original Extent (km²) | 600,461 | Hotspot Vegetation Remaining (km²) | 60,046 | Endemic Plant Species | 11,600 | Endemic Threatened Birds | 57 | Endemic Threatened Mammals | 51 | Endemic Threatened Amphibians | 61 | Extinct Species† | 45 | Human Population Density (people/km²) | 32 | Area Protected (km²) | 18,482 | Area Protected (km²) in Categories I-IV* | 14,664 |
†Recorded extinctions since 1500. *Categories I-IV afford higher levels of protection.

Himalayas Hotspot Original Extent (km²) | 741,706 | Hotspot Vegetation Remaining (km²) | 185,427 | Endemic Plant Species | 3,160 | Endemic Threatened Birds | 8 | Endemic Threatened Mammals | 4 | Endemic Threatened Amphibians | 4 | Extinct Species† | 0 | Human Population Density (people/km²) | 123 | Area Protected (km²) | 112,578 | Area Protected (km²) in Categories I-IV* | 77,739 |
†Recorded extinctions since 1500. *Categories I-IV afford higher levels of protection.