Tropical Region Biome – Tropical Equatorial Rainforest
Location and Distribution:
Mostly centred around 10° North and South of the Equator, bound by the tropics. Examples include Amazon, Central Africa, Malaysia, Indonesia and Guinea.
Climate:
High average temperature of around 26-27°C, owing to location about the tropics. The seasonal temperature range low (only around 1-2°C), but the diurnal range high: around 10-15°C. Rainfall is also high: greater than 2000mm annually. The majority of this is intense, convectional rainfall, occurring over 250 days a year. This leads to high humidity levels, which are often 100% at ground level. These factors all contribute to a year-round growing season.
Mostly centred around 10° North and South of the Equator, bound by the tropics. Examples include Amazon, Central Africa, Malaysia, Indonesia and Guinea.
Climate:
High average temperature of around 26-27°C, owing to location about the tropics. The seasonal temperature range low (only around 1-2°C), but the diurnal range high: around 10-15°C. Rainfall is also high: greater than 2000mm annually. The majority of this is intense, convectional rainfall, occurring over 250 days a year. This leads to high humidity levels, which are often 100% at ground level. These factors all contribute to a year-round growing season.
Vegetation:
Evergreen vegetation takes advantage of year-round growing season. Tropical Rainforests have defined stratification in their vertical layers; the shape of the plant crowns vary with strata to gain maximum light potential. The year-long growing seasons and high rainfall means the biome is highly productive and consequently has high biomass. They are also diverse ecosystems with up to 200 species per hectare and have half of world’s floral and fauna species. Light is the main limiting factor in Tropical Rainforests. The further from equator, water becomes the issue.
Adaptions:
· Epiphytes: species that live on trees and use them for their support due to competition for light
· Sacraphytes: species that live on and take nutrients form the host plant
· Broad leaves to catch water and drip tips and waxy leaves to get water to the roots
· Taller, thinner species to get light
· Deep root system to anchor and try to draw up nutrients and water
· Evergreen to grown all year round
Evergreen vegetation takes advantage of year-round growing season. Tropical Rainforests have defined stratification in their vertical layers; the shape of the plant crowns vary with strata to gain maximum light potential. The year-long growing seasons and high rainfall means the biome is highly productive and consequently has high biomass. They are also diverse ecosystems with up to 200 species per hectare and have half of world’s floral and fauna species. Light is the main limiting factor in Tropical Rainforests. The further from equator, water becomes the issue.
Adaptions:
· Epiphytes: species that live on trees and use them for their support due to competition for light
· Sacraphytes: species that live on and take nutrients form the host plant
· Broad leaves to catch water and drip tips and waxy leaves to get water to the roots
· Taller, thinner species to get light
· Deep root system to anchor and try to draw up nutrients and water
· Evergreen to grown all year round
Soils:
Known as Tropical Latosols or Tropical Red Earths. These are deep soils, yet they have a thin O Horizon: continuous leaf litter is turned over at 1% per day due to demand of nutrients. Rocks are well weathered, so little minerals input from there therefore relying on leaf litter. Accumulations of iron and aluminium give red colours. High rainfall and runoff leads to nutrient leaching as well as high uptake, therefore soils are only 4% fertile. Leaching leads to loss of nutrients such as N, Ca, Mg and K.
Known as Tropical Latosols or Tropical Red Earths. These are deep soils, yet they have a thin O Horizon: continuous leaf litter is turned over at 1% per day due to demand of nutrients. Rocks are well weathered, so little minerals input from there therefore relying on leaf litter. Accumulations of iron and aluminium give red colours. High rainfall and runoff leads to nutrient leaching as well as high uptake, therefore soils are only 4% fertile. Leaching leads to loss of nutrients such as N, Ca, Mg and K.
Nutrient Cycle:
Very little fertility in the soil: nutrients are cycled quickly and are held mostly in the biomass, with a big transfer from the litter to the soil, and then into the biomass. What would the nutrient cycle look like for a tropical rainforest?
Human Impact:
A population of 200 million people live in tropical rainforests across the world. This coincides with an annual loss of around 40 million acres of forest. In 1994, global coverage had halved from its peak to 6%. Main conflicts include cattle ranching, banana, coffee and rubber plantations, logging, farming and mining.
Very little fertility in the soil: nutrients are cycled quickly and are held mostly in the biomass, with a big transfer from the litter to the soil, and then into the biomass. What would the nutrient cycle look like for a tropical rainforest?
Human Impact:
A population of 200 million people live in tropical rainforests across the world. This coincides with an annual loss of around 40 million acres of forest. In 1994, global coverage had halved from its peak to 6%. Main conflicts include cattle ranching, banana, coffee and rubber plantations, logging, farming and mining.