Topic 8a - Rainforetss

Question 1

How do the abiotic and biotic factors interact in a rainforest biome?

Answer 1

• wet and warm climate so plants grow quickly/ protect forest wall/ keep soil together
• less wind near forest floor = rely on bees for pollination (symbiotic relationship)
• lots of epiphytes get access to light by growing high on other plants (no access to nutrients so depend on rain)
• knock on effects = less trees = less CO2 absorbed = worse climate

Question 2

Describe the plants in rainforest biome

Answer 2

• adapted to hot, wet climate
• thick waxy leaves with pointed tips ( rain falls) and waxy repels rain
• smooth bark to protect trunk from cold temp as water runs off easily
• climbing plants use tree munis to climb up to sunlight
• plants drop leaves all year round so can grow all year

Question 3

Describe the plant layers (stratified layers)

Answer 3

• 0-10m = shrub layer = dark, shrubs have large broad leaves to absorb as much sunlight as they can
• 10 - 20m = younger trees which survive in breaks in canopy where light gets through
• 20 - 30m = continuous layer of trees which shade the forest and dense layer of leaves
• 30-40m = tallest trees, straight trunks, leaves only at top, buttress roots

Question 4

Describe the animals in a rainforest biome

Answer 4

• monkey spend times on canopy so have strong limbs
• flaps of skin (squirrels) to glide between trees or suction cups for climbing
• camouflages (leaf tailed geckos)
• nocturnal (sloths) = save energy
• low levels of light on rainforest floor so anteaters have sharp sense of smell and heating (detect predators without seeing them)
• swim (Jaguars) - can cross river channels

Question 5

Describe the nutrient cycles in a rainforest biome

Answer 5

• nutrients cycled quickly as trees are every green so dead materials and leaves fall all yr
• warm and moist climate so fungi and bacteria decompose quickly
• nutrients released are soluble so soaked up in soil
• dense vegetation and rapid plant growth = nutrients quickly taken up by plant roots
• biomass = biggest, then soil, then leaching

Question 6

Describe the biodiversity in a rainforest biome

Answer 6

High

• biome has been around for a long time - enough time for adaptation
• layered = lots of habitats = many species
• stable environment and high nutrient cycling = no change so plants specialise
• isolated (not affected by human biodiversity)

Question 7

What are the food webs in rainforest like?

Answer 7

Complex

Many animals are primary and secondary consumers

Question 8

Climate of rainforests

Answer 8

• 60mm of rain each month (3m/yr)
• temp - 26-32 degrees
• heaviest rainfall in Jan and closest to equator
• now less rainfall, forest fires, leaching, food supplies drying up, droughts due to climate change

Question 9

Explain what Costa Rica did to battle deforestation

Answer 9

• 30% of forest gone
• forest restoration through CFP where money to owners that replanted trees on land and get certificate which can be traded for cash/ pay tax as part of PES scheme (increased by 7%)
• ecotourism and sustainable forestry (intercropping)

Question 10

What are the challenges of sustainable forest management

Answer 10

• more money can be made in short term exploration of forest for HEP, mineral extraction, logging and farming than conservation
• more money in growing pineapples/ clearing forests than PES schemes
• but ecotourism and sustainable farming has better income in the long term
• ecotourism only works well with small numbers of visitors, which restricts overall income