biomes and forests Flashcards
what is meant by the term biome
global scale ecosystem
state two resources people might obtain from the biosphere
food traditional medicines building materials wood fuels water
three features of a rainforest
- very tall trees
- canopy layer
- layered or stratified forest structure
- buttress roots
define the term abiotic
non-living component of an ecosystem
state two good or services provided by the tropical rainforests
medicines
timber/wood
food
describe one benefit of deforestation
many of the goods are exported - eg. timber - stronger currency
crops grown on deforested land
outline one reason for the distribution of tropical rainforests
- areas of high rainfall - supporting rapid growth - dense vegetation
- close to equator - high temp - allowing high NET PRIMARY PRODUCTIVITY
explain one way the biosphere can maintain soil health
leaf fall leads to litter which decays into humus - which provides nutrients for plant growth
source of organisms, such as earthworms, which improve soil quality and structure
explain why Peru has high levels of biodiversity
- hot / wet tropical climate = ideal for growth of tropical forests which have high biodiversity = the complex stratification of the rainforest ensures a wide range of ecological niches
explain two ways in which plants have adapted to living in tropical climates
- drip tips = remove excellent water in conditions of over 2000 mm of precipitation
- buttress roots = stabilises the trees as they increase in height
- waxy leaves = to stop excess water infiltrating into leaf and rotting
explain why there are differences in the nutrient cycles in deciduous temperate forest and TRF
BIOMASS STORE - bigger in TRF = as more nutrients are held in the vegetation store because of high biodiversity in the ecosystem = so there is more available nutrients = as there is more photosynthesis, meaning a greater amount of productivity
SOIL STORE - smaller in TRF = as the nutrient uptake is higher in TRF and there is a greater amount of leaching due to more rainfall in TRF 2000 mm
LITTER STORE - smaller in TRF = as rate of decomposition s much greater because of the hight humidity
explain why there are differences in the climate between deciduous woodland and tropical rainforest
SEASONAL VARIATIONS = deciduous woodlands are exposed to both warm and cold air masses during a year = which results in a greater seasonal variation / four distinct seasons
TEMP = higher in the TRF because they are located near the equator = where there is more direct sunlight hitting the land and sea = however deciduous woodlands have lower temps because they are found at higher altitudes further away from the equator = where the sing light is more dispersed
RAINFALL = higher in TRFs because there are higher temps = increases evaporation rates = warmer air can hold more water vapour
explain one reason why tropical rainforests have a high biodiversity
oldest biome on earth planet = and has had more time to develop a greater species diversity
high rainfall/ temperature = produces good conditions for growth
explain two causes of deforestation in tropical forests
- trees are cleared to grow crops / cattle ranching = as population increases or to export
- trees are cleared for fuel / firewood = as demand rises due to population growth
- trees are cleared for timber = as rates of urbanisation grow
suggest one reason why the annual rate of deforestation has fallen since early 2000s
- the rate of deforestation has fallen because of increased protection of the forests by the government = this means that clear felling has been banned in some areas = and loggers will face significant fines or imprisonment if they dont follow this
- the rate of deforestation has fallen because of increased importance of ecotourism = this means job can be created without damaging the forest = which brings money into local economy and means fewer trees need to be cut down
