Geography Flashcards
what is an ecosystem
a community of plants and animals that interact with each other and their physical environment
what are biotic elements
the living elements of an ecosystem
what are abiotic elements
the non living elements of an ecosystem
examples small scale ecosystems
- hedgerows
- ponds
- woods
examples global ecosystems
- rainforests
-hot deserts - tundras
what are global ecosystems also called
biomes
what is a habitat
the place where an organism lives. Must provide food, shelter and a place to reproduce
what does a food chain show
the feeding relationship between organisms
what do arrows represent in a food chain
the flow of energy
what is first in a food chain
a producer which uses photosynthesis to create food
what are consumers
organisms that directly depend on producers for food. Further categorised as herbivores, carnivores, omnivores and parasites
what are decomposers
organisms that break down dead matter and decay for nutrition
what does a food web show
lots of food chains within an ecosystem and how they overlap
what are nutrients
foods that are used by plants/ animals to grow
what are the 2 main sources of nutrients
rainwater (washes chemicals out of atmosphere) and weathered rock (releases nutrients into the soil)
what is a biome
a large scale ecosystem. They are defined by factors such as climate, soils and vegetation. The world’s major biomes include rainforest, desert, savanna grassland and tundra
what is the tropic of cancer
northernmost latitude at which the sun can be directly overhead (23.4 degrees north)
what is the tropic of capricorn
southernmost latitude where the sun can be directly overhead (23.4 degrees south)
where are tropical rainforests mainly found
between the Tropic of Cancer and Capricorn
what factors affect the distribution of global biomes
altitude- increase in height above sea level leads to decrease in temperature
ocean currents- cold ocean currents create dry conditions from lack of evaporation
mountain ranges- force air upwards leading to relief rainfall over mountainous areas causing dry land on the other side (rain shadow)
latitude- temperatures and sunshine decrease with distance from equator
precipitation- areas of high pressure- low rainfall, areas of low pressure- high rainfall
why does the amount of energy decrease as you move up the food chain
much of the energy from prey is lost through excretion, energy is being used for important functions (e.g. respiration, digestion)
what is biodiversity
the variety of living species on Earth
what does bad land management lead to
drought, soil erosion and desertification
how do human activities affect ecosystems
factors such as deforestation, overgrazing and overfarming reduce the productivity of land meaning it can no longer support plant growth. This results in difficulties to farm, creating economic challenges and erodes the soil on which primary producers grow, coincidently affecting food sources of dependant consumers
what is the climate of TRFs like
-very warm as sun is directly overhead at the equator for a longer period of time meaning less radiation is absorbed and is concentrated in a smaller area at the equator
what is the soil of TRFs like
-infertile soil
-thin layer of fertile soil at the surface where dead leaves decompose
-nutrient cycling is rapid due to humidity which helps dead matter decompose
-nutrients are quickly washed out of soil from heavy rainfall
what is biodiversity like in TRFs
-warm and wet climate provides perfect conditions for plant growth
-wide range of plant species support different animals
-adapted species
what are the layers of the TRFs
emergent
canopy
under canopy
forest floor
why is the TRF important
. Life support systems:
- regulate the atmosphere by absorbing CO2 through photosynthesis and releasing oxygen
- rapid leaf fall/ decomposition creates fertile soil which supports organisms and agriculture
- trees store/release water through evapotranspiration which contributes to consistent rainfall
. Goods:
-food sources
-cash crops
- medicines
-raw materials
. Crucial habitats
. Reduce Climate change
what is an adaptation
a change is structure/function to improve chances of survival in particular environments
why must organisms in TRFs adapt
organisms must adapt/develop specialised traits to compete for environmental resources and protect themselves from predators
what is deforestation caused by
agriculture, logging and infrastructure projects
why is deforestation an issue
leads to habitat loss, soil erosion and ecosystem disruption
why is climate change an issue
rising temperatures and changing rainfall patterns increase drought, forest fires and affect biodiversity
why are illegal activities an issue
illegal logging- strips forest of valuable trees
illegal mining- pollutes rivers
poaching- threatens species
why are threats to indigenous communities an issue
loss of culture
exposure to diseases
why are weak environmental policies an issue
prioritise economic development over conservation, allow illegal activities to continue, insufficient funding for conservation
what is arid
very low rainfall, such as deserts (many are hot, causing water to evaporate faster than it can be replaced)
what is high pressure
descending air that produces no clouds/rain
what is altitude
height of object from sea level
what is latitude
north-south position of a point on the Earth’s surface
what is rain shadow
reduced rainfall behind a mountainous region, on the side facing away from prevailing winds (leeward side)
what is the hadley cell
the neverending cycle of air rising from the Equator
where are hot deserts generally found
around the Tropics of Cancer and Capricorn, between 15 and 30 degrees North and South of the Equator
what are conditions like in hot deserts
very dry areas with a significant diurnal temperature range of around 45 degrees celcius on the high end
how does atmospheric circulation work
-air between Hadley and Ferrell cells sinks
-air warms as it sinks
-more water vapour is evaporated into the air that can condense
-cloud formation is limited
-areas are dry as a result
what is transpiration
moisture given off by plants through their leaves
what are xerophytes
drought-resistant, small leaves that reduce transpiration
what is irrigation
redirecting/channelling water for use elsewhere
how is an arid desert environment formed
air cools and condenses as it rises, meaning the water vapour becomes liquid and results in precipitation. The air is now dry as it has lost its moisture and descends
what is groundwater
water that exists underground beneath the land surface
what is desertification
land becomes drier and degraded as a result of climate change/human activities
what is bottom up technology
local scale projects that aim to help a small community develop
what is ecotourism
type of nature based tourism that emphasises reducing your environmental impact
what is soil erosion
gradual process from impact of water/human activities detatching and removing soil particles, causing the soil to deteriorate
what is nutrient cycling
the cycling of minerals from soil and water up through the food chain before returning to the soil and water
