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natural and human impacts - Coggle Diagram
natural and human impacts
change due to natural events
other natural events, like bushfires, drought, and flooding, also have huge impacts on ecosystems
season changes affect organisms of a community because they are influenced by abiotic factors such as changes in rainfall, temperature and the amount of available light
natural events affect ecosystems
bushfires
bushfires burn through natural vegetation, plantations and towns
some are accidently lit by humans while other are caused by natural processes like lightning
natural fires have been affecting ecosystems in Australia for over 40 million years
bushfires promote germination of many plant species
after a fire, much of the bush regenerates through germination
many plants have adapted due to bush fires
epicormic growth: growth of new shoots from stems of trees and shrubs after fire
droughts
Australia suffers regular droughts, often lasting five years of more
can change ecosystems by increasing the death rate of plants and animals
example: river red gums need require regular water and will die if the rivers they grown next to dry up
death of the plants lead to less resources for the neighbouring animals that use those plants for either food or shelter. this causing those animals to migrate to the other locations in search for that plant
this can cause whole ecosystems to die
flooding
flooding is a result of heavy rains
where rivers overflow their banks to cover usually dry areas of land
flooding can dramatically affect natural ecosystems and can cause high death rates of native animals and plants
plants drown due to lack of oxygen at their roots and animals die from drowning from the lack of oxygen to breathe
the increased rainfall in drier places can lead to an "explosion of life." refers to how plants and animals adapted to reproduce rapidly to take advantage of the extra food and favourable living conditions
change due to human impact
humans can affect the ecosystem in negative ways
clearing land, destroying places where species live, disposing toxic wastes into natural ecosystem and other similar human actions are negative impacts in a natural ecosystem
however, in the aim to make a positive contribution to the health of an ecosystem humans are trying to minimise the negative impacts
habitat destruction
damage and harm done to the environmental factors an organism depends on for survival
mining, land clearing and logging
although the damages aren't permanent and the ecosystems can be repaired if there is enough knowledge of the environment and the available resources
due to agricultural development, the number of animals have declined
although some animals' population have increased because of the increased food supply
like kangaroos, emus and locusts
introduced species
feral animals are introduced animals who have established in the wild
the wildlife has been experiencing devastating affects due to the feral cats and foxes killing the native animals
animals and plants brought to Australia from other courtiers
fewer native animals can survive due to feral animals like rabbits, cats, donkeys, horses camels, mice, rats, goats and pigs competing with the native animals for food and shelter
many introduced plants have turned into weeds, which now successfully compete with the native animals for available resources
chemical pesticides
insecticides are chemicals that kills insects
some turned out to be dangerous to other animals as wells as insects
DDT is an example of this, when it enters the food chains because it carries water and wind onto land and into lakes and oceans. the chemicals that were absorbed by the plants and animals that live in the water
waterways carry DDT drifts to lakes and oceans
passes into cells and accumulates there
from 1970s research it was discovered that presence of DDR was found in all organisms in the food chain
the accumulated DDT had serious effects on some birds especially those further down the food chain
DDT also accumulates in humans especially in breast milk
having links to diabetes, reproduction problems, hormonal disruption and cancer
biological control: the use of natural enemies against the pest species and is a more effective alternative to insecticides
chemical pollution
when chemicals escape into the environment which can cause damage to the ecosystem.
like plastic which is becoming a more and more increasing problem in the ocean
many of those plastics which can contain poisonous chemicals, like lead, are digested by organisms. which can prove deadly for those species
global warming: the increase in the temperature of Earth's atmosphere
the rising sea levels caused by the increase of temperature melting ice caps can cause other chemicals getting into our environment, like oil spills from shops
over cropping
refers to killing more animals that can be replaced by the normal breeding cycle
results in a decrease in the population
the population of the blue whale in the 1980s was only five percent of the population earlier that century