Human Impacts on Vegetation Flashcards
are human actions that impact the environment. These activities can include:
Anthropogenic activities
The clearing of land for other uses, such as construction or agriculture
Deforestation
The development of cities, which destroys natural habitats and reduces green spaces
Urbanization
The release of harmful substances into the environment, such as from industrial processes
Pollution
The variation in average climate parameters, caused by the release of greenhouse gases into the atmosphere
Climate change
The excessive use of non-renewable resources, such as fossil fuels
Overexploitation of natural resources
The intentional release of non-native species into an environment
Introduction of invasive species
The cultivation of crops and raising of animals to provide food and materials
Agriculture
the most potent cause of change.
deforestation
T or F: Humans have done much to transform the vegetation cover of the Earth.
True
: those that develop in the absence of human activities
Natural habitats
those produced by sporadic, yet incomplete, disturbances; for example, the cutting of a forest, burning and the non-intensive grazing of
natural grassland.
Degraded habitats
where disturbance is sustained but here there is no intentional substitution of vegetation. Roadsides are an example of a ruderal habitat.
Ruderal habitats
when constant disturbance is accompanied by the intentional introduction of plants.
Cultivated habitats
which are developed when humans modify the ambient climate and soil, as in greenhouse cultivation
Artificial habitats
Promote the growth of certain fire-adapted plant species, to improve grazing land for domestic animals or to attract them
Ecological benefits
- fire has been used to clear land for agriculture by burning existing vegetation, a practice known as
“slash and burn”
– through the practice of prescribed burning, reducing underbrush cover, preventing large-scale wildfires, promote regeneration of certain tree species
Forest management
– to manage landscapes for hunting, agriculture and maintaining biodiversity
Cultural practices
may lead to loss of habitat for wildlife and disruption of ecological balance
Habitat destruction
reduce soil fertility and increase risk of erosion
Soil erosion
could significantly impact air quality and human health
Air quality issues
should only be conducted under specific weather conditions to minimize risk of uncontrolled spread
Weather conditions
training and expertise are crucial to manage fire safely and effectively.
Trained personnel
requiring permits and trained personnel
Regulations
to assess ecological impact and adjust management strategies.
Monitoring and adaptation
The consequences of tropical deforestation.
1 Reduced biological diversity, habitat loss
2 Changes in local and regional environments
3 Changes in global environments – climate change
4 Cultural impact
to reduce the mounting pressures on landless peasants caused by inequalities in land ownership
land reform
by setting aside areas of rain forest as National Parks or nature reserves;
conservation of natural resources
while protecting the habitat, allows a type and level
of economic activity that can be sustained into the future with minimum damage to people or forest
sustainable development
swaps whereby debt-ridden tropical countries set a monetary value on their ecological capital assets (in this case forests) and literally trade them for their international financial debt;
‘debt-for-nature’
may increase the productivity of wild pastures
Light grazing
can kill plants or lead to a marked reduction in their level of photosynthesis
Heavy grazing
Hunting and killing animals for profit
Poaching
Gaseous forms such as sulfur dioxide, most oxides of nitrogen and carbon monoxide (from industries); ozone and products of photochemical reactions, are formed as a consequence of subsequent chemical processes in the atmosphere (involving the primary pollutants and other agents such as sunlight).
Air pollutants exist in gaseous or particulate forms
or liquid-suspended droplets (e.g. dust, smoke and aerosolic salts), and contain a wide range of insoluble components (e.g. quartz) and of soluble components
(e.g. various common cations, together with chloride, sulfate and nitrate)
Particulate pollutants consist of very small solid
active shedding leaves while still green, with no indication of disease; shedding of whole green shoots, especially in spruce; altered branching habit; altered morphology of leaves.
Abnormal growth symptoms
altered water balance; increased incidence of wet wood disease.
Water-stress symptoms
discoloration and loss of needles and leaves; loss of feeder-root biomass (especially in conifers); decreased annual increment (width of growth rings); premature ageing of older needles in conifers; increased susceptibility to secondary root and foliar pathogens; death of herbaceous vegetation beneath affected trees; prodigious production of lichens on affected trees; death of affected trees.
Growth-decreasing symptoms
T or F: The introduction of pests, can also lead to a decrease in the range and numbers of a particular species
True
