lec 25 land transformation global change

land use change

conversion of existing natural ecosystems to other landscape forms

largest terrestrial biome is now

agirculture (12% for crops, 24% for pasture)

impact of deforestation on CO2

loss of a carbon sink, crops do not sequester as much and it gets returned faster, respiration from animals

impact of deforestation on hydrological cycle

less transpiration decreases cloud cover and the “flying river”, which leads to greater forest loss

slash and burn agriculture

burning woods and planting crops in the nutritious ashes, only viable for a year or two before needing to burn more area

deforestation and albedo

crops raise it, surface becomes more reflective

forests have the _ terrestrial biodiversity

highest

grasslands are the most _ but better for _

endangered biome; carbon storage

human impacts on wetlands

have been drained for agriculture or used for rice, holding less water for a shorter amount of time and losing soil’s organic matter and biodiversity

urban effects

urban heat island due to lower albedo, untrapped runoff and flooding due to non-porous surfaces

surface mining

dramatic alteration of landscapes and their morphology, loss of habitat

mountaintop removal

removal of all biomass and severe geological modification

further mining impacts

chemical contamination, further toxic chemicals needed to process minerals that are improperly stored or disposed of

issues with reforestation

does not always restore species richness, genetic variation, and symbiotic relationships