plants and global climate change Flashcards
what is photosynthesis
the process where light enegry is tuned into biochemical enegry used to drive the assimilation of low energy inorganic carbon to high energy organic biochemical s
what is climate change
a large-scale, long-term shift in the planets weather patterns or average temperatures
how is climate measured
by assessing the variation in patterns of temp, humidity, atmospheric pressures, wind and precipitation
what are some consequences of climate change
1) loss of sea ice
2) changes in weather patterns
3) increased flood and rainfall
4) extreme weather events e.g. hurricanes and forest fires
5) droughts
6) changes in crop yeild
how does climate change cause the loss of sea ice
decreased ice = less albedo effect so less ice reflecting sunloght so more absorbed and radiated out has heat so planet gets warmer and more ice melts
what is el nino
refers to large-scale ocean-atmospheric climate interactions linked to periodic warming in sea surface temps
what was hurricane maria
a category 5 hurricane which devistated Dominica, U.S virgin islands and puerto rico in sep 2017
what happens to c3 plants at low carbon dioxide levels
photorespiration occurs as stomata close and oxygen is added to RuBP instead
what limits photosynthesis under high light conditions
the carboxylation reaction
what is photo-oxidation
often follows photoinhibiton where bleaching of photosynthetic pigments occurs
what are ice cores
cores of ice containing carbon dioxide gas bubbles which provide data on past climatic conditions
what are some theoretical considerations of the effect of increased co2 on vegetation
1) increased rate of net photosynthesis in at least short term due to co2 acting as a substrate for photosynthesis and decreased photorespiration
2) increased biomass
3) increased water use efficiency
outline some experimental observations in increasing c02 on vegetatino
1) some species show a negative response in long term observations
2) there is a large variation and inter-specific differences
what affect does carbon dioxide have on water use efficiency
1) decreased stomata; aperture
2) decreased number of stomata per unit area
what did studies conducted by woodward show on the effect of co2 on water use efficiency
1) average reduction in stomatal density by 14,2%
2) stomatal conductance decreased
3) co2 enrichment will increase water use efficiency by decreasing transpiration
