The scientific phenomena that could have big impact on crops
VAPOUR pressure deficit may be a little-known term, but the impact of this climatic phenomena could be drastic for those in the agricultural sector.
The phenomena have existed in scientific circles for a while, but with the increase of climate change in recent years, so too has evidence of the deficit.
Associate Professor Lucas Cernusak, from James Cook University, said the vapour pressure deficit impact was commonly seen on plants and crops.
"It's a measure of the water vapour in the air, sort of how thirsty the atmosphere is," Dr Cernusak said.
"It's something that's well known for a long time, certainly the biophysics and the way plants interact with water vapour, but it's recently becoming more recognised that as the climate warms the vapour pressure deficit increases and that impacts plants."
This could potentially have wide ranging impacts for the agricultural sector on the Northern Rivers, especially for farmers whose livelihoods are centred on crops.
"What it would tend to do is to slow plant or crop growth, so a higher-pressure deficit or drier air will in general cause plants to close their stoma to slow the rate of evaporation from leaves," Dr Cernusak said.
"When the stomata close a little that restricts the diffusion of carbon dioxide into the leaf for photosynthesis so it slows down photosynthesis and we'd expect it'd slow plant growth and in terms of crops, it could decrease yield.
"The interesting thing for Australia is that the north is becoming wetter and there's a decrease in vapour pressure deficit."
According to Dr Cernusak's latest research, while the deficit is closely linked to climate change, but it may also be linked to the temperature deficit.
"It's hard to tease apart from impacts of temperature and atmospheric Co2 concentration but it would be nice to understand the vapour pressure deficit in isolation away from those other impacts," he said.
This link to climate change does mean an increase to the vapour pressure deficit is preventable, if climate change is slowed in the coming years.
"Definitely the best solution would be to decrease greenhouse gas emissions and slow or halt global warming so that's the big societal challenge that we aren't easily able to meet," Dr Cernusak said.