Filed under: Plant physiology
Over at News@nature, Mike Hopkin reports from the Ecological Society of America’s meeting in San Jose on research into tropical forest growth rates. Looking at plots in Panama and Malaysia, the researchers found that increases in mean daily minimum temperature over a couple of decades correlated with decreases in growth rates. They associate this with lower net photosynthetic activity.
The team, led by Harvard’s Ken Feeley, suggests that if this sort of effect were repeated in bigger rainforests (most of which have only experienced marginal warming to date, as I understand it) then what are now stable stores of carbon would become net sources as theworld heats up. This is obviously a considerably less optimistic scenario than the possibility that carbon-dioxide fertilisation would make them sinks. It would presumably make the net effect of the increase in soil respiration that Peter Cox and others always stress (Nature paper from 2000) an even worse problem.
It’s not a dead cert that the change is due to temperature — the paper (published in Ecology Letters) seems to suggest that increased cloudiness could be playing a role. And there could be internal botanical changes too — maybe the lianas are doing more damage? But all in all it doesn’t sound good.
Mike is blogging the conference on the newsblog.
Cross posted at Climate Feedback
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