View stunning SlideShares in full-screen with the new iOS app!Introducing SlideShare for AndroidExplore all your favorite topics in the SlideShare appGet the SlideShare app to Save for Later — even offline
View stunning SlideShares in full-screen with the new Android app!View stunning SlideShares in full-screen with the new iOS app!
The CO 2 ‘fertilisation effect’ : c rops grown under elevated CO 2 exhibit enhanced growth and yields
C 3 plants (crops, grasses, trees, shrubs) are particularly responsive
C 4 crops (maize, sugarcane, sorghum) are less sensitive
Changes occur: in chemical composition (C:N ratios), plant defences, biomass , leaf area, canopy structure, abundance and distribution
Big increase in fixation of C into organic matter (I.e. plant growth) but will it be sustained?
Plant defenses decrease (↓) as CO 2 levels increase Soybeans grown at elevated CO 2 levels attract more pests - than plants grown at current CO 2 levels Experiments at high CO 2 levels Photo by E Deluccia
Free-Air CO 2 Enrichment experiments - enrich the atmosphere around part of a terrestrial ecosystem with controlled amounts of CO 2
Average northerly increase of 3.5° latitude (= 400 km)
In total, 99.4% of the area of potato production in GB would be vulnerable
Climate change and weeds – upsetting the balance with crops
Any direct or indirect effect of climate change that differentially effects the growth and fitness of weeds, relative to crops, will alter weed-crop interactions –sometimes to the detriment of the crop, sometimes to it benefit*
Many of the ‘worst’ weeds are C 4 plants (which may benefit from temperature and low dryness)
Most crops are C 3 plants (which may benefit from in CO 2 )
*D T Patterson (1995) Weeds in a Changing Climate
Implications of climate change for pest, weed and disease management
More pests and diseases but possibly off-set by increased yields?
New crops with new niches for invasive pests and diseases
Increased pesticide use and possible loss of function?