Changing Climate, Shifting Crops - Kirsten Hannam AAFC
•
0 j'aime•36 vues
The effects of climate change are being felt across British Columbia. Given that climate is the most important determinant of crop suitability for a given location, climatic change has and will affect which crops can most profitably be grown in BC and where. Crop suitability modelling uses our understanding of growing season requirements, phenological development, and/or critical temperature thresholds for individual crops to determine their suitability across the landscape. Model output using historical and future climate data can help the agricultural sector anticipate the effects of climate change on crop suitability, manage risks and adapt. There are a number of approaches to crop suitability modelling. Agriculture and Agri-Food Canada’s Land Suitability Ratings (LSRS) is used to predict the suitability of commercial field crops across the landscape; recent work using LSRS under a range of future climate scenarios suggests that crop suitability for corn may initially improve in the Fraser Valley up to the mid-century but that increasing temperatures will reverse this trend beyond 2050. Similarly, crop suitability modelling for sweet cherry, driven by modules for dormancy, spring phenology and growing season heat requirements, has shown that recent warming has extended the suitable growing region for sweet cherries northward and upslope; climate projections suggest that the Cariboo region may become available for cherry cultivation by the mid-century. In order to support BC’s agricultural sector into the future, expansion of transportation corridors and irrigation infrastructure will likely be required, as will a comprehensive assessment of the available irrigation water supply.
Recommandé
Recommandé
Contenu connexe
Dernier
Dernier (20)
En vedette
En vedette (20)
Changing Climate, Shifting Crops - Kirsten Hannam AAFC
- 1. Changing climate, shifting crops How might climate change affect the crops we grow in the Okanagan Valley? Denise Neilsen, Scott Smith, Grace Frank, Istvan Losso (AAFC, retired); Alex Cannon; Ron Fretwell; Molina Ith-Tek
- 2. Our climate is changing… 0 5 10 15 1916 1936 1956 1976 1996 2016 Annual number of days over 35°C 0 5 10 15 20 25 1916 1936 1956 1976 1996 2016 Annual number of days less than -20°C Environment Canada data for Summerland, BC https://www.cbc.ca/news/technology/greenhouse-gases- 1.5371968
- 3. Climate determines the types of crops we can grow… Cartoonstock.com Cartoonstock.com Cartoonstock.com
- 4. We can use modelling to help us anticipate changes in crop suitability across the landscape…
- 5. 1. Suitable sites Slope <30% Soil depth > 50 cm Well-drained < 60 % stones Low salinity Neilsen et al. 2017. Modelling changing suitability for tree fruits in complex terrain. Acta Hortic. 1160:207–214
- 6. 1. Suitable sites Slope <30% Soil depth > 50 cm Well-drained < 60 % stones Low salinity
- 7. 2. Weather data - daily (500 m resolution) Minimum temperature, December 29th, 1968 Maximum temperature, July 30th, 2003 Neilsen et al. 2017. Modelling changing suitability for tree fruits in complex terrain. Acta Hortic. 1160:207–214
- 8. 2. Weather data - Agro-climatic indices Growing season length (frost-free period) 0 2800 1200 800 400 2400 2000 1600 Growing degree days Neilsen et al. 2017. Modelling changing suitability for tree fruits in complex terrain. Acta Hortic. 1160:207–214
- 9. 3. Crop suitability models SPRING: Do temperatures get cold enough to damage flower buds? GROWING SEASON: Are there enough warm days for the fruit to reach maturity? Does get hot enough to damage fruit? AUTUMN & WINTER: Do temperatures get cool enough to allow trees to complete dormancy requirements? Do temperatures get cold enough to damage flower buds? Do temperatures ever drop below -30 C? Neilsen et al. 2017. Modelling changing suitability for tree fruits in complex terrain. Acta Hortic. 1160:207–214
- 10. Changing distribution of sweet cherry suitability Climate AND soil/landscape suitable Climate suitable but soil/landscape unsuitable Unsuitable Neilsen et al. 2017. Modelling changing suitability for tree fruits in complex terrain. Acta Hortic. 1160:207–214
- 11. But what about crop suitability into the future? Canadian Earth System Model 2 (CanESM2) ‘Representative concentration pathway’ (RCP) 8.5 (radiative forcing of 8.5 W m-2) Used to model past and project future daily temperatures for the Okanagan Valley 50 ‘realisations’ driven by CanESM2 Each ‘realisation’ begins in 1950, using a randomly generated ‘seed’, and is run until 2100 Daily climate data generated at 500 m2 spatial resolution
- 12. Sweet cherry suitability – 1950s Suitable 21-30 times out of 50… Suitable 0-10 times out of 50… Suitable 11-20 times out of 50…
- 13. Suitable 41-50 times out of 50… Suitable 31-40 times out of 50… Sweet cherry suitability – 2000s
- 14. Sweet cherry suitability – 2050s
- 15. Will fruit be damaged by heat? Do temperatures drop below -30 C? Will flower buds be frozen in the fall/winter? Is the growing season long enough for fruit to mature? Will flowers be frozen in the spring? Are dormancy requirements met? What is driving the shift in sweet cherry suitability?
- 16. Will fruit be damaged by heat? Do temperatures drop below -30 C? Will flower buds be frozen in the fall/winter? Is the growing season long enough for fruit to mature? Will flowers be frozen in the spring? Are dormancy requirements met? What is driving the shift in sweet cherry suitability?
- 17. So… is climate change is good for agriculture in the Okanagan Valley?
- 18. Insects and pests… Pest/Disease Hosts Suspected Year of Introduction into BC Apple clearwing moth (Synanthedon myopaeformis) All tree fruits, mountain ash, hawthorn 2000 Spotted wing drosophila (Drosophila suzukii) Tree fruits and berries 2009 https://www.bctfpg.ca/ifp-organics/invasive-alien-pests/
- 19. 2015 2016 2017 2018 2019 Flood Wildfire Drought Extreme events… www.bclocalnews.com/news/ www.ctvnews.ca/canada
- 20. 0 50 100 150 200 250 300 350 Bonaparte Cariboo Comox Cowichan FraserValley Kettle Kootenays Lillooet Nicola N.Okanagan N.Thompson Okanagan Pemberton SalmonRiver Similkameen S.Thompson S.GulfIslands MLx1000 Historic 1960-2000 Increase due to land use change Increase due to climate change Neilsen et al. 2018. Frontiers Environ Sci. Landscape based agricultural water demand modeling – a tool for water management decision making in BC, Canada. 1160:207–214 Irrigation water needs… Indicators of climate change for BC. 2016 update. https://www2.gov.bc.ca/gov/content/environ ment/climate-change/adaptation/impacts
- 21. Changing climate, shifting crops… Climate is changing in the Okanagan Crop suitability is shifting (sweet cherries) Modelling suggests that crop suitability will change dramatically in the next few decades Cold temperatures expected become less limiting to fruit production Fruit production may become limited by other factors (e.g., heat; pests and disease; smoke; availability of irrigation water) What can we do to prepare? How can we adapt? Denise Neilsen, Scott Smith, Grace Frank, Istvan Losso (AAFC, retired); Alex Cannon; Ron Fretwell; Molina Ith-Tek
- 22. Suitable 41-50 times out of 50… Suitable 31-40 times out of 50… Sweet cherry suitability – 2000s
- 23. 3. Crop suitability models Risk SPRING: Do temperatures get cold enough to damage flower buds? >2/10 yr to >5/10 yr GROWING SEASON: Are there enough warm days for the fruit to reach maturity? >3/10 yr Does get hot enough to damage fruit? >5/10 yr AUTUMN & WINTER: Do temperatures get cool enough to allow trees to complete dormancy requirements? >3/10 yr Do temperatures get cold enough to damage flower buds? >4/10 yr Do temperatures ever drop below -30 C? >0/10 yr Neilsen et al. 2017. Modelling changing suitability for tree fruits in complex terrain. Acta Hortic. 1160:207–214
Notes de l'éditeur
- The Okanagan Valley is undergoing major land use changes. A lot of these changes are driven by massive population growth, which is putting increasing pressure on available agricultural land, and water. As well, longer growing seasons, more extreme heat events in the summers, and increasing land prices have been driving producers to plant crops farther north and at higher elevations (this is particularly true for cherries, a high-value export crop that is shipped mainly to the Asian market).
- Work completed by Environment Canada (Alex Cannon), using Anusplin data from NRCan, upsampling according to ClimateBC algorithm, and bias-correction as per PCICs Prism climatology.
- Below -30 C for > 1 day; > 37C for > 3 days Year round plant growth and development models Tested against threshold damaging temperatures at all stages Empirical models developed from regional survey data and controlled laboratory studies
- Climate and land use change alter what we can grow and where Modelling can be used to predict where crops grow best Models using historical data are consistent with observations of shifting sweet cherry cultivation upslope and farther north Models using climate projections suggest crop suitability will become less limited by cold Average output from 20 global climate models under 4.5 and 8.5 rcp Soil and landscape suitability, using high resolution maps (1:20,000): Slope <30%, depth to bedrock >50 cm, not poorly drained, coarse frag < 60%, not saline Climate modelling, using high spatial and temporal resolution gridded dataset Phenology/hardiness modelling, i.e., daily temperature thresholds by phenological stage, e.g., winter dormancy, spring floral development, summer fruit growth, cold hardiness Combined risk assessments by year, and mapped in GIS
- - currently available 500m gridded daily Tmin, Tmax, Precip datasets and five models from the CMIP5 ensemble (RCP 4.5, 8.5) downscaled to the same spatial and temporal scales. All datasets available for the whole of BC.
- Recently introduced pests relevant to orchard trees in OKV
- Below -30 C for > 1 day; > 37C for > 3 days Year round plant growth and development models Tested against threshold damaging temperatures at all stages Empirical models developed from regional survey data and controlled laboratory studies