Climats Flashcards
What are the 5 most important things a vine needs to survive?
Heat
Water
Sunlight
Nutrients
Carbon dioxide
Finish this equation:
Sunlight + CO2 + Water = ____ and ____
Glucose and Oxygen
Vines use ___ and ___ to fuel its growth and ripen its grapes.
Glucose and nutrients from the soil
Oxygen is one of the byproducts of photosynthesis, but vines don’t use oxygen.
What does the vine do with the oxygen it creates during photosynthesis?
The vines release it through their leaves.
What is the defining factor that determines which grape varieties can grow where?
The amount of heat an area gets during its growing season.
Something to keep in mind: continentality + a region’s proximity to bodies of water are tied into this because they help influence the region’s total amount of heat during the growing season.
What 7 natural factors affect/influence temperature and heat in a vineyard?
Latitude
Altitude
Ocean Currents
Fog
Soil structure
Slopes and aspect
Diurnal range
What 3 factors affect/influence sunlight in a vineyard?
Latitude
Bodies of water
Aspect
What are the optimal latitudes for growing vines around the world?
Between the 30th and 50th latitudes north and south of the Equator.
Put another way, between latitudes 30 and 50 degrees in the northern and southern hemispheres.
Why isn’t it possible to cultivate grape vines close to the Equator?
Because areas close to the Equator have annual average temperatures that are far too high which do not allow the vine to go dormant. And if a vine is unable to go dormant, it’ll produce less-than-optimal fruit and tire out in only 15-20 years.
Fun Fact: there is one place in Northern Brazil, Vale de São Francisco, that is capable of two harvests per year.
How does altitude affect temperature?
As altitude increases, temperature decreases.
Altitude is what allows some regions to exist closer to the Equator, e.g. Cafayate, Argentina which sits ~3,000m above sea level.
What is the effect of the Gulf Stream on Europe?
The Gulf Stream adds a warming effect to the climates of northern and western Europe.
The Gulf Stream originates near the tip of Florida and crosses the Atlantic Ocean.
What is the cold ocean current that affects South Africa?
Benguela Current
Name the cold ocean current that affects Chile.
Humboldt Current
How can fog be beneficial to vineyards?
It can have a cooling effect on vineyards which would otherwise have difficulty growing premium grapes (the vineyards would get hot and stay hot).
How can rocky/slatey/stony soils affect a vineyard’s temperature?
Rocky, slatey soils - stony or dark in color - absorb heat during the day, and release it overnight.
Examples include:
Galets roulés in Châteauneuf-du-Pape Blue slate in the Mosel Llicorella soil in Priorat
Which way do vineyards face in each hemisphere to ensure optimal sun exposure?
Vineyards in both hemispheres will face the Equator for optimal sun exposure.
Northern hemisphere vineyards will face south.
Southern hemisphere vineyards will face north.
What is a diurnal shift?
A diurnal shift is the change in temperature from daytime to nighttime.
The larger the diurnal shift (lower lows, higher highs) the better it is for the vine; warm daytime temps help develop sugar and phenolic ripeness whereas cool nighttime temps help preserve acidity and freshness.
What are two things that can reduce diurnal range?
A vineyard’s proximity to a body of water
Cloud cover
Besides decreasing diurnal range, how else does cloud cover affect a vineyard/vines?
SLOW FLOWERINF AND FRUIT SET because the vine is not getting enough sunlight to photosynthetize, which ultimately produces a smaller crop;
Heavy clouds can STOP GRAPES FROM FULLY RIPENING.
What does continentality mean?
It is the difference between the coldest month and the hottest month in a region.
Regions with high continentality have big differences.
What effects do bodies of water (oceans, lakes, rivers) have on climate?
Bodies of water HELP MODERATE TEMPERATURES, REDUCING CONTINENTALITY ie temperatures will be neither extreme lows nor severe highs.
Vineyards in close proximity to bodies of water have diminished diurnal range as large bodies of water emit stored warmth at night (and during the beginning of winter) and supply cool daytime breezes.
Describe lake effect.
As large bodies of water take a long time to warm up and coll down, LAKE EFFECT HAS A MODERATING EFFECT ON CLIMATE.
In autumn, a lake that has warmed up during the summer releases its accumulated warmth to the surrounding land thereby extending the growing season for grapes and keeping away early frosts.
During spring and early summer, the lake is still cold from the winter. As the land around the lake heats up, warm air rises from the earth which sucks in the cool air coming from the lake, creating on-shore breezes.
At what temperature can vines be damaged or killed by a deep winter freeze?
-20
The part of the vine that’s most susceptible to winter freezes is the ___.
GRAFT (if the vine has been grafted)
What does ‘earthing up’ mean?
When a viticulturist mounds up additional soil around the base of the vine’s trunk as an insulation layer to help retain warmth over winter.
This is done to young vines to protect them against deep winter freezes, especially new grafts.
Describe what spring frost is.
What kind of damage can it do?
When cold air below 0° freezes water vapor hovering at ground level or around the vine. Frost can kill new shoots and buds that have just burst, impacting yields.
What are the 4 important protections a viticulturist can take against frost?
HEATERS and smudge pots which create a blanket of warmth to keep the vineyard from freezing;
FANS, WIND MACHINES OR HELICOPTERS to circulate warm air aboce the ground with the the cold air that settled around the vines;
SPRINKLERS, which spray water onto a vineyard so that a thin layer of ice forms on the vine to insulate it.
CONSCIENTIOUS VINEYARD DESIGN to avoid depressions; can also high-train vines.
Why do rivers mitigate frost damage?
Rivers keep air moving (instead of settling) in vineyards.
Name 2 ways cold springtime temperatures can affect vine/plant growth.
DELAYED BUDBURSTING => shortens growing season
DISRUPTED FLOWERING / FRUIT SET => lower yield
What can sustained, extremely high summertime temperatures lead to?
SLOW OR STALLED VINE ACTIVITY ; vine can shut down
DEATH of the vine.
What 2 climate features are most influential on grapevines?
RAINFALL
TEMPERATURE
What is the difference between climate and weather?
Climate is a region’s expected, annuel average of temperature, sunlight, warmth and rainfall over time;
WEATHER is what happens day-to-day.
What are the months defined as the “growing season” in the Northern and Southern Hemispheres?
N: April - Oct
S: Oct - April
Define cool climate.
Average growing season temperature of 16.5 and below
Define moderate climate.
Average growing season temperature of 16.5 to 18.5
Define warm climate.
Average growing season temperature of 18.5 to 21
Define hot climate.
Average growing season temperature of 21 and above
Describe Maritime climate.
LOW CONTINENTALITY areas influenced by large bodies of water, having WARM SUMMERS AND MILD WINTERS with RAINFALL YEAR-ROUND.
Bordeaux, Rias Baixas
Describe Mediterranean climate.
Low continental areas that have WARMAND DRY SUMMERS, and COOL, RAINY WINTERS.
They tend to produce riper, fuller wines.
Southern Rhone, McLaren Vale
Describe Continental climate.
HIGH CONTINENTALITY with climate extremes: WARM AND/OR DRY SUMMERS WITH COLD WINTERS.
They tend to be inetrior regions.
Champagne, Ribera del DUero
What encourages Noble Rot (Botrytis)?
When early morning mist or fog from nearby bodies of water create humid land conditions which are the followed by warm, dry and sunny afternoons.
The humidity allows Bitrytis spores to attack the grapes; the sun-filled afternoons allows the spores to germinate.
Sauternes and Tokaj
What is the rain shadow effect?
As weather systems move from west to east, foul wetaher is stopped by or trapped in mountains thereby leaving the eastern side of mountains with brilliant sunshine and nice weather. The western side gets all the rain and clouds.
Voseges, Cascades ans Andes mountains.
Because rain shadows provide warm, sunny weather for the leeward side of mountains, what does that allow vignerons in rain shadows to do?
Vignerons can plant vineyards at higher altitudes on the leeward side to help the vibes find cool nights, down drafts and drainage.
Salat (Argentina) is planted at high altitude on the eastern side of mountain ranges.
What happens to a vine when it suffers from drought conditions?
A vine will shut down if it does not have anough water to produce photosynthesis:
- leaves stop working
- sugars are not produced
- grapes don’t ripen properly.
What is the difference between altitude and aspect?
Altitude is height below sea level, eg Mendoza is 900-1500m above sea level.
Aspect indicates the direction which a slope faces, eg top sites in Burgundy have a southeasterly aspect which provides them more gentle morning sun and protects them from hot afternoon sun.
Why is rain at harvest not a good thing?
Rain in harvest can result in:
- dilution of flavors in grapes
- dilution of sugers
- create rot.
What is the damage that hail can do to a vineyard?
Hail can:
- PERFORATE LEAVES so that photosynthesis is not possible anymore
- DAMAGE BUD WOOD, creating open wounds which invite bacteria
- KNOCK CLUSTERS OT GRAPES OFF THE VINE, decreasing yields.
