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CLIMATE CHANGE

Stefanos Koundouras PhD explains how urgent is the need to address the issue of global warming in order to prevent and/or reduce some the negative effects that would potentially have on viticulture.

CLIMATE CHANGE AND VITICULTURE

The new challenge

Climatic change is possibly one of the most discussed and researched issues of our time.  The rise in temperature at an international level over the last decades has serious effects in the agricultural production and by extension in viniculture.  The physiology of the vine is very sensitive to any climatic change and this is reflected in how it reacts in fluctuations of the weather producing different results every year.  The quality of production and the genuineness of the wines is reliant on a system of interactions between the climate, the terroir and the produced variety within a defined geographical area with the climate possibly being the main factor influencing the wider potential of an area as to the prosperity of each vine variety and the production of a certain type of wine.  Furthermore, it decisively influences the quality of the grapes and by extension the quality and the character of the wines produced by them.

 

Within this framework, the rising temperature causes disruption in the sprouting cycle of the vine leading to an early growing cycle and abridgment of all its phenological stages.  This means that a relatively warm winter will cause early budding, a warm May will cause early flowering and a warm summer early veraison and by extension early harvest.  Thus, the maturation of the grapes is passed on to the warmest period of the year, which jeopardizes the natural maturation of the grape.

 

The quality of the organoleptic characteristics of the grape and more specifically the variety (aromas, phenolic reactions), and not necessarily the sugars and acids, is favored by mild temperatures either during the day or night.  “It is not by luck that almost all the varieties traditionally mature in September, the month in the year with the mildest temperatures.  It is not advisable, for example, that the harvest of the Sauvignon Blanc in Greece take place in August and this is because the quality and the aromas will not be equivalent to those of the wines in Loire where the harvest takes place in October” Stefanos Koundouras points out and goes on “However, the adverse result related to climatic change is quite more complex as it is not connected only to the climatic boundaries of the area where the variety is cultivated (the differentiations from area to area are relatively small) but mainly to the combination of the variety with the area where it is cultivated, the natural environment in which it is growing.  A variety which matures slowly in an area, for example, Moschofilero in Mantinia or Xinomavro in Aminteo and up to a point in Naoussa, does not seem to have a problem.  On the contrary, in the long term and where applicable, it could even have positive results.  So, while we used to have one “great” Xinomavro on an average for two consecutive years, now we could have five.  A variety that would mature borderline, now it can mature more easily.  On the other hand, a variety that matures early lacks a great deal of the aromas, the typicality, the finesse or its varietal character.

 

Therefore, the areas, with mid-early and early varieties are those which will suffer more while in areas with late varieties the results will be less significant or even positive.  A good example is the wines from the area of Bordeaux.  The chances of great wines being produced are significantly increased.  Lately, however, the character of the wines of this area tends to resemble that of the New World and the wines lose the so-called “typicité”.  Thus, even though we get mature wines, what seems to alter is their terroir and especially of those with a protected origin appellation.  When the area ceases to be suitable for a given variety or varieties any more, the whole ecosystem is essentially redefined, the terroir (suitable soil, suitable climate, the variety/varieties that mature ideally).”

 

Although we are referring, in general, to a global phenomenon, the effects to each area are specific and always in correlation with the variety and the type of wine being produced.  A parallel impact of the rise in temperature is the rise in evapotranspiration and by extension in the development of the vine through photosynthesis.  When the vigor is increased, adverse conditions for the maturity of the production are created.  Moreover, the vine is facing increased water stress, as the water reserves of the ground are depleted quickly, rendering a greater need for irrigation.

 

According to Stefanos Koundouras, concerning Greece, “climatic changes are not going to affect all areas similarly.  The southern areas and the islands will be affected more than the northern areas, the plains more than the mountainous-semi mountainous areas,  the mainland more than the coast and the poor and shallow soils more than the fertile ones.  Furthermore, the foreign early-maturing varieties, will suffer more compared to the late-maturing like the indigenous Greek ones.  Consequently, 90% of the Greek varieties are not in any immediate serious danger”

 

The answer to the question if Greece has taken any adaptation measures to face this phenomenon does not make us feel very optimistic.  Any initiative related to prevention, is mainly based on individual efforts rather than a common collective strategy.  The record and understanding of this phenomenon must begin, as usual, by an official body, with the aim of providing the proper directives for facing it, as does, for example, the OIV, the International Organization for Vine and Wine or the Producers’ Union in Australia.  For many years now the OIV has formed a committee which deals with the study of climatic change phenomena, while at the same time it works closely with producers on prevention by special suggestions/adaptation measures.

Unfortunately, the respective Greek suggestions have not managed so far to convince the majority of the wine producers about the need to take measures to face a problem whose chances of arising in the long term are very big.  Nevertheless, the developments and changes that are observed in the form and way that the Greek vineyard is managed contribute positively to the dealing of the phenomenon, although they are not the result of the intention to face the problem, and their coinciding with the official scientific adaptation proposals can be considered rather circumstantial.

 

For instance:

The change that has been noticed in the Greek varieties the majority of which are late-ripening and present better adaptation ability in arid and hot environments than most of the international varieties.

The use of subjects that are tolerant to drought and saline soils.

The planting of new vineyards in altitude or coastal areas where, respectively, the average daily temperature is lower and the average temperature range is smaller, thus allowing the smooth and gradual phenologic maturation of the grapes.

Changes in the cultivation practices, like irrigation by application of regulated water stress or the proper shoot pruning can help the vine develop correctly.

Even the change in the product, as long as the climatic change would render an area unsuitable for the production of a certain type of wine, could be another alternative way to resolve the problem.  However, selecting this extreme and especially brave “solution” is considered quite difficult for areas producing PDO (Protected Designation of Origin) wines , where the geographical boundaries and the variety or varieties are strictly defined by legislation, as well as for producers who hesitate to take such a radical step.  A move that, on the one hand, would have high cost but, on the other hand, would secure, in the long term, the viability of the producer’s business.

Some of the various and different scenarios that have to do with the evolution of he phenomenon are pessimistic and others relative optimistic.  More rather than few are those who are quite skeptical about the climatic change phenomenon rejecting definitively the possibility of its existence.  It is true that no research can prove the accuracy of the theory that it stands for as it is based on indications and not on unshakable scientific evidence which can constitute an objective truth.  Nevertheless, the greater danger is always hidden there where we cannot predict it and that is exactly where prevention can be proven to be beneficial.

 

As far as the possibility of raising the issue of the viability of the Greek vineyard, fortunately, at least for the moment, there is no such issue according to Stefanos Koundouras.  Unfortunately, however, no research model is in a position to confirm this, setting as immediate priority the taking of preventive measures to face the phenomenon, starting from the creation of a database (meteorological, phenological, analytical and organoleptic data) for each Greek viniculture zone.  This would lead to the better understanding of the true dimension of the phenomenon, as it is a requirement for the proper design of a strategy that could promptly reduce the negative effects that it would potentially have on viniculture.

 

 

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