The olive is a diva who wants to stay young, she moves non-stop towards the future full of youth, everything old leaves it behind, it dries it, even its trunk!
But we humans, who pass by her like butterflies, want to date her ... What strange creatures!
When we say dating we mean the determination of the age of the olive trees.
The classic method based on the number of annual rings presents many difficulties of application because the olive trees do not retain the wood of their central trunk completely, especially the very ancient ones.
The trunk consists of four main parts, the bark, the cambium, the wood and the intestine.
The cambium is located between the bark and the wood and is a very thin layer of meristematic cells that are cells that reproduce creating new cells that form the inside of the bark outwards and the wood inwards.
The wood contains the conduits through which water is transported mainly from the root to the aboveground part of the tree but also another group of conduits called the filter through which mainly organic substances are transferred from the mature leaves to the rest of the tree.
The cambium extends along the entire length of the tree trunk axis and remains active throughout the life of the tree.
Each year the cambium forms the annual ring of several cells thick depending on the time of year and the prevailing conditions, thicker and lighter in early spring and narrower and darker towards winter as the activity of the trees decreases. Thus, the thickness of the trunks is created.
The olive tree, although it does not "get fat" at a high rate, in its centuries-old course of thousands of years, has enough trunks with a perimeter of more than ten meters. However, the inner part of the wood, through some normal functions, dies and is rejected, with the consequence that the dating through the annual rings does not have the exact application as in some other species of trees.
Our olive tree hides its age!
However, a rough approximation of age να can be made βάση based on the perimeter and the calculation of the radius, having as a given the average annual length of radial growth of the olive tree.
This length varies depending on the variety, but also the soil-climatic and nutritional conditions that existed in the area of the tree during its life, it is estimated that it usually ranges between 0.8-1.5 mm / year. Therefore we need mathematical formulas for our calculations, perimeter Π = 2πr where r is the radius of the trunk we measured or r = Π / 2 * 3,14 and after calculating the radius r we will divide it by the radial growth rate ΜΑ = 0,8 -1.5mm and we will calculate the age H = r / MA.
Another more accurate way of dating that takes advantage of the technological advancement of science is dating with the radioactive carbon isotope 14, 14C.
An isotope is the atom of an element that has the same number of protons and a different number of neutrons in its nucleus, carbon has three major isotopes 12C, 13C and 14C.
Radioactive 14C is produced by cosmic rays in the upper atmosphere, that is, by high-energy incident particles from distant stellar explosions in space.
14C is taken up by photosynthesis in the form of CO2 from plants,
but when the tree ceases to live the 14C is not renewed and its content tends to zero as it decomposes over time to 5730! years half of the 14C atoms will have remained from the original concentration while the rest will have been transmuted (the 14C half-life is 5730 years).
Comparing the initial concentration with the current one, we calculate the age of the olive tree.
We will return to this as soon as we have the results from Democritus ...