The article tells about what an annual ring is, how it is formed, where it can be found, what kind of science studies rings.
Trees and life
Life on our planet was formed and exists due to many factors, and one of them is the appropriate gas composition of the atmosphere. More precisely, the presence of a sufficient amount of oxygen. They provide us with plants that absorb carbon dioxide exhaled by most living things. Currently, most developed and civilized countries strictly monitor the condition of their forests, including the creation of national parks where you can find very old trees. They are interesting not only from an aesthetic point of view, but also because scientists, by studying them, gain knowledge about bygone times, and the age of trees is determined using tree rings. But what is an annual ring, why is it formed, and where, besides trees, is there more? This is what we will understand in this article.
Definition
Annual rings, or annual layers, are called areas of cyclic growth of tissues in plants and some other types of living beings, for example, mushroomsand shellfish. Their appearance is due to climatic temperature differences and some other factors. Now we know what a growth ring is.
But the most characteristic and pronounced growth rings are observed in woody plants of perennial type. Especially those that grow in the zone of temperate latitude, when periods of summer-spring growth of the cambium alternate with a dormant period in the autumn-winter part of the year. If we talk about the appearance of the rings, then each of them is divided into two parts: dark and light. Coniferous trees are interesting in that their growth rings are most clearly visible, since the wood that was formed later has a pronounced dark tint. Now we know what an annual ring is. They are studied by such a science as dendrochronology.
Dendrochronology
Dendrochronology is a scientific discipline that deals with the dating of events, natural phenomena and archaeological finds based on studies of tree rings of wood or other biological remains that possess them.
For example, this method is most often used to determine the age of some objects or structures made of wood by tree rings.
We figured out what kind of science it is and what it does. Now let's look at how growth rings form.
Educational process
As we already know, they appear in those trees that grow in areas with brightpronounced seasonality. Simply put, in summer and winter they do not grow in the same way due to temperature changes and other conditions. This leads to the fact that the layer of wood growing in winter differs from the summer one in a mass of features: color, density, texture, etc. If we talk about the visual manifestation, then on the cross cut of the tree trunk, you can see a clear structure in the form of concentric rings.
What can you tell from tree rings?
Basically it's age. Each ring corresponds to one year, according to its thickness and texture, one can judge what year it was then from a climatic point of view: approximate temperature, amount of precipitation, their frequency, and so on. This method is also used to determine the age of some ancient wooden products: they are sawn, they look at the number of rings, and then they are compared with a sample whose age is known. Thus, you can find out when the tree that served as the material for the item was cut down.
Animal world
As already mentioned, growth rings are found not only in trees, but also in the animal world. You can find them in those tissues or structures of the skeleton that grow continuously, but are subject to climatic influences, seasonal temperature changes. These are scales, bones and fins of some types of fish, shells of various types of molluscs, beaks and bones of birds, horns of animals, bones of some mammals. So now we know what tree rings are in biology. According to them, scientists determine everything the same as inin the case of trees: age, climate features of that period, and so on.
