Listen to the “sound” of annual rings

They are different in size and look “mature and stable”; they have experienced the precipitation of time, recording their life track in the unique way of “circle” in nature…The four seasons change, they experience this ever-changing world firsthand, recount The story of growth. They are the witnesses and recorders of nature-tree rings.

Natural Imprint Growth File
The annual rings we observe are the concentric circular patterns seen on the tree stumps, like a playground runway, and a runway represents an annual ring. When the tree growing season begins, a large number of large, thin-walled cells are formed between the old xylem and phloem, the cambium. With the end of the growing season, the individual cells gradually become smaller and the cell wall thickens until the cambium cells stop producing and complete a growth cycle. The cells of the cambium grow outward to form new bark, and grow inward to become new wood. The reason for the horizontal development is to extend vertically. Most of the growth of trees will be recorded in the form of life by the cambium, and finally reflected in the annual rings.

The mystery is infinite
Count the growth rings of a tree to know how old it is. Usually a circle of annual rings represents one year old, and a circle of annual rings also represents a cycle of the growth environment that the tree experiences during the year. Of course, not all trees have a circle in a year, and annual rings that do not conform to this law are called “false annual rings”. The production of “false annual ring” is mainly caused by the disorder of the growth of cambium cells, which is attributed to the characteristics of the plant itself, and is also affected by the external environment. The former, such as a citrus plant, can produce 3 annual rings in a year; the latter, such as abnormal climate or insect pests, with multiple cold and warm or leaf fall out, causing significant fluctuations in cambium activities, resulting in multiple growth changes, forming Multiple concentric ring layers.

Two concentric ring layers

Through observation, we can find that some circles in the annual rings are squeezed together, and some circles are farther apart, and the density is different. This is mainly due to the influence of the type, age and living environment of the tree. For example, the annual rings of poplar and Maotong are wide, and the annual rings of boxwood and dogwood are very narrow. This is determined by the congenital conditions of the tree species. The wide annual rings formed by the tree at the beginning of its growth indicate that it was young, strong and vital. But as the tree ages, the annual rings gradually narrow, just as the collagen on the human face gradually loses with age. The living environment is good, such as sufficient sunshine and rain, suitable temperature, and rapid growth of cells, the annual rings will appear sparse, and vice versa.

The looser growth rings The tighter growth rings The difference between early wood and late wood

The shade of the annual ring color is also closely related to the season, environment and other factors. In spring and summer, the climate is warm, the nutrients are sufficient, the cambium cells are active, the differentiated vessel molecules are many, the diameter is large, the wood texture is loose, and the color is lighter, which is called “early wood” or “spring wood”. In autumn and winter, the temperature drops and the nutrients decrease. At this time, the activity of cambium cells gradually weakens or even in a dormant state. The differentiated vessel molecules are correspondingly reduced, and the diameter is small, the tube wall is thick, the wood fiber is more, the wood texture is tight, and the color is usually relatively ” “Earwood” is darker in color and is called “latewood”. The shades of different seasons in the same year combine to form a ring, which is the annual ring of alternating shades we see.

Different annual rings show individuality
Time and trees are added together to form annual rings, each of which is a unique note of the tree, and the combination is the sound of nature. Every tree has its own growth trajectory. Different tree species, different ages, and different growth environments will produce tree rings with different characteristics, so the annual rings show the individuality of the tree. Can we read growth information from them?

The osmanthus tree was visually inspected for a few times, and the osmanthus tree was about 25 years old. Accurate annual ring data can also be obtained with professional tools such as “growth cones” and sandpaper, without cutting trees.

With the continuous growth of cambium cells, the metasequoia tree will gradually lose its ability to transport water to the center, and the material will gradually become harder, that is, the darker part of the trunk, such as the annual ring color of this metasequoia tree. The dividing line is clearly visible.

Each tree ring records information such as sunlight, sunlight, rainfall, and soil. Through the study of tree rings, it has important guiding significance for estimating the age of trees, investigating the age of forests, understanding the meteorological conditions of the year, recording climate changes, reflecting environmental issues, and formulating afforestation plans. At the beginning of the 20th century, American astronomer Dr. Douglas started with a few tree stumps and forged an indissoluble bond with tree rings, thus creating a new scientific field-dendrochronology, through the study of large trees. The annual ring has come to scientifically determine the age.

Days of idle clouds are lingering, and things change for a few autumn. Annual rings tell the roots of the spring and fall, leaving the mark of the years, and at the same time, it also leaves precious wealth to people.