Tree rings are densely oriented toward the shade, that is, the north. Because an annual ring is the growth of a big tree in a year, and whether a big tree grows vigorously depends on the lighting conditions. For big trees, the light conditions facing south are definitely better than those facing north, so big trees facing south grow stronger than those facing north, and the annual rings facing south are wider than those facing north.
Tree ring analysis:
1. Look at the direction: the annual rings are wide and narrow, and the wide and thin side of the annual rings indicates that the tree is growing well, facing the sunny side, that is, the south. The narrow and dense side of annual rings shows that the growth potential of big trees is poor, and they are facing the shady side, that is, the north.
2. Look at age: one annual ring is the growth of big trees in one year. We can judge how many years this big tree has lived by observing the number of rings. But if the temperature drops sharply in a certain year and then rises again, there are likely to be two rings in that year.