Bird trees are good, birds make nests, big trunks and so on.

A bird tree is good, and birds nest in it. When the wind comes, trees spread their branches and leaves to protect the birds' homes.

Trees are perennial plants with wooden trunks and branches. General tree Screaming Trees, the main plant is one, the branches are higher from the ground, which can form a crown. Canopy has the function of rain protection, which can reduce the impact of rain on the surface and maintain soil and water. Canopy can block 10%-20% of rainwater, most of which will evaporate into the atmosphere, and the rest will fall to the surface or enter the soil along the trunk of trees, forming a reservoir.

The tree kingdom can improve the quality of the environment on which human beings depend. The tree kingdom and green plants continue to carry out photosynthesis, consuming carbon dioxide and producing fresh oxygen. The tree kingdom can also play an important role in protecting the environment on which human beings depend. We know that strong wind will increase soil evaporation, reduce soil moisture and cause soil wind erosion.

Tree rings

Tree rings are a layer produced by the growth of trees in a year. It appears in cross section like a wheel (or wheels) around the same wheel produced in the past. The scale ring in fish refers to the dividing line between the narrow band formed in autumn and winter and the wide band formed in spring and summer the following year. The secondary xylem produced by vascular cambium of annual rings in a growing period constitutes a growth ring. There is obvious seasonality, and only one growth ring is produced in a year, that is, the age of trees, also known as tree rings.

Under favorable climatic conditions, trees grow well, xylem increases a lot, and annual rings are wider; On the contrary, the annual rings are narrow. For example, the initial rings of trees are generally wide, indicating that the trees at that time were young and strong; Sometimes a tree suddenly appears wide rings after many narrow rings appear, which shows that the environment and climate are suitable for the growth of the tree in those years when the rings are wide.