Growth rings are the manifestations of adaptation of organisms to climate change, photoperiod, temp

The most straightforward I think is the nutritional change. Think of it, growth rings are a reflection of how well a plant grows each year. To grow directly depends on the nutrients it absorbs.

Like the climate, the temperature. Although light directly affects plant growth, it ultimately affects the synthesis and absorption of nutrients by plants. So, the individual thinks that the nutrition changes.

The biggest impact is climate change! Is it possible that the climate will change slightly and the lighting will change significantly? And temperature is only one part of the climate.

A growth ring usually consists of a growing season (spring and autumn).

a.Spring and autumn wood.

b.Sapwood and heartwood.

c.Spring and early wood.

d.Autumn timber and heartwood.

e.Latewood.

Answer analysis: aSpring timber and hidden limbs judge autumn timber.

Expansion: Walking into the forest, piles of tree stumps are steadily scattered in the forest, and the surface of the stump is surrounded by a circle of things that have been changed by the stove, which is called annual rings.

The annual rings are the traces of the years.

When the tree is felled, there are many concentric rings visible on the stump, which are botanically called hunger rings. Growth rings are formed by the seasons during the growth of trees, and they produce one round a year.

Every spring, the climate is mild, the rainfall is abundant, the trees grow quickly, the cells formed are large in size, the number is large, the cell wall is thinner, the material is loose, the color is lighter, and the early wood is formed, also known as spring wood.

In autumn, the temperature is getting cooler, the rainfall is scarce, the trees grow slowly, the cells formed are small in size, the number is small, the cell wall is thicker, the material is tight, and the color is darker, forming latewood, also known as autumn wood.

The spring and autumn timber of the same year are collectively called growth rings. There is a clear boundary between the autumn timber of the first year and the spring timber of the second year, which becomes the growth ring line, indicating the turning point of the alternating growth of timber from year to year. Therefore, the number of rings at the base of the trunk also directly reflects the age of the tree.

Scientists study the growth rings of trees 3,500 years ago, which reveal global climate change.

Warm and wet - cold dry - warm and wet.

Falling sea levels.

Causes: Plant growth, fast growth in warm and humid environment, large plant cells, large interstitial spaces, loose and sparse wood; In cold-dry climates, plants grow slowly and have smaller cells, so the rings are dense.

As a result, the dense rings reflect a cold climate, low glacier melt, and a drop in sea level.

Between the bark and the wood, there is a layer of cells called the cambium. In winter, the weather is dry and the cambium cells are in a sleeping state; In spring and summer, the temperature is high, the moisture is sufficient, the cambium cells are active, and the differentiated duct molecules are many, the diameter is large, and the tubes are large.

The walls are thin, and the wood texture is loose, so it is called''Earlywood''or''Spring wood'';In autumn, the temperature gradually becomes colder, the activity of cambium cells gradually weakens, and the differentiated duct molecules are correspondingly reduced, and the diameter is small, and the wall of the tube is also thick, wood.

There are many fibers, and the wood texture is tight, so it is called''Latewood. ''or''Autumn timber''。The early and late timber in the same year are combined to form a circle, which is called the growth ring.