Some problems about plants

I have answered a lot of the first three questions upstairs, so I won't bother you. I will answer the last three questions by copying others' unkindness.

4. Color-leafed trees are simply trees with specific leaf colors, including trees, shrubs and vines.

Panchromatic leaf tree: From appearance to withering, almost all leaves are colored. Common gymnosperms, such as golden sequoia, golden cypress and blue spruce; Michelia flava, Ligustrum lucidum and Berberis purpurea in angiosperms.

Seasonal colored-leaf trees: Leaves are colored in one or two seasons. Such as spring, summer, autumn or winter. Such as mountain hemp pole, torch paint, maple incense, etc. Generally, plants with autumn leaves are more valued.

Autumn foliage trees: trees with colorful leaves in autumn, such as Ginkgo biloba, Maple, Maple, Cotinus coggygria, Fraxinus mandshurica, Sapium sebiferum, rosewood, Taxodium ascendens and Sassafras sassafras.

5. According to the light, plants can be divided into short-day plants, long-day plants, Chinese and Japanese plants and intermediate plants. The finer plants are long-day plants and short-day plants, and the latter two will be mentioned in very professional fields.

According to the relationship between plants and water, plants can be divided into xerophytes, mesophytes, hygrophytes and aquatic plants.

In addition, terrestrial plants can be divided into two types according to the range of their own water content: variable water plants and stationary water plants.

I don't know where to answer this question. Generally speaking, plants have the greatest demand for water during seed germination and seedling stage. The principle is that the more vigorous the life activities of plants, the faster the metabolic frequency, and the greater the demand for water. In addition, more than 98% of the water absorbed by plants from soil is consumed in transpiration, which is mainly used for transportation and does not enter the metabolic cycle of plants.

Different plant species and varieties have different needs for water, and the same plant has different needs for water at different growth and development stages. Generally speaking, there is less water demand in the early and late growth stages and more water demand in the middle growth stage. Plants are sensitive to water at different stages of growth and development. The most sensitive period to water is called the critical period of crop water.