It is clearly spring, but the streets in Chongqing are piled with yellow leaves like autumn. Do you know why?

At this time of year, Grain Rain is also the most suitable time for transplanting rice seedlings and planting melons and beans. However, it is clearly spring, but what we see on the streets of Chongqing is the same as autumn. ?

It really rained lightly in Grain Rain season. It cleared up briefly at noon and rained continuously in the morning and afternoon. It is this kind of cooling weather that leaves can be seen everywhere on the streets of Chongqing, among which Li Yi is the most obvious. Why? Let's talk about this topic together this afternoon.

Li Jue, formerly known as Huanggeshu, is the city tree of Chongqing, because it is in Chongqing dialect? Horn? With what? Ge? The pronunciation is the same. What do Chongqing people think the name of the tree should be? Wood? Besides, like metal? Kim. Besides, there are fish? Fish? The rivers, lakes and seas next to it are all divided into three parts, so Chongqing people have always called Pueraria lobata? Li Wei? . At this time of year, Grain Rain is also the most suitable time for transplanting rice seedlings and planting melons and beans. However, it is clearly spring, but what we see on the streets of Chongqing is the same as autumn. ?

It really rained lightly in Grain Rain season. It cleared up briefly at noon and rained continuously in the morning and afternoon. It is this kind of cooling weather that leaves can be seen everywhere on the streets of Chongqing, among which Li Yi is the most obvious. Why? Let's talk about this topic together this afternoon.

As a city tree, Castanopsis fissa can be seen everywhere in the streets of Chongqing. Many places in Chongqing are named after Castanopsis fissa, such as Huangjueping, Huangjueya, Huangjuexia and Huangjuedi. This kind of tree is extremely tenacious, and many of them grow on stone ridges, cliffs and city walls, with tight roots. Who does it belong to? Air root? Plants can grow with only a few roots in the soil, while bare roots can directly absorb water from the air. ?

Castanopsis fargesii is a tall deciduous tree with thick trunk, strange tree shape, hanging roots and bare claws, winding and full of ancient state. Dense branches, large branches extending horizontally, and branchlets obliquely bent. Not only strong vitality, but also long life. Ancient trees of a hundred years or even hundreds of years are very common in Chongqing. They are like handfuls of huge umbrellas, sheltering people from the wind and rain.

As for Castanopsis fissa, why do leaves fall in spring? It used to be explained that if you plant it, you will lose your leaves. In fact, this statement has no scientific basis and belongs to a misinformation. Pueraria lobata is a holly tree species between deciduous and evergreen, and its leaves have a long life. Deciduous leaves, which should have fallen in late autumn and early winter, did not begin to fall until the second year's mid-spring and early summer, and as soon as they fell, they grew tender leaves, and even some trees sprouted at the same time. ?

On the other hand, a more scientific explanation is that the leaves of Ilex species such as Quercus macrophylla in spring prolong their leaf life, which has two main benefits. First of all, leaves can carry out photosynthesis for a longer time, providing more energy for the growth of plants in spring. Second, nutrients such as nitrogen and phosphorus in old leaves that have not fallen off in winter can be transported to new leaves in spring, which reduces the nutritional deficiency caused by fallen leaves and is conducive to the rapid development of new leaves in spring. ?

It is precisely because of this that in recent days, because of the rain and cooling in Chongqing, the deciduous speed of this holly has accelerated, and there have been piles of fallen leaves on the streets in this group of pictures. Moreover, this phenomenon is not unique to Chongqing. Many cities in the south have this problem, among which the most common tree species are Liriodendron and Ficus latifolia.