About grassland, I think we all have a kind of feelings. Whether we have been to grassland or not, we all yearn for this kind of grassland feelings of “the sky is blue, the wild is vast, the wind blows grass, the cattle and sheep are low”. I don’t know if you have noticed, apart from your feelings for the vast grassland, why don’t trees grow on the endless grassland?
In some areas of the grasslands of African countries, there are many luxuriant trees, and even patches of forests. As we all know, the grasslands of China are mostly boundless, with green grass at the head, white clouds and blue sky at the head, and green weeds at the eye. It seems that people’s vision is always connected to the horizon. Some people may think that if there are trees on the grassland, it may destroy the beauty of the grassland, and it will make people uncomfortable to lose the mutual contrast of grassland weeds and blue sky. If we look at it from a scientific point of view, why are there so few trees in China’s grasslands?
First of all, we should exclude man-made felling, because in individual grasslands of our country, almost all trees are planted by man, so that even if people cut down trees, they will not cut down some saplings. Moreover, with the development of science and technology, there are many alternative energy sources. No one will waste energy to cut firewood, so this reason can be ruled out. Since human causes are eliminated, we should start with natural causes. When it comes to natural reasons, we have to mention the specific environment in which trees grow. On the grassland, water, soil and suitable temperature are the most indispensable for the growth of trees.
Water is the source of life, and all things cannot grow without water. Water plays an extremely important role for both plants and organisms, but in the grassland area, it is dry all the year round, not only lack of precipitation, but also the surface water resources are very scarce. The growth of trees needs a lot of water. The precipitation of grassland in China is limited and the water storage capacity is not strong. The reason why African grassland has lush trees is that it has strong water storage capacity.
Besides the lack of water, the soil is also a problem. The soil of the grassland is different from that of other places. There is a layer of “calcium deposit” under the grassland. The roots can not pass through the soil at all, and the texture is very hard. We all know that the roots of shrubs are very tenacious, but even shrubs can’t penetrate this layer of soil. Since trees can’t be deeply rooted in the ground, how can they survive? So just looking at this point, we can’t grow trees on the grassland.
Finally, it’s about temperature. Temperature determines the evaporation rate of water and plays a key role in the growth of trees. The current situation of grassland in China is less precipitation and high temperature, so it is difficult for trees to survive. From the above three points of view, each condition has a fatal limit on the growth of trees on the grassland. In contrast, grass is more suitable for the grassland environment than trees.
In a word, it doesn’t matter whether there are trees on the grassland. What matters is how to make rational use of natural resources and protect it better.