生物圈是人类生存的大环境,其基本要素由植物构成,植物沟通了人与大气圈和岩石圈的联系,起着嫁介作用;同时人们的衣、食、住、行,都直接或间接地取之于植物。然而,由于历史上不合理地放牧及乱垦草原,乱砍滥伐森林,我国森林复被率日趋下降,目前仅为12％。其结果:水土流失日趋严重,土壤退化、沙化不断扩大;原来大量保水田失去了水源灌溉;许多山泉水河断流干涸,甚至出现了光山秃岭,满目苍夷的状态。历史的教训深刻表明:植物是人类协调自然的主要工具,人类可以利用植物改善环境,增加生产,取得生态系统长期稳定的平衡,但人类也可以成为破坏者。为了维护生态系统的平衡,其措施应以生物 Biosphere is the environment of human existence, its basic elements are composed of plants, plants communicate with the atmosphere and the lithosphere, and play a role in marriage; at the same time, people’s clothing, food, shelter, transportation, directly or indirectly Take the plant. However, due to the unreasonable grazing and indiscriminate cultivation of grasslands and the deforestation of deforestation, the rate of forest rehabilization in our country has been declining. At present, it is only 12%. As a result, soil and water loss became more and more serious, soil degradation and desertification continued to expand. As a result, a large number of paddy fields had lost water irrigation. Many mountain spring rivers dried up, and even bare mountain bald appeared. Historical lessons have profoundly demonstrated that plants are the main tools for mankind to coordinate nature. Mankind can make use of plants to improve the environment, increase production and achieve a long-term stable balance of ecosystems. However, humans can also become spoilers. In order to maintain the balance of the ecosystem, its measures should be biological