我国热带自然条件的分析及其对农业的影响

Analysis of the Tropical Natural Conditions of China and Their Influence on Agriculture

一热带界线的讨论我国热带范围是目前争论还未解决的问题,由于我国南部(约北纬25°以南)自北而南,自然现象不断发生质变,在质变的地方,常被作为划分热带的依据。由图1可以看出,有5条具有质变意义的界线。

China's tropical regions may be roughly defined as the areas lying South of the latitude 23—25° North.Within almost all these regions,therainfall exceeds 1000 m.m.Average temperatures for the Coldest monthexceed 10℃.and for the hottest month 28℃.Frosting weather occursfor only a very short time during the Winter months and is almostunknown in Southern Kwangtung and Yunnan.The weather is periodicallywet and dry,but the dry season is very pronounced only in YunnanProvince.The tropical soil formed under the monsoon forest and rainforest is immensely fertile,but after the forest destroyed,much of theplant nutrient substance is leached out.The physical conditions mentioned above are in favour of the devel-opment of tropical crops.Southern Kwangtung and Yunnan are bestsuited for developing woody crops such as coconut,oil palm,hevearubber,coffee and island cotton,etc.Other areas are suitable fordevedoping herbaceous crops such as Cymbopogon winterianus.Pineapple,etc.