Answer to Question 1
ANSWER: One might think that the soil beneath the forests canopy would be excellent for agriculture. Actually, this is not true. As heavy rain falls on the soil, the water works its way downward, removing nutrients in a process called leaching. Strangely enough, many of the nutrients needed to sustain the lush forest actually come from dead trees that decompose. The roots of the living trees absorb this matter before the rains leach it away. When the forests are cleared for agricultural purposes, or for the timber, what is left is a thick red soil called laterite. When exposed to the intense sunlight of the tropics, the soil may harden into a bricklike consistency, making cultivation almost impossible.
Answer to Question 2
ANSWER: Within the tropical wet climate (Af), seasonal temperature variations are small (normally less than 3C) because the noon Sun is always high and the number of daylight hours is relatively constant. However, there is a greater variation in temperature between day (average high about 32C) and night (average low about 22C) than there is between the warmest and coolest months. This is why people remark that winter comes to the tropics at night.
The relative sizes of inorganic soil components.
Plant adaptations for salty conditions.
Agriculture, 1860
The level of emissions from transport in the United States is twice as high as the global average
Response of corn selected for high and low oil content over 76 generations
plant diagram