0 one of the two imaginary lines around the earth at approximately 23.5 degrees north and 23.5 degrees south of the equator --
Both traits showed geographic variation and strong non-linear clines with a sharp reduction in size in the tropics.
In the tropics, for example, age determination on a broad scale - especially with so many species, is simply beyond the reasonable reach of analysts.
In the nineteenth century some people in the tropics took opium believing that it would be effective against malaria.
Maesopsis continues to be introduced as a rapid-growing timber species in plantations throughout the tropics.
Parasitic organisms are found in almost every environment ranging from the extremes of cold conditions in the polar regions to hot climates in the tropics.
Low soil water availability decreases decomposition rates in the dry sub-humid and semi-arid tropics despite their higher temperatures.
Therefore, soil moisture conservation is crucial for maintaining soil biological processes in smallholder cropping systems, especially in sub-humid and semi-arid tropics.
Successful establishment of seedlings in the dry tropics is dependent mainly upon moisture availability.