Well known from the products made from their milky sap, the rubber trees
that dot the floodplain forest provide an important source of food to
fishes and other animals during the annual floods. During the daily few
hours of hot sunlight in the rainy season, the rubber tree's seed capsules
mature and explode, sending the seeds flying into the water. Then, throughout
the high-water season, the floating seeds are gobbled up by animals capable
of cracking or crushing the hard exterior, including large fishes foraging
in the flooded forest, and birds and monkeys, which scoop the seeds out
of the water. Black piranhas split the seed shells with their razor sharp
teeth to eat the kernel inside. Because they digest the seeds, these animals
do not act as dispersers.
Seeds that are not eaten can be carried long distances by the flood-waters.
and they germinate when the floods recede. Tambaqui love rubber tree seeds
so much that they will tear up seedlings to eat the remainder of the nut.
Despite all the predation, rubber trees still are among the most common
trees in the floodplain forest.
In the 1870's people began harvesting the sap from these trees to make
rubber. This caused the Iquitos area of the Amazon basin to grow from
1500 people to nearly 24,000 within a decade. For the next 30 years, Iquitos
was at once an area of great wealth and great poverty. The rubber barons
became quite wealthy while the local rubber tappers were quite poor. This
boom lasted until people began cultivating rubber trees in the Malay Peninsula.