Once a City, Now a Rain Forest
There are three well- known groups of people who have
played major roles in the history of Central and South
America. The Aztec, who ruled in much of Mexico,
had a highly sophisticated and warlike society. In the
Andes of South America were the Inca, who created
cities such as Machu Picchu. And in Central America,
particularly in the Yucatán Peninsula, were the Maya,
who, for a period of time, converted a land of dense
tropical moist forest into a breadbasket supporting its
thriving cities.
Tikal, now an archeological site in eastern Guatemala,
was a large city of the Classic Period of Mayan
civilization. It provides an example of how secondary
forest reclaims a site after human abandonment.
Located in the Petén region of eastern Guatemala
near the Belize border, Tikal was founded around 600
B.C. and flourished from about A.D. 200 until it was
abandoned around the year 900. Anthropologists are
uncertain as to what combination of climatic and/or
social factors forced the total abandonment of the city
and the subsequent deterioration of Mayan society well
in advance of the Spanish conquest of the Americas. It
is possible that it was a severe, prolonged drought that
initiated Tikal’s eventual decline. What is known is that
when Tikal existed, the land surrounding it was largely
deforested and used for intensive agriculture and
urbanization. At its peak, Tikal served as a major trade
center. Maize (corn), beans, squash, chile peppers,
tomatoes, pumpkins, gourds, papayas, and avocados
were brought from small, widely scattered farms to
be sold in the busy markets of the city. Tikal and its
surroundings replaced tropical moist forest.
An estimated population of 50,000 lived in Tikal,
which spread over an area of 123 km^2 (47.5 mi^2 ),
protected by earthworks and moats. The Classic Mayan
society practiced sophisticated intensive agriculture.
The impressive pyramid- like temples, not excavated
until the 20th century, now serve as silent memorials,
where tourists come to see what remains and to reflect
on the past history of the region. This long- deceased
civilization had developed a calendar as accurate as any
modern calendar, a complex writing system that still
has not been entirely deciphered, and a mathematical
sophistication that included the concept of zero. The
sight of the Great Plaza and Temple I, the Temple of
the Giant Jaguar, enshrouded in the cool early morning
tropical mist, romantically transports the mind’s
eye back to the time when Tikal was a focal point of
civilization in Mesoamerica.
Today what remains of Tikal is enclosed by lush moist
forest (plate 7- 13). Like Mayan ruins throughout the
Yucatán Peninsula, the city itself had to be rediscovered
and excavated, as second- growth forest had literally
grown over and atop the ruins. Much of Tikal, as with
other Mayan ruins, is still hidden under forest, its once
crowded plazas, thoroughfares, and temples overgrown
by epiphyte- laden Breadnut (Brosimum alicastrum),
fig, palm, mahogany (Swietenia species) and Chicle
(Manilkara zapota) trees. From atop the temples, one
can watch spider and howler monkeys cavorting in
the treetops. Agoutis and coatis shuffle through the
picnic grounds, amusing tourists, while searching for
food scraps. Toucans and parrots pull fruits from trees
growing along what were once the central avenues
leading to and from the city. This once great metropolis
was abandoned and then subsequently reclaimed by
lush, second- growth tropical moist forest. What a gap!
Recent studies suggest that Tikal is not an isolated
case of rain forest regeneration. The Darién, a remote
region in southern Panama that is today rich, diverse
rain forest, was subject to extensive human disturbance.
Studies of the pollen and sediment profiles from the
region reveal that much of the landscape had been
planted with corn and subject to frequent fires, probably
set by humans. Only after the Spanish conquest was
the region abandoned. Succession followed. Thus the
lush and seemingly pristine rain forest that defines
the Darién today is only about 350 years old. It’s all
second- growth forest.Resilient Pastures: Succession in
AmazoniaThe global tropics have a long history of human
occupation and anthropogenic deforestation.
Deforestation has dramatically increased in scope
and is of major conservation concern today (chapter
18). Large forested areas of Amazonia have been cut
and converted to pasture (plate 7- 14). What happens
when cattle pastures are abandoned? Does the natural
vegetation reestablish a second- growth forest?
Studies by several research teams in eastern
Amazonia indicate that successional patterns normally
result in the regrowth of forest. Each of the sites in
these Amazonian studies had been cut, burned, and102 chapter 7 if a tree falls . . . rain forest disturbance dynamics