Master En Ciencias Ambientales

From Mayan to Modern exploitation of Chicozapote (Manilkara zapota): effects on population structure

Daniela Marini

Introduction
Culture does not necessarily destroy nature. Actually, human relations with the environment can not only sustain, but potentially even enhance, its integrity (Dove et al. 2005). However, a positive interaction with the environment can only be achieved when ourinterventions are based on a thoughtful understanding of the ecology of the species being used. The controlled harvesting of non-timber forest products can have lower impacts on forest ecosystems than other uses, provide a range of social and economic benefits to local groups, and is potentially compatible with efforts to integrate the use and conservation of biodiversity. In particular, theextraction of plant exudates (latexes, resins and gums) probably comes to the closest to conforming the ideal of sustainable non-timber forest product extraction (Peters 1994). However, in actual practice, the exploitation of plant exudates can be very destructive. Resinous trees can be tapped repeatedly and provide exudates for several years, but felling trees to obtain the resins is a commonpractice throughout the tropics. This is done to facilitate and accelerate the process of resin extraction, or when there are no visible signs that indicate whether a tree contains valuable resin or not (Peters 1994). Chicozapote (Manilkara zapota (L.) Royen (Sapotaceae)) is a common example of plant exudates that is tapped in a non-destructive fashion. The chiclero, the man who tap the Chicozapotetree, makes a V shaped cut in the bark at the bottom of the tree trunk, gradually taking the incision higher and higher, until he has to climb the tree, suspended by ropes. Eventually the cuts ascend to the forest canopy, forming a 'zigzag' design from the crown of the tree to the base below. A canvas pouch or bag is placed at the bottom of the tree, and the bag collects the latex during the next 20hours or so (Forero et al. 2007).

Chicozapote grows largely in the tropical semi-evergreen forest of Yucatan peninsula in Mexico and in the Gran Petén region of Belize and Guatemala. In the Yucatan peninsula, following the decline of the Mayas, and their eventual conquest by Spaniards, various forms of forest resource extraction took place, gradually increasing in intensity to the present.The long history of Chicozapote utilization has led to significant alteration of its population structure, expressed as a deviation from size-distributions patterns resulting from trees which were more than normally logged, tapped, harvested, or affected by an extended dry period (Gomez-Pompa 1987). Changes in the structure of chicle population became visible after the development of the chewinggum industry (Shanley et al. 2002). However, M.zapota is still one of the most abundant species in the lowland forests of the Yucatan Peninsula (Gomez-Pompa 1987, Cruz-Rodríguez et al. 2004, Wetering et al. 2008). In light of the changing history of chicozapote exploitation in the Yucatan peninsula, the purpose of this paper is to examine the current population structure of this species.Traditional use of chicozapote
Although chicle is recognized to have been a significant part of both the Aztec and the Maya cultures, almost no information regarding how the plant was used by these people is documented (Shanley et al. 2002). The influence of the Maya on the structure of present-day forests of the Yucatan Peninsula and Petén Basin are not entirely known. However, it is well documentedthat population levels were much higher for the region than they were when the when the colonist arrived, and that probably vast areas of forest were cleared in order to cultivate land for the production of food (Hartshorn 1980). Chicle was extracted by a well established forest culture, with a considerable knowledge and experience. The effect of forest clearing during the Mayan period on the...