PARENT SESSION
Poster Session 36: Genetics / Population Ecology
Thursday, August 11, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

Applying retrospective demographic models to assess sustainable use: The Maya management of Sabal palms.

Martínez-Ballesté, Andrea^*,1, Martorell, Carlos ², Martínez-Ramos, Miguel³, Caballero, Javier¹, ¹ Jardin Botanico Exterior, Universidad Nacional Autonoma de Mexico, Mexico, D.F., Mexico² Facultad de Ciencias, Universidad Nacional Autonoma de Mexico., Mexico, D.F., Mexico³ Centro de Investigaciones en Ecosistemas, Universidad Nacional Autonoma de Mexico., Morelia, Michoacan, Mexico

ABSTRACT- Sabal palm has been managed for over 3000 years by the Yucatec Maya of Mexico. The most important use of Sabal leaves is that for thatching the traditional Maya house. In the Yucatan peninsula this palm has been introduced to pasturelands, maize fields (milpas), and homegardens. These and other traditional management systems are usually believed to be sustainable, but there still little evidence to support this hypotesis. Demographic models have been used for this purpose, mainly focusing on the population growth rate . So far, retrospective analysis has not been applied, even though it examines how the differences induced by management in the life cycle of a species affect its . In this study we assess whether ecologically sustainable use of Sabal takes place in homegardens, pasturelands and milpas, and if so, how is it achieved. We constructed matrix population models for four populations of Sabal that were followed for three years, and we conducted a retrospective analysis on them. Management in homegardens seems to be oriented to increasing availability of Sabal leaves, favouring survival of seedlings and increasing the density of harvestable-sized palms. On the contrary, in the milpa and the pastureland the population size-structure resembles that of unmanaged populations. Our values suggest that the traditional use of Sabal in all the studied management regimes is sustainable. Nevertheless, the processes that lead to sustainable use are different in each system as shown by our retrospective analysis. While fecundity contributes positively to only in homegardens, permanence and growth maintain palm population at equilibrium in the pastureland and in the milpa, respectively. Between-year climatic differences had a smaller impact in than management practices, which may vary from one year to another, leading to different balances in the sustainable use of the populations involved. Even though no significant differences were found on values, Maya achieve sustainable use of Sabal yapa under diverse scenarios by managing the great plasticity of the species, as was revealed by the retrospective analysis. Hence, this approach has proved to be effective, not only for assessing sustainable use, but also for understanding the factors that favour or limit it.

Key words: Ethnoecology, LTRE, Sabal yapa, Traditional management