Effects of Harvest on the Sustainability and Leaf Productivity of Populations of Two Palm Species in Maya Homegardens

Abstract

Traditional management practices are usually thought to be sustainable. The Maya manage Sabal (Arecaceae) palms in homegardens, using their leaves for thatching. The sustainability of such production systems depends on the long-term persistence of palm populations, whereas resource availability also depends on the number of leaves on individual palms. We examined how leaf harvest affects Sabal yapa and S. mexicana population growth rates (λ) and leaf production, comparing traditional and alternative harvest regimes in terms of sustainability and productivity. Demographic, harvest and leaf production data were recorded for three years in two homegardens. We used general integral projection models linked to leaf-production models to describe population dynamics and productivity. Harvest had no effect on S. yapa’s vital rates or on λ, but it changed the growth rate of individuals of S. mexicana, with a negligible impact on λ. Homegardens affected λ values, reflecting the species’ ecological affinities. S. mexicana, introduced from mesic forests, required watering and shade; therefore, its population declined rapidly in the homegarden that lacked both water and shade. The λ of the xerophilic S. yapa was slightly larger without watering than with watering. Palms usually compensated for leaf extraction, causing the number of leaves harvested per individual to increase with harvest intensity. Nevertheless, traditional management is relatively mild, allowing standing leaves to accumulate but reducing the homegarden’s yield. Apparently, the Maya do not seek to maximize annual production but to ensure the availability of large numbers of leaves in homegardens. These leaves may then be used when the entire roof of a hut needs to be replaced every few years.

Chronic leaf harvesting reduces reproductive success of a tropical dry forest palm in northern Mexico

“…In general, previous studies have shown that many palm species are resilient to defoliation [ 9 , 10 ]. However, effects vary among species, and depend on the intensity and frequency of leaf removal [ 11 ].…”

“…Because leaves from a wide range of palm species are economically and/or culturally important, a number of studies have explored the effects of harvest on individuals [ 9 , 10 ], [ 14 ]. Studies have been carried out on species found in both wet and dry tropical and subtropical ecosystems, including species such as Brahea dulcis , Sabal mexicana , S .…”

Ecological, Cultural, and Geographical Implications of Brahea dulcis (Kunth) Mart. Insights for Sustainable Management in Mexico

“…Effects on soil and hydric dynamics in palm groves that are still poorly known need to be assessed. Despite the relevance of Soyate, a further assessment of other palm species in Mexico is needed, such as for the Sabal species which represents an important resource in the warm and humid regions of southeastern Mexico [29,39,40].…”

“…Similarly, as in other countries of South America [23], palms in Mexico have mostly been used as material for construction, food, and the production of tools and utensils of domestic and agricultural use. The palm's leaves, fruits, and apical meristems are the most used parts [21,29,[36][37][38][39][40]. The plant fiber which makes up the leaves is of primary importance in roof thatching and the production of household goods [29,41].…”

“…According to Belcher [16], plant fibers are the most important NTFPs, after medicinal and food plants. In Mexico, the Brahea and Sabal species stand out for their value as plant fiber sources [21,28,29,[36][37][38][39][40][41]. Brahea is of primary importance since it is a predominantly Mexican endemic genus, primarily occurring in dry climates and semiarid environments [42].…”