Sustaining Medicinal Barks: Survival and Bark Regeneration of Amphipterygium adstringens (Anacardiaceae), a Tropical Tree under Experimental Debarking

Leonardo Beltrán-Rodríguez,Belinda Maldonado-Almanza,Andrea Martínez-Ballesté,Elizandro Pineda-Herrera,Robert Bye,Juan Ignacio Valdez-Hernández,José Blancas,Mario Luna-Cavazos,Gregorio Ángeles-Pérez,Angélica Romero-Manzanares,José Antonio Sierra-Huelsz,Alfredo Saynes-Vásquez,Tamara Ticktin,Ma Amparo Borja De La Rosa,Sol Cristians

doi:10.3390/su13052860

Abstract

Commercial harvests can threaten tree species harvested for their bark. Amphipterygium adstringens is a dioecious tree, endemic to the tropical dry forests of Mexico, where it is intensively harvested for its medicinal bark. Limited information hinders developing sustainable management strategies for A. adstringens. We assessed bark regeneration for male and female trees, and evaluated the effect of tree sex and diameter, debarking treatments and cutting seasons on bark regeneration and tree survival rates. Bark regeneration was higher for wet season harvested trees (vs. dry), regardless of their sex. Bark regeneration was higher on female than on male trees. There were significant interactions of harvest season, harvest treatment and tree sex diameter on bark regeneration and survival. Overall, the highest bark regeneration rates occurred in female trees with ≥20.1 cm diameter that were wet season harvested with a 50% debarking intensity. Consequently, wet season and intermediate intensity harvests appear to foster sound management, but we recommend against targeting exclusively a single demographic group (i.e., large female trees) due to potential negative impacts on species demography and bark supply. A grounded strategy for sustaining bark harvest would also need to take into account relevant aspects of local socio-ecological context, including harvest interactions with other land uses.

Highlights

Non-timber forest products (NTFPs) are an important component of rural livelihoods [1], and medicinal plants are among the most salient and culturally significant of these resources [2,3]
Tropical dry forest is the dominant ecosystem in the region, which covers more than 90% of the total area, more than half of it is covered by secondary forest patches in different successional stages [26]
A. adstringens had a similar process of bark regeneration in both sexes, regardless of diameter categories and debarking intensities, but some differences were observed between dry and wet season

Summary

Introduction

Non-timber forest products (NTFPs) are an important component of rural livelihoods [1], and medicinal plants are among the most salient and culturally significant of these resources [2,3]. Species life history and the part of the plant that is harvested are major factors that determine NTFP harvest tolerance. Bark harvest can have a high negative impact as it alters the structure and physiological continuity of adult woody plants, threatening their survival [2,3,4]. Because medicinal barks are some of the most traded NTFPs, there is a need to determine their maximum sustainable harvest rates as key elements for their long-term management and conservation for these species [5,6,7]

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Discussion

Conclusion