Potential impact of harvesting on the population dynamics of two epiphytic bromeliads

作者：Toledo Aceves Tarin^*; Hernandez Apolinar Mariana; Valverde Teresa

来源：Acta Oecologica, 2014, 59: 52-61.

DOI：10.1016/j.actao.2014.05.009

• Demography
• Elasticity
• Life table response experiments (LTRE)
• Non-timber forest products (NTFP)
• Population matrix models
• Retrospective analysis
• Tillandsia multicaulis
• Tillandsia punctulata

Large numbers of epiphytes are extracted from cloud forests for ornamental use and illegal trade in Latin America. We examined the potential effects of different harvesting regimes on the population dynamics of the epiphytic bromeliads Tillandsia multicaulis and Tillandsia punctulata. The population dynamics of these species were studied over a 2-year period in a tropical montane cloud forest in Veracruz, Mexico. Prospective and retrospective analyses were used to identify which demographic processes and life-cycle stages make the largest relative contribution to variation in population growth rate (lambda). The effect of simulated harvesting levels on population growth rates was analysed for both species. lambda of both populations was highly influenced by survival (stasis), to a lesser extent by growth, and only slightly by fecundity. Vegetative growth played a central role in the population dynamics of these organisms. The lambda value of the studied populations did not differ significantly from unity: T. multicaulis lambda (95% confidence interval) = 0.982 (0.897-1.060) and T. punctulata lambda = 0.967 (0.815-1.051), suggesting population stability. However, numerical simulation of different levels of extraction showed that lambda would drop substantially even under very low (2%) harvesting levels. Matrix analysis revealed that T. multicaulis and T. punctulata populations are likely to decline and therefore commercial harvesting would be unsustainable. Based on these findings, management recommendations are outlined.

• 出版日期2014-8