Differential response in the acicular anatomy of Pinus caribaea var. Caribaea and Pinus tropicalis (Pinaceae) in sympatry

Abstract

Pinus caribaea var. caribaea and Pinus tropicalis are the two species of the genus Pinus that form the pine forests of western Cuba, either in pure stands or in sympatry. The objective of this study is to evaluate the differential response in foliar anatomy of both species in the same ecotopes. Cross sections of the needles were made and 12 anatomical variables were measured. The statistical analyzes used, allowed to clearly differentiate the two species, each one presents its own variations to adapt to the same environment. The Mann-Whitney test showed that there are differences in nine of the 12 anatomical variables between the two species in each ecotope and only those variables related to photosynthesis and transport were similar between species. Discriminant analysis showed that each population of the same species is ordered in the opposite way with respect to the other. The variables that contribute to the discrimination between the species are the number of stomata, thickness of the epidermis, thickness of the cuticle and number of resin channels. Both species present a differential response in their anatomical variables to similar ecotope conditions that are adaptive responses and not anatomical adjustments.

Keywords

• variación anatómica foliar
• respuesta diferencial
• pinus tropicalis
• simpatría.