Variación arquitectónica y morfológica de Hintonia latiflora (Rubiaceae) en relación a la cosecha de corteza y factores ambientales

Abstract

Architectural and morphological variation of Hintonia latiflora (Rubiaceae) in relation to bark harvest and environmental factors. Hintonia latiflora is a rare ecologically and economically important species from the Tropical Deciduous Forest of the Balsas Basin, Mexico, whose bark is traded as medicinal. Debarking practices have modified the shape of plants, their architecture and morphometry; but it is unknown if some topographic and edaphic factors may also influence in these attributes. Here we propose that the ecological conditions of this species distribution and harvesting areas, may determine the morphometric characteristics and the individuals variation in their architecture. To test this hypothesis we assessed the relationship of topographic and edaphic factors on the morphological characteristics of saplings (n = 143) and adults (n = 117), in eight harvesting areas of H. latiflora. The harvesting areas, with a surface of 0.6 ha, were selected randomly with the support of participatory mapping elaborated by gatherers of the study site. Data were analyzed using principal components (PCA) and canonical correspondence (CCA) analyses. The first three PC explained 92.1 % of the morphological variation; height, basal diameter, and coverage, explained morphometric differences in both, saplings and adults, in all eight harvesting zones. The terrain slope, slope orientation, soil depth and stoniness, were ecological factors statistically related with morphometric differences. A lower terrain slope, little stoniness, soil depth, slope orientation E-W in saplings (azimuth 90˚-270˚) and N-S in adults (azimuth 0˚-180˚) were the factors associated to height, number of basal branches, basal diameter and coverage of H. latiflora. Areas with higher harvesting intensity were composed by monopodic trees and some reiterated basitone individuals; the adults of these areas also had more fruits. At these sites, plants of H.latiflora were more abundant and produced more bark, but the high-intensity of harvesting, changes plant architecture, forming shrubby, multi-stemmed individuals, that originally were mesotone trees. Areas with lower harvesting intensity were characterized by steep slopes, shallow and rocky soils, and were dominated by basitone trees of smaller size, thin and scarce in the area. These sites are the least recommended for harvesting, because they produce less bark per tree, and serve to preserve the species at the site. Based on these results, we can develop restoration programs in areas affected by commercial harvesting, establish forestry plantations in key sites to ensure the establishment and development of individuals with desirable characteristics for bark harvesting and contribute to in situ conservation of H. latiflora in the Alto Balsas Basin. Rev. Biol. Trop. 65 (3): 900-916. Epub 2017 September 01.

Morphological Variation in Scarlet Plume (Euphorbia fulgens Karw ex Klotzsch, Euphorbiaceae), an Underutilized Ornamental Resource of Mexico with Global Importance

“…Other factors that were not analyzed in this study but have been observed to have an impact on morphometric variation of vegetative and reproductive structures, were ground slope, soil depth, stony soil, temperature, wind speed, rain, and relative humidity [29,30]. In contrast, in other studies conducted in members of the genus Opuntia, it was determined that phenotypic differences in cladodes between populations were more related to population density than environmental factors [31].…”

¿El descortezamiento de un árbol medicinal impacta en su estructura poblacional-espacial? El caso de Hintonia latiflora en México

“…Hintonia latiflora es una especie leñosa, iterópara y hermafrodita, protándrica y hercógama, polinizada por lepidópteros nocturnos y quirópteros, con dispersión anemócora y barócora (Beltrán-Rodríguez et al, 2015). Los individuos son reproductivos a partir de 8 cm de diámetro basal y, en estos, sus dimensiones alométricas van de 15 cm a 40 cm en diámetro basal, 6 m a 8 m de altura y ancho de copa de 3.5 m a 6.5 m, con una producción promedio de corteza en peso seco que oscila entre 500 g y 4 kg por individuo (Beltrán-Rodríguez et al, 2017b). Esta especie es endémica del bosque tropical caducifolio de México y Centroamérica (Lorence y Taylor, 2011), y presenta poblaciones aisladas con baja densidad de individuos reproductivos (5 ind.…”

“…El área está conformada por parches de vegetación compuestos por campos agrícolas y bosques secundarios en las planicies próximas al Río Balsas, así como bosques primarios relativamente bien conservados en las zonas montañosas más alejadas. La vegetación dominante es bosque tropical caducifolio con predominio de las familias Fabaceae, Burseraceae y Poaceae, pero también hay Matorral Xerófilo tipificado por cactáceas columnares (Beltrán-Rodríguez et al, 2017b).…”

“…Hintonia latiflora (Rubiaceae) "quina amarilla" o "copalchi" es uno de los RFNM más vulnerables en México por el descortezamiento comercial (Beltrán-Rodríguez, Romero-Manzanares, Luna-Cavazos y García-Moya, 2017b). Algunos estudios han demostrado que la cosecha de corteza en los árboles de quina modifica el modelo arquitectónico (mesótono vs basítono), patrón morfométrico (diámetro basal, grosor corteza y altura de la planta) y en el caso de la población, reduce la densidad (Beltrán-Rodríguez et al, 2015;Beltrán-Rodríguez et al, 2017b); pero se desconoce su efecto en cuanto a los cambios de la estructura poblacional cuando las plantas están sujetas o no a descortezamiento parcial o total, así como los efectos que estas prácticas pueden tener en la organización espacial de los individuos de estas poblaciones.…”

Pod production, and dasometric variables, of the tree Senna spectabilis (Fabaceae) in a tropical dry forest

“…The knowledge of the tree architecture and dasometric measurements represents a contribution to defining criteria for harvesting and management (Beltrán-Galindo, Romero-Manzanares, Luna-Cavazos, & García-Moya, 2017) and the design of agroforestry or silvicultural systems. The architecture of the tree canopy has significant impacts on the microclimate of the crop and is influenced by competition for light, water absorption and transpiration, dispersion of pollen; acquisition and location of carbon (Boudreau, 2013).…”