RESUMO
Mineral nutrition in arracacha is a critical production factor that conditions harvest yield. Few studies have been developed in nutrition and physiology, this does not allow to the design of ideal fertilization programs; consequences are increased production costs, soil degradation, and low-quality storage roots. Therefore, this study aimed to characterize the symptoms associated with macronutrient deficiency in arracacha plants and its effect on morphological parameters, the accumulation of fresh and dry biomass, and the distribution of dry matter in the different organs. Under greenhouse conditions, the experiment was conducted in Cajamarca, Tolima, Colombia. A completely randomized design was implemented, with seven treatments and six replicates (6 solutions lacking N, P, K, Ca, Mg, and S and Hoagland complete solution). Forty-two seedlings were transplanted, to which the complete solution was applied for 75 days, increasing the concentrations from 0.25 M to 1 M, and then nutritional deficiencies were induced. Deficiencies caused by macronutrients in arracacha plants exhibited visual symptoms and changes in their morphology. The omission of N, Ca, and S generated the most severe symptoms, drastically affecting plant height, leaf width, number of leaves, and plant mass accumulation. In the case of P, leaves became small and intense green with a violet margin. The Mg and K generated leaves with interveinal and margin chlorosis. Plants with the omission of macronutrients allocated dry mass in the following order: stem, storage roots, propagules, and leaves.
RESUMO
ABSTRACT We present an estimation of the potential species richness of frogs, and diurnal butterflies distributed in the departments of Norte de Santander and Santander, Colombia, and analyze the implications for conservation of such high Andean species. From June 2012 to May 2016, we sampled across the Almorzadero, Santurbán and Tamá biogeographical units to gather presence data of 7 anuran species and 29 butterflies species from the superfamily Papilionoidea. We modeled the potential distribution of each species, converted every model to binary, and the sum up of unique species per cell allowed to estimate the model of potential richness, generating the total number of species for every 1 km2 cell. Every model was validated against field data, vegetation cover, and altitude. Our results suggest the existence of species' concentration zones, specifically in the places of convergence between biogeographical units; it was evident the high levels of data deficiency in some places. Finally, it was clear the importance of these zones as a continuum of biogeographic conditions to maintain the biological diversity.
RESUMEN Presentamos una estimación de la riqueza potencial y las implicaciones para la conservación de especies altoandinas de anuros y de mariposas diurnas, distribuidas en los departamentos de Norte de Santander y Santander. Durante junio de 2012 y mayo de 2016 se realizaron muestreos de campo en las unidades biogeográficas de Almorzadero, Santurbán y Tamá, para registrar los datos de presencia de siete especies de anfibios del orden Anura y 29 de mariposas de la superfamilia Papilionoidea. Realizamos modelamientos de la distribución potencial de cada especie, convertimos cada modelo en binario, y la suma de especies únicas por celda permitió estimar el modelo de riqueza potencial, obteniendo el número total de especies por cada celda de 1 km2; a su vez, los modelos fueron superpuestos sobre información de campo, cobertura vegetal y altitudinal. Nuestros resultados sugieren que existen zonas concretas de concentración de especies en las zonas de convergencia entre las unidades biogeográficas, así como zonas con vacíos de información. Resaltamos la importancia de estas zonas como un continuo de condiciones biogeográficas para mantener la diversidad.