Macrofauna del suelo y condiciones edafoclimáticas en un gradiente altitudinal de zonas cafeteras, Huila, Colombia / Soil macrofauna and edaphoclimatic conditions in an altitude gradient of coffee growing regions, Huila, Colombia

Introducción: La macrofauna del suelo cumple un rol clave en los procesos del suelo, por lo tanto, regula la oferta se servicios ecosistémicos; sin embargo, su nivel de actividad depende en gran parte de las condiciones edafoclimáticas. Objetivo: El presente trabajo evaluó el efecto del gradiente de altitud sobre comunidades de macrofauna del suelo y propiedades edafoclimáticas en zonas cafeteras del Norte del Huila. Métodos: El estudio incluyó 12 lotes de café separados en dos gradientes de altitud: bajo (1 300-1 600 m.s.n.m) y alto (1 600-1 900 m.s.n.m), se recolectó la macrofauna del suelo mediante monolitos (25 x 25 cm a 30 cm de profundidad) y se estudiaron las condiciones edafoclimáticas. Resultados: En total se registró 9 520 individuos m-2 y una riqueza específica de 14 táxones. Las condiciones edafoclimáticas con mayor diferencia estadística entre los gradientes de altitud, fue la temperatura ambiente y humedad relativa con diferencias de 4.9 °C y 10.4 %, respectivamente. Conclusiones: La mayor abundancia de Coleoptera, Hemiptera, Isoptera y Lepidoptera se presentó en sitios más cálidos, es decir a un gradiente de altitud entre 1 300-1 600 m.s.n.m, mientras que Chilopoda y Diplopoda se adaptaron mejor a sitios más fríos en el gradiente altitudinal entre 1 600-1 900 m.s.n.m.

Introduction: Soil macrofauna plays a key role in soil processes and therefore regulates the supply of ecosystem services; however, its level of activity depends largely of the edaphoclimatic conditions. Objective: This work evaluated the effect of altitude gradient on soil macrofauna communities and edafoclimatic properties in coffee zones of North Huila. Methods: The study included 12 coffee lots separated in two altitude gradients: low (1 300-1 600 masl) and high (1 600-1 900 masl). Soil macrofauna was collected by means of monoliths (25 x 25 cm with 30 cm depth) and edaphoclimatic conditions were studied. Results: A total of 9 520 individuals m-2 and a specific richness of 14 taxa were registered. The edaphoclimatic conditions with the greatest statistical difference between altitude gradients were the environmental temperature and relative humidity with differences of 4.9 °C and 10.4 %, respectively. Conclusions: The highest abundance of Coleoptera, Hemiptera, Isoptera, Lepidoptera was presented in warmer sites, that is, altitude gradient 1 300-1 600 masl, while Chilopoda and Diplopoda adapted better to colder sites in altitude gradient 1 600-1 900 m.a.s.l.

Microbial diversity of soils on the banks of the Solimões and Negro rivers, state of Amazonas, Brazil

Analysis of bacterial diversity in soils along the banks of the Solimões and Negro rivers, state of Amazonas, Brazil, was by partial sequencing of the genes codifying the rDNA16S region. Diversity of operational taxonomic units (OTU) and of the divergent sequences obtained were applied in comparative analysis of microbiological diversity in the two environments, based on richness estimators and OTU diversity indices. The higher OTU diversity in the Solimões was based on the higher number of parameters that evoke this. The interaction between the nucleotide sequences of bacteria inhabiting the two riverine environments indicated that the two microrganism communities are similar in composition.