Efecto de la deforestación ribereña sobre la materia orgánica particulada gruesa en quebradas con influencia ganadera de la región Andina de Colombia / Effect of riparian deforestation on coarse particulate organic matter in streams with livestock influence in the Andean region of Colombia

Introducción: La materia orgánica particulada gruesa originada en la vegetación ribereña es la fuente principal de energía en muchas cuencas de cabecera. Sin embargo, la transferencia de dicha materia es alterada por la destrucción de los bosques. Objetivo: Evaluar diferencias en la materia orgánica en quebradas con bosques y con pastizales. Métodos: Comparar las entradas, el almacenamiento y la exportación de esta materia orgánica en el cauce de quebradas con bosques y con pastizales, en la región central de los Andes de Colombia. En cada quebrada, se midieron los aportes verticales y laterales de hojarasca con canastas; hojarasca del lecho de las quebradas con cuadrantes, y la exportación de material con redes de deriva, con un alcance de 100 m. Resultados: Las quebradas con bosques ribereños recibieron un promedio anual de 915 g m-2 de materia orgánica particulada gruesa, exportando un total de 334 g m-3 y almacenando 732 g m-2, valores que fueron significativamente más altos que en quebradas con pastizales, donde los valores correspondientes fueron: 125.4 g m-2; 128 g m-3 y 205.5 g m-2. Conclusiones: La remoción de cobertura boscosa de la zona ribereña reduce la materia orgánica en estas cuencas de cabecera en Colombia.

Introduction: Coarse particulate organic matter originated in riparian vegetation is the main source of energy in many headwater streams. However, the transfer of such material is altered by the destruction of forests. Objective: To assess flow differences of this organic matter in streams with forests and grasslands. Methods: We compared input, storage and export of this organic matter in the riparian belts of streams with forests, and streams with grasslands, in the central Andean region of Colombia. For each stream, we measured vertical and lateral litter with baskets; stream bed litter with a quadrant, and matter export with drift nets, in a 100 m reach. Results: The streams with riparian forest received an average of 915 g m-2 of coarse particulate organic matter annually, exported a total of 334 g m-3 and stored 732 g m-2, values that were significantly higher than in grassland streams, where the corresponding values were: 125.4 g m-2; 128 g m-3 and 205.5 g m-2. Conclusions: The removal of tree cover from the riparian zone reduced the organic matter in these headwater streams of Colombia.

Sensibilidad de Elmidae (Insecta: Coleoptera) a la perturbación delhábitat y la calidad fisicoquímica del agua en ambientes lóticos de los Andes colombianos

Introducción: Los élmidos son organismos acuáticos frecuentemente asociados con aguas corrientes, limpias y bien oxigenadas. Sin embargo, algunos géneros de esta familia también se encuentran en aguas moderadamente contaminadas, lo cual puede ser un reflejo de su tolerancia a algún grado de deterioro del hábitat. Objetivo: Determinar la sensibilidad o tolerancia a la contaminación y los principales factores que influyen en la presencia y composición taxonómica de Elmidae en microcuencas colombianas. Métodos: Se muestrearon 60 localidades entre 450 y 4 000 msnm, principalmente en la región Andina, los muestreos se realizaron entre 2002 y 2013 con 70 eventos no simultáneos en cinco zonas. En un transecto de 100 m, se registraron datos físico-químicos, bacteriológicos y de calidad del hábitat (ICH), se hicieron arrastres con red D y Surber, y se determinaron los géneros de Elmidae. Se realizó un Análisis de Correspondencia Canónica entre las variables ambientales y la composición de Elmidae, las relaciones significativas se confirmaron con una prueba de Mantel y se realizó una prueba Mantel parcial incluyendo la ubicación geográfica como tercera matriz. Se calcularon los Índices de Contaminación ICOs y de Calidad de Agua ICA-FSN y se definieron intervalos de aparición de géneros para variables ambientales e índices. Para obtener las significancias estadísticas, se realizaron Análisis de Varianza ANOVA, pruebas t de Student y Modelos Lineales Generalizados MLG con distribución Poisson. Resultados: Se encontraron 22 géneros y 15 especies que representan el 78.5 % de la riqueza nacional conocida. Tyletelmis y las especies Gyrelmis pusio, G. simplex, Xenelmis sandersoni, X. leechi, X. granatoides y X. teres, corresponden a nuevos registros para Colombia. Los principales factores que influyeron en la riqueza y composición de Elmidae fueron: saturación de oxígeno, deposición de sedimentos,sólidossuspendidos, disponibilidad de sustratos, altura, ubicación geográfica, conductividad, alcalinidad, turbidez, nitratos, nitrógeno amoniacal y fósforo. Conclusiones: Los géneros de Elmidae difieren en su tolerancia a la contaminación y, por lo tanto, no pueden ser clasificados bajo el mismo grado de sensibilidad. Esta información puede ser útil para la clasificación de los géneros de Elmidae de acuerdo con su sensibilidad a los cambios en las condiciones ambientales y la degradación del hábitat, lo cual será un primer paso para la incorporación en un índice biótico de calidad de agua adaptado para las condiciones locales o el ajuste de los índices preexistentes.

Introduction: Riffle beetles are aquatic organisms frequently associated with well-oxygenated clean running water. However, some genera of Elmidae can also be found in moderately polluted streams proving their tolerance to certain degree of habitat degradation. Objective: To determine the pollution sensitivity and tolerance of each genus of Elmidae in Colombian streams, and the main factors that influence its presence and taxonomic composition. Methods: Sixty locations between 450 and 4 000 m.a.s.l. were sampled, mainly in the Andean Region of Colombia. Collection was carried out between 2002 and 2013 with 70 non-simultaneous events in five zones. In a 100 m transect, physicochemical, bacteriological and environmental quality information was recorded. Samples of Elmidae were collected with D and Surber nets and determined taxonomically. A Canonical Correspondence Analysis of the Elmidae assembly and environmental data was carried out, significant relationships were confirmed with a Mantel test and a partial Mantel test was carried out including the geographic location as the third matrix. The Pollution (ICO) and Water Quality (ICA-NSF) Indices were calculated, and the occurrence intervals by genus were plotted for environmental variables and indices. Analysis of Variance ANOVA, Student's t-test and Generalized Linear Models GLM with Poisson distribution, were calculated in order to establish the significance of the results. Results: Twenty-two genera and 15 species were found in the evaluated streams; which represent 78.5 % of known national generic richness. Tyletelmis and the species Gyrelmispusio, G. simplex, Xenelmis sandersoni, X. leechi, X. granatoides and X. teres correspond to new records for Colombia. The most important factors influencing the presence and composition of Elmidae were: oxygen saturation, sediment deposition, suspended solids, epifaunal substrate availability, altitude and geographic location, conductivity, turbidity, alkalinity, nitrates, ammonia nitrogen and phosphorus. Conclusions: The genera of Elmidae differ in their tolerance to contamination and therefore cannot be classified in the same degree of sensitivity. This information can be useful for classifying genera of Elmidae according to their sensitivity to changes in environmental conditions and habitat degradation, which will be a first step to incorporate Elmidae in water quality biotic indices adapted to local conditions or to adjust preexisting indices.

Influencia de la ganadería en los macroinvertebrados acuáticos en microcuencas de los Andes centrales de Colombia / Cattle raising influence over the aquatic macroinvertebrates in microbasins of central Andes, Colombia

Resumen En Colombia la actividad ganadera es de gran importancia para la economía rural y la oferta alimentaria del país. Con el fin de determinar el impacto de la ganadería y de los corredores ribereños sobre la comunidad de macroinvertebrados acuáticos en microcuencas Andinas, se seleccionaron nueve fuentes de agua de cabecera en el municipio de Villamaría (Caldas, Colombia), cinco de ellas con bosques ribereños y cuatro totalmente desprotegidas. En cada quebrada durante junio 2013 se recolectaron macroinvertebrados acuáticos usando una red D y una Surber, se tomaron muestras de agua, se midieron características del cauce y se determinó el índice de calidad de hábitat. En total se recolectaron 98 934 individuos distribuidos en nueve clases, 17 órdenes, 56 familias y 92 géneros. Veneroida fue el orden que presentó mayor abundancia seguido de Trichoptera, Diptera, Tubificida y Ephemeroptera. Coleoptera fue el orden que presentó mayor riqueza de géneros con 28, seguido de Diptera con 18, Trichoptera con 11, Ephemeroptera con 10 y Odonata con ocho. Las quebradas con corredor ribereño fueron significativamente más profundas, tuvieron mayor proporción de grava e Índice de Calidad de Hábitat y presentaron mayor riqueza de géneros que las quebradas desprotegidas (P < 0.05). Los géneros Acrobis, Ferrisia, Eurygerris, Heleobia y Pisidium, el nitrógeno total, el nitrógeno amoniacal y la proporción de limo, estuvieron correlacionados con las quebradas sin bosques ribereños, mientras que el género Rhagovelia, la subfamilia Chironominae, el índice de calidad de hábitat y la proporción de grava y piedras se correlacionaron con arroyos que tienen bosques ribereños. Los resultados de este estudio confirman que la presencia de bosques en zonas de ribera ayuda a amortiguar el impacto negativo que generan las prácticas ganaderas sobre las microcuencas y mejoran los servicios ambientales que estas prestan, por lo que se recomienda mantener la franja de vegetación ribereña en arroyos que la poseen y permitir el establecimiento de esta en arroyos desprovistos de bosque en sus las laderas.

Abstract In Colombia, livestock activity is of great importance for the rural economy and the country's food supply. In order to measure the impact of cattle raising and riparian corridors on the composition and diversity of benthic macroinvertebrates in Andean microbasins, nine headwater streams were selected in the municipality of Villamaría (Caldas, Colombia), five of them with riparian corridors and four without protection. During July 2013, macroinvertebrate samples were collected using D-net and Surber nets, and each streams was characterized according to water quality, channel metrics and habitat quality score. In total 98 934 individuals were collected, distributed in nine classes, 17 orders, 56 families and 92 genera. Veneroidea was the most abundant order followed by Trichoptera, Diptera, Tubificida and Ephemeroptera. Coleoptera was the richest order with 28 genera, followed by Diptera with 18, Trichoptera with 11, Ephemeroptera with 10 and Odonata with 8. Streams with riparian corridors were deeper, had higher proportion of coarse substrates and Habitat Quality Score and presented higher genus diversity than those unprotected (P < 0.05). The genera Ferrisia, Eurygerris, Heleobia and Pisidium; total nitrogen, ammonia nitrogen and silt proportion on the streambed were correlated with unprotected streams, whilst the genus Rhagovelia, the subfamily Chironominae, the Habitat Quality Score and the proportion of coarse substrates were correlated with streams with riparian corridors. This information confirms that riparian corridors help reducing the negative impact generated by cattle ranching practices and improve the provision of environmental services, and therefore it is recommended to maintain or restore the strip of riparian vegetation to protect the streams in cattle ranching landscapes. Rev. Biol. Trop. 66(3): 1244-1257. Epub 2018 September 01.

[Differential effects of attention deficit/hyperactivity disorder subtypes in event-related potentials]. / Efecto diferencial del subtipo clínico en los potenciales evocados cognitivos de pacientes con déficit de atención e hiperactividad.

BACKGROUND: To better understand the neurophysiological substrates in attention deficit/hyperactivity disorder (ADHD), a study was performed on of event-related potentials (ERPs) in Colombian patients with inattentive and combined ADHD. METHODS: A case-control, cross-sectional study was designed. The sample was composed of 180 subjects between 5 and 15 years of age (mean, 9.25±2.6), from local schools in Manizales. The sample was divided equally in ADHD or control groups and the subjects were paired by age and gender. The diagnosis was made using the DSM-IV-TR criteria, the Conners and WISC-III test, a psychiatric interview (MINIKID), and a medical evaluation. ERPs were recorded in a visual and auditory passive oddball paradigm. Latency and amplitude of N100, N200 and P300 components for common and rare stimuli were used for statistical comparisons. RESULTS: ADHD subjects show differences in the N200 amplitude and P300 latency in the auditory task. The N200 amplitude was reduced in response to visual stimuli. ADHD subjects with combined symptoms show a delayed P300 in response to auditory stimuli, whereas inattentive subjects exhibited differences in the amplitude of N100 and N200. Combined ADHD patients showed longer N100 latency and smaller N200-P300 amplitude compared to inattentive ADHD subjects. CONCLUSIONS: The results show differences in the event-related potentials between combined and inattentive ADHD subjects.

Efecto diferencial del subtipo clínico en los potenciales evocados cognitivos de pacientes con déficit de atención e hiperactividad / Differential effects of Attention deficit/hyperactivity disorder subtypes in event-related potentials

Introducción: Con el fin de mejorar el conocimiento de las bases neurofisiológicas del trastorno por déficit de atención e hiperactividad (TDAH) se realizó un estudio de potenciales evocados cognitivos en pacientes colombianos con TDAH combinado y TDAH inatento. Métodos: Estudio no experimental, de casos y controles y corte transversal, con una muestra conformada por 180 niños (n -132) y niñas (n-48), entre 5 y 15 (media, 9,25 ± 2,6) años de edad, pertenecientes a instituciones educativas de la ciudad de Manizales. Se dividió a los sujetos en un grupo con diagnóstico de TDAH y otro de control apareados por edad y sexo. Los sujetos fueron evaluados con los criterios del DSM-IV-TR, test de Conners, WISC-III y entrevista psiquiátrica estructurada MINIKID. Se realizó una revisión médica y se tomaron los potenciales evocados relacionados con eventos en modalidad visual y auditiva de atención pasiva (sin respuesta motora) dentro del paradigma oddball. Resultados: Los sujetos con TDAH presentaron diferencias en la amplitud N200 y latencia P300 en la modalidad auditiva y en la amplitud N200 en la modalidad visual. El subtipo clínico combinado mostró prolongación de la latencia de P300 en Fz, Cz y Pz en la tarea auditiva. El subtipo inatento mostró diferencias en la amplitud de la onda N200 y N100. Al comparar estos dos subtipos en la modalidad auditiva, el subtipo combinado tuvo mayor latencia de N100 y menor amplitud de P300 en Pz. Conclusiones: Los resultados indican una modulación diferencial de los componentes de los potenciales evocados cognitivos entre TDAH combinado y TDAH inatento.

Background: To better understand the neurophysiological substrates in attention deficit/hyperactivity disorder (ADHD), a study was performed on of event-related potentials (ERPs) in Colombian patients with inattentive and combined ADHD. Methods: A case-control, cross-sectional study was designed. The sample was composed of 180 subjects between 5 and 15 years of age (mean, 9.25 ± 2.6), from local schools in Manizales. The sample was divided equally in ADHD or control groups and the subjects were paired by age and gender. The diagnosis was made using the DSM-IV-TR criteria, the Conners and WISC-III test, a psychiatric interview (MINIKID), and a medical evaluation. ERPs were recorded in a visual and auditory passive oddball paradigm. Latency and amplitude of N100, N200 and P300 components for common and rare stimuli were used for statistical comparisons. Results: ADHD subjects show differences in the N200 amplitude and P300 latency in the auditory task. The N200 amplitude was reduced in response to visual stimuli. ADHD subjects with combined symptoms show a delayed P300 in response to auditory stimuli, whereas inattentive subjects exhibited differences in the amplitude of N100 and N200. Combined ADHD patients showed longer N100 latency and smaller N200-P300 amplitude compared to inattentive ADHD subjects. Conclusions: The results show differences in the event-related potentials between combined and inattentive ADHD subjects.

[Agricultural land use impacts on aquatic macroinvertebrates in small streams from La Vieja river (Valle del Cauca, Colombia]. / Impacto del uso del suelo agropecuario sobre macroinvertebrados acuáticos en pequeñas quebradas de la cuenca del río La Vieja (Valle del Cauca, Colombia).

The expansion of the agricultural frontier in Colombia has exerted significant pressure on its aquatic ecosystems during the last few decades. In order to determine the impacts of different agricultural land uses on the biotic and abiotic characteristics of first and second order streams of La Vieja river watershed, we evaluated 21 streams located between 1,060 and 1,534 m asl in the municipalities of Alcalá, Ulloa, and Cartago (Valle del Cauca, Colombia). Seven streams were protected by native vegetation buffers, eight had influence of coffee and plantain crops, and six were influenced by cattle ranching. Habitat conditions, channel dimensions, water quality, and aquatic macroinvertebrates were studied in each stream. Streams draining cattle ranching areas had significantly higher dissolved solids, higher phosphorus, higher alkalinity, higher conductivity, and lower dissolved oxygen than those covered by cropland and forests. Coarse substrates and diversity of flow regimes were significantly higher in cropland and protected streams when compared to streams affected by cattle ranching, whereas the percent of silt and slow currents was significantly higher in the latter. A total of 26,777 macroinvertebrates belonging to 17 orders, 72 families and 95 genera were collected. The most abundant groups were Diptera 62.8%, (Chironomidae 49.6%, Ceratopogonidae 6.7%), Mollusca 18.8% (Hydrobiidae 7.2%, Sphaeriidae 9.6%) and Trichoptera 5.7% (Hydropsychidae 3.7%). The Ephemeroptera, Trichoptera, and Plecoptera orders, known for their low tolerance to habitat perturbation, had high abundance in cropland and forested streams, whereas Diptera and Mollusca were more abundant in those impacted by cattle ranching. Results indicate that streams draining forests and croplands have better physical and biological conditions than those draining pastures, and highlight the need to implement protective measures to restore the latter.

Impacto del uso del suelo agropecuario sobre macroinvertebrados acuáticos en pequeñas quebradas de la cuenca del río La Vieja (Valle del Cauca, Colombia)

Agricultural land use impacts on aquatic macroinvertebrates in small streams from La Vieja river (Valle del Cauca, Colombia). The expansion of the agricultural frontier in Colombia has exerted significant pressure on its aquatic ecosystems during the last few decades. In order to determine the impacts of different agricultural land uses on the biotic and abiotic characteristics of first and second order streams of La Vieja river watershed, we evaluated 21 streams located between 1 060 and 1 534 m asl in the municipalities of Alcalá, Ulloa, and Cartago (Valle del Cauca, Colombia). Seven streams were protected by native vegetation buffers, eight had influence of coffee and plantain crops, and six were influenced by cattle ranching. Habitat conditions, channel dimensions, water quality, and aquatic macroinvertebrates were studied in each stream. Streams draining cattle ranching areas had significantly higher dissolved solids, higher phosphorus, higher alkalinity, higher conductivity, and lower dissolved oxygen than those covered by cropland and forests. Coarse substrates and diversity of flow regimes were significantly higher in cropland and protected streams when compared to streams affected by cattle ranching, whereas the percent of silt and slow currents was significantly higher in the latter. A total of 26 777 macroinvertebrates belonging to 17 orders, 72 families and 95 genera were collected. The most abundant groups were Diptera 62.8%, (Chironomidae 49.6%, Ceratopogonidae 6.7%), Mollusca 18.8% (Hydrobiidae 7.2%, Sphaeriidae 9.6%) and Trichoptera 5.7% (Hydropsychidae 3.7%). The Ephemeroptera, Trichoptera, and Plecoptera orders, known for their low tolerance to habitat perturbation, had high abundance in cropland and forested streams, whereas Diptera and Mollusca were more abundant in those impacted by cattle ranching. Results indicate that streams draining forests and croplands have better physical and biological conditions than those draining pastures, and highlight the need to implement protective measures to restore the latter. Rev. Biol. Trop. 62 (Suppl. 2): 203-219. Epub 2014 April 01.

Con el fin de determinar el impacto del uso del suelo sobre las características bióticas y abióticas de quebradas en la cuenca del río La Vieja, se evaluaron 21 quebradas en los municipios de Alcalá, Ulloa y Cartago (Valle del Cauca). Siete quebradas estaban protegidas por franjas de vegetación ribereña, ocho tenían influencia agrícola y seis influencia ganadera. Se registraron las condiciones de protección y perturbación del hábitat, aspectos físicos del cauce, se tomaron muestras de agua para análisis fisicoquímico y bacteriológico, y se recolectaron macroinvertebrados acuáticos. En las quebradas con influencia ganadera los sólidos disueltos, la alcalinidad, conductividad y fósforo total fueron significativamente mayores, mientras que el oxígeno disuelto fue significativamente menor. Las quebradas agrícolas y protegidas presentaron más sustratos gruesos y más tipos de corriente. Se recolectaron 26 777 macroinvertebrados de 17 órdenes, 72 familias y 95 géneros. Los grupos con mayor abundancia relativa fueron Diptera 62.8%, (Chironomidae 49.6%, Ceratopogonidae 6.7%), Mollusca 18.8% (Hydrobiidae 7.2%, Sphaeriidae 9.6%) y Trichoptera 5.7% (Hydropsychidae 3.7%). Ephemeroptera, Trichoptera y Plecoptera, presentaron mayor abundancia en las quebradas protegidas y con influencia agrícola, mientras los dípteros y moluscos fueron más abundantes en las ganaderas. Las quebradas protegidas y agrícolas presentan mejores condiciones físicas y biológicas que las quebradas con influencia ganadera.