Northernmost distribution of the andean bear (Tremarctos ornatus) in South America, and fragmentation of its associated andean forest and paramo ecosystems

Current northernmost distribution of the Andean bear (Tremarctos ornatus) is not defined precisely; mentioned to be located “at the Serranía del Perijá” without accurate/confirmed distribution records, and placed by the IUCN at the Serranía de Portuguesa (Venezuela). There is an information gap on the fragmentation of the Andean bear associated ecosystems (Andean forest and Paramo) throughout its distribution in Colombia and Venezuela. The aim of this study is to provide precise knowledge on the current northernmost distribution of the Andean bear in South America at the Serranía del Perijá, besides quantifying spatial trends of the fragmentation of its associated ecosystems at the eastern and western slopes. Confirmed distribution records were obtained from field surveys (2009 to 2016), literature, scientific collections and biodiversity databases. The fragmentation degree of Andean bear associated ecosystems was characterized using FRAGSTATS (V 4.2) software with satellite images from 2008. A current population block with at least three sectors of incidence is present along both slopes of the Serranía del Perijá. Although the Colombian slope comprises greater raw area of Andean bear associated ecosystems, it is highly fragmented and isolated. Core area analysis (extracting a disturbance buffer of 1,000 m into the border of each patch) exhibits a Venezuelan slope maintaining greater amount of Andean bear associated ecosystems at few, large and less fragmented patches. This study extends the distribution of the species 180 km until the north of the Serranía del Perijá (regarding the current distribution recognized by the IUCN) and provides the northernmost confirmed distribution records for South America: Barrancas (Colombia) and Mara (Venezuela) municipalities. This study provides the first fine-scale information on Andean bear associated ecosystems fragmentation for Colombia and Venezuela, with traceable landscape measurements permitting future long-term comparative analyses. A high fragmentation degree of the Andean bear associated ecosystems is present at the Colombian slope of the Serranía del Perijá due to extensive legal and illegal agricultural activities and wood extraction. The lack of information about the Andean bear distribution and its associated ecosystems fragmentation could be putting the survival of local populations at risk, while a clear knowledge on these issues could generate planned conservation actions by the governmental environmental authorities.La distribución más septentrional actual del oso andino (Tremarctos ornatus) no está definida con precisión; generalmente se le localiza “en la Serranía del Perijá” sin registros precisos/confirmados, y la UICN la ubica en la Serranía de Portuguesa (Venezuela). Existe un vacío de información de la fragmentación de los ecosistemas asociados al oso andino (bosque Andino y Páramo) en Colombia y Venezuela. El objetivo de este estudio es brindar conocimiento preciso sobre la distribución más septentrional del oso andino en Suramérica en la Serranía del Perijá, además de cuantificar las tendencias espaciales de la fragmentación de sus ecosistemas asociados en las vertientes occidental y oriental. Los registros de distribución confirmados se obtuvieron de exploraciones de campo (2009 to 2016), literatura, colecciones científicas y bases de datos de biodiversidad. El grado de fragmentación de los ecosistemas asociados al oso andino se caracterizó utilizando el software FRAGSTATS (V 4.2) con imágenes satelitales del 2008. Un bloque poblacional actual con al menos tres sectores de incidencia está presente en ambas laderas de la Serranía del Perijá. Si bien la vertiente colombiana presenta una mayor área en bruto de los ecosistemas asociados del oso andino, está altamente fragmentada y aislada. Análisis de área de nucleo (extrayendo un área de influencia de perturbación de 1,000 m desde el borde de cada parche) exhiben que la vertiente venezolana contiene una mayor cantidad de ecosistemas asociados al oso en pocos parches, grandes, y menos fragmentados. Este estudio extiende la distribución de la especie 180 km hasta el norte de la Serranía del Perijá (en relación con la distribución actual reconocida por la UICN) y proporciona los registros de distribución mas septentrionales confirmado para Sudamérica: municipio de Barrancas (Colombia) y Mara (Venezuela). Este estudio proporciona la primera información a escala fina sobre la fragmentación de los ecosistemas asocia- dos al oso andino para Colombia y Venezuela, con mediciones espaciales del paisaje monitoreables, permitiendo análisis comparativos a largo plazo. Un alto grado de fragmentación de los ecosistemas asociados al oso andino está presente en la vertiente colombiana de la Serranía del Perijá debido a actividades agrícolas legales e ilegales y extracción de madera. La falta de información sobre la distribución del oso andino y la fragmentación de sus ecosistemas asociados podría poner en riesgo la supervivencia de las poblaciones locales, mientras que un conocimiento claro sobre estos temas podría generar acciones de conservación planificadas por parte de las autoridades ambientales gubernamentalesFil: Rodríguez, Daniel. Fundación Wii; ColombiaFil: Shisley, Adriana Reyes. Fundación Wii; ColombiaFil: Reyes Amaya, Nicolás Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Gallegos Sánchez, Silvana. Universidad Central de Ecuador; EcuadorFil: Gutierrez, Jorge. Fundación Wii; ColombiaFil: Suárez, Raúl. Corporación Autónoma Regional del Cesar; ColombiaFil: Prieto, Fernando. Corporación Autónoma Regional de la Guajira; Colombi

Effect of riparian vegetation cover and season on aquatic macroinvertebrate assemblages in the Ecuadorian Andes

The purpose of this study was to investigate the effects of season and changes in the riparian vegetation cover on diversity, structure, temporal variability, and trophic structure of aquatic macroinvertebrate assemblage in the Sambache River, Pasochoa Wildlife Refuge, Ecuador. Macroinvertebrate samples were collected using a Surber bottom sampler during the dry and rainy seasons from sections of the river dissecting three different riparian vegetation types with varying degrees of disturbance: 1) Humid montane forest, 2) Secondary forest near maturity and 3) Disturbed forest with shrubs and pastures. A select set of environmental variables were collected from the same sites. Results show that the Sambache River macroinvertebrate fauna is mainly composed of aquatic insect represented by three orders: Diptera, Ephemeroptera and Trichoptera. Important differences in abundance of several genera were found between the three riparian vegetation types and seasons. Andesiops and Atopsyche were more abundant in the dry season in sections of the river from humid montane forest sites. Probezzia increased its abundance during the rainy season in the three riparian vegetation types. Using a Canonical Correspondence Analysis to assess the effect of environmental variables on aquatic macroinvertebrate assemblages, I found that conductivity and amount of total dissolved solids were the most important parameters explaining macroinvertebrate assemblage structure. Regression analysis showed that genera richness and diversity were influenced by flow velocity, and that the most abundant genera in this study were controlled by a combination of different environmental variables. Trophic guilds were dominated by the collector-gatherers in all section of the river across the two seasons. Predators increased during the rainy season, possibly related to an increased abundance of food resources. This study provides further information on the distribution of macroinvertebrate taxa in the Ecuadorian Andes and their relationship with environmental factors. The study suggests that riparian vegetation may affect assemblage structure and that current land-use change in the region is affecting the composition of the aquatic fauna. I recommend that environmental variables and macroinvertebrates in the Sambache River should be monitored long term to establish better management strategies to protect the watershed and its ecosystem services.Norwegian University of Life Sciences and National Secretary of Higher Education, Sciences, Technology and Innovation of Ecuador (SENESCYT)2014-07-3

Repository file

Photo

Data from: Northernmost distribution of the Andean bear (Tremarctos ornatus) in South America, and fragmentation of its associated Andean forest and Paramo ecosystems

Current northernmost distribution of the Andean bear (Tremarctos ornatus) is not defined precisely; mentioned to be located “at the Serranía del Perijá” without accurate/confirmed distribution records, and placed by the IUCN at the Serranía de Portuguesa (Venezuela). There is an information gap on the fragmentation of the Andean bear associated ecosystems (Andean forest and Paramo) throughout its distribution in Colombia and Venezuela. The aim of this study is to provide precise knowledge on the current northernmost distribution of the Andean bear in South America at the Serranía del Perijá, besides quantifying spatial trends of the fragmentation of its associated ecosystems at the eastern and western slopes. Confirmed distribution records were obtained from field surveys (2009 to 2016), literature, scientific collections and biodiversity databases. The fragmentation degree of Andean bear associated ecosystems was characterized using FRAGSTATS (V 4.2) software with satellite images from 2008. A current population block with at least three sectors of incidence is present along both slopes of the Serranía del Perijá. Although the Colombian slope comprises greater raw area of Andean bear associated ecosystems, it is highly fragmented and isolated. Core area analysis (extracting a disturbance buffer of 1,000 m into the border of each patch) exhibits a Venezuelan slope maintaining greater amount of Andean bear associated ecosystems at few, large and less fragmented patches. This study extends the distribution of the species 180 km until the north of the Serranía del Perijá (regarding the current distribution recognized by the IUCN) and provides the northernmost confirmed distribution records for South America: Barrancas (Colombia) and Mara (Venezuela) municipalities. This study provides the first fine-scale information on Andean bear associated ecosystems fragmentation for Colombia and Venezuela, with traceable landscape measurements permitting future long-term comparative analyses. A high fragmentation degree of the Andean bear associated ecosystems is present at the Colombian slope of the Serranía del Perijá due to extensive legal and illegal agricultural activities and wood extraction. The lack of information about the Andean bear distribution and its associated ecosystems fragmentation could be putting the survival of local populations at risk, while a clear knowledge on these issues could generate planned conservation actions by the governmental environmental authorities