If Watersheds Spoke: A condition analysis of the Rio Tomebamba watershed in southern Ecuador using GIS analysis

Understanding processes and ecological threats occurring at the watershed level scale composes a critical piece of water resource conservation and management. This proves doubly true in areas such as the Ecuadorian highlands where water resources depend heavily on the hydrologic regulation capacities of páramo soils. This study examined watershed condition of the Rio Tomebamba watershed and existing habitat for Metallura baroni and Chibchanomys orcesi, two highly endemic species, within its boundaries. Watershed condition was determined based on a simple index that considered nine indicators of watershed health—converted land, impacted riparian zones, impermeable surfaces, water quality, fluvial habitat condition, riparian vegetation condition, macroinvertebrate community composition, road density, and erosion potential—in four analysis regions of the Rio Tomebamba watershed. Data spanning a five-year period (2015-2019) were analyzed using ArcGIS Pro software. Cultivated pasture was the most common converted land type across all analysis regions, composing 5.8% of the entire Rio Tomebamba watershed. In general watershed condition was highest in the Llaviucu analysis region and lowest in the Lower Tomebamba analysis region. No analysis region, including the Llaviucu region which is protected almost entirely by the Cajas National Park boundary, received an “excellent” condition rating. The Rio Tomebamba watershed as a whole was determined to be in “acceptable” condition. The results showed that riparian corridor degradation posed the most concern across all analysis regions within the watershed. Conservation and restoration of such areas would provide critical habitat for Chibchanomys orcesi, a highly endemic water mouse, and serve as an effective long-term management strategy for the area’s water resources. El conocimiento de los procesos y amenazas ocurriendo al nivel de la cuenca es bastante importante para la gestión y conservación de los recursos de agua, especialmente en las regiones altas de Ecuador donde estos recursos dependen de la regulación hídrica de los suelos de páramo. Esta investigación consideró la condición de la cuenca de Rio Tomebamba y el hábitat que existe para Metallura baroni y Chibchanomys orcesi, dos especies endémicas, dentro de la cuenca. La condición de la cuenca se determinó por un índice simple, considerando nueve indicadores de la de una cuenca: tierra reconvertida, zonas de riberas impactadas, superficies impermeables, la calidad de agua, la condición de hábitat fluvial, la condición de vegetación ribereña, la composición de las comunidades de macroinvertebrados, la densidad de los caminos, y la potencia de erosión hídrica. Estos indicadores y el hábitat de las dos especies endémicas se analizaron sobre cuatro regiones dentro de la cuenca de Rio Tomebamba, usando ArcGIS Pro. Pasto cultivado fue el tipo de tierra reconvertida más común en todas las cuatro regiones y compuso 5.8% de la cuenca total. En general, la condición de la cuenca fue más alta en la región de Llaviucu y más baja en la región de Lower Tomebamba que en el resto de la cuenca. Ninguna de las regiones recibió una nota de condición excelente . La cuenca de Rio Tomebamba se determinó en condición aceptable. Los resultados demostraron que los corredores ribereños están en peor condición de los indicadores sobre todas las regiones de la cuenca. La conservación y restauración de estas áreas proveería hábitat importante para Chibchanomys orcesi, un ratón endémico de agua, y podría servir como una estrategia de gestión efectiva para los recursos de agua del área

Vegetation structure and aboveground biomass of Páramo peatlands along a high-elevation gradient in the northern Ecuadorian Andes

The high-elevation peatlands of the páramos of the northern Andes constitute a diverse environment that harbors large numbers of species and several types of plant communities along altitudinal, latitudinal, and environmental gradients. However, little is known about the structure and functioning of these ecosystems, including peatland vegetation types and their relative contribution to the production and accumulation of peat soils. In this paper we characterized the structure of peatland plant communities of the humid páramos of northern Ecuador by describing the distribution of plant growth-forms and their aboveground biomass patterns. Along an elevation gradient of 640 m we sampled vegetation in 16 peatlands and aboveground biomass in four peatlands. Three distinct peatland vegetation types were identified: High elevation Cushion peatlands, dominated by Plantago rigida and Distichia muscoides, Sedge and rush peatlands dominated by Carex spp. and Juncus spp., and Herbaceous and shrubby peatlands, with a more heterogenous and structurally complex vegetation. In terms of aboveground biomass, we found an 8-fold reduction in the higher peatlands compared to the lower sites, suggesting that the steep elevational gradients characteristic of Andean environments might be crucial in structuring the physiognomy and composition of peatland vegetation, either through its effects on temperature and other environmental factors, or through its effects on the age and development of soils. Additional studies are needed to evaluate the potential effects of temperature, hydrology, micro-topography, geological setting, and land-use, which are likely to influence vegetation patters in these peatlands

Drivers of Dust-Enhanced Snowpack Melt-Out and Streamflow Timing

The presence of dust on the snowpack accelerates snowmelt. This has been observed through snowpack and hydrometeorological measurements at a small study watershed in southwestern Colorado. For a 13-year period, we quantified the annual dust-enhanced energy absorption (DEAE) and used this information to model the snowpack melt-out under observed (with dust present) and clean conditions (no dust). We determine the difference in snow cover duration between actual (dust present) and simulated ideal (clean) snowpack (ΔSAG) to characterize the shifts in melt timing for each year. We compute the center of mass of runoff (tQ50) as a characteristic of snowmelt. DEAE, ΔSAG and tQ50 vary from year to year, and are dictated by the quantity of snow accumulation, and to a lesser extent the number of dust events, the annual dust loading, and springtime snowfall

Drivers of Dust-Enhanced Snowpack Melt-Out and Streamflow Timing

The presence of dust on the snowpack accelerates snowmelt. This has been observed through snowpack and hydrometeorological measurements at a small study watershed in southwestern Colorado. For a 13-year period, we quantified the annual dust-enhanced energy absorption (DEAE) and used this information to model the snowpack melt-out under observed (with dust present) and clean conditions (no dust). We determine the difference in snow cover duration between actual (dust present) and simulated ideal (clean) snowpack (ΔSAG) to characterize the shifts in melt timing for each year. We compute the center of mass of runoff (tQ50) as a characteristic of snowmelt. DEAE, ΔSAG and tQ50 vary from year to year, and are dictated by the quantity of snow accumulation, and to a lesser extent the number of dust events, the annual dust loading, and springtime snowfall