Hydrogeomorphology explains acidification‐driven variation in aquatic biological communities in the Neversink Basin, USA

Abstract

Describing the distribution of aquatic habitats and the health of biological communities can be costly and time-consuming; therefore, simple, inexpensive methods to scale observations of aquatic biota to watersheds that lack data would be useful. In this study, we explored the potential of a simple "hydrogeomorphic" model to predict the effects of acid deposition on macroinvertebrate, fish, and diatom communities in 28 sub-watersheds of the 176-km2 Neversink River basin in the Catskill Mountains of New York State. The empirical model was originally developed to predict stream-water acid neutralizing capacity (ANC) using the watershed slope and drainage density. Because ANC is known to be strongly related to aquatic biological communities in the Neversink, we speculated that the model might correlate well with biotic indicators of ANC response. The hydrogeomorphic model was strongly correlated to several measures of macroinvertebrate and fish community richness and density, but less strongly correlated to diatom acid tolerance. The model was also strongly correlated to biological communities in 18 sub-watersheds independent of the model development, with the linear correlation capturing the strongly acidic nature of small upland watersheds (< 1 km2). Overall, we demonstrated the applicability of geospatial data sets and a simple hydrogeomorphic model for estimating aquatic biological communities in areas with stream-water acidification, allowing estimates where no direct field observations are available. Similar modeling approaches have the potential to complement or refine expensive and time-consuming measurements of aquatic biota populations and to aid in regional assessments of aquatic health.

Scale-dependent groundwater contributions influence patterns of winter baseflow stream chemistry in boreal catchments

“…Links between variable groundwater contributions and water chemistry across the Krycklan Catchment suggest important network heterogeneity in the vulnerability of streams to disturbance. In particular, there is ongoing concern regarding the pH sensitivity of surface waters in response to past atmospheric deposition and future land use activities (e.g., forestry) that remove base cations from surrounding soils [ Dunford et al ., ; Harpold et al ., ]. Acidity in streams of this region is driven largely by a combination of organic acids and acid neutralizing capacity [ Hruska et al ., ], with strong temporal variation linked to snowmelt hydrology which has implication for the distribution of acid‐sensitive biota [ Serrano et al ., ].…”

Influence of the Landscape Template on Chemical and Physical Habitat for Brown Trout Within a Boreal Stream Network

“…Both local chemical and physical habitat can be strongly influenced by the surrounding terrestrial landscape and catchment characteristics (Harpold et al, 2013). Stream physical habitat can be related to characteristics of the surrounding watershed (e.g., slope, soil type, landcover/land use) or in the near-stream zone (e.g., riparian vegetation, shading).…”