Nutrient limitation of periphyton growth in arctic lakes in south-west Greenland

Abstract

Many arctic lakes are oligotrophic systems where phototrophic growth is controlled by nutrient supply. Recent anthropogenic nutrient loading is associated with biological and/or physico-chemical change in several lakes across the arctic. Shifts in nutrient limitation (nitrogen (N), phosphorus (P), or N ? P) and associated effects on the growth and composition of algal communities are commonly reported. The Kangerlussuaq region of south-west Greenland forms a major lake district which is considered to receive little direct anthropogenic disturbance. However, long-range transport of pollutant N is now reaching Greenland, and it was hypothesised that a precipitation gradient from the inland ice sheet margin to the coast might also deliver increased N deposition. In situ nutrient bioassays were deployed in three lakes across the region: ice sheet margin, inland (close to Kangerlussuaq) and the coast (near Sisimiut), to determine nutrient limitation of lakes and investigate any effects of nutrients on periphyton growth and community composition. Nutrient limitation differed amongst lakes: N limitation (ice sheet margin), N and P limitation (inland) and N ? P co-limitation (coast). Factors including variation in N supply, ice phenology, seasonal algal succession, community structure and physical limnology are explored as mechanisms to explain differences amongst lakes. Nutrient limitation of arctic lakes and associated ecological impacts are highly variable, even across small geographic areas. In this highly sensitive region, future environmental change scenarios carry a strong risk of significantly altering nutrient limitation; in turn, potentially severely impacting lake structure and function.

Responses of benthic algae to nutrient enrichment in a shallow lake: Linking community production, biomass, and composition

“…Silicon is often limiting for diatoms, which compose the majority of Mývatn's epipelic communities (both in our experimental microcosms and in situ), and previous research has shown that silicon can become limiting to diatoms after N and P enrichment (Carrick & Lowe, ). While results from studies using nutrient‐diffusing agar have shown mixed results regarding benthic algal nutrient limitation (Fairchild & Lowe, ; Fairchild et al., ; Hogan, McGowan, & Anderson, ; Lepori & Robin, ; Maberly, King, Dent, Jones, & Gibson, ; Steinman et al., ), few of these have assessed the limitation of sediment‐associated epipelic communities. Meta‐analysis results suggest that producer communities associated with marine sediments or soft‐bottoms showed weaker responses to nutrient enrichment than benthic communities on hard substrates (Elser et al., ).…”

“…MLM coefficients are the main effects for N or P plus the interaction term for each algal group. The coefficients shown are the means obtained by parametric bootstrapping over 2,000 simulations Other Green Scenedesmus Coefficient: P Diatoms Green Algae (Fairchild & Lowe, 1984;Fairchild et al, 1985;Hogan, McGowan, & Anderson, 2014;Lepori & Robin, 2014;Maberly, King, Dent, Jones, & Gibson, 2002;Steinman et al, 2016), few of these have assessed the limitation of sediment-associated epipelic communities. Metaanalysis results suggest that producer communities associated with marine sediments or soft-bottoms showed weaker responses to nutrient enrichment than benthic communities on hard substrates (Elser et al, 2007).…”

Alder, Nitrogen, and Lake Ecology: Terrestrial-Aquatic Linkages in the Postglacial History of Lone Spruce Pond, Southwestern Alaska

“…In northern high latitude lakes, these stressors have an increased capacity for ecosystem disruption, as a) temperature changes are amplified in the Arctic [2, 8, 9] and b) despite their distance from industrial Nr sources, most boreal and arctic lakes are nutrient poor (oligotrophic) and their ecosystems are adapted to low nutrient levels, making them sensitive to even small changes in nutrient loading [10, 11]. Indeed, northern high latitude lake ecosystems have shown a dramatic response to climate warming in the last century [12, 13] and enhanced atmospheric Nr deposition has been shown to be occurring even in remote locations [14, 15] with attendant effects on ecosystems [6, 7, 16, 17].…”

Capturing temporal and spatial variability in the chemistry of shallow permafrost ponds

“…This suggests that influences such as runoff inputs, evapoconcentration, bathymetry, and internal processes (sediment-water interaction and biological cycling) may be driving these absolute differences while preserving seasonal trajectories relative to a pond mean value. Other authors have reported on local spatial heterogeneity of biogeochemical properties of ponds, such as the conditions of nutrient limitation of primary productivity in different lakes (Hogan et al, 2014;Symons et al, 2012). This work suggests that the seasonal trajectory of concentration of at least some chemical species are not reflective of this spatial variability and instead more reflective of landscape-level processes.…”