Exploring Silica Stoichiometry on a Large Floodplain Riverscape

Carey, Joanna C.; Jankowski, Kathi Jo; Julian, Paul; Sethna, Lienne R.; Thomas, Patrick K.; Rohweder, Jason J.

doi:10.3389/fevo.2019.00346

Cited by 11 publications

(17 citation statements)

References 84 publications

(118 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, we found that although the biomass of phytoplankton varied substantially in space and time across the large and dynamic river basin of the UMRS, warmer winters consistently supported greater phytoplankton biomass throughout the river, indicating that riverine phytoplankton will be sensitive to shifts in winter air temperatures. We hypothesized that the presence of ice cover during the winter would reverse the longitudinal pattern and decrease the lotic‐lentic differences in CHL typically observed during summer (Carey et al., 2019; Crawford et al., 2016; Houser, 2016; Houser et al., 2010), expectations which we largely confirmed. However, we also expected that there would be similar CHL temporal dynamics among areas in ice covered versus ice free reaches (i.e., north versus south), but found that inter‐annual CHL dynamics were independent among all reaches and between lotic and lentic areas.…”

Section: Discussionsupporting

confidence: 71%

“…Midwinter CHL was expectedly low compared to other seasons in the UMRS (Burdis et al, 2020;Carey et al, 2019;Houser et al, 2010Houser et al, , 2015, but similar to winter CHL measured in other freshwater systems (Hampton et al, 2017;Twiss et al, 2014) and in the lower Mississippi River (9-12 μg/L; Ochs et al, 2013). On average, winter CHL ranged between 18% and 64% of summer CHL, with the higher ratios occurring in southern reaches and backwater lakes.…”

Section: Spatial Patterns In Winter Chlsupporting

confidence: 67%

“…A similar pattern occurred for snow depth; the Open River reach had minimal snow cover (<1 cm) and Pool 8 had the maximum long-term average of 5.87 cm. Similar to summer conditions in the UMRS (Carey et al, 2019;Houser et al, 2010), total N and P generally increased and DSi decreased downriver within the UMR. The highest average values of N and P and lowest values of DSi occurred in the IL River (Figure 3), however, which meets the UMR near St. Louis and flows into Pool 26.…”

Section: Physical-chemical Conditionsmentioning

confidence: 73%

“…As a result, the UMRS contains a gradient of lentic and lotic areas ranging from backwater lakes to the main river channel (Bouska et al., 2018) that cover a wide range in residence time and hydraulic connectivity to the mainstem river flow. These physical differences set up gradients in water velocity (Table 1), temperature (Jankowski et al., 2020), and nutrient concentrations (Carey et al., 2019; De Jager & Houser, 2012) that can influence wintertime biological productivity.…”

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Warmer Winters Increase the Biomass of Phytoplankton in a Large Floodplain River

et al. 2021

View full text Add to dashboard Cite

Winter comprises a substantial fraction of the year across large areas of the globe, but what happens in aquatic ecosystems during winter is not well understood. Recent large-scale observations of decreasing ice cover (Sharma et al., 2016(Sharma et al., , 2019, warming winter temperatures (USGCRP, 2017), and increased recognition of connections between winter dynamics and conditions in other seasons (Cline et al., 2020;Collins et al., 2019;Katz et al., 2015) indicate a need to better understand the fundamental controls on winter conditions and their effects on aquatic processes and communities . We have made recent progress in understanding winter dynamics in lake ecosystems (e.g., Hampton et al., 2017), but we know much less about the winter ecology of rivers even though they are experiencing the same widespread increases in winter temperatures and ice loss (

show abstract

Section: Discussionsupporting

confidence: 71%

Section: Spatial Patterns In Winter Chlsupporting

confidence: 67%

Section: Physical-chemical Conditionsmentioning

confidence: 73%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Warmer Winters Increase the Biomass of Phytoplankton in a Large Floodplain River

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The deviation between theorized nutrient limitation and observed algal composition is not unexpected as stoichiometric ratios are but one driver of the seasonal shifts in algal community composition (e.g., Stevenson 1997). Interestingly, in the upper Mississippi River system, stoichiometric ratios indicate Si-limitation relative to N and, at times, P while N is limited relative to P in both the mainstem of the river as well as its major tributaries (Carey et al 2019). The change from P-limiting conditions in the headwater streams of KDW and SDW to N-limitation in the larger Mississippi River subbasins might explain why cyanobacterial blooms are observed rarely in headwater, agricultural streams while becoming increasingly common on larger rivers such as the Ohio (ORSANCO 2016) and Maumee (McKay et al 2018) rivers.…”

Section: Seasonality Of Nutrient Limitation and Eutrophication Potentialmentioning

confidence: 99%

Silicon concentrations and stoichiometry in two agricultural watersheds: implications for management and downstream water quality

et al. 2022

Self Cite

View full text Add to dashboard Cite

Agriculture alters the biogeochemical cycling of nutrients such as nitrogen (N), phosphorus (P), and silicon (Si) which contributes to the stoichiometric imbalance among these nutrients in aquatic systems. Limitation of Si relative to N and P can facilitate the growth of non-siliceous, potentially harmful, algal taxa which has severe environmental and economic impacts. Planting winter cover crops can retain N and P on the landscape, yet their effect on Si concentrations and stoichiometry is unknown. We analyzed three years of biweekly concentrations and loads of dissolved N, P, and Si from subsurface tile drains and stream water in two agricultural watersheds in northern Indiana. Intra-annual patterns in Si concentrations and stoichiometry showed that cover crop vegetation growth did not reduce in-stream Si concentrations as expected, although, compared to fallow conditions, winter cover crops increased Si:N ratios to conditions more favorable for diatom growth. To assess the risk of non-siliceous algal growth, we calculated a stoichiometric index to quantify biomass growth facilitated by excess N and P relative to Si. Index values showed a divergence between predicted algal growth and what we observed in the streams, indicating other factors in uence algal community composition. The stoichiometric imbalance was more pronounced at high ows, suggesting increased risk of harmful blooms as environmental change increases the frequency and intensity of precipitation in the midwestern U.S. Our data include some of the rst measurements of Si within small agricultural watersheds and provide the groundwork for understanding the role of agriculture on Si export and stoichiometry.

show abstract

Decoupling of silica, nitrogen and phosphorus cycling in a meromictic subalpine lake (Lake Iseo, Italy)

et al. 2022

View full text Add to dashboard Cite

Silica (Si), nitrogen (N) and phosphorus (P) loads and stoichiometry are key factors controlling the trophic status of lakes and coastal seas. In the hydrographic network, lakes also act as biogeochemical reactors, controlling both nutrient retention and fluxes. This work aimed to examine the coupling of Si, N and P cycling, together with their stoichiometry in a deep meromictic subalpine lake (Lake Iseo, Northern Italy). Si, N and P mass budgets were calculated by quantifying loads in the inlets and in the outlet over a period of 30 months (May 2016−October 2018), in-lake sedimentation rates and net nutrients accumulation in the water body. Lake Iseo acts as a biogeochemical filter, which differentially retains the external Si, N and P loads. Retention of Si and P was similar (75–79%), but considerably higher than N (45%), evidencing a decoupling of their fate due to in-lake processes. This differential retention is likely to be exacerbated by meromixis which enhances Si and P accumulation in the monimolimnion, while impairing denitrification, thus limiting N removal. Such decoupling resulted in an increase of the N:Si and N:P ratios in both the epilimnion and in the outlet compared to the inlets, whereas the ratios decreased in the monimolimnion. As a result, there may be a stronger Si and P limitation of the photic zone, leading to a shift towards more oligotrophic conditions. This transient equilibrium could be impaired in the case of water overturn produced by extreme climate events—a highly relevant issue, considering that a growing number of deep lakes are turning from holo-oligomictic to meromictic as a result of combined eutrophication and climate change.

show abstract

Exploring Silica Stoichiometry on a Large Floodplain Riverscape

Cited by 11 publications

References 84 publications

Warmer Winters Increase the Biomass of Phytoplankton in a Large Floodplain River

Warmer Winters Increase the Biomass of Phytoplankton in a Large Floodplain River

Silicon concentrations and stoichiometry in two agricultural watersheds: implications for management and downstream water quality

Decoupling of silica, nitrogen and phosphorus cycling in a meromictic subalpine lake (Lake Iseo, Italy)

Contact Info

Product

Resources

About