Phytoplankton primary production of three temporary northern prairie wetlands

Abstract

Measurements of phytoplankton primary production in three temporary Alberta ponds indicate a huge potential carbon and energy source for higher trophic levels associated with these systems. The ponds had high levels of NO,-N (rnaximum 1.6 m g -~-' ) and PO,-P (maximum 3.6 m g .~-' ) . Water temperature varied by as much as 15°C over the diel cycle, while primary production peaked in mid-afternoon. Production rates ranged from 0.6 to 400 mg ~. r n -~-h -' and were strongly correlated ( r = 0.9) with phytoplankton density. Total annual production for the ponds varied from 187 to 331 1 kg C. These annual production values are low relative to prairie lakes; however, the number of small temporary ponds is about three orders of magnitude greater than lakes making phytoplankton production of these small water bodies a potentially important source of energy in prairie food webs.RCsnmC : Les mesures de Ia production primaire de phytoplancton dans trois 6tangs temporaires situCs en Alberta rCv8lent I'existence d9une importante source potentielle de carbone et d7Cnergie pour les niveaux trophiques supirieurs lies B ces syst5mes. Les Ctawgs prCsentaient des niveaux 6levCs de NO3-N (maximum, 1,6 r n g~-' ) et de PO4-P (maximum, 3,6 mg-L-'). La temptrature de l'eau a variC jusquV8 IP°C, pendant le cycle nycthCmCral, et la production primaire a plafonnC en milieu d7apr8s-midi. Les taux de production ont oscillC de 0,6 2 400 mg ~-m -~. h -' et Ctaient fortement corrClCs (r = 8,9) B la densite du phytoplancton. La production annuelle totale des Ctangs a variC de 187 B 3 31 1 kg @. Ces valeurs sasnt faibles quand on les compare a celles des lacs des prairies; toutefois, Be nsmbre de petits Ctangs temporaires est d'environ trois fois plus ClevC que le nornbre de lacs, en sorte que la production de phytoplancton de ces petites Ctendues d7eau constitue une source potentiellement importante d9Cnergie dans le rCseau alimentdre des prairies.[Traduit par la Rkdaction]

Sources and composition of sediment pore‐water dissolved organic matter in prairie pothole lakes

“…Alternatively, storm events and high precipitation over the same time frame could cause lake levels to rise and subsequently cause flow of lower DOC surface water into the benthic zone, resulting in the dilution of pore-water DOC. Primary productivity in surface waters is high in June, and from June to September sediment pore waters receive a flux of DOM from decomposing microbial detritus (Robarts et al 1995). Further increases in biomass during the growing season from plants in the littoral zone, as well as inputs from terrestrial plants, would also increase pore-water DOC concentrations.…”

Effect of nitrogen and phosphorus additions on a benthic microbial mat from a hypersaline lake

“…Furthermore, increasing shading by the overlying phytoplankton does not appear as a main factor of interference with growth of benthic phototrophic microorganisms (Marks & Lowe 1993, Sundback et al 1996 due to their rapid light acclimation (Falkowsky & LaRoche 1991), at least within the photic zone. Moreover, in contrast with the higher phytoplankton growth in shallow freshwater systems associated with increased nutrient availability, saline lakes sometimes respond to an increase in nutrient loading by decreasing phytoplankton biomass (Robarts et al 1995, Diaz et al 1998. In any case, our experimental design was adapted to study the influence of nutrient additions on microbial mat composition and functioning, while neglecting interactions between planktonic and benthic organisms, which is especially valid for the shallow littoral zone where microbial mats mostly developed.…”

The importance of phytoplankton production for carbon budgets in a semiarid floodplain wetland

“…Although some of the previously studied wetlands have high nutrient contents (e.g. Alberta ponds, Robarts & al., 1995), climatic conditions such as long freezing or their temporary character could result in environmental constraints of production ( Table 5). As compared with data gathered from lakes (Álvarez-Cobelas & Rojo, 1994), the values of PP in Tablas de Daimiel National Park are somewhat high, but within the range recorded for many lakes, being also substantially lower than those observed by Talling & al.…”

“…Matching this, nutrients did not appear to control net PP (Table 2). Nutrients have often been shown to poorly explain PP in wetlands (Robarts & al., 1995). In these systems, PP seems to be affected by interlinked abiotic and biotic processes, such as sediment metabolism and its interaction with plankton dynamics (Ortega-Mayagoitia & al., 2002Waiser & Robarts, 2004).…”

“…Few studies (Robarts & al., 1995;Robinson & al., 1997) have focused on shallow, clear-water wetlands, but studies in highly turbid wetlands, where high amounts of dissolved organic matter and/or particulate suspended matter can influence irradiance attenuation, and consequently PP, are almost lacking. This is unfortunate because phytoplankton can play a major role in the carbon metabolism of some wetlands (Robinson & al., 1997;, thereby influencing nutrient cycling.…”