Contribution of littoral and pelagic algal photosynthesis in Boreal Plain lakes (Alberta)

Contribution of the littoral to whole-lake algal photosynthesis was studied in four lakes on the Boreal Plain in Alberta, Canada. In the littoral zone, rates of phytoplankton and epiphyton photosynthesis were positively related to algal biomass and total dissolved phosphorus concentration (r_s 0.43–0.82, P < 0.001). Relationships between macrophyte surface area and biomass were species-specific and could not be grouped based on dissected or entire leaf morphology. Lake-specific relationships between macrophyte surface area and biomass suggest that the amount of surface area available for epiphyton colonization is lake specific. Data collected from the study lakes and literature values from seven others were used to develop a relationship between littoral surface area and contribution to whole-lake alga photosynthesis (r2 = 0.90, P < 0.0001). Knowledge of the contribution of littoral and pelagic algal photosynthesis will aid in refining models that focus on landscape-water quality interactions in relatively flat and nutrient-rich environments, such as the Boreal Plain.