Figure 4From: In situ studies of algal biomass in relation to physicochemical characteristics of the Salt Plains National Wildlife Refuge, Oklahoma, USAVariation in algal biomass as a function of (A) nitrogen, NH4+ and NO3- + NO2-, (B) orthophosphate, PO43- and ground water salt concentration per site. Error bars denote SE of means. (Chl-a: n = 108; NH4+, NO3- + NO2-, PO43- and salinity: n = 34–36)Back to article page