Physiological characteristics of inorganic nitrogen uptake by spatially separate algal communities in a nitrogendeficient lake

摘要: SUMMARY 1. The physiological characteristics of nitrogen uptake by sublittoral and eulittoral (splash zone) epilithic periphyton as well epipelic in N-deficient Castle Lake, California were determined evaluating the half-saturation constants (Kt) initial slopes (Vmax/Kt) kinetics curves. These results compared to similar studies phytoplankton this lake. 2. strategies differed among various communities largely proximity each pools available dissolved inorganic N (DIN). 3. algae did not have a high biological affinity for either NH4 or NO3 depended on fixation their supply. community showed an increased capacity DIN at low substrate concentration, but measured community. Epipelic live immediately adjacent large pool interstitial sediment no adaptations surviving environment. 4. Kt values all benthic approximately two orders magnitude greater than ambient levels. In contrast, NH4+ very situ levels these nutrients.