Lake Kinneret long-term data of the epilimnetic concentrations (ppm) and loads (tones) of the total Nitrogen (TN), total Phosphorus (TP), total inorganic Nitrogen (TIN), total Dissolved Phosphorus (TDP), Phytoplankton...Lake Kinneret long-term data of the epilimnetic concentrations (ppm) and loads (tones) of the total Nitrogen (TN), total Phosphorus (TP), total inorganic Nitrogen (TIN), total Dissolved Phosphorus (TDP), Phytoplankton groups’ biomass, water level (WL) and Jordan River Discharge were analyzed. Previously collected data compiled aimed at an insight into the causative background for the modification of Phytoplankton community change. The study was carried out by searching for relations between algal groups’ densities and nutrient conditions in the Epilimnion by the use of statistical methods (Simple and Fractional Polynomial Regressions). The study is aimed at analyzing the relations between algal biomass and nutrient contents. It was found that Nitrogen decline and slight increase of phosphorus were followed by Peridinium (Photo 1)?decline and biomass increase of non-peridinium algae. It is suggested that nitrogen supply for algal growth is mostly from external sources, and the reduction of nitrogen in the epilimnion was caused by external removal. Contrary to nitrogen, phosphorus sourcing is only partly external (dust deposition, drainage basin) and mostly internal through double channels: Microbial mineralization of bottom sediments and Peridinium cysts mediation. The resulted complexity of the Kinneret ecosystem structure is nitrogen limitation, and enhancement of Non-peridinium algal growth, mostly Cyanobacteria.展开更多
During 1970-2001, several ecological changes were documented in the Lake Kinneret Ecosystem: Decline of total Nitrogen (TN) and increase of total Phosphorus (TP) loads with a corresponding decline of TN/TP ratio. The ...During 1970-2001, several ecological changes were documented in the Lake Kinneret Ecosystem: Decline of total Nitrogen (TN) and increase of total Phosphorus (TP) loads with a corresponding decline of TN/TP ratio. The phytoplankton assemblages indicated consequence Increase of Cyanobacteria accompanied by elevation of the biomass of Chlorophyta and Diatoms. The Kinneret ecosystem functioning represented two superimposed events: the decline of TN enhanced Cyanobacteria and elevation of TP that was reflected by an increase of Chloropytes and Diatoms. Removal of Nitrogen was achieved but P load remained high enough to enhance Chlorophyta and Diatoms. Consequently, a top priority of future management perspective should be reduction of Phosphorus inputs.展开更多
文摘Lake Kinneret long-term data of the epilimnetic concentrations (ppm) and loads (tones) of the total Nitrogen (TN), total Phosphorus (TP), total inorganic Nitrogen (TIN), total Dissolved Phosphorus (TDP), Phytoplankton groups’ biomass, water level (WL) and Jordan River Discharge were analyzed. Previously collected data compiled aimed at an insight into the causative background for the modification of Phytoplankton community change. The study was carried out by searching for relations between algal groups’ densities and nutrient conditions in the Epilimnion by the use of statistical methods (Simple and Fractional Polynomial Regressions). The study is aimed at analyzing the relations between algal biomass and nutrient contents. It was found that Nitrogen decline and slight increase of phosphorus were followed by Peridinium (Photo 1)?decline and biomass increase of non-peridinium algae. It is suggested that nitrogen supply for algal growth is mostly from external sources, and the reduction of nitrogen in the epilimnion was caused by external removal. Contrary to nitrogen, phosphorus sourcing is only partly external (dust deposition, drainage basin) and mostly internal through double channels: Microbial mineralization of bottom sediments and Peridinium cysts mediation. The resulted complexity of the Kinneret ecosystem structure is nitrogen limitation, and enhancement of Non-peridinium algal growth, mostly Cyanobacteria.
文摘During 1970-2001, several ecological changes were documented in the Lake Kinneret Ecosystem: Decline of total Nitrogen (TN) and increase of total Phosphorus (TP) loads with a corresponding decline of TN/TP ratio. The phytoplankton assemblages indicated consequence Increase of Cyanobacteria accompanied by elevation of the biomass of Chlorophyta and Diatoms. The Kinneret ecosystem functioning represented two superimposed events: the decline of TN enhanced Cyanobacteria and elevation of TP that was reflected by an increase of Chloropytes and Diatoms. Removal of Nitrogen was achieved but P load remained high enough to enhance Chlorophyta and Diatoms. Consequently, a top priority of future management perspective should be reduction of Phosphorus inputs.
