细胞配额解析中营养水库藻类生长的资源限制与营养阈值OA

Mesotrophic lakes and reservoirs,as critical sources of drinking water,exhibit unclear mechanisms governing the occur-rence of occasional algal blooms and the dynamics of nutrient limitation.This study investigated Duihekou Reservoir in Zhejiang Province through four years of in situ monitoring to elucidate fluctuations in algal growth rates and their dynamic coupling with intra-cellular nutrient quotas.Results indicated that during the diatom-dominated phase(December-April,DIA),the in situ algal growth rate varied markedly from-1.10 d-1 to 2.76 d-1,whereas during the cyanobacteria-dominated phase(July-August,CYA),it ranged from-0.43 d-1 to 0.81 d-1—higher than values typically observed in eutrophic systems—suggesting a high po-tential for rapid algal proliferation in mesotrophic waters.Growth rates in the DIA phase were primarily governed by nitrogen cell quotas,which may be attributed to the suppression of chlorophyll synthesis and nitrogen assimilation efficiency under light and tem-perature limitations.Therefore,a springtime rise in temperature and light intensity,coupled with elevated cellular nitrogen con-tent,could trigger diatom blooms.In contrast,growth rates in the CYA phase were co-regulated by phosphorus cell quotas and en-vironmental phosphorus quotas.Maintaining total phosphorus below 22 μg/L(95％CI:15-32 μg/L)could effectively suppress cyanobacterial blooms(chlorophyll-a＞10 μg/L).This study innovatively incorporates dynamic intracellular nutrient quotas to ana-lyze algal growth mechanisms,overcoming the traditional reliance on ambient nutrient concentrations,algal biomass,or N∶P ratios to determine nutrient limitation.The approach offers a new theoretical basis for water quality management and bloom forecasting in mesotrophic lakes and reservoirs.