![Sample our Environment & Agriculture journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5934/TOC-Subject-Sample-2021-Environment-Agriculture.jpg"})
Abstract
Diatoms in surface sediment from 50 Canadian Precambrian Shield lakes in the Muskoka-Haliburton and central Ontario regions were analyzed in order to establish the relationship between lake trophic status and subfossil diatom assemblage structure. Distribution optima of the most abundant diatom taxa in 30 lakes were calculated by using a weighted average technique. The most commonly observed diatom taxa were classified into five trophic categories: O = oligotrophia OM = oligomesotrophic, M = mesotrophic, ME = mesoeutrophic and E = eutrophic. Abundance values of these diatom trophic groups were used to estimate corresponding values of total phosphorus (TP), chlorophyll-a (chl-a), Secchi depth (SD) and LTSI (a new lake trophic status index developed in this study) using multiple regression methods. The statistical equations obtained by both simple and multiple regression techniques were then applied to 20 newly sampled lakes to test the model. The transfer functions between diatom community structure and each of the trophic status variables, except chl-a, were significant (P < 0.001). We therefore concluded that diatoms ware useful indicators of lake trophic status, especially in situations where no other information is available, and in studies of the trophic history of lakes.