RELATIONSHIPS BETWEEN LAKE MORPHOMETRY, WATER QUALITY, AND AQUATIC MACROPHYTES, IN GREEK LAKES

摘要

In the current study, the relationships between lake morphological characteristics, water chemistry parameters and aquatic macrophyte data of nineteen lakes of Greece were investigated. Statistical and ordination analysis was performed in order to distinguish possible correlations be tween lake morphology features, key water quality para meters and hydrophyte distribution. Water quality and hy drophyte data for eleven out of nineteen lakes were ob tained from field surveys carried out the last five years. Water quality parameters, lake morphology and hydro phyte data published in scientific papers and reports were used as well. Several lake morphology parameters such as average depth, maximum depth, relative depth, surface area, lake catchment area, volume, Schindler's ratio and morphoedaphic index (MEI) were included in the statisti cal analysis. The statistical assessment of our data in cluded Pearson correlations between the lake morphology and water quality parameters, Principal component analy sis (PCA), in order to distinguish the key morphological parameters and Redundancy Analysis (RDA) in order to estimate possible associations between the hydrophyte dis tribution and the morphology of the lakes. The results re vealed several significant correlations between the phys icochemical and geomorphological variables. Most notable correlations include those between Schindler's ratio, Mor phoedaphic index, Secchi depth, conductivity and chloro phyll-a. The results of PCA indicated lake volume and altitude as key variables with the strongest influence on the lake discrimination, followed by Schindler's ratio and MEI. The RDA results revealed a possible association of several hydrophyte species in shallower lakes with greater values of MEI. However, the RDA results between aquatic macrophyte and physicochemical data did not reveal any pattern of macrophyte species distribution among the stud ied lakes. According to our results, Schindler's ratio and relative depth are the most important morphological pa rameters indicating the combined influence of catchment and lake morphometry on the water quality. The MEI was associated with key physicochemical parameters and there fore could provide an additional simple and efficient tool of classification of Greek lakes in the frame of establishing a new typology.