caa a22 4500 445891955 CHVBK 20180317145619.0 cr unu---uuuuu 170323e20110201xx s 000 0 eng 10.1007/s10750-010-0394-5 doi (NATIONALLICENCE)springer-10.1007/s10750-010-0394-5 Salmaso Nico IASMA Research and Innovation Centre, Fondazione E. Mach-Istituto Agrario di S. Michele all'Adige, Environment and Natural Resources Area, Via E. Mach, 38010, S. Michele all'Adige, Trento, Italy aut Interactions between nutrient availability and climatic fluctuations as determinants of the long-term phytoplankton community changes in Lake Garda, Northern Italy [Elektronische Daten] [Nico Salmaso] Major focus in interpreting phytoplankton changes in specific typologies of waterbodies or in single lakes is directed towards nutrients and climatic dynamics. During the last 35years, Lake Garda (Northern Italy; A=368km2, z max=350m, V=49km3) underwent a significant increase of phosphorus in the water column, from ca. 10μg P l−1 to 18-22μg P l−1. At the multi-decadal scale, the increase of the trophic status had a positive impact on the growth of Cyanobacteria (mainly Oscillatoriales) and, partly, diatoms, as demonstrated by the long-term ecological research carried out since the beginning of the 1990s in the deepest zone of the lake. Conversely, the increase of Peridiniales (mostly Ceratium hirundinella) in the recent years appeared also associated with the interannual variations of lake temperature. At the seasonal and annual scale, the development of the large diatoms and Oscillatoriales during the periods of their maximum growth (early spring, and summer and autumn, respectively) was strongly controlled by the extent of spring vertical water mixing and nutrient fertilization of surface waters, which, in turn, were negatively dependent on the air and water temperatures in winter and early spring. Therefore, contrary to the positive impact of milder winters on phytoplankton growth in many lakes of high latitudes, warmer winter temperatures in deep oligomictic lakes of lower latitudes can determine periodic shifts towards more oligotrophic conditions and a minor development of diatoms and specific harmful cyanobacterial groups (Oscillatoriales). The complex relationships between the explanatory and response variables were tested by applying Path Analysis (Structural Equation Modeling). This multiequational technique has great potential for studying causal relationships in temporally ordered variables. The results highlight the necessity to study the consequences of climatic fluctuations on the phytoplankton communities at different temporal scales and complexity, also including the indirect effects of climatic dynamics mediated by the morphometric, morphological and hydrological characteristics of lakes, and the possible synergic or opposite effects with other forcing variables, including nutrients. Springer Science+Business Media B.V., 2010 Large lakes nationallicence Phytoplankton nationallicence Eutrophication nationallicence Climatic fluctuations nationallicence Path analysis nationallicence Hydrobiologia Springer Netherlands 660/1(2011-02-01), 59-68 0018-8158 660:1<59 2011 660 10750 https://doi.org/10.1007/s10750-010-0394-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10750-010-0394-5 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Salmaso Nico IASMA Research and Innovation Centre, Fondazione E. Mach-Istituto Agrario di S. Michele all'Adige, Environment and Natural Resources Area, Via E. Mach, 38010, S. Michele all'Adige, Trento, Italy aut NATIONALLICENCE 773 0- Hydrobiologia Springer Netherlands 660/1(2011-02-01), 59-68 0018-8158 660:1<59 2011 660 10750 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer