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Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/6178

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Sirvi Artiklid Autor "Adrian, Rita" järgi

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  • Pisipilt
    Kirje
    Effects of trophic status, water level, and temperature on shallow lake metabolism and metabolic balance: A standardized pan-European mesocosm experiment
    (Wiley, 2019) Scharfenberger, Ulrike; Jeppesen, Erik; Beklioğlu, Meryem; Søndergaard, Martin; Angeler, David G.; Çakıroğlu, Ayşe İdil; Drakare, Stina; Hejzlar, Josef; Mahdy, Aldoushy; Papastergiadou, Eva; Šorf, Michal; Stefanidis, Konstantinos; Tuvikene, Arvo; Zingel, Priit; Adrian, Rita; Centre for Limnology. Institute of Agricultural and Environmental Sciences
    Important drivers of gross primary production (GPP) and ecosystem respiration (ER) in lakes are temperature, nutrients, and light availability, which are predicted to be affected by climate change. Little is known about how these three factors jointly influence shallow lakes metabolism and metabolic status as net heterotrophic or autotrophic. We conducted a pan-European standardized mesocosm experiment covering a temperature gradi- ent from Sweden to Greece to test the differential temperature sensitivity of GPP and ER at two nutrient levels (mesotrophic or eutrophic) crossed with two water levels (1 m and 2 m) to simulate different light regimes. The findings from our experiment were compared with predictions made according the metabolic theory of ecology (MTE). GPP and ER were significantly higher in eutrophic mesocosms than in mesotrophic ones, and in shallow mesocosms compared to deep ones, while nutrient status and depth did not interact. The estimated temperature gains for ER of ~ 0.62 eV were comparable with those predicted by MTE. Temperature sensitivity for GPP was slightly higher than expected ~ 0.54 eV, but when corrected for daylight length, it was more consistent with predictions from MTE ~ 0.31 eV. The threshold temperature for the switch from autotrophy to heterotrophy was lower under mesotrophic (~ 11 C) than eutrophic conditions (~ 20 C). Therefore, despite a lack of signifi- cant temperature-treatment interactions in driving metabolism, the mesocosm’s nutrient level proved to be cru- cial for how much warming a system can tolerate before it switches from net autotrophy to net heterotrophy.
  • Pisipilt
    Kirje
    Storm impacts on phytoplankton community dynamics in lakes
    (Wiley, 2020) Stockwell, Jason D.; Doubek, Jonathan P.; Adrian, Rita; Anneville, Orlane; Carey, Cayelan C.; Carvalho, Laurence; De Senerpont Domis, Lisette N.; Dur, Gaël; Frassl, Marieke A.; Grossart, Hans-Peter; Ibelings, Bas W.; Lajeunesse, Marc J.; Lewandowska, Aleksandra M.; Llames, María E.; Matsuzaki, Shin-Ichiro S.; Nodine, Emily R.; Nõges, Peeter; Patil, Vijay P.; Pomati, Francesco; Rinke, Karsten; Rudstam, Lars G.; Rusak, James A.; Salmaso, Nico; Seltmann, Christian T.; Straile, Dietmar; Thackeray, Stephen J.; Thiery, Wim; Urrutia-Cordero, Pablo; Venail, Patrick; Verburg, Piet; Woolway, R. Iestyn; Zohary, Tamar; Andersen, Mikkel R.; Bhattacharya, Ruchi; Hejzlar, Josef; Janatian, Nasime; Kpodonu, Alfred T. N. K.; Williamson, Tanner J.; Wilson, Harriet L.; Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences
    In many regions across the globe, extreme weather events such as storms have increased in frequency, intensity, and duration due to climate change. Ecological theory predicts that such extreme events should have large impacts on ecosystem structure and function. High winds and precipitation associated with storms can affect lakes via short-term runoff events from watersheds and physical mixing of the water column. In addition, lakes connected to rivers and streams will also experience flushing due to high flow rates. Although we have a well-developed understanding of how wind and precipitation events can alter lake physical processes and some aspects of biogeochemical cycling, our mechanistic understanding of the emergent responses of phytoplankton communities is poor. Here we provide a comprehensive synthesis that identifies how storms interact with lake and watershed attributes and their antecedent conditions to generate changes in lake physical and chemical environments. Such changes can restructure phytoplankton communities and their dynamics, as well as result in altered ecological function (e.g., carbon, nutrient and energy cycling) in the short- and long-term. We summarize the current understanding of storm-induced phytoplankton dynamics, identify knowledge gaps with a systematic review of the literature, and suggest future research directions across a gradient of lake types and environmental conditions.