The importance of allochthonous organic matter quality when investigating pulse disturbance events in freshwater lakes: a mesocosm experiment

2021-11-01
Caldero-Pascual, Maria
Yildiz, Dilvin
Yalçın, Gülce
Metin, Melisa
Yetim, Sinem
Fiorentin, Claudia
Andersen, Mikkel Rene
Jennings, Eleanor
Jeppesen, Erik
Ger, Kemal Ali
Beklioğlu, Meryem
McCarthy, Valerie
Extreme precipitation is occurring with greater frequency and intensity as a result of climate change. Such events boost the transport of allochthonous organic matter (allo-OM) to freshwater ecosystems, yet little is known about the impacts on dissolved organic matter (DOM) quality and seston elemental stoichiometry, especially for lakes in warm climates. A mesocosm experiment located in a Turkish freshwater lake was designed to simulate a pulse event leading to increased inputs of allo-OM by examining the individual effects of increasing water colour (HuminFeed (R), HF), the direct effects of the extra energetic inputs (alder tree leaf leachate, L), and the interactions of the single treatment effects (combination of both sources, HFL), along with a comparison with unmanipulated controls. Changes in the DOM quality and nutrient stoichiometry of the allo-OM treatment additions was examined over the course of the experiments. Results indicated that there was an increase of high recalcitrant DOM components in the HF treatment, in contrast to an increase in less aromatic microbially derived molecules for the L treatment. Unexpectedly, seston C:P ratios remained below a severe P-limiting threshold for plankton growth and showed the same temporal pattern in all mesocosms. In contrast, seston N:P ratios differed significantly between treatments, with the L treatment reducing P-limiting conditions, whilst the HF treatment increased them. The effects of the combined HFL treatment indicated an additive type of interaction and chlorophyll-a was highest in the HFL treatment. Our results demonstrate that accounting for the optical and stoichiometric properties of experimental allo-OM treatments is crucial to improve the capacity to explain extrapolated conclusions regarding the effects of climate driven flooding on freshwater ecosystems in response to global climate change.
HYDROBIOLOGIA

Suggestions

Identifying impacts of climate change on water resources using CMIP6 simulations: Havran basin case
Çaktu, Yasemin; Yücel, İsmail; Fıstıkoğlu, Okan; Department of Earth System Science (2022-9-2)
This study aims to investigate climate change effect on precipitation, temperature and discharge in Havran basin which has thousands of decares of agricultural lands. Changes in precipitation and temperature were determined using 10 global climate models (GCMs) for total precipitation and 13 GCMs for average temperature from Coupled Model Intercomparison Project Phase 6 (CMIP6) for the historical period, SSP2-4.5 (moderate-case) and SSP5-8.5 (worst-case) scenarios. Both station observations and ERA5-Land re...
Assessment of changes in climate indices of the mediterranean climate region of Turkey
Çetinkaya , İzem; Yücel, İsmail; Department of Civil Engineering (2020-10-28)
As a consequence of climate change, frequency and intensity changes in extreme weather events have occurred. One of the most vulnerable regions of the world that is affected by the climate change is the Mediterranean region. Turkey as a Mediterranean country has a great importance to investigate the changes in climate behavior. 57 stations from Mediterranean climate region of Turkey have been selected as the study area for this thesis. This study aims to assess the climate indices that carry the valua...
Assessing the impact of climate change on Mogan and Eymir Lakes' levels in Central Turkey
Yagbasan, Ozlem; Yazıcıgil, Hasan (2012-05-01)
Global warming is likely to have significant effect on the hydrological cycle. Some parts of the world may see significant reductions in precipitation or major alterations in the timing of wet and dry seasons. Climate change is one of the serious pressures facing water resources and their management over the next few years and decades. As part of the southern belt of Mediterranean Europe, Turkey is highly vulnerable to anticipated climate change impacts. The changes in global climate will seriously affect i...
The role of local governments in clima techange adaptation: achievements and barriers in the turkish case
Özdemir Eroğlu, Gülin.; Balaban, Osman; Department of Earth System Science (2019)
Global warming is manifesting visible consequences at regional and local scales. Cities are considered among major contributors of climate change while also being a victim of it. It is vital to anticipate the adverse impacts of climate change in cities and take appropriate actions to prevent or minimize the damage they may be exposed. The Mediterranean Basin, in which Turkey is located, is one of the regions with the highest vulnerability to climate change. Turkey’s First National Communication on Climate C...
The impact of climate change on a Mediterranean shallow lake: insights based on catchment and lake modelling
Coppens, Jan; Trolle, Dennis; Jeppesen, Erik; Beklioğlu, Meryem (Springer Science and Business Media LLC, 2020-05-19)
Shallow lakes in the semi-arid climate zone of the Mediterranean are sensitive to drought due to the low annual precipitation and high evaporation. Changes in precipitation and temperature as projected by climate change scenarios will have an effect on the hydrology of these shallow lakes with secondary effects on nutrient dynamics and ecological state. In this study, we used a combined modelling approach that included the catchment model Soil and Water Assessment Tool (SWAT) and the lake model PCLake to st...
Citation Formats
M. Caldero-Pascual et al., “The importance of allochthonous organic matter quality when investigating pulse disturbance events in freshwater lakes: a mesocosm experiment,” HYDROBIOLOGIA, pp. 0–0, 2021, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/94714.