Quality matters: Response of bacteria and ciliates to different allochthonous dissolved organic matter sources as a pulsed disturbance in shallow lakes

YALÇIN G., Yıldız D., Calderó-Pascual M., Yetim S., Şahin Y., Parakatselaki M., ...Daha Fazla

The Science of the total environment, cilt.916, ss.170140, 2024 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 916
  • Basım Tarihi: 2024
  • Doi Numarası: 10.1016/j.scitotenv.2024.170140
  • Dergi Adı: The Science of the total environment
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Analytical Abstracts, Aqualine, Aquatic Science & Fisheries Abstracts (ASFA), BIOSIS, Biotechnology Research Abstracts, CAB Abstracts, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, Environment Index, Food Science & Technology Abstracts, Geobase, Greenfile, Metadex, Pollution Abstracts, Veterinary Science Database, Civil Engineering Abstracts
  • Sayfa Sayıları: ss.170140
  • Anahtar Kelimeler: Bottom-up control, Brownification, Mesocosm experiment, Nutrients, Top-down control
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

Shallow lake ecosystems are particularly prone to disturbances such as pulsed dissolved organic matter (allochthonous-DOM; hereafter allo-DOM) loadings from catchments. However, the effects of allo-DOM with contrasting quality (in addition to quantity) on the planktonic communities of microbial loop are poorly understood. To determine the impact of different qualities of pulsed allo-DOM disturbance on the coupling between bacteria and ciliates, we conducted a mesocosm experiment with two different allo-DOM sources added to mesocosms in a single-pulse disturbance event: Alder tree leaf extract, a more labile (L) source and HuminFeed® (HF), a more recalcitrant source. Allo-DOM sources were used as separate treatments and in combination (HFL) relative to the control without allo-DOM additions (C). Our results indicate that the quality of allo-DOM was a major regulator of planktonic microbial community biomass and/or composition through which both bottom-up and top-down forces were involved. Bacteria biomass showed significant nonlinear responses in L and HFL with initial increases followed by decreases to pre-pulse conditions. Ciliate biomass was significantly higher in L compared to all other treatments. In terms of composition, bacterivore ciliate abundance was significantly higher in both L and HFL treatments, mainly driven by the bacterial biomass increase in the same treatments. GAMM models showed negative interaction between metazoan zooplankton biomass and ciliates, but only in the L treatment, indicating top-down control on ciliates. Ecosystem stability analyses revealed overperformance, high resilience and full recovery of bacteria in the HFL and L treatments, while ciliates showed significant shift in compositional stability in HFL and L with incomplete taxonomic recovery. Our study highlights the importance of allo-DOM quality shaping the response within the microbial loop not only through triggering different scenarios in biomass, but also the community composition, stability, and species interactions (top-down and bottom-up) in bacteria and plankton.