How Environment and Plants Affect Chemical Changes in Lake Sediments

Jenn Hoskins
23rd July, 2024

How Environment and Plants Affect Chemical Changes in Lake Sediments

In the shore sediments of Lake Kinneret, the influence of Cordgrass (Cyperus articulatus) on redox chemistry was found to be secondary to the more dominant effects of sediment permeability and desiccation.

Image adapted from: Kamyshny et al. / CC BY (Source)

Key Findings

  • Researchers at Ben-Gurion University studied oxygen depletion during the decomposition of aquatic plants in Oleo Lagoon, Brazil
  • Different species of aquatic plants decompose at varying rates, affecting oxygen consumption differently
  • Most oxygen demand during decomposition is due to the breakdown of dissolved carbon from the plant detritus
Oxygen depletion in aquatic environments is a growing concern, especially in regions impacted by organic matter decomposition. A recent study by researchers at Ben-Gurion University[1] delved into the mechanisms driving oxygen consumption during the breakdown of aquatic plant detritus. This research builds on earlier studies that explored various aspects of organic matter decomposition and its environmental impact. The study aimed to understand how different species of aquatic plants contribute to oxygen depletion during decomposition. The researchers collected detritus from seven species of aquatic macrophytes from Oleo Lagoon in Brazil. These species included Cabomba furcata, Cyperus giganteus, Egeria najas, Eichhornia azurea, Salvinia auriculata, Oxycaryum cubense, and Utricularia breviscapa[2]. By examining the carbon content of leachates and dissolved oxygen concentrations during the decomposition process, they sought to identify the factors influencing oxygen consumption. The researchers conducted mineralization experiments using the closed bottles method. They incubated lake water with macrophyte detritus under aerobic conditions and in darkness for 45 to 80 days at 20 degrees Celsius. The study found that decomposition rates varied significantly among the different macrophytes. This variation was primarily attributed to the molecular and elemental composition of the detritus. In the short term, most of the oxygen demand was linked to the demineralization of the dissolved carbon fraction[2]. These findings align with previous research on the role of organic carbon in oxygen consumption. For instance, a study on the Gulf of Aqaba highlighted the importance of organic carbon in sedimentary environments. The Gulf's sediments, which are poor in organic carbon, show limited microbial sulfate reduction due to the presence of reactive iron minerals from desert dust deposition[3]. This contrasts with the macrophyte detritus in the current study, where organic carbon plays a significant role in oxygen depletion. The study also draws parallels with research on Lake Matano in Indonesia, where low sulfate levels and efficient scavenging of sulfide by iron minerals create a unique environment for microbial communities[4]. In both cases, the availability of specific elements and compounds influences the microbial processes that drive oxygen consumption and other biogeochemical cycles. By understanding the factors that control oxygen consumption during detritus decomposition, the study provides valuable insights into managing aquatic ecosystems. It highlights the need to consider the specific characteristics of organic matter when assessing its environmental impact. This research not only advances our knowledge of aquatic biogeochemistry but also offers practical implications for preserving water quality in affected regions.

EnvironmentBiochemEcology

References

Main Study

1) Influence of environmental settings, including vegetation, on speciation of the redox-sensitive elements in the sediments of monomictic Lake Kinneret

Published 22nd July, 2024

https://doi.org/10.1007/s10201-024-00756-7

Related Studies

2) Oxygen demand during mineralization of aquatic macrophytes from an oxbow lake.

Journal: Brazilian journal of biology = Revista brasleira de biologia, Issue: Vol 68, Issue 1, Feb 2008

3) Impact of Aeolian Dry Deposition of Reactive Iron Minerals on Sulfur Cycling in Sediments of the Gulf of Aqaba.

https://doi.org/10.3389/fmicb.2017.01131

4) Photoferrotrophs thrive in an Archean Ocean analogue.

https://doi.org/10.1073/pnas.0805313105


Related Articles

An unhandled error has occurred. Reload 🗙