Soils associated to different tree communities do not elicit predictable responses in lake bacterial community...

Area of Science:

• Environmental microbiology
• Aquatic ecology
• Terrestrial ecology

Background:

• Freshwater bacterioplankton are influenced by terrestrial inputs.
• Limited research exists on how different terrestrial sources impact aquatic bacterial communities.

Purpose of the Study:

• To investigate if soils from various tree species compositions differentially affect lake bacterial communities.
• To compare the taxonomic and metabolic responses of lake bacteria to soil amendments.

Main Methods:

• Lake water was incubated with five different soil types for six days.
• Bacterial taxonomic composition was analyzed using 16S rRNA gene sequencing.
• Bacterial metabolic activity was assessed using Biolog Ecoplates.

Main Results:

• Soil bacterial communities varied with tree species, but these differences were not reflected in the lake communities.
• Abundant bacterial taxa in the lake incubations were common to both lake water and soils (e.g., Cytophagales, Burkholderiales, Rhizobiales).
• Soil amendments increased substrate utilization by 60% compared to unamended controls, but no distinct metabolic profiles emerged based on soil source.

Conclusions:

• Terrestrial inputs stimulate ubiquitous bacterial taxa found across the terrestrial-aquatic continuum.
• Distinct forest soil types did not lead to predictable shifts in lake bacterioplankton structure.
• The study emphasizes the role of common microbial taxa in linking terrestrial and freshwater ecosystems.