Direct and Indirect Effects of Penguin Feces on Microbiomes in Antarctic Ornithogenic Soils

Abstract

Expansion of penguin activity in maritime Antarctica, under ice thaw, increases the chances of penguin feces affecting soil microbiomes. The detail of such effects begins to be revealed. By comparing soil geochemistry and microbiome composition inside (one site) and outside (three sites) of the rookery, we found significant effects of penguin feces on both. First, penguin feces change soil geochemistry, causing increased moisture content (MC) of ornithogenic soils and nutrients C, N, P, and Si in the rookery compared to non-rookery sites, but not pH. Second, penguin feces directly affect microbiome composition in the rookery, not those outside. Specifically, we found 4,364 operational taxonomical units (OTUs) in 404 genera in six main phyla: Proteobacteria, Actinobacteria, Gemmatimonadetes, Acidobacteria, Chloroflexi, and Bacteroidetes. Although the diversity is similar among the four sites, the composition is different. For example, penguin rookery has a lower abundance of Acidobacteria, Chloroflexi, and Nitrospirae but a higher abundance of Bacteroidetes, Firmicutes, and Thermomicrobia. Strikingly, the family Clostridiaceae of Firmicutes of penguin-feces origin is most abundant in the rookery than non-rookery sites with two most abundant genera, Tissierella and Proteiniclasticum. Redundancy analysis showed all measured geochemical factors are significant in structuring microbiomes, with MC showing the highest correlation. We further extracted 21 subnetworks of microbes which contain 4,318 of the 4,364 OTUs using network analysis and are closely correlated with all geochemical factors except pH. Our finding f penguin feces, directly and indirectly, affects soil microbiome suggests an important role of penguins in soil geochemistry and microbiome structure of maritime Antarctica.

Faunal input at host plants: Can camel thorn trees use nutrients imported by resident sociable weavers?

“…The hydrophobicity of these soils could benefit to the deep-rooted camel thorn trees in that competition from subcanopy vegetation is excluded. Furthermore, continuous deposition of feces by the weavers can lead to a change in soil microbial communities as has been previously shown to happen with penguin activity in maritime Antarctica (Guo et al, 2018). As such, changes in microbial communities can also potentially affect the establishment of plants (Hartman & Tringe, 2019;Raaijmakers, Paulitz, Steinberg, Alabouvette, & Moënne-Loccoz, 2009) and lead to the observed barren areas directly beneath the nests (Guyonnet et al, 2017;Pochana & Keller, 1999).…”

WITOD: A Tool for Within-Taxon Operational Taxonomic Unit Diversity Analysis

“…It will be useful in revealing the genetic polymorphism in general and aiding identifying the causative human pathogens or environmental disease vectors. WITOD is available at https://github.com/johncava/WITOD Background In microbiome research, current analysis of 16S rRNA gene amplicons is generally focused on the abundance of operational taxonomical units (OTUs) and the taxa which they belong to (e.g., Guo et al 2018). However, the biodiversity within taxa has been rarely studied, although it is important to both general microbiome compositional structure dissection and accurate diagnosis of human pathogens (Faith et al 2015).…”

Impact of penguin biotransport on the floral landscape of the South Sandwich Islands

“…The link between penguins and geochemical altercations of local soil was first expressed in Liguang et al (2004), who used a sulfur, phosphorous, calcium, copper, zinc, selenium, strontium, barium, and fluorine chemical array to infer historical penguin density. Like Guo et al (2018), the researchers demonstrated that nitrogen and phosphorus were strongly correlated with penguin droppings. However, toxification of the soil can occur in particularly dense colonies, precluding floral growth through both trampling and metal prevalence.…”