EPSAG FoLL-Project

Soil Algae: How Is Their Biodiversity Influenced by Different Land Use and Vegetation? Research in the Hainich-Dün Biological Diversity Exploratorium

What Is Our Plan?

Our FoLL project is integrated into an ongoing DFG research project. The students work in a team within the department, especially with doctoral student Yağmur Tarhana Çakır and technical assistant Birgit Olberg. A few samples will suffice to work on the most important objectives of the research project using various methods, thus reaching significant conclusions. The aim of the research project is a comprehensive assessment of the biodiversity of algae and cyanobacteria at species level and genotypic resolution in the upper soil layers (surface soils, 0-5 cm) and associated habitats, i.e., deadwood and tree bark. We investigate changes in the biodiversity of soil algae under different land uses, both in forests and grasslands. The goal is to identify the factors that determine the biodiversity of soil algae.

Our Vision for Project Implementation:

The FoLL team will conduct a pilot excursion to selected research plots in Hainich, both in the forest and in grasslands. The research plots to be sampled represent different forms and intensities of land use. After sample collection, the samples will be processed in the laboratory using DNA methods. The obtained DNA sequences (DNA metabarcoding) will be analyzed bioinformatically, resulting in a so-called taxon table. The results will then be discussed in relation to our working hypotheses:

  • The genetic diversity of soil algae and cyanobacteria is shaped by different vegetation, land use, and intensities of land use
  • The algal biodiversity in surface soils is closely linked to that of algal communities on deadwood and tree bark
  • Grasslands generally have a greater diversity of soil algae and cyanobacteria than forest soils
  • Mechanical disturbances and fertilization have a negative impact on the phototrophic diversity of soil surfaces

The Methods We Aim to Implement

  • Collecting samples from surface soils (0 – 5 cm) in forest and grassland areas (VIPs) as well as from the surfaces of wood substrates in forest areas, i.e., tree bark and deadwood
  • DNA extraction from the samples and amplicon-based metabarcoding using the molecular markers 23S UPA (chloroplast-encoded) with the Illumina MiSeq platform (2×300 bp, paired-end) for eukaryotic algal lineages and cyanobacteria, as well as ITS2 (nuclear-encoded) for green algae.
  • Isolating some cultures of terrestrial algae from the samples. Microscopy and DNA analyses on the obtained cultures.

Project Background:

Algae (photoautotrophic protists) and cyanobacteria are essential components of microbial communities in soils. They account for about 6% of the global net primary production of terrestrial vegetation. Due to their photosynthetic way of life, soil algae and cyanobacteria provide energy, carbon, and oxygen to the soil. In addition, they have numerous other beneficial effects on their habitats in the soil, such as an increase in fertility, improvement of the hydrological regime in the soil, and a stimulating effect on other microbial activities. As pioneers in soil colonization, they counteract soil erosion. They are an important food resource for small animals in the soil. However, the importance of the biodiversity of soil algae and cyanobacteria for complex processes in the soil has been underestimated so far, apparently due to insufficient knowledge of their biodiversity. The determinants of their biodiversity in real landscapes are not yet understood. For example, it is unclear how much land use and vegetation influence the genetic biodiversity of photoautotrophic microbial communities.