oa Composition of Organic Matter in Phytogenic Hillocks Occurring on Inland Dunes in Temperate Climate Zones

Phytogenic hillocks are aeolian landforms shaped by sand accumulation around plants, forming under favorable habitat conditions. While well-studied in arid regions, research in temperate zones is scarce. In these areas, hillocks often emerge on deforested sites, where wind erosion depletes soil horizons, triggering aeolian processes.

This study examined the Bledowska Desert in southern Poland, where hillocks, primarily forming around Salix arenaria, are widespread. Samples from five cross-sections represented different developmental stages. Most hillocks formed on exposed bedrock due to deflation, except for site I, which developed on fossil podzolic soil with a partially preserved illuvial horizon.

Soil analysis included total organic carbon (TOC) and gas chromatography-mass spectrometry (GC-MS). TOC content varied, grouping into organic-rich (>2%), organic-poor (<0.9%), and intermediate soils (0.9–2%).

Sugars were the most abundant compounds, with sucrose and trehalose dominating. Sucrose likely originates from cyanobacteria, while trehalose, arabitol, and mannitol suggest fungal or lichen sources.

Non-sugar compounds included n-alkanoic acids, n-alkanols, and short-chain fatty acids. Dicarboxylic acids, primarily adipic and pimelic, were linked to C3 plants. Dehydroabietic acid indicated coniferous input, while ß-sitosterol was the most abundant steroid, commonly found in higher plants.