Human impact and ecological changes in lakeshore environments. The contribution of non-pollen palynomorphs in Lake Banyoles (NE Iberia)

Abstract

The analysis of non-pollen palynomorphs (NPP) provides useful information about local environmental conditions. The study of a core from Lake Banyoles (Girona, NE Iberia) enabled the reconstruction of ecological changes and assessment of human impact in a lakeshore environment during the Mid-Holocene. This work aims to fill the gap in knowledge about the ecological significance of NPP in lowland areas in NE Iberia, and provides descriptions and illustrations of new types documented.Deforestation induced by Early Neolithic communities caused the proliferation of lignicolous fungi in decaying wood and an increase in soil erosion. The input of allochthonous mud led to higher turbidity in the lake water, causing a succession in aquatic organisms, from cyanobacteria to green algae. In that context, a group of erosion-associated fungal spore types were recorded. Indicators of soil disturbance and coprophilous fungi were recorded from 5000 to 4200cal BP, linked with local habitation during the Late Neolithic–Chalcolithic. The NPP analysis reflects the significant human impact that caused changing local environmental conditions, consistent with the signals based on pollen analysis.