S TUDYING POLLEN REPRESENTATION OF VEGETATION AND PLANT RICHNESS FROM P AMPEAN COASTAL DUNES (A RGENTINA , S OUTH A MERICA ) : EXPLORING FROM LOCAL TO LANDSCAPE QUANTITATIVE LINKAGES

Background and aims: Studying plant dynamics through past pollen records may contribute to a better understanding of long-term changes in plant communities. Thus, this study aims to establish whether surface pollen composition and richness of the Argentinean Coastal Dune System reflect landscape heterogeneity in coastal dune environments. M&M: Twenty-four sediment surface samples were collected in small lagoons. Landscape-scale heterogeneity up to 2000 m was mapped and classified in landscape units. Multivariate analyses were used to classify pollen samples and compare them to landscape unit coverage (%). Also, we evaluate plant species and pollen richness relationship by linear regression models. Results: The relationship between plant and pollen richness is influenced by taxonomic smoothing, pollen production and taphonomic constraints (dispersal and preservation). The pollen assemblages and pollen richness from surface sediments of small lagoons and interdune slacks reflect plant richness and vegetation heterogeneity at the landscape scale (ca. 1000-2000 m). The main contributors to pollen richness are anemophilous pollen types, although some entomophilous pollen types are useful to infer some local heterogeneity. Conclusions: We report the first quantitative analysis on pollen-vegetation relationship of coastal ecosystems showing that pollen records reflect landscape vegetation attributes, encouraging the study of past plant diversity and landscape variability based on pollen records.