Ecological Indicators (Oct 2024)
Modern pollen–plant diversity relationships for reliable pollen-based reconstruction of past plant taxonomic and functional diversity: A case study in southwest Shandong, China
Abstract
Pollen diversity provides insights into our understanding of past plant diversity, a wide variety of diversity indices have been used to characterize plant diversity from sedimentary pollen. However, studies reported inconsistent associations between pollen-plant taxonomic diversity, this could be partly accounted for by biases due to interspecies differences in pollen production, pollen diffusion/deposition, and poorly specified dispersal distance of pollen-source plants. It is therefore crucial to improve the interpretation of the sedimentary pollen diversity by systematic studies of palynological and floristic diversity associations in contemporary landscapes.To test the reliability of pollen assemblages as a proxy of plant diversity, we collected pollen and vegetation from 36 surface sites in southwest Shandong. We detected the correlation between pollen-plant taxonomic and functional diversity indices from different spatial scales.Our results show pollen-plant correlations vary in spatial scales for different indices, the Spearman correlation analysis indicates significant and the strongest correlations between pollen-plant Shannon index around the RSAP (0.399 < ρ < 0.520), while the Pielou’s evenness shows significant and the highest correlations (0.411 < ρ < 0.425) around and beyond the RSAP, but only weak positive relationships can be detected between pollen-plant richness. Functional composition based on whole plant height and specific leave area and functional dispersion based on combined traits of whole plant height, specific leave area, seed mass, and leave dry mass shows significant positive pollen-plant associations, indicating that functional diversity may improve the pollen-plant link.Our results confirm that pollen data performs well in presenting plant taxonomic and functional diversity, which provides a solid theoretical basis for quantitative reconstruction of the long-term plant diversity dynamics and response of ecosystem functions to the environment in the future. Furthermore, the results demonstrate that the spatial scale of vegetation survey plays an important role in the representation of pollen diversity.
