Are pollen records from small sites appropriate for REVEALS model-based quantitative reconstructions of past regional vegetation? An empirical test in southern Sweden

Abstract

In this paper we test the performance of the Regional Estimates of VEgetation Abundance from Large Sites (REVEALS) model using pollen records from multiple small sites. We use Holocene pollen records from large and small sites in southern Sweden to identify what is/are the most significant variable(s) affecting the REVEALS-based reconstructions, i.e. type of site (lakes and/or bogs), number of sites, site size, site location in relation to vegetation zones, and/or distance between small sites and large sites. To achieve this objective we grouped the small sites according to (i) the two major modern vegetation zones of the study region, and (ii) the distance between the small sites and large lakes, i.e. small sites within 50, 100, 150, or 200 km of the large lakes. The REVEALS-based reconstructions were performed using 24 pollen taxa. Redundancy analysis was performed on the results from all REVEALS-model runs using the groups within (i) and (ii) separately, and on the results from all runs using the groups within (ii) together. The explanatory power and significance of the variables were identified using forward selection and Monte Carlo permutation tests. The results show that (a) although the REVEALS model was designed for pollen data from large lakes, it also performs well with pollen data from multiple small sites in reconstructing the percentage cover of groups of plant taxa (e.g. open land taxa, summer-green trees, evergreen trees) or individual plant taxa; however, in the case of this study area, the reconstruction of the percentage cover of Calluna vulgaris, Cyperaceae, and Betula may be problematic when using small bogs; (b) standard errors of multiple small-site REVEALS estimates will generally be larger than those obtained using pollen records from large lakes, and they will decrease with increasing size of pollen counts and increasing number of small sites; (c) small lakes are better to use than small bogs if the total number of small sites is low; and (d) the size of small sites and the distance between them do not play a major role, but the distance between the small sites and landscape/vegetation boundaries is a determinant factor for the accuracy of the vegetation reconstructions.

Constraining the Deforestation History of Europe: Evaluation of Historical Land Use Scenarios with Pollen-Based Land Cover Reconstructions

“…The caveats of the REVEALS model and its application are discussed in detail in recent literature [40,46,61,82]. Here, we summarize the REVEALS uncertainties that are particularly relevant for this study.…”

Relative pollen productivity estimates for major plant taxa of cultural landscapes in central eastern China

“…The relatively high number of RPP estimates available in Europe made it possible to test and use the models developed for quantitative reconstruction of vegetation cover such as the Landscape Reconstruction Algorithm (LRA: REVEAL and LOVE models) (Sugita 2007a, b) and the Multiple Scenario Approach (MSA; Bunting and Middleton 2005). REVEALS reconstructions over the Holocene are now available for a large part of Europe (Nielsen and Odgaard 2010;Fyfe et al 2013;Trondman 2015;Trondman et al 2016;Marquer et al 2014). LOVE reconstructions were performed in southern Sweden (Cui et al 2014;Mazier et al 2015), Denmark (Overballe-Petersen et al 2013) and Britain (Fyfe et al 2013).…”

Quantified moorland vegetation and assessment of the role of burning over the past five millennia

“…() and Trondman et al. () have demonstrated it is possible to use a network of smaller sites to calculate the regional vegetation abundance. Count data from each site were aggregated into 500‐year contiguous time windows to facilitate correlation and comparison between sites.…”

“…Developments in understanding the pollen–vegetation relationship have resulted in improved approaches to the quantification of vegetation cov es and resulted in the Landscape Reconstruction Algorithm (LRA; Sugita, ,b). Much effort has gone into the parameterization of this new approach (Broström et al., ; Mazier et al., ), and it is now possible to estimate the relative abundance of key taxa around pollen sites separate from the ‘background’ vegetation (Cui et al., ; Hjelle et al, ; Trondman et al., ). Where networks of pollen sites exist, it is possible to generate spatially explicit, quantified past vegetation abundances using pollen count data.…”