Global change revealed by palaeolimnological records from remote lakes: a review

Abstract

Over recent decades, palaeolimnological records from remote sites have provided convincing evidence for the onset and development of several facets of global environmental change. Remote lakes, defined here as those occurring in high latitude or high altitude regions, have the advantage of not being overprinted by local anthropogenic processes. As such, many of these sites record broad-scale environmental changes, frequently driven by regime shifts in the Earth system. Here, we review a selection of studies from North America and Europe and discuss their broader implications. The history of investigation has evolved synchronously with the scope and awareness of environmental problems. An initial focus on acid deposition switched to metal and other types of pollutants, then climate change and eventually to atmospheric deposition-fertilising effects. However, none of these topics is independent of the other, and all of them affect ecosystem function and biodiversity in profound ways. Currently, remote lake palaeolimnology is developing unique datasets for each region investigated that benchmark current trends with A celebration of Prof. Rick Battarbee's contributions to palaeolimnology, edited by Holmes et al.This paper has been written as a contribution to celebrating Rick Battarbee's influence on palaeolimnology. Some of us have benefitted from his leadership (and friendship) in transnational European projects during the last decade (e.g., ALPE, ALPE2, MOLAR, CHILL-10000, EMERGE, EUROLIMPACS), which together with some other initiatives spawned pan-European remote lake research. Others have respected Rick as a teacher, colleague and a friend. To some extent, this review follows the chronological order of topics addressed in these projects, which also respond to the growing social awareness about each issue. Rick also facilitated bridges between North American and European schools, and beyond. We expect his attitude towards collaboration will pervade and persist through the palaeolimnological community for years to come, and global change will certainly provide stimulating and challenging questions with which to do so.

Spatial variations in snowpack chemistry, isotopic composition of NO<sub>3</sub><sup>−</sup> and nitrogen deposition from the ice sheet margin to the coast of western Greenland

“…Holtgrieve et al (2011) asserted that δ( 15 N) records in lake sediments indicate a "coherent signal of anthropogenic nitrogen deposition to remote watersheds", yet a central problem remains as to why some remote lakes record a 20th century 15 N depletion signal, attributed to atmospheric inputs of anthropogenically produced NO − 3 , while others (often neighbouring sites) do not. This is an important issue as δ( 15 N) in lake sediments offers one of the few means of identifying a nitrogen effect on remote lakes over historic timescales and is central to the debate over the relative roles of climate change and nitrogen deposition in driving ecological change in remote lakes (Catalan et al, 2013;Wolfe et al, 2013). Stable isotope data are even more restricted than precipitation chemistry in the Arctic despite their value for understanding pollutant pathways and ecological impacts, with most published data derived from studies in the centre of the Greenland ice sheet (Hastings et al, 2009; or from Svalbard (Heaton et al, 2004;Tye and Heaton, 2007;Björkman et al, 2014).…”

Guide to diatoms in mountain lakes in the Retezat Mountains, South Carpathians, Romania

“…Th e study of diatoms is uneven, the pristine, arctic and mountain regions have been paid more attention only in the last couple of years (e.g. Catalan et al 2013). Studia bot.…”

The response of Cladocerans to recent environmental forcing in an Alpine Lake on the SE Tibetan Plateau

“…Evidence from palaeolimnological studies suggests that pronounced and unprecedented limnological and ecological changes have occurred over the past few centuries in many high altitude lakes (Battarbee et al, 2002;Catalan et al, 2013). Unlike lowland lakes, where the cultural impact of humans is unambiguous, remote alpine lakes are affected largely by climatic forcing such as temperature increases, variability in precipitation and snow cover (Battarbee et al, 2009) and more subtle effects of atmospheric pollution.…”