Abstract
Abstract. An improved understanding of present-day climate variability and change relies on high-quality data sets from the past 2 millennia. Global efforts to model regional climate modes are in the process of being validated against, and integrated with, records of past vegetation change. For South America, however, the full potential of vegetation records for evaluating and improving climate models has hitherto not been sufficiently acknowledged due to an absence of information on the spatial and temporal coverage of study sites. This paper therefore serves as a guide to high-quality pollen records that capture environmental variability during the last 2 millennia. We identify 60 vegetation (pollen) records from across South America which satisfy geochronological requirements set out for climate modelling, and we discuss their sensitivity to the spatial signature of climate modes throughout the continent. Diverse patterns of vegetation response to climate change are observed, with more similar patterns of change in the lowlands and varying intensity and direction of responses in the highlands. Pollen records display local-scale responses to climate modes; thus, it is necessary to understand how vegetation–climate interactions might diverge under variable settings. We provide a qualitative translation from pollen metrics to climate variables. Additionally, pollen is an excellent indicator of human impact through time. We discuss evidence for human land use in pollen records and provide an overview considered useful for archaeological hypothesis testing and important in distinguishing natural from anthropogenically driven vegetation change. We stress the need for the palynological community to be more familiar with climate variability patterns to correctly attribute the potential causes of observed vegetation dynamics. This manuscript forms part of the wider LOng-Term multi-proxy climate REconstructions and Dynamics in South America – 2k initiative that provides the ideal framework for the integration of the various palaeoclimatic subdisciplines and palaeo-science, thereby jump-starting and fostering multidisciplinary research into environmental change on centennial and millennial timescales.
Highlights
Simulating the complexity of Earth’s climate system is still a major challenge for even the most advanced Earth system models
Earliest Mauritia establishment was observed around 2 ka, but humans might have been present since the midHolocene leaving their signature on the present-day landscape
Many South America (SA) records have been excluded because their long time span (> 10 ka) coupled with a relatively slow sedimentation allows only low temporal resolution of sampling; slow sedimentation rates mean that many records do not have radiocarbon ages from within the last 2 kyr
Summary
Simulating the complexity of Earth’s climate system is still a major challenge for even the most advanced Earth system models. Studies have demonstrated the integration of multiple proxies (Li et al, 2010) in climate reconstructions, with a special focus on the last 2 millennia. This period could be considered a baseline to current conditions, as climate has been very similar to the present. To integrate records from different sedimentary archives across SA, a standard chronological framework is required To this end an alternative recalibrated age model and evaluation of chronologies have been undertaken to facilitate the integration of multi-proxy records in SA (Flantua et al, 2016). The lack of an adequate overview of available pollen records from the continent has been an impediment to the advancement of its use and inclusion in climate studies
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
