Using ancient sedimentary DNA to forecast ecosystem trajectories under climate change

Abstract

Ecosystem response to climate change is complex. In order to forecast ecosystem dynamics, we need high-quality data on changes in past species abundance that can inform process-based models. Sedimentary ancient DNA ( sed aDNA) has revolutionised our ability to document past ecosystems' dynamics. It provides time series of increased taxonomic resolution compared to microfossils (pollen, spores), and can often give species-level information, especially for past vascular plant and mammal abundances. Time series are much richer in information than contemporary spatial distribution information, which have been traditionally used to train models for predicting biodiversity and ecosystem responses to climate change. Here, we outline the potential contribution of sed aDNA to forecast ecosystem changes. We showcase how species-level time series may allow quantification of the effect of biotic interactions in ecosystem dynamics, and be used to estimate dispersal rates when a dense network of sites is available. By combining palaeo-time series, process-based models, and inverse modelling, we can recover the biotic and abiotic processes underlying ecosystem dynamics, which are traditionally very challenging to characterise. Dynamic models informed by sed aDNA can further be used to extrapolate beyond current dynamics and provide robust forecasts of ecosystem responses to future climate change. This article is part of the theme issue ‘Ecological novelty and planetary stewardship: biodiversity dynamics in a transforming biosphere’.

Navigating ecological novelty towards planetary stewardship: challenges and opportunities in biodiversity dynamics in a transforming biosphere

“…This complexity calls for increasingly sophisticated methods and additional data to understand and forecast the nature and consequences of global change, a call that is being met with rapid advances in technology, data availability and modelling approaches, along with the recognition that a combination of data, multiple methods and approaches yields the strongest inference [ 61 ]. For instance, in this theme issue, Alsos et al [ 62 ] outlines the potential contribution of ancient sedimentary DNA (sedaDNA) to improve our ability to forecast the composition and functioning of emerging novel ecosystems by identifying the patterns and mechanisms involved in biodiversity and ecosystem responses to past climate change. The authors highlight how sedaDNA analyses can provide valuable insights into the processes that drive ecosystem dynamics under changing environmental conditions by identifying the patterns and mechanisms associated with biodiversity and ecosystem responses to past climate change.…”

“…Including regeneration processes in models -Luu et al [53] Indicators of invasion impact -Henriksen et al [63] Ancient DNA assemblage reconstruction -Alsos et al [62] Species Assemblage Ecosystem Humans Focus Modelling range change -Zurrell et al [36] Understanding and managing novel communities -McGeoch et al [17] Macroecology to study resilience -Enquist et al [23] Soil-climate interactions constrain species distributions -Ni & Vellend [37] Past climate effects on current biodiversity -Fastovich et al [29] Functioning and stewardship of emerging novel ecosystems Integrating people into understanding, forecasting, and management of the dynamics of novel ecosystems management responses to the dynamics driven by human-induced climate change [40], which will also require new thinking relative to conventional conservation paradigms, notably adapting to inevitable change and facilitating dynamics towards net positive biodiversity outcomes. In both cases, our understanding of current and future communities can be advanced by considering the six fundamental processes identified for community biology: dispersal, drift, abiotic interactions, within-guild interactions, crossguild interactions and genetic changes [42,43].…”