Upscaling dynamic eco-evolutionary models from local communities to metacommunities and biogeographic scales

Material for workshop

Abstract

Two key question in the iDiv research area Biodiversity and Complexity are “which processes drive the emergence of biodiversity patterns across spatial scales from local communities over metacommunities to biomes”, and “how does evolutionary diversification influence the broad-scale assembly and composition of biomes”? One approach to tackle these questions is to use dynamic modelling. However, using the same model (e.g., an individual-based model) to describe biodiversity patterns from local to metacommunity and even larger spatial and/or evolutionary timescales is computationally impossible. This causes the problem of how to transfer essential information across spatial and temporal scales, from smaller to larger scales, a process generally known as upscaling.

We are a group of iDiv reserachers involved in a new flexpool project (Disentangling eco-evolutionary dynamics across temporal and spatial scales) that face multiple spatial and temporal upscaling problems. The workshop objectives are to (i) bring together iDiv researchers interested in upscaling, to (ii) provide an overview on different upscaling techniques, and to (iii) develop concrete ideas of how to accomplish upscaling with an eco-evolutionary (1) spatial perspective from individuals to communities, metacommunities and finally to biogeographic scales; and (2) a temporal perspective from a few generations, to mesoscale to macroevolutionary time.

We will propose a hierarchical and modular approach where the model at the more detailed scale will be used to parameterize a “meta-model” operating at the next scale that will be enriched in a subsequent step with processes becoming relevant at the larger scale.

Plan for the two workshop sessions

Upscaling is a rather technical modelling issue and for a fruitful discussion we need sufficient background information on different methods of upscaling. We therefore structured the workshop in two steps:

The first session will provide an overview on basic upscaling techniques and we present the three hierarchical scales we will treat:

· overview on upscaling in ecology (Thorsten)

· from the individual (neighbourhood) to the community scale (Thorsten)

· from the community to the metacommunity scale (Duarte)

· from the metacommunity to the global eco-evolutionary dynamics (Oskar)

During the second session we will discuss how we can coherently combine and harmonize the three models from the individual scale to the community scale to the metacommunity scale to scale of global eco-evolutionary dynamic. To do this we suggest as possible themes to discuss:

· how can we consider environmental heterogeneity (environmental stochasticity) across these scales?

· how can we harmonize the dispersal kernels across these three scales?

· how should we model evolution and speciation?

Overheads of the 4 talks

Talk 1) Thorsten Wiegand: overview on upscaling in ecology

Talk 2) Thorsten Wiegand: from the individual (neighbourhood) to the community scale

Talk 3) Duarte Viana: from the community to the metacommunity scale

Talk 4) Oskar Hagen: from the metacommunity to the global eco-evolutionary dynamics

Literature to upscaling

1) Reviews

Levin (1992) Ecology The classical paper on the problem of pattern and scale in ecology

Peters and Herrick (2004) Oikos A forum paper on strategies for spatial extrapolation of ecological models, for non-spatial, spatially implicit and spatially explicit models. Trade-offs in realism and potential errors for these classes of models are illustrated using a case study of the northern spotted owl.

Urban (2005) Ecology A review on modelling ecological processes across scales that provides a nice overview on different methods for scaling simulations developed at fine grain and small extent, to their implications over much larger extent. The intent in scaling is to simplify the model while retaining those details essential for larger-scale applications. This approach should lead to scaling rules that are well founded in fine-scale ecological process and yet useful for making predictions at the larger scales of management and environmental policy.

Wu and Li (2006) A book chapter in “Scaling and Uncertainty Analysis in Ecology.” Summary of upscaling methods, including similarity-based scaling methods (e.g., power laws and allometry) and dynamics model-based scaling methods.

Denny and Benneditti-Cecchi (2012) AREES They review the principles of mechanistic response functions to describe how phenomena interact across scales.

Fritsch et al. (2020) MEE A recent review that gives an overview of scaling approaches in ecological modelling. They classify scaling approaches into pre-model scaling, in-model scaling and post-model scaling depending on the timing of the scaling relative to the main modelling process.

2) Upscaling methods papers

Chesson (2008) Ecol Compl The paper presents scale transition theory to be used to explain the emergence of new properties on large scales from the interaction between nonlinearities and variation on small scales. It applies statistical theory for averaging nonlinear functions to understanding this interaction.

Seidl et al. (2012) Ecol Model An example for upscaling a process in a detailed simulation model using look up tables.

Strigul (2012) A book chapter that introduces a theoretical framework for the scaling of forest dynamics from individual to the landscape level based on the Perfect Plasticity Approximation (PPA), a mathematical upscaling procedure for individual-based forest dynamic models.

Cipriotti et al. (2016) MEE An example for non-parametric upscaling using look-up tables, Markov chains and additional larger-scale processes.

Rödig et al. (2016) GEB An individual-based forest model is used together with remote sensing and forest inventory data to estimate the variation of aboveground biomass across the Amazon rain forest.

Rammer and Seidl (2018) MEE An example for non-parametric upscaling, look up tables and deep neural networks.

Thompson et al. (2020) ELE The paper presents an approach to upscale from the community to the metacommunity scale based on Lotka-Volterra style models for each pixel and additional larger-scale processes.

Last update: 06.10.2020