A general framework for quantifying the effects of land-use history on ecosystem dynamics

Abstract

Land-use legacies are important for explaining present-day ecological patterns and processes. However, an overarching approach to quantify land-use history effects on ecosystem properties is lacking, mainly due to the scarcity of high-quality, complete and detailed data on past land use. We propose a general framework for quantifying the effects of land-use history on ecosystem properties, which is applicable (i) to different ecological processes in various ecosystem types and across trophic levels; and (ii) when historical data are incomplete or of variable quality. The conceptual foundation of our framework is that past land use affects current (and future) ecosystem properties through altering the past values of resources and conditions that are the driving variables of ecosystem responses. We describe and illustrate how Markov chains can be applied to derive past time series of driving variables, and how these time series can be used to improve our understanding of presentday ecosystem properties. We present our framework in a stepwise manner, elucidating its general nature. We illustrate its application through a case study on the importance of past light levels for the contemporary understorey composition of temperate deciduous forest. We found that the understorey shows legacies of past forest management: high past light availability lead to a low proportion of typical forest species in the understorey. Our framework can be a useful tool for quantifying the effect of past land use on ecological patterns and processes and enhancing our understanding of ecosystem dynamics by including legacy effects which have often been ignored.

Tipping point dynamics in global land use

“…Second, we treat the combined land useeconomic system as a unit and study the characteristic transitions using a Hidden Markov model approach (Usher 1981, Depauw et al 2019, McClintock et al 2020. Markov chain models allow us to study the properties that result in a tipping point as an emergent phenomenon including path dependence at the pixel level (Geoghegan et al 1998) and the potential for lock-in, non-determinism, and nonunidirectional change.…”

Integrating regional and local monitoring data and assessment tools to evaluate habitat conditions and inform river restoration

“…However, this level of analysis was beyond the scope of our study. Understanding past land use in the region may help explain some of the variability observed among groups, considering that current land use may not reflect past land uses ( Depauw et al, 2019 , Steel et al, 2017 ). Across the region, further examination of the interaction between epilimnetic releases of warm water from low head dams, reach-scale groundwater-surface water exchange, contributions from cold tributaries, and the effects of water withdrawals is needed to understand how these factors may influence summer thermal conditions.…”

Evaluating structural and compositional canopy characteristics to predict the light‐demand signature of the forest understorey in mixed, semi‐natural temperate forests

“…Temperate forest herb layers are slow‐changing systems (Dornelas et al, 2013; Perring et al, 2018), and understorey communities can display a delayed response to overstorey canopy and light dynamics (Plue et al, 2013). Hence, the current understorey composition might be more strongly related to past light availability (and thus past management) than to the contemporary light conditions (Depauw et al, 2019a). Ash and Barkham (1976) studied understorey composition in coppiced woodlands and found that many perennials can persist throughout the entire coppice cycle.…”

“…Additionally, in vegetation resurvey studies, which provide a unique opportunity to estimate vegetation and environmental changes over the past decades (Kapfer et al, 2017), values of light availability at the forest floor in the past (e.g. at the time of the original survey) are typically not available, and light levels need to be estimated from stand or tree characteristics that were recorded (Depauw et al, 2019a).…”