Effect of historical land‐use and climate change on tree‐climate relationships in the upper Midwestern United States

Abstract

Contemporary forest inventory data are widely used to understand environmental controls on tree species distributions and to construct models to project forest responses to climate change, but the stability and representativeness of contemporary tree-climate relationships are poorly understood. We show that tree-climate relationships for 15 tree genera in the upper Midwestern US have significantly altered over the last two centuries due to historical land-use and climate change. Realised niches have shifted towards higher minimum temperatures and higher rainfall. A new attribution method implicates both historical climate change and land-use in these shifts, with the relative importance varying among genera and climate variables. Most climate/land-use interactions are compounding, in which historical land-use reinforces shifts in species-climate relationships toward wetter distributions, or confounding, in which land-use complicates shifts towards warmer distributions. Compounding interactions imply that contemporary-based models of species distributions may underestimate species resilience to climate change.

How will climate novelty influence ecological forecasts? Using the Quaternary to assess future reliability

“…Although using a more recent reference baseline reduces the calculated level of future climate novelty somewhat, it overlooks the fact that many species distributions may contain strong memory and legacy effects and may be better matched to the climates of the 20th century (or earlier) than to those of the more recent decades. This is especially true for long‐lived sessile organisms such as trees: their distributions are likely to be in increasing disequilibrium with climate and so average climate during the last few decades may not reliably characterize true climatic requirements (Goring & Williams, ; Svenning & Sandel, ). A more recent climatic baseline may be more appropriate for organisms that (1) are better suited to rapidly tracking their climatic niche and (2) have good observational data for recent decades.…”

“…their distributions are likely to be in increasing disequilibrium with climate and so average climate during the last few decades may not reliably characterize true climatic requirements (Goring & Williams, 2017;Svenning & Sandel, 2013). A more recent climatic baseline may be more appropriate for organisms that (1) are better suited to rapidly tracking their climatic niche and (2) have good observational data for recent decades.…”

Refining predictions of population decline at species' rear edges

“…Anthropogenic land‐use during the last few hundred years has altered the realized niche of species and consequently their contemporary distribution is often not in equilibrium with the range of ecological conditions they are able to exploit. For example, using “pre‐settlement” vegetation estimations inferred from survey records (1830–1910), and historical climate and contemporary data, Goring and Williams () demonstrated that human land conversion shifted the past distribution of some tree genera in Midwestern United States, from drier and warmer climates in the past to wetter and cooler conditions today. Land‐use changes and associated habitat modifications, therefore, complicate the identification of “ecological edges” of a species' distribution (Figure ).…”

Scale sensitivity of the relationship between alpha and gamma diversity along an alpine elevation gradient in central Nepal

“…Like the climatic changes, the type, intensity, and frequency of land-use change differ significantly among geographic regions and vegetation types. The land-use changes and climate changes often exhibit complex confounding, compounding or counteracting interactions at different spatial and temporal scales (Goring & Williams 2017;Guo et al 2018). (Fig.…”