Data from: Deterministic and stochastic processes lead to divergence in plant communities 25 years after the 1988 Yellowstone fires

Young, recently burned forests are increasingly widespread throughout western North America, but forest development after large wildfires is not fully understood, especially regarding effects of variable burn severity, environmental heterogeneity, and changes in drivers over time. We followed development of subalpine forests after the 1988 Yellowstone fires by periodically re-sampling permanent plots established soon after the fires. We asked two questions about patterns and processes over the past 25 years: (1) Are plant species richness and community composition converging or diverging across variation in elevation, soils, burn severity, and post-fire lodgepole pine (Pinus contorta var. latifolia) density? (2) What are the major controls on post-fire species composition, and has the relative importance of controls changed over time? For question 1, we sampled 10-m2 plots (n=552) distributed among three geographic areas that differ in elevation and substrate; plots spanned the spectrum of fire severities and were re-sampled periodically from 1991-2013. For question 2, we sampled 0.25-ha plots (n=72), broadly distributed across areas that burned as stand-replacing fire, in 1999 and 2012. Richness and species composition diverged early on between infertile low-elevation areas (lower richness) and more fertile high-elevation areas (greater richness). Richness increased rapidly for the first five years post-fire, then leveled off or increased only slowly thereafter. Only 6% of 227 recorded species were non-native. Some annuals and species with heat-stimulated soil seed banks were associated with severely burned sites. However, most post-fire species had been present before the fire; many survived as roots or rhizomes and regenerated rapidly by sprouting. Among the 72 plots, substrate, temperature, and precipitation (the abiotic template) were consistently important drivers of community composition in 1999 and 2012. Post-fire lodgepole pine abundance was not significant in 1999 but was the most important driving variable by 2012, with a negative effect on presence of most understory species, especially annuals and shade-intolerant herbs. Burn severity was significant in 1999 but not in 2012, and distance to unburned forest had no influence in either year. The 1988 fires did not fundamentally alter subalpine forest community assemblages in Yellowstone, and ecological memory conferred resilience to high-severity fire.YNP postfire species 1991-2013 metadataThis Word file explains the data-set contained in the associated Excel file (YNP 1991-2013 Data Dryad.xlsx). The data consist of all vascular plant species, locations, and dates, as recorded in permanent plots established soon after the 1988 Yellowstone fires and periodically re-sampled from 1991-2013.YNP 1991-2013 Metadata Dryad.docxYNP postfire species 1991-2013 dataThis Excel file contains listings of all vascular plant species, locations, and dates, as recorded in permanent plots established soon after the 1988 Yellowstone fires and periodically re-sampled from 1991-2013. See the associated metadata file (YNP 1991-2013 Metadata Dryad.docx) for detailed explanation.YNP 1991-2013 Data Dryad.xlsxYNP postfire controls 1999-2012 metadataThis Word file explains the associated data file (YNP 1999-2012 Data Dryad.xlsx). That data file contains listings of species recorded in extensive permanent plots sampled in 1999 and 2012, plus values of abiotic and biotic variables that could potentially influence local species composition.YNP 1999-2012 Metadata Dryad.docxYNP postfire controls 1999-2012 dataThis data file contains listings of species recorded in extensive permanent plots sampled in 1999 and 2012, plus values of abiotic and biotic variables that could potentially influence local species composition. See the associated metadata file (YNP 1999-2012 Metadata Dryad.docx) for detailed explanation.YNP 1999-2012 Data Dryad.xls