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The size and severity of the fires in Yellowstone National Park in 1988 surprised ecologists and managers alike. Much has been learned about the causes and consequences of crown fires from studies of the Yellowstone fires, and some results were surprising. Plant cover in burned areas was restored rapidly by native species, making post‐fire rehabilitation generally unnecessary and possibly even counterproductive. While 20th‐century fire suppression has affected systems like Yellowstone far less than other ecosystems, managing forests, people, and property in wildfire areas is an ongoing challenge. Insights gained and lessons learned from the Yellowstone fires may be applied elsewhere and can help inform fire policy.

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A warming climate may increase the frequency and severity of stand-replacing wildfires, reducing carbon (C) storage in forest ecosystems. Understanding the variability of postfire C cycling on heterogeneous landscapes is critical for predicting changes in C storage with more frequent disturbance. We measured C pools and fluxes for 77 lodgepole pine (Pinus contorta Dougl. ex Loud var. latifolia Engelm.) stands in and around Yellowstone National Park (YNP) along a 300-year chronosequence to examine how quickly forest C pools recover after a stand-replacing fire, their variability through time across a complex landscape, and the role of stand structure in this variability.Carbon accumulation after fire was rapid relative to the historical mean fire interval of 150-300 years, recovering nearly 80% of prefire C in 50 years and 90% within 100 years. Net ecosystem carbon balance (NECB) declined monotonically, from 160 g CÁm À2 Áyr À1 at age 12 to 5 g CÁm À2 Áyr À1 at age 250, but was never negative after disturbance. Decomposition and accumulation of dead wood contributed little to NECB relative to live biomass in this system. Aboveground net primary productivity was correlated with leaf area for all stands, and the decline in aboveground net primary productivity with forest age was related to a decline in both leaf area and growth efficiency. Forest structure was an important driver of ecosystem C, with ecosystem C, live biomass C, and organic soil C varying with basal area or tree density in addition to forest age. Rather than identifying a single chronosequence, we found high variability in many components of ecosystem C stocks through time; a .50% random subsample of the sampled stands was necessary to reliably estimate the nonlinear equation coefficients for ecosystem C. At the spatial scale of YNP, this variability suggests that landscape C develops via many pathways over decades and centuries, with prior stand structure, regeneration, and within-stand disturbance all important. With fire rotation projected to be ,30 years by mid century in response to a changing climate, forests in YNP will store substantially less C (at least 4.8 kg C/m 2 or 30% less).

A 1992 study of serotiny in lodgepole pine (Pinuscontorta Dougl. ex Loud. var. latifolia Engelm.) in Yellowstone National Park asked four questions: (i) are there morphological characteristics that can be used to estimate pre-fire proportion of serotinous trees in forests that burned in 1988?; (ii) at what spatial scale does percent serotinous trees vary across the landscape?; (iii) which environmental factors are correlated with serotiny?; and (iv) what is the relationship between prefire serotiny and postfire lodgepole pine seedling density? We first sampled cone characteristics in serotinous and nonserotinous trees along four 2950-m transects in unburned forests, and examined burned trees nearby. Results indicated that asymmetrical cones and an acute angle of cone attachment to the branch were reliable indicators of serotiny even in burned trees. We then sampled nine patches of lodgepole pine forest that had burned in 1988, and varied in size from 1–3600 ha. We sampled serotiny at varying intervals along two perpendicular transects that crossed in the center of each patch. At each sample point, the 12 nearest canopy lodgepole pines were classified as serotinous or nonserotinous. We concluded that the percentage of serotinous trees is most variable at intermediate scales of 1–10 km, and is relatively homogeneous at both fine scales (<1 km) and at very broad scales (tens of kilometers). Percent serotiny was generally more variable and greater at low to middle elevations. Prefire density of serotinous trees was a more important predictor of postfire seedling density than aspect, slope, or soil type. These findings have important implications for landscape-level patterns in postfire regeneration of lodgepole pine.