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Ph.D., Geography, University of Colorado, Boulder (2016)

M.Sc., Organismal Biology & Ecology, University of Montana (2010)

B.A., Ecology & Evolutionary Biology, Rice University (1998)

I am a landscape ecologist with strong interest in understanding spatio-temporal landscape dynamics of temperate forest ecosystems. I am especially interested in forest disturbances, tree mortality processes, resilience mechanisms, tipping points and cross-scale feedbacks that link vegetation characteristics and functions from tree to landscape scales with other biophysical drivers of spatio-temporal dynamics. My work addresses these themes for both historical and contemporary eras using a combination of field studies, dendroecological techniques, remote sensing technologies, and statistical modeling.

Postdoc Research

Spatio-temporal fire regime dynamics and human drivers of the montane forests of southern Alberta, Canada

 

The Montane Cordillera of southern Alberta’s Front Range is comprised of a mix of grassland, aspen and conifer forests dominated by lodgepole pine, Douglas-fir, and spruce-fir. Traditional models of fire regime dynamics for the region depict a coarse-scale high-severity fire regime that resulted in a shifting mosaic of even-aged forests. This premise forms the basis for evaluations of current ecological conditions and management paradigms in the region. But recent evidence from a number of studies suggests that portions of these forests experienced a mix of fire severities that created more complex stand structures and landscape dynamics. Moreover, there is some evidence that indigenous burning may have substantially altered fire regimes in this region, but no comprehensive evaluation of the mechanism, magnitude or consequences of indigenous burning have been evaluated for our study region. A set of critical questions emerge from this context that we will address in this research, including:

• What proportion of the landscape was driven by high- versus mixed-severity fire regime dynamics?

• How were patches with high- and mixed-severity fire effects interspersed across the landscape and in relation to key biophysical gradients?

• What were the ecological dynamics created by mixed-severity fire regimes?

• How important were indigenous influences on the historical fire regime and landscape vegetation patterns?

To address these questions, we will combine dendroecological reconstructions of historical fire frequency and severity with geospatial maps of the structural characteristics of the patch mosaic built from stereo-photogrammetric point clouds derived from historical aerial photos. This combined dataset will allow us to drive predictive models of patch-level disturbance-related variables (e.g. stand age, fire severity class, cohort structure) that can be applied to the full coverage of our geospatial maps and used to characterize spatio-temporal fire regime dynamics across much broader. These geospatial reconstructions of historical fire severity will be used to calibrate a landscape simulation model of mixed-severity fire regime dynamics that will be used to evaluate landscape responses to alternative management (e.g. indigenous, past Euro-American, future) and climate scenarios.

PhD Dissertation

A cross-scale assessment of historical fire severity patterns, landscape dynamics, and methodological challenges in mixed-severity fire regimes of the northern U.S. Rockies

The ecological dynamics, resilience mechanisms, and distribution of mixed-severity fire regimes in forests of western North America are poorly understood. This is due, in part, to the lack of detailed fire severity reconstructions for many parts of the West and in part to methodological challenges associated with most historical reconstruction methods. These methodological constraints often result in strong tradeoffs between spatial and temporal inferences, limiting the spatio-temporal inferences that are crucial to understanding mixed-severity fire regimes.

To address these challenges, I collected dendroecological records and mapped patch characteristics using historical stereo aerial photos for lower montane forests from two distinct ecological subregions within the northern U.S. Rockies thought to have mixed-severity fire regimes. My study watersheds in the Northern Continental Divide (NCDE) ecoregion, were characterized by warm-wet and cold climate conditions and were comprised by mixed-conifer forests of western larch, Douglas-fir, ponderosa pine and lodgepole pine. My study watersheds in the Greater Yellowstone Ecosystem (GYE) were characterized by cold-dry climates where nearly pure Douglas-fir forest and grassland intermix.

We found striking similarities between the fire regimes of both ecoregions. Fires recurred with intermediate median frequencies (30-50 years) but exhibited high variation (~15-300 years). Over 80% of patches experienced high severity fire but many of these patches subsequently burned at low-moderate severity. Overall, approximately 15%, 45% and 40% of patches in each ecoregion were characterized as low, mixed and high, respectively. The resulting landscape mosaic was comprised of interspersed young (< 100) and intermediate-aged (100-200 years) patches with single-, double- and multi-cohort structures. Old forest (> 200 years) formed a small proportion of the landscape and consisted of a combination of long unburned stands created by old high severity fires and multi-cohort forests created by recurrent non stand-replacing fires.

I also used these dendroecological data to calibrate a machine learning model that used the photo-interpreted forest structural attributes to predict patch-level fire severity class. I then applied this model to five mapped watersheds, totaling over 27,0000 ha, and used these data to characterize patch size distribution of different fire severity classes and estimate the total area of each fire severity class.

SELECTED PUBLICATIONS

Naficy, C.E., E.G. Keeling, P. Landres, P.F. Hessburg, A. Sala, T.T. Veblen. 2016. Wilderness in the 21st century: A framework for testing assumptions about ecological intervention in wilderness using a case study of fire ecology in the Rocky Mountains Journal of Forestry 114(3): 384-395.

Naficy, C.E., T.T. Veblen, and P.F. Hessburg. 2015. Spatially explicit quantification of heterogeneous fire effects over long time series: patterns from two forest types in the northern U.S. Rockies. Pages 168-173 in Proceedings of the large wildland fires conference; May 19-23, 2014; Missoula, MT. RMRS-P-73. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 310 p.