Publications

@article{Chen2015,
title = {Mapping burn severity in a disease-impacted forest landscape using Landsat and MASTER imagery},
author = {Gang Chen and Margaret R. Metz and David M. Rizzo and Ross K. Meentemeyer},
url = {http://www.sciencedirect.com/science/article/pii/S0303243415000847},
doi = {dx.doi.org/10.1016/j.jag.2015.04.005},
year = {2015},
date = {2015-04-22},
journal = {International Journal of Applied Earth Observation and Geoinformation},
volume = {40},
pages = {91-99},
abstract = {Global environmental change has increased forest vulnerability to the occurrence of interacting disturbances, including wildfires and invasive diseases. Mapping post-fire burn severity in a disease-affected forest often faces challenges because burned and infested trees may exhibit a high similarity in spectral reflectance. In this study, we combined (pre- and post-fire) Landsat imagery and (post-fire) high-spectral resolution airborne MASTER data [MODIS (moderate resolution imaging spectroradiometer)/ASTER (advanced spaceborne thermal emission and reflection radiometer)] to map burn severity in a California coastal forest environment, where a non-native forest disease sudden oak death (SOD) was causing substantial tree mortality. Results showed that the use of Landsat plus MASTER bundle performed better than using the individual sensors in most of the evaluated forest strata from ground to canopy layers (i.e., substrate, shrubs, intermediate-sized trees, dominant trees and average), with the best model performance achieved at the dominant tree layer. The mid to thermal infrared spectral bands (3.0–12.5 μm) from MASTER were found to augment Landsat’s visible to shortwave infrared bands in burn severity assessment. We also found that infested and uninfested forests similarly experienced moderate to high degrees of burns where CBI (composite burn index) values were higher than 1. However, differences occurred in the regions with low burn severity (CBI values lower than 1), where uninfested stands revealed a much lower burn effect than that in infested stands, possibly due to their higher resilience to small fire disturbances as a result of higher leaf water content.},
keywords = {burn severity, forest fire, interacting disturbances, invasion, Landsat, MASTER, sudden oak death},
pubstate = {published},
tppubtype = {article}
}

@article{Dillon2013,
title = {Rangewide risks to a foundation tree species from disturbance interactions},
author = {Whalen W. Dillon and John B. Vogler and Richard C. Cobb and David M. Rizzo and Ross K. Meentemeyer},
url = {http://dx.doi.org/10.3120/0024-9637-60.2.139},
doi = {10.3120/0024-9637-60.2.139},
year = {2013},
date = {2013-04-01},
journal = {Madrono},
volume = {60},
number = {2},
pages = {139-150},
abstract = {The geographic range of tanoak, Notholithocarpus densiflorus (Hook. & Arn.) Manos, Cannon & S. H. Oh (Fagaceae), encompasses tremendous physiographic variability, diverse plant communities, and complex disturbance regimes (e.g., development, timber harvest, and wildfire) that now also include serious threats posed by the invasive forest pathogen Phytophthora ramorum S. Werres, A.W.A.M. de Cock. Knowing where these disturbance factors interact is critical for developing comprehensive strategies for conserving the abundance, structure, and function of at-risk tanoak communities. In this study, we present a rule-based spatial model of the range-wide threat to tanoak populations from four disturbance factors that were parameterized to encode their additive effects and two-way interactions. Within a GIS, we mapped threats posed by silvicultural activities; disease caused by P. ramorum; human development; and altered fire regimes across the geographic range of tanoak, and we integrated spatially coinciding disturbances to quantify and map the additive and interacting threats to tanoak. We classified the majority of tanoak's range at low risk (3.7 million ha) from disturbance interactions, with smaller areas at intermediate (222,795 ha), and high (10,905 ha) risk. Elevated risk levels resulted from the interaction of disease and silviculture factors over small extents in northern California and southwest Oregon that included parts of Hoopa and Yurok tribal lands. Our results illustrate tanoak populations at risk from these interacting disturbances based on one set of hypothesized relationships. The model can be extended to other species affected by these factors, used as a guide for future research, and is a point of departure for developing a comprehensive understanding of threats to tanoak populations. Identifying the geographic location of disturbance interactions and risks to foundation species such as tanoak is critical for prioritizing and targeting conservation treatments with limited resources.},
keywords = {decision support system, forest disease, forest ecosystems, forest fire, foundation species, landscape epidemiology, Notholithocarpus densiflorus, sudden oak death},
pubstate = {published},
tppubtype = {article}
}