Landscape Patterns of Vegetation Canopy Regrowth Following Wildfires in the Sierra Nevada Mountains of California

Christopher Potter

doi:10.4236/ojf.2015.57064

Abstract

Rapid recovery of pioneer shrub and forest patch cover can reduce soil erosion, nutrient runoff and degradation of stream habitats, and promote small mammal and avian biodiversity following stand-replacing wildfires. Landsat imagery from the past 25+ years was analyzed to understand patterns and rates of vegetation recovery, focusing on high burn severity (HBS) patches, within wildfire areas dating from the late 1940s in the Sierra-Nevada region of California. Normalized difference vegetation index (NDVI) levels indicative of recovered woody cover within HBS areas were analyzed starting in 1985 to quantify regrowth of patch dynamics. Analysis of landscape metrics showed that the percentage of total HBS area comprised by the largest patch of recovered woody cover was relatively small in all fires that occurred since 1995, but increased rapidly with time since fire. Patch complexity of recovered woody cover decreased notably after more than 50 years of regrowth, but was not readily associated with time for fires that occurred since the mid 1990s. Patch complexity of dense woody cover was consistently high in fires after 1995 and increased with the elevation of HBS areas. The aggregation level of patches with recovery of woody cover increased steadily with time since fire. The study approach using satellite remote sensing can be expanded to assess the consequences of stand-replacing wildfires in all forests of the region.

Highlights

Wildfire is a major force in determining the structure of forests in the Sierra Nevada of California (Kane et al., How to cite this paper: Potter, C. (2015)
The spatial patterns of all high burn severity (HBS) class areas with high Normalized difference vegetation index (NDVI) was shown in Figure 2 for visual comparisons of each of the fires selected for analysis
The proportion of HBS class area with high NDVI values (>0.5) in 2013 was greater than 69% for the two fires that occurred in the late 1990s, Ackerson and Bucks (Table 1)

Summary

Introduction

Wildfire is a major force in determining the structure of forests in the Sierra Nevada of California (Kane et al., How to cite this paper: Potter, C. (2015). Landscape Patterns of Vegetation Canopy Regrowth Following Wildfires in the Sierra Nevada Mountains of California. Satellite remote sensing has been shown to be an effective method to monitor regeneration patterns of vegetation biomass and productivity following disturbance in remote mountain areas (Collins & Woodcock, 1996; Amiro et al, 2000; Rogan & Franklin, 2001; Rogan et al, 2003; Fischer et al, 2004; Epting & Verbyla, 2005; Cuevas-Gonzalez et al, 2009; Casady & Marsh, 2010, Li & Potter, 2012; Potter, 2014)

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