Wildfire Return Intervals: Understanding Impacts of Climate Mediated Shortening of Fire Intervals in Boreal Peatlands in Central Alberta using Multi-Spectral and Multi-Temporal Lidar
Abstract
Historically, peatlands in central Alberta, Canada, burn every 100-130 years, but expected increases in fire frequency due to increased climatic aridity may shorten this return interval. Changes to wildfire regimes may alter the trajectory of re-establishing plant communities and future fire fuel patterns, possibly changing ecosystem function. Ecological effects of the peatland post-fire environment within a typical return interval are relatively well documented, but little is known about how increasing burn frequency may impact early successional vegetation communities. The overall objective of this study is to identify and quantify the structural changes and the rates of change in post-fire successional landscapes and peatland vegetation regeneration within single and double burns using a time-series analysis of airborne lidar data. Based on the hydrologic interactions and regeneration patterns of drained and burned peatlands in other studies we expected early regenerating peatland vegetation in double-burn (relative to single-burn) areas to have: greater variability in structural attributes, increased deciduous species return, and increased rates of change. The Utikuma Region Study Area (URSA), underwent two major wildfires in 1956 and 2011, with their extents overlapping within a 12 km2 area of mixed forests and peatlands. Time-series lidar data spanning a 17-year period include non-recently burned areas, the individual burn scars of 1956 and 2011, and overlapping burn scars (here-in denoted double burns), both pre- and post-2011. In July 2019, field data was collected at 30 peatlands coinciding with the 2019 lidar mission over the study area. We find mean canopy height of regenerating vegetation in double burns to be significantly higher, in addition to being more variable than those of single burns. Using airborne lidar data, we quantify the range of structural vegetation regeneration within remote boreal peatlands and compare these results to in-situ field-based measurements. A time-series analysis of lidar-derived vegetation characteristics allows for an interpretation of the rate of change in the double burn and single burn areas. This research aims to further understanding of how or if peatlands may be expected to change under increasingly severe fire regimes within the boreal forest.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMB044...07J
- Keywords:
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- 3390 Wildland fire model;
- ATMOSPHERIC PROCESSES;
- 0439 Ecosystems;
- structure and dynamics;
- BIOGEOSCIENCES;
- 0468 Natural hazards;
- BIOGEOSCIENCES;
- 0480 Remote sensing;
- BIOGEOSCIENCES