A Burning Question: Can Long-term Data Inform Fire Management in the Twenty-first Century? - Biodiversity Conservation and Environmental Change - page 75

mild and wet climate leads to high biomass accumulation and infrequent fires, with return
intervals varying from 200 to over 1,000 years, depending on rainfall (Noss et al. 2006). Over
centuries, structural complexity builds up due to accumulating dead wood, diverse under-
stories, mature trees, and localized disturbance by windthrow (Franklin and Johnson 2011).
Due to frequent logging and development, the extent of old-growth forests has been
reduced dramatically, and fire regimes have been disrupted (North and Keeton 2008). The
Northwest Forest Plan aims to promote the recovery of late succession and old-growth forests
and restore structural complexity and landscape connectivity. However, fire return intervals
are poorly understood and it is not always clear how much old-growth forest was typical,
prior to Anthropocene disturbances. Wimberly et al. (2000) modelled historic variability in
fire regimes based on charcoal records from lake sediments in the Oregon Coastal Range.
They also simulated past forest age structure using palaeoecological and dendroecological
information, and concluded that recent declines in the amount of old-growth forest were
unprecedented in the past 3,000 years. Their study provided information that could inform
the restoration and management of forests, providing guidance as to the range of variability
in old growth forest extent, and the effect of changing fire frequency and configuration (Wim-
berly et al. 2000).
Integrate palaeo- and neoecology across scales to maximize resilience
and biodiversity
Long-term records from charcoal and dendrochronology can provide guidance for fire res-
toration, but this must be set alongside modern ecological studies that take into account
the complex interplay between vegetation, fire frequency, intensity, type, and configur-
ation, as well as the effects of topography and local hydrology. Knowledge of broad-scale
climatic drivers needs to be integrated with landscape—local knowledge of environment,
ecology, and disturbance history (Whitlock et al. 2010). Patterns of synchrony in fire history
and vegetation change may emerge at regional scales due to the influence of similar cli-
matic patterns, but break down at landscape-local scales due to variations in fuel dynam-
ics, ignition histories, and local disturbance, which interact to create heterogeneous fire
regimes and abrupt changes in vegetation (Gavin et al. 2007, Whitlock et al. 2010, Williams
et al. 2011). Understanding spatial complexity requires comparison of multiple palaeo-
records across landscapes and regions, to reconstruct the interacting effects of local distur-
bance and regional-global climate on ecological patterns and tipping points (Roccaforte
et al. 2008, Long 2009, Whitlock et al. 2010, Williams et al. 2011).
Natural disturbance regimes are sometimes difficult to implement because ecological leg-
acies have changed forest structure and human management may have homogenized spatial
and temporal complexity and age composition. Restoring complex landscape mosaics
requires detailed palaeoecological investigation that takes account of local context (Rocca-
forte et al. 2008, Long 2009, Whitlock et al. 2010). For example, Williams and Baker (2013)
reconstructed ponderosa pine forest structure and fire regimes across the landscape of the
Cocconino Plateau, Grand Canyon National Park, Arizona, and found evidence of a mosaic of