The Effects of Spatial Legacies following Shifting Management Practices and Fire on Boreal Forest Age Structure

Abstract

Forest age structure and its spatial arrangement are important elements of sustainable forestry because of their effects on biodiversity and timber availability. Forest management objectives that include specific forest age structure may not be easily attained due to constraints imposed by the legacies of historical management and natural disturbance. We used a spatially explicit stochastic model to explore the synergetic effects of forest management and fire on boreal forest age structure. Specifically, we examined (1) the duration of spatial legacies of different management practices in the boreal forest, (2) how multiple shifts in management practices affect legacy duration and the spatial trajectories of forest age structure, and (3) how fire influences legacy duration and pattern development in combination with harvesting. Results based on 30 replicates of 500 years for each scenario indicate that (1) spatial legacies persist over 200 years and the rate at which legacies are overcome depends on whether new management targets are in synchrony with existing spatial pattern; (2) age specific goals were met faster after multiple management shifts due to the similar spatial scale of the preceding management types; (3) because large fires can erase the spatial pattern created by smaller disturbances, scenarios with fire had shorter lags than scenarios without fire. These results suggest that forest management goals can be accelerated by applying management at a similar spatial scale as existing spatial patterns. Also, management planning should include careful consideration of historical management as well as current and likely future disturbances.

Estimating effective landscape distances and movement corridors: comparison of habitat and genetic data

“…Spatial-genetic structure within populations is likely less dependent on the resistance of the landscape matrix (Fahrig 2007), but more strongly influenced by many other biological and ecological factors acting locally, including sex-specific space-use behavior, local population density, survival, or reproductive success (Pflü ger and Balkenhol 2014). Another issue related to genetic data is that in long-lived species there may be a temporal disconnection between genetic structure and the current landscape; i.e., there may be legacy effects of previous landscapes (James et al 2007, Spear et al 2010) that could lead to misestimate current connectivity. However, Landguth et al (2010) showed that the legacy of past landscape features is not a particularly important problem in species with relatively large dispersal abilities.…”

Process‐based models are required to manage ecological systems in a changing world

“…Past abiotic events, spatial configuration and species assemblages are known to constrain subsequent ecological processes (known as legacy effects; Peterson 2002, James et al 2007, Cuddington 2012.…”

Fire models and methods to map fuel types: The role of remote sensing

“…Even though it is more time-consuming than newer approaches, aerial photo interpretation is a good compromise between costs and precision, particularly when working at fine scales. As a consequence, it is currently widely employed by governmental agencies and forest managers (James et al, 2007).…”