Patterns and drivers of recent disturbances across the temperate forest biome

Andreas Sommerfeld,Jörg Müller,Andrés Holz,Álvaro G Gutiérrez,Ignacio Díaz-Hormazábal,Tiphaine Després,Hong S He,Sarah J Hart,Tomáš Hlásny,Anthony W D’Amato,Scott L Stephens,Brian Buma,Cornelius Senf,Miroslav Svoboda,Brian Harvey ,Lee E Frelich,Juan Paritsis,George L Perry ,Dominik Kulakowski,Thomas T Veblen,Monica G Turner,Akira Mori ,Shawn Fraver,David B Lindenmayer ,Thomas Kitzberger,Rupert Seidl

doi:10.1038/s41467-018-06788-9

Abstract

Increasing evidence indicates that forest disturbances are changing in response to global change, yet local variability in disturbance remains high. We quantified this considerable variability and analyzed whether recent disturbance episodes around the globe were consistently driven by climate, and if human influence modulates patterns of forest disturbance. We combined remote sensing data on recent (2001–2014) disturbances with in-depth local information for 50 protected landscapes and their surroundings across the temperate biome. Disturbance patterns are highly variable, and shaped by variation in disturbance agents and traits of prevailing tree species. However, high disturbance activity is consistently linked to warmer and drier than average conditions across the globe. Disturbances in protected areas are smaller and more complex in shape compared to their surroundings affected by human land use. This signal disappears in areas with high recent natural disturbance activity, underlining the potential of climate-mediated disturbance to transform forest landscapes.

Highlights

Increasing evidence indicates that forest disturbances are changing in response to global change, yet local variability in disturbance remains high
Unsupervised cluster analysis identified three distinct groups of landscapes based on their recent disturbance dynamics (Table 1; Supplementary Figure 1), which we in the following refer to as low, moderate, and high disturbance activity clusters
Only 9 of the 50 landscapes analyzed fell within the high disturbance activity cluster, they accounted for 49.5% of the total forest area under study

Summary

Introduction

Increasing evidence indicates that forest disturbances are changing in response to global change, yet local variability in disturbance remains high. While an in-depth understanding of disturbance dynamics exists for a growing number of landscapes (i.e., contiguous land areas of roughly between 103 and 106 ha) around the globe, their responses to global drivers have not consistently been compared to date Questions such as whether recent bark beetle outbreaks in North America differ from those in Europe with regard to their climate sensitivity, or whether recent fires in Australia created similar patterns as those in the Americas remain largely unexplored. Comparing the variation in disturbance patterns and their relationship to climate variability among landscapes at subcontinental to global scales[14,15] has the potential to elucidate whether recent disturbance episodes were consistently driven by climate across continents, or whether climate sensitivities differ between systems Such a comparison can shed light on how regionalto continental-scale drivers such as climate variability interact with local factors such as the topographic template of a landscape[16] and the influence of human land use[17]. Focusing our network of landscapes on protected areas and their surroundings allowed us to isolate patterns of natural disturbances (inside protected areas) from those of areas where natural and human disturbances a

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Conclusion