Integrating remote sensing and demography for more efficient and effective assessment of changing mountain forest distribution

Abstract

Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. A B S T R A C TSpecies range shifts have been well studied in light of rising global temperatures and the role climate plays in restricting species distribution. In mountain regions, global trends show upward elevational shifts of altitudinal treelines. However, there is significant variation in response between geographic locations driven by climatic and habitat heterogeneity and biotic interactions. Accurate estimation of treeline shifts requires fine-scale patterns of forest structure to be discriminated across mountain ranges. Satellite remote sensing allows detailed information on forest structure to be extrapolated across mountain ranges, however, variation in methodology combined with a lack of information on accuracy and repeatability has led to high uncertainty in the utility of remotely sensed data in studies of mountain treelines. We unite three themes; suitability of remote sensing products, ecological relevance of classifications and effectiveness of the training and validation process in relation to the study of mountain treeline ecotones. We identify needs for further research comparing the utility of different remotely sensed data sets, better characterisation of treeline structure and incorporation of accuracy assessment. Collectively, the improvements we describe will significantly improve the utility of remote sensing by facilitating a more consistent approach to defining geographic variation in treeline structure, improving our ability to link processes from stand to regional scale and the accuracy of range shift assessments. Ultimately, this advance will enable better monitoring of mountain treeline shifts and estimation of the associated to biodiversity and ecosystem function.

Montane forest expansion at high elevations drives rapid reduction in non‐forest area, despite no change in mean forest elevation

“…Feuillet et al, 2020;Klasner & Fagre, 2002;Luo & Dai, 2013;Mathisen et al, 2014;Resler, Fonstad, & Butler, 2004). However, variation in the methods used to analyse aerial photography data alongside a lack of quantitative estimates of uncertainty in the range shifts reported limits the interpretation of the results, and hinders landscape-scale estimation of changes in forest K E Y W O R D S climate change, densification, forest change, migration, mountain, range edge, Taiwan, tree line distribution in mountain ecosystems (Morley, Donoghue, Chen, & Jump, 2018).…”

High intraspecific trait variation results in a resource allocation spectrum of a subtropical pine across an elevational gradient

“…Elevational patterns can be complex and nonlinear, with traits influenced by several interacting drivers such as competition, ecosystem productivity, soil moisture and fertility, clear‐sky turbidity, hours of sunshine, wind, season length, geology and human land use (Körner, 2007; Sundqvist et al, 2013). Mountains are highly heterogeneous, with environmental controls differing across local, regional and continental scales (Jobbágy et al, 1996; Midolo et al, 2019; Morley et al, 2018; Sundqvist et al, 2013). Fundamental elevational trends may not hold across latitudes, with information on trait variation in the tropics limited compared to temperate northern hemisphere regions (Wilson et al, 1999, Jetz et al, 2016, but see Chaturvedi et al, 2011; Poorter et al, 2008; Wright et al, 2010).…”

Spatial Distribution and Climate Warming Impact on Abies kawakamii Forest on a Subtropical Island

“…Among them, A. kawakamii is an endemic and relic tree species that composes monodominant forest and builds forest lines in high mountain areas in subtropical Taiwan [ 23 , 24 , 25 , 26 , 27 ]. It plays an essential role in the subalpine ecosystem and presents a unique forest landscape [ 28 , 29 ]. Plants at high altitudes are susceptible to climate change [ 30 , 31 ] and rarely have the opportunity to migrate upwards under warming conditions [ 32 , 33 , 34 ].…”