Imaging spectroscopy reveals the effects of topography and logging on the leaf chemistry of tropical forest canopy trees
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Published version
Author(s)
Type
Journal Article
Abstract
Logging, pervasive across the lowland tropics, affects millions of hectares of forest, yet its influence on nutrient cycling remains poorly understood. One hypothesis is that logging influences phosphorus (P) cycling, because this scarce nutrient is removed in extracted timber and eroded soil, leading to shifts in ecosystem functioning and community composition. However, testing this is challenging because P varies within landscapes as a function of geology, topography and climate. Superimposed upon these trends are compositional changes in logged forests, with species with more acquisitive traits, characterized by higher foliar P concentrations, more dominant. It is difficult to resolve these patterns using traditional field approaches alone. Here, we use airborne light detection and ranging‐guided hyperspectral imagery to map foliar nutrient (i.e. P, nitrogen [N]) concentrations, calibrated using field measured traits, over 400 km2 of northeastern Borneo, including a landscape‐level disturbance gradient spanning old‐growth to repeatedly logged forests. The maps reveal that canopy foliar P and N concentrations decrease with elevation. These relationships were not identified using traditional field measurements of leaf and soil nutrients. After controlling for topography, canopy foliar nutrient concentrations were lower in logged forest than in old‐growth areas, reflecting decreased nutrient availability. However, foliar nutrient concentrations and specific leaf area were greatest in relatively short patches in logged areas, reflecting a shift in composition to pioneer species with acquisitive traits. N:P ratio increased in logged forest, suggesting reduced soil P availability through disturbance. Through the first landscape scale assessment of how functional leaf traits change in response to logging, we find that differences from old‐growth forest become more pronounced as logged forests increase in stature over time, suggesting exacerbated phosphorus limitation as forests recover.
Date Issued
2019-12-17
Date Acceptance
2019-10-03
Citation
Global Change Biology, 2019, 26 (2), pp.989-1002
ISSN
1354-1013
Publisher
Wiley
Start Page
989
End Page
1002
Journal / Book Title
Global Change Biology
Volume
26
Issue
2
Copyright Statement
© 2019 The Authors. Global Change Biology published by John Wiley & Sons Ltd
This is an open access article under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
This is an open access article under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Sponsor
Rainforest Research Sdn Bhd
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000502828800001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
LBEE_P34395
Subjects
Science & Technology
Life Sciences & Biomedicine
Biodiversity Conservation
Ecology
Environmental Sciences
Biodiversity & Conservation
Environmental Sciences & Ecology
imaging spectroscopy
leaf traits
logging
nutrient availability
phosphorus
specific leaf area
topography
tropical forest
RAIN-FOREST
SPECIES DISTRIBUTIONS
PHOSPHORUS LIMITATION
NUTRIENT LIMITATION
SQUARES REGRESSION
CHEMICAL TRAITS
MOUNT KINABALU
NITROGEN
DIVERSITY
RESPONSES
Publication Status
Published
Date Publish Online
2019-12-17