A Conceptual Model for Detecting Small-Scale Forest Disturbances Based on Ecosystem Morphological Traits

Current LiDAR-based methods for detecting forest change use a host of statistically selected variables which typically lack a biological link with the characteristics of the ecosystem. Consensus of the literature indicates that many authors use LiDAR to derive ecosystem morphological traits (EMTs)—n...

Full description

Bibliographic Details
Main Authors: Jaz Stoddart, Danilo Roberti Alves de Almeida, Carlos Alberto Silva, Eric Bastos Görgens, Michael Keller, Ruben Valbuena
Format: Article
Language:English
Published: MDPI AG 2022-02-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/14/4/933
_version_ 1797476806025019392
author Jaz Stoddart
Danilo Roberti Alves de Almeida
Carlos Alberto Silva
Eric Bastos Görgens
Michael Keller
Ruben Valbuena
author_facet Jaz Stoddart
Danilo Roberti Alves de Almeida
Carlos Alberto Silva
Eric Bastos Görgens
Michael Keller
Ruben Valbuena
author_sort Jaz Stoddart
collection DOAJ
description Current LiDAR-based methods for detecting forest change use a host of statistically selected variables which typically lack a biological link with the characteristics of the ecosystem. Consensus of the literature indicates that many authors use LiDAR to derive ecosystem morphological traits (EMTs)—namely, vegetation height, vegetation cover, and vertical structural complexity—to identify small-scale changes in forest ecosystems. Here, we provide a conceptual, biological model for predicting forest aboveground biomass (AGB) change based on EMTs. We show that through use of a multitemporal dataset it is possible to not only identify losses caused by logging in the period between data collection but also identify regions of regrowth from prior logging using EMTs. This sensitivity to the change in forest dynamics was the criterion by which LiDAR metrics were selected as proxies for each EMT. For vegetation height, results showed that the top-of-canopy height derived from a canopy height model was more sensitive to logging than the average or high percentile of raw LiDAR height distributions. For vegetation cover metrics, lower height thresholds for fractional cover calculations were more sensitive to selective logging and the regeneration of understory. For describing the structural complexity in the vertical profile, the Gini coefficient was found to be superior to foliage height diversity for detecting the dynamics occurring over the years after logging. The subsequent conceptual model for AGB estimation obtained a level of accuracy which was comparable to a model that was statistically optimised for that same area. We argue that a widespread adoption of an EMT-based conceptual approach would improve the transferability and comparability of LiDAR models for AGB worldwide.
first_indexed 2024-03-09T21:08:56Z
format Article
id doaj.art-275bdf26e21c4c88abc3be20827c4221
institution Directory Open Access Journal
issn 2072-4292
language English
last_indexed 2024-03-09T21:08:56Z
publishDate 2022-02-01
publisher MDPI AG
record_format Article
series Remote Sensing
spelling doaj.art-275bdf26e21c4c88abc3be20827c42212023-11-23T21:54:22ZengMDPI AGRemote Sensing2072-42922022-02-0114493310.3390/rs14040933A Conceptual Model for Detecting Small-Scale Forest Disturbances Based on Ecosystem Morphological TraitsJaz Stoddart0Danilo Roberti Alves de Almeida1Carlos Alberto Silva2Eric Bastos Görgens3Michael Keller4Ruben Valbuena5School of Natural Sciences, Bangor University, Bangor LL57 2DG, UKSchool of Natural Sciences, Bangor University, Bangor LL57 2DG, UKForest Biometrics and Remote Sensing Lab (Silva Lab), School of Forest, Fisheries, and Geomatics Sciences, University of Florida, Gainesville, FL 32611, USADepartment of Forest Engineering, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Alto da Jucuba, Campus JK, Diamantina 39100-000, MG, BrazilUSDA-Forest Service International Institute of Tropical Forestry, Jardin Botanico Sur, 1201 Calle Ceiba, San Juan, PR 00926, USASchool of Natural Sciences, Bangor University, Bangor LL57 2DG, UKCurrent LiDAR-based methods for detecting forest change use a host of statistically selected variables which typically lack a biological link with the characteristics of the ecosystem. Consensus of the literature indicates that many authors use LiDAR to derive ecosystem morphological traits (EMTs)—namely, vegetation height, vegetation cover, and vertical structural complexity—to identify small-scale changes in forest ecosystems. Here, we provide a conceptual, biological model for predicting forest aboveground biomass (AGB) change based on EMTs. We show that through use of a multitemporal dataset it is possible to not only identify losses caused by logging in the period between data collection but also identify regions of regrowth from prior logging using EMTs. This sensitivity to the change in forest dynamics was the criterion by which LiDAR metrics were selected as proxies for each EMT. For vegetation height, results showed that the top-of-canopy height derived from a canopy height model was more sensitive to logging than the average or high percentile of raw LiDAR height distributions. For vegetation cover metrics, lower height thresholds for fractional cover calculations were more sensitive to selective logging and the regeneration of understory. For describing the structural complexity in the vertical profile, the Gini coefficient was found to be superior to foliage height diversity for detecting the dynamics occurring over the years after logging. The subsequent conceptual model for AGB estimation obtained a level of accuracy which was comparable to a model that was statistically optimised for that same area. We argue that a widespread adoption of an EMT-based conceptual approach would improve the transferability and comparability of LiDAR models for AGB worldwide.https://www.mdpi.com/2072-4292/14/4/933vegetation structurecarbon stockLiDARmodelling
spellingShingle Jaz Stoddart
Danilo Roberti Alves de Almeida
Carlos Alberto Silva
Eric Bastos Görgens
Michael Keller
Ruben Valbuena
A Conceptual Model for Detecting Small-Scale Forest Disturbances Based on Ecosystem Morphological Traits
Remote Sensing
vegetation structure
carbon stock
LiDAR
modelling
title A Conceptual Model for Detecting Small-Scale Forest Disturbances Based on Ecosystem Morphological Traits
title_full A Conceptual Model for Detecting Small-Scale Forest Disturbances Based on Ecosystem Morphological Traits
title_fullStr A Conceptual Model for Detecting Small-Scale Forest Disturbances Based on Ecosystem Morphological Traits
title_full_unstemmed A Conceptual Model for Detecting Small-Scale Forest Disturbances Based on Ecosystem Morphological Traits
title_short A Conceptual Model for Detecting Small-Scale Forest Disturbances Based on Ecosystem Morphological Traits
title_sort conceptual model for detecting small scale forest disturbances based on ecosystem morphological traits
topic vegetation structure
carbon stock
LiDAR
modelling
url https://www.mdpi.com/2072-4292/14/4/933
work_keys_str_mv AT jazstoddart aconceptualmodelfordetectingsmallscaleforestdisturbancesbasedonecosystemmorphologicaltraits
AT danilorobertialvesdealmeida aconceptualmodelfordetectingsmallscaleforestdisturbancesbasedonecosystemmorphologicaltraits
AT carlosalbertosilva aconceptualmodelfordetectingsmallscaleforestdisturbancesbasedonecosystemmorphologicaltraits
AT ericbastosgorgens aconceptualmodelfordetectingsmallscaleforestdisturbancesbasedonecosystemmorphologicaltraits
AT michaelkeller aconceptualmodelfordetectingsmallscaleforestdisturbancesbasedonecosystemmorphologicaltraits
AT rubenvalbuena aconceptualmodelfordetectingsmallscaleforestdisturbancesbasedonecosystemmorphologicaltraits
AT jazstoddart conceptualmodelfordetectingsmallscaleforestdisturbancesbasedonecosystemmorphologicaltraits
AT danilorobertialvesdealmeida conceptualmodelfordetectingsmallscaleforestdisturbancesbasedonecosystemmorphologicaltraits
AT carlosalbertosilva conceptualmodelfordetectingsmallscaleforestdisturbancesbasedonecosystemmorphologicaltraits
AT ericbastosgorgens conceptualmodelfordetectingsmallscaleforestdisturbancesbasedonecosystemmorphologicaltraits
AT michaelkeller conceptualmodelfordetectingsmallscaleforestdisturbancesbasedonecosystemmorphologicaltraits
AT rubenvalbuena conceptualmodelfordetectingsmallscaleforestdisturbancesbasedonecosystemmorphologicaltraits