Reuse of field data in ALS-assisted forest inventory

Forest inventories assisted by wall-to-wall airborne laser scanning (ALS), have become common practice in many countries. One major cost component in these inventories is the measurement of field sample plots used for constructing models relating biophysical forest attributes to metrics d...

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Main Authors: de Lera Garrido, Ana, Gobakken, Terje, Ørka, Hans, Næsset, Erik, Bollandsås, Ole
Format: Article
Language:English
Published: Finnish Society of Forest Science 2020-01-01
Series:Silva Fennica
Online Access:https://www.silvafennica.fi/article/10272
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spelling doaj-dd0935b3882c4dec9ea5df61ad20cf5b2020-11-25T03:37:34ZengFinnish Society of Forest ScienceSilva Fennica2242-40752020-01-0154510.14214/sf.10272Reuse of field data in ALS-assisted forest inventoryde Lera Garrido, AnaGobakken, TerjeØrka, HansNæsset, ErikBollandsås, Ole Forest inventories assisted by wall-to-wall airborne laser scanning (ALS), have become common practice in many countries. One major cost component in these inventories is the measurement of field sample plots used for constructing models relating biophysical forest attributes to metrics derived from ALS data. In areas where ALS-assisted forest inventories are planned, and in which the previous inventories were performed with the same method, reusing previously acquired field data can potentially reduce costs, either by (1) temporally transferring previously constructed models or (2) projecting field reference data using growth models that can serve as field reference data for model construction with up-to-date ALS data. In this study, we analyzed these two approaches of reusing field data acquired 15 years prior to the current ALS acquisition to estimate six up-to-date forest attributes (dominant tree height, mean tree height, stem number, stand basal area, volume, and aboveground biomass). Both approaches were evaluated within small stands with sizes of approximately 0.37 ha, assessing differences between estimates and ground reference values. The estimates were also compared to results from an up-to-date forest inventory relying on concurrent field- and ALS data. The results showed that even though the reuse of historical information has some potential and could be beneficial for forest inventories, systematic errors may appear prominent and need to be overcome to use it operationally. Our study showed systematic trends towards the overestimation of lower-range ground references and underestimation of the upper-range ground references.https://www.silvafennica.fi/article/10272
collection DOAJ
language English
format Article
sources DOAJ
author de Lera Garrido, Ana
Gobakken, Terje
Ørka, Hans
Næsset, Erik
Bollandsås, Ole
spellingShingle de Lera Garrido, Ana
Gobakken, Terje
Ørka, Hans
Næsset, Erik
Bollandsås, Ole
Reuse of field data in ALS-assisted forest inventory
Silva Fennica
author_facet de Lera Garrido, Ana
Gobakken, Terje
Ørka, Hans
Næsset, Erik
Bollandsås, Ole
author_sort de Lera Garrido, Ana
title Reuse of field data in ALS-assisted forest inventory
title_short Reuse of field data in ALS-assisted forest inventory
title_full Reuse of field data in ALS-assisted forest inventory
title_fullStr Reuse of field data in ALS-assisted forest inventory
title_full_unstemmed Reuse of field data in ALS-assisted forest inventory
title_sort reuse of field data in als-assisted forest inventory
publisher Finnish Society of Forest Science
series Silva Fennica
issn 2242-4075
publishDate 2020-01-01
description Forest inventories assisted by wall-to-wall airborne laser scanning (ALS), have become common practice in many countries. One major cost component in these inventories is the measurement of field sample plots used for constructing models relating biophysical forest attributes to metrics derived from ALS data. In areas where ALS-assisted forest inventories are planned, and in which the previous inventories were performed with the same method, reusing previously acquired field data can potentially reduce costs, either by (1) temporally transferring previously constructed models or (2) projecting field reference data using growth models that can serve as field reference data for model construction with up-to-date ALS data. In this study, we analyzed these two approaches of reusing field data acquired 15 years prior to the current ALS acquisition to estimate six up-to-date forest attributes (dominant tree height, mean tree height, stem number, stand basal area, volume, and aboveground biomass). Both approaches were evaluated within small stands with sizes of approximately 0.37 ha, assessing differences between estimates and ground reference values. The estimates were also compared to results from an up-to-date forest inventory relying on concurrent field- and ALS data. The results showed that even though the reuse of historical information has some potential and could be beneficial for forest inventories, systematic errors may appear prominent and need to be overcome to use it operationally. Our study showed systematic trends towards the overestimation of lower-range ground references and underestimation of the upper-range ground references.
url https://www.silvafennica.fi/article/10272
work_keys_str_mv AT deleragarridoana reuseoffielddatainalsassistedforestinventory
AT gobakkenterje reuseoffielddatainalsassistedforestinventory
AT ørkahans reuseoffielddatainalsassistedforestinventory
AT næsseterik reuseoffielddatainalsassistedforestinventory
AT bollandsasole reuseoffielddatainalsassistedforestinventory
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