Estimating the overstory and understory vertical extents and their leaf area index in intensively managed loblolly pine (Pinus taeda L.) plantations using airborne laser scanning

Leaf area index (LAI) of loblolly pine (Pinus taeda L.) trees of the southern United States varies almost twofold interannually; loblolly pine, essentially, carries two foliage cohorts at peak LAI (September) and one at minimum (MarchApril). Herein, we present an approach that may be site invariant to estimate monthly LAI for loblolly pine using point-in-time measurements from a LI-COR LAI-2000 plant canopy analyzer (PCA). Our analyses used needle accretion and abscission data from monthly needle counts and destructive harvest data from a replicated 2 × 2 factorial experiment of water and nutrition amendments. No significant treatment effects on relative needle accretion or abscission were observed. Cohort (interannual) differences in needle accretion were found but appeared trivial. Cohort year had variable effects on needle abscission. Abscission of current-year foliage began in July and continued through November of the third year; however, only 7%9% remained 23 months following bud initiation. A treatment-invariable regression of PCA measurements on cohort foliage biomass (r2 [Formula: see text] 0.98) was used to estimate annual cohort LAI. We derived monthly estimates of LAI from cohort accretion and abscission and cohort LAI. Monthly estimates of LAI for loblolly pine, using point-in-time measurements from the PCA, appear possible, although further testing is required.

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Application of 3D triangulations of airborne laser scanning data to estimate boreal forest leaf area index

International Journal of Applied Earth Observation and Geoinformation ◽

10.1016/j.jag.2017.02.022 ◽

2017 ◽

Vol 59 ◽

pp. 53-62 ◽

Cited By ~ 3

Author(s):

Titta Majasalmi ◽

Lauri Korhonen ◽

Ilkka Korpela ◽

Jari Vauhkonen

Keyword(s):

Boreal Forest ◽

Leaf Area Index ◽

Leaf Area ◽

Laser Scanning ◽

Airborne Laser Scanning ◽

Area Index ◽

Airborne Laser

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Estimation of leaf area index of Pinus taeda L. and Cupressus lusitanica Mill. by vegetation indices

Scientia Forestalis ◽

10.18671/scifor.v48n125.03 ◽

2020 ◽

Vol 48 (125) ◽

Author(s):

Carla Talita Pertille ◽

Marcos Felipe Nicoletti ◽

Larissa Regina Topanotti ◽

Mario Dobner Júnior

Keyword(s):

Leaf Area Index ◽

Leaf Area ◽

Pinus Taeda ◽

Vegetation Indices ◽

Cupressus Lusitanica ◽

Area Index ◽

Pinus Taeda L

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Validation of an Integrated Estimation of Loblolly Pine (Pinus taeda L.) Leaf Area Index (LAI) Using Two Indirect Optical Methods in the Southeastern United States

Southern Journal of Applied Forestry ◽

10.1093/sjaf/32.3.101 ◽

2008 ◽

Vol 32 (3) ◽

pp. 101-110 ◽

Cited By ~ 11

Author(s):

John S. Iiames ◽

Russell Congalton ◽

Andrew Pilant ◽

Timothy Lewis

Keyword(s):

United States ◽

Leaf Area Index ◽

Leaf Area ◽

Pinus Taeda ◽

Loblolly Pine ◽

Southeastern United States ◽

Area Ratio ◽

Allometric Equations ◽

Area Index ◽

Whole Tree

Abstract Quality assessment of satellite-derived leaf area index (LAI) products requires appropriate ground measurements for validation. Since the National Aeronautics and Space Administration launch of Terra (1999) and Aqua (2001), 1-km, 8-day composited retrievals of LAI have been produced for six biome classes worldwide. The evergreen needle leaf biome has been examined at numerous validation sites, but the dominant commercial species in the southeastern United States, loblolly pine (Pinus taeda), has not been investigated. The objective of this research was to evaluate an in situ optical LAI estimation technique combining measurements from the Tracing Radiation and Architecture of Canopies (TRAC) optical sensor and digital hemispherical photography (DHP) in the southeastern US P.taeda forests. Stand-level LAI estimated from allometric regression equations developed from whole-tree harvest data were compared to TRAC–DHP optical LAI estimates at a study site located in the North Carolina Sandhills Region. Within-shoot clumping, (i.e., the needle-to-shoot area ratio [γE]) was estimated at 1.21 and fell within the range of previously reported values for coniferous species (1.2–2.1). The woody-to-total area ratio (α = 0.31) was within the range of other published results (0.11–0.34). Overall, the indirect optical TRAC–DHP method of determining LAI was similar to LAI estimates that had been derived from allometric equations from whole-tree harvests. The TRAC–DHP yielded a value 0.14 LAI units below that retrieved from stand-level whole-tree harvest allometric equations. DHP alone yielded the best LAI estimate, a 0.04 LAI unit differential compared with the same allometrically derived LAI.

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