Spatially explicit characterization of boreal forest gap dynamics using multi-temporal lidar data

Vepakomma, Udayalakshmi; St-Onge, Benoît; Kneeshaw, Daniel

doi:10.1016/j.rse.2007.10.001

Cited by 155 publications

(145 citation statements)

References 45 publications

Supporting

Mentioning

127

Contrasting

Unclassified

Order By: Relevance

“…Our results are slightly less accurate compared to the studies by Gaulton and Malthus (2010) who reported an overall accuracy of 88% in Picea sitchensis plantation in the UK and Vepakomma et al (2008) with an accuracy of 96% in mature forests in Canada. Both studies were carried out in managed forests with a relatively flat terrain and the canopy gaps are caused by different disturbance agents such as forest fires, spruce budworm outbreaks, wind-throw, and tree-falls.…”

Section: Discussioncontrasting

confidence: 98%

“…To identify forest canopy gaps, we used gap indicator function G for a given cell at (x, y) on the CHM (Vepakomma et al, 2008) defined as (Eq. 7.1):…”

Section: Analyzing Forest Canopy Gaps Induced By Landslidesmentioning

confidence: 99%

“…Blackburn and Milton (1996) defined forest gaps in remote sensing imagery as an open space between high canopies, and above the low vegetation. Forest canopy gaps can also be defined in the context of small scale forest disturbances, as holes or opening in the forest canopy at a certain height, due to fall or death of one or more trees (Vepakomma et al, 2008;Frolking et al, 2009). Gaps are often defined either from field measurement or from remote sensing imagery (Broadbent et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

“…Gaps are often defined either from field measurement or from remote sensing imagery (Broadbent et al, 2008). In practice, ground measurements are costly and time consuming, and the interpretation of spectral remote sensing imagery may be hampered by shadows, lack of contrast, or varying sun incidence angles (Runkle, 1991;Fox et al, 2000;Vepakomma et al, 2008;Koukoulas and Blackburn, 2004). Koukoulas and Blackburn (2004) developed a method to detect gap features in a broad leaved deciduous forest, using an ALS-derived canopy height model (CHM).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Airborne laser scanning : for forested landslides investigation in temperate and tropical invironments

Razak¹

View full text Add to dashboard Cite

Section: Discussioncontrasting

confidence: 98%

“…To identify forest canopy gaps, we used gap indicator function G for a given cell at (x, y) on the CHM (Vepakomma et al, 2008) defined as (Eq. 7.1):…”

Section: Analyzing Forest Canopy Gaps Induced By Landslidesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Airborne laser scanning : for forested landslides investigation in temperate and tropical invironments

Razak¹

View full text Add to dashboard Cite

“…Provided that an accurate digital terrain model (DTM) exists, canopy height models, which have become popular for disturbance analysis by means of canopy gaps or canopy height profiles (Fujita et al 2003, Henbo et al 2004, Vepakomma et al 2010, could be calculated by subtracting the terrain model from the surface model , Vepakomma et al 2008. However, for our study area in the Ukraine, as well as for many other countries, accurate DTMs are lacking.…”

Section: Canopy Gap Assessment Using High-resolution Stereo Satellitementioning

confidence: 99%

Gap pattern of the largest primeval beech forest of Europe revealed by remote sensing

et al. 2015

View full text Add to dashboard Cite

Abstract. Little is known about the gap pattern of primeval beech forests, since large-scale studies with continuous coverage are lacking. Analyses of forest structural patterns have benefitted from advances in remote sensing, especially with the launch of satellites providing data of submetric ground resolution. These developments can strongly advance our knowledge of natural forest dynamics and disturbance regimes. The Uholka-Shyrokyi Luh forest in the Ukrainian Carpathians, the largest remnant of primeval European beech (Fagus sylvatica L.) covering 102.8 km 2 , is an outstanding object to analyze the frequency distribution of gap sizes and to infer processes of forest dynamics. A stereo pair of very high-resolution WorldView-2 satellite images was used to characterize the forest's gap pattern. Canopy gaps were first digitized stereoscopically based on the image pair. In a second step, spectral properties in the red and yellow frequency bands were used to distinguish the stereoscopically mapped gap areas from non-gap areas, which enabled gap mapping over the entire study area. To validate the spectral gap mapping 338 randomly distributed samples were assigned manually to gap and non-gap areas based on the orthoimages. We found excellent agreement except for an overestimation of gaps close to clouds due to diffuse image areas. The frequency distribution of gap size revealed the forest to be structured by a small-scale mosaic of gaps mainly ,200 m 2 (98% of the gaps). Only a few large, stand-replacing events were detected, most probably caused by a wind storm in March 2007 and a heavy wet snow fall in October 2009. The small canopy gaps reflect fine-scale processes shaping forest structure, i.e., the death of single trees or groups of a few trees and is in line with the findings of the terrestrial forest inventory. We conclude that remote sensing approaches based on very high-resolution satellite images are highly useful to characterize even small-scale forest disturbance regimes and to study long-term gap dynamics. Stereo satellite images provide two viewing angles of the study area, thus allowing for a highly accurate mapping of canopy gaps in forests with a complex topography.

show abstract

Integrating LIDAR‐derived canopy structure into cerulean warbler habitat models

2015

View full text Add to dashboard Cite

Researchers have suggested that the cerulean warbler (Setophaga cerulea), a declining species, settles on its breeding grounds in response to a particular canopy structure within mature deciduous forests. Conservation management strategies could be more effective if this association was further clarified; however, defining canopy structure from the ground can be laborious and subjective. We used light detection and ranging (LIDAR) data to create canopy height models that provide accurate objective data on the vertical and horizontal canopy structure throughout the extent of our study area in south-central Indiana's Morgan-Monroe and Yellowwood state forests. In addition, we used LIDAR data to construct digital terrain models to derive topographic metrics for our study area. We combined these data with data from ground-level surveys and created habitat models to determine which variables best predict cerulean warbler occurrence and density. Model subsets containing only LIDAR-derived variables performed better than model subsets containing variables derived only from ground-level surveys. The top occurrence model indicated that cerulean warblers defended areas that were associated with northeast facing slopes, lower elevations, gentler slopes, and greater hickory (Carya spp.) basal area (m 2 /ha). The top density models indicated that the highuse areas for cerulean warblers were associated with steeper slopes, lower total basal area (m 2 /ha), fewer large trees (!53 cm diameter at breast height), greater white oak (Quercus alba) basal area (m 2 /ha), and contained a homogeneous horizontal and vertical canopy structure. Conservation managers should consider silvicultural practices that promote old growth oak-hickory (Quercus spp.-Carya spp.) forests on mesic slopes. Furthermore, LIDAR can provide an objective and efficient method for collecting terrain and surface data at large scales, which can be used to define habitat and aid conservation efforts. Ó 2015 The Wildlife Society.

show abstract

Spatially explicit characterization of boreal forest gap dynamics using multi-temporal lidar data

Cited by 155 publications

References 45 publications

Airborne laser scanning : for forested landslides investigation in temperate and tropical invironments

Airborne laser scanning : for forested landslides investigation in temperate and tropical invironments

Gap pattern of the largest primeval beech forest of Europe revealed by remote sensing

Integrating LIDAR‐derived canopy structure into cerulean warbler habitat models

Contact Info

Product

Resources

About