Deriving individual tree competition indices from airborne laser scanning

Pedersen, Rune Østergaard; Bollandsås, Ole Martin; Gobakken, Terje; Næsset, Erik

doi:10.1016/j.foreco.2012.05.043

Cited by 29 publications

(15 citation statements)

References 41 publications

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“…This finding is consistent with those by Tilman (1994) and Pedersen et al (2012) who found that the competition intensity generally decreased with the growth of trees. At the early development stage of oak forests, oak and pine trees had high competition intensities (see Fig.…”

Section: Discussionsupporting

confidence: 93%

Effect of competition on spatial patterns of oak forests on the Chinese Loess Plateau

et al. 2016

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Reforestation or natural forest regeneration is an alternative measure for controlling soil erosion in degraded land on the Chinese Loess Plateau (CLP). However, our understanding of the temporal dynamics and the spatial patterns of forest regeneration remains inadequate. Two oak forests at different development stages were investigated to determine the spatial patterns of competitions (intraspecies and interspecies) during different successional stages. The intraspecies and interspecies spatial relationships among different tree diameters at breast height were analyzed at multiple scales by Kriging interpolation method and univariate and bivariate O-ring statistics. Our analytical results indicated that self-correlation and competition intensity were relatively high between oak and pine trees in the early development stage of oak forests due to their clumped distributions of heavy seeds. Birch trees had a lower competition in comparison to oak trees although birch was the dominant species. Therefore, asymmetric competition of oak trees was most likely to have led to their edge dispersal and their success in replacing the pioneer species. Asymmetric competition means that larger individuals obtained a disproportionately large share of the resources and suppressed the growth of smaller individuals. Kriging interpolation analysis showed a tendency towards homogenization caused by interspecies competition during the succession of oak forests. Our results demonstrated that the competition was the driving factor in the spatial distribution of oak forests on the CLP.

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Section: Discussionsupporting

confidence: 93%

Effect of competition on spatial patterns of oak forests on the Chinese Loess Plateau

et al. 2016

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“…During reforestation or natural forest regeneration, internal competition among plants for limited resources has been proven to be the driving factor for forest succession. The two species were found in a positive self-correlation and high intensity of competition (Li et al, 2008), which is consistent with those by Tilman (1994) andPedersen et al (2012) who found that the competition intensity generally decreased with the growth of trees. Studies of vegetation variation and development have shown that, after herb and shrub communities, Pinus tabulaeformis, as a pioneer species, is generally the first established species and captures resources in disturbance openings (Fan, Guo, Wang, & Duan, 2014).…”

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confidence: 89%

“…Once P. tabulaeformis forests are formed, other, relatively shade-tolerant, species (i.e., Q. wutaishansea) are able to invade (Collins & Carson, 2004). The two species were found in a positive self-correlation and high intensity of competition (Li et al, 2008), which is consistent with those by Tilman (1994) andPedersen et al (2012) who found that the competition intensity generally decreased with the growth of trees.…”

supporting

confidence: 82%

Spatial patterns and interspecific associations among trees at different stand development stages in the natural secondary forests on the Loess Plateau, China

O’Hara

et al. 2019

Ecology and Evolution

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Quercus wutaishansea populations on the Loess Plateau are currently becoming more dominant in natural secondary forests, whereas Pinus tabulaeformis is declining. In the present paper, the diameter class (instead of age) was used to classify the different growth stages as juvenile, subadult, or adult, and the univariate function g(r) was used to analyze the dynamic changes in spatial patterns and interspecific associations in three 1‐ha tree permanent plots on the Loess Plateau, NW China. Our results suggested that the niche breadth changed with the development stage. The diameter distribution curve was consistent with the inverted “J” type, indicating that natural regeneration was common in all three plots. There was a close relationship between the spatial pattern and scale, which showed significant aggregation at small distances, and became more random as distance increased, but in the Pinus + Quercus mixed forests, the whole species were aggregated at distances up to 50 m. The degree of spatial clumping decreased from juvenile to subadult and from subadult to adult. The spatial pattern also differed at different growth stages, likely due to strong intraspecific competition. Associations among different growth stages were positively correlated at small scales. Our study is important to the understanding of the development of the Q. wutaishansea forests; thus, the spatial dynamic change features should be received greater attention when planning forest management and developing restoration strategies on the Loess Plateau.

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“…In inventory practice, many attributes have to be estimated at the tree level in order to be useful. Individual tree coordinates, for instance, are needed for harvesting operations and growth predictions [Pedersen et al, 2012]. ITC approaches are used also in operational urban tree mapping, and monitoring [Holopainen et al, 2013].…”

Section: Introductionmentioning

confidence: 99%

Effects of forest structure and airborne laser scanning point cloud density on 3D delineation of individual tree crowns

Kandare

Ørka

Chan

et al. 2016

European Journal of Remote Sensing

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This paper presents a 3D delineation method for airborne laser scanning point cloud. The method is based on an unsupervised clustering technique applied on horizontal slices followed by vertical merging based on overlapping among clusters. On an Alpine forest dataset, we analysed the effects of different forest structures and point cloud densities on tree crown delineation. Forest structure affects mainly the omission error, which eases with homogeneous tree spacing and sizes, while on the commission error forest structure has only slight effect. Delineation accuracy increases with higher point densities where MannWhitney-Wilcoxon test shows that accuracy differences between thinned data and original data are statistically significant.

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Deriving individual tree competition indices from airborne laser scanning

Cited by 29 publications

References 41 publications

Effect of competition on spatial patterns of oak forests on the Chinese Loess Plateau

Effect of competition on spatial patterns of oak forests on the Chinese Loess Plateau

Spatial patterns and interspecific associations among trees at different stand development stages in the natural secondary forests on the Loess Plateau, China

Effects of forest structure and airborne laser scanning point cloud density on 3D delineation of individual tree crowns

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