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Predicting tree diameter distributions from airborne laser scanning, SPOT 5 satellite, and field sample data in the perm region, Russia / Jussi Peuhkurinen in Forests, vol 9 n° 10 (October 2018)  

Public [article]  inForests > vol 9 n° 10 (October 2018) Titre : Predicting tree diameter distributions from airborne laser scanning, SPOT 5 satellite, and field sample data in the perm region, Russia Type de document : Article/Communication Auteurs : Jussi Peuhkurinen, Auteur ; Timo Tokola, Auteur ; Kseniia Plevak, Auteur ; Sanna Sirparanta, Auteur ; et al., Auteur Année de publication : 2018 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] Abies sibirica [Termes IGN] Alnus incana [Termes IGN] Betula pendula [Termes IGN] classification barycentrique [Termes IGN] diamètre des arbres [Termes IGN] données de terrain [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] image SPOT 5 [Termes IGN] inventaire forestier (techniques et méthodes) [Termes IGN] Picea abies [Termes IGN] Pinus sibirica [Termes IGN] Pinus sylvestris [Termes IGN] placette d'échantillonnage [Termes IGN] Populus tremula [Termes IGN] Russie [Termes IGN] Salix caprea [Termes IGN] Tilia cordata [Vedettes matières IGN] Inventaire forestier Résumé : (Auteur) A tree list is a list of trees in the area of interest containing, for example, the species, diameter, height, and stem volume of each tree. Tree lists can be used to derive various characteristics of the growing stock, and are therefore versatile and informative sources of data for several forest management purposes. Especially in heterogonous and unmanaged forest structures with multiple species, tree list estimates imputed from local reference field data can provide an alternative to mean value estimates of growing stock (e.g., basal area, total stem volume, mean tree diameter, mean tree height, and number of trees). In this study, reference field plots, airborne laser scanning (ALS) data, and SPOT 5 satellite (Satellite Pour l’Observation de la Terre) imagery were used for tree list imputation applying the k most similar neighbors (k-MSN) estimation method in the West Ural taiga region of the Russian Federation for diameter distribution estimation. In k-MSN, weighted average of k field reference plots with highest similarity between field reference plot and target (forest grid cell, or field plot) based on ALS and SPOT 5 features were used to predict the mean values of growing stock and tree lists for the target object simultaneously. Diameter distributions were then constructed from the predicted tree lists. The prediction of mean values and diameter distributions was tested in 18 independent validation plots of 0.25–0.5 ha in size, whose species specific diameter distributions were measured in the field and grouped into three functional groups (Pines, Spruce/Fir, Broadleaf Group), each containing several species. In terms of root mean squared error relative to mean of validation plots, the accuracy of estimation was 0.14 and 0.17 for basal area and total stem volume, respectively. Reynolds error index values and visual inspection showed encouraging results in evaluating the goodness-of-fit statistics of the estimated diameter distributions. Although estimation accuracy was worse for functional group mean values and diameter distributions, the results indicate that it is possible to predict diameter distributions in forests of the test area with the tested methodology and materials. Numéro de notice : A2018-476 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3390/f9100639 Date de publication en ligne : 13/10/2018 En ligne : https://doi.org/10.3390/f9100639 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=91176 [article]

Above-ground and below-ground competition between the willow Salix caprea and its understorey / Ondřej Mudrák in Journal of vegetation science, vol 27 n° 1 (January 2016)  

Public [article]  inJournal of vegetation science > vol 27 n° 1 (January 2016) . - pp 156 - 164 Titre : Above-ground and below-ground competition between the willow Salix caprea and its understorey Type de document : Article/Communication Auteurs : Ondřej Mudrák, Auteur ; Markéta Hermová, Auteur ; Cecilie Tesnerová, Auteur ; Jana Rydlová, Auteur ; Jan Frouz, Auteur Année de publication : 2016 Article en page(s) : pp 156 - 164 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] composition floristique [Termes IGN] mine [Termes IGN] plante herbacée [Termes IGN] République Tchèque [Termes IGN] Salix caprea [Termes IGN] sous-bois [Vedettes matières IGN] Ecologie forestière Résumé : (auteur) Questions : Has the observed decline in the willow Salix caprea L., one of the most common colonizers of post-mining sites in Central Europe, contributed to changes in the rest of the plant community on post-mining sites? How does S. caprea modify its understorey? How is the understorey vegetation affected by above-ground and below-ground competition with S. caprea? Location : Heaps after coal mining near Sokolov, Czech Republic (50°14′21″ N, 12°40′45″ E). Methods : The effects of above-ground and below-ground competition with the willow S. caprea on its understorey plant community were studied in un-reclaimed post-mining sites. Below-ground competition was evaluated by comparing (1) frames inserted into the soil that excluded woody roots (frame treatment), (2) frames that initially excluded woody root growth but then allowed regrowth of the roots (open-frame treatment), and (3) undisturbed soil (no-frame treatment). These treatments were combined with S. caprea thinning to assess the effect of above-ground competition. Results : Three years after the start of the experiment, above-ground competition from S. caprea (as modified by thinning of the S. caprea canopy) had not affected understorey biomass or species number, but had affected species composition. In contrast, below-ground competition significantly affected both the above-ground and below-ground biomass of the understorey. The above-ground biomass of the understorey was larger in the frame treatment (which excluded woody roots) than in the other two treatments. The below-ground biomass of the understorey was larger in the frame than in the open-frame treatment. Unlike above-ground competition (light availability), below-ground competition did not affect understorey species composition. Conclusions : Our results suggest that S. caprea is an important component during plant succession on post-mining sites because it considerably modifies its understorey plant community. Below-ground competition is a major reason for the low cover and biomass of the herbaceous understorey in S. caprea stands on post-mining sites. Numéro de notice : A2016-362 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Article DOI : 10.1111/jvs.12330 En ligne : http://dx.doi.org/10.1111/jvs.12330 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=81099 [article]