Saborowski, Joachim

[["dc.bibliographiccitation.journal","Tagung (Deutscher Verband Forstlicher Forschungsanstalten, Sektion Forstliche Biometrie und Informatik)"],["dc.contributor.author","Nothdurft, Arne"],["dc.contributor.author","Hradetzky, J."],["dc.contributor.author","Schöpfer, W."],["dc.contributor.author","Saborowski, Joachim"],["dc.contributor.author","Nuske, Robert S."],["dc.date.accessioned","2020-12-08T08:29:52Z"],["dc.date.available","2020-12-08T08:29:52Z"],["dc.date.issued","2009"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/69472"],["dc.relation.orgunit","Abteilung Ökosystemmodellierung"],["dc.title","Dichteschätzung für N-Baum-Stichproben durch Reproduktion von Baumartenverteilungsmustern"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","953"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Canadian Journal of Forest Research"],["dc.bibliographiccitation.lastpage","967"],["dc.bibliographiccitation.volume","40"],["dc.contributor.author","Nothdurft, Arne"],["dc.contributor.author","Saborowski, Joachim"],["dc.contributor.author","Nuske, Robert S."],["dc.contributor.author","Stoyan, Dietrich"],["dc.date.accessioned","2018-11-07T08:43:25Z"],["dc.date.available","2018-11-07T08:43:25Z"],["dc.date.issued","2010"],["dc.description.abstract","In k-tree sampling, also referred to as point-to-tree distance sampling, the k nearest trees are measured. The problem associated with k-tree sampling is its lack of unbiased density estimators. The presented density estimator based on point pattern reconstruction remedies that shortcoming. It requires the coordinates of all k trees. These coordinates are translated into a simulation window where they remain unchanged. Empirical cumulative distribution functions of intertree and location-to-tree distances estimated from the sample plots are set as target characteristics. Using the idea of simulated annealing, an optimal new tree pattern is constructed in the simulation window outside the k-tree samples. The reconstruction of the point pattern minimizes the contrast between the empirical cumulative distribution functions and their analogs for the simulated pattern. The density estimator is simply the tree density of the optimum pattern in the simulation window. The performance of the reconstruction-based density estimator is assessed for k = 6 and k = 4 based on systematic sampling grids regarding its potential application in forest inventories. Simulations are carried out using real stem maps (covering different stand densities and different types of spatial point patterns, such as regular, clustered, and random) as well as completely random patterns. The new density estimator proves to be empirically superior in terms of bias and root mean squared error compared with commonly used estimators. The reconstruction-based density estimator has biases smaller than 2%."],["dc.description.abstract","En chantillonnage de k arbres, aussi appel chantillonnage de k arbres selon leur distance, on mesure les k arbres les plus proches. Le problme li lchantillonnage de k arbres est son incapacit fournir des estimateurs de densit sans biais. Lestimateur de densit bas sur la reconstruction du patron des points comble cette lacune. Il requiert les coordonnes de tous les k arbres. Ces coordonnes sont traduites dans une fentre de simulation o elles demeurent inchanges. Les fonctions empiriques de distribution cumulative de distances entre les arbres et entre un point et les arbres estimes partir des placettes chantillons sont les caractristiques cibles. En utilisant le recuit simul, un nouveau patron optimal des arbres est construit dans la fentre de simulation en dehors des k arbres chantillons. La reconstruction du patron de points minimise le contraste entre les fonctions empiriques et leurs analogues drivs du patron simul. Lestimateur de densit est tout simplement la densit des arbres de la structure optimale dans la fentre de simulation. La performance de lestimateur de densit bas sur la reconstruction est value pour k = 6 et k = 4 sur la base des grilles dchantillonnage systmatique quant son application potentielle dans les inventaires forestiers. Des simulations sont effectues en utilisant les cartes relles des tiges (couvrant diffrentes densits de peuplement et diffrents types de patrons spatiaux de points, tels que rgulier, en grappe et alatoire) aussi bien que des patrons compltement alatoires. Le nouvel estimateur de densit savre empiriquement suprieur en termes de biais et derreur quadratique moyenne par rapport aux estimateurs frquemment utiliss. Son biais est infrieur 2%."],["dc.identifier.doi","10.1139/X10-046"],["dc.identifier.isi","000277602400011"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/19960"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","0045-5067"],["dc.relation.orgunit","Abteilung Ökosystemmodellierung"],["dc.title","Density estimation based on k-tree sampling and point pattern reconstruction"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.journal","Allgemeine Forst- und Jagdzeitung"],["dc.bibliographiccitation.lastpage","13"],["dc.bibliographiccitation.volume","187"],["dc.contributor.author","Schoneberg, S."],["dc.contributor.author","Nothdurft, A."],["dc.contributor.author","Nuske, Robert S."],["dc.contributor.author","Ackermann, J."],["dc.contributor.author","Nagel, J."],["dc.contributor.author","Saborowski, Joachim"],["dc.date.accessioned","2020-12-08T08:44:34Z"],["dc.date.available","2020-12-08T08:44:34Z"],["dc.date.issued","2016"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/69476"],["dc.relation.orgunit","Abteilung Ökosystemmodellierung"],["dc.title","Comparison of stand volume predictions based on airborne laser scanning data versus digital color infrared images"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","1-2"],["dc.bibliographiccitation.journal","ALLGEMEINE FORST UND JAGDZEITUNG"],["dc.bibliographiccitation.lastpage","13"],["dc.bibliographiccitation.volume","187"],["dc.contributor.author","Schoneberg, Sebastian"],["dc.contributor.author","Nothdurft, Arne"],["dc.contributor.author","Nuske, Robert S."],["dc.contributor.author","Ackermann, Joerg"],["dc.contributor.author","Saborowski, Joachim"],["dc.date.accessioned","2018-11-07T10:20:29Z"],["dc.date.available","2018-11-07T10:20:29Z"],["dc.date.issued","2016"],["dc.description.abstract","Practical forest management requires information on dendrometrical forest parameters in a high spatial resolution, particularly interesting is the timber volume. Nearest neighbor techniques and the random forest approach were employed in this study to predict timber volume per hectare (total stem volume and stem volume of large beech trees, DBH >= 60 cm) at forest stand level. The predictions were based on sample plot data from a regional forest inventory and selected sets of auxiliary variables derived from two different remote sensing data sources airborne laser scanning (ALS) data and aerial stereo images (ASI) to quantify and compare prediction precision. Existing studies conclude that ALS data provide more precise height information, but also that acquisition of ALS data is more expensive than of ASI data, which are often already available from other monitoring projects. Currently the cost of ASI data is about a half to a third of ALS data. To make spatial predictions we compared two frequently used methods for imputation: random forest and k-most similar neighbors. For both methods, the prediction precisions (RMSE) were similar. Most promising was the fact that the two different sources of auxiliary variables resulted in predictions of almost the same precision. The similarity between ASI and ALS predictions suggest that ASI may serve as a lower-cost alternative to ALS data for estimating many forest stand-level variables."],["dc.identifier.isi","000375351700001"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/41899"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","J D Sauerlaenders Verlag"],["dc.relation.issn","0002-5852"],["dc.title","Comparison of stand volume predictions based on airborne laser scanning data versus aerial stereo images"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","30"],["dc.bibliographiccitation.journal","Ecological Modelling"],["dc.bibliographiccitation.lastpage","47"],["dc.bibliographiccitation.volume","346"],["dc.contributor.author","Thiele, Jan Christoph"],["dc.contributor.author","Nuske, Robert S."],["dc.contributor.author","Ahrends, Bernd"],["dc.contributor.author","Panferov, Oleg"],["dc.contributor.author","Albert, Matthias"],["dc.contributor.author","Staupendahl, Kai"],["dc.contributor.author","Junghans, Udo"],["dc.contributor.author","Jansen, Martin"],["dc.contributor.author","Saborowski, Joachim"],["dc.date.accessioned","2018-11-07T10:27:13Z"],["dc.date.available","2018-11-07T10:27:13Z"],["dc.date.issued","2017"],["dc.description.abstract","Projected climate change implies that site conditions can no longer be expected to remain constant over a tree's lifetime. The fast and complex changes in site characteristics and growth patterns diminish the value of traditional knowledge and profoundly alter the conditions of forest management. One way to tackle the inherent uncertainties are simulation studies addressing these new dynamics and mechanisms. The aim of this study is to present such a simulation model system comprising various established and validated process-based and statistical models assessing the complex and dynamic response of a forest stand to climate change. For a given climate scenario, these coupled models estimate the potential growth and yield and various risks considering changing site and stand conditions. As an example, the model system is applied to managed forest stands of Norway spruce (Picea abies (L) H. Karst.) in a forest district located in central western Germany. For the changing climate conditions according to SRES B1 and A1 B, the model results suggest a positive effect on the site index and, by contrast, a negative impact on tree survival of increasing risks regarding drought stress mortality, wind damage, and bark beetle infestation given the climate change scenario. The annual contribution margin of timber production under consideration of damage risks by drought stress mortality, wind, and bark beetle infestation reveals that, in this case, the increased growth is able to compensate for the higher risks with few exceptions. Furthermore, we discuss the advantages and challenges of employing a dynamic complex simulation model system for climate change impact assessment based on high-resolution climate data. (C) 2016 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.ecolmodel.2016.11.013"],["dc.identifier.isi","000393248900004"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/43203"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","1872-7026"],["dc.relation.issn","0304-3800"],["dc.relation.orgunit","Abteilung Ökoinformatik, Biometrie und Waldwachstum"],["dc.title","Climate change impact assessment-A simulation experiment with Norway spruce for a forest district in Central Europe"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","303"],["dc.bibliographiccitation.lastpage","310"],["dc.contributor.author","Thiele, Jan Christoph"],["dc.contributor.author","Nuske, Robert S."],["dc.contributor.author","Ahrends, B."],["dc.contributor.author","Saborowski, J."],["dc.contributor.editor","Mahammadzadeh, M."],["dc.contributor.editor","Biebeler, H."],["dc.contributor.editor","Bardt, H."],["dc.date.accessioned","2020-12-08T08:44:40Z"],["dc.date.available","2020-12-08T08:44:40Z"],["dc.date.issued","2009"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/69478"],["dc.publisher","Institut der deutschen Wirtschaft Köln Medien GmbH"],["dc.relation.ispartof","Klimaschutz und Anpassung an die Klimafolgen"],["dc.relation.orgunit","Abteilung Ökosystemmodellierung"],["dc.title","Entwicklung eines Entscheidungsunterstützungssystems für die Waldbewirtschaftung unter sich ändernden Klimabedingungen"],["dc.type","book_chapter"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","107"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Forest Ecology and Management"],["dc.bibliographiccitation.lastpage","116"],["dc.bibliographiccitation.volume","259"],["dc.contributor.author","Nuske, Robert S."],["dc.contributor.author","Sprauer, Susanne"],["dc.contributor.author","Saborowski, Joachim"],["dc.date.accessioned","2020-12-07T10:53:20Z"],["dc.date.available","2020-12-07T10:53:20Z"],["dc.date.issued","2009"],["dc.description.abstract","Forestry around the world has been experiencing a paradigm shift towards more nature-oriented forest management leading foresters to emulate natural disturbances by their silvicultural treatments. Important characteristics of all disturbances are their size, severity, temporal and spatial distribution. This study focuses on the spatial distribution of gaps in the forest canopy which are typically caused by small-scale, low intensity disturbances. The considerable spatial extent and irregular shape of canopy gaps are obvious obstacles to the application of classical point pattern analysis. The approximation of objects by their centroids does not lead to reasonable results, since the objects are at the same scale as the expected effects. By dividing the study area in grid cells and analysing all cells covered by an object, the size and the shape of the objects is accounted for. Nevertheless, both methods show undesirable effects. Thus we propose a new approach using the boundary polygons of the objects and construct the adapted pair-correlation function from the shortest distances between polygons. The adapted pair-correlation function is presented using simulated data and mapped canopy gaps of a near natural forest reserve. The results of our proposed method are compared to the grid-based approach and the classical point pattern analysis. The presented method provides meaningful results and even reveals the relationship of objects at short distances, which is not possible using the classical point pattern analysis or the grid-based approach. With regard to the analysis of the spatial distribution of canopy gaps, the adapted pair-correlation function proves to be a useful analytical tool."],["dc.identifier.doi","10.1016/j.foreco.2009.09.050"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/69431"],["dc.language.iso","en"],["dc.relation.issn","0378-1127"],["dc.relation.orgunit","Abteilung Ökosystemmodellierung"],["dc.subject.gro","Canopy gaps"],["dc.subject.gro","Disturbances"],["dc.subject.gro","Pair-correlation function"],["dc.subject.gro","Point pattern"],["dc.subject.gro","Spatial statistics"],["dc.title","Adapting the pair-correlation function for analysing the spatial distribution of canopy gaps"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]