Beckschäfer, Philip

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","iForest - Biogeosciences and Forestry"],["dc.bibliographiccitation.lastpage","11"],["dc.bibliographiccitation.volume","7"],["dc.contributor.author","Beckschäfer, Philip"],["dc.contributor.author","Fehrmann, Lutz"],["dc.contributor.author","Harrison, Rhett D."],["dc.contributor.author","Xu, Jianchu"],["dc.contributor.author","Kleinn, Christoph"],["dc.date.accessioned","2017-09-07T11:47:03Z"],["dc.date.available","2017-09-07T11:47:03Z"],["dc.date.issued","2013"],["dc.description.abstract","Canopy leaf area, frequently quantified by the Leaf Area Index (LAI), serves as the dominant control over primary production, energy exchange, transpiration, and other physiological attributes related to ecosystem processes. Maps depicting the spatial distribution of LAI across the landscape are of particularly high value for a better understanding of ecosystem dynamics and processes, especially over large and remote areas. Moreover, LAI maps have the potential to be used by process models describing energy and mass exchanges in the biosphere/atmosphere system. In this article we assess the applicability of the RapidEye satellite system, whose sensor is optimized towards vegetation analyses, for mapping LAI along a disturbance gradient, ranging from heavily disturbed shrub land to mature mountain rainforest. By incorporating image texture features into the analysis, we aim at assessing the potential quality improvement of LAI maps and the reduction of uncertainties associated with LAI maps compared to maps based on Vegetation Indexes (VI) solely. We identified 22 out of the 59 image features as being relevant for predicting LAI. Among these, especially VIs were ranked high. In particular, the two VIs using RapidEye’s RED-EDGE band stand out as the top two predictor variables. Nevertheless, map accuracy as quantified by the mean absolute error obtained from a 10-fold cross validation (MAE_CV) increased significantly if VIs and texture features are combined (MAE_CV = 0.56), compared to maps based on VIs only (MAE_CV = 0.62). We placed special emphasis on the uncertainties associated with the resulting map addressing that map users often treat uncertainty statements only in a pro-forma manner. Therefore, the LAI map was complemented with a map depicting the spatial distribution of the goodness-of-fit of the model, quantified by the mean absolute error (MAE), used for predictive mapping. From this an area weighted MAE (= 0.35) was calculated and compared to the unweighted MAE of 0.29. Mapping was done using randomForest, a widely used statistical modeling technique for predictive biological mapping."],["dc.identifier.doi","10.3832/ifor0968-006"],["dc.identifier.gro","3149244"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/5900"],["dc.language.iso","en"],["dc.notes.intern","Kleinn Crossref Import"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.relation.issn","1971-7458"],["dc.title","Mapping Leaf Area Index in subtropical upland ecosystems using RapidEye imagery and the randomForest algorithm"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","410"],["dc.bibliographiccitation.journal","Ecological Indicators"],["dc.bibliographiccitation.lastpage","425"],["dc.bibliographiccitation.volume","102"],["dc.contributor.author","Kukunda, Collins B."],["dc.contributor.author","Beckschäfer, Philip"],["dc.contributor.author","Magdon, Paul"],["dc.contributor.author","Schall, Peter"],["dc.contributor.author","Wirth, Christian"],["dc.contributor.author","Kleinn, Christoph"],["dc.date.accessioned","2020-11-05T14:56:53Z"],["dc.date.available","2020-11-05T14:56:53Z"],["dc.date.issued","2019"],["dc.identifier.doi","10.1016/j.ecolind.2019.02.056"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/68383"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-352.4"],["dc.relation.issn","1470-160X"],["dc.title","Scale-guided mapping of forest stand structural heterogeneity from airborne LiDAR"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Scientific Reports"],["dc.bibliographiccitation.volume","7"],["dc.contributor.author","Liu, X. W."],["dc.contributor.author","Chesters, D."],["dc.contributor.author","Dai, Q. Y."],["dc.contributor.author","Niu, Z. Q."],["dc.contributor.author","Beckschäfer, P."],["dc.contributor.author","Martin, K."],["dc.contributor.author","Zhu, C. D."],["dc.date.accessioned","2020-12-10T18:10:06Z"],["dc.date.available","2020-12-10T18:10:06Z"],["dc.date.issued","2017"],["dc.identifier.doi","10.1038/s41598-017-05262-8"],["dc.identifier.eissn","2045-2322"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/73849"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Integrative Profiling of Bee Communities from Habitats of Tropical Southern Yunnan (China)"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","228"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","iForest - Biogeosciences and Forestry"],["dc.bibliographiccitation.lastpage","237"],["dc.bibliographiccitation.volume","6"],["dc.contributor.author","Beckschäfer, Philip"],["dc.contributor.author","Seidel, Dominik"],["dc.contributor.author","Kleinn, Christoph"],["dc.contributor.author","Xu, Jianchu"],["dc.date.accessioned","2017-09-07T11:47:10Z"],["dc.date.available","2017-09-07T11:47:10Z"],["dc.date.issued","2013"],["dc.description.abstract","At least 10 different methods to determine exposure for hemispherical photographs were used by scientists in the last two decades, severely hampering comparability among studies. Here, an overview of the applied methods is reported. For the standardization of photographic exposure, a time-consuming reference measurement in the open land towards the unobstructed sky was required so far. The two Histogram Methods proposed here make use of the technical advances of digital cameras which enable users to assess a photograph’s histogram directly at the location of measurement. This avoids errors occurring due to variations in sky lighting happening in the time span between taking the reference measurement and reaching the sample location within the forest. The Histogram Methods speed up and simplify taking hemispherical photographs, and introduce an objectively applicable, standardized approach. We highlight the importance of correct exposure by quantifying the overestimation of gap fraction resulting from auto-exposed photographs under a wide range of canopy openness situations. In our study, gap fraction derived from auto-exposed photographs reached values up to 900% higher than those derived from non-overexposed photographs. By investigating the size of the largest gap per photograph and the number of small gaps (gaps contributing less than 0.1% to gap fraction), we concluded that the overestimation of gap fraction resulted mainly from the overexposure of vegetation surrounding large gaps."],["dc.identifier.doi","10.3832/ifor0957-006"],["dc.identifier.gro","3149269"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/5927"],["dc.language.iso","en"],["dc.notes.intern","Kleinn Crossref Import"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.relation.issn","1971-7458"],["dc.title","On the exposure of hemispherical photographs in forests"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","iForest - Biogeosciences and Forestry"],["dc.bibliographiccitation.lastpage","5"],["dc.bibliographiccitation.volume","8"],["dc.contributor.author","Nölke, Nils"],["dc.contributor.author","Beckschäfer, Philip"],["dc.contributor.author","Kleinn, Christoph"],["dc.date.accessioned","2017-09-07T11:47:05Z"],["dc.date.available","2017-09-07T11:47:05Z"],["dc.date.issued","2014"],["dc.identifier.doi","10.3832/ifor1129-007"],["dc.identifier.gro","3149254"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/5911"],["dc.notes.intern","Kleinn Crossref Import"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.publisher","Italian Society of Sivilculture and Forest Ecology (SISEF)"],["dc.relation.issn","1971-7458"],["dc.title","Thermal canopy photography in forestry - an alternative to optical cover photography"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","617"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","International Journal of Biometeorology"],["dc.bibliographiccitation.lastpage","625"],["dc.bibliographiccitation.volume","63"],["dc.contributor.author","Liyanage, K.K."],["dc.contributor.author","Khan, Sehroon"],["dc.contributor.author","Ranjitkar, Sailesh"],["dc.contributor.author","Yu, Haiying"],["dc.contributor.author","Xu, Jianchu"],["dc.contributor.author","Brooks, Siraprapa"],["dc.contributor.author","Beckschäfer, Philip"],["dc.contributor.author","Hyde, Kevin D."],["dc.date.accessioned","2020-12-10T14:10:48Z"],["dc.date.available","2020-12-10T14:10:48Z"],["dc.date.issued","2018"],["dc.identifier.doi","10.1007/s00484-018-1598-z"],["dc.identifier.eissn","1432-1254"],["dc.identifier.issn","0020-7128"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/70883"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Evaluation of key meteorological determinants of wintering and flowering patterns of five rubber clones in Xishuangbanna, Yunnan, China"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","84"],["dc.bibliographiccitation.journal","Forest Ecology and Management"],["dc.bibliographiccitation.lastpage","99"],["dc.bibliographiccitation.volume","404"],["dc.contributor.author","Yang, Xueqing"],["dc.contributor.author","Blagodatsky, Sergey"],["dc.contributor.author","Liu, Feng"],["dc.contributor.author","Beckschäfer, Philip"],["dc.contributor.author","Xu, Jianchu"],["dc.contributor.author","Cadisch, Georg"],["dc.date.accessioned","2020-12-10T14:24:05Z"],["dc.date.available","2020-12-10T14:24:05Z"],["dc.date.issued","2017"],["dc.identifier.doi","10.1016/j.foreco.2017.08.013"],["dc.identifier.issn","0378-1127"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/72133"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Rubber tree allometry, biomass partitioning and carbon stocks in mountainous landscapes of sub-tropical China"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]