The analysis of the consequences of land use （in particular forest use） may be considered as a partial step towards an integrated modeling of a land system. In the paper a forest territory is considered, where a gap...The analysis of the consequences of land use （in particular forest use） may be considered as a partial step towards an integrated modeling of a land system. In the paper a forest territory is considered, where a gapcut is made, and after a given time period the eventual change in the spatial distribution of undergrowth plants and tree seedlingsis to be detected. Floristic data are collected along a line transect. A method for the detection of the change in the plant distributions along the transect is proposed to see whether this occurs at the geometric frontier of the human intervention. Since in the considered case the distribution of the changepoint estimate is not known, as a substitute of its confidence interval, the socalled changeinterval is calcu lated, using an adaptation of the bootstrap method. As an illustration, for a concrete plant species, the maximum likelihood estimation of the changepoint and the calcu lation of the above mentioned changeinterval is presented. Finally, the validation of the proposed method against some typical ecological situations is also presented, which provides a justification of the used algorithms.展开更多
文摘The analysis of the consequences of land use （in particular forest use） may be considered as a partial step towards an integrated modeling of a land system. In the paper a forest territory is considered, where a gapcut is made, and after a given time period the eventual change in the spatial distribution of undergrowth plants and tree seedlingsis to be detected. Floristic data are collected along a line transect. A method for the detection of the change in the plant distributions along the transect is proposed to see whether this occurs at the geometric frontier of the human intervention. Since in the considered case the distribution of the changepoint estimate is not known, as a substitute of its confidence interval, the socalled changeinterval is calcu lated, using an adaptation of the bootstrap method. As an illustration, for a concrete plant species, the maximum likelihood estimation of the changepoint and the calcu lation of the above mentioned changeinterval is presented. Finally, the validation of the proposed method against some typical ecological situations is also presented, which provides a justification of the used algorithms.
