检索结果-南通市图书馆

Why ecosystem characteristics predicted from remotely sensed data are unbiased and biased at the same time-and how this affects applications

引用

Forest Ecosystems 2024年第1期11卷 24-31页

作者： Goran Ståhl terje gobakken Svetlana Saarela Henrik J.Persson Magnus Ekstrom Sean P.Healey Zhiqiang Yang Johan Holmgren Eva Lindberg Kenneth Nystrom Emanuele Papucci Patrik Ulvdal Hans OleØrka Erik Næsset Zhengyang Hou Håkan Olsson Ronald E.McRoberts Department of Forest Resource Management Swedish University of Agricultural Sciences90183UmeåSweden Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life SciencesÅsNorway USDA Forest Service Rocky Mountain Research StationOgdenUTUSA The Key Laboratory for Silviculture and Conservation of Ministry of Education Beijing Forestry UniversityBeijing100083China Department of Forest Resources University of MinnesotaSt.PaulMNUSA

Remotely sensed data are frequently used for predicting and mapping ecosystem characteristics,and spatially explicit wall-to-wall information is sometimes proposed as the best possible source of information for ***,wall-to-wall information typically relies on model-based prediction,and several features of model-based prediction should be understood before extensively relying on this type of *** such feature is that model-based predictors can be considered both unbiased and biased at the same time,which has important implications in several areas of *** this discussion paper,we first describe the conventional model-unbiasedness paradigm that underpins most prediction techniques using remotely sensed(or other)auxiliary *** this point of view,model-based predictors are typically ***,we show that for specific domains,identified based on their true values,the same model-based predictors can be considered biased,and sometimes severely *** suggest distinguishing between conventional model-bias,defined in the statistical literature as the difference between the expected value of a predictor and the expected value of the quantity being predicted,and design-bias of model-based estimators,defined as the difference between the expected value of a model-based estimator and the true value of the quantity being *** show that model-based estimators(or predictors)are typically design-biased,and that there is a trend in the design-bias from overestimating small true values to underestimating large true ***,we give examples of applications where this is important to acknowledge and to potentially make adjustments to correct for the design-bias *** argue that relying entirely on conventional model-unbiasedness may lead to mistakes in several areas of application that use predictions from remotely sensed data.

关键词： Bias Model-based inference Design-based inference

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Benefits of past inventory data as prior information for the current inventory

引用

Forest Ecosystems 2020年第2期7卷 263-273页

作者： Annika Kangas terje gobakken Erik Næsset Bioeconomy and Environment Natural Resources Institute Luke(Finland)Yliopistokatu 680100 JoensuuFinland Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life SciencesP.O.Box 5003NO-1432ÅsNorway.

Background:When auxiliary information in the form of airborne laser scanning(ALS)is used to assist in estimating the population parameters of interest,the benefits of prior information from previous inventories are not *** a simulation study,we compared three different approaches:1)using only current data,2)using nonupdated old data and current data in a composite estimator and 3)using updated old data and current data with a Kalman *** also tested three different estimators,namely i)Horwitz-Thompson for a case of no auxiliary information,ii)model-assisted estimation and iii)model-based *** compared these methods in terms of bias,precision and accuracy,as estimators utilizing prior information are not guaranteed to be ***:The largest standard errors were obtained when neither prior information nor auxiliary information were *** a growth model was not applied to update the old data,the resulting composite estimators were *** RMSEs were obtained using non-updated prior information in a composite *** the ALS data as auxiliary information produced smaller RMSE than using prior information from the old *** smallest RMSEs were obtained when both the auxiliary data and updated old data were *** growth updating the bias can be substantially reduced,although design-unbiasedness of the estimator cannot be ***:Prior information from old inventory data can be useful also when combined with highly accurate auxiliary information,when both data sources are efficiently *** benefits obtained from using the old data will increase if the past harvests can be detected without errors from changes in the auxiliary data instead of being predicted with models.

关键词： Data fusion Kalman filtering

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Detecting the presence of natural forests using airborne laser scanning data

引用

Forest Ecosystems 2023年第6期10卷 668-680页

作者： Marie-Claude Jutras-Perreault terje gobakken Erik Næsset Hans OleØrka Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life SciencesNMBUP.O.BoxNO-1432ÅsNorway

Centuries of forest exploitation have caused significant loss of natural forests in Europe,leading to a decline in populations for many *** prevent further loss in biodiversity,the Norwegian government has set a target of protecting 10%of the forested ***,recent data from the National Forest Inventory(NFI)reveals that less than 2%of Norway's forested area consists of natural *** identify forests with high conservation value,we used vertical and horizontal variables derived from airborne laser scanning(ALS)data,along with NFI plot *** study aimed to predict the presence of natural forests across three counties in southeastern Norway,using three different definitions:pristine,near-natural,and semi-natural *** forests are scarce,and their underrepresentation in field reference data can compromise the accuracy of the *** address this,we assessed the potential gain of including additional field data specifically targeting natural forests to achieve a better balance in the ***,we examined the impact of stratifying the data by dominant tree species on the performance of the *** results revealed that semi-natural forests were the most accurately predicted,followed by near-natural and pristine forests,with Matthews correlation coefficient values of 0.32,0.24,and 0.17,*** additional field data did not improve the ***,stratification by species improved the accuracy of predictions for near-natural and semi-natural forests,while reducing accuracy for pristine *** use of horizontal variables did not improve the *** study demonstrates the potential of ALS data in identifying forests with high conservation *** provides a basis for further research on the use of ALS data for the detection and conservation of natural forests,offering valuable insights to guide future forest preservation efforts.

关键词： Natural forest ALS Naturalness Vertical variables Horizontal variables Biodiversity Forest condition Ecosystem services

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：