Environmental data used in the modelling of suitable nesting sites for six forest biodiversity indicator bird species across Finland (part 1)

This repository contains files of spatial environmental data layers which were used as predictors of nesting habitat suitability for six biodiversity indicator bird species in Finland: (i) three hawk species, the European honey buzzard (Pernis apivorus), the northern goshawk (Accipiter gentilis) and the common buzzard (Buteo buteo), and (ii) three woodpecker species, the white-backed woodpecker (Dendrocopos leucotos), the lesser spotted woodpecker (Dryobates minor) and the Eurasian three-toed woodpecker (Picoides tridactylus). These six bird species have been shown to provide useful indicators of different conservation and biodiversity values of boreal forests, such as occurrences of red listed polypores, and indicative of forest characteristics related to old-growth forests such as representative occurrences of dead wood. The modelling spesifically targetted the nest sites of the bird species where the role of critical suitable environmental conditions is elevated. The data of nesting sites of the bird species are not open access data due to its sensitivity, but can be requested for research purposes by sending a query to the head of the Zoology unit at the Finnish Museum of Natural History. However, the Maxent results of the nesting habitat suitability for bird species across the whole of Finland are available in Zenodo (https://doi.org/10.5281/zenodo.4779108). Please also note that the environmental data is split - due to its large size - into two repository locations, this one containing the local site variables and 500 m buffer variables, and the other containing the 1 km buffer variables and the two climate variables. Taken together, 40 different environmental data layers were developed and their information sampled for a 96 x 96 m resolution lattice system covering the whole Finland. These 40 data layers were organised for the modeling into the following groups of predictor variables: (1) Data on forest structure and other forest stand characteristics (96 x 96 m cell) (8 variables), (2) Data on land cover at the forest stand (96 x 96 m cell) (8 variables), (3) Data on forest characteristics in the 500 m landscape buffer area (3 variables), (4) Data on forest characteristics in the 1 km landscape buffer area (3 variables), (5) Data on land cover in the 500 m landscape buffer area, (6) Data on land cover in the 500 m landscape buffer area, and (7) Climate data (2 variables). These data were used to examine what are the key determinants of the nesting site suitability of the six indicator bird species and to developed predictive maps across the whole Finland for the locations of most optimal nesting forest areas. The nesting habitat suitability modelling was done using the MaxEnt model. The forest structure and habitat quality predictor variables were developed based on national forest data gathered from three sources: (i) Finnish Forest Center (FFC), (ii) Metsähallitus Parks & Wildlife (MPW), and (iii) the multi-source national forest inventory carried out by the Natural Resources Institute Finland (LUKE). The land cover variables were measured using the CORINE Land Cover 2018 system, from the database produced, maintained and distributed by SYKE. The two climate variables were initially for the SUMI project by the Finnish Meteorological Institute and further applied in this modelling study. The environmental variables, the six indicator bird species and the processses, steps and choices included in the MaxEnt modelling are described in full detail in the following publication: Virkkala, Raimo, Leikola, Niko, Kujala, Heini, Kivinen, Sonja, Hurskainen, Pekka, Kuusela, Saija, Valkama, Jari and Heikkinen, Risto K.: Developing fine-grained nationwide predictions of valuable forests using biodiversity indicator bird species, Ecological Applications, in press. The details of the environmental data are also described in the read_me.doc file uploaded into this repository.本仓库收录的空间环境数据图层，被用作芬兰6种生物多样性指示鸟类的筑巢栖息地适宜性预测因子。这6种鸟类分别为：(i) 3种鹰类：欧洲蜂鹰（European honey buzzard, Pernis apivorus）、苍鹰（northern goshawk, Accipiter gentilis）与普通鵟（common buzzard, Buteo buteo）；(ii) 3种啄木鸟类：白背啄木鸟（white-backed woodpecker, Dendrocopos leucotos）、小斑啄木鸟（lesser spotted woodpecker, Dryobates minor）以及欧亚三趾啄木鸟（Eurasian three-toed woodpecker, Picoides tridactylus）。 这6种鸟类已被证实可作为寒温带森林不同保护与生物多样性价值的有效指示物种，例如红色名录中多孔菌的出现情况，同时可指示与原始林相关的森林特征，如枯木的典型分布。本建模研究专门针对筑巢位点的关键适宜环境条件作用更为显著的鸟类类群。 由于涉及敏感性信息，该鸟类筑巢位点数据未开放获取，但科研人员可通过向芬兰自然历史博物馆动物学部负责人发送申请邮件，获取相关研究使用权限。不过，芬兰全境鸟类筑巢栖息地适宜性的MaxEnt模型（MaxEnt）结果已上传至Zenodo平台（https://doi.org/10.5281/zenodo.4779108）。 请注意，由于数据体量较大，本环境数据集被拆分至两个仓库存储：本仓库包含局地样地变量与500米缓冲区变量，另一仓库则包含1千米缓冲区变量与2个气候变量。 综上，本研究共构建40种不同的环境数据图层，并以覆盖芬兰全境的96×96米分辨率格网系统采集其信息。这40个数据图层被划分为以下7组预测变量： 1. 林分结构与其他林分特征数据（96×96米栅格单元）：共8个变量； 2. 林分尺度土地覆被数据（96×96米栅格单元）：共8个变量； 3. 500米景观缓冲区内的森林特征数据：共3个变量； 4. 1千米景观缓冲区内的森林特征数据：共3个变量； 5. 500米景观缓冲区内的土地覆被数据； 6. 500米景观缓冲区内的土地覆被数据； 7. 气候数据：共2个变量。 上述数据被用于探究这6种指示鸟类筑巢位点适宜性的关键决定因子，并绘制芬兰全境最优筑巢森林区域的预测分布图。本研究采用MaxEnt模型开展筑巢栖息地适宜性建模。 林分结构与栖息地质量预测变量基于三类数据源的国家森林调查数据构建：(i) 芬兰森林中心（Finnish Forest Center, FFC）；(ii) 芬兰国家公园与野生动物管理局（Metsähallitus Parks & Wildlife, MPW）；(iii) 芬兰自然资源研究所（Natural Resources Institute Finland, LUKE）开展的多源国家森林清查数据。土地覆被变量基于SYKE维护、发布的CORINE Land Cover 2018数据库进行测算。2个气候变量最初为芬兰气象研究所的SUMI项目数据集，并在本建模研究中进一步应用。 本研究的环境变量、6种指示鸟类以及MaxEnt建模所涉及的流程、步骤与选择，均在以下发表论文中进行了详细阐述：Virkkala, Raimo, Leikola, Niko, Kujala, Heini, Kivinen, Sonja, Hurskainen, Pekka, Kuusela, Saija, Valkama, Jari and Heikkinen, Risto K.: Developing fine-grained nationwide predictions of valuable forests using biodiversity indicator bird species, Ecological Applications, in press. 环境数据的详细说明也可参见本仓库上传的read_me.doc文件。