Fauna Corridors for North East NSW

## **Abstract** \n\nThis dataset and its metadata statement were supplied to the Bioregional Assessment Programme by a third party and are presented here as originally supplied:\n\n\n\nLayer of regional and subregional linking corridors for fauna of the Upper North East (UNE) and Lower North East (LNE) NSW RFA regions. A new GIS program, NPWS CORRIDORS, was used to derive potential landscape linkages (habitat corridors) based on the predicted distributions of priority fauna species assemblages (see metadata for fauna key habitats). These ESRI grid outputs were refined, under a series of decision rules, to derive final corridor ESRI shapefile polygons. The final corridors map layer is a regional representation displaying the most likely occurrence of linking corridors for fauna consolidated at the regional scale. The mapping and derivation has been based on state-of-the-art data and GIS tools combined with qualitative interpretation based on ecological principles and expertise. As of April 2001, the mapping has not been formally field tested and the methods have not been peer-reviewed outside several conference and workshop presentations, all well received. A journal paper and project report are in preparation.\n\n\n\nAdditional metadata \n\nGilmore, A. M. and Parnaby, H. E., 1994. Vertebrate Fauna of Conservation Concern in North-East NSW Forests. North East Forests Biodiversity Study, Report No. 3e, unpublished report, NSW National Parks and Wildlife Service. Metadata statement for UNE/LNE Key Habitats. Metadata statement for UNE/LNE RFA Centres of Endemism. NPWS, 1994a. Environmental GIS database for north-east NSW. North East Forests Biodiversity Study, Report No. 2, unpublished report, NSW National Parks and Wildlife Service. NPWS, 1994b. Fauna of North-East NSW Forests. North East Forests Biodiversity Study, Report No. 3, unpublished report, NSW National Parks and Wildlife Service. NPWS 1999. Modelling areas of habitat significance for vertebrate fauna and vascular flora in north east NSW. A project undertaken for the Joint Commonwealth NSW Regional Forest Agreement Steering Committee as part of the NSW Comprehensive Regional Assessments. Scotts, D., Drielsma, M, Whish, G. and Kingma, L. in prep. Regional key habitats and corridors for forest fauna of north-east New South Wales; a framework to focus conservation planning, assessment and management.\n\n## **Dataset History** \n\nLineage: Lineage The process employed in deriving fauna corridors is explicit and repeatable in as much as: \\* The fauna species models, which are the basic biodiversity entities that the project seeks to summarise and integrate are stored and held by NPWS; \\* All relevant data layers, developed at each stage of the project, are stored and held by NPWS; \\* The Geographic Information System (GIS) tools developed for the analyses are available as extensions to the ARCVIEW GIS. At numerous stages of the analyses, informed interpretation of outputs and assignment of thresholds has been required to move the process along or to finalise an output. Any qualitative decisions taken have been based on the project manager's ecological expertise and knowledge of the data sets being considered. Habitat corridors have been mapped across public and private lands. The process of deriving and mapping regional corridors for fauna has involved the use of fauna assemblage distributions and fauna key habitats (see additional metadata referenced below), as surrogates for areas of high fauna conservation, and as the actual habitats to be linked. This involved a 4 step process which is detailed below: STEP 1. UNDERTAKE LEAST COST PATHWAYS ANALYSES TO DERIVE POTENTIAL REGIONAL AND SUB-REGIONAL CORRIDORS A technique has been developed and refined by the Research and Development Unit of the NPWS GIS Division to aid with the delineation of habitat corridors; NPWS CORRIDORS is used as an extension to the ARCVIEW GIS program. CORRIDORS is used to identify the pathways that most efficiently link identified significant landscape elements or habitats. The program operates under the principle that species, and their constituent genes, are most likely to move (while foraging, dispersing, breeding, migrating) along gradients of preferred habitat; non-preferred habitats representing varying levels of impedance or even barriers. For any particular biodiversity entity, in this case species assemblages, the most efficient landscape links are those that exact the "least cost", in terms of energy expenditure, for their use. More favourable habitats, be it for foraging, roosting, nesting or as transitory movements, are assumed to exact less cost for their use than less favourable marginal or non-habitats. Non-habitats may include areas of native vegetation that are simply not suitable for use by the species assemblage concerned. They also include areas that have been cleared of native vegetation and developed for human uses such as agriculture and urban expansion. The basic requirement of the CORRIDORS program is a "cost grid". This is a continuous probability surface covering the entire study area and describing the relative costs, to a particular biodiversity entity (e.g. a species or species assemblage), of utilizing each grid cell within the area as habitat, or as a potential linking pathway. Cost grids were derived for the KHC Project through a combination of the assemblage habitat map layer and existing maps of extant vegetation and land tenure. The derived cost grids reflect levels of habitat suitability and tenure class for every grid cell available as a potential linking pathway. Predicted habitats for the assemblage are deemed the least costly pathways, the best predicted habitat class (class 3) carrying the least cost. Extant vegetation that is not predicted habitat represents a less costly path than cleared land. Within each habitat suitability class, tenure is weighted to place greater cost on private lands as opposed to public lands and, within public lands, a greater cost on state forests as opposed to NPWS estate and Crown Reserves managed by NPWS. The effect of tenure weightings is to favour reserved lands over state forests over private lands as corridor links, all else being equal. Additional costs were applied to mapped estuaries making it more "costly", but not impossible, for the program to link across these features, relative to alternative links, all else being equal. The CORRIDORS program utilizes paired reference points, assigned in an iterative manner and apportioned within focal habitat types (e.g. assemblage habitats and key habitats), which it works to via the most efficient pathways available according to the cost grid. The reference points are directed into identified strategic areas, making them focal areas for landscape links. For the purposes of the KHC Project analyses 10,000 reference points were used and assigned to the predicted assemblage habitats with a minimum proportion directed into fauna core habitats. In seeking to establish the most ecologically valid corridor network for the KHC Project study areas the LCP analyses were undertaken at two levels: Level 1: a CORRIDORS analysis for each of the each identified fauna assemblage independently (7 for UNC, 7 for LNC, 6 for TAB and 5 for SYD); Level 2: a CORRIDORS analysis for the combined assemblages within each study area. These two levels were selected in order to pursue the goal of enhancing overall landscape connectivity. The first level will establish potential corridor links for species within each assemblage, a clear goal of landscape ecology. The second level will consolidate the landscape approach, whereby the mosaics of habitats and species assemblages across a landscape are treated as one functional system, another ecological requirement enhancing overall landscape connectivity. These between assemblage corridors are also intended to provide for larger scale dispersal and movement (e.g. migration) between predicted assemblage habitats. The CORRIDORS outputs are continuous probability surface models (map layers) depicting the pathways of least cost linking habitats, and particularly core habitats, of each fauna assemblage individually, plus a combined assemblages run for each KHC study area. These map layers can be used as planning entities in their own right or, as in this project, can be combined and weighted to derive regional and sub-regional corridors. STEP 2. DERIVING REGIONAL AND SUB-REGIONAL CORRIDOR GRIDS FROM "CORRIDORS" PROGRAM OUTPUTS The CORRIDORS outputs represent potential corridors; assessing them and moving them from potential corridors to Regional and Sub-regional corridors followed another set process for each KHC study area: A. Reclassify the continuous probability surface layers depicting the potential corridors for each assemblage to five classes; 0,1,2,3,4, based on perceived thresholds of significance, with class 4 being those potential corridors at the highest probability end of the scale, and of the highest priority for that assemblage; B. Do the same for the between assemblage potential corridors for each KHC study area; C. For each KHC study area, combine the classified assemblage, and between assemblage corridor grids and sum the combined classes; D. Apply thresholds to delineate Regional and Sub-regional corridors; E. For interim display purposes (prior to final conversion of the grid map layers to polygon map layers) use existing vegetation mapping to intersect the derived corridors map layers and display vegetated and non-vegetated portions of the regional and sub-regional corridors. Regional and sub-regional corridors extend across all tenures with certain private lands being crucial links in the network. In many instances, the least costly pathway to link some assemblage habitats crossed cleared lands. The potential regional and sub-regional corridor grid map layers depicting potential corridors linking predicted fauna assemblage habitats are available for each KHC study area and as a combined potential corridors map layer for the entire KHC area. These map layers can be used as planning entities in their own right but the final stage of the KHC Project (mapping phase) was to undertake final assessment and refinement of the potential regional and sub-regional corridors and to convert them to final polygon layers for implementation on planning and management programs. STEP 3. REFINING THE POTENTIAL CORRIDOR GRID MAP LAYERS TO FINAL CORRIDOR POLYGON LAYERS The potential corridor map layers are useful as planning entities in their own right, providing an index of the importance of the respective corridors identified within the parameters of the analytical programs employed. However, not all of the potential corridors identified by the CORRIDORS process are sensible, from either ecological or practical planning perspectives. Second, the potential corridor grid layers are not easily adaptable to direct field implementation seeking to place the corridors on the ground and determine boundaries. Third, further interpretation is required to tailor the corridors to the fauna assemblages for which they have been derived (Bennett 1999). A process of assessment and refinement of the potential corridors is the final stage of the KHC Project (mapping phase) whereby the potential corridor grid map layers are converted to final polygons with defined boundaries. In this process certain potential corridors are accentuated and extraneous potential corridors are ignored. An approach incorporating "focal species" (after Lambeck 1997) was used to tailor the final dimensions of corridors. It is anticipated that this polygon output will be the most appropriate for provision to planners, managers and community groups. A technique has been developed and refined by the Research and Development Unit of the NPWS GIS Division as a means of refining grid data layers, such as the potential corridors data, to clearer polygon planning units; POLYEDIT is used as an extension to the ARCVIEW GIS program. POLYEDIT POLYEDIT allows the user to select portions of continuous or classified grid map layers for refinement and categorisation. For example, a portion of the potential corridor grid layer can be selected which corresponds to a particular, locally identifiable, part of the landscape. By refining and naming the selected corridor portion the refined corridor can take on a "life of its own" and be recognisable by local planners, managers and community groups. The program allows the progressive and cumulative refinement of the entire grid layer in this manner. After selecting the portion of the grid layer to be refined POLYEDIT requires the user to apply a threshold to the grid, parts of the grid below the threshold will be retained within the derived polygon, the excess will be ignored. The polygon can then be edited to reflect aspects such as pre-determined corridor widths, tenure boundaries and local topography, as indicated by 1:25,000 topographic map layers. By combining the functions provided in the POLYEDIT program, coupled with the shape editing capabilities of ARCVIEW, virtually any configuration of shapes can be readily derived to refine the polygon outputs in line with the mapped features available to the user. An additional feature of the POLYEDIT program allows the user to identify known corridors that the CORRIDORS analyses have not delineated (non-LCP corridors). This POLYEDIT feature requires the user to outline the non-system corridor, by on-screen digitising. For the KHC Project, POLYEDIT was incorporated into the process of assessment and refinement of potential corridors in the following manner: A. Visual assessment of the potential corridor layers, within Arcview, against available vegetation mapping, LANDSAT imagery, 1:25,000 topographic maps and tenure maps; B. Acceptance or rejection of the potential corridors, and identification of any non-system corridors based on decision rules; C. Refinement of accepted corridor boundaries, utilising POLYEDIT in combination with vegetation mapping, LANDSAT imagery and topographic maps; D. Delineation of public land and private land corridors separately; E. Implementation of available information on focal species' home ranges, movement and dispersal abilities in modifying and finalising final corridor widths; F. Editing of the polygon attributes table, within ARCVIEW, to summarise decisions made in the refinement process; this included a scoring procedure to assess the overall status of each corridor according to six criteria; G. Final designation of corridors to the categories, Regional or Sub-regional according to the overall score thresholds. STEP 4. CONSOLIDATE THE FINAL CORRIDORS MAP LAYER The final corridors shapefile includes an attributes table that includes the following fields: Name- each individual corridor polygon has been derived independently. Those within NPWS or NSW SF estate are designated the name of the reserve or state forest within which they have been mapped. Those on private lands and crown lands other than NPWS, SF are designated a name indicative of the geographic location in which they occur. Class- the default display field- Regional Corridors are deemed the most important links, typically linking reserves to other reserves, public lands or significant key habitat patches; they often follow natural gradients. Subregional Corridors are also important links but may be alternative or secondary links, more fragmented links, may link regional corridors to other corridors or public lands; they often cross natural gradients. Origin- 1.- Corridors mapped directly from CORRIDORS system analysis; 2. Corridors based on CORRIDORS system analysis but boundaries or pathway modified in accordance with refinement mapping; 3.- Corridors mapped from other sources (eg. Coastal Corridor, mapped Koala Plan corridors; Roads and Traffic Authority Pacific Highway underpass corridors. Notes- For private lands-based corridors only. This field highlights the fauna assemblage(s) for which the corridor has been mapped. A between assemblages note indicates that the corridor was identified and mapped from the "between assemblages" CORRIDORS analysis. Focal Species- For private lands-based corridors only. A broad indication of the focal species for which the overall corridor dimensions were designed- a reflection of the focal species' potential spatial requirements. The focal species reflect the assemblage for which the corridor was mapped. Corridor Score- For private lands-based corridors only. Potential corridors were scored for their conservation value and class designation. The higher the score the higher the perceived corridor conservation value. Corridor scores from 7-10 yielded a "Sub-regional" class rank; scores of 11-18 yielded a "regional" class rank. RTA-Koala- "RTA underpass corridors" coincide with ameliorative fauna underpasses or culverts installed during upgrading works for the Pacific Highway (up until the March 2001). "Koala Corridors" were mapped for Koala Management Plans and included as part of the regional network; as of March 2001 only Coffs Harbour Koala corridors were available for inclusion. Positional Accuracy Species assemblage distributions, key habitats and corridors have been derived from interpolated species distributions generated by modelling point locality species records (with a spatial accuracy of approximately 100m) in relation to mapped environmental layers (with a map scale of 1:100 000 to 1:250 000) (see additional metadata). The CORRIDORS analysis was undertaken at the 500m grid cell size in order to reduce computational burden. The outputs were re-sampled to 100m grid cell for display and storage. In applying and interpreting the key habitats map layer it should always be remembered that they are based on modelled data and have been developed at the regional scale, to inform regional land, water and vegetation reform programs. The mapped products represent a state-of-the-art consolidation of fauna information for UNE and LNE areas but should be interpreted in terms of a likelihood of occurrence of fauna key habitats; they are indicative representations (see mapping caveat). It should also be noted that the process of development of the key habitats layer has necessarily included qualitative judgements relating to interpretations and setting of thresholds; these have been made based on ecological expertise and explicit decision rules. Attribute Accuracy The species assemblage distributions, derived key habitats, and ultimately the corridors layer are a direct reflection of the species distributional models from which they are developed (see Additional Metadata). The extent to which the predicted corridors in fact support the assemblages or priority species for which they have been delineated will vary between species, assemblages and areas. Field evaluation surveys are required to further assess the attribute accuracy. The form of the assemblage distributions lend themselves ideally to field-based evaluation and monitoring; the occurrence of relative proportions of the species comprising relevant assemblages can be used to assess the predictions. Logical Consistency The Corridors shapefile comprises many individual corridor polygons, each mutually exclusive. Completeness The derived fauna key habitat grid is restricted to the extent of native forest defined by the Forest Ecosystems map layer derived for UNE and LNE RFA studies. For the purposes of this project these layers have been further restricted to delete areas mapped as forestry plantation, agricultural plantation, pasture and cropland, introduced scrub, cleared / partially cleared, camphor laurel. These were mapped categories that were not assigned a conservation target in the RFA process. Lineage The process employed in deriving fauna corrodrs is explicit and repeatable in as much as: \\* The fauna species models, which are the basic biodiversity entities that the project seeks to summarise and integrate are stored and held by NPWS; \\* All relevant data layers, developed at each stage of the project, are stored and held by NPWS; \\* The Geographic Information System (GIS) tools developed for the analyses are available as extensions to the ARCVIEW GIS. At numerous stages of the analyses, informed interpretation of outputs and assignment of thresholds has been required to move the process along or to finalise an output. Any qualitative decisions taken have been based on the project manager's ecological expertise and knowledge of the data sets being considered. Habitat corridors have been mapped across public and private lands. The process of deriving and mapping regional corridors for fauna has involved the use of fauna assemblage distributions and fauna key habitats (see additional metadata referenced below), as surrogates for areas of high fauna conservation, and as the actual habitats to be linked. This involved a 4 step process which is detailed below: STEP 1. UNDERTAKE LEAST COST PATHWAYS ANALYSES TO DERIVE POTENTIAL REGIONAL AND SUB-REGIONAL CORRIDORS A technique has been developed and refined by the Research and Development Unit of the NPWS GIS Division to aid with the delineation of habitat corridors; NPWS CORRIDORS is used as an extension to the ARCVIEW GIS program. CORRIDORS is used to identify the pathways that most efficiently link identified significant landscape elements or habitats. The program operates under the principle that species, and their constituent genes, are most likely to move (while foraging, dispersing, breeding, migrating) along gradients of preferred habitat; non-preferred habitats representing varying levels of impedance or even barriers. For any particular biodiversity entity, in this case species assemblages, the most efficient landscape links are those that exact the "least cost", in terms of energy expenditure, for their use. More favourable habitats, be it for foraging, roosting, nesting or as transitory movements, are assumed to exact less cost for their use than less favourable marginal or non-habitats. Non-habitats may include areas of native vegetation that are simply not suitable for use by the species assemblage concerned. They also include areas that have been cleared of native vegetation and developed for human uses such as agriculture and urban expansion. The basic requirement of the CORRIDORS program is a "cost grid". This is a continuous probability surface covering the entire study area and describing the relative costs, to a particular biodiversity entity (e.g. a species or species assemblage), of utilizing each grid cell within the area as habitat, or as a potential linking pathway. Cost grids were derived for the KHC Project through a combination of the assemblage habitat map layer and existing maps of extant vegetation and land tenure. The derived cost grids reflect levels of habitat suitability and tenure class for every grid cell available as a potential linking pathway. Predicted habitats for the assemblage are deemed the least costly pathways, the best predicted habitat class (class 3) carrying the least cost. Extant vegetation that is not predicted habitat represents a less costly path than cleared land. Within each habitat suitability class, tenure is weighted to place greater cost on private lands as opposed to public lands and, within public lands, a greater cost on state forests as opposed to NPWS estate and Crown Reserves managed by NPWS. The effect of tenure weightings is to favour reserved lands over state forests over private lands as corridor links, all else being equal. Additional costs were applied to mapped estuaries making it more "costly", but not impossible, for the program to link across these features, relative to alternative links, all else being equal. The CORRIDORS program utilizes paired reference points, assigned in an iterative manner and apportioned within focal habitat types (e.g. assemblage habitats and key habitats), which it works to via the most efficient pathways available according to the cost grid. The reference points are directed into identified strategic areas, making them focal areas for landscape links. For the purposes of the KHC Project analyses 10,000 reference points were used and assigned to the predicted assemblage habitats with a minimum proportion directed into fauna core habitats. In seeking to establish the most ecologically valid corridor network for the KHC Project study areas the LCP analyses were undertaken at two levels: Level 1: a CORRIDORS analysis for each of the each identified fauna assemblage independently (7 for UNC, 7 for LNC, 6 for TAB and 5 for SYD); Level 2: a CORRIDORS analysis for the combined assemblages within each study area. These two levels were selected in order to pursue the goal of enhancing overall landscape connectivity. The first level will establish potential corridor links for species within each assemblage, a clear goal of landscape ecology. The second level will consolidate the landscape approach, whereby the mosaics of habitats and species assemblages across a landscape are treated as one functional system, another ecological requirement enhancing overall landscape connectivity. These between assemblage corridors are also intended to provide for larger scale dispersal and movement (e.g. migration) between predicted assemblage habitats. The CORRIDORS outputs are continuous probability surface models (map layers) depicting the pathways of least cost linking habitats, and particularly core habitats, of each fauna assemblage individually, plus a combined assemblages run for each KHC study area. These map layers can be used as planning entities in their own right or, as in this project, can be combined and weighted to derive regional and sub-regional corridors. STEP 2. DERIVING REGIONAL AND SUB-REGIONAL CORRIDOR GRIDS FROM "CORRIDORS" PROGRAM OUTPUTS The CORRIDORS outputs represent potential corridors; assessing them and moving them from potential corridors to Regional and Sub-regional corridors followed another set process for each KHC study area: A. Reclassify the continuous probability surface layers depicting the potential corridors for each assemblage to five classes; 0,1,2,3,4, based on perceived thresholds of significance, with class 4 being those potential corridors at the highest probability end of the scale, and of the highest priority for that assemblage; B. Do the same for the between assemblage potential corridors for each KHC study area; C. For each KHC study area, combine the classified assemblage, and between assemblage corridor grids and sum the combined classes; D. Apply thresholds to delineate Regional and Sub-regional corridors; E. For interim display purposes (prior to final conversion of the grid map layers to polygon map layers) use existing vegetation mapping to intersect the derived corridors map layers and display vegetated and non-vegetated portions of the regional and sub-regional corridors. Regional and sub-regional corridors extend across all tenures with certain private lands being crucial links in the network. In many instances, the least costly pathway to link some assemblage habitats crossed cleared lands. The potential regional and sub-regional corridor grid map layers depicting potential corridors linking predicted fauna assemblage habitats are available for each KHC study area and as a combined potential corridors map layer for the entire KHC area. These map layers can be used as planning entities in their own right but the final stage of the KHC Project (mapping phase) was to undertake final assessment and refinement of the potential regional and sub-regional corridors and to convert them to final polygon layers for implementation on planning and management programs. STEP 3. REFINING THE POTENTIAL CORRIDOR GRID MAP LAYERS TO FINAL CORRIDOR POLYGON LAYERS The potential corridor map layers are useful as planning entities in their own right, providing an index of the importance of the respective corridors identified within the parameters of the analytical programs employed. However, not all of the potential corridors identified by the CORRIDORS process are sensible, from either ecological or practical planning perspectives. Second, the potential corridor grid layers are not easily adaptable to direct field implementation seeking to place the corridors on the ground and determine boundaries. Third, further interpretation is required to tailor the corridors to the fauna assemblages for which they have been derived (Bennett 1999). A process of assessment and refinement of the potential corridors is the final stage of the KHC Project (mapping phase) whereby the potential corridor grid map layers are converted to final polygons with defined boundaries. In this process certain potential corridors are accentuated and extraneous potential corridors are ignored. An approach incorporating "focal species" (after Lambeck 1997) was used to tailor the final dimensions of corridors. It is anticipated that this polygon output will be the most appropriate for provision to planners, managers and community groups. A technique has been developed and refined by the Research and Development Unit of the NPWS GIS Division as a means of refining grid data layers, such as the potential corridors data, to clearer polygon planning units; POLYEDIT is used as an extension to the ARCVIEW GIS program. POLYEDIT POLYEDIT allows the user to select portions of continuous or classified grid map layers for refinement and categorisation. For example, a portion of the potential corridor grid layer can be selected which corresponds to a particular, locally identifiable, part of the landscape. By refining and naming the selected corridor portion the refined corridor can take on a "life of its own" and be recognisable by local planners, managers and community groups. The program allows the progressive and cumulative refinement of the entire grid layer in this manner. After selecting the portion of the grid layer to be refined POLYEDIT requires the user to apply a threshold to the grid, parts of the grid below the threshold will be retained within the derived polygon, the excess will be ignored. The polygon can then be edited to reflect aspects such as pre-determined corridor widths, tenure boundaries and local topography, as indicated by 1:25,000 topographic map layers. By combining the functions provided in the POLYEDIT program, coupled with the shape editing capabilities of ARCVIEW, virtually any configuration of shapes can be readily derived to refine the polygon outputs in line with the mapped features available to the user. An additional feature of the POLYEDIT program allows the user to identify known corridors that the CORRIDORS analyses have not delineated (non-LCP corridors). This POLYEDIT feature requires the user to outline the non-system corridor, by on-screen digitising. For the KHC Project, POLYEDIT was incorporated into the process of assessment and refinement of potential corridors in the following manner: A. Visual assessment of the potential corridor layers, within Arcview, against available vegetation mapping, LANDSAT imagery, 1:25,000 topographic maps and tenure maps; B. Acceptance or rejection of the potential corridors, and identification of any non-system corridors based on decision rules; C. Refinement of accepted corridor boundaries, utilising POLYEDIT in combination with vegetation mapping, LANDSAT imagery and topographic maps; D. Delineation of public land and private land corridors separately; E. Implementation of available information on focal species' home ranges, movement and dispersal abilities in modifying and finalising final corridor widths; F. Editing of the polygon attributes table, within ARCVIEW, to summarise decisions made in the refinement process; this included a scoring procedure to assess the overall status of each corridor according to six criteria; G. Final designation of corridors to the categories, Regional or Sub-regional according to the overall score thresholds. STEP 4. CONSOLIDATE THE FINAL CORRIDORS MAP LAYER The final corridors shapefile includes an attributes table that includes the following fields: " Name- each individual corridor polygon has been derived independently. Those within NPWS or NSW SF estate are designated the name of the reserve or state forest within which they have been mapped. Those on private lands and crown lands other than NPWS, SF are designated a name indicative of the geographic location in which they occur. " Class- the default display field- Regional Corridors are deemed the most important links, typically linking reserves to other res

**摘要**

本数据集及其元数据声明由第三方提交至生物区域评估计划，现按原始提交版本在此呈现：

该图层为新南威尔士州东北部上区（UNE）和东北部下区（LNE）区域森林协议（RFA）区域的野生动物区域及次区域连接廊道。研究依托一款全新的地理信息系统（GIS）工具NPWS CORRIDORS，基于优先野生动物类群的预测分布（详见野生动物关键栖息地元数据）推导潜在景观连接廊道（生境廊道）。经一系列决策规则对这些ESRI网格输出结果进行优化，最终得到廊道ESRI形状文件多边形。最终的廊道地图图层以区域尺度呈现，展示了野生动物连接廊道最可能的分布区域，实现了区域尺度的整合。本制图与推导流程结合了前沿数据与GIS工具，并辅以基于生态学原理与专业知识的定性解读。截至2001年4月，本制图尚未经过正式的野外验证，相关方法仅在数次会议与研讨会报告中进行过同行评议且反响良好，目前暂无正式期刊论文与项目报告发表，相关成果正在筹备中。

附加元数据

Gilmore, A. M. 与 Parnaby, H. E., 1994. 《新南威尔士州东北部森林中受保护关注的脊椎动物群》。东北森林生物多样性研究，报告第3e号，未出版报告，新南威尔士国家公园与野生动物服务局（NPWS）。UNE/LNE关键栖息地元数据声明。UNE/LNE RFA特有性中心元数据声明。NPWS, 1994a. 《新南威尔士州东北部环境GIS数据库》。东北森林生物多样性研究，报告第2号，未出版报告，NPWS。NPWS, 1994b. 《新南威尔士州东北部森林野生动物群》。东北森林生物多样性研究，报告第3号，未出版报告，NPWS。NPWS 1999. 《新南威尔士州东北部脊椎动物与维管植物重要生境建模》。为英联邦-新南威尔士州联合区域森林协议指导委员会开展的项目，作为新南威尔士州综合区域评估的一部分。Scotts, D., Drielsma, M, Whish, G. 与 Kingma, L. 待出版。《新南威尔士州东北部森林野生动物的区域关键生境与廊道：聚焦保护规划、评估与管理的框架》。

## **数据集历史**

溯源： 野生动物廊道的推导流程清晰明确且可复现，具体如下： * 作为项目核心生物多样性单元的野生动物物种模型，由NPWS存储与管理； * 所有相关数据图层，在项目各阶段开发完成后均由NPWS存储与管理； * 本分析所用的地理信息系统（GIS）工具可作为ARCview GIS的扩展工具获取。
在分析的多个阶段，需对输出结果进行专业解读并设定阈值，以推进流程或完成最终输出。任何定性决策均基于项目负责人的生态学专业知识与对所用数据集的了解。本研究已在公共与私有土地上完成生境廊道制图。

野生动物区域廊道的推导与制图流程，以野生动物类群分布与野生动物关键栖息地（详见下文引用的附加元数据）作为高野生动物保护价值区域的替代指标，并作为待连接的实际生境。该流程包含以下四个步骤，详述如下：

STEP 1. 开展最小成本路径分析以推导潜在区域与次区域廊道
NPWS GIS部门研发部开发并优化了一项用于生境廊道划定的技术，将NPWS CORRIDORS作为ARCview GIS的扩展工具使用。CORRIDORS工具可识别出能够最高效连接已识别重要景观要素或生境的路径。该程序遵循以下原理：物种及其携带的基因在觅食、扩散、繁殖、迁徙过程中，更倾向于沿偏好生境的梯度移动；非偏好生境则会构成不同程度的阻碍甚至屏障。对于特定生物多样性单元（本研究中为野生动物类群），最高效的景观连接路径即消耗能量最少的“最小成本”路径。相较于较差的边缘生境或非生境，更适宜的生境（无论用于觅食、栖息、筑巢还是临时移动）所需的能量成本更低。非生境包括完全不适用于目标野生动物类群的原生植被区域，以及已被清理并用于农业、城市扩张等人类活动的区域。

CORRIDORS程序的基本需求为“成本网格”，即覆盖整个研究区域的连续概率表面，用于描述特定生物多样性单元（如物种或类群）利用区域内每个网格细胞作为生境或潜在连接路径的相对成本。KHC项目的成本网格由类群生境图层、现有现存植被地图与土地权属地图结合推导得出。推导得到的成本网格反映了每个可用作潜在连接路径的网格细胞的生境适宜性等级与土地权属类别。类群的预测生境被视为成本最低的路径，其中最佳预测生境等级（等级3）的成本最低。非预测生境的现存植被的通行成本高于预测生境，但低于已清理土地。在每个生境适宜性等级内，土地权属被赋予不同权重：私有土地的权重高于公共土地；在公共土地中，州立森林的权重高于NPWS管理的不动产与 Crown 保留地。在其他条件相同的情况下，权属权重的设置会优先选择保留地，其次是州立森林，最后是私有土地作为廊道连接。此外，研究还为已测绘的河口增设了额外成本，使得程序跨越这些区域的成本高于其他替代路径，但并非完全无法通行。

CORRIDORS程序采用成对参考点，以迭代方式分配至焦点生境类型（如类群生境与关键栖息地），程序会根据成本网格选择最高效的路径连接这些参考点。参考点被定向至已识别的战略区域，成为景观连接的焦点区域。在KHC项目的分析中，共设置10000个参考点，分配至预测的类群生境中，其中至少有一部分被分配至野生动物核心栖息地。

为在KHC项目研究区域内构建最符合生态学逻辑的廊道网络，最小成本路径（LCP）分析分为两个层级开展：
Level 1: 针对每个已识别的野生动物类群独立开展CORRIDORS分析（UNC区域7个、LNC区域7个、TAB区域6个、SYD区域5个）；
Level 2: 针对每个研究区域内的合并类群开展CORRIDORS分析。
设置这两个层级的目的是提升整体景观连通性。第一层级将为每个类群内的物种建立潜在廊道连接，这是景观生态学的明确目标。第二层级则整合了景观方法，将景观中的生境与物种类群镶嵌体视为一个功能整体，这是提升整体景观连通性的另一项生态学要求。这些跨类群廊道还可支持预测生境之间的大规模扩散与移动（如迁徙）。

CORRIDORS的输出结果为连续概率表面模型（地图图层），展示了每个单独野生动物类群的最小成本连接路径（尤其是核心栖息地），以及每个KHC研究区域的合并类群运行结果。这些地图图层可直接作为规划单元使用，或如本项目一般，通过组合与加权得到区域与次区域廊道。

STEP 2. 从“CORRIDORS”程序输出中推导区域与次区域廊道网格
CORRIDORS的输出结果为潜在廊道；将其从潜在廊道优化为区域与次区域廊道，需针对每个KHC研究区域遵循以下流程：
A. 将每个类群的潜在廊道连续概率表面图层，根据感知到的重要性阈值重新分类为5个等级：0,1,2,3,4，其中等级4代表概率最高、对该类群优先级最高的潜在廊道；
B. 对每个KHC研究区域的跨类群潜在廊道执行相同的重新分类操作；
C. 针对每个KHC研究区域，将已分类的类群廊道网格与跨类群廊道网格合并，并对合并后的等级求和；
D. 应用阈值划定区域与次区域廊道；
E. 为临时展示目的（在将网格地图图层最终转换为多边形地图图层之前），使用现有植被地图与推导得到的廊道地图图层相交，以展示区域与次区域廊道的植被覆盖与非植被覆盖部分。

区域与次区域廊道覆盖所有土地权属类型，其中部分私有土地是网络中的关键连接节点。在许多情况下，连接部分类群生境的最小成本路径会穿过已清理土地。每个KHC研究区域均有潜在区域与次区域廊道网格图层，用于展示连接预测野生动物类群生境的潜在廊道，同时也有覆盖整个KHC区域的合并潜在廊道地图图层。这些图层可直接作为规划单元使用，但KHC项目的最终阶段（制图阶段）需对潜在区域与次区域廊道开展最终评估与优化，并将其转换为最终多边形图层，以应用于规划与管理程序。

STEP 3. 将潜在廊道网格地图图层优化为最终廊道多边形图层
潜在廊道地图图层本身可作为规划单元，为所识别廊道在所用分析程序参数下的重要性提供索引。然而，从生态学或实际规划角度来看，CORRIDORS流程识别出的部分潜在廊道并不合理。其次，潜在廊道网格图层难以直接应用于野外实施，无法直接将廊道落地并确定边界。第三，需进一步解读以将廊道适配至其推导所用的野生动物类群（Bennett 1999）。

对潜在廊道的评估与优化是KHC项目制图阶段的最终步骤，即将潜在廊道网格地图图层转换为具有明确边界的最终多边形。在此过程中，部分潜在廊道会被强化，无关的潜在廊道则会被剔除。研究采用了结合“关键物种（focal species）”（参考Lambeck 1997）的方法来确定廊道的最终尺寸。预计该多边形输出结果将是提供给规划者、管理者与社区团体的最适宜形式。

NPWS GIS部门研发部开发并优化了一项技术，用于将潜在廊道这类网格数据图层优化为更清晰的多边形规划单元，将POLYEDIT作为ARCview GIS的扩展工具使用。POLYEDIT工具允许用户选择连续或已分类的网格地图图层的部分区域进行优化与分类。例如，可选择潜在廊道网格图层中对应某一特定、可本地识别的景观部分的区域。通过优化并命名所选廊道区域，优化后的廊道可拥有独立的标识，便于本地规划者、管理者与社区团体识别。该程序允许以这种方式对整个网格图层进行逐步累积式优化。

在选择需优化的网格图层部分后，POLYEDIT要求用户为网格设定阈值，低于阈值的网格部分将保留在推导得到的多边形中，超出部分将被剔除。随后可编辑多边形以反映预设廊道宽度、土地权属边界与局部地形等信息，这些信息可从1:25,000比例尺的地形地图图层获取。结合POLYEDIT的功能与ARCview的形状编辑能力，几乎可根据用户可用的测绘特征推导出任意形状的配置，以优化多边形输出结果。POLYEDIT工具的另一项功能允许用户识别CORRIDORS分析未划定的已知廊道（非LCP廊道），用户需通过屏幕数字化勾勒出非系统廊道。

针对KHC项目，POLYEDIT以下列方式被纳入潜在廊道的评估与优化流程：
A. 在Arcview中对照现有植被地图、陆地卫星（LANDSAT）影像、1:25,000比例尺地形地图与土地权属地图，对潜在廊道图层开展目视评估；
B. 根据决策规则决定保留或剔除潜在廊道，并识别任何非系统廊道；
C. 结合植被地图、LANDSAT影像与地形地图，利用POLYEDIT优化已接受廊道的边界；
D. 分别划定公共土地与私有土地廊道；
E. 利用现有关键物种家域、移动与扩散能力的信息，调整并确定最终廊道宽度；
F. 在ARCview中编辑多边形属性表，以总结优化过程中做出的决策，其中包含一项评分程序，用于根据六项标准评估每个廊道的整体状态；
G. 根据整体评分阈值，最终将廊道划定为区域廊道或次区域廊道类别。

STEP 4. 整合最终廊道地图图层
最终的廊道形状文件包含一个属性表，其中包含以下字段：
Name- 每个单独的廊道多边形均独立推导得到。位于NPWS或新南威尔士州立森林（NSW SF）不动产内的廊道，以其所在保护区或州立森林的名称命名。位于私有土地与除NPWS、州立森林以外的 crown 土地上的廊道，以其所在地理位置命名。
Class- 默认显示字段。区域廊道被视为最重要的连接节点，通常连接保护区与其他res