Alpine Redspot Dragonfly Indicative Distribution in NSW

The Alpine Redspot Dragonfly (Austropetalia tonyana) is a\r\nmoderate-sized dragonfly. The larvae grow to 32-35mm long and\r\nadults grow to 70-80mm long. It is a habitat specialist, occurring only\r\nwithin very specific geographic locations. It is naturally rare, with few\r\nrecordings of the species in New South Wales since the 1950s. In\r\nNSW, the Alpine Redspot Dragonfly is restricted to mountainous\r\nregions below 35°S that reach above 600 – 1,800 metres above\r\nsea level. Individuals have extremely specific habitat requirements in\r\nthat they only occur amongst rocks, logs and moss within the splash\r\nzone of waterfalls or in the nearby stream edge.\r\nThey are an endangered species -\r\nhttps://www.dpi.nsw.gov.au/fishing/speciesprotection/conservation/what-current/vulnerable-species/alpineredspot-dragonfly. \r\n\r\nThe methods used to create the predicted current\r\ndistribution of Alpine Redspot Dragonfly are described fully in: NSW\r\nDepartment of Primary Industries (2015), NSW Fish Community\r\nStatus 2015 – Final Report.\r\n\r\nAll available records of the species were collated and assessed for\r\naccuracy. For current distribution, only records after 1 January 1994\r\nwere used. Within the framework of the Australian Hydrological\r\nGeospatial Fabric V2 surface hydrology network, the records were\r\nassociated with attributes from the National Environmental Stream\r\nAttributes Database and River Styles® geomorphology. The\r\nAustralian Hydrological Geospatial Fabric V2 surface hydrology network (Geofabric) is a fully connected and directed stream network\r\nbased a 9 second DEM. It allocates a unique stream segment\r\nnumber to each river reach in Australia. The Environmental\r\nAttributes Database is a set of lookup tables supplying attributes\r\ndescribing the natural and anthropogenic characteristics of the\r\nstream and catchment environment that was developed by the\r\nAustralian National University (ANU) in 2011 and updated in 2012.\r\nThe data is supplied as part of the supplementary Geofabric\r\nproducts which is associated with the 9 second DEM derived\r\nstreams and the National Catchment Boundaries based on 250k\r\nscale stream network. 30 Stream variables were assessed for the\r\nmodelling.\r\n\r\nRiver Styles® provides a high resolution categorical classification of\r\nriver character within a nested hierarchy of criteria based on valley\r\nsetting, channel planform, geomorphic units, and bed material. The\r\nNSW Office of Water compiled a spatial dataset of River Styles®\r\nclassifications for a large number of the waterways of NSW. From 65\r\nRiver Style® categories we generated two new fields representing\r\nPlanform (34 categories) and Substratum (8 categories) for each\r\nstream segment. River Style® planform and substratum categories\r\nwere then assigned to each Geofabric segment.\r\n\r\nMaxEnt 3.3.3 is a widely used species distribution modelling program\r\nthat utilises presence records to generate probabilities of occurrence\r\nbased on a suite of environmental variables quantified across the\r\narea of interest. It was used to model the current geographic\r\ndistribution of each listed threatened freshwater aquatic species or\r\npopulation. We utilised logistic output to plot the predicted\r\ndistribution of each species. This output equates to a probability that\r\nthe species will be observed in each river reach, given the\r\nenvironmental conditions that exist there relative to the\r\nenvironmental conditions where the species is known to occur. For\r\nthis mapping, above 33% probability was considered predicted\r\npresence. In addition, predicted separate populations were\r\nconnected by manual interpretation. The predicted values for each\r\nriver reach were converted from the Geofabric framework to the\r\nhigher resolution 2013 NSW Strahler Stream Order Hydroline.高山红蜻蜓（Alpine Redspot Dragonfly，学名Austropetalia tonyana）是一种中等体型的蜻蜓。幼虫体长可达32-35毫米，成虫体长可达70-80毫米。该物种为典型的生境特化类群，仅分布于极为特定的地理区域。其自然种群极为稀少，自20世纪50年代以来，在新南威尔士州（New South Wales，简称NSW）的有效记录寥寥无几。在新南威尔士州境内，高山红蜻蜓仅局限分布于南纬35°以下、海拔600至1800米的山地区域。该物种对生境有着极为严苛的要求，仅出没于瀑布溅水区周边或邻近溪流岸带的岩石、枯木与苔藓群落中。 该物种属于濒危物种，相关保护信息可查阅：https://www.dpi.nsw.gov.au/fishing/speciesprotection/conservation/what-current/vulnerable-species/alpineredspot-dragonfly。 用于生成高山红蜻蜓当前潜在分布区的建模方法详细记载于：新南威尔士州 primary industries 部（NSW Department of Primary Industries，2015）发布的《2015年新南威尔士州鱼类群落现状——最终报告》。 研究团队收集了该物种的所有现存观测记录，并对其准确性进行了核验。在当前适生分布区建模过程中，仅采用1994年1月1日之后的有效记录。在澳大利亚水文地理空间框架V2（Australian Hydrological Geospatial Fabric V2，简称Geofabric）地表水文网络的框架下，所有有效记录被关联至国家环境溪流属性数据库（National Environmental Stream Attributes Database）以及River Styles®地貌学数据集的属性信息。澳大利亚水文地理空间框架V2地表水文网络是一套基于9秒分辨率数字高程模型（Digital Elevation Model，简称DEM）构建的全连通定向溪流网络，可为澳大利亚境内的每一段河道分配唯一的溪流段编号。国家环境溪流属性数据库是一套属性查找表，用于描述溪流与流域环境的自然及人为干扰特征，该数据库由澳大利亚国立大学（Australian National University，简称ANU）于2011年开发，并于2012年完成更新。该数据作为Geofabric的配套产品提供，配套产品关联了基于9秒DEM生成的溪流图层，以及基于25万比例尺溪流网络绘制的国家流域边界。本次物种分布建模共评估了30个溪流相关变量。 River Styles®是一套基于流域背景、河道平面形态、地貌单元与河床物质的嵌套分级标准，可对河道特征进行高分辨率分类。新南威尔士州水务局（NSW Office of Water）已为新南威尔士州境内大量水道编制了River Styles®分类空间数据集。研究团队从65个River Styles®原始分类中衍生出两个新字段，分别对应河道平面形态（共34个分类）与河床基质（共8个分类），并将这两个字段赋予每一段溪流。随后，将River Styles®的平面形态与基质分类信息关联至每一个Geofabric溪流段。 MaxEnt 3.3.3是一款广泛应用的物种分布建模工具，其通过物种出现记录，基于研究区域内量化得到的一系列环境变量，生成物种在对应区域的出现概率。本研究使用该工具对每一种列入保护名录的淡水濒危水生物种或种群的当前地理分布进行建模。我们采用逻辑回归输出结果来绘制各物种的潜在分布区，该输出结果代表：在某一河道段的环境条件相对于该物种已知出现地的环境条件时，该物种在此处被观测到的概率。本次制图中将出现概率高于33%的区域判定为预测适生区。此外，研究团队通过人工解译将预测得到的独立种群斑块进行空间连接。最后，将Geofabric框架下的各溪流段预测值转换至更高分辨率的2013年新南威尔士州斯特拉勒（Strahler）河道等级水文线图层中。