Urban rewilding initiatives are gaining traction in cities, yet little remains known about the spatial opportunities for transitioning greenspaces into rewilding sites. This paper advances a process-oriented framing of urban wild nature areas (WNAs) and proposes a novel methodological approach for mapping existing WNAs at the city-scale, thereby shedding light on the potentials for urban rewilding across greenspace types and urban environments. Using Vienna as a case study, we identify WNAs as greenspaces predominantly shaped by natural succession processes and devoid of vegetation management. NDVI timeseries derived from Sentinel-2-satellite data for the period 2017–2022 are processed using a Random Forest algorithm to distinguish between unmanaged and managed vegetation annually and integrated into a multi-year composite map of ‘urban vegetation management intensity’. Based on this map and a set of objective cut-off values, 1298 WNAs are identified, representing 29.5 % of the city’s total urban greenspace and 14.9 % of the city’s total area. WNAs are distributed across diverse urban settings and greenspace types, with the majority being found in formal greenspaces such as forests, meadows and parks, and low-density built-up areas. The key strength of the process-oriented approach lies in its ability to detect WNAs dominated by natural succession, regardless of historic origin, greenspace type, and governance structure, thereby providing a baseline against which the full potential for urban rewilding can be evaluated. We demonstrate the methods’ utility in identifying potentials for urban rewilding, emphasising the importance of directing rewilding efforts towards residential greenspaces, urban parks, and street greenery, especially in densely built inner-city districts.

中文翻译：

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绘制野生自然区域图以确定城市再野化的优先区域：一种以过程为导向的方法


城市再野化计划在城市中越来越受欢迎，但人们对将绿地转变为再野化地点的空间机会知之甚少。本文推进了城市野生自然区域 （WNA） 的面向过程的框架，并提出了一种在城市规模绘制现有 WNA 的新方法，从而阐明了跨绿地类型和城市环境的城市再野化的潜力。以维也纳为案例研究，我们将 WNA 确定为主要由自然演替过程塑造且缺乏植被管理的绿地。从 2017-2022 年期间的 Sentinel-2 卫星数据得出的 NDVI 时间序列使用随机森林算法进行处理，以每年区分未管理和托管的植被，并整合到“城市植被管理强度”的多年复合地图中。根据此地图和一组客观临界值，确定了 1298 个 WNA，占该市城市总绿地的 29.5% 和城市总面积的 14.9%。WNA 分布在不同的城市环境和绿地类型中，其中大多数位于森林、草地和公园等正式绿地以及低密度建筑区。以过程为导向的方法的关键优势在于它能够检测以自然演替为主的 WNA，无论历史起源、绿地类型和治理结构如何，从而提供一个基线，据此可以评估城市再野化的全部潜力。 我们展示了该方法在确定城市再野化潜力方面的效用，强调了将再野化工作引导到住宅绿地、城市公园和街道绿化的重要性，尤其是在建筑密集的内城区。