Urban green space (UGS) is a broad and potentially very inclusive term. Although most discussions on UGS focus on urban parks, there are many other vegetated areas in cities. Many are not formally recognised and protected, hence they are called informal green spaces (IGS), and yet they provide ecosystem services similar to parks. Based on a detailed overview of the different categories of UGS, we shed new light on how the different categories of UGS are included in urban planning and provide a snapshot of the disturbing urban land use transition – from UGS to other uses – which is partly related to the lack of formal recognition of IGS. The novelty in our study is that we mapped and analysed all UGS in our case study area, following two rivers that cut through Lodz (Łódź), Poland – from one peri-urban area (partly rural), through the city centre, to the peri-urban area on the other side of the city. The urban structures and the gradient of buildings in the studied area coincide with the urban structures for the whole of Lodz; therefore, our research area is a representative part of the city and its heterogeneity. Out of the seventeen UGS categories we distinguished, only six are formally recognised and account for 24% of all areas covered by UGS. Only 7% of the area we identified as UGS is designated as different types of vegetated areas according to local zoning plans. The analysis highlights broader challenges related to the planning and management of urban green and blue infrastructures.

城市绿地 (UGS) 是一个广泛且可能非常包容的术语。虽然大多数关于 UGS 的讨论都集中在城市公园，但城市中还有许多其他植被区。许多没有得到正式承认和保护，因此被称为非正式绿地 (IGS)，但它们提供类似于公园的生态系统服务。基于对不同类别 UGS 的详细概述，我们阐明了不同类别的 UGS 如何包含在城市规划中，并提供了令人不安的城市土地利用转变的快照 - 从 UGS 到其他用途 - 这部分是相关的由于缺乏对 IGS 的正式认可。我们研究的新颖之处在于，我们绘制并分析了案例研究区域中的所有地下储气库，沿着两条穿过波兰罗兹 (Łódź) 的河流——从一个城市周边地区（部分农村）穿过市中心，到城市另一边的城郊地区。研究区的城市结构和建筑坡度与整个罗兹的城市结构一致；因此，我们的研究区域是城市及其异质性的代表性部分。在我们区分的 17 个 UGS 类别中，只有 6 个得到正式认可，占 UGS 覆盖的所有区域的 24%。根据当地分区计划，我们确定为 UGS 的区域中只有 7% 被指定为不同类型的植被区。该分析强调了与城市绿色和蓝色基础设施的规划和管理相关的更广泛挑战。我们的研究区域是城市及其异质性的代表性部分。在我们区分的 17 个 UGS 类别中，只有 6 个得到正式认可，占 UGS 覆盖的所有区域的 24%。根据当地分区计划，我们确定为 UGS 的区域中只有 7% 被指定为不同类型的植被区。该分析强调了与城市绿色和蓝色基础设施的规划和管理相关的更广泛挑战。我们的研究区域是城市及其异质性的代表性部分。在我们区分的 17 个 UGS 类别中，只有 6 个得到正式认可，占 UGS 覆盖的所有区域的 24%。根据当地分区计划，我们确定为 UGS 的区域中只有 7% 被指定为不同类型的植被区。该分析强调了与城市绿色和蓝色基础设施的规划和管理相关的更广泛挑战。