Data from: Current and historical land use influence soil-based ecosystem services in an urban landscape

Urban landscapes are increasingly recognized as providing important ecosystem services (ES) to their occupants. Yet, urban ES assessments often ignore the complex spatial heterogeneity and land-use history of cities. Soil-based services may be particularly susceptible to land-use legacy effects. We studied indicators of three soil-based ES – carbon storage, water quality regulation, and runoff regulation – in a historically agricultural urban landscape and asked: (1) How do ES indicators vary with contemporary land cover and time since development? (2) Do ES indicators vary primarily among land-cover classes, within land-cover classes, or within sites? (3) What is the relative contribution of urban land-cover classes to potential citywide ES provision? We measured biophysical indicators (soil carbon (C), available phosphorus (P), and saturated hydraulic conductivity (Ks)) in 100 sites across 5 land-cover classes, spanning an ~125 year gradient of time since development within each land-cover class. Potential for ES provision was substantial in urban green spaces, including developed land. Runoff regulation services (high Ks) were highest in forests; water quality regulation (low P) was highest in open spaces and grasslands; and open spaces and developed land (e.g., residential yards) had the highest C storage. In developed land covers, both C and P increased with time since development, indicating effects of historical land-use on contemporary ES and tradeoffs between two important ES. Among-site differences accounted for a high proportion of variance in soil properties in forests, grasslands, and open space, while residential areas had high within-site variability – underscoring the leverage city residents have to improve urban ES provision. Developed land covers contributed most ES supply at the citywide scale, even after accounting for potential impacts of impervious surfaces. Considering the full mosaic of urban green space and its history is needed to estimate the kinds and magnitude of ES provided in cities, and to augment regional ES assessments that often ignore or underestimate urban ES supply.

城市景观为其居住者提供重要生态系统服务（Ecosystem Services, ES）的价值，正日益得到广泛认可。然而，当前的城市生态系统服务评估往往忽略了城市复杂的空间异质性与土地利用历史。基于土壤的生态系统服务尤其易受土地利用遗留效应的影响。本研究在一处具有农业开发历史的城市景观中，针对三类基于土壤的生态系统服务指标——碳储存、水质调节与径流调节——展开研究，并提出以下三个问题：(1) 生态系统服务指标如何随当代土地覆被类型以及开发时长发生变化？(2) 生态系统服务指标的差异主要存在于土地覆被类别之间、同一土地覆被类别内部，还是样地内部？(3) 各类城市土地覆被类型对城市全域潜在生态系统服务供给的相对贡献度如何？本研究在覆盖5类土地覆被类型的100个样地中测定了三项生物物理指标：土壤碳（soil carbon, C）、有效磷（available phosphorus, P）以及饱和导水率（saturated hydraulic conductivity, Ks），且每类土地覆被类型的样地均覆盖了约125年的开发时长梯度。城市绿地（包括已开发用地）的生态系统服务供给潜力十分可观。径流调节服务（高饱和导水率）在森林中表现最优；水质调节服务（低有效磷含量）在开阔空地与草地中表现最佳；而碳储存能力则在开阔空地与已开发用地（如住宅庭院）中最为突出。在森林、草地与开阔空地中，土壤性质的变异主要源于样地间差异，而住宅区的土壤性质则表现出较高的样地内变异——这凸显了城市居民在提升城市生态系统服务供给能力方面的重要作用。即便考虑到不透水地表的潜在影响，已开发土地覆被类型仍是城市全域生态系统服务供给的主要贡献者。若要准确估算城市所提供的生态系统服务类型与规模，并完善那些往往忽略或低估城市生态系统服务供给的区域生态系统服务评估工作，就必须充分考量城市绿地的完整镶嵌格局及其开发历史。