Urban residents and their pets utilize urban greenspaces daily. As urban dog ownership rates increase globally, urban greenspaces are under mounting pressure even as the benefits and services they provide become more important. The urine of dogs is high in nitrogen (N) and may represent a significant portion of the annual urban N load. We examined the spatial distribution and impact of N deposition from dog urine on soils in three urban greenspace typologies in Finland: Parks, Tree Alleys, and Remnant Forests. We analyzed soil from around trees, lampposts and lawn areas near walking paths, and compared these to soils from lawn areas 8 m away from pathways. Soil nitrate, ammonium, total N concentrations, and electrical conductivity were significantly higher and soil pH significantly lower near path-side trees and poles relative to the 8 m lawn plots. Also, stable isotope analysis indicates that the primary source of path-side N are distinct from those of the 8 m lawn plots, supporting our hypothesis that dogs are a significant source of N in urban greenspaces, but that this deposition occurs in a restricted zone associated with walking paths. Additionally, we found that Remnant Forests were the least impacted of the three typologies analyzed. We recommend that landscape planners acknowledge this impact, and design parks to reduce or isolate this source of N from the wider environment.

中文翻译：

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狗尿对城市绿地土壤化学有严重影响

城市居民和他们的宠物每天都在利用城市绿地。随着全球城市养狗率的增加，城市绿地面临越来越大的压力，即使它们提供的好处和服务变得更加重要。狗的尿液中的氮 (N) 含量很高，可能占每年城市 N 负荷的很大一部分。我们研究了芬兰三种城市绿地类型中狗尿中氮沉积对土壤的空间分布和影响：公园、树巷和残余森林。我们分析了树木周围、路灯柱和人行道附近草坪区域的土壤，并将这些与距离路径 8 m 的草坪区域的土壤进行了比较。土壤硝酸盐、铵、总氮浓度、与 8 m 草坪地块相比，路旁树木和电线杆附近的电导率显着升高，土壤 pH 值显着降低。此外，稳定同位素分析表明路径侧 N 的主要来源与 8 m 草坪地块不同，支持我们的假设，即狗是城市绿地中 N 的重要来源，但这种沉积发生在限制区域与步行路径有关。此外，我们发现在所分析的三种类型中，残余森林受到的影响最小。我们建议景观规划者承认这种影响，并设计公园以减少或隔离这种氮源与更广泛的环境。支持我们的假设，即狗是城市绿地中氮的重要来源，但这种沉积发生在与步行路径相关的限制区域。此外，我们发现在所分析的三种类型中，残余森林受到的影响最小。我们建议景观规划者承认这种影响，并设计公园以减少或隔离这种氮源与更广泛的环境。支持我们的假设，即狗是城市绿地中氮的重要来源，但这种沉积发生在与步行路径相关的限制区域。此外，我们发现在所分析的三种类型中，残余森林受到的影响最小。我们建议景观规划者承认这种影响，并设计公园以减少或隔离这种氮源与更广泛的环境。