Nutrient fertilization by dogs in peri?urban ecosystems

(Semi-)natural ecosystems provide many important benefits to nature and people, but are often located near populated urbanized areas across the globe. During recreational activities, people bring dogs into peri-urban forests nature, their nutrient inputs per unit space time via dog faeces urine remain scarcely quantified. Here, we estimate net fertilization rates of in ecosystems, with a focus on nitrogen (N) phosphorus (P) because evident effects plant biodiversity. We used 487 direct-count censuses over 1.5 years collect accurate abundance data hectare year four sites reserves Belgium. Based estimated densities systematic literature search concentrations faeces, calculate N P from deposits, also propagating uncertainty variability these estimates. find that canine average amount 11 kg (more or less equally faeces) 5 (predominantly year, respectively. These amounts substantial when compared atmospheric extractable traditional management (e.g. mowing hay removal). Our substantial. Such levels may considerably influence biodiversity ecosystem functioning, co-determine restoration outcomes. results underpin need for managers policy makers more (i) consider currently neglected by plans goals, (ii) communicate walkers role as ‘fertilizer’ highlight necessity remove at least solid faecal waste, (iii) sensitive oligotrophic species adapted nutrient-poor soils, establish nearby off-leash parks, enforce use short leashes and/or apply bans such high abundances can be avoided.