Browsing by Subject "urban remnant forest"

Keeping dogs (Canis familiaris) affects the environment. One significant effect of dogs in the environment is the production and deposition of urine. Unlike other waste, dog urine cannot be easily collected by owners, leading to unfiltered introduction into the soil. Dog urine is high in urea, which hydrolyzes to ammonium and nitrate. These soil nitrogen forms have the potential to change other soil properties that may cause harm in plant or microbial health, and contributing to eutrophication. In this thesis I investigate the impacts of dogs on soil nitrogen properties and their connection with human population density and closeness to walking paths in urban remnant forests. To evaluate the level of impact of dogs and to gain knowledge on the current nitrogen content and δ15N in urban remnant forests, five urban remnant forests were examined. Within each forest, soil nitrogen forms, δ15N in the soil and foliage samples, as well as total carbon and nitrogen content of the soil were compared, besides basic soil properties between dog-affected and control areas. The study revealed elevated levels of soil electrical conductivity, ammonium, and nitrate, as well as soil and foliage δ15N in dog-affected areas. Unexpectedly, soil acidity was lower in samples taken next to paths where dogs can potentially urinate. Organic matter content and total nitrogen and carbon content of the soils were higher where dogs are not frequent visitors, meanwhile the carbon-to-nitrogen ratio was also higher. These findings show that the impacts of dog urine on the soil should be considered in urban planning and further research is needed to understand the significance of it.