COS 107-7
Citizen science to study urban soils
Citizen science represents an exciting opportunity to reconnect people with the ecosystems they inhabit and to learn about the services ecosystems provide. In an effort to both engage citizen scientists and to study urban soil ecological systems, we have recently initiated a Global Urban Soil Ecological Education Network (GLUSEEN), which when fully implemented will be a worldwide multi-city comparison investigating the effects of urban environments on decomposition and soil community structure. To address the following questions, we have designed a set of relatively inexpensive experiments that can be employed at many locations and engage citizen scientists: 1) What is the response of soil biodiversity and decay rate in urban soils at local, regional and global scales? 2) Do differences in soil biodiversity among urban habitats relate to functional changes in the decomposer subsystem? The set of experiments vary in complexity, cost, and applicability from simple comparisons of litter weight loss over time, to the chemical changes of the litter, to the inclusion of environmental measurements. For decomposition experiments we used commercially available nylon mesh teabags which were presoaked to remove the large amount of soluble material. A pilot study is underway in five cities: Baltimore, (USA), Budapest (Hungary), Helsinki (Finland), Lahti (Finland), and Potchefstroom (South Africa). In each city four habitat types were identified in five replicates: reference (R) reflecting natural vegetation outside the city, remnant patches (RP) of the reference cover within the city, low maintenance lawn (L), and highly disturbed soil (D).
Results/Conclusions
Soil data from Lahti, Helsinki, and Baltimore have already revealed some commonalities. Soil pH varied between 4.8 and 7.1, and increased in the habitat types from R to RP, L, and D. Soil organic matter values were much higher for the R and RP habitat types in Finland than in Baltimore; however, with little difference between the L and D habitats. Significant RP habitat differences occurred for decomposition rates in Lahti between coniferous and deciduous soils (25% and 34% mass loss after six months, respectively). These results demonstrate that commercially-available nylon meshed teabags, when pre-soaked, have the potential to detect differences in biological activity (here decomposition) between habitat types. Moreover, the consistency among commercially-available teabags of the same type (weight, tea leaves) was remarkably high. We conclude that simple teabag decomposition studies are a useful way to both engage citizen scientists and at same time measure differences in soil habitat types in urban landscapes.