Presentation on theme: "The grass is always greener (than the forest): is it the N? Hannah Tremblay Carleton College, 2014."— Presentation transcript:
The grass is always greener (than the forest): is it the N? Hannah Tremblay Carleton College, 2014
Background Fertilization and fossil fuels have more than doubled amount of available N in biosphere Expansion of suburbs is one of the fastest growing land uses Recent evidence suggests that urban soils may be a sink for atmospheric N (Raciti et al. 2008)
The experiment To quantify the differences in total soil nitrogen, available nitrate, and nitrification rates between residential lawns and forested areas in northern New Hampshire. How does the land use shift from forests to lawns affect nitrification and mineralization rates?
Methods: site selection 12 clusters 58 sites Personal interview and questionnaire
Methods: In the field 5 volumetric, 5.8cm diameter, 15cm deep cores from lawns and adjacent forests Vegetative cover and tree inventory recorded Measured area of property
Methods: In the lab Soil sieved and homogenized Two 20 gram subsamples ▫“Time 0” extraction: placed in a 250 ml Nalgene bottle with 100ml of 2M KCl. Settled for 24 hours. ▫“Time final” extraction: incubated for 21 days in a 1 pint mason jar and fanned every 3 days. Soil samples filtered and analyzed