BLACK CARBON AND MOLECULAR COMPOSITION OF THROUGHFALL DISSOLVED ORGANIC MATTER FROM 36 TREE SPECIES IN AN URBAN FOREST

Most rain that falls on land is intercepted by a tree canopy, making leaves the first source of dissolved organic matter (DOM) to this water, which mainly drips to the ground as throughfall. While throughfall has been well studied in rural forests, less research has focused on the throughfall of urban trees. This study collected throughfall samples from thirty-six tree species on Northeastern University’s urban campus arboretum in Boston, Massachusetts. The DOM was solid phase extracted and analyzed via Fourier transform ion cyclotron resonance mass spectrometry to define molecular composition and also analyzed for the amount and composition of black carbon using high pressure liquid chromatography. How throughfall black carbon and molecular composition vary with tree species and aspects of the urban environment (e.g., proximity to roads and buildings) are explored. Since some throughfall components are readily consumed by microorganisms, while others, including black carbon, can be stable in the environment for millennia, results will enlighten the downstream effects of trees on urban carbon cycling and water quality. This will enable stakeholders to manage tree planting and maintenance, runoff management, and water quality protection in ways that account for the impacts of trees on the urban environment.

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Primary Presenter: Patrick Milne, Northeastern University (milne.pa@northeastern.edu)

Authors:

Patrick Milne, Northeastern University  (milne.pa@northeastern.edu)

Ayesha Desai, Northeastern University  (desai.ay@northeastern.edu)

Novera Alam, Northeastern University  (alam.n@northeastern.edu)

Jeffrey Agar, Northeastern University  (j.agar@northeastern.edu)

Aron Stubbins, Northeastern University  (a.stubbins@northeastern.edu)