Uniform TitleThe role of soil metal contamination in the vegetative assemblage development of an urban brownfield
NameGallagher, Francis J. (Frank J.) (author), Grabosky, Jason (chair), Smouse, Peter (internal member), Lockwood, Julie (internal member), Weis, Judith (internal member), Shaw, Judith (outside member), Rutgers University, Graduate School - New Brunswick,
SubjectEcology and Evolution,
Soils--Heavy metal content,
Plants--Effects of metals on
DescriptionAnthropogenic sources of toxic elements have seriously compromised the ecological integrity of many green areas in urban landscapes. Analysis of soil samples from a brownfield within Liberty State Park, Jersey City, New Jersey, USA, shows that arsenic, chromium, lead, zinc and vanadium exist at concentrations above those considered ambient for the area. Accumulation and translocation features were characterized for the dominant plant species of four vegetative assemblages.
A comparison of soil metal maps and vegetative assemblage maps indicates that northern hardwoods dominated areas of increasing total soil metal load while semi-emergent marshes, consisting mostly of endemic species were restricted primarily to areas of low soil metal load.
Using both satellite imagery and field spectral measurement we examined plant productivity at the assemblage and individual specimen level. In addition, we studied longer-term growth trends via tree core data (basal area increase). Leaf chlorophyll content within the hardwood assemblage correlated with a threshold model for metal tolerance, decreasing significantly beyond a total soil metal index of 3.5. Biomass production in Betula populifolia (Marsh) (Gray Birch), the co-dominant tree species, demonstrated an inverse relationship with the concentration of Zn in the leaf tissue during the growing season. Incremental basal area growth in B. populifolia also exhibited a reciprocal relationship with soil metal load.
The results of this study also indicate that B. populifolia, employs a strategy whereby different wing loading rates result from variation in size and weight of the seed. The decrease in seed size correlated well with total soil metal load, while the correlation with seed weight was marginal.
All three areas of the study indicate that assemblage development is impacted if not driven by soil metal contamination. Hence, models for vegetative assembly development, at least those associated with contamination gradients within the urban context, should account for these abiotic factors rather than focusing primarily on competition or facilitation between species.
NoteIncludes bibliographical references.
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
RightsThe author owns the copyright to this work.