Patricia Perelman

Use of tree bark for comparing environmental pollution in different sites from Buenos Aires and Montevideo

Multi-elemental profiles in bark of green ash trees collected in three representative areas of Buenos Aires, Argentina and Montevideo, Uruguay, were assessed as potential air pollution indicators. Ten elements: Al, Ba, Cr, Cu, Fe, Mg, Mn, Ni, Pb, and Zn, were measured using inductively coupled plasma optical emissions spectrometry from 70 samples collected in different environments: central, residential and rural (reference site), in order to compare spatial patterns of metal concentration. The samples used as a control were collected from a nature reserve situated far away from any significant influences, not even a nearby road. The reference site (RF) exhibited the lowest concentrations of Al, Cr, Fe, Ni, Pb, and Zn. However, Ba and Mn showed similar concentrations in all measured sites. Magnesium is the only element that had a greater concentration in RF than at the other sites. Copper did not show any clear pattern. The Centre of Montevideo (MVD) showed higher concentrations of Al, Ba, Cr, Fe, Pb and Zn than the Centre of Buenos Aires (BA). In the A sectors, Montevideo (SAMVD) showed higher concentrations of Al, Cu, Mg, Ni, and Zn and lower concentrations of Ba, Cr, Fe, Mn, and Pb than Buenos Aires (SABA). In the B sectors, Montevideo (SBMVD) showed higher concentrations of Al, Ba, Cu, Fe, Pb, and Zn and lower concentrations of Cr and Mg than Buenos Aires (SBBA), but similar concentrations of Mn and Ni. The use of bark for biomonitoring metals allowed us to detect concentration differences related to the urban fabric and the different kinds of vehicles and their fuels. In the cities, the differences in metal concentrations detected in bark were more striking between the sectors than between centers, despite CBA being much larger than CMVD in population, extension and vehicular traffic.

Use of visitors’ perception in urban reserves in the Buenos Aires metropolis

Urban nature reserves (UR’s) fulfill unique functions for society and are irreplaceable, satisfying human needs particularly in urban and periurban areas. The aim of this paper was to use a perception based approach to analyze whether the urban nature reserves in the metropolitan area of Buenos Aires, Argentina were principally used by visitors according to their main conservation mission. Five hundred written surveys designed to evaluate users’ profile and their perceptions of the selected reserves were conducted during the summer of 2009 to visitors selected at random. Collected data was analyzed by multivariate analyses. The results discriminated two groups (1 and 2) of reserves showing that people chose to visit a nature reserve for two contrasting motivations: the contemplation of nature (group 1) or active recreation (group 2). Both groups of reserves, the respondents participated in environmental programs. All respondents knew about plants whereas knowledge of the fauna was related to the visitors’ level of education. In all reserves respondents considered that nature enhance the quality of human life in the first place, and valued biodiversity en second place. Visitors in group 1 considered nature as very important, while respondents in group 2 thought that is important as a place for having fun. Our findings can potentially assist administrators to understand better how visitors perceive the reserves.