Urban vegetation can have beneficial effects on biodiversity and human health and has been widely studied in temperate cities. The situation, however, is different in the tropics: there is a knowledge gap describing the influence of the growth and expansion of tropical cities on vegetation within the cities. There is also a scarcity of work discussing appropriate methods to quantify urban vegetation in the tropics, where financial resources for research are normally quite limited. Our objectives in this article were to measure the amount of urban vegetation in a tropical city, its relationship to population and infrastructure, and to determine if satellite results differ from those obtained on the ground. For these objectives we studied the city of Heredia, Costa Rica, during the rainy season, when vegetation was most developed. We sampled 91 sites from the ground (with 360 degree digital panoramic photographs) and compared the measurements with the corresponding satellite photographs. Satellite and ground estimates of vegetation and infrastructure differed significantly (Kruskal-Wallis ANOVA, p=0.00002). The satellite estimate of vegetation was nearly one third higher that the ground estimate. These finding illustrated that a significant part of the vegetation is hidden from the view, reducing the potential beneficial effects that a person’s perception of plants has on their psychology. Conversely, the estimate of infrastructure cover was much higher from the ground than in the satellite photographs. In the ground estimate the dominant landscape component was vegetation (48%), followed by buildings (28%), roads (23%) and billboards (0.41%). We conclude that density of the human population, rather than its total size, is the best predictor of vegetation in this tropical landscape (multiplicative model regression, F Ratio 7.33, p= 0.0081).
Monge-Najera, Julian; Barrientos, Zaidett; and Zúñiga-Solís, Maribel
"A Satellite and Ground Evaluation of Urban Vegetation and Infrastructure in the Landscape of a Tropical City: Heredia, Costa Rica,"
Cities and the Environment (CATE):
1, Article 12.
Available at: http://digitalcommons.lmu.edu/cate/vol6/iss1/12