Abstract
AbstractThis study investigated the distribution and the tree canopy cover (TCC) of the two most prominent street trees (Jacaranda mimosifolia and Platanus × acerifolia) in Johannesburg, using the multispectral SPOT 6 satellite data and field survey GPS points. The importance of the spectral bands (Blue, Green, Red and NIR) and the NDVI index in discriminating between the tree species was quantified using five separability indices (Divergence, Bhattacharyya, Transformed Divergence, Jeffries-Matusita and M-statistic). The visual comparison of the Blue band and the NDVI histograms between the two species and other vegetation type showed the lowest feature overlap, suggesting the highest separability between paired classes. This was further supported by the highest Divergence value for the Blue band (3.68) and NDVI index (2.48) followed by the M-statistic (0.8 and 0.73, respectively) indicating good to moderate separability between the two species, respectively. The results were also consistent with the RF classification where the Blue band and NDVI index were the most important variables for the discrimination between the two species with an overall accuracy of 88% (kappa = 8). The TCC of J. mimosifolia and P. × acerifolia constituted 38% of the total vegetation cover in the city. These findings not only would help prioritize the increase of targeted vegetation cover in low cover areas, but will also provide a valuable information for assessment and protection of vulnerable species such as P. × acerifolia from the threat of the polyphagous shot hole borer, Euwallacea fornicatus in Johannesburg.
Funder
University of the Witwatersrand, Johannesburg
Publisher
Springer Science and Business Media LLC
Reference58 articles.
1. Lawrence, H. In City Trees: A Historical Geography from the Renaissance through to the Nineteenth Century (Charlottesville and London: University of Virginia Press, 2006, Lewis Mumford. The City in History: Its Origins, Its Transformations and Its Prospects (San Diego: Harvest Book Harcourt, 1961).
2. Frawley, J. Campaigning for street trees, Sydney botanic gardens, 1890s–1920s. Environ. Hist. 15(3), 303–322. https://doi.org/10.3197/096734009X12474738199953 (2009).
3. Seburanga, J. L., Kaplin, B. A., Zhang, Q.-X. & Gatesire, T. Amenity trees and green space structure in urban settlements of Kigali, Rwanda. Urban. For. Urban Green. 13(84–9313), 84–93. https://doi.org/10.1016/j.ufug.2013.08.001 (2014).
4. Wilson, E. H. Northern trees in southern lands. J. Arnold Arbor. 4(2), 61–90 (1923).
5. Gwedla, N. & Shackleton, C. M. Population size and development history determine street tree distribution and composition within and between Eastern Cape towns, South Africa. Urban. For. Urban. Gree. 25, 11–18. https://doi.org/10.1016/j.ufug.2017.04.014 (2017).
Cited by
4 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献