Analysis of vegetation from satellite images correlated to the bird species presence and the state of health of the ecosystems of Bucharest during the period from 1991 to 2006

Abstract

The urban vegetation needs adequate monitoring and conservation, being a critical resource of urban landscape. To its deeply esthetic values, the practical values and, respectively, ecosystem services delivered by the urban biodiversity are added (amelioration of the environment and urban microclimate, flood control, diminishing of the environmental pollution, increasing of biodiversity and habitats etc.). Accurate remote sensing techniques have been used widely in locating and mapping urban vegetation (Light Detection And Ranging-LiDAR, satellite images).The purpose of this study is to point out the vegetation status in correlation with the number of the bird species (as indicator of the ecosystem's health), using remote sensing techniques (Landsat satellite images), between 1991-2006 in Bucharest, Romania's capital. Rapid urban evolution of Bucharest led to important changes within the structure of the city, underlined by the increasing of the built area to the detriment of the green one. The intensity of the urbanization rate also led to the decreasing of the number of the bird species. The results obtained through analysis of satellite images indicate the necessity to acquire the up-to-date information related to the vegetation status in order to establish in the future, through urban landscape projects, protection measures for the vegetation cover and for the bird habitats in Bucharest Municipality.

The Importance of Connected and Interspersed Urban Green and Blue Space for Biodiversity: A Case Study in Cork City, Ireland

“…Green space was shown to have a positive relationship with bird diversity, and by contrast, the built class exhibited negative relationships with bird diversity. These relationships were expected as green space was projected to have a positive impact on bird diversity, particularly woody habitat, while built environment was projected to have a negative impact, as has been found in other studies [2,35,71,72]. For example, our research corroborates the findings of Keten et al [71] who developed a riparian quality index to quantify the impact on such habitats on avian biodiversity, identifying that as the proportion of urban cover decreases in riparian habitat and is replaced with more natural green coverage, biodiversity increases.…”

“…A mudflat class was also assigned to the classification scheme to capture the presence of mudflats on the eastern side of Cork City due the importance of mudflats as a habitat for bird diversity. An automatic supervised maximum likelihood classifier was implemented in ENVI5.5 to perform perpixel classification of the study area [35,43,44]. This method assumes that the values for each class in each of the bands are normally distributed and calculates the probability that a given pixel belongs to a specific class defined by training areas.…”

“…These habitats have been found to be vitally important for urban biodiversity [33], and when considered together can form corridors and networks through the often-inhospitable matrix. To overcome this within urban ecosystems, remote sensing is the predominant method used for the identification and classification of UGBS [34][35][36][37][38][39][40][41] and has been identified as a powerful method for uncovering these 'invisible' green spaces in the urban framework. Sentinel-2 is the primary sensor utilized in Europe in recent years due to its wide swatch, frequent revisit time, fine spatial resolution (10 m) and zero cost [42][43][44].…”