Urban church forests for local temperature regulation: Implications the role of managing and incorporating urban green space in urban planning

Urban church forests for local temperature regulation: Implications the role of managing and incorporating urban green space in urban planning

The global surface temperature shows an increment of 0.5±0.1°C per decade and 1.05±0.3°C per century from 1880-2014 with greater increases in cities than non-urban areas. Global communities are shifting towards urbanization due to various factors. Urbanization has caused lack of stable condition for dwellers due to environmental and anthropogenic factors such as land cover changes. Urban temperature rising is the main factors hindering urban dwellers at global level due to insufficient green areas. Social institutions are playing important role in urban greening and urban climate regulation. Ethiopian Orthodox Tewahido Church has long history in indigenous trees biodiversity conservation that plays largely greening role in urban and rural parts of the country. However, there is a research gap in Ethiopia regarding the role of urban green area in the church yards in regulating urban temperature and microclimate change. Therefore, the study evaluated the role of church managed forests in Addis Ababa in regulating surface temperature. Surface temperature inside four church forests at a buffer radius of 0–50 m, 50–100 m, 100–200 m and 200–500 m estimated using Landsat image thermal band 6 of 1986, 2000 and 2010 and ground measurement by ambient thermometer at 10:00 am, 12:30 am and 3:00 pm local time. The ground measurement was done in order to validate satellite image analysis. Plant species diversity, DBH, H, HC, BH and BA was measured. There were 1167 trees in the four studied churches. The mean temperatures of the studied sites were 22.5±0.1, 23.25±0.2, 24±0.6, 24.6±1.1 and 25.5±2.2°C on site,0–50 m, 50–100 m, 100–200m and 200–500 m respectively for 1986 images; 23.2±0.5, 23.3±1.0, 24.3±2.1, 24.8±2.2 and 25.5±1.8°C on site, 0-50 m, 50–100 m, 100–200 m and 200–500 m respectively for 2000 images and 23.2±0.3, 23.27±0.2, 23.7±1.6, 24±1.4 and 24.7±1.3°C on site, 0–50 m, 50–100 m, 100–200 m and 200–500 m respectively for 2010 images. The result illustrated a significant influence of green area on urban temperature in the buffering radius and implies the possibility of regulating urban temperature by planning urban green area in appropriate radius intervals. The study indicated that church forests in particular, social institution and urban green area in general have significant role in urban temperature regulation.