Carbon stock of green spaces in central schools of Santiago City, Isabela, Philippines

Green spaces are those areas planted with trees. These areas are very important especially in sequestering carbon. Thus, this study was conducted to determine the amount of carbon stock in the green spaces of 4 central schools in Santiago City, Isabela, Philippines. The study used the measurement of trees at diameter at breast height (dbh). Above-ground biomass was also computed using allometric equation. Interviews using a structured questionnaire was also conducted for the information on the management of trees within the schools. Results showed that among the 4 central schools, Santiago South has the most number of trees with 260 trees with 10 cm dbh and above and with carbon sequestered of 302,310.65 kg. It was followed by Santiago North with 241 trees and with carbon sequestered of 225,920.27 kg; Santiago East with 240 trees with carbon sequestered of 208,621.23 kg; and Santiago West with 67 trees and with 18,587.22 kg of carbon sequestered. The 4 central schools stored a total of 755,439.37 kg or 755.44 tons of carbon. Trees identified in the schools were mahogany (Swietenia macrophylla) with the highest number of individual trees, followed by yemane (Gmelina arborea), narra (Pterocarpus indicus), talisai (Terminalia catappa), and banaba (Lagerstroemia speciosa). In terms of tree management within the schools, teachers and utility workers were interviewed. Based on the findings, most of the respondents have limited knowledge on carbon stocks of green spaces in the schools. However, they took care of the trees by watering, application of fertilizers, and placing tree guards during seedlings transplanting operation. As part of the silvicultural treatments, diseased and defective trees were cut to give way for the healthy trees to grow vigorously. Trees were planted within the school because of the shade and the cooling effect they provide. The schools depend on the seedlings provided by the City Environment and Natural Resources Office for their greening program. Results of the study presents the need for the provision of relevant information on the crucial role of trees and green spaces in carbon sequestration.