A Comparative Approach to Artificial and Natural Green Walls According to Ecological Sustainability

Together with the rapid industrialization of the world, urbanization is also uncontrollably increasing. Such an increase in urbanization exerts the greatest pressure on natural resources, obligating people to live in intense structural spaces and increasing the need for green spaces in cities. Because of the expensive costs of horizontal surfaces being “green”, urban places are faced with serious green-infrastructure problems. In recent years, alternatives have been searched for to eliminate such deficiencies. These alternatives, such as rain gardens, green walls (GWs), ecological designs, and green roofs, are commonly included in urban landscape designs. Besides rocky or steep-slope natural green walls (NGWs), natural green covers over buildings, walls, and so forth, structural members are also encountered in urban or rural places. On the other hand, artificial green walls (AGWs) have recently been used as a significant component of urban design. Although the AGWs are able to address various functional needs, they have not yet gained the desired popularity because of construction costs, static loads, constructional damages, and maintenance costs. In addition, such sites are largely left to exotic species with limited ecological requirements; these species are far from meeting ecological functions and resistance to extreme conditions. This study was conducted for a benchmarking assessment of artificial and natural green walls (A&NGWs) with a high potential in urban landscape design not only for esthetics, but also for ecological and economical purposes. Plant species, initial establishment, maintenance costs, and some other parameters of selected GWs were assessed. The study was considered as pioneering research for low-cost minimum-maintenance AGWs to be included in urban landscape designs. It was concluded, on the basis of the present findings, that the GW systems established with natural plant species, rock, and other materials already existing in natural landscapes could be constructed at fairly low costs, and such wall systems could have great ecological contributions.