Use of Vegetation as Biomaterial for Controlling Measures of Human Impact on the Environment

Table 2

Functions of vegetation in green walls.

Function	Typology	Description
Aesthetic and protective function	Aesthetic improvements	Especially, green walls provide aesthetic stimulation where it would not otherwise be found. They can also serve to create privacy limiting the negative psychological effects associated with property demarcation.
	Building structure protection	Temperature fluctuations over a building’s lifetime can determine damages in building facades. Green walls provide an additional layer of exterior insulation limiting thermal fluctuations. Furthermore, green walls protect exterior finishes from UV radiation and rain and decrease the effect of wind pressure [36].
Environmental	Noise reduction	The vegetated surface provided by green walls and roofs will block high-frequency sounds, and when constructed with a substrate or growing medium support, it can also block low-frequency noises.
	Increased biodiversity	Green walls can help mitigate the loss of biodiversity due to the effects of urbanization, help sustain a variety of plants, pollinators, and invertebrates, and provide habitat and nesting places for various bird species.
	On-site wastewater treatment	Several water-recycling systems can be applied to green walls. As an example, systems pump greywater through a green wall, which then passes through filters, gravel, and marine plants and treat water which is then sent to a greywater holding tank for household or irrigation use or released into the public water treatment system [37].
	Improved energy efficiency	Green walls can reduce the temperature fluctuations at a wall's surface from a range of 10–60°C to one of 5–30°C, limiting the movement of heat between building walls [38].
	Reduction of the urban heat island effect	The reintroduction of vegetation into urban environments promotes the occurrence of natural cooling processes, such as photosynthesis and evapotranspiration.
	Improved exterior air quality	Green walls mitigate air pollution levels by lowering extreme summer temperatures through photosynthesis, trapping particulate matter, and capturing gases.