38
D. A. Gatt and M. C. Mifsud
environment (Kjellgren and Buhrkall 2010), including in the treatment of depression
and anxiety (Barton and Pretty 2010).
2.5 Biodiversity and Physical Health
Several possible mechanisms through which humans benefit from nature have been
proposed, including immune system benefits, reduction of blood glucose levels, and
improved quality of sleep (Kuo 2015). Two of these mechanisms are described below.
Phytoncides are volatile organic compounds (VOCs) secreted by trees and plants,
that repel or combat bacteria, fungi, insects and animals. Research indicates that
phytoncides may assist in reducing the incidence of cardiovascular diseases, boost
immune function, increase natural killer (NK) cell activity, and reduce anxiety (Li
2010; Tsao et al. 2014).
Microbiota—People with allergies who live in areas of low environmental diversity have significantly lower generic diversity of gammaproteobacteria on their skin
when compared to individuals who do not suffer from allergies (Hanski et al. 2012).
These bacteria help protect against allergies and inflammatory disorders, and may
eventually be utilised in the prevention and treatment of allergies (Kaesler et al.
2018).
2.6 Ecosystem Services
The Millennium Ecosystem Assessment Board (MA) (2005) states that ecosystem
services are “the benefits people obtain from ecosystems” (preface, page V).
Studies on human perceptions show that many factors influence the value placed
on ecosystem services, with differences evident between residents in rural and
urban areas, and between countries. The differences could be a result of personal
backgrounds and the ecosystem services required (Lapointe et al. 2019).
The uptake of pollutants and deposition of particulate matter by plants is an essential
ecosystem service (Mori et al. 2018). In the urban environment, pollution-tolerant
trees can sequester several tonnes of carbon annually (Nowak et al. 2018).
Temperature extremes may be mitigated by trees and green roofs, provided correct
planning is utilised (Calcerano and Martinelli 2016). Buildings are thus shaded during
the summer and shielded from cold winds in winter (Laaidi et al. 2014). This, in turn,
reduces energy consumption (Kuronuma et al. 2018).
High Water Quality can be achieved using aquatic species for the cleaning of water
bodies (McLaughlan and Aldridge 2013). Some wastewater treatment systems and
D. A. Gatt and M. C. Mifsud
environment (Kjellgren and Buhrkall 2010), including in the treatment of depression
and anxiety (Barton and Pretty 2010).
2.5 Biodiversity and Physical Health
Several possible mechanisms through which humans benefit from nature have been
proposed, including immune system benefits, reduction of blood glucose levels, and
improved quality of sleep (Kuo 2015). Two of these mechanisms are described below.
Phytoncides are volatile organic compounds (VOCs) secreted by trees and plants,
that repel or combat bacteria, fungi, insects and animals. Research indicates that
phytoncides may assist in reducing the incidence of cardiovascular diseases, boost
immune function, increase natural killer (NK) cell activity, and reduce anxiety (Li
2010; Tsao et al. 2014).
Microbiota—People with allergies who live in areas of low environmental diversity have significantly lower generic diversity of gammaproteobacteria on their skin
when compared to individuals who do not suffer from allergies (Hanski et al. 2012).
These bacteria help protect against allergies and inflammatory disorders, and may
eventually be utilised in the prevention and treatment of allergies (Kaesler et al.
2018).
2.6 Ecosystem Services
The Millennium Ecosystem Assessment Board (MA) (2005) states that ecosystem
services are “the benefits people obtain from ecosystems” (preface, page V).
Studies on human perceptions show that many factors influence the value placed
on ecosystem services, with differences evident between residents in rural and
urban areas, and between countries. The differences could be a result of personal
backgrounds and the ecosystem services required (Lapointe et al. 2019).
The uptake of pollutants and deposition of particulate matter by plants is an essential
ecosystem service (Mori et al. 2018). In the urban environment, pollution-tolerant
trees can sequester several tonnes of carbon annually (Nowak et al. 2018).
Temperature extremes may be mitigated by trees and green roofs, provided correct
planning is utilised (Calcerano and Martinelli 2016). Buildings are thus shaded during
the summer and shielded from cold winds in winter (Laaidi et al. 2014). This, in turn,
reduces energy consumption (Kuronuma et al. 2018).
High Water Quality can be achieved using aquatic species for the cleaning of water
bodies (McLaughlan and Aldridge 2013). Some wastewater treatment systems and