128 Ecology and Applied Environmental Science
of studies have proposed measures for hygiene, ventilation and changes in
ways of managing and cleaning buildings.
6.8 grEEn and oPEn SPacES
The existence of green spaces in the city has its roots in the utopian dream
urban populations have of regaining their lost contact with nature. An
extreme consequence of this tendency would be the abolition of cities,
the deurbanisation promised by philosophers and revolutionaries. Proper
town planning, including abundant green and open spaces, can be considered a functional compromise, although it entails substantial costs for
city dwellers, especially when it is carried out a posteriori. One characteristic example is Paris, where Haussmann, prefect during the reign of
Napoleon III, mercilessly tore down thousands of houses between 1853
and 1869 and built 24 squares and broad avenues.
Green and open spaces serve mainly as recreation areas for city dwellers .
They make living in cities more pleasant for various reasons, including
the following:
• Better microclimate
• Aesthetic enjoyment
• Less noise
• Cleaner air
Pollution reduction in such spaces is due not so much to the vegetation,
but rather to lower concentrations of polluting activities, resulting in fewer
emissions of pollutants. Moreover, production of oxygen by vegetation in
the city is of little significance, since on one hand its quantities are negligible, and on the other city air is renewed via air currents. The concentration
of oxygen remains stable (21%) in the air of both cities and countryside;
it is related to the stability of the oxygen cycle (Chapter 4). Another important role played by green spaces is their contribution to the presence of wild
plants and animals in cities. A substantial number of species of the wild
flora and/or fauna adapt to and develop in the built environment and are
favoured by the existence of green spaces.
6.8.1 the Periurban natural Environment
The city is strongly influenced by the periurban natural environment, with
which it is in constant interaction. Periurban forests in particular play a
decisive role in the functioning of the city, because they may:
• Be important recreation areas
• Play a part in regulating the water cycle
of studies have proposed measures for hygiene, ventilation and changes in
ways of managing and cleaning buildings.
6.8 grEEn and oPEn SPacES
The existence of green spaces in the city has its roots in the utopian dream
urban populations have of regaining their lost contact with nature. An
extreme consequence of this tendency would be the abolition of cities,
the deurbanisation promised by philosophers and revolutionaries. Proper
town planning, including abundant green and open spaces, can be considered a functional compromise, although it entails substantial costs for
city dwellers, especially when it is carried out a posteriori. One characteristic example is Paris, where Haussmann, prefect during the reign of
Napoleon III, mercilessly tore down thousands of houses between 1853
and 1869 and built 24 squares and broad avenues.
Green and open spaces serve mainly as recreation areas for city dwellers .
They make living in cities more pleasant for various reasons, including
the following:
• Better microclimate
• Aesthetic enjoyment
• Less noise
• Cleaner air
Pollution reduction in such spaces is due not so much to the vegetation,
but rather to lower concentrations of polluting activities, resulting in fewer
emissions of pollutants. Moreover, production of oxygen by vegetation in
the city is of little significance, since on one hand its quantities are negligible, and on the other city air is renewed via air currents. The concentration
of oxygen remains stable (21%) in the air of both cities and countryside;
it is related to the stability of the oxygen cycle (Chapter 4). Another important role played by green spaces is their contribution to the presence of wild
plants and animals in cities. A substantial number of species of the wild
flora and/or fauna adapt to and develop in the built environment and are
favoured by the existence of green spaces.
6.8.1 the Periurban natural Environment
The city is strongly influenced by the periurban natural environment, with
which it is in constant interaction. Periurban forests in particular play a
decisive role in the functioning of the city, because they may:
• Be important recreation areas
• Play a part in regulating the water cycle