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Sustainable cities: contributions from urban forestry

Sustainable cities: contributions from urban forestry

Great problems afflict our countries, among them we can mention institutionalized corruption, violation of human rights, loss of faith in institutions, among others. No less important are the problems of climate change, loss of biodiversity and in cities the scarcity of green infrastructure (vegetation) is increasing in a worrying way due to the growth of gray infrastructure (cement), urban violence, exacerbated individualism, diseases caused by pollution. environmental, among others. Although we are won over by problems, it is important that we do not lose our ability to propose and our ability to provide creative alternatives for transformative responses.

One of the ways to contribute to the construction of sustainable cities is from urban forestry. Many are the benefits of forests and trees but we have not paid due attention to them. Table 1 shows the potential benefits of urban forests. It is possible to affirm that the establishment of forests in cities is also one of the ways to contribute to sustainable cities and, in general, to the Sustainable Development Goals.

BOX 1. Potential benefits of urban forests

Urban aspectsPotential benefits of urban forests
Food safetyFood supplies, clean water and firewood
Urban povertyCreate jobs and increase income
Soil and landscape degradationImprove soil conditions and prevent erosion
Biodiversity reductionPreserve and increase biodiversity
Air and noise pollutionRemove pollutants from the air and act as an acoustic barrier
Greenhouse gas (GHG) emissionsSequester carbon and mitigate climate change, improve local climate and build resilience
Extreme weather eventsMitigate local climate and build resilience
Energy shortageSave energy through shading / cooling and increase woody fuel availability
Heat island effectRefreshes the built environment with shade and evapotranspiration
Access limited to green areasProvide greater access to natural and green areas
Public healthImprove the physical and mental health of residents
FloodsMitigate runoff and attenuate floods
Unlimited Recreational OpportunitiesProvides opportunities for recreation and environmental education
ExpositionThey offer shelter
Limited water resourcesAllow infiltration and reuse of wastewater
Lack of community and social cohesionOffer private places for formal and informal outdoor interaction

Source: Salbitano et al. (2017).

In addition to the well-known effects of vegetation on mitigation and adaptation to climate change, it is interesting to highlight its effects on health. Thus, based on scientific information, the DKV Institute for Healthy Living (2017) points out that forests improve perceived health and quality of life, reduce morbidity, decrease mortality, reduce overweight and obesity, help maintain cardiovascular health, contribute to health, have a supportive effect and social cohesion that contributes to well-being, and has a co-therapist effect. FAO (2016) states that spending time near trees improves physical and mental health by increasing energy levels and speed of recovery, while lowering blood pressure and stress.

It then means that one of the ways to contribute to creating healthier environments, both personally and socially, is by establishing green areas. In the background, it is a way of fostering a reunion with our essence as we come from nature, we depend on nature and we ourselves are nature. Now we already know that plants, although they do not have nervous systems and organs similar to humans, have equivalent structures by which plants communicate, have sensitivity, react to stimuli and degrees of intelligence to accommodate their metabolism to environmental conditions. In cities with so much violence we need to incorporate sensitivity, beauty, inspiration and sense of unity with nature for an expansion of the consciousness of brotherhood with humans and non-humans.

Incorporating trees and shrubs is not just introducing vegetation. It is also important to consider that this is introducing natural history, personal or collective history motifs. It is to give students of all educational levels the possibility of having study material not only for biology and ecology but other subjects related to natural and social sciences and their interactions, as well as favoring the development of multiple intelligences and interdisciplinary studies. Trees and forests as living schools. For example, the use of the cinchona tree (Cinchona officinalis) to give a sense of national identity, or the use of cicas and Ginko biloba to account for living plant fossils.

In this sense, we propose to carry out or update an inventory of trees and shrubs in the cities for their better management. Now it is more feasible to carry out a diagnosis both because there is technology available that facilitates this work and because of the interest of universities, research centers, clubs and environmental networks willing to carry out this work if a leadership emerges that could well be in charge of the Environmental Managements of the Municipalities. The main variables to consider are:

Code: identification to facilitate registration in geographic information systems and computer database.

Species: scientific name, technical name.

Sowing or planting date(in the case of newly established seedlings)

Location: Geographical coordinates, streets

Location type:In retreats, on berms, in parks, in groves.

Forestry:Trunk diameter, current plant height, predicted plant height, current crown diameter, projected crown diameter.

Phytosanitary status: healthy, sick, presence of fungi

Driving: requirement of pruning, fertilization, others.

Observations: Reduced space for development on paths, roots that lift the paths, authorized replacement for death, danger of falling, branches crossing cables, etc.

Once the inventory of trees and shrubs has been carried out, the design of increasing the forest cover takes into account the following considerations:

  • Forecast on the irrigation system.
  • Use of species with greater resistance to water scarcity (especially in the case of desert areas such as Lima).
  • Take care that the projected, root and crown growth does not affect infrastructure or wiring.
  • Take care that the architecture of the individual or associated vegetation does not constitute a danger to personal and institutional safety.
  • Provision for plant supply that contributes to the diversification of biodiversity (many of the species used are exotic and it is necessary to open up the native flora).
  • Take into account that the type of vegetation is going to be a fauna attractor. Favor vegetation that attracts friendly fauna.
  • Take provisions for the management and maintenance of vegetation.
  • Take into account, depending on the conditions, the use of deciduous species (with the capacity to renew leaves) or perennials.

In order for the vegetation to have a multiple use, consider:

  • Use of species for food purposes for both humans and animals (contribution to food security).
  • Use of species for medicinal purposes (especially for leaves, flowers or fruits)
  • Use of species for ornamental purposes (trees with an abundance of flowers).
  • Use of species with better capacities for absorbing noise and pollutants.

Some thematic motif ideas for greenery arrangements can be:

  • Threatened plants of a region or country (Colles, Polylepis).
  • Emblematic species of regions (Algarrobo de la costa, chestnut tree of the southeastern Amazon)
  • Plant families.
  • Manchales with diversity of species of a certain genus.
  • Malls with plants of uniform defloration or spots as the case may be.
  • The Amazon palm trees.
  • Malls made up of fruit trees.
  • Sacred trees (to account for the cultural wealth of our peoples).
  • Granlongevity trees
  • Trees of the world (to create a sense of planetary identity)
  • Trees with complex architectures such as mangroves or ficus from the Amazon.

As we can appreciate the possibilities are endless. Opportunity to display landscaping where beauty, creativity and inspiration converge. This is an alternative proposal to cement works that are renewed every time only with the desire to mention that work is being done. The municipalities and their population have (we have) the opportunity to make a difference by making large green infrastructure projects contributing to mitigation and adaptation to climate change, to have greater natural and social resilience, to generate more inspiring environments and social cohesion. In short, to contribute to sustainable societies and more sustainable cities.

By: Rodrigo Arce Rojas

Bibliographic references:

DKV Institute for Healthy Living. (2017). Forest baths, a health proposal Special edition 2017. Barcelona: DKV Institute for Healthy Living and the Global Health Institute. Available at: https://www.terra.org/sites/default/files/data/observatorio_bosques.pdf

Food and Agriculture Organization of the United Nations (FAO) (2016). Benefits of urban trees. Rome: Food and Agriculture Organization of the United Nations. Available at: http://www.fao.org/resources/infographics/infographics-details/es/c/411598/

Salbitano, F., Borelli, S., Conigliaro, M. and Chen, Y. Guidelines for urban and peri-urban forestry, by Guidelines for urban and peri-urban forestry, FAO Study: Montes No. 178, Rome, FAO. Available at: http://www.fao.org/3/b-i6210s.pdf

Video: Urban forests and the transformation of cities, Part Two. Sustainable Energy (October 2020).