Delivery boy motorcycle Pedro Carvalho, due to his profession, usually rides all over Belém. He says that, in the city center, where there is plenty of mango and other species of trees, he feels the heat is milder during the day, however, peripheral areas suffer in this regard. “On Arthur Bernardes Ave, for example, we get scorching sun, and on Augusto Montenegro too. There are few trees and it is much hotter, there is no shade”, he laments.
Carvalho observes from the frontal area of a shopping mall on Avenida Centenário, a sapling planting action carried out by the team from the Secretaria Municipal de Meio Ambiente de Belém (Semma) [Belém Municipal Department of the Environment]. “Belém needs to invest in what people are doing here, it is a way of valuing the environment. The more shade, the greener and the better for us,” he says. The action witnessed by the delivery boy is part of a project launched in January by Semma, called “Green City”, which aims to make the capital of Pará even greener.
According to agricultural engineer Junior Melo, head of the Divisão de Manutenção de Áreas Verdes Públicas [Public Green Areas Maintenance Division] at SEMMA, the planting of seedlings on Centenário Ave should form a small forest to create greater thermal comfort in the area. “We are planting some tree species here with the aim of bringing environmental benefits to the population. Bringing more humidity, lowering the temperature and also making it look more aesthetically pleasing,” he points out.
Melo explains that, as a short-term work plan, Semma is investing in open areas, such as the Centenário flowerbed. “In green areas like this, with permeable soil, we just need to dig a hole and plant. So, we already have these areas mapped out, such as squares, the Daniel Berg viaduct, and the Entroncamento [crossroad], places where we have already planted some species,” he says.
AFFORESTATION INDEX
According to Junior, the next step will be to spread the planting program to the outskirts as well. “But in these places, we have a physical impediment, because they are concreted and paved areas. So, there, we will need a slightly more challenging strategy, which is to break up concrete, dig holes, and then allow things to evolve”, he ponders.
“Belém is considered as one of the capitals with the lowest afforestation rates, and we want to change that reality. We know, and one doesn’t even need to have a technical perspective, to attest that neighborhoods considered more upscale are greener, while the outskirts have always suffered from this problem. That's where we most need to bring thermal comfort to the population", he points out.
Melo guarantees that the Cidade Verde project [Green City] will be an ongoing action, which will not only plant new seedlings, but also manage those that have already been planted to ensure long-term benefits. "Our goal is to plant two thousand seedlings per month so that, by the end of the year, we will have a significant amount of wooded areas", he adds.
Trees in Belém require emergency action
In 2025 alone, Belém has already recorded the fall of at least 16 trees, due to aging, lack of monitoring and the effects of climate change. In 2024, there were 46 falls. Many are centuries-old species that need care to remain standing in the urban environment.
According to an assessment carried out by Semma, there are 47 trees in Belém that require urgent intervention. Of these, 27 are at imminent risk of falling. “We have already mapped some neighborhoods, where there is a greater concentration of these older species, and now we are managing these trees, either with conduction pruning [to keep the plant in a certain line], lowering or even suppression, when we identify that the plant is at risk of falling or is, effectively, already dead and needs to be removed. This will also be an ongoing action”, he explains.
SPECIES
The agronomist points out that the planting program seeks to diversify the species. In the Centenário seedbed, for example, ipê-rosa, mamorana and ipezinho-de-jardim have been planted. This species sellection take into consideration the Manual de Orientação Técnica de Arborização Urbana de Belém [Technical Guidance Manual for Urban Afforestation] in Belém, elaborated in 2013 by Semma in partnership with the Empresa Brasileira de Pesquisa Agropecuária (Embrapa) [Brazilian Agricultural Research Corporation] Eastern Amazon.
“But, in addition, there is a technical committee, including the participation of Embrapa, UFRA [Federal Rural University of the Amazon] and other entities, that will update this manual, which is already outdated. Many years have passed, today we experience a different reality from that of 2013, due to climate change and the understanding that cities need to be resilient”, ponders Melo.
Forestry engineer Noemi Vianna, from Embrapa, was one of the specialists who participated in the preparation of the Manual, in a process that began in 2008, which involved several groups and workshops, public hearings and culminated in the Municipal Urban Afforestation Plan of Belém, established by law, of which the Manual is a part.
According to Noemi, the Manual offers a list of seventy tree and shrub species of distinct sizes and forms. “The choice of species must be made according to technical criteria and adapted to the different areas where the planting is to be carried out. Meticulous selection of seedlings, attention to the size of the hole, fertilization, management and protection of the plants must be priorities. There are several points to be improved in the urban afforestation of Belém, both in the continental area and in the insular area. Plant maintenance services must be permanent and not only during the rainy season, when rain falls are frequent. It is necessary to follow the recommendations described in the Manual, in addition to implementing all the points contained in the Law and in the Manual”, she emphasizes.
RECOVERY
The forestry engineer regrets that, over the years, there has been a discontinuation of the activities provided for in the legislation. “We hope that they will be reactivated with this new management of Semma, which has already held meetings with part of the team of technicians who participated in the drafting of the Law and the Manual and has already visited a farm to establish a partnership for the production of seedlings of species for urban afforestation. Embrapa remains available to continue contributing”, she assures.
Noemi also mentions that, all proposed programs need to be implemented. “The Manual recommends the production of seedlings according to technical standards; planting; management plan, with the completion of an inventory of the trees in public areas; and an Environmental Education program for urban trees, with the preparation of educational booklets in appropriate language, in order to increase the population’s awareness about the care of urban trees. There is a need to implement all of these legal and technical instruments,” highlights the engineer.
Guidebook lists ideal species for Amazonian cities
In January of this year, the Museu Paraense Emílio Goeldi (MPEG) launched the “Guia de Seleção de Árvores Ornamentais: Paisagismo Urbano para a Amazônia” [Guide for Selecting Ornamental Trees: Urban Landscaping for the Amazon], produced by researchers Rafael Salomão and Nelson Rosa. The manual offers an inventory of tree species to be used in urban landscaping in Amazonian cities, according to several considered features, such as biological, landscape, cultural and legal. The study evaluated 164 species, according to the selection matrix presented in the guide. Of these, 105 were considered to have great ornamental potential for urban use and occur naturally in the Amazon. Among them, are the pau pretinho (Cenostigma tocantinum), ingá costela (Inga capitata) and mari-mari pequeno (Senna multijuga). Others, originating from other regions of Brazil, are also recommended, such as oiti (Licania tomentosa) or barbatimão verdadero (Stryphnodendron adstringens).
For the selection process, aspects such as tree height, crown shape, flowering and foliage, cultural and legal value, use of the fruit, resistance to pests, maintenance and conservation costs, and longevity were considered. “Planting trees on public roads under electrical grids is even more restrictive in what concerns the attributes of the appropriate species, since pruning costs are high and this is often poorly conducted, causing great aesthetic damage to the landscape and to the comfort of the population”, recalls forestry engineer Rafael Salomão.
PLANNING
According to the researcher, most cities evidence the lack of adequate guidance for planning and managing tree planting. “Many projects were carried out without adequate technical criteria over time, with planting of species incompatible with the location, massive use of very few species, low quality of seedlings, lack of tutoring, inadequate pruning, among others. The results of this disjointed behavior are chaotic, both visually and in terms of the damage caused to streets, sewers, buildings, and electrical and telephone networks.
The desirable attributes of the species will vary according to the purpose of the project”, he points out. The forestry engineer illustrates the case of Belém. “The ten most abundant species in the city account for 91% of the total trees planted. Of these, only two are native to the Amazon: the balão chinês [Chinese balloon tree] (Calliandra surinamensis) and the açaí tree (Euterpe oleracea). The excessive number of trees, mostly, exotic to the local vegetation and the lack of variation (of species) are observed in hundreds of Brazilian cities, despite the fact that our flora has hundreds of species of great beauty and landscape quality”, he assesses.
THERMAL COMFORT
Salomão states that the main function of afforestation, in the Amazon region, is to provide thermal comfort to the population. Secondarily, aesthetic, cultural and landscape aspects are regarded.
“Amazonian cities are subject to very intense sunlight during practically every day of the year. As a result, the days are very hot, with high temperatures, in addition to high relative humidity. These factors cause great thermal discomfort, especially in large cities. Therefore, planting trees on public roads and squares is of fundamental importance to mitigate the effects of very high temperatures and relative humidity throughout the year”, he says.
Benjamim Lobato, also a delivery boy motorcycle, agrees. “The streets are very hot. Trees provide ventilation, fresh air, shade. Depending on the tree, even food. It is very important not to cut down trees in the city and to plant more, for us and for nature,” he concludes.
INSTITUTIONAL PARTNERSHIP
The production of Liberal Amazon is one of the initiatives of the Technical Cooperation Agreement between the Liberal Group and the Federal University of Pará. The articles involving research from UFPA are revised by professionals from the academy. The translation of the content is also provided by the agreement, through the research project ET-Multi: Translation Studies: multifaces and multisemiotics.
