Urban arborization in public pathways of four cities in east Mato Grosso do Sul ( MS ) Brazil

The study of urban arborization can generate great contributions to urban planning, mainly for new and fast-growing cities. Aiming quantifying and qualifying urban arborization in Cassilândia, Chapadão do Sul, Costa Rica and Paranaíba, in Mato Grosso do Sul State, Brazil, we performed a survey of tree species present in 30 blocks of each city. All trees were evaluated regarding tree size, planting site, pruning and physical conservation status. The species were classified native or exotic. There were 3180 individuals and 89 species, with the highest abundance of Brazilian native trees (69%), although the richness of exotic species was higher (78%). Chapadão do Sul had the largest individuals number and Paranaíba, the smallest. The diversity index was low for all cities, especially because of the large number of oitizeiros (Licania tomentosa) registered, totaling more than half of the trees surveyed. The widespread use of only one species, as found for the oitizeiro in this study, is not recommended because it reduces diversity and increases the chances of diseases and pests in trees in the urban environment. However, it was observed a high incidence of species used in urban arborization, and tree maintenance aspects, such as pruning, were satisfactory in the four studied cities.


INTRODUCTION
Trees are characteristic features of the urban landscape and have a decisive influence on the welfare of urban populations (GONÇALVES and ROCHA, 2009).Historically, they have been closely related to the architecture of cities, and although Brazilian historical material on arborization is scarce, it is known that cultural differences in Brazil have provided different urban models.Planning for arborization is fundamental for urban development and requires, firstly, that the existing scenario be known through a quali-quantitative inventory, as well as to know the biology of plants that can potentially be used (COLETTO et al., 2008).
The fragility and complexity of urban planning require actions that maximize the functions of arborization and reduce costs both for the population and the public administration.Technical and scientific concerns have increased over the last two decades, motivating some specific works, which have produced new knowledge on the behavior of species in urban areas (KURIHARA et al., 2005;SILVA FILHO et al., 2005).
Survey and diagnosis of urban arborization can generate great contributions to urban planning.Many techniques have been disseminated for the correct implantation, monitoring and maintenance of arborization (LIMA NETO and BIONDI, 2012).However, it is still common that few tree species represent the majority of individuals in urban arborization, even though it is not recommended (RODOLFO JÚNIOR et al., 2008;GONÇALVES and ROCHA, 2009).This trend was observed in some cities of Mato Grosso do Sul, Brazil, such as in Chapadão do Sul (PELEGRIM et al., 2012) and Campo Grande, the state capital (PESTANA et al., 2011).
In this sense, the objective of this study was to characterize qualitative and quantitatively the arborization of public roads in four cities in the eastern state of Mato Grosso do Sul State: Cassilândia, Chapadão do Sul, Costa Rica and Paranaíba.

MATERIAL AND METHODS
The study was carried out in four municipalities located in the eastern mesoregion of Mato Grosso do Sul State, Brazil: Cassilândia, Chapadão do Sul, Costa Rica and Paranaíba, with about 20,966, 19,648, 19,695 and 40,192 inhabitants, respectively (INSTITUTO BRASILEIRO DE GEOGRAFIA E ESTATÍSTICA, 2012).
The data of urban arborization were collected in 2012 and adapted from the methodology used by Barros et al. (2010).Thus, the sample unit adopted was the city block, standardizing for the study, that was constituted of four sides, predominantly found in all four municipalities.For each city, 30 blocks, independently of the neighborhood, were randomly selected, totaling 120 sampled blocks, where were recorded all woody plants and palm trees present on the sidewalks.Specific literature was used for species identification, in addition to comparison with Herbarium vouchers.The species were classified into families according to the Angiosperm Phylogeny Group (APG IV, 2016).The names and authorship of the species were checked on the Tropicos® website.
To evaluate differences in plant diversity among the four cities, we used the Shannon diversity index (H›), assessing significance by the Hutcheson t test at 5% significance.Comparisons were made in pairs between the four cities, in a total of six combinations.In order to compare the observed diversity with the maximum expected, the Pielou evenness index (J') was used, which refers to the distribution pattern of the individuals among the species, with a value equal to 1, referring to the maximum uniformity.
Based on the characteristics of each species, these were categorized as small trees, up to 6m high, and medium to large, with a height of more than 6m.It is worth remembering that in this first category (< 6 m), some species were typically registered with shrubby lifeform, but during the survey they were being driven as saplings trees.The planting site was also registered, whether in private places such as residences, commerce or industry, and even if planted in public places such as schools, churches or hospitals.Regarding to the origin, the trees were classified as exotic or native to Brazil.The species were also classified as fruit plants if they were suitable for human use.
Trees were visually assessed for physical damage with respect to the general state of the plants by assigning a scale of scores, based on Backes et al. ( 2011), with modifications: 1. sound tree, without signs of physical damage (good); 2. intermediate conditions of vigor and health (satisfactory), and 3. advanced tree decline with severe physical damage (bad).They were also classified for pruning, according to the following description (sensu VOLPE-FILIK et al., 2007 andBACKES et al., 2011): 1. none: no traces of any type of pruning; 2. correct: regular pruning or ornamental pruning, adorned with various configurations.Reduction of size for suitability to urban equipment, such as electricity and telephone network; 3. incorrect: excessive branching, altering the typical structure of the tree, or trees with a Vor L-shaped canopy; 4. radical: trees with abrupt cuts or completely cut, with total removal of the crown.

RESULTS AND DISCUSSION
The survey recorded 3,180 trees, belonging to 89 species and 40 botany families.The four cities studied (Cassilândia, Chapadão do Sul, Costa Rica and Paranaíba) showed respectively 838; 1,130; 657 and 555 trees (Table 1).This is a satisfactory density in relation to the size of the sample, when it is denoted the arborization in the urban perimeter of cities.For Rocha et al. (2004) the high species number found in surveys indicates an interference of the local population, who carries out continuous and random plantings.
V. 24, N o .2, 2018 p. 174-181 Although, in the four cities studied, a high number of individuals were recorded, the diversity index (H '= 2.08) was low.Significantly higher diversity indexes were observed in CO and CH, while CA showed the lowest diversity (Table 1).Other studies with urban arborization in São Paulo State found higher diversity indexes, varying from 2.6 to 3.9 (BORTOLETO et al., 2007;ROSSATTO et al., 2008).However, in Brazilian cities, the low variety of planted species still prevails (PELEGRIM et al., 2012).The low diversity found in the study can be explained by the high number of oitizeiros (Licania tomentosa) recorded in all cities.There were 1,876 oitizeiros (59% of total recorded), representing 85% in CA, 36% in CH, 57% in CO and 66% in PA (  (BRANDÃO et al., 2011).Therefore, the use of the species is much higher than that proposed by Santamour Júnior ( 2002), who recommends no more than 10% of the same species, 20% of some genus and 30% of a botanical family.
Although 22 fruit species were found in the survey, only 3.6% comprised the total sampled individuals (Table 1).However, this result was superior to that found by Rossatto et al. (2008) in Assis, São Paulo State, Brazil, which found 0.5% of the total of individuals distributed in eight fruit species.According to Rocha et al. (2004) the presence and the variety of fruit trees planted on the sidewalks may indicate the participation of the local population in the arborization, as a desire to create an urban garden.Fruit species provide food for humans, generate some benefits for the local community, such as the possibility of harvesting fruits on the sidewalks, as well as enhancing the attraction of small animals, especially birds (CARVALHO et al., 2010).Although the use of fruit trees in urban arborization is not advisable, as some species may foul public roads and serve as food for vectors of diseases, such as flies, rats and cockroaches.
Of the total trees sampled in the study, 22% are composed of exotic trees, while 69% and only 9% are distributed in native plants to Brazil and Cerrado, respectively.However, of the 89 species recorded, 78% are exotic, 16% are native to Brazil and only 6% are native to Cerrado (Table 3).Our findings are similar to other studies, where usually there is a greater proportion of exotic species than native ones (BORTOLETO et al., 2007;MIRANDA and CARVALHO, 2009;SILVA et al., 2008).The widespread use of alien species in urban arborization is undesirable, whereas may have impacts on biodiversity and regional decharacterization (STUMPF et al., 2015).On the other hand, the greater abundance of native species in the present study is notorious and important, since it favors the preservation of endangered native species and maintains the cultural customs of the region, such as medicinal and culinary use.In addition to these aspects, the use of native species can facilitate the establishment of seedlings and reduce maintenance costs of city arborization, considering that these are better adapted to the environmental conditions of the region's origin.They can also, in general, play a fundamental role in the supply of food for the native animals (SANTOS et al., 2011), even in the urban perimeter of the cities.Even though present with lower density and plant richness in the current study, the use of native Cerrado species in urban arborization is recommended, although information on its use in cities is still scarce.Tree seedlings in southwest of Goiás, a region bordering the cities studied in Mato Grosso do Sul, have shown that ingás (Inga spp), ipês (Tabebuia spp and Handroanthus spp) and canafístula (Peltophorum dubium) increase satisfactorily.Therefore, among several other tree native species, they are indicated for use.Among of the 3,180 registered trees, 80% were planted in front of the residences, 14% in other public places, such as churches, schools and day care centers.Only 6% of the trees were registered in front of commercial establishments, which may be related to the greater visibility of the forefront and the lack of planning and control of the municipality.According to Ferreira et al. (2009) the small tree number in front of commercial establishments shows the lack of planning in these places and their preference in highlighting the forefront.In addition, in general there is no retreat of the built-up areas, which also prevents the implantation of trees in these places.
Of the total trees registered in the study, 44% were free and 56% under electric wiring, of which 10% showed conflicts.A similar result was found by Miranda and Carvalho (2009), where 10% of the trees presented conflicts with wiring in Ponta Grossa, Paraná State.In Pombal, Paraná State, Brasil there was interference of up to 50% of trees in the electrical network in several neighborhoods studied (RODOLFO JÚNIOR et al., 2008).In general, these conflicts are related to the planting of large size species under the wiring, without planning and pruning of maintenance.According to Gonçalves and Rocha (2009) and Silva et al. (2008), the contact of the trees in the electricity wiring generally worries all the energy distribution companies, due to the incompatibility between the arborization and elements of the urban road.Usually this is due to the lack of planning, and often the trees are pruned without the technical support.According to PIRES et al. (2007), the most efficient procedure would be the planting of small size species under the electric and telephone network.However, many specialists have recommended that electric and telephone networks should be designed so as not to conflict with larger trees.
Regarding to the trees physical condition in the four cities studied, 81% (2,558 trees) showed good conditions, 17% (531 trees) satisfactory condition and 2% (61 trees) bad maintenance conditions (Figure 1-A).Similar results were recorded by Batistel et al. (2009) when comparing two neighborhoods of Quirinópolis, Goías State, Brazil, which found that the majority (between 73 and 89%) of the trees planted were in good conditions.Regarding to pruning, 75.4% of the trees sampled were pruned correctly, 10% incorrect, 12% non-existent and 2.6% drastic (Figure 1-B).Volpe-Filik et al. (2007) and Miranda and Carvalho (2009)  Paraná State, Brazil, respectively.A different result was found by and Rocha (2009) in Vila Maria, São Paulo State, Brazil, with 58.5% of the individuals sampled with drastic pruning.We can note that the pruning quality and trees maintenance are directly related, therefore, with similar results recorded.This reinforces the importance of good pruning, and even more important, of knowing which tree species to plant in a given site.

CONCLUSIONS
In the four studied cities of the east of Mato Grosso do Sul State, Brazil, 89 species were sampled.Although with a high richness, in general, were registered low species diversity, mainly due to the homogenization of the urban arborization, characterized by the predominance in the use of oitizeiros.However, in general, there is a high incidence of plants used in the arborization of the studied cities, and the raised trees presented pruning and satisfactory physical conservation aspects.

Figure 1 .
Figure 1.Physical aspects of damage (A) and pruning features of trees (B) in four cities in Mato Grosso do Sul, Mato Grosso do Sul State: Cassilândia (CA), Chapadão do Sul (CH), Costa Rica (CO) and Paranaíba (PA).

Table 1 .
Values of density, richness and diversity of species recorded in four cities in Mato Grosso do Sul (MS), Brazil.
Different letters indicate significant differences in diversity, by the Hutcheson t test.

Table 2 .
Species list, in decreasing order, of total abundance in the urban arborization of four cities in Mato Grosso do Sul, Mato Grosso do Sul State, Brazil: Cassilândia (CA), Chapadão do Sul (CH), Costa Rica (CO) and Paranaíba (PA).

Table 3 .
Richness (S) and density (D) in relation to the species origin (exotic or native of used in urban arborization in four cities in Mato Grosso do Sul (MS), Brazil.
recorded the highest number of trees with drastic pruning in Piracicaba, São Paulo State and Ponta Grossa, V. 24, N o .2, 2018 p. 174-181