Índices espaciais e de diversidade florística das zonas central e residencial central de Imperatriz - MA

Abstract

Considering the importance of trees for providing the beautification of cities, the amelioration of the local temperature and other factors, it is necessary to know the species that make up the urban forestry, which can be assessed through the inventory. After the floristic survey it is possible to measure the quality of the afforestation through indices of wealth and / or spatial indexes of the trees on public roads. Based on this, this study aimed to study the urban forestation in two central regions of the city Imperatriz - MA, evaluating wealth, dominance, equity and spatial indices. To this was done a total inventory of individual trees, which is included tree height ≥ 1.5 m, diameter at breast height - CAP rays and height of the canopy height of 1st data fork and also the urban network (width and length of sidewalk and pathways, distance from the tree to the curb, dimensions of the free growing area, spinning height and distance between trees). All data were entered in Microsoft Office Excel spreadsheet program where wealth indices were calculated: Shannon-Weaver (H '), Odum, Menhinick (Dmn) and Jentsch (QM), diversity indices; Simpson (D) McIntosh (dominance); Evenness (J) and Bulla (E) (fairness) and spatial indexes: ICA, IPO deficit, ICV, IDA IAQC, PCV IAVT, IAVPB, IAVPV, AVB, IPT IPE Sad, and Npot dfut. In the study yielded a total of 228 scheduled blocks, 145 blocks and belonging to the central zone (ZC) and 83 Central Residential (ZRC). 2321 individuals were scheduled distributed in 69 species and 27 botanical families. It was also found that the total area found 24 species of native origin and 45 exotic. Through the floristic characterization, it was observed that Licania tomentosa (Benth.) Fritsch and Azadirachta indica A. Juss s will be the most common species which represents 63.77% of the subjects. The richness indices show low diversity of species (H +, Dmn and QM), except Odum index. The dominance indexes show low diversity, showing that there is a high dominance of few species. And the equity indices show a low uniformity of the number of trees for the number of species. Overall, the ZRC proved to be less diverse, with greater dominance and less equity. As for spatial indexes s results demonstrate that the occupation of the cups with respect to area walkways are below the recommended both pa ra total area (19.81%) and for ZC (25.11%) and ZRC (16.93 %), representing a total deficit of 7570 trees, representing 76.5% percentage deployment individuals so that there was full occupancy. Regarding the number of inhabitants, the arborization of Imperatriz roads and squares is also inadequate, as demonstrated by the ICV (1.03 m² / inhabitant), IAVT and IAVPV (0.70 m² / inhabitant). Therefore, it is possible to notice that the study area in Imperatriz has low diversity, with few individuals in relation to the number of species, it also shows a disproportion between the number of trees per species. On the other hand, the study area has the potential to be planted with new trees provided there is adequate planning through a master plan for urban afforestation.