Birds, landscape connectivity and environmental planning in urban landscapes (original) (raw)
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The composition of the urban vegetation that comprises the green infrastructure of a highly urbanized Neotropical city was mapped and described in order to assess how it can be used to preserve and maintain urban biodiversity. Supervised classification was used, followed by Map Algebra methodology, to identify the elements that comprise the green infrastructure of the southern region of Belo Horizonte (Minas Gerais, Brazil). Species composition of the street trees community was also assessed. Almost half of the study area is occupied by 12 types of woody and herbaceous vegetation, composed mostly by urban parks and gardens. Forty-one percent of the almost 90,000 street trees is composed by 10 species from which only four are native. These results show that the green infrastructure of this urban landscape is comprised by a large amount of different types of green elements, and has a great potential for biodiversity conservation. However, management strategies are needed such as better planning of the urban afforestation process, increasing street tree species richness. This study is the first step towards a better understanding of how such urban landscape influences local biodiversity.
Revista da Sociedade Brasileira de Arborização Urbana
We mapped and described the composition of the urban vegetation that comprises the green infrastructure of a highly urbanized Neotropical city, and discussed how it can be used to preserve and maintain urban biodiversity. Almost half of our study area is occupied by 12 types of arboreal and herbaceous vegetation, composed mostly of urban parks, gardens and street trees. Forty-one percent of the almost 90,000 street trees are composed of 10 species with only 4 native species. These results show that this urban landscape is highly heterogeneous and has a great potential for biodiversity conservation. However, management strategies are needed, such as better planning of the urban forestry. This study is the first step towards a better understanding of how this landscape influences local biodiversity, and can be used as a management tool to increase urban resilience and functionality.
Relation between green spaces and bird community structure in an urban area in Southeast Brazil
Urban Ecosystems, 2012
Increased urbanization typically leads to an increase in abundance of a few species and a reduction in bird species richness. Understanding the structure of biotic communities in urban areas will allow us to propose management techniques and to decrease conflicts between wild species and human beings. The objective of this study was to describe the structure of the bird community in an urban ecosystem. The study was carried out in the city of Taubaté in southeastern Brazil. Point-counts were established in areas with different levels of tree density ranging from urban green spaces to predominantly built-up areas. We looked for a correlation between the richness/abundance of birds and the size of the area surveyed, the number of houses, the number of tree species and the number of individual trees. The results of multiple regression showed that bird richness had a direct relationship with vegetation complexity. The abundance and diversity of tree species were better predictors of bird species than the number of houses and size of the area surveyed. We discuss implications of this study for conservation and management of bird diversity in urban areas, such as the need to increase green areas containing a large diversity of native plant species.
The ecology and tree species of urban green areas within the municipality of Campestre, Minas Gerais
Urban green areas produce benefits such as reduced air pollution, climate mitigation, reduced wind action, less noise pollution, shelter for fauna, and increased water uptake from the soil as well as increased water infiltration to the soil. This work carried out a floristic survey related to its diverse and characterized habit and dispersion, and also related to the origin of the species existing in four public squares within the municipality of Campestre, Minas Gerais. Thus, the floristic and ecological aspects of trees and shrubs were surveyed in four urban green areas of the municipality. All arboreal and shrubby individuals were marked and identified. Each identified species was classified according to habit, dispersion, and origin. In total, 313 tree individuals, shrubs, and palm trees were registered and distributed among 73 species, (62 genera and 30 botanical families). When considering all squares, Shannon’s diversity was 3.72, and Pielou’s evenness coefficient was 0.87. Lower values of diversity and evenness were observed for each public square. There was greater richness and number of individuals of native species compared to exotic ones. The yellow ipe (Handroanthus serratifolius) was the only species present in all studied squares. Sassafras (Ocotea odorifera) and pau-brasil (Paubrasilia echinata) are endangered species and underrepresented. The most represented forms of dispersion were zoochory and anemochory.
Urban Ecosystems, 2010
Shaped by European influences, the Brazilian urban landscape was marked by the predominant use of exotic species in planted areas. In the 19th century along the city streets of Rio de Janeiro, trees were planted at a standard distance from each other. With time, native species began to be used in the urban landscape. Our purpose was to evaluate the utilization of exotic plant species in the urban landscape of Rio de Janeiro, evaluate the city’s arboreal deficit, and relate its neighborhood arboreal density to its economic index. Arboreal deficit represents the negative difference between the total number of expected trees and the observed number in the streets based in the standard distance used in the past. Twenty native and 40 exotic species were found in the 1701 streets sampled. A high percent of streets did not have any planted trees and the number of trees was greater in wealthier neighborhoods. The strong prevalence of exotic species is indicative of the negative impact of human activity on the biota. Since the municipality of Rio de Janeiro harbors forested areas, the risk for dissemination of exotic species is high.
Composition and Functional Diversity of the Urban Flora of Alfenas-MG, Brazil
Floresta e Ambiente, 2019
Urban tree cover has important environmental and social functions and can act as ecological refuges. The objective of the present study was to investigate the taxonomic and functional diversities of urban plant communities in Alfenas, Minas Gerais State, Brazil. We sampled all trees DBH ≥ 3 cm in eight different urban green areas, recording 1,138 individuals and 119 species; two species were dominant: Poincianella pluviosa (Fabaceae) and Syagrus romanzoffiana (Arecaceae). The high species richness encountered reflected, in part, the presence of exotic species, which corresponded to 40% of the species and 25% of the total abundance. The functional diversity index (HF') was considered low, with the predominant functional traits among the species being small size, entomophily, zoochory, evergreen leaves, and dry fruits. We recommend that future urban afforestation projects incorporate strategies that increase the use of regional species as well as the functional diversity/complexity of those environments.
Characteristics of novel urban vegetation in two Portuguese urban regions
Landscape Research, 2022
Urban novel ecosystems were sampled across vacant sites in two Portuguese urban regions. The flora were studied with a focus on species' origin, life form, ecological, chorological and naturalisation types. A multivariate constrained ordination technique was used to identify relationships between plant composition and environmental factors. The vegetation of the two urban regions shows differences, highlighting biome influence, as well as due to climatic variables and (to a lesser degree) soil characteristics and lithology. Although native species are clearly dominant, the frequency of non-native species is high and most are potentially or effectively invasive. In the ecological spectrum, the dominance of opportunistic ruderal species suggests a risk of biotic homogenisation in these ecosystems, which is also noticeable in the analysis of life form, but less in chorological and nativeness spectra. Portuguese novel urban ecosystems are, therefore, simultaneously an opportunity, since spontaneous vegetation management is more cost effective and can bring wilderness to cities; and a hazard, because invasive species must be controlled to support biodiversity conservation efforts.
Brazilian landscape styles and tree biodiversity in public garden squares
FLORESTA
The main features of the Brazilian contemporary landscape style are the recovery of degraded areas and the use of indigenous species. This study aimed at analyzing the vegetation of the Curitiba-PR public garden squares to verify if the areas created during the contemporary period (from 1990 on) have a greater diversity of tree species than other squares and, therefore, are more significant for biodiversity conservation. For this, 32 of the city's 454 squares were sampled as determined by statistical calculation, then classified by creation year and landscape style. Trees species, families, and individuals were identified and classified as to their origin; and the variables richness; average species; number of individuals; density of individuals; and the Shannon, Pielou, and Odum indexes were analyzed. The 15 contemporary style squares presented 399 individuals of 54 species and 27 families, with 43.61% of the individuals and 50.00% of the species of exotic origin; individuals a...
Semiarid Mediterranean areas patchily forested with Pinus halepensis Mill. are often affected by urbanisation plans, which influence the conservation of biodiversity in the remaining fragments. We assessed forest biodiversity in eleven Pinus halepensis patches of the municipality of Murcia (SE Spain), on the basis of the abundance, richness and conservation value of birds and woody flora. Under the hypothesis that biodiversity is conditioned by pine density, modulated by other patch features (age, physical substrate, surrounding land uses), mixed regression models were used to relate biodiversity indicators with environmental gradients, detected through principal component analyses (PCAs) performed on three sets of variables: landscape (L); habitat structure (H); and, stand development (S). PCA-L related patch size and connectivity to the abundance of typical woodland birds and to floral and bird species richness. PCA-H related shrub cover associated with Sylvia melanocephala Gmelin., to rock and dry grassland cover, a feature of moderately disturbed areas preferred by Lanius senator L. PCA-S associated taller trees and better physical conditions with canopy dwelling and soil probing bird species, respectively. The bird or plant conservation value of patches did not generally match their protection status, which was confirmed by the analysis of a larger sample of 36 natural patches. A negative relationship between floristic value and pine density suggests that reducing the density of reforestations can lead to more diverse and self-sustaining wooded formations. In contrast, conservation value for birds did not decrease with reforestation, stressing the need to use ornithological and floristic indexes as complementary assessment tools. The results seem useful for building a municipal network of reserves connecting higher status protected areas.