Reduced reproductive success of the endangered tree brazilwood (Paubrasilia echinata, Leguminosae) in urban ecosystem compared to Atlantic forest remnant: lessons for tropical urban ecology

《Reduced reproductive success of the endangered tree brazilwood (Paubrasilia echinata, Leguminosae) in urban ecosystem compared to Atlantic forest remnant: lessons for tropical urban ecology》

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来源: URBAN FORESTRY & URBAN GREENING,Vol.41,P.303-312

语言: 英文

关键字: Bee; Floral traits; Fruit set; Pollination; Reproductive phenology; Urbanization; HABITAT FRAGMENTATION; FLOWERING PHENOLOGY; PLANT PHENOLOGY; AIR-POLLUTION; DRY FORESTS; SEED SET; POLLINATION; URBANIZATION; IMPACTS; SOIL

作者单位: [Oliveira, Willams; Souza e Silva, Jessica Luiza; Pontes de Oliveira, Marcela Tomaz; Cruz-Neto, Oswaldo; Pinheiro da Silva, Luanda Augusta; Lopes, Ariadna Valentina] Univ Fed Pernambuco UFPE, CB, Dept Bot, BR-50372970 Recife, PE, Brazil. [Borges, Lais Angelica] Univ Fed Paraiba UFPB, Ctr Ciencias Agr, Dept Ciencias Biol, BR-58397000 Areia, Paraiba, Brazil. [Sobrinho, Mellissa Sousa] Univ Fed Amapa UNIFAP, Campus Mazagao, BR-68940000 Mazagao, AP, Brazil. Lopes, AV (reprint author), Univ Fed Pernambuco UFPE, CB, Dept Bot, BR-50372970 Recife, PE, Brazil. E-Mail: avflopes@ufpe.br

摘要: Human activities have drastically altered natural ecosystems, mostly by converting forests into agricultural and urban areas. Brazilwood (Paubrasilia echinata) is an endangered tree endemic to the Brazilian Atlantic forest originally occurring along the whole coast. The species is largely planted in urban areas due to its ornamental potential. In this paper, we compared the phenology, floral traits and the reproductive success of P. echinata between urban and natural ecosystems. We have hypothesized that individuals in urban ecosystem will have: i) reproductive phenophases lasting longer than in natural, ii) lower number of pollen grains and ovules per flower, iii) lower richness and frequency of flower visitors, and iv) lower natural fruit and seed set. The study was carried out in urban green spaces of the city of Recife and in an Atlantic forest remnant, both in Pernambuco State, northeastern Brazil. The species flowered and fruited practically all year round in the urban ecosystem, contrasting with the annual pattern of flowering and fruiting observed in the natural area. We documented that brazilwood trees in urban areas had smaller inflorescences, fewer flowers/inflorescences, larger flowers, less pollen/flower, lower richness of floral visitors and lower fruit and seed set when compared to natural ecosystem. Also, when considering the most frequent effective pollinator, the invasive bee Apis mellifera predominated in urban, whereas the autochthonous pollinator Centris aenea prevailed in natural. Moreover, C. aenea acted as occasional pollinator in urban area because the flowers of P. echinata are larger in this ecosystem. Independent of the underlying mechanism, the brazilwood had an impoverished richness of native pollinators and a significant reduction in the reproductive success in urban ecosystem, indicating an impairment in the pollination process. The viability of planting trees in tropical urban areas as an ex-situ conservation alternative for species obligatory dependent on cross-pollination, such as P. echinata, may be compromised.