Do trees flower longer in the city? A comparison of flowering eucalyptus trees in streets, remnants and continuous forest and their association with nectarivorous birds

Abstract

Human-dominated environments are often subjected to increased nutrient and moisture regimes which have the potential to influence the flowering phenology of plants. Protracted flowering periods within urban landscapes may result in increased food resources, in the form of nectar, and this high resource availability may support a high density of nectarivorous birds within cities. In order to determine whether there was a difference in the productivity and flowering period associated with urbanisation, we compared the number of flowers produced and duration of flowering period for three species of native tree that were present in streetscapes, remnant vegetation and continuous forest. We also recorded the presence of nectarivorous parrots at flowering trees to determine if the presence of nectarivores was associated with flower productivity. All three species in streetscapes produced more flowers and flowered for longer than in remnants and continuous forest. The number of flowers per tree significantly predicted the presence of nectarivorous parrots in streetscapes. This study demonstrates that the flowering phenology of plants within streetscapes can differ from continuous forest, with remnants appearing to be intermediate. This increased flower productivity within urban landscapes may be partially responsible for the high abundance of nectarivorous parrots within some cities.

Butterfly richness and abundance along a gradient of imperviousness and the importance of matrix quality

“…For instance, the most abundant butterfly species in our surveys, common grass blues (GB), readily use the introduced white clover ( Trifolium repens ), one of the three most abundant species in our floral abundance surveys, as a larval host plant. In terms of adult food resources, the primarily native flowering plants in remnants and natural areas tend to have a short flowering periods in contrast to the much longer flowering periods of the mostly ornamental plants found in suburban and urban areas (Neil and Wu 2006, Leong and Roderick 2015, Davis et al 2016). This can perhaps limit the importance of remnant habitats because some of the resources they provide occur elsewhere within the urban environment.…”

Urbanization, environmental stabilization and temporal persistence of bird species: a view from Latin America

“…Gorton, Moeller & Tiffin (2018) found that the plant Ambrosia artemissifolia flowered earlier in urban than in rural habitats of Minneapolis (USA), and attributed this asynchronous flowering to genetic differences between populations. On the other hand, Davis, Major & Taylor (2016) found that native trees in Sydney (Australia) flowered longer in streets than in remnant and continuous forests, providing more food resources to nectarivorous birds. Nectar and fruits may be available during seasons when they would be naturally absent or scarce due to the planting of ornamental trees (Williams & Karl, 1996; Corlett, 2005; Leston & Rodewald, 2006; Williams et al, 2006; Montaldo, 1984; Leveau, 2008; Leveau & Leveau, 2011; Davis, Major & Taylor, 2015; Gray & Van Heezik, 2016) (Fig.…”

Peer Review #1 of "Urbanization, environmental stabilization and temporal persistence of bird species: a view from Latin America (v0.1)"

“…On the other hand, Davis et al (2016) found that native trees in Sydney (Australia) flowered longer in streets than in remnant and continuous forests, providing more food resources to nectarivorous birds. Nectar and fruits may be available during seasons when they would be naturally absent or scarce due to the planting of ornamental trees (Williams and Karl, 1996;Corlett, 2005;Leston and Rodewald, 2006;Williams et al, 2006;Montaldo, 1984;Leveau, 2008;Leveau and Leveau, 2011;Davis et al, 2015;Gray and van Heezik, 2016) (Figure 1).…”