albopictus lay desiccation-resistant eggs near the water surface in containers such as discarded tyres and cemetery vases. albopictus, in urban areas of southern Florida ( O’Meara et al. aegypti persists, sometimes despite invasion by A. albopictus invasion in northern Florida, A. Despite nearly total displacement from sites of A. O’Meara, FMEL, Vero Beach, FL, personal communication). aegypti populations disappeared from much of the southeastern United States, persisting only in parts of Texas, New Orleans, southern Florida ( Lounibos 2002, and Georgia (G.F. albopictus spread to almost all of the Southeast and portions of the Midwest United States ( Lounibos 2002, and at the same time, A. Aedes albopictus invaded the United States in Texas via shipments of tyres from Japan in the mid-1980s ( Hawley et al. Aedes aegypti invaded North America from Africa between the fifteenth and seventeenth centuries and its range covered much of the Southeast United States ( Tabachnick 1991). Although diverse tax a could thus exhibit fluctuation-dependent coexistence, we still have a poor understanding of the general importance of fluctuating conditions as drivers of community structure in nature.Ĭontainer dwelling Aedes mosquitoes are a desirable model system for field tests of the role of fluctuating conditions in communities. Variation in multiple environmental conditions, including temperature ( Holway, Suarez & Case 2002, Descamps-Julien & Gonzalez 2005, Jiang & Morin 2007), resource type ( Murrell & Juliano 2008, Juliano 2009), current velocity ( Taniguchi & Nakano 2000), and habitat drying ( Costanzo, Kesavaraju & Juliano 2005) can alter interspecific competitive interactions and contribute to coexistence. Fluctuating conditions might also have equalizing effects, which reduce fitness differences between competitors, and thus may reduce the strength of stabilizing effects necessary to maintain coexistence between competitors ( Chesson 2000), Adler, HilleRisLambers & Levine 2007). Periods in which the negative effects of intraspecific competition increase relative to the negative effects of interspecific competition can have stabilizing effects, which are required to maintain long-term coexistence ( Chesson 2000). Fluctuations in environmental conditions that negatively affect species densities can affect the relative strengths of intra- and interspecific competition if species respond differently to fluctuations ( Chesson & Huntley 1997, Chesson 2000). Recognition of the importance of fluctuating conditions as contributors to coexistence of competitors has grown since Hutchinson (1961) proposed it ( Chesson & Huntley 1997, Chesson 2000, Chase & Leibold 2003). Fluctuation-dependent mechanisms, on the other hand, only operate in environments in which conditions vary spatially or temporally. Fluctuation-independent mechanisms such as resource partitioning and predation operate equally in homogenous and heterogeneous environments. Mechanisms of coexistence are broadly categorized as being fluctuation-independent or fluctuation-dependent ( Chesson 2000).
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |