For the conservation of species, hostile territory might sometimes have its advantages. That's according to a study of pollen flow among trees found only in remnant patches of native Chilean forest. The data show that the pollinators those rare trees rely on can be waylaid by the abundance of resources found in agricultural lands. As a result, trees growing in native forest patches are more likely to mate successfully when separated by resource-poor pine plantations than by those more attractive farmlands.
The finding reported in the July 21st Current Biology, a Cell Press publication, contradicts current wisdom that habitats hostile to an organism act as barriers to movement and attractive habitats act as corridors. The research team led by David Boshier of the University of Oxford explain the unexpected findings by what they refer to as the "Circe Principle."
"Many existing models for pollinators in fragmented landscapes assume that generalist pollinators are more likely to travel through attractive land-uses, especially those most similar to native habitat," said co-author Tonya Lander. "The Circe Principle suggests the reverse; pollinators presented with a wealth of resources, whether inside or outside traditionally defined 'habitat' are likely to move through it slowly or not leave it at all - much as Odysseus was waylaid on Circe's island, preventing his return to the waiting Penelope."
Pollinators presented with hostile or resource-poor lands may not enter at all. But when they do, they are likely to move through as quickly as possible. Earlier models had missed this by focusing on the problem only from the perspective of the trees, not from that of the insects that pollinate them.
"The insects are generalists," Boshier said. "They visit a wide variety of plant species rather than having an obligate relationship with a single species, so they have no specific investment in finding the next tree of the same spe
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