After the worms it would be moles and voles. Then mice. Then snow rabbits, and ermine, and marmots; perhaps then some of the snow cats wandering the moors would drop by. Foxes. The basin was high, but the pressure they were hoping for at this altitude was four hundred millibars, with forty percent of that oxygen; they were already most of the way there. Conditions were somewhat as in the Himalayas. Presumably all of Earth’s high-altitude flora and fauna would be viable here, and all the new engineered variants; and with so many ecopoets stewarding small patches of the upland, the problem would be mostly a matter of prepping the ground, introducing the basic ecosystem desired, and then supporting it, and watching what came in on the wind, or walked in, or flew. These arrivals could be problematic of course, and there was a lot of talk on the wrist about invasion biology, and integrated microcline management; figuring out one’s locality’s connections to the larger region was a big part of the ongoing work of ecopoesis.

Nirgal got even more interested in this matter of dispersal the next spring, in first November when the snows melted, and poking out of the late slush on the flat terraces of the northern side of the basin were sprigs of snow alumroot. He hadn’t planted them, he had never heard of them, indeed he wasn’t even sure of his identification, until his neighbor Yoshi dropped by one week and confirmed it: Heuchera nivalis. Blown in on the wind, Yoshi said. There was a lot of it in Escalante Crater to the north. Not much of it in between; but that was jump dispersal for you.

Jump dispersal, spread dispersal, stream dispersal: all three were common on Mars. Mosses and bacteria were spread dispersing; hydrophilic plants were stream-dispersing along the sides of glaciers, and the new coastlines; and lichen and any number of other plants were jump-dispersing on the strong winds. Human dispersion showed all three patterns, Yoshi remarked as they wandered over the basin discussing the concept— spreading through Europe and Asia and Africa, streaming down the Americas and along the Australian coasts, jumping out to the Pacific Islands (or to Mars). It was common to see all three methods used by highly adaptable species. And the Tyrrhena massif was up in the wind, catching the westerlies and also the summer trade winds, so that both sides of the massif got precipitation; nowhere more than twenty centimeters a year, which would have made it desert on Earth, but in the southern hemisphere of Mars, that was a precipitation island. In that way too a dispersion catchment, and so very invasible.