Alan Weisman’s book, The World Without Us, in part inspired my blog. In his book he imagines a world where humans suddenly become extinct, and he speculates about the resulting ecological changes and how anthropogenic structures would decay. I am particularly interested in landscapes devoid of human influence. I chose to devote my blog to the paleoecology of southeastern North America as it was before people lived here, rather than after people become extinct. But for this blog entry, I am going to speculate about what changes would occur to my lot and my immediate neighborhood, if a plague suddenly wiped out 100% of worldwide humanity.
Without anyone around to maintain it, my house would become covered in grape vines, Virginia creeper, and pine straw in 3 years. After 100 years the only thing left standing would be the chimney. Sand, held down by pioneer plants, would cover the road completely.
During the growing season, I have to constantly cut back the Virginia creeper that otherwise would completely cover my house.
My peach trees would probably die in less than 20 years, but my blueberry bushes, persimmon and mulberry trees, and chives would likely still be alive after 20 years.
My patch of sunchokes would last decades…until trees shaded them too much.
My House 20 Years After the Extinction of Homo sapiens
I rake the pine straw off my roof twice a year and cut back Virginia creeper and grape vines twice a month during the growing season. Without me all 3 completely covered my house in 3 years. This hastened wood rot. A sagging area of my roof caved in and several generations of squirrels have lived in the attic. The house is still standing, though the roof leaks in numerous places and the inside smells like mildew. An oak tree in the front yard is now quite large and some of its branches cover my daughter’s Toyota Corolla. The tires on both Toyotas are flat, and the metal bodies are rusting. A hailstorm cracked windows, and some are shattered. Mosquitoes breed in puddles on the floorboard of 1 of them.
The peach trees in my scrub-covered backyard have died, but the mulberry, a native tree, is thriving and forms a closed canopy on the side of the yard with a black cherry and oak. Both native fruit trees provide plenty of summer food for songbirds. Much of the backyard is near impassable thicket and home to a happy family of rabbits. The lot across the street from mine is also a thicket of pine and oak saplings and persimmon, most of it covered in vines. Before people became extinct, a street sweeper kept sand from covering the road in front of my house. But now most of the road is covered in sand, leaves, pine straw, and other organic debris; and pioneering grasses and flowers are taking root in many places. The road is the only passable track in the vicinity and serves as an animal trail. Scat of all kinds is visible.
Human hunters and automobiles caused a 30% annual mortality rate in the deer population. But after humans became extinct the deer population skyrocketed, and it is still high 20 years later. Herds of 200 occasionally form, and they browse down much of the vegetation but here in the south with a long growing season, they never starve. Instead, predator populations increased and partially keep the deer population in check. Both coyotes and bobcats take a toll, especially on spring fawns. Wild hogs have expanded out of nearby Phinizy Swamp and are regular travelers along the road. They eat pine sapling roots and acorns but don’t seem to be having a big impact on the dense young forests popping up everywhere. Rabbits like the yards that have become covered in scrub habitat. Feral cats hunt them. They are still abundant but suffer shorter lifespans without people feeding them. Packs of feral dogs are uncommon because coyotes outcompete them. Cougars and bears are increasing elsewhere but have not yet colonized the vicinity.
Without humans cats would be just as abundant as they are now, but they would have shorter lifespans.
My Lot 100 Years After the Extinction of Homo sapiens
The chimney is the only structure still standing from my old house. Most of the houses on this street look like collapsed ruins. Some power line poles have rotted and tipped over, and during several ice storms trees smashed through power lines. About half the poles still stand but the wire is all on the ground covered in dense vegetation. The ground around my former home is littered with bricks, most covered with dirt, grass, leaves, and pine straw. A sapling is growing through a crack in the cement slab that my house formerly rested upon. The rusty washing machine and dryer are covered in brambles. There is a squirrel’s nest on top of the refrigerator. A rotting pine log and all sorts of organic crud camouflage what used to be a queen-sized bed. The fabric rotted away, but the springs and metal parts can still be seen. An oak is growing through 1 of the rusted hulks that used to be a car. My backyard is a thick forest. However, the lot across the street is more of an open woodland. Perhaps a fire burned through that side of the road. The road is not recognizable–scrub vegetation broke through cracks in the pavement which is now only visible in a few eroded places. However, an animal trail still winds around in the general direction of where the road used to be.
Deer and wild hog are still abundant and are preyed upon by coyotes and bobcats here, but a cougar includes my lot as part of his territory. Bears occasionally pass through too, looking for turkey eggs, for there is a big flock roosting in the vast local woods.
My Lot 10,000 Years After the Extinction of Homo sapiens
There is no trace of my house, at least on the surface. Bricks, metal, and plastic are buried under several feet of sediment. The surrounding landscape is an open woodland consisting of loblolly pine and sand laurel oak–the species that have long co-dominated this belt of fall line sand hills. The trunks on many of the oaks are 6 feet thick, but the poor soil keeps them from growing very tall. Fire and megafauna foraging maintain a grassy understory between the widely spaced trees. The climate is beginning to gradually sink into an Ice Age, but the change is imperceptible to the great herds of horses, long-horned cattle, bison, wild boar, and deer that live in the vicinity. Jaguars long ago joined the cougars and wolves in hunting the hooved animals. The wolves descend from coyote x dog hybrids. They evolved to a larger size that helps them bring down larger prey. Bears are abundant, but feral cats, along with other small predators such as raccoon, fox, and opossum are less common than they were in anthropogenic environments because the larger predators keep their populations in check. It’s almost like the Pleistocene again.