Where I live in south-central Pennsylvania, farmers and outdoor enthusiasts are well aware of new invasive species posing a threat to our forests and crops, like the Emerald ash borer and the Spotted lanternfly. It is easy to be lured into a myopic idea that the migration of fauna and flora mostly affects humans today and that earlier generations experienced such changes only gradually.
But this is not true, as studies in historical biology from Ancient Roman Britain show. In the first century, where the demands of Empire spread, Roman elites remade the landscape in the shape of new agricultural environments in order to supply the military and imperial annona, a sort of tax/tribute in crops versus coin.
In Britain this meant the radical intensification of cereal culture — meaning the creation of great numbers of fields and farmers, similar to the one shown here on a stone relief from the Western European continent. The second slide features a lot of Roman farming tools, many which originally entered Britain for the in the first century CE. Before this, for instance, Britain had never had hoes. Hitchhiking along for the ride between the established warmer parts of the Empire and chilly Britain came damaging insect species such as granary weevils, rust-red grain beetles, and saw-toothed grain beetles. These bugs — then as now — destroyed crops and could not have existed without the above-ground storage units the Romans introduced.
When the Empire fell apart at the end of the fourth century in Britain, so too did the ecology of invasive grain-destroyers. Intensive cereal production, large above-ground storage units, and bugs — all disappeared.
Source(s): Robin Fleming, _The Material Fall of Roman Britain_, UPenn Press, 2021, 38-42.
