Habitat Fragmentation May Impact Meadow Plants by Increasing Disease Vulnerability

It turns out that habitat fragmentation may be having more negative impacts than once thought. Researchers have found that a connected environment actually increases disease resistance in wild meadow plants.

The researchers surveyed more than 4,000 Plantago lanceolata meadows and their infection status by a powdery mildew fungus. In the end, the scientists created the world's largest database on disease dynamics in wild plant populations.

"Contrary to expectations of ecological laws, there was less disease in those areas of the landscape that supported dense meadow networks," said Anna-Liisa Laine, one of the researchers, in a news release. "This suggests that disease resistant has increased in these areas where there's more gene flow between the plant populations. This hypothesis was confirmed in a laboratory study where we measured a higher susceptibility to infection in plants originating from isolated meadows. The results are a powerful demonstration that while plants stand still, their genes don't. Landscape structure strongly impacts how pollen and seed travel, shaping the genetic diversity of local populations."

In nature, either the host populations of the diseases are small and fragmented or, when abundant, they have evolved higher levels of disease resistance. It's possible that gene flow between meadow populations that are nearby could aid in disease resistance.

That said, the mechanisms that keep diseases in check in nature are poorly understood. Yet a lot can be learned by studying disease spread in these wild populations. More specifically, scientists have learned a bit more about disease spread by studying this meadow network. This, in turn, can help with crops and other agricultural environments where rapid disease spread can lead to the loss of plants and, subsequently, food.

The findings are published in the journal Science.