2021
Lenore Fahrig
Researcher challenges ‘bigger is better’ approach to land protection
2021
Researcher challenges ‘bigger is better’ approach to land protection
How land is designated for protection, whether in small or large parcels, may not sound controversial or complex, but it is. And it’s central to the work of Dr. Lenore Fahrig, a Carleton University biologist and 2021 winner of the Guggenheim Fellowship.
“For example, say you are going to conserve 100 hectares of forest. Is it better to conserve one big 100-hectare block or 10 small blocks that add up to 100 hectares? In the 1970s, the prevailing thinking was that one big block would be better.
“But people tested this and found more species in 10 small blocks than in the one big one,” says Dr. Fahrig.
Tackling this question stems from her research on the impact of landscape structure on abundance, distribution and persistence of organisms. Since landscape structure is strongly affected by human activities such as forestry, agriculture and development, the results of her research are relevant to land-use decisions.
The Guggenheim Fellowship will support a research project looking at the effects of habitat fragmentation on several species. This study is connected to Dr. Fahrig’s long-term research on the effects of habitat fragmentation.
Her studies include examining government policies on protecting natural habitats. “They tend to reflect the idea that bigger is better,” she says. “This is a problem because if we assume that small parcels of habitat have low value for biodiversity, we can end up with thousands of small patches that have no protection, even though they host a great deal of biodiversity,” she says. “If they are destroyed the loss to biodiversity is huge.
“There is a lot of intuitive thought about larger species or those endangered doing better in a larger block, such as species that do better in the interior of a forest. This seems to make sense because if you have 10 small blocks you have more of the edge and less of the interior area of the forest that those species need. Some people think that means there would be more species in a bigger block than many small ones.
“But is that true? People are extrapolating from a small-scale observation. They take that pattern comparing species at forest edges vs. the forest interior and scale it up to make an inference about what we should see across a whole region. The problem with that is that there are all kinds of other factors that come into play that could counteract that prediction. And this has not been tested.”
Some government policies only protect large parcels.
“The problem is that in human-dominated parts of the world, you’ve already lost 80 per cent or more of the natural habitats and the remaining spots are very small. So if you aren’t protecting small parcels you are saying they have no value, when we really need them and in fact they can contribute a lot to biodiversity.”
This research is important because of the global biodiversity crisis, she says. “It’s hard to know how many species have already gone extinct because of human activity.”
She hopes her research can help inform responses to the crisis.
