About Us

We are members of the Andrew Gonzalez lab , in the Biology Department at McGill University.
Montréal, Québec, Canada

Wednesday, September 14, 2011

Spare it, Share it, or Both? Balancing agriculture with biodiversity conservation

How can we feed the growing human population while conserving biodiversity?

A recent paper in Science by Ph
alan et al. makes the case for establishing strict forest preserves and intensifying agricultural practices in the surrounding matrix.The paper compared two biodiversity-management strategies for agricultural landscapes:

1) Land sparing - set aside strict forest preserves while intensively farming the remaining land

2) Land sharing - adopt low-intensity, biodiversity-friendly farming across the landscape

The study correlated crop yields with densities of 341 bird and 260 tree species in India and Ghana across an agricultural intensity gradient (ranging from “diverse low-yielding mosaic agriculture to large-scale high-yielding monocultures”). They showed that, for a given amount of food production, most species (rare and common) would have higher populations under land sparing than land sharing.

There are caveats* to the conclusion that land-sparing is better for biodiversity. The authors point out that the conclusion depends on local context and may not hold for all species in all regions. The study did not discuss "how" to spare land in terms of building a network of forest preserves.

The agricultural landscape surrounding Montreal represents an opportunity to test this question. The image to the left highlights the fragmented forest patches (green) embedded within an agricultural matrix (yellow) and interspersed urban areas (gray). Perhaps this landscape could showcase an intermediate approach whereby biodiversity-friendly farming practices form the matrix around forest preserves and more intensive agriculture. In this model, eco-agricultural methods in the matrix and forest corridors would facilitate species dispersal among forest fragments to enhance biodiversity conservation, ecological functioning and ecosystem services across the forest network.

Certainly we need to apply cross-disciplinary biodiversity science that integrates ecological, economic, humanitarian and social interests to achieve the appropriate balance between land sharing and land sparing.

Reference: Phalan, B., Onial, M., Balmford, A., Green, R. E., Reconciling Food Production and Biodiversity Conservation: Land Sharing and Land Sparing Compared. 2011. Science. 333, 1289-1291.

*I haven't discussed implications of land sparing on food accessibility and security.


  1. Intensification vs. extensification is a big debate in agricultural land management. Good to see some numbers on it, although you're right - different areas might fare better under different scenarios. Thanks for the post!

  2. Yes, there is also lots of parallels with forest management. The TRIAD approach to forestry combines extensive and intensive forestry practices with strict protected areas. This approach is being actively promoted by, among others, Christian Messier's lab at UQAM. As with the agricultural applications though, there is a lot more research needed on the implementation details and the best ratio of intensive, extensive, and protected areas.

  3. Yeah… species extinctions are a natural process and it’s likely that we’re simply coming toward the decline of the Bird and Mammal dominated biosphere and into a new phase. It is also quite likely if you take a thorough look at the fossil record, that the highest of those species that have developed so far, is meant to take over the biosphere and it seems to me that it’s the human species that fulfills this role. That is, if we choose to not act like animals and be intelligent. Population caps or population reduction is a desire for the extinction of the greatest creation the biosphere has been able to produce; humanity. It also is rather peculiar to me, and seems a strange coincidence that a bunch of uppity oligarchs like Prince Philip and Sir David Attenborough are pushing this green population control stuff. I think it may be that they only want them and their families to live on planet earth so they can have there way with a bestial mankind and also with donkeys like their buddy Bertrand Russell… hmmm… Well according to this video and James Dwight Dana, the entire biosphere had conspired to create a species capable of cognition, and the intentional stifling of this cognitive power is going against the intended design of the creator. Maybe all this “naturalist”, “green” anti-development/anti-progress stuff is just unnatural Imperial Brainwashing…?