Sharing or sparing land for nature?

A new ecological study of novel human-influenced ecosystems should change the debate about whether farmers should be sharing land with nature or sparing land for nature.

Joseph Essissima is a cacao farmer I met in Cameroon about a decade ago. He had half a hectare of cacao trees that he planted 60 years ago. In his piece of the forest he had kept plenty of the natural trees to provide shade and fruit. The IITA forest ecologist with us, Jim Gockowski, said these plantations have almost as many species as a natural forest. Photo: Fred Pearce

Sparing land for nature

Lately the sparing-v-sharing argument seems to have been going the way of the sparers.  Much discussion has centered on a critique by Cambridge University’s Ben Phalan two years ago on “how to meet rising food demand at the least cost to biodiversity.”  From two studies in Ghana and India, Phalan found that “more species were negatively affected by agriculture than benefited from it” and that “land sparing is a more promising strategy”.

The take-home lesson was that we need more high-tech, high-yield farms and some solid fences between them and land strictly protected for nature.  In other words, forget agro-ecology, it won’t deliver.

Lots of people like this.  Conservation organizations get their own land to play with, often part-funded by agribusinesses, who are equally happy to have greens off their backs.   It also fits an emerging agenda for commodifying nature through carbon trading and habitat banking, a strong theme at last year’s Rio+20 summit.

Whether the sparing strategy makes sense for nature depends, in part, on whether the choice is a zero-sum game.  If agribusiness stimulates a land rush into nominally protected areas then the sparing proves illusory.

Novel ecosystems

But it also depends on whether we are seeing nature right.  And a major new book by ecologists and biogeographers on Novel Ecosystems, edited by Richard Hobbs of the University of Western Australia and others, suggests that conventional conservation is in denial about the ecological value of farmed forests and other agro-ecological landscapes.

Ecologists, the authors argue, systematically dismiss novel ecosystems – defined as ecosystems altered by humans and containing non-native species.  They see them at best as valueless degraded versions of pristine habitats, and at as worst dangerous, because they contain non-native species that could spread.

But in the real world, most ecosystems are novel.  Apparently pristine rainforests are frequently secondary growth on ancient farmland, Erle Ellis of the University of Maryland Baltimore County argues in the book.

Typically too, even the most invaded and most novel ecosystems have more biodiversity than what went before, since extinctions are rare and are almost always outnumbered by new arrivals.   That applies at all scales from well-known “victims” of alien invasions like New Zealand to agro-ecological systems like the canopy coffee farms of Cameroon.

Sharing land with nature

Hobbs and colleagues argue that, except in the rare cases where alien species go on the rampage, conservationists should embrace such ecosystems, rather than shun them.  And that means embracing agro-ecological systems, which are both major sources of forest products and rich in biodiversity, both native and alien.

Christian Kull of Monash University in Australia recently banged the drum for novel forest-based farming systems such as the rubber gardens of Indonesia, the cacao farms of Cameroon and rice smallholders in Madagascar.  As he wrote in the journal Environment, these systems “blur boundaries between human and natural, native and non-native, production and conservation”.  He called them “melting pots” – a deliberate riposte to the “hot spots” of biodiversity that conventional conservationists most treasure.

The new thinking about novel ecosystems should also change how we think about ecological restoration on abandoned land, such as former plantations.  Ecologists mostly want to recreate a past “pristine” habitat.  They usually start by trying to eliminate alien invader species.  But if the idea of pristine is usually bogus – and in any case usually unattainable -- that should open the door to other options, say Hobbs and colleagues.

One option would be to give nature its head.  The model here is Puerto Rico, a US island territory in the Caribbean and one of the few areas of the tropics where there has been major recent reforestation.  Following the abandonment of sugar-cane farming, forests have regrown across half the island.

The new forests contain many alien species, brought to the island by humans in past centuries.  Most interesting from an ecological point of view, aliens such as African tulip trees have been critical to the reforestation, pioneering regrowth and bringing native birds, reptiles and insects with them.  It couldn’t have happened without them, says Ariel Lugo of the International Institute of Tropical Forestry, who has charted this rewilding.

Another option on abandoned plantations, of course, would be to assign the land for agro-ecology of the kind that the plantation may originally have replaced.  It happens by default sometimes, when the plantation fences come down and nobody puts up new ones.  But the case for it as a sustainable and desirable new land use is rarely made.

That is a pity.  Especially now.  For, if there is no pristine nature left, then all ecosystems are novel and all are of potentially equal worth for conservation.  Seen through the prism of novel ecosystems, agro-ecology is not a poor-man’s substitute for either the conservation of “pristine” habitat or for high-tech farming.  It is both productive and of high conservation value.

The case for sharing, rather than sparing, suddenly got stronger.


About the Author:

Fred Pearce is a journalist and author based in London, UK.  He writes regularly for New Scientist magazine, the Guardian newspaper and Yale e360 web site.  His books include PeoplequakeWhen the Rivers Run Dry and, mostly recently, The Land Grabbers.


For updates follow us on @WLE_CGIAR and on Facebook.


This is a very interesting debate. The land management approaches that will not avail conflict with humans are the best. The nature is here for human development and what is required to make sure it is used in sustainable approach. I agree with novel ecosystem and agro-ecological landscape approaches as these will not bring conflict with the users/humans and hence enhance the nature sustainability

Great post though I do have a couple of bones to pick. The argument that ecologist see no value in agroecosystems is rapidly evolving and an unfair (and largely out-dated) stereotype in my opinion that moves us backwards rather than supporting the push for integrated landscapes that many ecologists (including the authors of the reference) have been promoting. See the Landscapes for People Food and Nature Initiative ( for one example; at the risk of tooting my own horn, see also the work on Ecology and Poverty edited by Ingram, DeClerck and Rumbaitis del Rio. Anyone looking at the ecological literature over the past 20 years will see a surge in ecological work that both considers the conservation value of agricultural landscapes (see the early work on Countryside Biogeography from Daily, Harvey, and others); as well as growing work on the functional contribution of conserved space on the provision of ecosystem services ranging from pollinator services (Kremen and many others), pest control (Tscharntke, Klein and others); human diseases such as lyme disease (Ostfeld and Keesing). In conservation biology this debate has also been considered largely settled with the recognition that conservation will fail under the sparing scenario in the face of climate change - maintaining space including connectivity options for wild biodiversity in managed landscapes is fundamental to protecting many of these species. While the topic is new, and some ecologists are demonstrating a healthy dose of skepticism, to say that ecologist systematically dismiss the idea ignores that ecologists originated the idea, and have been exploring it with growing interest over the past three decades.

What is also clear however is that novel ecosystems, and agricultural landscapes, while creating significant space for biodiversity conservation, are not a panacea; many of the species that conservation groups care deeply about simply will not survive in these landscapes. There is a value in wild places that should be maintained in the dialogue.

A central question related to this is sharing or sparing yes, but at what scale?? Its given that at a global scale, we are already operating in a sharing scenario. What about the field scale? Agroforestry systems which "share" crops with trees provide significant conservation benefit compared to disaggregating the two (sparing). We might also ask what the consequences to production systems are when we "spare them" with clear warning signs coming from the pollinator crisis in California - how much does agriculture depend on conservation - a growing body of research suggest much more than we think. What happens to other critical ecosystem services provided by agriculture under a sparing scenario? What about landscape scales? Conservation certainly benefits when large tracts of land are protected, but unless the land in between is shared, these reserves are threatened to become islands of conservation threatened by external pressures. Conservation depends on shared space in agricultural landscapes.

The CGIAR Water Land and Ecosystems Program sees a clear benefit of considering these issues at the basin scale by considering how different portions of basins contribute to conservation value, production values and livelihood values. The advantage of working at this scale is that it permits a more nuanced look at sharing and sparing. At the basin scale identifying conservation areas that not only provide a critical conservation space, but also provide important hydrological functions (flood control, flow regulation, fisheries, climate mitigation) is possible); as is identifying areas where agricultural potential is greatest. More importantly it allows us to begin to map out the interactions between the two - for example the role of conservation areas in providing water for agriculture at basin scales, the role of forest fragments in providing agroecological functions at landscape scales, and the role of field margin conservation and live fences in providing both connectivity for wild biodiversity, and pollination/pest control functions at field scales.

The clear advantage of the notion of sharing is exactly in its capacity to focus on interactions between agriculture and conservation, with a critical eye to the trade-offs; but probably more importantly magnifying the synergies.

Sparing or sharing, great article, and Fabrice arguments are compeliing and convincing, the bottomline is any system that will put food on the table while maintaining the ecosystem for future generation is very welcome. Talking about natural habitats, alien species, invasive species etc for me is not the issue because man the landscape as we see it today have to be a result of alternate uses and changes. what we consider indegenous or natural landscape today is certainly not the natural ecosystem as it was from the begining. If not man, it will be other natural factors changing the landscape and bringing in alien or invasive specie. As an amateur ecologist and from what I see around me here in Sahel Africa, I believe that nature has a way of rejuvenating itself, the issue now is whether we are giving nature enough time and space for this rejevenation.

Interesting and informative post. Thank you for your effort. "Sharing or sparing land for nature?" - interesting title Fred. Thank you for the article Fred.

Add new comment