Place two of the great conundrums of our time — conservation and food security — as trade-offs and you’re bound to generate some controversy. The current hot debate on “land sparing v. land sharing” does just that, in an attempt to find the best balance.
The debate goes like this:
Land Sparing: “People need to eat, so conservation organizations should promote intensified food production in some places so we can totally protect other places (even if it means less wildlife in agricultural lands).”
Land Sharing: “People need to eat, so conservation organizations should promote wildlife friendly agriculture (even if it means a larger footprint in agricultural lands).”
Are you asking, “Does this simple dichotomy make sense?” Then check out a new review paper on this debate by Fischer et al. in Conservation Letters. They are concerned that the debate has become too polarized, and could be more productive if we take a step back and consider how to stop talking past each other, frame the debate in a constructive way, and be clear about assumptions and value systems. Towards this end, they lay out five friction points in the debate, and how to move forward on each.
It’s not just about food
Here I am only taking on their first friction point: the debate has gotten mired down with a focus on food production — whether that be the raw tonnage of food produced, or food security, or food sovereignty. They suggest we take a step back to the fundamental issue of “land scarcity” because, “effectively, land use is the object of choice, and much of what is grown on land is not actually used to feed people (e.g., energy crops or fiber).”
I would add that we should expand the discussion to include not just biodiversity, but a range of conservation values such as carbon sequestration, hydrology, and other ecosystem services. In other words, this debate can help us think through how a defined landscape can produce a range of necessities (food, fiber, and fuel) while maximizing conservation values.
With that frame, let’s follow Fischer’s suggestion and think about another product of the land: fiber, or wood products. The wood products sector is the primary gatekeeper to the earth’s remaining undisturbed forests, so it deserves more attention than its 1% of global GNP might suggest.
In the tropics, where decisions about land sharing vs. sparing are most dynamic and urgent from the perspective of both biodiversity and human benefits, about 20% of remaining native forests are subject to low intensity selective logging. There’s a heated debate underway as to whether we should bother working with loggers to reduce selective logging impacts — an area where there’s a lot of room for improvement but results are hard to measure. Fortunately new methods are emerging to verify lower impact logging, so that the conservation benefits of “sharing” nature with timber production can be carefully tracked. Meanwhile, a much smaller but rapidly growing portion of forests are being converted into high intensity tree plantations, which are usually exotic species, as revealed by a new global deforestation study.
Local interests in livelihoods from native forests can help protect forests
Which is the lesser of conservation evils, per unit of wood fiber produced? On the one hand, selective logging operations in native tropical forests often are responsible for building the first access roads into remote forests, and thus can be the first step towards forest conversion in some of the last vast tracts of native forests.
On the other hand, evidence is mounting that where logging companies have legal tenure, they function as barriers to deforestation — as or more effective than protected areas (see Gaveau et. al. 2013 and as reviewed by Griscom & Cortez 2013). The effect seems to be particularly strong when logging is community-based, probably because forest-based community owned companies have a longer-term interest in their site-specific forest business model than multinational companies.
Further, while conventional selective logging in tropical forests may not look pretty, a recent meta analysis concluded that these selectively logged forests retain over 80% of their biodiversity and three quarters of their carbon. Both outcomes could be measurably improved with better logging practices as mentioned above. To the extent that low impact selective logging can be done right, maintaining reasonable levels of timber production with very low biodiversity and carbon impacts, all while resisting deforestation, this “land sharing” approach to forestry should be a priority conservation strategy where protection alone is not viable.
Scale and location matter
Of course, it’s not that simple. While much of the forest landscape seems to be quite resilient, certain areas — such as riparian zones, steep slopes, old growth forests, or places with endangered species — can be very sensitive to even limited impacts. So, we should probably lean towards “sparing” those places from logging.
As Fischer et al. point out, there’s also the related question of scale. In the case of timber production, I have been talking about a large scale where we can contrast two very different production systems: selective logging across extensive native forests (sharing) vs. smaller areas converted to high intensity single species plantations combined with protected forest patches (sparing). And I offer the hypothesis that “sharing” native forests with selective logging offers a comparatively stronger conservation outcome.
But nested within this “sharing” selective logging system, a more fine-grained sparing vs. sharing debate has emerged with a study in Borneo by Edwards et al. It goes like this: to what extent should we “spare” the more sensitive parts of the logging landscape, while meeting the demand for timber production with higher-intensity selective logging (well short of conversion to plantations)? Edwards et al. conclude that within the context of “sharing” native forests with selective logging, it makes conservation sense to spare patches of old growth forest while nudging up selective logging intensity elsewhere.
Ready for one more twist? What if global demand for timber simply cannot be met with lower-intensity selective logging of native forests, without expanding into the sensitive landscapes mentioned? Even if we decide to promote selective logging with old-growth set asides as the best chainsaw juggling act in many landscapes, we likely still need a triage plan for identifying some places that will be converted to intensive plantations.
Ok, so it’s complicated. Fortunately, there is a growing toolbox of sophisticated conservation planning tools that can handle this sort of complexity (like these). We can use these new tools to answer complex “land sharing vs. land sparing” questions with land use options that find a better balance between products we need and conservation values we can’t bear to loose.
If we can do this in a way that respects the different value systems of critical stakeholders in a given landscape, then I think we can respond to Fischer et al.: the debate really is moving us forward.
The paper: Fischer et al. 2014. Land sparing vs. land sharing: moving forward. Conservation Letters. In Press. Early view available at: http://onlinelibrary.wiley.com/doi/10.1111/conl.12084/pdf