Are all ecosystems meant to be forests?

The implied answer to this question, embedded in the way that the increasingly influential sustainable landscapes movement describes itself, is apparently “yes”.  The title of one of the leading initiatives—the Global Partnership on Forest and Landscape Restoration (GPFLR)—is telling.  Presumably, types of ecosystems other than forests are captured under “…and Landscape…”, but if that is the intention, then clearly the people who were in the room at the time the GPFLR was created considered forests to be what is really important.

Similarly the Bonn Challenge—the global effort to restore 150 million hectares of degraded land—could be understood as applying to land of any ecosystem type that has been degraded; but when you examine the language and the metrics and the approaches, it becomes clear that it’s the restoration of forest landscapes that is the priority.

The status of rangelands as second-class ecosystems is reinforced by the very way that they are often defined as a residual, “left over” category:  after the forests and the wetlands and the crops and the urban spaces and the water bodies are all identified, everything else can be put under the heading of “rangelands”.  This is more than just academic nitpicking about definitions.  Treating rangelands as a residual category reinforces the common assumption that the rangelands, grasslands and deserts of the world are that way because people have mismanaged them:  if left alone, or if managed properly, they would become forests.  Treating rangelands as a residual category contributes to the kind of thinking which assumes that more trees and bigger, healthier forests are the preferred option for sustainable landscapes: “That place is a ‘rangeland’ because it lost its trees, so let’s help the trees to come back”.

Ecosystems in their own right

The ecology of rangeland and desert ecosystems, however, tells a different story.  In many of these regions the rainfall is too little and too variable to support significant forest cover.  One of the best examples of the misconception is the sentiments I sometimes hear expressed about the Sahara Desert: “One day, when human beings have learned to live more sustainably; when the livestock owners have stopped overgrazing and removed goats from those landscapes (you know, goats always destroy the environment); when we have planted trees to attract rain and hold the soil—then the whole desert could become green again.”

The truth, however, is that the Sahara Desert has been a desert far longer than humans, and livestock owned by humans, have been able to affect it.  Where the northern Trade Winds and the southern Trade Winds converge, air rises and cools, and you get rain.  This is the tropics.  After that air rises and loses its moisture, it has to come back down somewhere.  It mostly comes down between 30 and 35 degrees north latitude and 30 and 35 degrees south latitude.  It is in these two bands of latitude that most of the world’s great deserts are found:  the Sahara, Arabian, and Sonoran Deserts in the northern hemisphere and the Atacama, Kalahari, and Australian Deserts in the southern hemisphere.  Pastoralists and their goat herds are not to blame for this global atmospheric circulation pattern.

In some of the other rangeland regions of the world—a large portion of Africa’s savanna landscapes for example—the rainfall is high enough that the area could, in theory, support forests.  A common assumption is that such areas once were forests but were transformed by human beings, and that contemporary human activity—particularly grazing by livestock and setting of fires—is preventing these areas from becoming forests again.  The fossil evidence says something different: the spread of savanna ecosystems, and the roles played by natural fires and by wild herbivores in making that happen, predated the domestication of livestock and the ability of human beings to control fire by millions of years[i].  Savannas are not former forests that humans degraded—they are natural ecosystems in their own right and have been so for millions of years.

 

The danger in assuming that rangelands are degraded forests

The assumption that rangelands are degraded forests is resulting in healthy rangelands being targeted for “restoration” through afforestation[ii].  The danger in this is that, in the name of restoration, pastoralists and ranchers will be alienated from their lands and their livelihoods, rangelands will be fenced and “protected”, and even that they will be dug up to plant trees.

There are various environmental reasons that could be offered for doing so, but let’s take climate change mitigation as one example.  Around the world, deforestation is rampant, and one of the pillars of the fight against climate change is sustainable forestry—avoiding the greenhouse gas emissions that result from deforestation, and actively capturing carbon through reforestation.  A problem arises when this strategy to applied to rangelands.  Healthy rangelands already store a huge amount of carbon.  They may account, in fact, for up to 30% of the world’s terrestrial carbon storage[iii],[iv].  Rangelands, however, are more humble about their carbon storage than forests, doing most of it underground in root systems, hidden from remote sensing satellites and National Geographic photographers.  If we are truly concerned about mitigating climate change, there are better things on which to spend our money and effort than attempting to “restore” rangelands that are already healthy and sustainably managed.

Rangelands are not degraded forests. Healthy rangelands store a huge amount of carbon in the soilDon’t get me wrong—I have nothing against trees and forests.  And the GPFLR and the Bonn Challenge are valuable initiatives.  But sustainable management is needed for wetland, tundra and rangeland landscapes as much as it is needed for forests, and attempting to convert these kinds of ecosystems into forests should not count as “restoration”. 

Another initiative that is part of the sustainable landscapes movement—the Global Landscapes Forum—has also focused largely on forests.  Now, however, it is taking small steps in the right direction[v].  But in all of these initiatives, there is still a long way to go to bring rangelands into the discourse on its own terms.

 

Bringing rangelands into the sustainable landscapes movement

If the sustainable landscapes movement is to avoid misdirected actions, we need three things:  objectives that reflect the diversity of ecosystems, metrics that are adapted to the diversity of ecosystems, and methods that are designed for the diversity of ecosystems.

We need objectives that reflect different ecosystem types because sustainable landscapes should not be equated with sustainable forests, and landscape restoration should not be reduced to planting trees.

We need metrics that are adapted to the diversity of ecosystem types because indicators have a way of becoming the objectives and of driving actions.  Mechanisms such as REDD that rely on verification require clear metrics, but such metrics are easier to create for forests than for rangelands.  Satellite-based remote sensing methods are well developed for detecting greenness, above-ground biomass and percentage tree cover, but none of these indicators are helpful measures of the health of rangeland ecosystems.

We need methods that are designed for different ecosystem types because the communities that live, work and create their livelihoods in different ecosystems are different.  While there are some commonalities among all communities whose culture and livelihood are tied to making a living from the land, there are also critical differences.  The ways that pastoralist communities organize themselves, the norms and values that they emphasize, and the challenges that they face are often distinct from those of farming communities.  And farming communities and pastoral communities can also each be very different from fishing communities, which are also different from forest communities.  Methods need to be designed to reflect the biophysical and social characteristics of where they will be applied.

This is certainly true of landscape approaches, which, if they are to be effective, need to look different in pastoral rangelands than in landscapes dominated by farms and forests.  (I expect that I’ll want to explore this in a future post.)

If rangelands are to be fairly reflected in the global landscapes movement, we need objectives, metrics and methods that are adapted to their contexts.  The policymakers, the practitioners and the experts involved in land and ecosystem restoration need to understand rangelands as well as they understand forests.  We need to get the policies right, and we need to get the details of initiatives such as the Bonn Challenge right.  But what is more fundamental than any of these needs is to enable meaningful participation in decision-making from the people who live in these rangelands—the pastoralists and ranchers who are their stewards—, to draw on their knowledge, and to learn from their cultures and ways of managing the land.  If we can do this, then we’ll be well on our way to ensuring that our objectives, metrics and methods are adapted to the contexts where they’ll be used.

References

[i] Bond, W., & Zaloumis, N.P. 2016. The deforestation story: testing for anthropogenic origins of Africa’s flammable grassy biomes. Philosophical Transactions of the Royal Society B: Biological Sciences, 371(1696), 20150170. URL: https://www.researchgate.net/publication/303504175_The_deforestation_story_Testing_for_anthropogenic_origins_of_Africa%27s_flammable_grassy_biomes

[ii] Veldman, J.W., Overbeck, G.E., Negreiros, D., Mahy, G., Le Stradic, S., Wilson Fernandes, G., Durigan, G., Buisson, E., Putz, F.E., & Bond, W.J.  2015.  Where Tree Planting and Forest Expansion are Bad for Biodiversity and Ecosystem Services. BioScience, 65(10): 1011–1018, https://doi.org/10.1093/biosci/biv118.

[iii] Schuman, G.E., Janzen, H.H., & Herrick, J.E. 2002. Soil carbon dynamics and potential carbon sequestration by rangelands. Environmental Pollution, 116, 391-396. URL: https://www.researchgate.net/publication/11536949_Soil_carbon_dynamics_and_potential_carbon_sequestration_by_rangelands

[iv] Neely, C., Bunning, S., & Wilkes, A.  2009.  Review of evidence on drylands pastoral systems and climate change Implications and opportunities for mitigation and adaptation. Land and Water Discussion Paper No. 8.  Rome:  Food and Agriculture Organization of the United States.  URL: http://www.fao.org/3/a-i1135e.pdf

[v] Bringing rangelands into the sustainable landscapes agenda: Report on discussion panel held at the Global Landscapes Forum Event, Forest and Landscape Restoration in Africa—Prospects and opportunities.
and
A 5-minute started on rangelands and why they matter.