Leaf Litter

Leaf Litter Talks with Richard Hobbs

Australian environmental science professor and co-author of “Ecological Restoration and Global Climate Change” in the journal Restoration Ecology, Richard J Hobbs shares thoughts and advice on incorporating climate change in ecological restoration.

By Amy Nelson

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Professor of Environmental Science, Murdoch University School of Environmental ScienceWestern Australia and Editor-in-Chief, Restoration Ecology

Professor Richard J Hobbs is an Australian Professorial Fellow in the School of Environmental Science at MurdochUniversity in Western Australia.  From an initial basis in plant ecology, his interests developed to span multiple scales of organization and several broad fields, including restoration ecology, conservation biology and landscape ecology. He has mostly been involved with the detailed analysis of the dynamics of fragmented systems, and in particular in woodland dynamics and restoration, but this work has also extended more generally into the management and conservation of altered ecosystems and natural resource management. His approach is inter- and trans-disciplinary and his research group is currently involved in a wide array of projects . He is currently working on a project entitled “Setting and achieving realistic restoration goals in human-dominated ecosystems. Richard is also the Editor-in-Chief of the journal Restoration Ecology, a publication for which he co-authored the article entitled “Ecological Restoration and Global Climate Change” in 2006. 

What prompted you to write the article “Ecological Restoration and Global Climate Change” in the journal Restoration Ecology last year?

Several of us in the SERI Science and Policy Working Group thought that it was important that we started putting some serious thought into what rapid environmental change, and in particular climate change, meant for restoration. I think there has always been the assumption that restoration aimed to put back something that was there before; however, rapid climate change might mean that this becomes increasingly difficult. If that is the case, what do we do about it, and what are the alternatives?

In the article, you and your fellow authors recommend that restoration targets go beyond historical references in order to a) ensure or restore the production of ecosystem goods and services and/or b) mitigate and reverse climate change.

Looking at the results of our reader survey, people are heeding that recommendation. 54% of Leaf Litter readers who responded to our survey say they are taking climate change into account in a current ecological restoration (ER) project. Some are doing so in order to protect natural capital (e.g., taking sea level into account for a shoreline restoration). Others are more focused on the anticipated carbon sequestration resulting from their project. Few indicated they are applying both modes of intervention (natural capital and climate change mitigation). Is our sample reflective of what you are seeing in terms of ER practitioners incorporating climate change into their projects? 

I think that many people are paying some attention to climate change, but I have not seen much evidence that it is actually changing what people actually do or what their overall aims are. Partially, I think this may simply be because it is very difficult to work through what a suitable response might be. But partially also, a lot of people are still in denial or unwilling to move away from the principles that have developed surrounding what are good things to do in restoration. For instance, there’s the question of whether to use local provenances of plant species in restoration. The accepted wisdom is that it is always preferable to do that wherever possible, since the local provenances are likely to be the best suited to the site. However, if we are to build resilience into the restoration, maybe we need to start thinking differently and incorporating a mix of provenances.

Based on your observation and experience, where do most ER practitioners go wrong when it comes to attempting to incorporate climate change into their work?

By not considering it at all!! That’s not to belittle what’s going on – it’s simply a fact across the board that many people would prefer to think that climate change is not occurring and that we can carry on as normal: not just in restoration, but in all aspects of life from our governments down. Having said that, I think we need a considered response which does not go overboard: exactly how best to incorporate climate change remains, I think, an open question that requires some serious thought from both the academic and practical perspective. In other words, practitioners have as much, if not more, to contribute to the debate as scientists and other academics.

The topic of invasive species often evokes strong emotional responses. What has been the reaction to what you say in your 2006 article about how we look at invasive species among scientists and practitioners? 

As you rightly point out, invasive species are a highly emotive topic. People who have seen first hand the impact that invasive species can have on ecosystems and native species know that they are a serious issue and are often the prime targets in restoration projects. On the other hand, there is a real tide of popular literature at the moment which suggests that the whole push against invasive species is misguided at best and xenophobic and self-serving at worst. I think this latter perspective is a bit extreme. However, the question of invasive species and their place in the ecosystems of today and tomorrow is a vexed one. On one hand, removal of weed species or feral animals which completely transform ecosystems is often an essential part of restoration. On the other hand, we now have so many non-native species in many systems that we can’t hope to deal with them all. Hence we may have to accept that future ecosystems are going to be mixes of native and non-native species, and that these “novel” ecosystems are here to stay. This is, of course, an anathema to those who believe that the native ecosystem is the only worthwhile goal for conservation and restoration. In the end, this is not only a scientific question but one which taps into the deeper ethical and value-based aspects of our relationship with the environment.

The article mentions moral dilemmas associated with climate change and ecological restoration. One such topic is assisted migration. What are your thoughts on both assisted and unassisted migration? How much of a “determining agent” of change do you think we should be, when it comes to ecological restoration in the midst of a changing world?

Boy, you ask some pretty profound questions! This one gets right to the heart of the whole problem of moving away from trying to restore past ecosystems to trying to equip systems to cope with the future. When and how should we intervene?  Do we let “nature take its course,” or do we step in and try to preempt problems before they arise?  If we are to facilitate the migration of species, how best do we do it?  For unassisted migration to occur there needs to be a certain amount of connectivity across the landscape – and of course this is increasingly lost in today’s urbanizing and developing landscapes. It is possible to foster increased connectivity, but it requires a landscape and regional approach. And we’re only beginning to get a handle on what different species require to move across the landscape. Where that approach is not possible, do we then get into the business of moving species across the landscape ourselves? If we do, how do we figure out where to move things to? How do we decide when to act? And what about the species already present in the destination?  What seems like a relatively simple issue if you just look at projected range shifts under climate change becomes a much more difficult thing to figure out when you start thinking about the mechanisms and decision points needed. Again, this question has some pretty important ethical and value components which need to be worked through.

The article cautions against “overly prescriptive” conservation management. Do you think most current conservation management programs are too restrictive, in terms of enabling an ecosystem’s ability to change?

Many conservation policies and management programs are very static in their outlook and focused on conserving species and ecosystems in particular states in particular places. We know that ecosystems are not static entities, even without climate change. Basing your entire conservation strategy on existing reserves is likely to be a recipe for failure; of course, on the other side, the opportunities for more broadly based conservation are diminishing in many parts of the world as more and more land becomes transformed. The answer is not easy – a more broadly-based landscape-scale approach which incorporates different land uses and ownerships and which depends on cooperation among different agencies, NGOs and community groups. But it can work. In fact, I’d suggest that it will have to work if we want to ensure effective conservation into the future.

You have experience throughout the world. Where do you think people are most ahead of the game in terms of incorporating climate change considerations in their ecological restoration and conservation planning efforts? Does one particular project come to mind?

I think climate change is just one factor that has to be incorporated into a more realistic approach to conservation and restoration. Recognizing the dynamic nature of ecosystems is a key to furthering this, as is moving away from an idealized view that it is necessarily easy or desirable to aim for some past ecosystem state. Here in Australia we generally take a pretty pragmatic view of these things and there are various projects around the world where there is an overt consideration of the need to manage for resilience. For instance in Kruger National Park in South Africa, the management system works on using “thresholds of potential concern” to trigger management actions: this recognizes that systems change through time, but is responsive to the need for pre-emptive management action to prevent catastrophic shifts of the system into less desirable states.

Peatland restoration and forestry practices are recognized as forms of climate change mitigation. What other form(s) of ecological restoration do you believe can mitigate the impact of climate change and why? In our reader surveys, most readers brought up prairie/grassland restoration.

Almost any kind of restoration can have a positive impact in terms of mitigating the impact of climate change. In some parts of the world, restoration is aimed at recovering ecosystems from extreme forms of degradation and actually reinstating the ability of the human population to survive in these areas. If these projects are successful, they also provide some insurance against catastrophic climate-induced starvation, mobilization of refugees and civil unrest. In other cases, the possibility of developing economic enterprises via carbon trading may suddenly make large-scale restoration possible where it was not before. This then has the double effect of having a positive influence in terms of carbon sequestration but also providing alternative income streams for the people involved.

As your article mentions, climate change poses a potential threat to the practice of ER itself. (If people start to think, “Why, after all, support the finely honed techniques and ambitions of restoration when mere ecological productivity appears adequate?”) What do you think is the best way to address this threat?

The best answer is, I think, that restoration is part of the toolkit we need to ensure that we are prepared for an increasingly uncertain future. We need to broaden the outlook of restoration away from the simple aim of returning areas to what was there in the past. There is still room for that, especially where dedicated people and groups can invest the time and effort to look after and restore small areas. However, broader-scale restoration is increasingly necessary and this may or may not entail historical fidelity across the whole area. The mix of fidelity and functionality is something we need to think a lot about.

Can you give me an example of how one could apply the statement, “the past should serve as a guide, not a straightjacket” in an ecosystem restoration project?

As I suggested above, there is still a place for the type of restoration which aims to restore an authentic historical ecosystem in an area. However, in many cases this may be no longer possible because species no longer persist in the area or pernicious non-native species are impossible to remove completely. We therefore have to make a judgment call on whether we expend huge amounts of money and effort in trying to achieve a truly authentic ecosystem or make do with something which is similar but also different but which “works” in the world of today and tomorrow. For instance, if they find that invasive earthworms are a major factor preventing the restoration of the native woodland or prairie in the Chicago region, is it possible to contemplate doing anything about it?  Or do they simply have to accept that earthworms are now part of the system and work at restoring systems which regain some of the desired characteristics but are not the same as was there before?

Many of our readers are desperate for research and information on climate modeling. What do you think is the best source of this kind of information?

There is a lot of work going on in climate research at the moment. Probably the best place to start is the IPCC, which works to synthesize all the available knowledge. We need to remember, however, that climate modeling is still a fuzzy science, especially when we want regional-scale analyses. Hence it’s unwise to put too much store on particular predictions. A better approach is to plan for an uncertain future with increased variance (i.e. more extreme events etc) rather than for particular climate predictions.

Do you know of any studies where restored ecosystems were compared to non-restored systems to test changes in carbon absorption, heat absorption, etc?

Not offhand

We asked our readers whether they agree or disagree (in general) with this statement. Most agreed, generally. How about you?

“An important element of ecological restoration and global climate change is the restoration of ecosystems’ natural capacity to adapt to changing conditions. For an ecosystem to be able to adapt, it needs to be relatively large and healthy and connected to other relatively large and healthy patches. Smaller scale restoration may be good for education and getting people involved, but I feel that it isn’t going to be sustainable unless there are connections to larger, wilder areas.”

This goes back to our previous discussions on resilience and landscape-scale approaches. This is, I think, how we need to think about tackling the problem. However, let’s not denigrate the small-scale stuff. There’s a song by two Australian songwriters called Paul Kelly and Kev Carmody which is entitled “From little things big things grow.” Even landscape-scale responses need local implementation and without the local enthusiasm and activism we wouldn’t get very far. Also, without dedication and involvement across a broader cross section of the public, we’re not going to get the necessary changes in government attitudes and response. So it’s not one or the other, but an amalgam of both.

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