It’s easy to argue that history has a bigger influence on why we restore ecosystems than on how we restore them. As climate change intensifies, that distinction can only grow.
Information from the past underpins ecological restoration. In fact, many people argue that history is essential to restoration. “To ignore the legacy of an ecosystem,” writes Eric Higgs, “even in cases where specific historical information is scanty, is to practice something other than restoration.”
But as climate change intensifies – causing species to move and ecosystems to change – the philosophy and the practice of restoration will also change. Will historical information still be relevant? In the future, how will restorationists think about the past?
To answer these questions, we have to look in the mirror. We have to ask ourselves: “how on earth do we use historical information to guide restoration?” Right here, right now. And if we discover that we use historical information in lots of different ways, we can then look forward and ask: “which of these approaches will remain relevant, and which will fade away, as global change progresses?”
The long mirror
Eric Higgs – the environmental philosopher quoted above – must spend way too much time looking in the mirror. He recently co-wrote a fascinating paper on the many ways that we use historical information when we restore ecosystems, and on how these approaches may alter as global change intensifies.
Higgs and colleagues thought of not one, not two, but nine, different ways that historical records inform restoration. They argued that – no matter how far species move or ecosystems change – history will always be important to us, because it influences why we save ecosystems. Ecologists and restorationists rarely talk about that stuff. We focus on numbers and facts, on how history can inform what we restore and how we restore it, not why we bother.
Higgs and co describe their paper as an “initial step” to stimulate “ongoing debate and refinement” of the topic. In that spirit, I have re-organized their framework and changed their categories in the essay below, so it works well for me. I encourage everyone to read their paper, and to contemplate how you use information from the past when you save and restore ecosystems. As we reshape our views of the past, we co-create restoration for the future.
The most obvious way we use historical records is to copy them. Old paintings and pictures provide a stencil or template that guides restoration projects. We can mimic the historical structure of an ecosystem – the height, density and spacing of trees – and its composition.
In reality, this plant-by-numbers approach is a crude caricature. Old pictures are rarely that accurate, our tools are rarely that good. The process is usually more abstract, less literal. We compile a vision from fragmentary sources: pictures, texts, maps and lists. We work towards something that resembles a stretch goal more than a stencil; a goal we strive towards but may never attain – even as we continue to make substantive improvements.
The guide book
Should you ever visit the Sistine Chapel, it helps to have a guide book. Even with one, it’s a glorious, bewildering spectacle. Who the hell is that guy? Why is everyone naked? What on earth – or is that heaven or hell – is going on?
To restore an ecosystem, we need to know the context, the ecology, the story behind the scenery. A stencil alone is not enough, we also need a guide book to show us how the system works. Historical records help us to understand the processes that shape ecosystems: the impact of Indigenous peoples; the legacies of fires, floods and grazing animals; the effects of soils and nutrients. These records give us clues about how disturbances may affect our works. They invoke constraints: we cannot hope to restore a wetland with too little or too much water.
History as process
You may choose to restore things in a completely different way; to reinstate indigenous fire regimes, re-introduce top-level carnivores, or replenish environmental flows in degraded rivers. These goals all share a common feature. They aim to restore historic processes, disturbances and interactions instead of an historic structure or composition.
When we do this we cross our fingers and hope that the reinstated processes will deliver something we like. They don’t always. Many processes cannot be reversed. Many outcomes are unwanted, including invasive exotic species. Nonetheless, when we re-align processes towards their ‘historical range of variation’ we acknowledge the dynamism of ecosystems, and the importance of disturbances and interactions. We can (and should) learn these things anew through trial, error and experiments. But history broadens our horizons and can expand our choice of treatments.
The historical ledger
History provides a book of accounts, a ledger, with which we can assess changes and set priorities. The simplest measure of change is a decline in distribution or abundance: “the Golden Ephemera was eliminated from 97% of its range”; “Turquoise Lipustras occurred in their millions, now fewer than 800 survive”; “less than 1% of native grasslands persist in high quality remnants.” This way of using historical records is fundamentally different from a template or guide book. A template shows us what to restore. A guide book suggests how to restore it. The ledger tells us which things to restore and which to ignore.
The accidental laboratory
And yet there’s more to see in Eric’s long mirror. Historical information helps us to interpret a natural laboratory of accidental experiments. We can work out how grazing affects grassland plants, for example, by observing the presence of rare plants in ungrazed remnants. These accidental experiments, and the hypotheses we draw from them, fast-track our knowledge of how ecosystems work. Looking forward, we integrate all these forms of information with other sources of knowledge as we create models and scenarios to appraise changes in the future. All our scenarios, all our predictions extrapolate from history. A little more, nothing less.
A toss of the coin
Old historians don’t predict, they know the unexpected is lurking. Unpredictability, contingency, uncertainty, stochasticity, the butterfly effect, alternative stable states, black swans, novel ecosystems, chance and luck; we discover all of these in the glitches of history. History is the coin toss in our models of the future. We cannot look forward without it.
Behind the facts
Restorationists and ecologists are comfortable using historical information in these ways. Information from the past lets us measure things, count things, add them up and divide them. Looked at this way, history is just a shitty dataset. But number-crunching ignores something bigger. Before you or I chose to restore anything, we were each inspired to restore or save something. Most of us realized this long ago. We grew up, took our inspiration for granted, and now wonder why the rest of the world just doesn’t get it. We need to remember why we care.
Somewhere, deep in academia, there’s an unwritten law that says – should you ever write a popular article about Australian mammals, you must begin by reminding your readers of one inexcusable fact: “Australia leads the world in mammal extinctions.” Lack of imagination aside, this sentence is repeated ad infinitum for one simple reason; we don’t want it to happen again. Information from the past inspires us to save and restore species and ecosystems. (Regardless of whether or not we choose to restore ‘historical ecosystems’). Without history, conservation and restoration have no more future than the 22 species of extinct Australian mammals.
Redress and atonement
My grandparents worked hard to clear this land. The government told them to. They thought they were doing good. Now we know they made mistakes. We’re restoring the land to make it healthy again, to fix the problems they made.
Many of us – should that be ‘all of us’? – save and restore ecosystems for a bigger reason than breeding bilbies, poisoning weeds or boosting small populations. We restore as an act of atonement for past and present wrongs. Doubt me? How often have you read a quote like that above?
Atonement need not be rational. It doesn’t appear in any spreadsheet, threatened species policy or ecology paper. It preceded the algorithm, the policy and the science. It is the reason why we work, although we often forget that. We scientists and practitioners need artists to remind us that a field of plantings is more than a row of trees. Restoration is an act of redress and atonement. An action inspired by stories from our past.
Our place and community
When you finish this article, type tree planting in a Google Image search. You shall find thousands of photos of happy, smiling people, all digging holes and planting trees in the sun. It never rains on Google planting days. Every sunny photo sends a message: we restore ecosystems to enrich our communities and to engage with nature. Our sense of place and our sense of community are both drawn from our history. Before we can lament the Last Child in the Woods, we must first recall that there were more woods, and more children playing within them.
Choose your future
History informs restoration in so many ways. As climate change intensifies, causing species to move and ecosystems to change, which of these ways will blossom and which will fade away? Perhaps we will use history as a template less often. But will we still use the past as a guidebook and laboratory? Will one-in-100-year floods persist in our computer models and conservation scenarios? As the world morphs, will we join the mammal ecologists and wave history’s moral flag to inspire others to give a damn? Will we share stories to bind a sense of place in our restless population? As the climate distorts, will atonement be the first or last emotion to wither in the heat?
[Historical] narratives remain our chief moral compass in the world. Because we use them to motivate and explain our actions, the stories we tell change the way we act in the world.
I’d wager that there is a big future for the past in ecological restoration. How will you choose to use it?
Cronon W (1992). A place for stories: nature, history, and narrative. The Journal of American History 78, 1347-1376. [Full text article]. I love this old paper. Curl up for an evening and enjoy it.
Higgs E, Falk DA, Guerrini A, Hall M, Harris J, Hobbs RJ, Jackson ST, Rhemtulla JM & Throop W (2014). The changing role of history in restoration ecology. Frontiers in Ecology and the Environment 12, 499-506. [Full text article]