The Recent Double Paradigm Shift inRestoration Ecology

Vicky M. Temperton1,2,3

Abstract

The fields of ecology and ecological restoration possess anenormous potential for cross-fertilization of ideas andinformation. Ecology could play a major role in informingpractical restoration, whereas restoration projects, oftensituated in quite extreme environments, provide an excel-lent opportunity to test ecological theories. Efforts to baserestoration on more of a scientific foundation, however,have recently started gathering momentum, following thecall for such a link by Tony Bradshaw in 1987. On anotherlevel, as we gather more experience and information fromrestoration projects, it is becoming equally clear that oftenneglected socioeconomic and political aspects of restora-

tion should not be forgotten in the overall approach torestoration. The two paradigm shifts in ecological restora-tion, toward more scientific foundation and better inclu-sion of socioeconomic limits and opportunities, locaterestoration firmly in the transdisciplinary arena, with allthe concomitant challenges and opportunities. In thissense, ecological restoration could be compared to themedical profession, where both a sound knowledge of sci-ence and human nature are a prerequisite for success inhealing.

Key words: arts, ecological restoration, paradigm shift,science.

Introduction

My experience as a professional ecologist is that the aver-age layperson assumes that I am an environmental activistwith the laudable aim of saving the environment from ourhuman impact, much like someone who works for Green-peace. We are assumed to be single handedly saving theworld. In actual fact, ecology is an interdisciplinary sci-ence, and as a science it has the aim of furthering ourknowledge of nature, and in particular about the interac-tions between living organisms and their environment.The application of this knowledge, such as an understand-ing of what drives populations or communities of organ-isms to transition from one state into another, forms partof the field of applied ecology with links to biological con-servation and ecological restoration. Ecology of coursehas an important role to play in informing more appliedand political environmental activities because these relatedirectly to the living biota and how interactions within thisbiota have feedback effects on the environment, but therole of the science of ecology is not per se to actively con-serve species or make sure the environment is notdegraded. Here is where the practice of ecological conser-vation and restoration come into play. The one strives to

preserve what is there and the other strives to restore whatwas there or to stem the loss of what was there before.

The First Paradigm Shift in Restoration Ecology:Uniting the Practical with the Theoretical

Ecologists have been arguing for well over a century aboutfundamental views of nature; whether natural systemstend to be cohesive, integrated wholes which when dis-turbed develop back to a specific deterministic endpoint(Clements 1916) or whether ecosystems are essentiallystochastic consisting only of the sum of all the parts andwhichever parts are present depends only on the luck ofthe draw (Gleason 1917, 1926; van de Maarel & Sykes1993; see Davis & Slobodkin 2004 versus Winterhalderet al. 2005 for the latest version of the debate). Morerecently many ecologists have come up with alternativeexplanations of how nature works, invoking the conceptsof alternative stable states (Sutherland 1974) and thresh-olds beyond which ecosystems can suddenly develop in anentirely new direction (Hobbs & Norton 1996, 2004; Choi2004; Suding et al. 2004). This legacy of ecological theoryis highly relevant to the practice of restoration ecologybecause it relates to one of its fundamental questions(Young et al. 2001): do disturbed communities tend torepair themselves and return to the predisturbance state,or do historical and stochastic events in a particular com-munity produce a variety of alternative stable states?

Despite some notable exceptions (e.g., the successfulexistence of the Journal of Applied Ecology since the1960s), academic ecologists and practical grassroots

1Max Planck Institute for Biogeochemistry, PO Box 10 01 64, D-07701 Jena,Germany2 Institute of Chemistry and Dynamics of the Geosphere, ICG3,Research Centre Julich, Leo-Brandt-Strasse, D-52428 Julich, Germany3Address correspondence to V. M. Temperton, email v.temperton@fz-juelich.de

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ecologists and restoration practitioners interact and shareideas surprisingly little, even though the potential for syn-ergy and cross-fertilization between these two groups isobviously large. The reason for this is partly related to cer-tain characteristics of both scientific and applied ecology.Because science purports to be objective, academic ecolo-gists have traditionally steered clear of getting involvedwith political or sociological issues related to their workbecause they fear this could detrimentally affect theirunbiased view. They have thus traditionally left the con-servation/preservation and restoration work to the morepractically and politically minded. Not surprisingly there-fore, conservation and restoration ecology have laggedbehind in knowledge and acceptance of the latest ecologi-cal theories, and conversely, more theoretical researchershave often lost out on a goldmine of practical informationthat could be fed into their theories.

The synergistic interaction between the academic andthe practical is not only a laudable aim in itself but is fastbecoming a necessity if we are to be able to adequatelydeal with the current environmental challenges faced ona global and regional scale. A number of recent books andarticles related to restoration and its relationship to ecol-ogy and society endeavor to move the field in this direc-tion (Kauffman 2004; Temperton et al. 2004; Young et al.2005; van Andel & Aronson 2006; Falk et al. 2006). Younget al. (2005) provide some useful pointers for the majorrole ecology could play in the future in informing restora-tion and conversely how restoration projects form a superbopportunity for testing ecological concepts in very differ-ent environments.

The Necessity of Linking Science with the Arts

A number of voices in the ecological restoration literaturehave expressed concern, however, that the call for a morescientific foundation of ecological restoration (Bradshaw1987) has been the main focus of the past two decades, tothe detriment of other equally crucial aspects of restoration(Holl et al. 2003; Davis & Slobodkin 2004; Higgs 2005).Higgs (2005) warns in his article entitled ‘‘The two-cultureproblem: Ecological restoration and the integration ofknowledge’’ that restoration ecology is in danger of out-competing ecological restoration, as a result of ‘‘zealousattention to scientific and technological details’’ at the costof the broader scope of ecological restoration, which alsoincludes social, economic, cultural, and political factors.

It is becoming increasingly clear as restoration projectsincrease in quantity, size, and complexity that we needexpertise and adaptive comanagement on all levels for trulysuccessful restoration (for sensu resilience thinking, seeWalker & Salt 2006). Successful restoration requires goodplanning and scientific and technical acumen, but also theparticipation of funding agencies, the local community, anda longer-term monitoring plan to establish how successfulthe restoration was, to learn from each project for future

cases. This in turn requires considerable skills in communi-cation between different stakeholders who often use theirown particular brand of jargon and are not necessarily usedto communicating with one another. From my experienceas an editor of a book, which endeavored to improve com-munication and cross-fertilization between academic ecolo-gists and restoration practitioners (Temperton et al. 2004),it is not helpful to simply advocate that the scientific aspectof restoration should have preference over all other aspectsof restoration. Instead, it is necessary to establish a basebuilding block of a new edifice for restoration as an emerg-ing truly transdisciplinary field.

At the workshop in Jena in 2004, the participantsexplored whether restoration ecology can be considereda science. At the end of many discussions, the group hadcome to the conclusion that this was not essentially themost important question to ask, given the vast scope ofecological restoration beyond only scientific practices.The group moved on to another more important question,namely, how should we approach restoration so that itschances of success are the greatest? What factors are lim-iting in restoration and how has the perception of theselimitations changed over the past two decades? The gen-eral consensus was that initially, around 10-15 years ago,abiotic limitations were considered the non plus ultra lim-iting factors to restoration success. Only after many proj-ects managed to adjust environmental conditions to levelsappropriate for the establishment of target species, didrestorationists start to consider that the biotic limitationscan hamper restoration just as much as abiotic and thatthe two factors are intricately interlinked (e.g., the neces-sity of the presence of certain organisms for the establish-ment of others, such as mycorrhizal facilitation or changesin microsite availability for plant establishment).

A similar soul-searching process occurred recently in thefield of assembly theory (searching for the driving forces orrules in the development of ecological communities;Weiher & Keddy 1999), where there has been a move awayfrom considering assembly rules as exclusively interactionsbetween living organisms, toward considering rules thatalso include abiotic, environmental conditions (Temperton &Hobbs 2004). There is mounting evidence that the abioticand the biotic are much more intricately linked than previ-ously thought (see Jones et al. 1994, 1997 for discussion ofecological engineers, and see King & Hobbs 2006). Tem-perton and Zirr (2004) found, for example, that nurse-plant effects on the successful introduction of target spe-cies into a degraded grassland changed from being essen-tially abiotic and facilitative during the regenerative phase(seed to seedling) to being biotic and competitive duringthe establishment phase (seedling to adult). The recogni-tion of the difficulty of separating the abiotic from thebiotic in certain restoration ecological scenarios has veryimportant implications for restoration ecology and ecolog-ical restoration. Without more knowledge of which limit-ing factors to restoration are solely abiotic, which solelybiotic, which intricately linked with one another, and even

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more importantly when the switch over between the twotake place, successful application of ecological knowledgein restoration will remain at a suboptimal level.

The Second Paradigm Shift in Restoration Ecology:Uniting Science with the Arts

The second paradigm shift currently occurring in ecologi-cal restoration and its academic sister restoration ecologyis the realization that the whole system we need to dealwith is more complex even than all the multifacetedaspects of applying ecology to restoration. There is anemerging sense that we as ecologists can no longer leaveall the political and socioeconomic issues of restorationand conservation to the practitioners, managers, and poli-ticians. This opens up the need for a new willingness ofecologists to discuss their potential new role in transdisci-plinary settings while at the same time ensuring that thescience of ecology does not become biased toward oneparticular political or economic slant. Equally, there isa sense that practitioners should no longer treat each res-toration project as a single isolated case study with no pos-sibilities for an informed interactive role with academicecology. We clearly need to spend more time getting toknow the other stakeholders better, in order for the mar-riage to work (see Walker & Salt 2006 for an excellentapproach). The need for people from very different disci-plines to communicate more with one another is becomingfelt in many areas of academia and public life, not least aswe are experiencing a decreasing public interest in sci-ence. Essentially, socioeconomic limitations to restorationneed just as much attention as abiotic and biotic ecologicallimitations, and the need for developing a common lan-guage is a prerequisite for the success of this endeavor.

Pointers for the Future

During the Jena workshop we discussed the idea of seeingthe practice of ecological restoration much like the prac-tice of human medicine. Restoring degraded ecosystemsback (or forward) to a desirable state works in very similarway to the practices of the medical and healing sciences. Itrequires considerable knowledge in both the arts and thesciences, including the art of combining scientific knowl-edge with the skills to treat the individual needs of thepatient, while at the same time acknowledging that everyindividual has an own specific history and is essentiallyunique. Without an awareness of the environmental andpsychosocial conditions in which the patient finds him- orherself, however, no effective healing of the patient is pos-sible. This is the same when dealing with an ecosystemthat has been degraded and the goal is to restore it toa particular state or ecosystem dynamic. The restorationpractitioner requires a sound knowledge of issues in envi-ronmental science and ecology, but he or she will not getvery far, if the other limits to restoration at that particular

site and region are not taken into account. If the localcommunity as stakeholders is not included in the processfrom the start, or funding is scarce, then these can be therestoration projects that fail despite very clear ecologicalinformation and ideas being involved. Degradation historyand local confounding factors and opportunities need tobe elucidated before restoration can be a success.

Even though the terms ‘‘health’’ and ‘‘integrity’’ are an-thropomorphic views of nature (see discussion in Lancaster2000), in a broad sense I advocate the inherent usefulnessof using these terms to address issues in conservation andrestoration because we would not even feel the need torestore or conserve if we considered all possible states ofnature (including bare substrate almost devoid of life suchas certain post-mining landscapes) as a desirable or viablestate for an ecosystem to be in (Harris & Hobbs 2001).There are broad categories that we can define related tothe desired state of a habitat (related to the diversity of spe-cies and to processes in that ecosystem). This then informswhat we think an ecosystem used to be like, what potentialit has, and where we want the system to move toward,knowing fully well that we will never know for sure whatthe exact historic ecosystem was and what the future eco-system will be like in detail. In keeping with the medicalanalogy, five different doctors could not give you a unani-mous and thoroughly foolproof definition of what consti-tutes a healthy individual, and yet we all know, even asnonmedical specialists, generally when a person is nothealthy or well and we can provide advice on how the per-son can be ‘‘restored’’ to a so-called healthy state.

Given global change and the increasing globalizationand mobility of living organisms between ecosystems andthe resultant burgeoning academic field of exotic speciesinvasions (Holmes & Richardson 1999; Sharma et al. 2005),the complexity and feedbacks in our unpredictable futureenvironment is on the increase, despite endemic biodiver-sity being on the decrease. Ecological rules that applied inthe past may not apply in the future and we may have toaccept that we cannot go back to an exact replica of thepast (Leach 2005; Hobbs et al. 2006), even if we tried.Indeed, more and more ecologists advocate the need tothink about ‘‘designer ecosystems’’ (MacMahon 1998)where we as humans play the defining role in deciding whatexists in that system, perhaps even redefining what an inva-sive species constitutes. In accordance with this, someecologists working in restoration advocate the idea of‘‘futuristic restoration’’ (Choi 2004), which acknowledgesthat the usefulness of historic ecosystems in an ever-changing and unpredictable world is of limited value andthat restoration has to keep up by taking global change intoaccount in its concepts and goals. This does not mean wedo not need to be concerned about invasive species, loss ofdiversity, habitat degradation, or global climate change butthat we need to include them when we consider how tomanage the earth’s ecosystems in the present and the future(Harris et al. 2006). The key issue is defining our aimsclearly, setting up the conditions that lead to the

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achievement of these aims and monitoring the success ofthe enterprise over long enough time frames to ensure sus-tainability (Hobbs & Harris 2001). As Young et al. (2005)point out, so far we have very few assessments of thelonger-term dynamics of restored ecosystems and theirviability. To do this effectively and successfully we need toactively foster collaborations between all the stakeholdersinvolved in the restoration of ecosystems, not just the scien-tists or the practitioners in isolation. This is the currentchallenge for both restoration ecology and ecological resto-ration. As we continue to lose species at a similar rate tothe great extinction events of the geological past, at thesame time as the human impact on the globe increases, thefuture role of a field such as restoration, which strives toincrease diversity, can only be a major one.

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