Archive for the ‘Ecological restoration’ Category

Focus on the process! That’s what restoring ecosystems means, and needs.

Friday, August 31st, 2012

In 2011, Australian ecologists David J. Tongway and John A. Ludwig, published a grand summary of their multiple years of on-the-ground experience of restoring disturbed landscapes and ecosystems. Using examples from restoration works on mine sites, road verges, rangelands, and farmland they illustrate how their function-based approach plays out.

The book, “restoring disturbed landscapes – putting principles into practice“, published by Island Press, is a very accessible introduction to the Ecosystem Function Analysis method developed by CSIRO.

One of their main ideas is that restoring degraded ecosystems first requires that the problematic physical (abiotic) processes be solved: the negative effects of topography on water and material flows must be mitigated before self-sustaining biological processes can play their part (e.g. vegetation, grazing regimes, etc.).

First, solve the underlying physical processes! No point in planting your favourite flower here…

Of course, they also remind us that restoration must be framed and carried out in an adaptive management feedback loop where the ecosystem or landscape’s trajectory is monitored and compared to reference conditions. The book is a nicely illustrated reminder of these good practices…

In the context of mitigation requirements for development impacts on biodiversity, the following quote summarizes nicely one of their main points:

switching from simply observing the presence, absence, or abundance of organisms to assessing the status of functional processes in an explicitly spatial (landscape) context is as challenging as venturing into previously uncharted waters. (…) Being able to “read the landscape” is a rare and valuable asset.

Intelligent tinkering : a personal account of the science and practice of ecological restoration

Thursday, August 9th, 2012

You’re interested in the real world application of the knowledge and methods of ecological science, and especially restoration ecology? Maybe you’re interested in how the practice of ecological restoration can inform ecological theory? Whichever way, Robert J. Cabin has some interesting stories to tell on the complex and often awkward relationships between the practice of ecological restoration and the science of restoration ecology.

He tells his stories in Intelligent Tinkering, a book published by Island Press in 2011. The book starts off with a personal account of how, as an aspiring research ecologist, R.J. Cabin got drawn to the hands-in-the-mud nitty-gritty business of getting restoration plans off the ground, or rather, in the ground. He participated in planing countless native trees and shrubs in order to restore tropical dry forests in Hawaii.

Restoring these forests involved working with many different stakeholders, who often had diverging agendas. It also involved project management and hard physical labour. There was some science in there too, but it’s role didn’t follow the standard model of knowledge feeding into action… Trained as a research ecologist, maybe this model is what R.J. Cabin had initially expected to encounter when coming to Hawaii to work on restoration. The real world is just a lot more messy.

His account of how he confronted this is very interesting, and you get to learn a lot about the island’s ecology, and politics. Good writing makes it easy to follow. In a second part of the book, he tries to outline a few things he learned from that experience. This attempt to theorize the links between science and practice comes a bit short however, both in style (especially given the quality of the first part of the book), and in content.

Many authors have explored how science and practice interact but no grand theory has emerged. As R.J. Cabin explains, maybe that’s because no final, widely shared, definition has been given to either… Anyway, the key message from the book is probably that, in the end, getting things done is what matters.

Long-term floodplain meadows cannot realistically be recreated!

Friday, October 28th, 2011

Biodiversity offsets are making headlines as a new instrument or tool for biodiversity conservation in the UK. DEFRA defines offsets as actions in favour of biodiversity that are carried-out in compensation for planned impacts (e.g. from development) and provide a measurable outcome. Whenever possible, offsets should target the same biodiversity components (species, habitat types etc.) as those that will be impacted. This raises the question of their “restorability”.

In a recent paper published in the Journal of Applied Ecology, Ben Woodcock, Alison McDonald and Richard Pywell of CEH investigate the restorability of long-term floodplain meadows on agricultural land in South-Eastern England. Using an 22 years old restoration experiment, they show that given the current restoration trajectory, it would take over 150 years for the former arable land to have a species composition close to that of long-term floodplain grasslands. Even when being less restrictive in terms of restoration goals, i.e. focusing on the “types” of species (described using their morphological and reproductive characteristics or “traits”), it would take over 70 years. This is slightly more realistic but still a very long term prospect.

Ecosystems or habitat types for which restoration is a (very) long-term endeavour might fall outside the scope of offset schemes. As the authors say:

any compensation scheme proclaiming they can replace floodplain meadows lost to development (i.e. gravel extraction) is being wholly unrealistic.

As well as actually avoiding the destruction of hard or impossible to replace ecosystems and habitat types, these findings raise two issues:

  • can the destruction of these habitats be offset by restoring or enhancing degraded habitats (of the same type). This amounts to exchanging area (for which there will be a net loss) by quality (for which there would be no net loss). Is this acceptable? Another option considered by DEFRA is to use out-of-kind offsets.
  • how can the delays associated with restoration or enhancement of habitat types be taken into account in the design and sizing of biodiversity offsets. DEFRA proposes to use “multipliers” for this but these will probably be very hard to justify, ecologically, as ensuring that offsets lead to no-net-loss of the particular target habitat type.
  • Hopefully, the pilot scheme launched by the UK government will give the opportunity to test these solutions…

    Biodiversity: the new carbon?

    Tuesday, February 8th, 2011

    The Guardian, a leading UK newspaper, recently published an interesting analysis of biodiversity as the new “carbon”. After discussing how biodiversity has emerged as a new issue for companies to incorporate in their business strategies, the article details the main motivations for this.

    The first motivation mentioned is reputational risk but the most interesting is the one concerning a company’s liability in case of impacts or damages on biodiversity. The Deepwater Horizon oil spill (BP) is used as an example. This underlies two things:

  • That the “business case” for incorporating biodiversity in business decisions and strategies is strongly dependant on an appropriate institutional context where companies are liable for impacts on biodiversity. The requirement to avoid, reduce and offset impacts is one such context.
  • That anticipating possible impacts and the potential financial losses that could result from such impacts requires the development of impact assessment procedures and methods that can be parametrized in advance.
  • The USA have developed assessment methods to be applied in the context of Natural Resource Damage Assessment procedures (NRDA), such as Habitat Equivalency Analysis and Resource Equivalency Analysis. In Europe, the 2004 Environmental Liability Directive will certainly make governments and environmental authorities push for the development of such methods.

    Towards no net loss, and beyond (in the UK)

    Friday, December 31st, 2010

    I had mentioned in a previous post how the UK was discussing policies for biodiversity offsets and habitat banking.

    Conclusions from the Natural Capital Initiative‘s third workshop, which took place in early December 2010, are not yet on-line but they are discussed by Daniel Kandy of the ecosystem market place on their website.

    He argues that the workshop gave little hope for a national policy framework or strong government regulations on offsetting. A framework for voluntary offsets by developers is a more likely outcome of the current discussions, in particular under the new coalition government:

    Given the coalition government’s commitment to reducing regulation and meting out more power to local governments, a biodiversity offset program will more than likely be voluntary in nature and be regulated at the local level. After years of a Labour government opting for top-down regulatory approaches, the Conservative-Liberal Democrat coalition government has decided to move towards a less centralized form of government oversight.

    The government will state its position in the spring of 2011, in a white paper called the “Natural Environment Policy Paper”. Meanwhile, discussions continue. Stay tuned for the publication of the workshop’s conclusions by the Natural Capital Initiative themselves…

    The Tolstoy effect

    Sunday, December 12th, 2010

    In Anna Karenina, Tolstoy reminds us that “happy families are all alike” while “every unhappy family is unhappy in its own way”.

    Emilie Stander and Joan Ehrenfeld concluded that the same was true for wetlands. They studied the functioning of wetlands used as (supposedly “pristine”) reference wetlands for wetland mitigation in New Jersey (USA) and found that in this heavily urbanized setting, even reference wetlands were “unhappy”… (pdf here)

    This raises issues for using typologies of wetlands in the assessment of wetland states (as in the context of wetland mitigation in the USA).

    Identifying reference wetlands on the basis of standard structural indicators is misleading when wetlands are in heavily modified landscapes and watersheds. They suggest that instead, multi-year data on functioning should be used to create appropriate typologies of wetland functioning.

    A further step would be to use “theoretical” references for assessing wetland state but this would most likely make in-the-field assessment more difficult.

    Setting restoration targets : how specific should they be?

    Tuesday, December 7th, 2010

    In a recent paper published in the journal Wetlands, Diane De Steven and her colleagues present a 5 year restoration experiment where they tried to pilot restored coastal depressional wetlands in South Carolina to either herbaceous wetlands or wet forests. They failed!

    Well, they didn’t fail overall. In fact, they generate a whole suite of restored wetlands that are well within the range of preserved wetlands in the region in terms of hydrology and plant communities. What they failed to do was to correctly predict which one of the 16 wetlands they restored would (likely) evolve into either a herbaceous wetland or a wet forest. This is because they could not predict the restored hydrology of each wetland (restored by plugging drains) which is the main determinant of tree establishment, ahead of planting tree seedlings into the wetlands targeted to become wet forests.

    Diane De Steven and her colleagues draw several conclusions from this outcome :

  • There are high stakes in evaluating ecological restoration success in wetlands because of the requirements for mitigating wetland losses
  • Restoration success is rarely a simple yes / no outcome
  • Specifying, in advance, a specific plant community as a target for restoration ignores the variability of ecological (and community) dynamics and under-appreciates the multiple possible states of natural wetlands
  • More flexible restoration targets, based on a spectrum of reference communities (“natural” or otherwise) is more fitting to an adaptative management approach to restoration.
  • The spectrum could be defined in terms of wetland functioning, plant communities or even functional groups or functional traits (thereby recognizing that different plant assemblages can provide similar functions).
  • These are interesting ideas to keep in mind when discussing restoration (of course!) but also in designing assessment methods for wetland mitigation : with which metrics and against which targets should losses and gains in wetland condition be assessed?

    Biodiversity offsets as landscape management policies

    Saturday, November 27th, 2010

    As Barbara Bedford already stated, in her 1996 paper on wetland mitigation in the USA, that as the number of exchanges of one ecosystem for another increases, offsets change from a regulatory action aimed at achieving no-net-loss to a landscape management policy.

    This implies strategic thinking that goes beyond project per project assessments of like-for-like replacement of lost habitats and functions. Cumulative effects must be taken into account in allowing and offsetting impacts and both zoning (= planning) and nature conservation laws must therefore accommodate future projects and future offsets.

    This is made easier by the fact that the growing focus on nature conservation outside protected areas has pushed nature conservation objectives deeper into zoning laws (e.g. Natura 2000 in Europe).

    Habitat banking policies are particularly adapted to this requirement, in that they can be established before impacts as part of zoning plans. In Europe, the German Eingriffsregelung policy is a good example of this where municipalities must plan areas for offsetting future urban development included in their zoning and urban planning.

    In France, the recent launch of zoning requirements concerning ecological connectivities (known as Trames Verte et Bleue) has raised the question of using offset actions to enhance or restore ecological connectivities. This can be interpreted either as:

  • using offset requirements to compensate for the State’s incapacity to meet its legal obligations regarding nature conservation
  • a useful coordination of publicly and privately funded actions in favour of biodiversity
  • You might find the first interpretation scandalous or be proud of the second but what would the wildlife say?

    Restoration fundamentals

    Thursday, October 28th, 2010

    The following is a modified version of discussions on the ECOLOG-L discussion list (with contributions by Wayne Tyson and Eric Branton). It summarizes the fundamentals of a successful restoration programme.

    Design and implement the required restoration actions
    Step 1: Assess current ecosystem condition (structure and processes)
    Step 2: Describe and agree on desired future/restored ecosystem condition.
    Step 3: Define and agree on actions needed to reach desired condition (taking into account feasibility, reliability and costs of the proposed actions).
    Step 4: Take bold but safe-to-fail actions (i.e. taking a “what-if” approach).

    Put adaptive management in place
    Step 5: Monitor and evaluate results from desired ecosystem condition perspective.
    Step 6: Modify actions and/or expectations in light of results.
    Step 7: Continue with revised actions and monitoring.

    Note that conditions to be evaluated should include processes (population fluctuations, properly functioning soil microbial communities, forest succession) as well as the components (species present, habitat types and proportions). This prevents a project site from being considered “restored” the second the last native grass has been planted.

    Defining desired ecosystem condition may be the most challenging step: Do we want a pristine, zero human disturbance condition? E.g., a mature mixed conifer-deciduous woodland cycled with infrequent wildfires and no management of invasive species. Do we want a slightly human-controlled condition? E.g., a mature mixed conifer-deciduous woodland preserved through fire prevention and some management of invasives. Do we want a slightly more human-managed condition? E.g., oak savannahs maintained by periodic controlled burns, conifer removals and intensive invasive species removals.