Archive for the ‘Indicators’ 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.

Ecometrica’s Normative Biodiversity Metric: is it really a good idea?

Sunday, February 12th, 2012

Ecometrica, a Scottish consultancy, just wrote up guidelines for a new biodiversity metric. The Normative Biodiversity Metric (NBM) uses an interesting shortcut between “pristine” land and biodiversity to assess the overall land-holdings of the organization being assessed.

Because the metric uses widely applicable classes of “pristiness”, it can itself be widely applied, at various spatial scales. In fact, NBM relies on existing mapped data concerning land-use and land-cover. This wide applicability is the metric’s main strength.

In trying to apply concepts and ideas developed for green house gas emissions (GHG) to biodiversity, Ecometrica has chosen to simplify the later to a single easy to use metric. Why not? That choice does however raise the issue of over-simplification. When does “pristine” actually equate biodiversity and is that particular biodiversity the most relevant one to consider in assessing an corporation’s impact?

The NBM is designed to provide an equivalent to corporate GHG assessment, for biodiversity impact.

The documentation shows that the metric can incorporate additional field information, e.g. from surveys of the species or habitats that are actually present on-site. Yet, it is clear that the metric was developed to avoid field surveys as much as possible:

the biodiversity assessment methodology cannot be wholly dependent on the use of ecological surveys carried out by experts

Is that really a good idea? As usual, it depends what you use the metric for…

Key issues in developing rapid assessment methods of ecosystem state

Friday, February 25th, 2011

David K. Rowe and his colleagues from the National Institute of Water and Atmospheric Research of New Zealand have developed a rapid method to score stream reaches. In presenting their method, the go through several of the key steps (and difficulties) in developing such “rapid assessment methods”. We summarize these below:

  • Scores are often given in reference to a desirable state (or “best of a kind”). This is helpful for ensuring that all assessors share the same upper bounds in their assessment. Selecting reference sites is however a tricky task and in particular if assessments do not focus on an ecosystem as a whole but on separate “functions”. Rowe et al. (2009) raise the issue of artificial streams performing certain functions better than reference sites. In this case they argue that this “over-performance” should be ignored: the artificial stream should be given the maximum score – that of the reference – for the particular function.
  • The selection of variables is a key step in method development. It requires an understanding of the system being assessed or of the main drivers of the system’s state (i.e. a conceptual model of the system). The conceptual models can be tested using field data. As an example, Delaware’s DERAP method was built through multiple regression analysis of independent evaluations of wetland states with set of stressor variables against (on 250 different wetlands!).
  • Developing algorithms for combining several variables into single scores is where many methods fail to convince (see for ex. McCarthy et al. 2004). Algorithms can be tested against results from established methods or best professional judgement, using field sites or consensual reference sites for example. Alternatively, statistical models can be used to weight the variables (as in the development of DERAP).
  • Redundancy is unavoidable because of the interdependence of the many processes being assessed. Moreover, redundancy contributes to robustness in the face of user/assessor subjectivity. As an example, Florida’s UMAM method relies on best professional judgement but gives detailed guidelines through a list of criteria that are very redundant. The robustness of a method to user bias can be assessed through sensitivity analysis.
  • Once a method has been proposed, it must be revised and improved through testing and feedback from widespread use.
  • The team who developed California’s rapid assessment method (CRAM) also made recommendations concerning model development (available here). They offer a more formalized step-by-step process that includes several of the points raised by Rowe and his co-authors.

    Biodiversity quality?

    Wednesday, November 3rd, 2010

    Alan Feest and his colleagues have been very productive recently in arguing for a new concept: biodiversity quality. What is that?

    Basically, considering that considering the total number of species in a given location is not enough to describe that location’s value in terms of biodiversity, they argue that decision-makers should instead use a basket of indicators that includes standard biodiversity indicators (such as the Shannon-Wiener index) but also densities, biomass and/or indices of species conservation value (built through a weighing of species based on their conservation status). Mr. Feest says so himself: this is not new!

    Calling this approach a new paradigm and labelling it “biodiversity quality” might be a bit presumptuous but the point of jointly using multiple indicators remains particularly relevant. This is because ecosystem management and nature conservation are now under heavy pressure to itemise ecosystems into “manageable” components (e.g. “biodiversity” or this or that “ecosystem service”). Multi-criteria methods such as those advocated by Mr. Feest are no doubt a useful answer, which could be used as an alternative to the bundling of the items suggested by Kosoy and Corbera (2010).

    On commodity fetishism and the itemisation of ecosystems

    Tuesday, November 2nd, 2010

    In a remarkable paper, published in 2010 in Ecological Economics*, Nicolás Kosoy and Esteve Corbera, gave an in-depth political-science look at payments for ecosystem services (PES). They suggested that their development as a solution to nature conservation’s failures amounted to “commodity fetishism” (after Karl Marx’s use of the term for describing the nascent labour relations in Capital [1867]).

    They described the process of commodification which is prevalent in PES but more generally in all the current and up-coming “markets” for biodiversity and ecosystem services, which need precise ecological “things” to trade, sell, value or offset. Accounting frameworks such as the ones we discussed in a previous post require commodification. Concerning PES, this is how they describe commodification:

    First, it involves narrowing down an ecological function to the level of an ecosystem service, hence separating the latter from the whole ecosystem. Second, it assigns a single exchange-value to this service and, third, it links ‘providers’ and ‘consumers’ of these services in market or market-like exchanges.

    Commodification leads to complex ecosystems being compartmentalised into discrete elements or items. Ecological sciences are increasingly called upon to identify, quantify and map these “items”, and hence ignore the complex interactions between and among ecosystems (which they strive to untangle!). Because tradable items must be reliably (and cheaply) measured or counted, proxys are usually needed which further reduces the ecological complexity or realism they encompass.

    Kosoy and Corbera suggest that ecosystem services be bundled up to favour the provision of multiple ecosystem services rather than aiming for the maximum production of a unique target service. This requires additional knowledge about the interactions between ecosystem services and the synergies and trade-offs between services. These lines of research are in their infancy, and remain limited by the many gaps in our understanding of real-world ecosystem dynamics, concerning the effects of management interventions or those of external drivers such as climate change. Exchanging scientific accuracy for simplification will not help in this endeavour!

    A more general solution to the issue of itemisation that bundling services would be to set safeguards on ecosystem management, whereby market-based mechanisms would be allowed to operate within certain ecological limits that guarantee a site’s “evolutionary” and “ecological” potential. This requires mixing marked-based mechanisms with standard (command-and-control) mechanisms. Would that be an on-the-ground translation of the pluralism that Kosoy and Corbera call for?

    * Kosoy, N. & Corbera E. (2010): Payments for ecosystem services as commodity fetishism. Ecological Economics 69: 1228-1236.

    13 important isssues for developing practical conservation goals

    Monday, March 1st, 2010

    In a review published in 2008 in Ecology Letters, David Lindenmayer and a long list of co-authors discuss some of the most important concepts used in describing, understanding and managing biodiversity and ecological processes at the landscape scale. These include classifying landscapes into habitats, describing and assessing their internal structure and condition, describing their disposition in space and time as well as their connections and hedge-effects.

    Their review of these concepts is relatively broad but difficult to follow. It does not offer a very satisfying conclusion, except a worthwhile attempt to synthesize how these concepts relate to each other in a box-and-arrow diagram.

    The more interesting part of their review is their suggestion of 13 important issues to be considered in developing practical goals for conservation. These are the following:

  • Develop long-term shared visions and quantifiable objectives
  • Manage the entire mosaic, not just the pieces
  • Consider both the amount and configuration of habitat and particular land cover types
  • Identify disproportionately important species, processes and landscape elements
  • Integrate aquatic and terrestrial environments
  • Use landscape classification and conceptual models appropriate to objectives
  • Maintain the capability of landscapes to recover from disturbances
  • Manage for change
  • Time lags between events and consequences are inevitable
  • Manage in a experimental framework
  • Manage both species and ecosystems
  • Manage at multiple scales
  • Allow for contingency
  • Each one of these issues is discussed in the paper and although they might seem trivial to some, lack of time or expertise often means they are not appropriately accounted for in the design of conservation policies. This situation makes the paper a useful reminder! The authors conclude by listing some key research topics including the challenge of making the enormous mass of ecological knowledge relevant to on-the-ground management of ecosystems and biodiversity. That’s a hard one!

    Is there a place for a binding “duty of care” for biodiversity conservation?

    Thursday, February 18th, 2010

    A recent article by G. Earl, A. Curtis and C. Allan in the journal Environmental Management discusses the feasibility of imposing a duty of care for biodiversity to land owners and land managers. They explore the specific case of Australia but many of their ideas resonate with the broader issue of developing an appropriate policy mix for conserving biodiversity outside protected areas. The authors argue that as an established legal principle, “duty of care” (rather than the looser moral obligation of “stewardship”) can relatively easily be applied to biodiversity. A government report published in 2001 also addressed this issue and the authors make an important contribution in proposing guidelines for actually implementing a duty of care policy.

    Picture of a Eucalyptus woodland by ButterflyHunter (http://www.flickr.com/photos/7719574@N06/1375259579/)

    One of the key points discussed in the article is that of setting clear goals for biodiversity: “desired outcomes” that must be set at the catchment or landscape level (or whichever administrative or management unit is appropriate). Establishing such goals would be a requirement for a duty of care policy but would of course be very useful to a whole suite of existing policies (including those based on the evaluation of impacts on biodiversity).

    The authors also argue that this desired outcome should probably be based on the maintenance of the ecosystem or landscape level processes that underpin biodiversity (as well as ecosystem services that are important to humans). However, they recognise that many of these are little known or hard to measure and that appropriate indicators might often rest in identifiable biodiversity components (species presence or abundance, habitat acreage…).

    The framework conforms with much of the current dialogue concerning biodiversity conservation across landscapes, in seeking to articulate quantifiable and ‘‘biophysically meaningful’’ desired outcomes for biodiversity that incorporate measures of size, configuration and connectivity of habitats, as well as vegetation condition measures that collectively act as surrogates for ecological processes.

    This dialogue is very much at the centre of any policy aimed at stopping biodiversity loss or improving its status, be it stewardship, duty of care, offset schemes or top-down command-and-control rules and regulations.

    Biodiversity indicators: 10 common mistakes

    Wednesday, October 28th, 2009

    In a paper published in 2003 in the Journal of Environmental Management, Lee Failing and Robin Gregory list 10 common mistakes made in designing biodiversity indicators for forest management. The paper is a worthy read for anyone dealing with issues of monitoring or decisions concerning land-use or ecosystem management.

    According to the authors, indicators can have three uses: tracking performance (for results-based management), discriminating alternative hypotheses (for scientific exploration), discriminating alternative policies or management options.

    In their paper, they focus on the latter. They list ten common mistakes made in developing and using biodiversity indicators aimed at providing guidance to policy makers or forest managers who must decide on landscape or forest management policies and plans. Deciding whether or not to allow a specific project to go forward requires a different suite of indicators than assessing whether or not the project was a success.

    They provide a nice example to illustrate their point:

    When we go to the doctors and ask “what is my risk of heart disease”, we do not expect the answer to be framed as a percentage of the target daily donut intake”. (…) Eating fewer donuts may be part of a sensible management strategy but it does not answer the question “am I healthy?” A report of two dozen indicators may be an important part of the the analysis process, but it is also not an acceptable answer to the question (…). Doctors it seems understand the need to take a complex thing, break it down into a relatively small number of indicators, and provide a summary judgement about the status of our health or the probability of recovery associated with alternative treatments.

    The 10 mistakes:

  • 1. Failing to define end-points – Is the aim to preserve ecosystem services or scenic value, to prevent the loss of a particular set of species or the intrinsic values and rights of all species.
  • 2. Mixing means and ends – Appropriate performance indicators should focus on the desired goals, not on whether “actions” were taken. Guideline are no substitute to goals.
  • 3. Ignoring the management context – Outside a specific context, “biodiversity” has no meaning – The context must thus be specified.
  • 4. Making lists instead of indicators
  • 5. Avoiding importance weights for individual indicators – Unfortunately, stating that “everything is important” doesn’t work in practice.
  • 6. Avoiding summary indicators or indices because they are considered overly simple
  • 7. Failing to link indicators to decisions
  • 8. Confusing value judgements with technical judgements
  • 9. Substituting data collection for critical thinking – If no data is available, then the authors suggest using established methods for gathering and synthesizing qualitative expert judgements.
  • 10. Oversimplifying: Ignoring spatial and temporal trade-offs – In giving examples for mistake 10, Failing and Gregory mention the importance of taking into account spatial and temporal trade-offs in designing policies aimed at no-net-loss of biodiversity. Temporary and /or local losses could provide – or be made to – provide gains at a broader scale or on the longer term. The same point is made by Kerry ten Kate in an EM podcast on making biodiversity offsets work (mp3).