It would probably depend on your main conservation goals, for example you may have different aims depending on whether you are more interested to conserve the species in the area or to conserve the ecosystem services that it provides. In some cases, restoring a conservation area to as pristine a state as possible may be the best option. But this is often impossible as you pointed out (both owing to the typical absence of a precise knowledge of what `pristine` was in a given case before conservation interest started; and because anthropogenic impacts are now so pervasive that it may be illusory to think of pristine state being achievable). It is also good however to realise that even in pre-human colonisation times natural ecosystems have often been dynamic even over relatively short periods (e.g. de Boer et al 2013 QSR 68: 114-125). This tresses the risks of restoration aiming at any static pristine state that existed at a given point in time. In general therefore, and drawing from my experience in the tropical developing world, (where most biodiversity is concentrated and where it is typically most threatened), my view of the ideal restoration point would be that where maximum natural function is restored at the minimum cost (so as to increase chances of the restoration being sustainable). For this, it is paramount to rely on sound ecological principles to guide aims and actions.

Thank you for your replies.

So what if my main conservation goal is geared towards using ecosystem approach?

What would be the level of difficulty? I believe conservation of one species is much easier than taking the ecosystem as a whole?

Many current efforts are designed to maximize floral and faunal diversity. Start point inventories compared to regional lists provides end point goals. Habitat enrichment focusing on maintaining current inventory plus attracting new species or in the case of plants if the soil type is suitable transplanting or seeding may be possible.

The ideal restoration point is the one that can be obtained. :)

Well, yes, conserving one species is a lot 'easier' but it isn't really a 'good' idea since it would make the conserved species progressively become the dominant species in the area, which generally lessens genetic diversity. I feel it would be better to instead try conserving the ecosystem as a whole but only in an area enough to handle. For ideal restoration point, it depends but maybe when there are more young than old in the flora, I guess.

I do not believe that the pristine state (very difficult to define in most cases) is a good reference for ecosystem restoration. I believe that to define your restoration objectives you should look at what benefits the original ecosystem provided (both to humans and to the environment as a whole) and/or what problems are caused by its degradation. Another objective for restoration should be to make it resilient and/or connected to other similar patches (to reduce the possibility of future degradation and allow self-restoration). In my PhD, that deals with catatstrophic shift in arid areas, I define restoration as "reversing the consequences of degradation and blocking the mechanisms that prevent spontaneous recovery of the ecosystem".

It is a very important question in forest management and desertification projects. you could look at the results of the RE ACTION project

http://www.ist-world.org/ProjectDetails.aspx?ProjectId=254ea860483f4f21bca0db01926a62d9&SourceDatabaseId=9cd97ac2e51045e39c2ad6b86dce1ac2

It is important to take into account that in some areas, like Western Europe, a lot of the species-rich ecosystems need some kind of management to be preserved or restored (i.e. semi-natural ecosystems). This is because of the long co-evolution of the European landscapes and human activities. See for example: Halada et al., 2011 in Biodiversity and Conservation. Consequently, land abandonment and the restoration of 'a pristine state' (a state without human disturbance) often leads to a degradation of biodiversity. The mediterranean region is a good example of this process.

As regards to your second question, in conservation management, we often speak of umbrella species. These are species with high habitat requirements. The protection of umbrella species will consequently offer protection to the other species in the habitat.

"Pristine" for us in California for grassland habitats for example, is a 100% weed-free native ecosystem. It is like working on a landscape painting, and the first process you have to invent, is how do you start with a blank canvas? Then you rebuild the plant species plant-by-plant, just like a botanical archaeologist who is reconstructing a ruin, and by adding each new native species, they start working on filling in the missing puzzle pieces.

Hi Prishnee, the Society for Ecological Restoration International has a primer about using terminology in restoration ecology, e.g., when to say ecosystem restoration vs. rehabilitation. That might prove useful, especially Section 3 "Attributes of Restored Ecosystems", Section 5 "Reference Ecosystems", and Section 8 "Restoration Planning".  I agree with Matteo that the "pristine state" is a problematic reference point for restoration, but more because it would be hard to define what pristine means! Is that before industrialization, before the most recent round of human disturbance? Does the scenario change if the disturbance was natural? Does the environment you are considering have a long-term history of human manipulation, i.e., for centuries or millenia, so removing that disturbance(s) changes the ecosystem? It might prove prudent to consider multiple restoration points, along a trajectory, to buffer against uncertain future changes in the environment (a la Mori 2011 Journal of Applied Ecology).  Best of luck with the project.

http://www.ser.org/resources/resources-detail-view/ser-international-primer-on-ecological-restoration

http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2664.2010.01956.x/full

Hello Aerin, thank you so much for your answer and best wishes. Indeed, the points you made are worth considering before taking any crucial step.

Dear Prishnee Bissessur,  If you could give some more details about your project, like location, what kind of ecosystem, what conditions are you starting with, how big of an area total you want to restore, what scale of annual work do you want to do, how long would project be working, do you have nurseries or seed companies able to produce local native plants or reproduce seeds for the project, and most importantly, what is the annual economic budget per hectare--then you may be able to get some details that could help you more than general comments that can be offered.  

For example for my 70 acre (28 hectare) California grassland project at http://www.ecoseeds.com/arastradero.html, to eliminate the weeds and replant the native seedlings, it is costing $5 per plant in materials and labor.  If doing the project by plants instead of seeds, it costs about $1 million per acre at the inflated California costs, where the smallest home you can buy here costs one million dollars.  However, if I am able to do the whole project with local native seeds, that drops the price for the whole 28 hectares to maybe $3-5 million dollars.


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