This is a follow-up of the previous post, ”How SMART is Target 2 of the EU Biodiversity Strategy?”. As you may recall, the target is to restore 15% of degraded ecosystems. But, just how measurable is this objective?
‘M’ is indeed the tricky bit in the SMART neologism*, which stands for Measurable. It is tricky, because unlike CO2 emissions, biodiversity cannot be measured by a single unit. It is also said that biodiversity is multifaceted, so we are not sure what exactly to measure.
In my opinion there are two aspects to measurement: quantity and quality. Others may want to add time, cost and even political will, but that’s another story.
Quantity is perhaps easier to handle as area or volume occupied by an ecosystem or by kg of biomass produced or elements cycled through it. And logically it seems the preferred approach when it comes to targets: area of degraded vs. restored habitat/ecosystem.
The EU has agreed to adopt restoration objectives per ecosystem type, per each major land use class and by geographical location. Member states are advised to follow a differentiated approach – to start from mapping all ‘restorable’ ecosystems (those that are not in top condition), presuming that all ecosystems conditions can be improved.
Mapping, as the MAES project in the EU states, is especially useful for the quantification of ecosystems, ecosystem services and biodiversity that are spatially explicit. EU Member States should be equipped to produce and supply the required maps by the end of 2014 (!) and through effective spatial planning systems (!!) to start using them (!!!) in protecting, restoring and re-connecting ecosystems.
Quality, poses slightly different challenges, some of which are on conceptual level, others are practical. Let’s focus on the practical and and stick to the KISS principle. What measurable traits of an ecosystem speak best about its quality?
Some say species diversity and especially indicator species can be a good proxy. A nice example is offered by a recent study on butterfly communities in a cement quarry in Tanzania (Ngongolo & Mtoka, 2013) that demonstrates the positive effect of re-vegetation with diverse but native species of trees and shrub on butterflies in comparison between re-vegetated quarry and areas of the quarry that are not yet mined. Butterflies, like birds, are a good indicator and a pleasant sight at a restored site: great for communication!
But species diversity is not always suitable measure, and we have limited knowledge on so many groups.
So the pragmatic approach for the EU member seems to be two-fold:
- Mapping of the area taken by ecosystems, qualified by their state.
- Using qualitative studies to characterise their state through locally specific descriptors.
On our next post, we will discuss letter ‘A’ of the SMART series: how Achievable is Target 2 of the EU Biodiversity Strategy?
*If you are more interested in the use of neologisms such as SMART, I’d recommend reading THIS.