Biodiversity is threatened across the globe, and one of the main drivers of that trend is the conversion of natural habitats into altered landscapes designed to be more suitable for human uses. Aside from urbanization, there’s agriculture, mining, logging, and livestock grazing to consider, for a start. While in some places it makes sense to attempt to minimize or even to reverse the conversion of lands for those activities, in other places it is more reasonable to engage with stakeholders and, in a sense, make the best of a new normal.

Take farms. Farmland is not ideal for most forms of wildlife, but in some sense, farms can be better for at least some animals than concrete jungle might be. The problem is that despite the global acknowledgement of issues surrounding biodiversity and financial commitment in many cases to conservation efforts, basic monitoring efforts are lacking. And without monitoring, it is impossible to know just what is changing, how fast, and whether those changes are net positive or net negative.

In the European Union (EU), there is some political support for linking agriculture with biodiversity conservation in productive, positive ways. By one estimate, some 30% of the EU Common Agricultural Policy (CAP) is earmarked for environment-related projects. That’s around 122 billion euros to be spent between 2014 and 2020.

But Aix-Marseille University researcher Stefano Targetti and his colleagues, writing recently in the Journal of Environmental Management, lament that none of that is specifically designated for biodiversity monitoring. “Budget constraints are considered one of the major current limitations to biodiversity monitoring activities,” they say, but offer that the solution is to raise awareness of the importance of monitoring biodiversity with stakeholders. Further, they say that providing a way for farmers to actively participate in monitoring themselves would also allow for cost-cutting.

By working with farmers, the researchers were able to identify which metrics would be most useful. Which biodiversity indicators provided the most value for the money? All indicators are scientifically useful; the question is which ones are also useful to the stakeholders.

Highest ranked was information related to plant species and habitat types on farms: for example, how much of a farm contains trees versus shrubs, what is the crop diversity on a given farm, what is the average size of habitat patches on a farm, and so on. In addition, stakeholders also ranked farm management information highly as well. Those are metrics related to grazing intensity, pesticide use, crop origin, and so on.

Next highest ranked was information regarding diversity of bee, earthworm, and spider species, since all three groups of invertebrates provide farmers with important ecosystem services.

Combined, the above information forms what the researchers call a “minimum set of indicators which provides non-redundant information and which can make dominant changes in farmland biodiversity visible.”

Armed with that information, conservation practitioners can begin to explore ways to implement monitoring for those variables on a continent-wide scale. And that’s exactly what they did.

In a second, related research effort published recently in the Journal of Applied Ecology, Aix-Marseille University ecologist Ilse R. Geijzendorffer and her colleagues ask just how much money it would take to undertake the sort of farmland biodiversity monitoring that Targetti’s team described.

To achieve their goal – likely the first attempt to provide cost estimates for empirically driven, large-scale European biodiversity monitoring – the researchers relied on a set of mathematical models.

They began with information from 12 case studies conducted across Europe on species richness for four taxa (vascular plants, earthworms, spiders, and bees) across all the major farm types (field crops and horticulture; grazing livestock; mixed crops and livestock; and permanent crops), as well as information on the spatial distribution of those farm types across the continent. Together, that information would provide an estimate for the number and distribution of farms that would need to be sampled in order to detect landscape-level changes in biodiversity. They ran their cost analysis against nine slightly different monitoring scenarios, each designed to more efficiently identify changes in the richness of a given species or taxon. The general goal was to be able to spot a 10% change in species richness over a period of five years.

The associated costs could then be compared to the CAP budget to see whether it was affordable and which monitoring scenarios provided the most information for the expense.

They discovered that monitoring for bees requires the highest number of farms to be sampled, making it the most costly monitoring effort. Cheapest is to sample vascular plants, because it would require the lowest number of farms to be sampled. Still, even the most pricey monitoring plan amounts to just 0.74% of the total CAP budget and 2.48% of the portion allocated to environmental purposes. At most, 184,000 farms would need to be sampled to achieve the most robust indicator set, while just 5,600 farms would suffice for the sparsest dataset that still remained useful.

The researchers take care to warn that their proposed monitoring scheme is not necessarily the best of all possibilities. Instead, they offer it as a “starting point for further refinement and planning purposes at European, national, or regional scale.” Still, to allocate less than one percent of the EU’s agricultural policy budget to biodiversity monitoring seems like an obvious, and increasingly necessary, move. – Jason G. Goldman | 11 November 2015

Sources:

Targetti, S., Herzog, F., Geijzendorffer, I. R., Pointereau, P., & Viaggi, D. (2016). Relating costs to the user value of farmland biodiversity measurements. Journal of Environmental Management, 165, 286-297. DOI: 10.1016/j.jenvman.2015.08.044.

Geijzendorffer, I. R., Targetti, S., Schneider, M. K., Brus, D. J., Jeanneret, P., Balázs, K., … & Kovács-Hostyánszki, A. (2015). How much would it cost to monitor farmland biodiversity in Europe? Journal of Applied Ecology. DOI: 10.1111/1365-2664.12552.

Header image: A farm in the Netherlands, via shutterstock.com

