Practitioners and policymakers must learn to differentiate between ecosystems services and biodiversity, argues Jonathan Baker
The concept of ecosystems services has, in a short space of time, come from being the topic of a few academic papers to dominating discussion about the natural environment, as well as UK, EU and international environment policy.
Ecosystems services are the benefits that individuals and society receive from the natural environment. Such services are the product of ecological and natural processes and include the provision of food (so-called provisioning services); natural areas to enjoy (cultural services); flood abatement (regulating services); and soil formation (supporting services).
To date, much of the ecosystems services debate has centred on attempts to assign a financial value to the environment based on the services it provides. Initially, this idea was perceived by some as reductionist and money-driven, but it is now seen as useful in making the case for protecting or enhancing the environment.
This has been clearly demonstrated by the UK’s natural environment white paper, which mentions ecosystems services 58 times, and in the European biodiversity strategy, which refers to the concept 23 times.
Throughout these documents biodiversity and ecosystems services are generally synonymous and there appears to be an assumption that measures to protect or enhance biodiversity will lead to the increased provision of ecosystems services and vice versa.
In reality, the relationship between the two is much more complex and there is a risk that by not making this explicit, the positive potential of the ecosystems services concept may be undermined. More importantly, the interpretation of this relationship has real implications for policymakers and practitioners.
The nature of the relationship
Our understanding of how biodiversity relates to ecosystems services is still in its infancy. The most established way to consider this relationship is that biodiversity is a central part of the machinery that provides ecosystems services. If this machinery is damaged or removed, then the services we receive decrease and can stop, irreversibly.
There is, however, a huge amount of uncertainty in this description. The extent to which biodiversity can be reduced and service provision remain stable is unknown in almost all cases, because thresholds are context specific. As such, the condition of ecosystems services is generally unclear.
This signals a core difference between the two. Essentially, while ecosystems services have a provable monetary value, it is hard to measure the condition of those services, and while biodiversity can be measured, it is difficult to assign a value to species or habitats.
The UK’s woodlands, for example, provide a range of goods and services in the form of timber products, carbon storage and a venue for recreation. They are also one of the UK’s most biodiverse habitats. Managing woodlands to balance these various, and often competing, aspects is a challenge: more trees do not equal more wildlife, and more wildlife does not equal more timber products.
This conflict between service provision and biodiversity has led to significant revision of the UN’s reducing emissions from deforestation and forest degradation (REDD) programme. REDD provides payments to forest managers to maintain trees to act as a carbon store.
Initially the system did not recognise the need to manage biodiversity separately, the assumption being that protecting trees would protect biodiversity. It was feared also that projects would focus on carbon storage alone. As a result, the UN has since launched REDD+, which differentiates between payments for ecosystems services and biodiversity management.
Cultural services are harder to quantify and value. For example, how much is a walk in a park worth? Valuation is possible by assessing individuals’ decisions and opinions regarding the natural environment. One of the clearest aspects of valuing cultural services is that experiencing the environment is core to assessing its worth. There is value in knowing there are woods nearby, but visiting the woods exceeds this “existence value”.
Aside from the difficulties in placing a value on cultural services, there are also conflicts between maximising such services, by increasing visitor numbers, and delivering biodiversity objectives. Conservation activities, such as setting land aside for animal grazing, may be considered as detrimental to recreational use.
When looking more broadly at ecosystems services another consideration is the need for inputs. For example, the value of a fish in the sea is not realised without a fishing net. Effectively, many ecosystems services do not exist without human or capital input. Unlike biodiversity, ecosystems services often require additional infrastructure that in itself may impact biodiversity.
Separate elements
Considering biodiversity and ecosystems services separately, and their management and enhancement activities as potentially different, has important implications for policymakers and practitioners.
In the first instance, it requires us to understand that biodiversity and, to some extent, ecosystems services are area specific and cannot be replicated as and when they are required. There is, therefore, a need to consider local context and priorities. This can mean focusing on a specific element of biodiversity, such as a target species, in some areas while prioritising ecosystems services, such as flood regulation, in others.
This is not a binary choice; in many circumstances, management and enhancement activities will deliver both improved biodiversity and ecosystems services, but it is not enough to assume this. Rather, it is vital to understand ecosystems services and biodiversity as separate, but related, aspects of the natural environment. Policymakers and professionals then need to consider local priorities within the national context, as well as the potential of the area. For example, is there a local need to improve flood defences or protect a particular species?
Realising ecosystems services through potential tradeoffs with biodiversity is something proposed in the UK national ecosystem assessment. Its lead author, Ian Bateman, suggested there could be significant increases in ecosystems services if low-quality grassland currently used for low-intensity agriculture were to be enhanced through afforestation. In particular, he suggested areas nearest to cities be prioritised as this is where cultural services could be enhanced most efficiently.
Bateman’s suggestion signals one of the potential benefits of considering ecosystems services and biodiversity separately. It reveals our ability to pull apart individual services and consider priorities and potential trade-offs.
The prioritisation of ecosystems services is not new. We do it when we prioritise growing food, for example, over other services, such as water purification. It’s also true that particular aspects of biodiversity provide different ecosystems services, so when we prioritise biodiversity we also prioritise certain ecosystems services. We might as well make this trade-off explicit and consider the potential benefits.
Arguing that the environment is an asset that should be optimised is not particularly appealing, but what it lacks in poetry it makes up for in power and, arguably, represents the logical evolution of ecosystems services thinking.
When considering the relationship between biodiversity and ecosystems services it is worth remembering that the primary driver of natural environment policy has been to deliver biological outcomes. With this background there is potentially an argument that we should have a hierarchical relationship, with biodiversity taking priority over ecosystems services. If so, such prioritisation should be explicit, considered and transparent.
By conflating biodiversity and ecosystems services, existing UK policy has potentially missed an opportunity, but thankfully the flexibility of the framework allows for decision-makers to separate and prioritise biodiversity and ecosystems services on local needs.
Considering biodiversity and ecosystems services as individual aspects of the same complex system gives us the potential to create a more honest and effective discussion about how we are managing and enhancing the natural environment.
