Applying ecosystem services thinking to natural resource management and conservation decision making

Abstract

As global consumption increases, there is a growing emphasis on the production of food and the use of other resources necessary for life. Consequently, many ecosystems are stressed because their ability to produce market goods is favoured over other critical functions and services that ecosystems provide such as energy transfer, water regulation, nutrient filtering, and carbon sequestration. Capturing these benefits using ecosystem services thinking offers decision makers a methodology for considering the multiple benefits that ecosystems provide. However, gaps in our understanding of how we can make the ecosystem services concept operational remain. Recognising the relationship between natural capital stocks and the provision of ecosystem processes and services is a crucial step in operationalising ecosystem services thinking. I advance this concept by identifying that attributes of natural capital are not uniform in their amenability to change. Hence, the central tenet of this thesis is that management actions targeted at manageable attributes of natural capital stocks is effective for influencing provision of ecosystem services and benefits. I test how management practices influence natural capital stocks that contribute to the provision of required ecosystem services, using a ‘provider group’ approach. Provider groups are sets of species which exhibit attributes which contribute to ecosystem services and benefits. The traditionally farmed grassland system in the Southeastern Carpathians, Romania, is a good example of a multifunctional landscape providing provisioning, regulating, and cultural ecosystem services and thus a useful case study to test this approach. I assigned grassland plant species to provider groups (quality fodder, medical and aromatic compounds, honey, pollen, nitrogen fixation, and conservation concern) based on their characteristics and tested the impact of management practices (abandonment of hay meadows, grazing, and mowing) on species diversity and abundance within each group. Over three quarters (77%) of the 210 unique species sampled during this study contributed to at least one provider group and over a third (36%) contributed to more than one group. I found that different management practices favour certain provider groups over others, and thus supply of certain ecosystem services over others. A more nuanced understanding of the influence of management practices on natural capital stocks can better inform agricultural and conservation policies targeted at sustaining multifunctional landscapes. Incorporation of social data, particularly that describing human behaviour and decision making, is critical to embed the ecosystem services concept into natural resource management policy and practice. Riparian management is a common policy option for mitigating the externalities of land use. A riparian management programme has been running in Taranaki Region, New Zealand for over 20 years providing a useful case study to elicit farmers perceptions and experiences of the pros and cons of planting riparian margins. I found the views of dairy farmers farming the Taranaki ring plain to be varied. Farmers with planted margins reported experiencing many on and off-farm benefits from multi-tier riparian plantings including production, environmental, and social values. This group of farmers identified 32 aspects of riparian vegetation across nine categories, 65% of which were positive aspects and 35% of which were negative aspects. Farmers who had fenced but not planted their riparian margins also believe benefits for water quality, animal safety, and farm management can be achieved from fenced grass strip riparian margins but were less convinced about additional benefits from planting. This group of farmers identified 15 aspects of riparian vegetation across four categories, all of which (100%) were negative aspects. Recognising that farmer’s perceptions and/or experiences vary can help inform how best to structure and deliver policies for sustaining provision of multiple ecosystem services and benefits. Biodiversity offsetting represents a critical application of the ecosystem services concept as trading biodiversity also inherently trades the associated ecosystem service values. Further, trading biodiversity in an offset exchange embodies the manipulation of natural capital stocks, in both the removal of species and habitats and in their replacement or enhancement elsewhere. Currencies used to evaluate offset proposals can either aggregate (combine measures of biodiversity attributes into a composite unit) or disaggregate (individually account for each measured biodiversity attribute of interest). I developed a disaggregated accounting model that balances like-for-like biodiversity trades using a suite of area by condition currencies to individually calculate the net present biodiversity value (NPBV) by which to evaluate no net loss for each biodiversity attribute inputted into the model. The model improves on more aggregated models by enabling increased transparency of biodiversity offsetting proposals, and thus improved decision making processes. This thesis provides an increased understanding of the relationship between management actions and ecosystem services and associated benefits at local scales, and a collection of tools and methods to support decision making targeted at sustaining multifunctional landscapes. Overall, this research illustrates that a natural capital focussed ecosystem services approach provides an opportunity to shift land management towards practices that sustain rather than deplete the natural capacity of ecosystems.