Supporting site planning through monetary values for biomass and nature conservation services from ecosystem accounts

A nationwide German mapping study estimated the monetary value of two ecosystem services—biomass production and nature conservation—to support rural site planning. The analysis found that the biodiversity value assigned to land was substantially higher than the value of agricultural and timber production across most rural land-cover types. Even arable land carried more estimated conservation value than production value after small features such as hedges, ditches, stone walls and wetlands were excluded. The results do not establish that development should proceed according to the highest-value alternative, but they provide a common economic scale for comparing selected environmental losses alongside other planning considerations.

Germany’s site-selection procedures for housing, industry, commerce and infrastructure commonly combine criteria evaluated through different methods, including agricultural and forestry productivity, biodiversity, drinking-water and groundwater protection, carbon storage and recreation. In many multi-criteria analyses, these results are presented side by side, leaving planners to determine how much weight to assign to each factor. Monetary ecosystem-service estimates offer an additional basis for comparison because biomass and biodiversity values can be aggregated and placed alongside other monetary quantities. The approach supplements rather than replaces statutory assessments, site surveys and decisions concerning services that the national accounts do not yet value comprehensively.

Under the United Nations System of Environmental-Economic Accounting used by the researchers, the monetary value of biomass provisioning is based on the economic return generated by an ecosystem service, not the full sales value of crops or timber. The theoretical measure is net profit after accounting for capital, labour and intermediate inputs such as pesticides and fertilisers. Because detailed farm-profit data were unavailable, the pilot study used agricultural lease rates as a proxy. Researchers linked those rates to soil-based measures of agricultural yield potential, using both Germany’s agricultural soil assessment and the Müncheberg Soil Quality Rating to estimate hypothetical lease values across agricultural land.

The model distinguished arable land from grassland using the Land Cover Model Germany for 2012 and 2015. Soil-quality information was available at a comparatively coarse 250-by-250-metre resolution, while the mapped cropland extent was represented on a 5-by-5-metre grid. For grassland, municipal arable-land averages were initially assigned and then adjusted downward using county-level ratios derived from agricultural soil estimates in Bavaria, Thuringia and Saxony. Historical relationships between soil scores and rents were updated to the 2018 lease level before being applied to individual areas. Comparison with national statistics indicated that the modelled leases were lower than the 2018 average by approximately 6.95% overall.

The soil-based approach also had an uneven effect on the distribution of estimated rents. Using an average rental income per soil score tended to assign relatively high values to low-yield land and relatively low values to high-yield land, whereas applying the underlying hedonic relationship directly would have produced a wider spread. Yield potential was also only one of several influences on agricultural lease markets: parcel size, regional land demand and the need to dispose of animal-farm manure can also affect rents. For forests, the researchers instead used average annual net profit per hectare from official statistics as an approximate national value for timber provisioning. The available national figures were not spatially differentiated, which the authors considered less problematic because conservation values dominated the combined monetary value of the forests examined.

Biodiversity was represented physically through biotope value points, a professionally and legally established measure used in German conservation planning. The system accounts for characteristics including naturalness, habitat age, threatened species and the vulnerability of the ecosystem. The national list assigns scores to about 500 ecosystem types, ranging from zero for sealed surfaces to 24 for intact mires, fens and old semi-natural forests; local condition can alter a listed score by as much as three points. Combining this list with national land-cover data, linear features such as watercourses, paths, hedges, tree rows and rocks, and reporting under European nature and water directives produced approximately 300 spatial ecosystem and condition classes covering Germany.

To convert biotope points into monetary values, the researchers examined restoration measures for 43 ecosystem types with available cost data. These measures covered about 1.16 million hectares, equivalent to 3.2% of German land cover. The calculation included the initial and target biotope values, restoration time, one-off investment, land acquisition where needed, annual management costs and any income from marketable products. Present-value costs were divided by the discounted difference in biotope points, and the resulting one-off payment was converted into a constant annual value. The analysis tested discount rates of 2%, 3% and 4% over 25 years, 50 years and an indefinite period.

The cost-based estimate was checked against benefit-based estimates drawn from two contingent-valuation surveys measuring willingness to pay for comprehensive national conservation programmes. After adjustment for inflation, the benefit-based value per biotope point was approximately twice the cost-based value. This difference did not substantially alter the relative ranking of ecosystem types, because both methods assigned much higher values to conservation than to biomass production, but it raised a policy choice for further development of the accounts: whether national biodiversity values should reflect restoration costs, stated willingness to pay, or a wider body of public and compensation measures. The surveyed programmes were also estimated to increase Germany’s total biotope-point stock by only about 6%, supporting an interpretation of their values as marginal willingness to pay for additional points.

When the services were compared nationally, near-natural, unused ecosystems had higher average values than agricultural land and were approximately comparable to forests in monetary terms. Settlement areas were a notable exception: the land value associated with residential or commercial use was much higher than their biodiversity value. That comparison cannot establish that further urban expansion is beneficial, because the analysis excluded several impacts associated with development, including effects on recreation, urban heat, traffic and climate. It also considered only two ecosystem services. Similarly, product turnover should not be confused with ecosystem-service value: converting land may affect capital, labour and input markets, but in a functioning economy with labour shortages and some ability to adjust, the loss is expected to be closer to the service value than to total sales.

Aggregating the two service values produced a result consistent with common German planning patterns. If only biomass provisioning and biodiversity are considered, arable land frequently appears among the least costly locations for settlement, industry and infrastructure. Development often replaces lower-value farmland with higher-value built land, while ecological compensation can convert additional farmland into near-natural habitat or forest. The economic maps therefore did not fundamentally overturn established practice; instead, they supplied a monetary rationale for site searches and strengthened the consideration of biodiversity within them. Final choices would still require consideration of protected-area rules, on-site ecological evidence, and services omitted from the model, including recreation, flood protection and carbon storage.

The estimates are also bounded by scale and time. They describe current values and are intended primarily for relatively small local changes, such as an individual project, rather than abrupt losses, long-lasting transformations or economy-wide conversion. National averages cannot capture the potentially decisive effect of destroying the last site of a highly endangered endemic species, for which field surveys would be necessary. The study was explicitly a pilot, and its detailed statistical uncertainty analysis was limited by available resources. More comprehensive restoration-cost data, better treatment of regional distortions in lease markets, and national estimates of recreation, climate mitigation and flood protection were identified as priorities. Within these limits, the maps show how ecosystem accounting can make a less visible planning consequence explicit: the estimated value of conserving nature can be greater than the value of producing biomass on the same rural land.

Subject of Research: German pilot study valuing biomass and biodiversity ecosystem services for rural site planning

Article Title: Supporting site planning through monetary values for biomass and nature conservation services from ecosystem accounts

Article References: Ekinci, B., Grunewald, K., Meier, S., Schwarz, S., Schweppe-Kraft, B., & Syrbe, R.-U. (2022). Supporting site planning through monetary values for biomass and nature conservation services from ecosystem accounts. One Ecosystem, 7, Article e89706. https://doi.org/10.3897/oneeco.7.e89706

Image Credits: AI Generated

DOI: 10.3897/oneeco.7.e89706

Keywords: ecosystem accounting, biodiversity valuation, biotope value points, biomass services, site planning, agricultural land, nature conservation, environmental economics, Germany, Supporting, site, planning