What Do Fast-Growing Plantations Really Replace? A Better Baseline for energy crop's LCA

Environmental assessments of fast-growing plantations often begin with a deceptively simple assumption: that the plantation replaces an average cereal field. Yet, a realistic baseline is not a technical detail. It is part of the system being assessed. Whether willow, poplar or hybrid aspen replaces winter wheat, spring barley, temporary grassland or fallow land can substantially influence estimates of greenhouse-gas balances, soil carbon, nutrient losses, biodiversity effects and opportunity costs. For this reason, understanding where plantations are established, and what they replace, is essential for credible life-cycle assessment, land-use modelling and bioeconomy planning.

A 30-year assessment of fast-growing plantations in Sweden provides one of the most detailed empirical baselines currently available. The study traced the development of willow, poplar and hybrid aspen plantations between 1986 and 2017, combining plantation records, agricultural land-register data and spatial analysis. The results showed that willow remained the dominant system, but its area declined from approximately 14,000 ha around 2001 to 7,785 ha in 2017. Poplar and hybrid aspen partly offset this decline, reaching 1,738 ha and 676 ha, respectively, by 2017. In total, Sweden still maintained approximately 10,200 ha of fast-growing woody plantations, although their composition, location and agricultural context changed markedly over time. The full analysis is available here.

The results also showed that plantation establishment cannot be separated from changing policies and agricultural markets. Willow expansion was initially linked to Swedish policy support for energy crops, whereas its subsequent decline coincided with reduced incentives and rising cereal prices after 2007. Average cereal prices increased sharply relative to the 1990–2006 period, by approximately 49% for wheat, 40% for barley and 22% for oats. At the same time, many former willow plantations returned to cereal cultivation. However, new plantations were not established only on cereal land. In 2016, new willow plantations were commonly associated with former spring barley, winter wheat, temporary grassland and fallow land. Poplar plantations showed an even clearer association with lower-intensity agricultural land uses, particularly fallow land and temporary grass. These replacement patterns provide a practical basis for defining differentiated reference scenarios.

This distinction matters greatly for LCA. A plantation replacing intensively managed cereal land may generate different environmental trade-offs than one established on fallow land or temporary grassland, where fertiliser use, machinery inputs and baseline carbon dynamics are already lower. Treating all plantation establishment as a cereal-to-wood transition may therefore overestimate some environmental benefits or overlook relevant impacts. Rather than relying on a single generic counterfactual, future assessments could use a weighted portfolio of agricultural reference systems, reflecting the observed shares of cereals, grasses and fallow land replaced by each plantation type. Such an approach would make evaluations of short-rotation woody crops more spatially realistic, more transparent and more relevant for policy.

The study also illustrates that plantation systems are dynamic rather than uniform. Willow plantations increasingly concentrated in southern and more productive agricultural areas, whereas poplar tended to expand on less productive land. Smaller plantation units became more frequent, particularly those below one hectare, while large systems above ten hectares became relatively uncommon. These patterns reflect not only land availability, but also changing farmer preferences, local biomass markets, management choices and wider agricultural conditions. For researchers seeking robust baseline scenarios for plantations, the central message is clear: the environmental performance of a plantation cannot be assessed independently from the land-use trajectory that made it possible.

Further information: Research on biomass production, plantation forestry and land-use dynamics is available through the Biomass Production research group at the University of Eastern Finland. Further publications and activities can also be found at sites.uef.fi/biopro.

Reference

Xu, X., & Mola-Yudego, B. (2021). Where and when are plantations established? Land-use replacement patterns of fast-growing plantations on agricultural land. Biomass and Bioenergy, 144, Article 105921. https://doi.org/10.1016/j.biombioe.2020.105921

For related research, visit the Biomass Production research group, University of Eastern Finland.

Mixed forests and wildfires

Mixed hashtag#forests play a fundamental ecological role in our landscapes, widely celebrated for increasing biodiversity and providing a broad range of essential ecosystem services. In forest hashtag#ecology and management, a prevailing assumption is that these mixed forests are inherently better and more resilient to natural disturbances, particularly wildfires, than homogenous pure stands. We often theorise that the higher structural diversity and varied morphological traits found in mixed species provide a natural, protective buffer against fire spread and severity.

However, to robustly check this hypothesis, we must move beyond theoretical assumptions and rely on extensive empirical evidence. This is exactly what we tried to do utilising a massive dataset from the Spanish National Forest Inventory (NFI) to examine post-fire tree mortality across 2,782 plots and over 30,000 trees over a two-decade period.

The main results of this analysis challenged our traditional expectations: mixed stands can actually suffer significantly higher post-fire mortality than pure stands. We found that combining tree species with differing fire-related strategies (such as mixing hashtag#fire-resistant species with fire-resilient ones like Pinus nigra and Pinus halepensis) often exacerbates stand hashtag#vulnerability rather than mitigating it.

This increased hashtag#damage occurs because combining different structural strategies can create a vertical "ladder effect" between the canopy and understory, accumulating higher biomass densities in intermediate layers and ultimately facilitating the spread of fire. While there are notable exceptions where mixing species actually helps, such as the introduction of Quercus robur which was shown to lower mortality in some pine stands, the overarching lesson is clear. We must reconsider the blanket assumption that "mixed is always better" and carefully tailor our management of mixed forests based on specific functional fire traits to truly build fire-resistant landscapes.

Find more: Peris‑Llopis, M., Mola‑Yudego, B., Berninger, F., Garcia‑Gonzalo, J., & González‑Olabarria, J. R. (2024). Impact of species composition on fire‑induced stand damage in Spanish forests. https://doi.org/10.1038/s41598-024-59210-4

Thanks to eco2adapt, Suomen Kulttuurirahasto / Finnish Cultural Foundation, European Forest Institute, European Research Executive Agency (REA), Marie Skłodowska-Curie Actions, Generalitat de Catalunya CERCA

Mapping yields of energy crops in Northern Europe

Willow plantations have long been considered a promising source of biomass for bioenergy in northern Europe. Yet, one essential question remains for investors, planners and policymakers: how much biomass can realistically be produced, and where? It is easy to discuss potential in broad terms, but sound supply planning requires spatially explicit estimates grounded in real production data.

This study used harvesting records from 1,790 commercial willow plantations in Sweden and combined them with climatic variables to estimate productivity across northern Europe. Rather than relying exclusively on experimental plots, the analysis was based on commercial plantations. The resulting estimates therefore reflected biomass yields that can be more realistically harvested and mobilised under operational conditions. The models were extended across Sweden, Norway, Denmark, Finland, Estonia, Latvia, Lithuania, and the Baltic coastal regions of Germany and Poland.

The results revealed strong spatial variation in yield potential. Precipitation during the growing season, together with key temperature variables, explained an important share of this variation. Under high-performance conditions, estimated first-rotation yields exceeded 7 oven-dry tonnes per hectare per year along the Baltic coast of Germany, 6 in Denmark, and 5 along the Baltic coast of Poland. Across much of the remaining study area, estimated yields ranged between 4 and 5 oven-dry tonnes per hectare per year. These findings showed that neither land nor climate provides equal opportunities for willow production, even within broadly similar northern European conditions.

The practical relevance of the study lies precisely in this spatial perspective. Biomass strategies should not be discussed only in terms of total land availability, but also in relation to realistic productivity, regional differences and the climatic limits of the crop. Better yield estimates can improve energy-system planning, reduce overly optimistic supply assumptions, and support more informed decisions on where willow could form a viable component of the renewable energy mix.

Climate, however, did not explain everything. Soil conditions, clone selection and management remained highly important, particularly in the most productive plantations. The maps should therefore not be interpreted as fixed predictions for every field, but as a robust reference for regional planning, comparison and future improvement. For bioeconomy and renewable-energy research, this represented an important step towards more realistic assessments of biomass supply.

Reference
Mola-Yudego, B., Rahlf, J., Astrup, R., & Dimitriou, I. (2016). Spatial yield estimates of fast-growing willow plantations for energy based on climatic variables in northern Europe. GCB Bioenergy, 8, 1093–1105. https://doi.org/10.1111/gcbb.12332

gcbb12332-sup-0001-FigS1.tifTIFF image, 5.9 MB

gcbb12332-sup-0002-FigS2.tifTIFF image, 5.9 MB

gcbb12332-sup-0003-FigS3.tifTIFF image, 5.5 MB

Where We Plant Matters: Can Poplar Plantations Help Birds Cross Fragmented Farmland?

Across much of Europe, agricultural intensification has broken forest habitats into smaller and more isolated patches, making it harder for forest birds to move through the landscape. This study explored whether poplar plantations, which are already widespread in many farming areas, can help reconnect those fragmented habitats. Using two agricultural sub-catchments in Spain and France, the authors modelled how three forest bird species with different dispersal abilities responded when plantations were added to forest networks inside and outside Natura 2000 areas.

The results showed that poplar plantations can indeed improve connectivity, but not simply by adding more tree cover everywhere. Their value depended strongly on where they were located. Plantations were most useful when they acted as stepping stones between larger forest patches, especially along river corridors. The benefits were also species-specific: birds with medium or long dispersal abilities gained more than short-distance species, which still need habitat patches to be very close together. In other words, the study showed that landscape design matters as much as plantation area.

This is an important message for both land managers and policy makers. Poplar plantations should not be treated as a universal substitute for natural forests, but they can function as complementary elements in fragmented agricultural landscapes. Strategically placed plantations may strengthen ecological connectivity, support biodiversity goals, and improve the wider green infrastructure around protected areas. At the same time, the authors stress that location remains crucial, because plantations may be less helpful in some settings and can even conflict with the needs of open-habitat species if poorly placed. The main lesson is simple but powerful: in biodiversity-friendly land use planning, where we plant may matter as much as what we plant.

Pineda-Zapata, S., Morán-Ordoñez, A., Mola-Yudego, B., & Duflot, R. (2026). Strategic placement of plantations enhances forest connectivity for birds in agricultural landscapes. Landscape Ecology, 41, Article 54. https://doi.org/10.1007/s10980-026-02316-z

Find more information at: https://sites.uef.fi/biopro/

As Europe accelerates its shift toward a low-carbon economy, the pressure to deliver sustainable biomass is rising fast, yet the hardest question is no longer only what to grow, it is where to grow it. Fast-growing plantations and perennial energy grasses can underpin biofuels and biomaterials, while also supporting carbon storage, water protection, and soil functions. However, when these systems expand as large, poorly integrated blocks, they can simplify land use patterns, weaken habitat variety, and reduce ecological resilience. The promise of the bioeconomy, therefore, depends on spatial intelligence: biomass systems need to be placed as part of the landscape, not imposed on top of it.

A recent open-access study addressed this challenge by building one of the most comprehensive empirical pictures yet of biomass production systems across Europe. Using harmonised spatial data for 426,783 fields and stands, covering 2,140,568 hectares across 17 countries, the authors characterised seven representative systems, including eucalypt, radiata pine, black locust, poplar and hybrid aspen, willow, miscanthus, and reed canary grass. They then assessed the land-use context around each site using 1 km buffers and CORINE land cover, translating “how mixed is the surrounding landscape?” into a Land Use Diversity Index based on Shannon diversity. The result was a practical lens for policy and planning: it showed not just where biomass is today, but where it is likely to diversify, or homogenise, the landscapes around it.

The key insight was that context dominates: the same crop can be either a corridor of diversity or an engine of simplification, depending on where it is inserted. Willow stood out as the strongest candidate for diversification, with 57% of willow plantations located in homogeneous, agriculture-dominated areas, where woody strips can introduce structural variety and potentially strengthen multifunctionality. Poplar and black locust also showed meaningful opportunities, with sizeable shares of stands situated where they could add “forested elements” into agricultural matrices. By contrast, miscanthus was often concentrated in low-diversity agricultural settings, suggesting that, without deliberate spatial planning, it may do little to raise local land-use diversity. The study also highlighted a recurring risk signal: biomass areas were highly unevenly distributed, with the largest 20% of stands accounting for the majority of total area, and thousands of very large polygons, a pattern that can translate into landscape dominance when not carefully governed. A sustainable bioeconomy is a design problem, and better maps, better metrics, and better placement rules are as important as better crops.

Read more:
Pineda-Zapata, S., & Mola-Yudego, B. (2025). European biomass production systems: Characterization and potential contribution to land use diversity. GCB Bioenergy, 17, e70057. https://doi.org/10.1111/gcbb.70057
DOI: 10.1111/gcbb.70057

Understanding bioenergy conflicts: Case of a jatropha project in Kenya’s Tana Delta

Bioenergy is often presented as a double opportunity, to reduce dependence on fossil fuels while also promoting rural development. But large-scale bioenergy projects do not unfold in empty landscapes. They enter places with existing land uses, rights, institutions, and histories of inequality. When those realities are ignored, a project framed as green development can rapidly become a source of conflict.

In this paper, we examined the case of a proposed large jatropha plantation in Kenya’s Tana Delta, using Ethical Analysis to understand the positions, interests, and values of the main stakeholders. The case was not only about biodiesel. It was also about who has the right to decide over land, whose livelihoods count, and how “development” itself is understood by different actors.

What we found was that the conflict was structured around four major issues: land tenure, trade-offs between economic and environmental benefits, representation and power relations, and different approaches to development and sustainability. Some actors emphasized jobs, investment and local growth. Others stressed biodiversity, grazing rights, traditional land uses, and the risks of weakly regulated land deals. The disagreement, therefore, was not simply about being for or against bioenergy, but about what kind of rural future was being imposed, and for whom.

Perhaps the most important message was that many of the tensions could have been anticipated. The study identified shortcomings in technical feasibility studies, limited community participation, weak consultation processes, and an insufficient regulatory framework. In that sense, the problem was not only the crop or the investor, but the broader governance setting that allowed such a project to move forward without properly addressing land tenure, local rights, and competing claims over the landscape.

For me, this is where the study still feels very relevant. If hashtag#bioenergy is to contribute to hashtag#climate goals and hashtag#development, it cannot rely only on promises of investment or emission reductions. It also needs credible feasibility, transparent institutions, and meaningful participation from the start. The paper points to Free, Prior and Informed Consent, stronger oversight, and better policy coordination as necessary steps. That is a simple but important lesson for hashtag#policy and hashtag#governance: sustainability is not only about the final product, but also about the process through which land use decisions are made.

Arevalo, J., Ochieng, R., Mola-Yudego, B., & Gritten, D. (2014). Land Use Policy, 41, 138–148. https://doi.org/10.1016/j.landusepol.2014.05.002