Rooting by wild boar can help maintain biodiversity in priority calcareous grasslands, but management must be considered carefully – European Commission

Report on the Ecological Role of Wild Boar in Calcareous Grassland Conservation

Aligning Ecosystem Management with Sustainable Development Goal 15

The conservation of calcareous grasslands, ecologically vital ecosystems protected under the EU Habitats Directive, is a critical component in achieving Sustainable Development Goal 15 (Life on Land). This goal aims to protect, restore, and promote the sustainable use of terrestrial ecosystems and halt biodiversity loss. However, these habitats have experienced significant decline across Europe due to land-use changes and ecological succession, directly challenging the targets set forth in SDG 15.

• Ecological Significance: Calcareous grasslands support high species diversity when managed effectively.
• Threats: The primary threats are agricultural abandonment and the natural transition of grassland into scrub and woodland, leading to habitat and biodiversity loss.
• SDG Relevance: The degradation of these semi-natural habitats undermines Target 15.1 (conserve and restore terrestrial ecosystems) and Target 15.5 (halt the loss of biodiversity).

Research into Natural Processes for Habitat Restoration

Study Objectives and Methodology

A study was conducted to investigate how native wild mammals, specifically wild boar (Sus scrofa), could contribute to the maintenance of calcareous grasslands, offering a nature-based solution aligned with SDG principles. The research focused on the impact of rooting—a natural foraging behavior—on plant community structure and its potential to reverse ecological succession.

1. Location: The study was performed in Hainich National Park, Germany, within a 600-hectare area of semi-open calcareous grassland that has been without regular management since 1997.
2. Method: Researchers analyzed 60 paired plots. Half of the plots were subject to natural rooting by wild boar during the winter, while the other half served as controls.
3. Data Collection: Vegetation surveys were conducted in the summer to assess cover of bare soil, plant litter, moss, grasses, and herbs, providing a quantitative measure of the boar’s impact.

Key Findings: Advancing SDG 15 (Life on Land) through Natural Ecosystem Engineering

Impact on Biodiversity and Ecological Succession

The research revealed that the rooting activity of wild boar has a positive effect on the biodiversity of abandoned calcareous grasslands, directly supporting the objectives of SDG 15.5 to protect threatened species and prevent habitat degradation.

• Increased Diversity: Plots rooted by wild boar exhibited significantly higher plant species richness and diversity. A total of 155 plant species were identified, including three red-listed threatened species, highlighting the habitat’s importance for conservation.
• Slowing Succession: The disturbance created by rooting slowed the process of ecological succession. Boar-rooted areas had more bare soil and herbs, and less plant litter, moss, dominant grasses, and shrubs compared to control plots.
• Habitat Creation: The creation of bare soil patches by rooting provided colonization opportunities for characteristic calcareous grassland plant species, which were being outcompeted in the undisturbed control plots.

Policy Implications and Recommendations for Sustainable Management

Integrating Natural Processes into Conservation Strategy

The study’s results suggest that incorporating the natural behavior of native species like wild boar into conservation management can be an effective strategy for maintaining threatened ecosystems and meeting international biodiversity commitments.

Recommendations for Achieving SDG 15 Targets

1. Recognize Ecological Roles: Conservation management plans for calcareous grasslands should recognize and allow for controlled levels of wild boar rooting to maintain habitat integrity and biodiversity.
2. Adopt a Hybrid Approach: A combination of management techniques may be necessary. This could involve allowing natural processes to lead in some areas while using traditional methods like grazing with domestic livestock in others to achieve optimal conservation outcomes.
3. Implement Monitoring Programs: To prevent excessive disturbance that could harm the ecosystem, careful and continuous monitoring of wild boar populations is essential. This ensures their impact remains beneficial and contributes positively to the goals of SDG 15.

Source

van Leeuwen, B. O., Tuinder, Q., Fartmann, T., Scherer, G., Klamm, A., Schellenberg, M., Vergeer, P., Jansen, P. A. (2025) Effects of wild boar (Sus scrofa) rooting on abandoned calcareous grassland in Hainich National Park, Germany. Global Ecology and Conservation 59:e03535

Analysis of Sustainable Development Goals (SDGs) in the Article

1. Which SDGs are addressed or connected to the issues highlighted in the article?

The primary SDG addressed in the article is SDG 15: Life on Land. The entire article focuses on the conservation and management of a specific terrestrial ecosystem and its biodiversity.

• Detailed Explanation: The article discusses “calcareous grasslands,” which are described as “ecologically important, threatened and relatively rare ecosystems.” It explores methods to maintain their “high species diversity” and prevent their degradation and transition into woodland. This directly aligns with the core objective of SDG 15, which is to “protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss.” The study conducted in Hainich National Park is a clear example of research aimed at understanding and improving the conservation of life on land.

2. What specific targets under those SDGs can be identified based on the article’s content?

Based on the article’s focus on ecosystem protection, biodiversity, and land degradation, the following specific targets under SDG 15 can be identified:

1. Target 15.1: By 2020, ensure the conservation, restoration and sustainable use of terrestrial and inland freshwater ecosystems and their services, in particular forests, wetlands, mountains and drylands, in line with obligations under international agreements.
   • Explanation: The article highlights that calcareous grasslands are listed in Annex I of the EU Habitats Directive, which requires member states to “designate, protect and manage them.” This demonstrates an effort to conserve a specific terrestrial ecosystem in line with an international agreement. The research itself explores sustainable management practices (wild boar rooting, domestic livestock grazing) to maintain this ecosystem.
2. Target 15.3: By 2030, combat desertification, restore degraded land and soil, including land affected by desertification, drought and floods, and strive to achieve a land degradation-neutral world.
   • Explanation: The article states that the “quality and abundance of calcareous grasslands has declined significantly in Europe over the last century, due to changing land use and management.” This decline is a form of land degradation. The study investigates how wild boar rooting can “slow the succession process,” which is the mechanism of degradation for this habitat, thereby contributing to the goal of restoring and halting the degradation of this land type.
3. Target 15.5: Take urgent and significant action to reduce the degradation of natural habitats, halt the loss of biodiversity and, by 2020, protect and prevent the extinction of threatened species.
   • Explanation: This target is central to the article. The calcareous grasslands are described as “threatened” habitats. The study’s findings show that wild boar rooting led to higher “species richness and diversity” and supported “three red-listed threatened species.” This directly addresses the goals of reducing habitat degradation, halting biodiversity loss, and protecting threatened species.
4. Target 15.9: By 2020, integrate ecosystem and biodiversity values into national and local planning, development processes, poverty reduction strategies and accounts.
   • Explanation: The existence of the EU Habitats Directive and the designation of the study area as part of “Hainich National Park” show that biodiversity values have been integrated into regional and national planning. The researchers’ recommendation that “the management of such areas recognises this and allows for controlled levels of boar rooting” is a call to further integrate these scientific findings into local management plans.

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

Yes, the article mentions and implies several quantitative and qualitative indicators that can be used to measure progress.

1. Indicators for Habitat and Ecosystem Health (Targets 15.1, 15.3, 15.5):
   • Species Richness and Diversity: The researchers explicitly measured and “found that species richness and diversity were both higher in the rooted plots.” This is a direct indicator of biodiversity.
   • Vegetation Cover Composition: The study surveyed “summer vegetation cover including bare soil, plant litter, moss, grasses and herbs.” The finding that rooted areas had “more bare soil and more herbs, less plant litter, less moss, less dominant grasses and fewer shrubs” provides a set of measurable indicators to track the reversal of ecological succession (degradation).
   • Area of Protected Habitats: The article mentions that Hainich National Park is 7,500 hectares and contains “600ha of semi-open calcareous grassland.” The proportion of this threatened habitat type under official protection is a key indicator.
2. Indicators for Threatened Species (Target 15.5):
   • Status of Threatened Species: The identification of “three red-listed threatened species” within the plots serves as an indicator related to the Red List Index. Monitoring the population and health of these species would measure progress in protecting them.
3. Indicators for Policy and Management Integration (Target 15.9):
   • Existence of Protective Legislation and Designations: The mention of the “EU Habitats Directive” and the “Hainich National Park” are qualitative indicators that biodiversity values are integrated into policy.
   • Adoption of Management Plans: The recommendation to allow “controlled levels of boar rooting” and to perform “careful monitoring of wild boar populations” implies that the adoption and implementation of such science-based management plans would be an indicator of progress.

SDGs, Targets, and Indicators Summary Table

Source: environment.ec.europa.eu