Successful restoration of heathlands and grasslands associated with long-term habitat preferences of cattle and horses: Insights from GPS tracking.

Overview

• This study investigates how the long-term, year-round grazing behavior of cattle and horses contributes to the restoration of degraded heathlands and grasslands in Central Germany.
• Using over 13 years of GPS tracking combined with vegetation surveys, the research links grazer habitat preferences with changes in vegetation structure to understand restoration mechanisms.

Introduction and Context

• Temperate heathlands and grasslands have been degraded over time due to abandonment and lack of traditional grazing.
• Restoration efforts increasingly rely on long-term, year-round grazing by large herbivores to restore these habitats.
• However, the detailed behavioral mechanisms by which grazing animals influence habitat recovery have not been fully studied.

Methods

• The study used high-resolution GPS tracking data collected over more than 13 years from free-ranging Heck cattle and Konik horses.
• Repeated vegetation surveys were conducted in diverse habitat types: encroachment-derived Calamagrostis epigejos stands, dry sandy grasslands, dry heaths, and pioneer forests.
• The location data were analyzed to quantify habitat preferences of the grazers across different seasons and over the long term.
• Vegetation structural changes were monitored to link grazer behavior with habitat restoration progress.

Key Findings: Seasonal Habitat Preferences

• Habitat preferences varied between habitat types and exhibited strong seasonal differences.
• In summer, both cattle and horses showed strong preference for habitats with productive regrowth due to higher forage quality.
• During winter, preferences weakened; animals showed less selectivity and used habitats more evenly, including those avoided in the growing season like dry heaths and pioneer forests.
• This winter grazing behavior likely enables year-round vegetation management across the landscape.

Long-term Changes in Habitat Preference and Vegetation

• Over the study duration, long-term shifts in habitat preference were noted that coincided with changes in vegetation structure indicating restoration progress.
• Specific vegetation changes included declines in standing biomass, reductions of Calamagrostis epigejos and grass litter, increases in open soil, and expansion of the heath species Calluna vulgaris into an optimal growth phase.
• The decrease in forage-quality contrasts between habitats led to weaker habitat preference patterns and more uniform use of the landscape by the grazers.

Implications for Restoration Practices

• The observed link between grazer behavior and vegetation dynamics provides strong empirical evidence that extensive, year-round grazing is necessary for sustained habitat restoration.
• Summer-only grazing would not achieve the same stable long-term outcomes because it does not promote the broad spatial use of habitats seen in winter.
• Grazers’ winter use of less preferred habitats assists in controlling encroachment and maintaining open habitats critical for heathland and sandy grassland restoration.
• These findings emphasize the importance of maintaining diverse habitat use by grazers throughout the entire year to facilitate balanced vegetation development and ecosystem recovery.

Conclusions

• The study highlights the behavioral ecology of large herbivores as a critical driver of habitat restoration in temperate heathlands and grasslands.
• It provides a rare, long-term dataset showing how year-round grazing behavior and vegetation restoration are interconnected.
• Effective conservation grazing programs should incorporate continuous grazing strategies and monitor seasonal habitat use to promote successful ecosystem recovery.