Using Remote Sensing to Study How Wild Horses Reduce Shrub and Grassland Biomass

Greg Howard
3rd July, 2024

Using Remote Sensing to Study How Wild Horses Reduce Shrub and Grassland Biomass

Image Source: Hassan OUAJBIR (photographer)

Key Findings

  • In Galicia, Spain, feral horses were used to graze on gorse to reduce wildfire risk
  • Grazed areas showed a consistent reduction in wildfire spread rates compared to ungrazed areas
  • Using drones for data collection provided a fast and cost-effective way to assess biomass and wildfire risks
Forests in Galicia, northwestern Spain, are frequently ravaged by wildfires, leading to significant environmental and economic damage. The increasing virulence of these fires, exacerbated by climate change, poses a heightened risk to both natural landscapes and human populations. Traditional forestry methods to mitigate these fires are costly, prompting the exploration of alternative measures. One such innovative approach involves the use of endemic feral horses (Equus ferus atlanticus) to graze on gorse (Ulex europaeus), a thicket-forming shrub that contributes to high fuel loads in these forests. This study, conducted by the University of Freiburg, aimed to evaluate the effectiveness of these horses in reducing forest biomass and, consequently, wildfire risk[1]. The research was carried out in a 100-hectare fenced forest area stocked with 11 feral horses. Four 50 m² enclosed plots were established to prevent the horses from accessing the vegetation within, allowing for a controlled comparison of biomass reduction between grazed and ungrazed areas. From September 2018 to November 2020, data on aboveground biomass were collected using drones (unmanned aerial vehicles, UAVs). This method provided high-resolution, low-cost data collection, which was crucial for assessing wildfire risks over a regional scale. The study found that the areas grazed by horses showed a consistent but small reduction in the surface rate of spread (SROS) of wildfires, with values ranging from 0.55 to 3.10 m/min, compared to 15 to 25 m/min in the ungrazed enclosed plots. This indicates that the presence of feral horses can significantly reduce the rate at which fires spread, making them a valuable tool in wildfire prevention in gorse-dominated landscapes. This finding aligns with earlier research on fire behavior in Mediterranean gorse shrublands, which highlighted the importance of fuel load and moisture content in determining fire intensity and spread[2]. As shrublands mature, their moisture content decreases, leading to higher fire intensity even under moderate weather conditions. This underscores the need for effective fuel control measures, such as the use of grazing animals, to mitigate the risk of catastrophic fires[2]. Moreover, the study's use of UAVs for biomass data collection and fire modeling is a significant advancement. Traditional methods of measuring biomass volumes are time-consuming and labor-intensive, particularly at regional scales. UAVs offer a more efficient alternative, enabling researchers to gather high-resolution data quickly and at a lower cost. This technological approach not only enhances the accuracy of wildfire risk assessments but also supports the implementation of targeted prevention strategies. The research also contributes to the broader discourse on the role of fire in land management and ecosystem health. In regions like Australia, the USA, and some Mediterranean countries, fire is an integral part of land management practices aimed at reducing the likelihood of catastrophic wildfires and maintaining healthy ecosystems[3]. However, in less fire-prone regions such as the UK, the use of fire for land management has been controversial due to concerns about its environmental impacts[3]. This study provides valuable insights into alternative fire prevention methods that could be applicable in various contexts, including those with differing socio-economic and ecological landscapes. In summary, the University of Freiburg's study demonstrates the potential of using feral horses as a natural and cost-effective means of reducing wildfire risk in Galicia's gorse-dominated forests. By integrating advanced UAV technology for data collection, the research offers a robust framework for assessing and mitigating wildfire hazards. This approach not only addresses the immediate need for effective fire prevention strategies but also contributes to the ongoing exploration of sustainable land management practices in fire-prone regions worldwide.

EnvironmentEcologyAnimal Science

References

Main Study

1) Application of remote sensing to understand the role of Galician feral horses in the biomass reduction of a shrub-grassland-dominated landscape

Published 2nd July, 2024

https://doi.org/10.1186/s12862-024-02276-5

Related Studies

2) Factors influencing fire behaviour in shrublands of different stand ages and the implications for using prescribed burning to reduce wildfire risk.

Journal: Journal of environmental management, Issue: Vol 65, Issue 2, Jun 2002

3) Prescribed fire and its impacts on ecosystem services in the UK.

https://doi.org/10.1016/j.scitotenv.2017.12.161


Related Articles

An unhandled error has occurred. Reload 🗙