Green treasures: Investigating the biodiversity potential of equine yards through the presence and quality of landscape features in the Netherlands

on the one hand and the efforts regarding maintenance on the other when developing new landscape designs. Cost-benefit analyses will need to determine how yard owners can best balance biodiversity value, equine health and welfare and business costs in light of geo- graphic restrictions. Limitations While this citizen science study offers valuable insights into the presence and quality of small landscape features (LFs) on equine yards, some limitations should be taken into account. As data collection relies on voluntary participation, equine yard owners may be more likely to have an interest in or knowledge about aspects relating to biodiversity, potentially leading to an overrepresentation of certain types of properties or specific practices [64]. This bias could affect the generalizability of the findings to all equine properties. For example, results from the study may potentially overestimate the PPC on equine yards, and the actual percentage may thus be lower. This, however, only emphasizes what can be achieved, with these yards acting as model yards that others can follow. What is more, participants may have varying levels of expertise and commitment, leading to potential variations in data quality and consistency [65]. As a result, differences in data col- lection techniques, accuracy, and reporting standards can introduce noise into the dataset. However, some studies have shown that citizen scientists may, in fact, produce highly accurate results either due to awareness of their own novice status [66] or due to personal levels of com- petence [67].

The current study’s focus on equine properties in the Netherlands may limit the generaliz- ability of the findings to other regions with different environmental conditions, land use pat- terns, and equine husbandry practices. Another variable that was also not measured in this study is how PPC may be influenced by the purpose of a yard, for example riding school, train- ing stables or stud farms. Future research should investigate how the PPC of LFs varies among yard types and also among different countries and to understand how levels of biodiversity may be related to the PPC and types of LFs on a property. Despite these limitations, a citizen science approach can provide a valuable avenue for gathering data on LFs in equine properties, offering insights that may not be obtainable through traditional research methods. Careful consideration of these limitations is essential when interpreting and applying the study’s find- ings to broader contexts and policy recommendations. Conclusion The current paper highlights the potential for the equine industry to contribute to the restora- tion of ecosystem services and the preservation of biodiversity through the integration of land- scape features. However, despite encouraging results for the PPC of LFs on equine properties, the considerable variation between yards indicates that much remains to be done to integrate principles of biodiversity in equine yard design. Key factors influencing landscape PPC included yard size, the number of landscape fea-

tures, and the type of features. Smaller yards with more features had higher PPC and landscape heterogeneity, which likely enhance biodiversity. Linear landscape features such as tree rows, buffer strips, wild hedges, and flowering strips explained variation in the level of landscape fea- ture coverage. To encourage more biodiversity on equestrian properties, tailored strategies should con- sider the diverse factors influencing equine yard design, including existing knowledge, client demands, financial considerations, and equine health and welfare. PLOS ONE Biodiversity potential of equine yards through landscape features PLOS ONE | https://doi.org/10.1371/journal.pone.0301168 April 11, 2024 12 / 16