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

As current findings show, once the descriptor variables of a yard are controlled for, it is the type of features that determines ultimate PPC and provides a good indication of the actual bio- diversity potential of equine yards. Buffer strips, wild hedges, tree rows, flowering strips, embankments and cluttered corners are all features shown to explain variation in the propor- tion LF coverage. Linear landscape features such as tree rows, buffer strips, wild hedges and flowering strips are widely heralded for their potential to preserve or even restore habitat diversity [43]. Due to their diversity in form and function, LFs can serve as effective secondary habitats for various species [44], promoting biodiversity conservation in otherwise species- poor landscapes [45, 46] as well as serving as important landscape corridors. Hedges and trees have been shown to provide multiple benefits, such as air and water filtration, pest control, pollination support, aesthetic and health advantages, erosion reduction, and annual carbon sequestration [47–51]. Flowering strips have been shown to provide a host of ecosystem ser- vices, most notably providing shelter and nectar to pollinators [52, 53] stimulating natural pest control [54] and increasing the aesthetic value of the environment [53, 55]. Equally, embank- ments, often viewed as engineered structures merely designed for flood control and water management, have become increasingly important as unique habitats to foster plant diversity, and enhance ecosystem functions [56, 57]. Current findings provide evidence that between

one-third and one-half of equine yards already integrate a number of these key linear land- scape features that, in equine yards at least, appear to be indicative of a more heterogenous yard design. In the analysis, cluttered corners explained significant variation in PPC demonstrating their significant presence and contribution to landscape diversity. While cluttered corners are often negatively associated with, as the name would suggest, the cluttering of local landscapes and may also pose a certain safety risk for horses if not managed appropriately, they could poten- tially be modified into useful spaces. Such efforts may promote a change in perception of clut- tered corners and in association with the diverse LF, contribute towards a perceptual shift regarding the role of the equine sector in the agro-ecological transition [20, 58]. The majority of equine yards are situated in peri-urban or rural settings, meaning that these yards may well be considered biodiversity ‘connecting hubs’. By linking other rural/agricul- tural properties with natural reserves, equine yards would facilitate interspecies exchange through landscape corridors [45] in areas where urbanisation or agricultural intensification would make it otherwise more difficult. What is more, since equine yards are not merely a source for horse-human interaction, but also for the interaction between humans and nature [39, 59], a more biodiverse-inclusive yard design may also allow visitors to the yard direct access to nature in the course of their interactions with horses.

Therefore, in order to engage a greater number of yard owners in more biodiverse yard design, cohesive strategies need to be employed on how to achieve such a shift. However, one- size-fits-all approaches to encourage the implementation of agri-ecological schemes have largely been found ineffective [60, 61], simply because they generally fail to take the specifics of a farm into account. In an industry as varied as equestrianism, it is important to take the expe- riences of other sectors on board. Specifics of equine yard design are likely to be influenced by a number of factors, ranging from current levels of knowledge and skill, to personal preferences, ideology, client demands, financial considerations, ease of access and efficiency, and, importantly, aspects of equine health and welfare [27, 42, 62, 63]. Additional research is therefore required to investigate how equine yards could make full use of small landscape features while also impacting positively on different aspects of equine behaviour and welfare. In the context of sustainable business operations, it will also be essential to consider the diversity in the "biodiversity value" of different landscape features PLOS ONE Biodiversity potential of equine yards through landscape features PLOS ONE | https://doi.org/10.1371/journal.pone.0301168 April 11, 2024 11 / 16