participatory plant breeding practices in order to incorporate the local community into the work. Preserving cereal landraces Preservation efforts for cereal strains are ongoing including in situ and in online-searchable germplasm collections (seed banks), coordinated by Biodiversity International and the National Institute of Agricultural Botany (NIAB, UK). However, more may need to be done, because plant genetic variety, the source of crop health and seed quality, depends on a diversity of landraces and other traditionally used varieties. Efforts () were mostly focused on Iberia, the Balkans, and European Russia, and dominated by species from mountainous areas. Despite their incompleteness, these efforts have been described as "crucial in preventing the extinction of many of these local ecotypes". An agricultural study published in 2008 showed that landrace cereal crops began to decline in Europe in the 19th century such that cereal landraces "have largely fallen out of use" in Europe. Landrace cultivation in central and northwest Europe was almost eradicated by the early 20th century, due to economic pressure to grow improved, modern cultivars. While many in the region are already extinct, some have survived by being passed from generation to generation, and have also been revived by enthusiasts outside Europe to preserve European agriculture and food culture elsewhere. These survivals are usually for specific uses, such as thatch, and traditional European cuisine and craft beer brewing. Plants Plant landrace development The label landrace includes regional cultigens that are genetically heterogeneous, but with enough characteristics in common to permit their recognition as a group. These characteristics are used by farmers to manage diversity and purity within landraces. In some cultures, development of new landraces is typically limited to members of specific social groups, such as women or shaman. Maintaining existing landraces, like developing new landraces, requires that farmers be able to identify crop-specific characteristics and that those characteristics are passed on to following generations. Over time, the process of identifying the distinguishing characteristic or characteristics of a new landrace is reinforced by cultivation processes; for example, descendants of a plant that is notably drought tolerant may become iteratively more so through selective breeding as farmers regard it as better for dry areas and prioritize planting it in those locations. This is one way in which farming systems can develop a portfolio of landraces over time that have specific ecological niches and uses. Conversely, modern cultivars can also be developed into a landrace