Use and conservation of rare and declining arable species for restoring agro-ecosystems

In recent decades, the growing recognition of environmental challenges posed by intensive agricultural practices has led to increased interest in the conservation of plant species within agroecosystems. Conventionally, the field of conservation biology has focused on protecting biodiversity in natural habitats. However, it is increasingly understood that biodiversity extends beyond protected areas to human-dominated landscapes, particularly agricultural ones. The global expansion of agriculture, driven by the need to meet the food demands of a growing population, has resulted in widespread land-use changes, habitat destruction, and the decline of plant species, especially those integral to traditional farming systems. The intensification of agricultural practices, including monocropping, extensive use of chemical fertilisers and pesticides, and the removal of natural habitats has further accelerated the loss of arable plant species. Many of these species, once essential for ecosystem services such as soil health, pollination, and pest control, are now considered weeds and systematically eradicated. Despite these challenges, there is growing recognition of the potential for integrating biodiversity conservation into agricultural landscapes. Sustainable farming practices, such as organic farming, low-input agriculture, and agroecology, have emerged as promising alternatives to high-intensity agriculture. These practices support greater plant and animal diversity and offer solutions to environmental issues like soil degradation, reduced water quality, and pollinator loss. The conservation of rare and threatened plants within agroecosystems, particularly arable species, is crucial for preserving biodiversity and restoring ecosystem functions. This thesis explores fundamental aspects of plant conservation within agroecosystems, with a particular emphasis on the conservation of rare and threatened arable species. It examines the use of conservation translocations as a strategy for the reintroduction of these species, analysing the competitive interactions between arable species and crops. Additionally, it discusses the ecological and genetic aspects of species such as C. cyanus (cornflower). The research presented provides insights into the factors influencing the success of conservation translocations, the importance of integrating biodiversity into agricultural systems, and strategies for promoting the coexistence of agricultural productivity and plant conservation. The findings contribute to the development of sustainable agricultural models that respect biodiversity while maintaining agricultural productivity.