A trait-based approach in a Mediterranean vineyard: Effects of agricultural management on the functional structure of plant communities

In recent years, rainfed vineyards in the Mediterranean basin are being replaced by irrigated vineyards in some areas, a phenomenon that is expected to increase due to climate change. At the same time, the use of plant cover in vineyards has emerged as an alternative to other weed management practices (e.g., herbicide, tillage). Knowing how weed communities respond to these practices is essential to develop new and more sustainable vineyard management systems. However, there is a lack of research on this issue. This work examines, from a trait-based approach, the effects of weed management (herbicide, mowing, tillage), and deficit drip irrigation (irrigated, non-irrigated) on the functional structure of plant communities in a Mediterranean vineyard. Plant sampling was conducted from 2015 to 2018 in a previously established experiment in 2008. The experimental design was randomised blocks with four replications, including four management systems. Data for ten plant traits were collected from several databases and research work. The community-weighted mean of trait values were calculated, and RLQ and fourth-corner analyses were performed to establish the relationship between species-traits and management practices. In addition, functional groups were extracted by means of a cluster analysis on the RLQ ordination space and the Grime’s life strategy (CSR strategy) was computed to explore possible similarities with the functional structure of the community. A total of 29 herbaceous species were selected for their highest occurrence for statistical analysis. Results indicated that tillage and mowing were the main factors conditioning the functional structure of plant communities in this study. In general, weed management significantly affected leaf economics and regenerative traits, while irrigation influenced traits related to plant size. Phenological traits emerged as a major factor in understanding the response of plant communities to weed management practices. Furthermore, up to five functional groups were identified and associated with different management practices. Functional structure of the plant communities studied was consistent with CSR strategy, which showed a strong association with agricultural management. Irrigation favoured species with a more competitive strategy. Conversely, mowing in spontaneous plant cover limited the occurrence of these competitive species. This study provides knowledge about the ecology and plant traits that could contribute to the development of more sustainable weed management.