Comparison of two Mediterranean crop systems: Polycrop favours trap-nesting solitary bees over monocrop

• Published in: Basic and applied ecology 2013-05, Vol.14 (3), p.255-262
• Main Authors: Baños-Picón, Laura, Torres, Félix, Tormos, José, Gayubo, Severiano F., Asís, Josep D.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Brood cells; Cereal; community structure; continuous cropping; Emergent progeny; Farming intensity; farming systems; Fundamental and applied biological sciences. Psychology; General agroecology; General agroecology. Agricultural and farming systems. Agricultural development. Rural area planning. Landscaping; General agronomy. Plant production; Generalities. Agricultural and farming systems. Agricultural development; habitats; landscapes; Mixed vegetable crop; Osmia; progeny; solitary bees; space and time; species diversity; Species richness; vegetable crops; Vineyard; vineyards
• ISSN: 1439-1791
• DOI: 10.1016/j.baae.2012.12.008

Landscape, in terms of crop diversity, together with spatial heterogeneity, connectivity and the proportion of natural elements all play a key role in the quality of the agricultural matrix. The abundant resources derived from the high productivity associated with cultivated lands within agricultural landscapes – formed by mosaics comprising small elements and systems of low agricultural intensity – may favour the populations and communities of certain insect species. Here, trap-nesting solitary bees have been studied to evaluate the effect of two Mediterranean crop systems: monocrops (vineyard and cereal) and polycrops (mixed vegetable crop) for two levels of farming intensity (high-intensity vs. low-intensity) on brood cells and emergent progeny of the bee population and community species richness. Polycrops proved favourable compared to monocrops, with the former proving particularly favourable for offspring production (brood cells and emergent progeny) of bees belonging to the genus Osmia. Bee populations, especially polylectic species, may benefit from the traits characterizing this polycrop, which provide plentiful and diverse resources both in space and time. Farming intensity, regardless the crop type, is also an important factor affecting bee community structure. Low farming intensity maintains essential semi-natural habitats providing shelter for species-rich communities. Crop richness, together with low farming intensity would provide heterogeneous landscapes with a variety of natural and cultivated resources, benefitting trap-nesting bee populations. Für die Qualität der landwirtschaftlichen Matrix spielt die Landschaft eine Schlüsselrolle in Form von Feldfruchtdiversität zusammen mit der räumlichen Heterogenität, Vernetzung und den Anteilen der naturnahen Elemente. Die Häufigkeit der Ressourcen, die aus der hohen Produktivität des kultivierten Landes in Agrarlandschaften folgt, die durch Mosaike von kleinen Elementen und Systemen mit geringer landwirtschaftlicher Intensität geprägt sind, könnte die Populationen und Gemeinschaften bestimmter Insektenarten fördern. Wir untersuchten Solitärbienen in Nisthilfen, um den Effekt von zwei mediterranen Anbausystemen auf die Brutzellen und die geschlüpften Nachkommen von Bienenpopulationen und den Artenreichtum der Bienengemeinschaft zu evaluieren: Monokulturen (Weinberge und Getreide) und Polykulturen (gemischter Gemüseanbau) in zwei Bewirtschaftungsintensitäten (hohe Intensität vs. geringe Intensität)