Epsilon Archive for Student Projects

Abstract

Farms and its different management practices have substantial effects on biodiversity, with the consequent impact on the supply of certain ecosystem services such us pollination. Wild bees provide pollination services in small scale horticultural farming, which is key element to determine and improve farm production but also to the maintenance of ecosystem´s diversity. In this study we aim to identify which species of wild bees can be found in small horticultural farms in the northern area of Madrid and to analyse how its diversity is influence by agricultural practices and by the elements of the surrounding landscape. In addition, we deepen in the agricultural practices carried out in small scale horticultural production and farmer’s perception about pollination importance. By doing so, we aim to get a perspective of the agroecological transition in Madrid and the management of agroecological practices from farmer´s perspective.
To characterize the farms and to obtained information about the agricultural practices we carried out semi-structured interviews. Farmers showed awareness about the importance of pollination and wild bee communities for the development of their crops and other wild plants. Their perception on the effect of agricultural practices on pollinators match with the scientific data, being wild flowers, aromatic plants and the conservation of natural edges the practices that most influences pollinators. Farm management is rather similar within each other since all of them are small horticultural producers located in the same area. In order to quantify the differences within farms, we gave quantitative scores to the agricultural practices measuring impact and time of application.
A total of 16 horticultural farms were sample using the pan-trapping method during the flowering period of the horticultural plants to collect wild bees. Surrounding landscape composition was analysing with satellite imagery to identify the different elements present around the farms. In total, 109 wild bee species were identified with individuals from the six bee families present on the Iberian Peninsula. The most predominant genera are Lasioglossum, belonging to the Halictidae family, which are characterized by nesting in soils. The results indicated that the element with most influence on wild bee species richness is sparsely vegetated soil, followed by the presence of forest areas. These areas might correspond to potential areas of nesting sites for wild bees.
This thesis aims to contribute to better understanding of the agoecological transition in Madrid and to highlighted the importance of this small scale farming areas to promote biodiversity and landscape diversity.