Search

Simple Summary: Agricultural abandonment is a very relevant process in Europe and its consequences on biodiversity are not yet clear. Moreover, abandonment is focused on marginal areas, characterized by traditional agricultural landscapes, with high cultural and biodiversity values, which are particularly vulnerable to this process. Although increasing attention has been paid to agricultural abandonment in recent years, studies focused on traditional orchards are scarce. In our study, we analyzed how abandonment and landscape complexity (measured as the percentage of semi-natural habitats) affected three groups of beneficial arthropods (spiders, bees and hymenopteran parasitoids) in almond orchards established on the border between Spain and Portugal. Our results showed that traditional and abandoned orchards harbor different arthropod communities, with the latter favoring these beneficial arthropods in simple landscapes (with a low percentage of semi-natural habitats). However, abandoned orchards lose relevance as the percentage of semi-natural habitat in the landscape increases, highlighting the important role that these habitats play in traditional agricultural landscapes. While abandoned orchards provide valuable habitats and alternative resources, they do not substitute semi-habitats nor traditional orchards. From a conservation management perspective, both traditional almond orchards and semi-natural habitats should be conserved to protect the rich biodiversity associated with these traditional cultural landscapes. Agricultural abandonment is one of the main land-use changes in Europe, and its consequences on biodiversity are context- and taxa-dependent. While several studies have worked on this topic, few have focused on traditional orchards, especially in different landscapes and under a Mediterranean climate. In this context, we aimed to determine the effects of almond orchard abandonment on the communities of three groups of beneficial arthropods and the role of the landscape context in modulating these effects. Between February and September 2019, four samplings were carried out in twelve almond orchards (three abandoned and three traditional (active orchards under traditional agricultural management) located in simple landscapes as well as three abandoned and three traditional in complex landscapes). Abandoned and traditional almond orchards harbor different arthropod communities and diversity metrics that are strongly conditioned by seasonality. Abandoned orchards can favor pollinators and natural enemies, providing alternative resources in simple landscapes. However, the role that abandoned orchards play in simple landscapes disappears as the percentage of semi-natural habitats in the landscape increases. Our results show that landscape simplification, through the loss of semi-natural habitats, has negative consequences on arthropod biodiversity, even in traditional farming landscapes with small fields and high crop diversity. [ABSTRACT FROM AUTHOR]

Simple Summary: Olive cultivation has been extremely relevant in the Mediterranean area for centuries, creating traditional landscapes with high cultural and biodiversity values. However, in recent decades, these landscapes have been affected by two processes. On the one hand, the most productive areas have undergone significant intensification, with greater input of agrochemicals and a much higher tree density; on the other hand, marginal areas, with lower production, are being progressively abandoned. While more attention has been paid to intensification effects, few studies have considered the consequences of olive grove abandonment. In our study, we analyzed how abandonment and management regimes (organic or traditional) affected the main olive pest (Bactrocera oleae) and different groups of natural enemies in olive groves established near the border between Spain and Portugal. Our results showed that abandoned and managed olive groves had different, but similarly rich and diverse, communities of natural enemies, highlighting the complementary role that these two habitats play at the landscape scale. Moreover, abandoned groves may not be acting as a reservoir for the olive fly. To prevent land abandonment from continuing, measures such as organic farming or agritourism, which have been implemented in the studied area, could be effective. Agricultural abandonment and intensification are among the main land-use changes in Europe. Along with these processes, different proposals have been developed to counteract the negative effects derived from agricultural intensification, including organic management. In this context, we aimed to determine how organic management and farmland abandonment affect Bactrocera oleae and its main groups of natural enemies: hymenopteran parasitoids, spiders, ants, carabids, and staphylinids. Between May and October 2018, four samplings were carried out in nine olive groves (three under organic management, three under traditional management, and three abandoned) in a rural area on the border between Spain and Portugal (Salamanca, Western Spain). Our results suggested differences between the natural enemy community composition of abandoned and organic groves, with slightly higher levels of richness and abundance in abandoned groves. We found no differences between organic and traditional groves. The managed olive groves sustained a different natural enemy community but were similarly rich and diverse compared with the more complex abandoned groves, with the latter not acting as a reservoir of B. oleae in our study area. Both systems may provide complementary habitats; however, further abandonment could cause a reduction in heterogeneity at the landscape scale and, consequently, a biodiversity loss. [ABSTRACT FROM AUTHOR]