Biodiversity and pest management in orchard systems. A review

Abstract

Conventional agriculture is based on a high level of chemical inputs such as pesticides and fertilisers, leading to serious environmental impacts, health risks and loss of biodiversity in agrosystems. The reduction of pesticide use is a priority for intensively sprayed agricultural systems such as orchards. The preservation and promotion of biodiversity within orchards and their boundaries is therefore an issue to explore. Indeed, orchard systems contain high plant diversity and perennial multi-strata designs that provide wealthy resources and habitats to living communities such as beneficial organisms. Orchards thus offer favourable areas to maintain food-webs within the agrosystem, provided that favourable situations are not altered by cultural practices such as applying an excess of pesticides. Here, we analysed literature on the effects of the manipulation of plant diversity and habitats on the control of pests by arthropod and bird communities in apple, pear and peach orchards. Many investigations focus on the role of plant management to enhance biodiversity in orchards but only 22 research reports presenting 30 case studies were dedicated to the study of the ecosystem service provided by plant diversity for orchard pest control. The underlying mechanisms were seldom demonstrated, and the tested grass covers and tree assemblages aimed at favouring either the beneficial complex or only some beneficial species to control one or a few pests. The effect of plant management on pest control was mostly positive (16 cases) or null (9), but also negative in some cases (5). This finding reveals the difficulties of identifying selected plants or plant assemblages for the control of key pests. We conclude that further research is needed to identify the processes involved on different scales for biological control. Orchard systems should be redesigned to optimise ecosystem services provided by biodiversity.

The role of ecological infrastructure on beneficial arthropods in vineyards

“…In their research on dicotyledonous weeds, Wilson & Aebisher (1995) reported that the density of most arthropod species decreased significantly as distance from crop edge increased from 0 to 128 m. Some authors (Winkler, 2005;Bàrberi et al, 2010) have reviewed the importance of vegetation diversity for enhancing populations of beneficial arthropods in cropland. Wyss (1996), Simon et al (2010) and Song et al (2010) reported a positive effect of plant comunity diversification on beneficial arthropods in orchards. Non-crop habitats bordering agricultural fields in Europe have been found to have a favourable effect on a number of beneficials as spiders, ladybugs, and syrphids (Hillocks, 1998;Ernoult et al, 2013).…”

Effects of management intensity and orchard features on bird communities in winter

“…Planting orchards is a long-lasting tradition in temperate areas and they belong to perennial crops, therefore, this is a reason why orchards are regarded as a highly stable, predictable habitat for many organisms (Brown and Welker 1992;Koza´r 1992). The multi-strata design of orchards and the presence of adjacent weeds and hedges contribute to diversity of arthropods and birds (Rands 1986;Kwiatkowska 1989;Simon et al 2010). In addition, a high abundance of flowers and fruits constitute an excellent source of food for pollinating insects.…”

Ecological Footprint Applied in Agro-Ecosystems: Methods and Case Studies

“…Indeed, pests and diseases that are host-tree permanent may remain in the orchard for many years and require continuous control. Due to this effect, orchards are among the most intensively sprayed agricultural systems, in order to avoid visible and internal fruit damage and to satisfy international commercial quality standards [50]. The main environmental risks relating to the use of conventional pesticides are the negative effects on the animal and plant communities exposed both in the orchard and in the other terrestrial and aquatic ecosystems to which pesticides are lost [51].…”