Differences in the insect fauna associated to a monocultural pasture and a silvopasture in Southeastern Brazil

Abstract

A major challenge for global agriculture is the reduction of the environmental impacts caused by meat and dairy production, and the conversion of monocultural pastures to silvopastoral systems has emerged as an important ally in this process. In order to understand the effects of this conversion we analysed 4 years of sampling of the insect fauna from a conventional monocultural pasture and a silvopastoral system in Minas Gerais, Brazil. We aimed to determine whether the changes caused by the conversion affected the abundance, richness and diversity of the insect orders found in the two systems. Total abundance, richness and diversity did not differ between the two systems, but we detected a significant difference in community composition. Several insect orders showed differences in either abundance, richness or diversity between the two systems, and several families of Hymenoptera, which contains pollinators and natural enemies, showed important increases in the silvopasture. Conversion of monocultural pastures to silvopastures can have important consequences on insect fauna involved in essential ecosystem functions, and the implementation of silvopastures at larger scales has the potential to benefit biodiversity conservation and ecosystem service provision at the landscape scale. Bovine livestock is one of the most important sectors of Brazilian agribusiness, and consequently of Brazil's national economy 1. Over 80% of the herd depends on pastures as its major source of food. Pastures are a practical and economically efficient form of producing and offering food to cattle, since they are resistant to fluctuations in grain prices, guaranteeing relatively low costs of production 2,3. An important characteristic of the dynamics of Brazilian pastures has been the substitution of native pastures, composed of native grassland ecosystems in the Cerrado and Pampas, with pastures sown with exotic grass species, especially from the genus Brachiaria, which currently constitute over 50% Brazilian pastures 2. Intensive management of agricultural ecosystems and inappropriate pasture management, such as a lack of nutrient addition, result in the simplification of biological communities, and are the main cause of pasture degradation 4,5. In the search for production systems that minimise the effects of land degradation and increase the profit obtained by farmers, agroforests have emerged as an important alternative 6. Agroforests are increasingly used in Latin America to enhance biodiversity and the provision of ecosystem services. The adoption of agroforests in pastures, in the form of silvopastoral systems, creates an environment that buffers temperature extremes and is more comfortable for the animals, reduces erosion from runoff and wind and increases soil biomass, thus contributing to nutrient cycling 7. Furthermore, combining pastures with trees creates a diversity of microclimates that increases insect diversity 8. The effect of conversion to silvopastoral systems on specific insect groups has been studied previously 9...

Influence of scattered trees in grazing areas on soil properties in the Piedmont region of the Colombian Amazon

“…These data are consistent with those obtained by Durán et al [ 61 ] and Rodríguez et al [ 12 ] who carried out their sampling without considering the effect of the influence of the tree canopy on pastures that are in a certain state of degradation. Therefore, increasing the levels of shade in pastures improves different ecosystem services [ 26 , 62 , 63 ] related mainly to the contribution of biomass [ 64 ] (quantity and chemical composition), microclimatic conditions [ 62 , 65 ] (humidity and temperature) that affect the richness and density of the soil macrofauna community [ 66 ]. In this sense, increasing the density of trees in pastures specifically in silvopastoral systems increases macrofauna populations [ 64 , 67 ].…”

Faunistic analysis of insects of Deva Vatala National Park and agroecosystem of Gujrat Pakistan

“…We used a paired analysis, where our samples were paired by month between two sites. We did not consider the samples for the analysis when the corresponding pair was not observed at any of the sites in order not to unbalance the analysis for insect species (Paiva et al 2020). We also performed the similarity of percentages analysis (SIMPER) to identify the species contributing most to differences in communities across space and time.…”

“…One set of pan-trap consists of three pans, one in each colour placed at the same height (Berglund 2016). Data collected from traps after 15 days constituting a single sample (Paiva et al 2020).…”

“…of each taxon (order level, family, genera, and species) were used to identify the specimens (Mouhoubi et al 2019). The insects were preserved in 70% alcohol and the specimens were separated into different orders and families and identified as morphospecies (Paiva et al 2020).…”

Promoting Forage Legume–Pollinator Interactions: Integrating Crop Pollination Management, Native Beekeeping and Silvopastoral Systems in Tropical Latin America

“…At a landscape level, they provide more ecosystem services than open pastures (Calle et al, 2009;Murgueitio et al, 2011). In Brazil, the conversion from pasture monocultures to SPS has increased the abundance, richness and diversity of insects, including pollinators (Auad et al, 2015;Paiva et al, 2020).…”