Markedly declining reproductive functional diversity of food plants in the world's largest tropical country despite rapid cropland expansion

Cropland intensification in tropical regions is usually associated with agricultural commodity expansion that penalizes the species diversity and environmental services of natural ecosystems. However, the extent to which cropland expansion affects the reproductive functional diversity of crop arrangements remains poorly investigated. Here we examine the agricultural development of a leading agricultural producer and megadiverse country (Brazil) over the last six decades to understand the effects of agricultural expansion on the reproductive functional diversity of crops, particularly those bearing specialized traits. We used the FAO database, which provides annualized information on crop production from 1961 to 2018. Cultivated species were classified according to their reproductive traits and levels of dependence on biotic pollination, used as indicators of functional diversity. Our results show that cropland areas in Brazil expanded by 201.3% from 1961 to 2018. In particular, pollinator-dependent crops expanded over this period by 305.2% compared to 125.3% in non-dependent crops. Expansion of monoculture farmland was remarkable, comprising 88% of the entire agricultural cropland acreage in 2018, 45% of which was represented by soybean. Additionally, cropland expansion was related to a reduction in functionally diverse crop species, which was most intense for those with specialized reproductive traits. These results indicate a threat to a diversified food production system and its resilience, given the impacts of cropland expansion on native biodiversity and the reduction in pollination services for many crops. We argue that agroecosystems in Brazil require sustainable, pollinator-friendly agricultural practices to maintain or enhance a nutritionally diversified food production system. Integrated practices that sustain agricultural cropland mosaics characterized by high reproductive functional diversity of the cultivated species can be a nature-based solution to protect natural pollinators and pollination services within a diversified food system.

Automated summary

This study investigates the impact of cropland expansion in Brazil on the reproductive functional diversity of crops. The results show that cropland expansion has led to a reduction in functional diversity, particularly for crops with specialized reproductive traits. This poses a threat to the diversity and stability of both the food production system and the ecosystem. Therefore, sustainable and pollinator-friendly agricultural practices are needed to protect natural pollinators and ensure a diversified food system.