The role of phytochemical diversity in the management of agroecosystems

Abstract

Biodiversity in ecosystems is crucial in providing ecosystem services and their stability and resilience. However, most studies supporting the benefits of biodiversity in crop health were studied at the cultivar scale, generally without specifying the resistance mechanisms involved in the resistance of crops to pests. Thus, it is unclear if phytochemical diversity is one of those resistance mechanisms and whether the ecosystem patterns and processes in which phytochemical diversity is involved can be replicated or adapted to the management of sustainable agroecosystems. Here, I review the roles of phytochemical diversity in natural ecosystems and determine if they can be helpful in the management of agroecosystems. I briefly review (a) the spatial and temporal structure of phytochemical diversity in ecosystems and its effect on plant consumers; (b) how that diversity is generated and maintained; and (c) the current or potential role of phytochemical diversity in agroecosystems. The α-, β-, and γ-phytochemical diversities are very high in ecosystems and landscapes; phytochemical diversity gets displayed in dynamic mosaics of mixtures of secondary metabolites that vary in their concentration and composition within and among individuals, populations, or species. Phytochemical diversity is fostered by evolutionary or coevolutionary processes, mainly under an arms-race scenario. The patterns and processes of phytochemical diversity are idiosyncratic depending on the identity of the interacting species and the local biotic and abiotic environment; thus, to copy them to industrial agroecosystems is hardly viable. However, five recommendations in which phytochemical diversity could be helpful in agroecosystem management are made.

Understanding the phytochemical diversity of plants: Quantification, variation and ecological function

“…Finally, although most research so far has aimed to answer fundamental ecological questions, a few studies have been done in a more applied context, examining phytochemical diversity for crop species, and its potential importance for protection against pest insects (Whitehead and Poveda 2019, Espinosa-García et al 2021, Robinson et al 2022, Bernal et al 2023). Further research on this topic could increase our understanding of how considerations of chemodiversity could be utilized in agroecosystems (Silva et al 2018, Espinosa-García 2022).…”

Bringing Fundamental Insights of Induced Resistance to Agricultural Management of Herbivore Pests

“…Even in monocultures with high genetic uniformity, induced resistance may reduce the potential of natural enemies to adapt to resistance traits. Enhancing crop genetic or species diversity will create an even more diverse patchwork of defence mechanisms that will further strengthen the resistance of cropping systems to counteradaptations by herbivores (Espinosa-Garcia 2022 ).…”

Increasing intraspecific plant chemical diversity at plot and plant level affects herbivorous, predatory, and pollinating arthropod communities

“…Biodiversity is recognized as a driver of ecosystem functioning and stability (Mora et al, 2014;Espinosa-García, 2022). Biodiversity studies have focused on species richness, examining how increasing plant community diversity affects ecosystem-level processes (Schulze & Mooney, 1992;Cardinale et al, 2006;Eisenhauer et al, 2011;.…”

“…Larger-scale studies in chemodiversity are scarce and predominantly correlative. Studies have examined how local chemotype richness influences arthropod communities (Hauri et al, 2021;Espinosa-García, 2022), but questions remain on the responses of different arthropod groups. Manipulative experiments, directly testing the consequences of a gradient of chemotype richness at the group level, show that increasing chemodiversity correlates with higher herbivore diversity but lower plant damage (Bustos-Segura et al, 2017).…”