An integrated model to study varietal diversity in traditional agroecosystems.

Vitor Hirata Sanches,Fernando Fagundes Ferreira,Cristina Adams,Abid Hussain

doi:10.1371/journal.pone.0263064

Abstract

Agricultural diversity is one of the bases of traditional agroecosystems, having great environmental and cultural importance. The current loss of agricultural diversity is causing serious concern, mainly because of its essential role in supporting global and local food security. Stopping this loss requires a better understanding of how diversity is managed locally and what mechanisms sustain agricultural diversity. Here we propose a generalist agent-based model that couples biological, cultural, and social dynamics to obtain varietal diversity as an emergent phenomenon at the community level. With a mechanistic approach, we explore how four of the model dynamics can shape systems diversity. To validate the model, we performed a bibliographic review on Manihot esculenta and Zea mays case studies. The model yielded compatible results for manioc and maize varietal richness at both community and household levels.

Highlights

The livelihoods of traditional and indigenous communities around the world are facing rapid changes, including the loss of agricultural diversity [1,2,3]
The academic and development literature have given increasing attention to this fact due to its impact on food security and genetic diversity, which are crucial in a world facing climate change [1,2,3,4]
Agrobiodiversity is a broad term that incorporates all components of biodiversity relevant to agroecosystems, helping to sustain their key functions, structure, and processes [5]. These components include the variety and variability of animals, plants, and microorganisms at the genetic, species, and ecosystem levels [5]. This type of diversity results from interactions between genetic resources, the environment, and the culturally diverse practices and management systems adopted by people in socioecological systems [6]

Summary

Introduction

The livelihoods of traditional and indigenous communities around the world are facing rapid changes, including the loss of agricultural diversity [1,2,3]. Answering this generative question [32] can improve understanding of the origins of varietal diversity and the social and biological dynamics that create and sustain it To address this question, we developed a multilevel agent-based model that integrates plot (or farm), household, and community levels to study varietal diversity. An integrated model to study varietal diversity in traditional agroecosystems a way to illuminate the core dynamics of a system, understand emergent behavior, and help theory building in early stages of a particular problem [33, 34], contributing to the development of more realistic models in the future. [36] analyze the effect of different network topologies on the diffusion and persistence of introduced varieties These models were applied to case studies and uncover important knowledge on the role of the seed exchange network. Historical diffusion of maize out of the Americas led to the selection of hundreds of new varieties in the past 500 years [51]

Materials and methods

Results

Findings

Discussion