Effects of Landscape Structure on Medicinal Plant Richness in Home Gardens: Evidence for the Environmental Scarcity Compensation Hypothesis

Monika Kujawska,Fernando Zamudio,Lía Montti,Veronica Piriz Carrillo

doi:10.1007/s12231-018-9417-3

Abstract

Our research involves of how Paraguayan migrants who are living in Misiones, Argentina, manage medicinal plants in home gardens, and how this practice can be related to the landscape. We examine the relationship between the richness of home garden medicinal plants and landscape variables (e.g., distance to the forest) by applying PLS analysis, which combines principal component analysis with linear regression. We surveyed 60 home gardens localized in a rural area, and we characterized the surrounding landscape with geospatial tools. Paraguayans’ home gardens are extremely diverse sites (total of 136 medicinal species), where both native (82) and introduced species (50) are managed. People who live close to the native forest or mixed use areas (e.g., farms, secondary vegetation) tend to possess less native plants in their gardens because they are available nearby. While gardeners, who live in proximity to tree crops (e.g., pine plantations), have reduced access to wild medicinal resources; therefore, their effort is concentrated on maintaining native plants. These results reflect a relationship between accessibility to medicinal plants in the landscape and the management practices in the home gardens, a neglected driver in explaining the richness and composition of the medicinal plants in home gardens so far. Thus, we contributed evidence in support of the environmental scarcity compensation hypothesis. Finally, our study supports the idea that home gardens appear to function as a springboard for plant domestication.

Highlights

IntroductionResearch indicates that factors extrinsic to the garden, such as distance to urban centers, kinship, size of family groups, forms of management, and networks of exchange, may explain the species richness and diversity of home gardens (Díaz-Reviriego et al 2016; Ellen and Platten 2011; Lamont et al 1999; Peroni et al 2016; Sander and Vandebroek 2016)
Electronic supplementary material The online version of this article contains supplementary material, which is available to authorized users.Over the last few decades, there has been a surge of home garden studies utilizing diverse methodological approaches and conceptual frameworks
In order to test the main hypotheses, we explored the relationship between the landscape variables and the richness of native and introduced species found in home gardens

Summary

Introduction

Research indicates that factors extrinsic to the garden, such as distance to urban centers, kinship, size of family groups, forms of management, and networks of exchange, may explain the species richness and diversity of home gardens (Díaz-Reviriego et al 2016; Ellen and Platten 2011; Lamont et al 1999; Peroni et al 2016; Sander and Vandebroek 2016). Studies have shown that peri-urban and urban home gardens may host a greater diversity of species than those situated in remote places. This is explained by wider opportunities for knowledge and plant exchange, especially in intercultural contexts (Bernholt et al 2009; Heckler 2007; WinklerPrins 2002). While the richness of useful tree and shrub species, mainly native ones, tends to decrease, the number of herbaceous species, especially introduced ornamental ones, increases in urban space (Poot-Pool et al 2015)

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