Effects of Landscape Structure on Medicinal Plant Richness in Home Gardens: Evidence for the Environmental Scarcity Compensation Hypothesis
Effects of Landscape Structure on Medicinal Plant Richness in Home Gardens: Evidence for the Environmental Scarcity Compensation Hypothesis
VERONICA PIRIZ CARRILLO
MONIKA KUJAWSKA 2
FERNANDO ZAMUDIO 1
LÍA MONTTI 3
0 Instituto de Investigaciones Marinas y Costeras, UNMdP-CONICET & Instituto de Geología de Costas y del Cuaternario , UNMdP-CIC, Deán Funes 3350-CP 722, Buenos Aires , Argentina
1 Interacciones ecológicas y conservación, Instituto Multidisciplinario de Biología Vegetal (CONICET- UNC) , Av. Vélez Sarsfield 299, 5000, Córdoba , Argentina
2 Institute of Ethnology and Cultural Anthropology, University of Lodz , ul. Lindleya 3/5, 90-131, Lodz , Poland
3 Tucuman , Argentina
4 Instituto de Biología Subtropical, UNaM-CONICET , Bertoni 85, CP 3370, Puerto Iguazú, Misiones , Argentina
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.
Agrobiodiversity; Domestication; Ethnobotany; Geospatial tools; Land use; Migrants; Paraguayan farmers; Plant management; Atlantic Forest
Introduction
Over the last few decades, there has been a surge
of home garden studies utilizing diverse
methodological approaches and conceptual frameworks.
Scholars have formulated questions related to plant
use, richness, diversity, composition, and structure
within these social-productive units
(Padoch and de
[VOL
Jong 1991; Parihaar et al. 2014; Smith et al. 2006;
Sujarwo and Caneva 2015)
. It has been
acknowledged that both intrinsic and extrinsic factors affect
the richness of species in home gardens. Common
intrinsic factors are, for example, the size of the
garden, its age, and its proximity to the dwelling,
among others
(Blanckaert et al. 2004; Coomes and
Ban 2004; Sander and Vandebroek 2016)
. On the
other hand, 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)
. For example,
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)
. More recent studies, however, have
demonstrated that biodiversity in home gardens
differentiates along the rural-peri-urban gradient, without
necessarily increasing or declining (Peroni et al.
2016; Poot-Pool et al. 2015). 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).
Home gardens are one of the oldest forms of land
use
(Kumar and Nair 2004)
. They represent
reservoirs of currently cultivated and potentially useful
resources (Alvarez-Buylla et al. 1989), and provide a
wide range of ecosystem services (Calvet-Mir et al.
2012). Importantly, there is a considerable
consensus in favor of acknowledging rural and urban
gardeners for their in situ preservation of biological and
genetic diversity
(Galuzzi et al. 2010; Heraty and
Ellstrand 2016; Kumar and Nair 2006; Saleko et al.
2014)
. Moreover, home gardens are suitable places
for the study of gardeners’ choices concerning the
selection of plant species for pro (...truncated)