Plants used for hedging in Patagonian cities: an ethnobotanical contribution to conservation

Abstract

Hedges constitute a significant part of Patagonian city landscapes, and can be very important not only as reservoirs of biodiversity, but also as possible sources of invasion. In this work, carried out in eight Patagonian tourist cities, species richness was estimated and the botanical families and biogeographical origin of the plants chosen for hedges were recorded. Considering the influence of European colonists on cultural and landscaping development in the region, one would expect a high proportion of resources to be of Holarctic origin. Species were identified in 100 homes chosen at random in each locality (San Martín de los Andes, Villa la Angostura, Dina Huapi, El Bolsón, Lago Puelo, Esquel and Trevelin) and in 300 homes in Bariloche, due to its greater size. Total plant richness was 137 species, the most common being Cytisus scoparius (L.) Link (9%), Rosa sp. (8%), Pseudotsuga menziesii (Mirb.) Franco (7%), Cupressus macrocarpa Hartw. ex Gordon (5%) and Ligustrum sinense Lour. (3%). Of the 48 botanical families represented, the most frequent were Rosaceae, Fabaceae, Cupressaceae and Pinaceae (67% of the total registered). Species come from the following regions: Holarctic (72%), Antarctic (23%), Paleotropical (19%), Neotropical (5%) and Australian (2%). We conclude that the hedges studied, in terms of species richness, display similarities with the main ornamental species at a global level. However, the presence of Antarctic elements (32 species) indicates the incorporation of species native to Andean-Patagonian forests, and therefore an important role is being played here in terms of conservation. In addition, our survey shows that certain species may present a risk of biological invasion (e.g., Sorbus aucuparia L., Crataegus monogyna Jacq., Ulex europaeus L.) and we therefore propose that the population should be warned about the negative effects of these species.