Long-term spatio-temporal expansion of the native-invasive Retama monosperma on coastal dunes: Importance of land-use and natural dispersal vectors

Abstract

a b s t r a c tExpansion of invasive species inducing sands stabilization is becoming an important ecological problem in coastal dunes in some parts of the world. Retama monosperma, an endemic to coasts of SE Spain and NE of Morocco, late-colonizing shrub occurring in sandy coastal areas, was planted along the coast of SW Spain during the 20th century to stabilize dunes. In recent decades, the species has spread rapidly, becoming invasive, and sometimes incurring notable changes in its environment and plant community. The expansion patterns of R. monosperma from 1956 to 2001 were described and quantified at the landscape scale within a protected dune system, using GIS. The differential effects on expansion patterns of the main factor controlling the population spread, grazing by domestic livestock and the abundance of wild rabbits, were analyzed comparatively. R. monosperma displays an exponential, invasive-type expansion trend, presenting a mean annual coverage increase of 15% and a mean lateral spread rate of 65.5 m yr −1 from the original population nucleus to the Western and Eastern ends of the study area. The dispersal activity primarily of rabbits and the absence of competing woody species contribute to this rapid expansion. The highest local increases in plant coverage could be related to increased rabbit abundance and to the improved germination rates of seeds which have passed through the rabbit gut. In contrast, areas highly grazed by livestock present the lowest increases, and an open-type plant community is maintained there for a longer time.

Morpho‐physiological response of Retama monosperma to extreme salinity levels

“…The great salt tolerance shown by R. monosperma in this experiment is likely one mechanism behind its fast expansion in El Rompido spit (Muñoz Vallés, Gallego‐Fernández, and Cambrollé ; Muñoz Vallés, Gallego Fernández, Dellafiore et al . ), where available water most of the year is a salty groundwater (Esquivias et al . , ), but it could also be the case in other sandy coastal ecosystems.…”

“…It grows on sandy soils in the proximity to the coast, on stabilized and semistabilzed dunes and marsh borders (Muñoz Vallés, Gallego Fernández, & Cambrollé, ). According to Zunzunegui, Esquivias, Oppo, and Gallego‐Fernández (), Muñoz Vallés, Gallego‐Fernández, and Cambrollé (); Muñoz Vallés, Gallego Fernández, Dellafiore, and Cambrollé () and Esquivias et al . (), R. monosperma , although a native species, behaves as an invasive one within its distribution area, in relation to its high expansion rates and to its potential for modifying environmental conditions.…”

Nutritional Characteristics and Seed Germination Improvement of the Forage Shrub Retama sphaerocarpa (L.) Boiss

“…arid ecosystems (Muñoz-Vallés et al, 2013). These species can adapt to xerophytic conditions through the strong regression of the leaf surface and a root system developed to find the water necessary for their persistence (Jiménez-Moreno et al, 2013).…”

Efeito de manchas monodominantes sobre organização e estrutura de comunidades vegetais em restinga subtropical

“…Manchas de Dalbergia que cobriam pouco mais de 10.000/m² da área de estudo passaram a ocupar 22.000/m² em 13 anos (Zocche de Souza 2010). Muitas espécies após o período de estabilização de dunas passam a expandir de maneira agressiva, tornando-se um problema para a conservação da diversidade local (Avis 1995;Muñoz-Vallés et al 2013;. Dalbergia é uma espécie frequente no litoral brasileiro (Santos & Rosário 1988;) indicada para a recuperação de áreas de dunas por seu rápido crescimento e função estabilizadora (Bechara 2004).…”