Life history variation and demography of the invasive plant Eschscholzia californica Cham. (Papaveraceae), in two altitudinal extremes, Central Chile

Abstract

In this study, we compared demographic responses of Eschscholzia californica populations located at different altitude, under the basic assumption that altitudinal gradients impose environmental limitation to the spread at the upper edge of the gradient. We detected significant differences among populations either in terms of life history attributes and the finite rate of increase. In general, coastal population expressed higher finite population rates than mountain populations, although these differences were not statistically significant. Mountain populations (Corral Quemado and Farellones) expressed a finite population rate not significant different of 1. These result suggest that at the upper front of invasion the species is in a demographic equilibrium because in spite of we detected a higher plant fecundity, there exist ecological constraints a seed stage level. We proposed to address more specific studies assessing from one hand, seed movement from lower altitudes and the efficiency of domestic cattle as biotic vector; we also propose to examine the feasibility of this species to establish positive interactions with cushion plants, and therefore to expand its geographic range due to this facilitation effect. KEYWORDS:Populations, invasions, heterogeneity, demographic matrix. RESUMENEn este estudio comparamos las respuestas demográficas de las poblaciones de Eschscholzia californica ubicadas a diferentes altitudes, bajo el supuesto básico de que los gradientes altitudinales imponen limitaciones a la invasión. Se detectaron diferencias significativas entre las poblaciones, ya sea en términos de atributos de la historia de vida y tasa finita de crecimiento. En general, las poblaciones costeras expresaron mayores tasas de crecimiento que las poblaciones de montaña, aun cuando éstas no fueron estadísticamente significativas. Las poblaciones de montaña (Corral Quemado y Farellones) fueron las únicas que mostraron una tasa de crecimiento similar a 1. Estos resultados sugieren que las poblaciones ubicadas en el frente superior de invasión estarían en un equilibrio demográfico debido a que aun cuando se detectó una elevada fecundidad, existen restricciones ecológicas a nivel de las semillas. Proponemos hacer estudios más específicos para evaluar un posible movimiento de semillas desde altitudes más bajas y la eficiencia del ganado doméstico como vector transportador de estas semillas; proponemos también examinar la posibilidad que tiene esta planta de establecer interacciones positivas con las plantas en cojín, ubicadas a mayores alturas y, por lo tanto, ampliar su rango altitudinal debido a este efecto de facilitación.

Climatic Niche Conservatism and Biogeographical Non-Equilibrium in Eschscholzia californica (Papaveraceae), an Invasive Plant in the Chilean Mediterranean Region

“…In 1890, the first specimen from a naturalized population was collected near Valparaíso (coastal central Chile). This species is currently distributed in Chile between latitudes 30° and 38° S, and between 0 and 2,200 m altitude [30] , [31] . E. californica is particularly interesting for studying the niche dynamics because plant size, fecundity, and resistance to herbivores are significantly greater in the invaded range (central Chile) than in the native one [32] – [34] .…”

Microbial communities of bulk and eschscholzia californica rhizosphere soils at two altitudes in Central Chile

“…UV radiation (Rinnan et al, 2006), temperature (Kuzyakov et al, 2007), or soil moisture (Reid, 1974). However, differences in some plant features, mainly floral and vegetative characters, have been observed among E. california populations located at different altitudes in the same sampling area of our study (Peña-Gómez and Bustamante, 2012). Some differences of these phenotypic traits related with a decrease in reproductive effort (biomass/flower size and flower number) would suggest that populations at higher altitude could have limitations in obtaining resources (Hiraga and Sakai, 2007) and this stress condition could indirectly affect rhizosphere microbial assemblages.…”

“…(Arroyo et al, 2000). Even though E. californica is a very common plant in California and Chile, studies conducted to address its ecology are relatively scarce and particularly reported significant differences in reproductive and vegetative characteristics among E. californica populations located at different altitudes in Central Chile (Peña-Gómez and Bustamante, 2012;Castillo et al, 2013).…”

Accounting for stochasticity in demographic compensation along the elevational range of an alpine plant

“…While many studies have uncovered elevational patterns in plant life history across species, studies on population dynamics are less common, and patterns of variation in plant population growth rates along elevational gradients are less clear. Indeed, the few studies focusing on dynamics of herbaceous plant populations on elevational gradients report increasing (Miller et al 2009; Giménez‐Benavides et al 2011), decreasing (Kim & Donohue 2011; Pena‐Gomez & Bustamante 2012) and stable (García‐Camacho et al 2012) patterns of population growth rates with elevation.…”