Native bamboo increases biotic resistance to Pinus contorta invasion in temperate forest ecosystems

Abstract

One of the tree species with the greatest invasive potential worldwide is Pinus contorta Douglas ex Loundon, which is characterized by producing a great number of individuals in short periods of time, generating different impacts on the ecosystems it invades. The genus Chusquea is present in a diverse number of ecosystems in South America. In the temperate forests of Chile and Argentina, it forms dense thickets in the undergrowth as well as in open areas. Its rapid growth and vegetative reproduction, with large numbers of individuals, allow the species to dominate and restrict the establishment of other plant species. This study focused on analyzing the effect of the presence of individuals of Chusquea culeou E. Desv. on the establishment of the invasive species Pinus contorta, as well as on other native herbaceous and shrub species in Araucaria-Nothofagus forest. With this aim, we established 204 plots within the Malalcahuello National Reserve (in the Andes of south-central Chile) along a gradient of P. contorta invasion, where the presence or absence of these species was recorded through different percentages of Chusquea cover. The results showed that the probability of presence of P. contorta decreases significantly in areas where Chusquea cover is greater than 25%. Native species also decrease their presence, but to a lesser extent compared to P. contorta. Our results demonstrate the inhibitory effect of Chusquea for the establishment of other plant species, but more markedly for invasive conifers.

The enemy of my enemy… Exotic mammals present biotic resistance against invasive alien conifers

“…We found that prevents new species establishing, or due to negative interactions with existing species in the community (Byers and Noonburg 2003;Gioria et al 2023). Where available niche space exists, biotic resistance can prevent or slow establishment of new species through competition for resources or via direct predation from resident animals (Levine et al 2004;Ulloa et al 2023). Herbivory has been shown to be equivalent to the effects of competition in resisting invasive plant encroachment (Levine et al 2004;Santamaría et al 2021), and similarly granivory (seed predation) is seen as a major pathway of biotic resistance (Lopez and Terborgh 2007;Pearson et al 2011Pearson et al , 2012Preukschas et al 2014;Moyano et al 2019b;Muschetto et al 2022).…”

The enemy of my enemy... Exotic mammals present biotic resistance against invasive alien conifers

“…Biotic resistance, where existing species resist the establishment of new or invasive species into their community (Levine et al 2004;Beaury et al 2020), represents a major pathway for the prevention of wilding conifer establishment. While this can be expressed through competition for resources (Ulloa et al 2023), seed predation is a major contributor to biotic resistance of invasive plant species (Pearson et al 2011;Preukschas et al 2014;Moyano et al 2019a;Muschetto et al 2022). Aotearoa New Zealand hosts many granivorous species, both native and introduced, which could contribute to biotic resistance pressures against wilding conifers via seed predation (Thorsen et al 2009;Thorsen et al 2011;Walker et al 2019).…”