A nurse plant benefits from facilitative interactions through mycorrhizae

Abstract

Plant facilitation promotes coexistence by maintaining differences in the regeneration niche because some nurse species recruit under arid conditions, whereas facilitated species recruit under more mesic conditions. In one Mexican community, 95% of species recruit through facilitation; Mimosa luisana being a keystone nurse for many of them. M. luisana individuals manifest greater fitness when growing in association with their facilitated plants than when growing in isolation. This observation suggests that nurses also benefit from their facilitated plants, a benefit thought to be mediated by mycorrhizal fungi.• Under field conditions, we experimentally tested whether mycorrhizal fungi mediate the increased fitness that M. luisana experiences when growing in association with its facilitated plants. We applied fungicide to the soil for nurse plants growing alone and growing in association with their facilitated plants in order to reduce the mycorrhizal colonisation of roots. We then assessed the quantity and quality of seed production of M. luisana in four treatments (isolated-control, isolated-fungicide, associated-control and associated-fungicide).• Fungicide application reduced the percentage root length colonised by mycorrhizae and reduced fitness of M. luisana when growing in association with their facilitated plants but not when growing in isolation. This reduction was reflected in the total number of seeds, number of seeds per pod, seed mass and seed viability.• These results suggest that nurses benefit from the presence of their facilitated plants through links established by mycorrhizae, indicating that both plants and belowground mutualistic communities are all part of one system, coexisting by means of intrinsically linked interactions.

Phenotypic structure of plant facilitation networks

“…But, again, despite the rationale was that persistent interactions would be those involving the most functionally different species, phenotypically informed networks have never been used to test this hypothesis. Increasing evidence on the permanence of interactions between functionally different species exist (Navarro‐Cano et al ., 2019), and explanations have invoked not only the conventional wisdom of competition reduction but also mutual help between species (Sortibrán et al ., 2014, 2019; Montesinos‐Navarro et al ., 2016, 2017). These new results open a research avenue to search for functional traits that could be putatively involved in the maintenance of facilitation networks with time.…”

Effect of brousse tigrée on the dynamics of nurse–protégé interactions of a cactus in the Chihuahuan Desert

“…Direct effects such as the buffering of extreme environmental conditions, are the most commonly addressed in nurse-protégé studies. However, indirect effects such as the reduction of herbivory in the protégé species or introduction of beneficial organisms such as mycorrhizae are less frequently studied, even though both types of effects may be occurring simultaneously (Callaway, 1995;Callaway, 2007;Mandujano et al, 1998;Sortibrán et al, 2019). In the case of E. enneacanthus, the reduction of the intensity of environmental conditions (mainly extreme temperatures and high solar radiation) may be one of the direct effects they receive from their nurse plants.…”

“…Interestingly, cases of mutualism also occur when the shrub Mimosa luisana acts as a nurse plant to the columnar cactus Neobuxbaumia tetetzo . Initially, the nurse is needed for the establishment of the cactus, but when the protégé grows, it transfers water, stored in its stem, to the nurse through soil mycorrhizae (Montecinos‐Navarro, Verdú, Querejeta, & Valiente‐Banuet, 2019; Sortibrán et al, 2019; Valiente‐Banuet et al, 1991). Positive and negative interactions between nurse and protégé may occur simultaneously or at different times during the life cycle, and the net effect on the recently established or adult protégé plants depends on their tolerance to the environment in which the interactions are occurring (Franco & Nobel, 1989; Holmgren et al, 1997).…”

The First Reported Case of Bullous Lichen Planus/Systemic Lupus Erythematosus Overlap Syndrome

“…Similarly, vesicle colonization reduced after fungicide application of 66% and 88% in isolated and associated M.cuisana. The fungicide reduces the total number of seeds, seeds per pod, seed mass, and seed viability [29].…”