Testing alien plant distribution and habitat invasibility in mountain ecosystems: growth form matters.
GIORGIS, MELISA A.; CINGOLANI, ANA MARÍA; TECCO, PAULA A.; CABIDO, MARCELO; POCA, MARÍA; VON WEHRDEN, HENRIK
Lugar: Berlin; Año: 2016
Most studies focused on understandinghabitat invasibility use the current levels of invasion asa direct proxy of habitat invasibility. This has shown tobe biased by the influence of propagule pressure andclimate. We suggest that plant growth forms need to beconsidered as an extra factor, as habitat preferencesmight not be equal for all potential invaders. We testthe influence of propagule pressure, climate andhabitat characteristics on the current level of invasionand habitat invasibility, specifically addressingwhether an analysis focused on growth forms evidence different patterns than the total pool of alien species.We used 499 floristic vegetation plots located inCo´rdoba Mountains. We used proportional alienrichness of the total pool and for each growth formas response variables. We identified models that bestexplained current levels of invasion. We used theresiduals of the models with propagule pressure andclimate as the response variable. Then, we performedlinear models to test the relationship between habitatcharacteristics and the residuals of the models. Wefound different drivers of current alien distributionpatterns for the total pool and each growth form.Habitat invasibility was not equal when quantified forthe total pool or growth forms. Shrublands andoutcrops were recorded as less susceptible to woodyinvasion, while grasslands and native woodlands wereresistant to the invasion of grasses and none habitattype was resistant to the invasion of forbs. Wehighlight that the current level of invasion and habitatinvasibility are highly growth form dependent.