Which environmental factors affect the diversity of alien herbs in the ruderal flora in western Mexico?

Miss Isabel Pérez Postigo¹, Prof. Dr. Jörg Bendix², Dr. Heike Vibrans Lindemann³, Dr. Ramón Cuevas Guzmán¹

¹Universidad de Guadalajara, Autlán de Navarro, Mexico, ²Philipps-Universität, Marburg, Germany, ³Colegio de Postgraduados, Texcoco, Mexico

Abstract:

Disturbed areas are particularly prone to invasion by alien species. Though various hypothesis exist on the factors that influence invasive plant distribution, little is known about the relationship with environmental conditions, especially in the tropics. In Mexico, a megadiverse country, studies on invasion ecology have been restricted mainly to central Mexico and to floristic comparisons between states. In order to shed some light onto regional patterns we ask: What is the floristic composition of alien and native herbaceous species in the ruderal vegetation in western Mexico? And: Which environmental variables influence species distribution and abundance patterns of the alien and native herbaceous species?

We worked along an elevational gradient from the Jalisco state coast up to 2150 m in the Sierra de Manantlán, located in the northern part of the Southern Sierra Madre. Alien and native herb richness and abundance was documented in the field on 37 plots of 5 x 1 m² along with various environmental factors; other variables were obtained from databases. Floristic composition, species richness, abundance and their relation to the environmental variables were analysed using random forest modelling methods.

We registered 354 herbaceous species, 10% of them introduced. We found a positive correlation between native and introduced species richness but no correlation between abundances. The most important variables for alien species richness were not, as expected, measures for disturbance, but mean and maximum temperature and slope. Pattern identification helps us to understand the factors shaping present and future distributions of exotic herb species.

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Biography:

Born the 6th of june 1989 in Fürth, Germany.

Bachelor of Sciences in Physical Geography at the Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany from 2008-2011.

Bachelor thesis: Investigation of the inuence of a footpath on the natural vegetation of a tropical mountain rainforest in southern Ecuador.

Minor subjects: Biology (botany, zoology, microbiology), Earth sciences (geology, mineralogy, hydrology), Human geography

Master of Sciences in Environmental Geography: Systems, Processes and Interactions at the Philipps-Universität Marburg, Germany from 2012-2015.

Masters thesis: Potentials of remote sensing and image textures for predicting ecosystem functions in the Ecuadorian Andes

Erasmus stay at the Universidade de Lisboa, Portugal from 2013-2014 (one year).

Subjects from Physical Geography (M.Sc.) at IGOT (Instituto de Geograa e Ordenamento do

Territorio) and subjects from Ecology and Environmental management (M.Sc.), Conservation Biology (M.Sc.) at faculty of sciences.

Excursions and pratical courses (University) at different locations in Germany, Austria, Egypt, Geogria, Armenia, Ecuador, Portugal, Mexico, Guatemala and USA.

Doctorate in Sciences in Biosystematics, Ecology and Management of Natural and Agricultural Resources at Universidad de Guadalajara, Mexico since 2016.

Thesis working title: Alien species in western Mexico.