Tropical ash (Fraxinus udhei) invading Andean forest remnants in Northern South America

Departamento de Ecología y Territorio, Pontificia Universidad Javeriana, Bogotá, Colombia
DOI
10.7287/peerj.preprints.3019v1
Subject Areas
Biodiversity, Conservation Biology, Ecology
Keywords
Andean forest, Demographic structure, Fraxinus uhdei, Exotic species, Plant biological invasions, Invasion pattern
Copyright
© 2017 Saavedra-Ramírez et al.
Licence
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
Cite this article
Saavedra-Ramírez KA, Etter A, Ramírez A. 2017. Tropical ash (Fraxinus udhei) invading Andean forest remnants in Northern South America. PeerJ Preprints 5:e3019v1

Abstract

Exotic invasive species represent a major driver of the loss of biological diversity and services provided by ecosystems globally. An important source of species becoming invasive are the commercial afforestation projects using fast growing and adaptable exotic species, which may become invasive impacting natural environments. The Tropical Ash (Fraxinus uhdei) native to México has been widely introduced for many decades to Colombia and other countries for timber, live fences and urban greening, is now common in many areas of the tropical mountains, and has been observed expanding into native forests in Colombia. This study explores the invasion of Tropical Ash in remnant Andean forests in Colombia, to understand the invasion pattern and the demographic structure of Tropical Ash. The analysis took into account biotic and physical factors, such as distance to the propagule source, vegetation cover types, and density of the understory and canopy cover. Although the reproductive strategy of the Tropical Ash is of “r” type with low survival rates, the results show evidence for an active process of invasion characterized by an aggregated distribution pattern. The study shows the existence of an interaction between the distance to the propagule source and the vegetation cover, which has an additive effect on the demographic structure of the population.

Author Comment

This is a submission to PeerJ for review.

Supplemental Information

Tropical Ash individuals

Shapefile with the spatial location of Tropical Ash individuals.

DOI: 10.7287/peerj.preprints.3019v1/supp-1

Tropical Ash individuals

The first column is "ID" or the identifier of each individual. The second column is "DBH" (Diameter at breast height) in centemeters. The third column is the canopy cover percentage value. The fourth column is the understory density value, measured as an ordinal variable (1 to 5, sparse to dense). The fifth column is the vegetation type (Tall forest, Low forest and Shrubland). The sixth column is "Distance_1", the distance value in the group of three ranges (0-150 m, 150-300 m and 300-600m). The seventh column is "Distance_2", the distance value in the group of two ranges (0-300 m and 300-600 m). Seedlings (DBH < 1 cm) don't have canopy cover and understory density values, because those variables were measured from juvenile state (DBH>1 cm).

DOI: 10.7287/peerj.preprints.3019v1/supp-2