Quantifying errors and omissions in alien species lists: The introduction status of Melaleuca species in South Africa as a case study

By

Jacobs, Llewellyn E.O.
Richardson, David
Lepschi, Brendan Johann 1969-
Wilson, John

Type

Article

Date of Publication

2017

Original Publication

NeoBiota : advancing research on alien species and biological invasions

Volume

32

Pages

89-105

Subjects

Biological invasions , Callistemon , herbarium specimen , invasive species listing , Myrtaceae , tree invasions

Contributed by

Pensoft Publishers

Language

English

Published by

Sophia, Bulgaria Pensoft Publishers

Identifiers

DOI: https://doi.org/10.3897/neobiota.32.9842

 

Abstract

Introduced species lists provide essential background information for biological invasions research and management. The compilation of these lists is, however, prone to a variety of errors. We highlight the frequency and consequences of such errors using introduced Melaleuca (sensu lato, including Callistemon) species in South Africa as a case study. We examined 111 herbarium specimens from South Africa and noted the categories and sub-categories of errors that occurred in identification. We also used information from herbarium specimens and distribution data collected in the field to determine whether a species was introduced, naturalized and invasive. We found that 72% of the specimens were not named correctly. These were due to human error (70%) (misidentification, and improved identifications) and species identification problems (30%) (synonyms arising from inclusion of Callistemon, and unresolved taxonomy). At least 36 Melaleuca species have been introduced to South Africa, and field observations indicate that ten of these have naturalized, including five that are invasive. While most of the errors likely have negligible impact on management, we highlight one case where incorrect identification lead to an inappropriate management approach and some instances of errors in published lists. Invasive species lists need to be carefully reviewed to minimise errors, and herbarium specimens supported by DNA identification are required where identification using morphological features is particularly challenging.