Monitoring within non-native ungulate exclosures documents the inherent size of Crocanthemum greenei (Cistaceae)

By

Dvorak, Tyler
Catalano, Amy
Guilliams, C. Matt

Type

Article

Date of Publication

2016

Original Publication

PhytoKeys

Volume

70

Pages

11-16

Subjects

Cistaceae , Crocanthemum greenei , Helianthemum , Santa Catalina Island , stem measurement

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Pensoft Publishers [2010]-

Identifiers

DOI: https://doi.org/10.3897/phytokeys.70.9363

 

Abstract

Crocanthemum greenei (B.L.Rob.) Sorrie (Cistaceae), a perennial sub-shrub, was measured as part of a demographic monitoring effort on Santa Catalina Island, California, USA (hereafter, Catalina). Introduced ungulate browsers remain present on Catalina. Consequently, many palatable plant taxa on the island are subject to and putatively limited by top-down browsing forces. Historically, introduced ungulates have also been present on each island throughout the range of C. greenei. Habitat conservation work, resulting in the construction of ungulate exclosures on Catalina, has now allowed us to measure individuals in their mature, non-browsed form. The published value for C. greenei stem (height) is usually 15–30 cm. While the original description hints at a greater potential size, recent descriptions appear to be influenced by observations made during the decades when plants would have been impacted by introduced ungulate herbivores. Here we present stem measurements of 81 adult individuals, with a median of 49 cm and an interquartile range of 42–56 cm. These measurements suggest an expanded stem (height) range of 15–60 cm better describes the taxon and shed light on the historical impacts of invasive ungulates across the islands and those continuing on Catalina.