Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Accueil du site → Master → Etats Unis → 2011 → Effects Of Saltcedar On Population Structure and Habitat Utilization of the Common Side-Blotched Lizard

Arizona State University (2011)

Effects Of Saltcedar On Population Structure and Habitat Utilization of the Common Side-Blotched Lizard

Nielsen, Danny Patrick

Titre : Effects Of Saltcedar On Population Structure and Habitat Utilization of the Common Side-Blotched Lizard

Auteur : Nielsen, Danny Patrick

Université de soutenance : Arizona State University

Grade : M.S. Applied Biological Sciences 2011

Résumé
Non-native saltcedar (Tamarix spp.) has invaded many riparian communities and is the third most abundant tree in Southwestern riparian areas. I evaluated lizard populations and microhabitat selection during 2009 and 2010 along the Virgin River in Nevada and Arizona to determine the impact of saltcedar. Along the riparian corridor, I observed common side-blotched lizards (Uta stansburiana) within two vegetation types : monotypic non-native saltcedar stands or mixed stands of cottonwood (Populus fremontii), willow (Salix spp.), mesquite (Prosopis spp.) and saltcedar. I predicted that population parameters such as body condition, adult to hatchling ratio, abundance, and persistence would vary among vegetation types. Also, I predicted the presence of saltcedar influences how lizards utilize available habitat. Lizard population parameters were obtained from a mark-recapture study in which I captured 233 individual lizards. I examined habitat selection and habitat availability using visual encounter surveys (VES) for lizards and recorded 11 microhabitat variables where 16 lizards were found. I found no significant difference in population parameters between mixed and non-native saltcedar communities. However, population parameters were negatively correlated with canopy cover. I found that lizards selected habitat with low understory and canopy cover regardless of vegetation type. My results indicate that lizards utilize similar structural characteristics in both mixed and non-native vegetation. Understanding impacts of saltcedar on native fauna is important for managers who are tasked with control and management of this non-native species.

Mots Clés : Ecology / Biology / herpetofauna / riparian / saltcedar / side-blotched lizard / Virgin River

Présentation

Version intégrale (0,53 Mb)

Page publiée le 8 novembre 2012, mise à jour le 25 septembre 2019