Aravaipa Habitat Project

Sky Island Alliance volunteers are bringing back a lost native plant community along the banks of Aravaipa Creek in the Galiuro Mountains in Southern Arizona. By removing invasive periwinkle (Vinca major) and planting native plants, we are enhancing habitat for many Sky Island species including loach minnow and spikedace.

This project is powered by a partnership with The Nature Conservancy, University of Arizona, National Park Service, Gila Watershed Partnership, US Fish and Wildlife Service, and National Fish and Wildlife Foundation.

Proyecto Hábitat de Aravaipa 

Los voluntarios de Sky Island Alliance están trayendo de vuelta una comunidad de plantas nativas perdidas a lo largo de las orillas del Arroyo Aravaipa Creek en las montañas Galiuro en el sur de Arizona. Al eliminar a la invasiva hierba doncella (Vinca major), y plantar flora nativa, estamos mejorando el hábitat para muchas especies de vida silvestre de las Islas del Cielo, incluyendo el pez carpa y el pez espiga.

Este proyecto es impulsado gracias a una asociación con The Nature Conservancy, la Universidad de Arizona, el Servicio de Parques Nacionales de los Estados Unidos, Gila Watershed Partnership, el Servicio de Pesca y Vida Silvestre de los Estados Unidos y la Fundación Nacional de Pesca y Vida Silvestre de los Estados Unidos.




ARAVAIPA CANYON 

Roughly 118 miles southeast of Globe, Arizona lies the Aravaipa Canyon Wilderness, a 19,000-acre expanse of land that’s home to perennial water sources, abundant sycamore, ash, and cottonwood trees, and unpaved hiking trails. The Bureau of Land Management describes the riparian vegetation of this wilderness as “dense … a sign of a healthy ecosystem.” 

Since the 1900s, however, invasive flora has appeared in the Aravaipa Canyon Wilderness, most likely introduced by early homesteaders—ranchers and farmers—who planted non-native flora for their ornamental value and ground cover (which helped prevent weed growth). 

Giant reed, buffelgrass, Sahara mustard, tamarisk, and tree of heaven are all problematic invasive species in the Aravaipa Canyon Wilderness, but one species of specific focus for us is vinca (Vinca major), a vine-like understory plant from Europe that is challenging to eradicate. 

ABOUT VINCA MAJOR  

Vinca major is a pretty plant, but a seriously invasive species that prevents native plant growth in the Sky Island region. Image by inkflo from Pixabay.

Vinca, also known as bigleaf periwinkle, grows pink and purple flowers in the spring and summer. These blooms don’t contain seeds or produce fruit; instead, vinca creates ongoing plant populations through clonal growth—a type of asexual reproduction where the offspring grows directly from the parent plant until it takes root. This single colony spreads, creating  a thick carpet-like covering called a “monotypic stand” that makes it hard for other species to take root. 

IMPACT OF INVASIVE SPECIES IF LEFT TO SPREAD 

Invasive species like vinca can change the diversity of flora in an area and even stop the development of new seeds or existing seedlings. This smothering effect can even inhibit fresh tree growth. 

Vinca is considered a “novel life form in western U.S. riparian zones” such as the Aravaipa Canyon Wilderness (source: Desert Plants), which researchers speculate gives vinca an advantage over native species that are not competitive or adapted to resist monocultural growth. Vinca also spreads quickly through floods—which can happen after monsoon storm events—that help carry and root portions of old colony growth throughout various parts of the wilderness. 

Invasive vinca poses great concern to areas like the Aravaipa Canyon Wilderness. The native flora and fauna in these places are diverse and need to be protected, but a change in ground cover can hinder their success. For example, a study on vinca in Australia found that it covered the ground so thickly, a lizard species had to climb on top of the vinca canopy to bathe in the sun, a response to new plant growth that put them at risk of predation (Hedrick et al. 2019). It’s not hard to imagine the lizards that call Aravaipa Canyon home having to put themselves in a similarly vulnerable position if vinca spreads unchecked. 

REMOVING VINCA 

Vinca is rarely affected by pests or diseases in the United States. Successful eradication of invasive vinca depends on human intervention to stop it from spreading. 

Sky Island Alliance has worked closely with The Nature Conservancy for many years to remove invasive vinca from along Aravaipa Creek in the Galiuro Mountains. New research published in Desert Plants by Hedrick et al. (2019) suggests two approaches for removing vinca: remove the plant and as much of the root system as possible in the spring or mow the plant down and apply herbicide to the cut stems. 




While we acknowledge the effectiveness of using herbicides on invasive vinca, Sky Island Alliance specializes in the manual removal of vinca in sensitive habitats like creek banks where herbicide application could harm aquatic life. We remove invasive vinca by hand and restore the cleared area with native plants that enhance the habitat of this region for many Sky Island species. 

Look for opportunities to volunteer for an upcoming vinca removal campaign in Aravaipa Canyon in 2021! 

REFERENCE 

Hedrick, P. W., H. Blankenship, M. Haberstich. 2019. Invasive Plants in Aravaipa Canyon, Arizona: Invasion History, Life History, Problems, and Control. Desert Plants, 35 (2): 4-24.