Per communication with Chris Walters at NLGRP, Salix arizonica cuttings have produced good survival results in a cryoexposure test with small sample size, which attests to the applicability of the technique. However, Salix seeds may also be stored by at -18 C in orthodox seed banks if quickly processed and stored. So, cryopreservation may not be the only option for this species.
Through the CPC-USFS Region 3 rare plant seed banking agreement, the Institute for Applied Ecology collected conservation cuttings from three meta populations (eight subpopulations) of Arizona willow throughout Santa Fe National Forest including the Pecos Wilderness and San Pedro Parks Wilderness in summer 2022. Cuttings are currently being maintained for later germplasm storage on a propagation block. In total, IAE collected 246 cuttings from 123 maternal plants.
Because ungulate herbivory was identified as a potential threat to Salix arizonica in northern Arizona, to test the extent to which cattle and/or elk herbivory impacted plant growth and survival The Arboretum at Flagstaff augmented an existing population in June and August 1995 with a total of 170 plants. Joyce Maschinski propagated experimental plants from 2 of the 3 existing plants in the population -the only ones healthy enough and large enough to use. Establishing plants required three trials and very sturdy caging. Each plant had fencing with three 5 foot fence posts. Experiments indicated that both elk and cattle ate plants and reduced plant growth. After the herbivory experiments were completed, the introduced plants remained at the site to augment the population. By Oct 1995, 128 plants survived the experiments and climatic conditions. By Sept 2002, 54 plants persisted at the site and by June 2005 41 remained. All remain in cages to protect from herbivory and a few have produced female flowers. No seedlings have been observed.
Water impoundments and diversions
Rust infection (unidentified)
Invasive, non-native plants
(USFWS 1997; Arizona Game and Fish Department 1999
8 populations in Arizona, 4 in New Mexico, and 5 in Utah. The Utah populations are extremely large with thousands of individuals.
Studies by Maschinski (2001) have shown that Arizona willow growth and reproduction is significantly impacted by grazing animals. Because numbers of cattle and elk are very high in New Mexico and Arizona, the populations there are threatened to the greatest extent. A depauperate population in Arizona on Stinky Creek was augmented with approximately 100 caged individuals. Once through an establishment period, the willows persisted, but there is no evidence of seed germination.
Very large populations in Utah are stable. In Arizona there is a conservation agreement for the protection of the species. Most of the populations are either caged or have had livestock excluded. There is intention by the USFS to monitor populations in New Mexico and Arizona. (Arizona Willow Interagency Technical Team 1995)
Continued monitoring is necessary to assess levels of browsing damage by cattle and wildlife.
Cages protecting the Arizona populations should be repaired.
Studies on the biology and ecology of the unidentified orange rust that has been found on some populations of this species.
Seed is recalcitrant, therefore plants must be maintained vegetatively. Valerie Pence at the Cincinnati Zoo and Botanical Garden is studying tissue culture techniques with different species of willow embryos.
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