Research conducted with Dr. Aldo R. Pinon-Villarreal and Dr. A. Salim Bawazir as part of the National Science Foundation Research Experiences for Undergraduates, convened at New Mexico State. This NSF REU supported the Re-Inventing the Nation’s Urban Water Infrastructure program. The research was titled, “Stem water potential in desert willow grown in clinoptilolite zeolite and in-situ riparian soil”. The abstract follows:

Reestablishing native vegetation in riparian areas of southwestern United States is difficult because of the reduction of natural floods by channelization practices, timing of rainfall, and competition against saltcedar. A previous study demonstrated that clinoptilolite zeolite (CZ) could be used as a wicking material to raise sufficient moisture from shallow groundwater (< 3 m deep) to sustain plant establishment and growth. However, no studies have explored the effects that CZ has on water stress in established vegetation. This study evaluated the stem water potential (ψstem) of desert willow (Chilopsis linearis) grown in CZ cores or unamended in-situ riparian soil (RS) as part of a riparian zone rehabilitation study in Sunland Park, New Mexico. Root zone volumetric moisture content (θv), plant ψstem, and leaf chlorophyll content (LCC) for three to four randomly selected specimens in each substrate treatment within different DGW zones were undertaken from June 7 to July 7, 2016. Results from the study showed that the CZ treatment in Zone 2 under a deeper DGW of 2 m had significantly lower ψstem than the RS treatment (p = 0.002 – 0.06). However no differences in treatment ψstem averages were found in Zone 1 under a shallower DGW of 1.4 m (p = 0.90 – 0.95). Root zone θv was negatively correlated with ψstem, but this relationship was weaker for CZ treatments. Most treatment θv and LCC averages decreased while ψstem increased over the course of the study. This was related to low precipitation and the consistent increase in mean temperatures, with daily maxima reaching as high as 41°C and during the study period. These results can be used to determine the appropriate groundwater conditions where CZ could be used in future urban riparian restoration projects.

Kristina’s full study can be accessed online.

 

Figure 1. Map of the Sunland Park Test Bed riparian rehabilitation area showing planting zones for five native plant species and groundwater piezometers.

Figure 2. Map of desert willows grown in riparian soil (RS) and clinoptilolite zeolite (CZ) cores at the Sunland Park Test Bed

Figure 5. Stem water potential vs. volumetric moisture content for both depth to groundwater zones