Inventory for Navajo Sedge, Carex specuicola, along Seeplines at Natural Bridges National Monument

Abstract

Hanging gardens are an important part of the landscape at Natural Bridges National Monument (NABR) and are the most common type of spring within the park. These hanging gardens support a diversity of plant species including the federally listed threatened Navajo Sedge (Carex specuicola; CASP). CASP is confined to seep and spring emergences in sandstone outcroppings in the Four Corners area. Populations of CASP are known throughout northern Arizona and in southern Utah just south of NABR. Much of the potential habitat in southern Utah has not been surveyed for the species. Occurrences of CASP within NABR are at the northernmost extent of CASP?s range in the region and are also unique because they are in a canyon that is tributary to the Colorado River rather than the San Juan River. Since the extent of CASP populations were largely unknown, the objective of this project was to conduct a follow up inventory for CASP at hanging gardens in NABR to help document occurrences of this species at NABR, its presence and absence in suitable habitat, and suggest sites to be incorporated into the regional monitoring program. Sites with positive occurrence of CASP could be targeted for increased protection by the park. Knowledge of these sites may also be used to advocate for management decisions such as the protection of water resources that recharge the springs of CASP habitat. This project resurveyed 64 previously known hanging gardens for CASP and documented and surveyed 26 new seeps found near the existing sites. CASP was not detected at the majority of sites. Four suspected CASP occurrences were documented, two of which had not been previously documented. Data and clippings of the leaves were taken from all new, suspected, or previously known CASP populations for genetic analysis. Genetic analysis of leaf specimens collected at Doug Fir North, North Doug Fir 7, Sipapu 1, and White Canyon 2 confirmed the presence of C. specuicola at these sites.