In 2019, the Colorado Natural Heritage Program repeated Anderson (2001) density estimates for the entire milkvetch (Astragalus schmolliae) population on Chapin Mesa within Mesa Verde National Park (MEVE). A total of 197-100 x 10 m belt transects were established in 2001 (one year before a fire burned nearly 40% of the population) and repeated in 2019. Our observations present multiple hypothesis as to why the burned areas have become less favorable to Chapin Mesa milkvetch, including: 1) seedlings are suppressed due to competition for soil moisture from abundant grass cover, especially cheatgrass, western wheatgrass, and smooth brome, 2) shallow soil temperatures during the growing season are significantly higher in burned areas, which exacerbates depletion of soil moisture, especially when coupled with abundant grass cover, 3) lack of bare ground in burned areas inhibits ground-nesting bees, which may be important pollinators, 4) without tree cover for protection, late frosts are more likely to kill flowers in the burned area as well as increase peak daytime soil temperature.
In 2013, the Colorado office of the Bureau of Land Management (BLM) contacted the Colorado Natural Heritage Program (CNHP) for assistance in conducting a climate change vulnerability assessment to help focus attention on the highest priority species and habitats. In 2015, CNHP completed vulnerability assessments for 98 species and 20 ecological systems. That assessment highlighted two clear priorities for BLM management in Colorado: pinyon-juniper woodlands and native fish. Since the vulnerability assessment was completed, we have continued to work with Colorado BLM to expand our understanding of climate impacts on pinyon-juniper woodlands and fisheries, and to develop data products designed to feed into BLM planning processes at the Field Office scale.
This report summarizes the results of the past fourteen years of population monitoring of noxious weeds at the U.S. Air Force Academy and Farish Recreation Area ("Farish"). Base wide monitoring has been conducted at the Academy at five year intervals: 2002, 2007, 2012 and 2018. (2002, 2007, 2012 and 2017 at Farish). In between years, arial mapping at known sites was conducted at the Academy for species with low cover and permanent plots were used to monitor wide spread noxious weed species at the Academy (2018) and Farish (2016). These data are used to determine population trends. The 2018 basewide survey included 26 species that were mapped across the Academy and Farish. Four new species of noxious weeds were included in the 2018 survey, three new noxious weeds at the Academy and one at Farish.
This document is intended to be a tool for managing lands that support rare, imperiled and/or sensitive plants, animals, and significant plant habitats. The goal of the project was to systematically identify the locations of rare species and significant habitats.
