Floristic Inventory of the Arapaho National Forest
and Bureau of Land Management Lands in Grand County, Colorado
By Erin Foley
Masters Candidate Botany
University of Wyoming
I would like to express my sincere thanks to the Colorado Native Plant Society for support of my master’s research in botany. With the help of the Society, the University of Wyoming, the Arapaho National Forest (NF), the Colorado Bureau of Land Management (BLM), and many others, I was able to complete two summers of botanical fieldwork in north-central Colorado.
The following article presents a summary of my floristic research in the Arapaho NF and on Grand County BLM Lands during the summers of 2003 and 2004.
The imminent loss of plant biodiversity and an insatiable desire to learn about plants led me to the masters program in floristics at the University of Wyoming. Botany Professor, and Rocky Mountain Herbarium curator, Dr. Ron L. Hartman welcomed me into the program, where I equally welcomed the opportunity to do a floristic inventory of the Arapaho NF and Grand County BLM. Coming from the glaciated flats of southwestern Ohio, I was in for many botanical treats in the Rocky Mountains.
The study area included about 1,500 square miles at elevations ranging from 6,800 to 14,270 feet, and presented a diversity of terrain and plant life which I had not seen before. From alpine peaks to the banks of the Colorado River, I worked to document this diversity by choosing collection areas according to season and elevation. I placed an emphasis on alpine habitat, sensitive plants, and invasive and noxious weeds. Sensitive plants and weeds are of particular interest to land managers, and some alpine plant species may be under threat given current warming trends. Our knowledge of the effects of global warming on alpine habitat is limited. Kevin Krajick, in his 2004 Science article “All Downhill From Here,” summarizes a number of research projects from around the world that document the decline of alpine species. This research reinforces the need for additional botanical inventories and justifies the emphasis placed in this inventory.
In total I documented 71 different alpine and subalpine localities. With the snowmelt in June of 2003, I made my first venture into the alpine, and I was astonished with what I saw. The Spring Beauty of my Ohio back yard paled next to the Alpine Spring Beauty (Claytonia megarhiza var. megarhiza) of Rocky Mountain peaks, and the Forget-me-not I knew was nothing like the unforgettable Alpine Forget-me-not (Eritrichium nanum var. elongatum) of windswept alpine knolls.
These charismatic alpine plants caught my attention. However, I did not forget the council of Dr. Ron Hartman who advised me to keep an eye out for the more inconspicuous plants, such as tiny alpine mustards. This advice proved beneficial. In the Arapaho NF, I recorded 14 occurrences of 5 sensitive Draba spp. including: Draba crassa, Draba exunguiculata, Draba fladnizensis var. pattersonii, Draba grayana, and Draba porsildii var. porsildii. Along with these Draba spp., I observed six additional sensitive species in alpine habitat, totaling 11 and comprising 44% of the sensitive taxa encountered in this study. (Reports of these sensitive species have been provided to the Colorado Natural Heritage Program and appropriate land managers.)
The alpine habitat was fascinating with its striking exposed landscapes and unique vegetation yielding many sensitive plants. I was excited to discover equally fascinating terrain and vegetation at much lower elevations in Grand County. There the Colorado River and Muddy and Troublesome Creeks wind their way through the captivating geology of Middle Park. On exposed badland hills, instead of snow crystals, I found gypsum crystals glazing the surface, and on sagebrush hills it was Paronychia sessiliflora, Creeping Nailwort, not Paronychia pulvinata, Rocky Mountain Nailwort, that I saw.
Also at these lower elevations, I observed a greater abundance of non-native taxa and noxious weeds. Of 93 non-native taxa collected (including 18 noxious weeds), 70% of occurrences were below 9,000 feet, and 50% of noxious weeds were found at elevations below 8,000 feet. These findings were not surprising, given stronger human-induced disturbances at lower elevations. However, exceptions to this trend were noted. I found Cheat Grass (Bromus tectorum), the most common noxious weed with 36 collections, growing above 10,000 feet, and Wild Caraway (Carum carvi) and Nodding Plumeless Thistle (Carduus nutans) growing at 11,400 and 10,400 feet respectively.
Disturbance, did not always mean weeds, and at one collection locality a disturbed site presented an important surprise. Along an unused ATV trail that had been blocked off by boulders, several of the federally endangered Astragalus osterhoutii had established themselves. It appeared that seeds from a neighboring badland hill had washed down, finding the disturbed open soil suitable. This population had not been recorded, and its documentation provided timely and useful information to the BLM for land management decisions.
I was fortunate to have been taught the fine-tuned methodology utilized and developed by the Rocky Mountain Herbarium. These methods provided the structure and tools for a successful inventory. I collected plants using a bricklayer’s hammer which was useful for getting underground roots and rhizomes. I transported plants in plastic bags and later stored them in coolers with gallon jugs of ice. I took GPS and habitat information along each collection route, noting pertinent information.
Collecting days were long, but often not as long as days inside pressing plants. The “company” indoors included stacks of cardboard, maps, collection notebooks, and the warm glow generated by the 6’ x 20” x 24” plywood plant drier, heated by a row of 150 watt light bulbs. On these days there was ample time to get better acquainted with the plants. Clumps of soil held by stubborn roots were patiently tapped away, flowers were carefully placed to make parts accessible for identification, and plants, such as Squirreltail, Elymus elymoides, which attempted to creep out of the newspaper, were gently pushed back in. On topographic maps I drew the collection route for each locality, and in my collection notebook wrote out locality information. I also recorded the genus of each specimen, assigning each a number, and placed it in the corresponding newspaper. Then the newspapers were stacked between cardboard, strapped down tightly with plywood on either end, and placed on the drier for 36 hours or longer.
In total, 13,496 plant specimens including 1,023 unique taxa and 936 species were collected, processed, and identified with the help of Ernie Nelson, Ron Hartman, Michael Foley, and others. This includes the many botanists who have worked to fill up the cabinets at the Rocky Mountain Herbarium, and who have written floras and monographs with useful keys and descriptions. My research would not have been possible without their dedication, which provided the tools for identification and served as an inspiration on long nights. My results have been given to the Arapaho NF and Colorado BLM, and continuing efforts to share and synthesize information gathered from this study are underway.
I would like to again thank the Colorado Native Plant Society for their research support through the Myrna L. Steinkamp and John W. Marr funds. I am honored to be associated with such an active society that provides opportunities to educate people about and to appreciate and conserve Colorado’s diverse native flora. I am hopeful that Colorado’s Rocky Mountain flora will continue to be documented and that the incredible diversity of this region is perpetuated into the future.
References Cited
Colorado Natural Heritage Program. 2/22/2005. "List of Imperiled Species by County
and Statewide Species and Natural Community Tracking List" [online]. [Cited
May 2005] www.cnhp.colostate.edu/
Krajick, Kevin. 2004. "Climate change: all downhill from here?" Science 12 March 2004; 303: 1600-1602.
State of Colorado Department of Agriculture. 1996. "Colorado Land Ownership
Summary by County: Totals for Federal, State, and Private Lands" (1996). [online]. [Cited 6 Nov 2005]
www.ag.state.co.us/resource/documents/TotalCOfederallandownership.xls
State of Colorado Department of Agriculture. 2005. Plant Industry Division: 8CCR
1203-19 "Rules Pertaining to the Administration and Enforcement of the Colorado Noxious Weed Act". [online]. [Cited May 2005]. http://www.ag.state.co.us/CSD/Weeds/statutes/weedrules.pdf
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Colorado Native Plant Society
P.O. Box 200
Fort Collins, Colorado 80522
or phone her at (303) 458-4262 for further information.