Is your Phragmites native?

If you work in wetlands, you have no doubt marveled at the spectacular common reed (Phragmites australis). This grass can tower over a field biologist, growing up to 15 ft tall. It is frequently found along streambanks and ditches in Colorado. Often considered an aggressive non-native, recent development of molecular markers has led to the discovery that both native and introduced genotypes exist in North America. This evidence suggests that land managers should think twice before treating common reed like an invasive weed.

Common reed (Phragmites australis) grows in a tall stand in wetlands along the Arkansas River.

It can be difficult to determine native vs. introduced Phragmites using morphological characters. Luckily, Dr. Bernd Blossey has created a handy guide to help distinguish between them. If looking at this table makes you dizzy, the website also offers a free diagnostic service. Send them your common reed specimen, and they will key it out for you! Crystal Strouse, Fort Collins Natural Areas botanist, recently suspected that a population of Phragmites at Running Deer Natural Area was native. After sending material to Bernd Blossey, it was confirmed that the Running Deer population belongs to the native genotype of common reed. At CNHP, we plan on making more collections of this species during the 2015 field season to help determine how common the native genotype is in Colorado.

A stand of common reed (Phragmites australis) at Running Deer Natural Area was identified as the native genotype.

Common Wetland Plants of Colorado’s Eastern Plains: A Pocket Guide

CNHP is excited to announce the release of the Common Wetland Plants of Colorado’s Eastern Plains: A Pocket Guide.  The pocket guide is a complimentary publication to the comprehensive Field Guide to Colorado’s Wetland Plants. The Pocket Guide highlights common wetland plants, both native and non-native located within the Eastern Plains. It is designed to help landowners and other wetland managers correctly identify common wetland plants, manage for preferred species, and control noxious ones.

Cover photo: a playa on the plains

The Pocket Guide contains 119 species with 6 key characteristics (with bolded highlights of diagnostic characters), similar species, habitat and ecology comments, and management comments.

Sample page from the pocket guide

This project was made possible with an U.S. EPA, Region 8, Wetlands Program Development Grant with in-kind match from the Colorado Parks and Wildlife Wetland Program and Colorado State University. The Pocket Guide is available for free from CNHP or can be mailed for $6.00 shipping and handling cost.  One can order from the CNHP Wetland Information Center website here or contact Denise Culver (Denise.Culver@colostate.edu) for more information.

New Report: Year 7 Weed Monitoring at the Air Force Academy

CNHP GIS Program Manager Amy Lavender walks a Canada thistle monitoring transect at the Farish Memorial Recreation Area.

CNHP staff Renée Rondeau and Amy Lavender completed their seventh year of noxious weed monitoring, analysis, and reporting for the U.S. Air Force Academy (AFA) and Farish Memorial Recreation Area (FMRA) near Colorado Springs.

The latest report includes a summary of the results of the past seven years of population monitoring of targeted noxious weeds, emphasizing changes that were observed between 2010 and 2011.

This report and all previous years' reports are available on the CNHP reports page.

Highlights of 2011 monitoring include:

• Russian knapweed: aggressive spraying has extirpated the few known populations. Continued monitoring is necessary to assure that this species is permanently eliminated from the AFA.
• Musk thistle: Number of plants increased over at the AFA despite treatments, but the species appears to be declining at FMRA.
• Canada thistle: cover increased in untreated areas at AFA, but the species appears to be declining at FMRA.
• Leafy spurge: At this time, herbicide treatment appears more effective than biocontrol, and should be continued.
• Myrtle spurge: Aggressive treatment is having a positive impact, but the species is not yet eradicated.
• St. Johnswort: Overall, the 2011 occupied area and number of individuals remained similar to 2010. Careful and coordinated treatment should continue.
• Scotch thistle: occupied acres remain the same, but density of individuals is decreasing. Ongoing weed management is critical for this species.
• Spotted knapweed: this species has reached high numbers. We intend to conduct an herbicide vs. biocontrol study in 2012, utilizing the predicted models developed in 2009 to develop the study in collaboration with Texas A&M.
• Tamarisk: continued management and monitoring is necessary, but treatments appear to be keeping this species under control.
• Houndstongue and Dalmatian toadflax: these two species are relatively new to the area. Aggressive treatment in resulted in the eradication of Dalmatian toadflax, but houndstongue is still present.
• Yellow bedstraw: This weed was discovered at one area in 2010. Rapid response has been very effective.
• Yellow toadflax: Mixed results at FMRA suggest this species was eliminated from one area but continuing to increase in others.

Weed invasion: resistance is not futile!

Renée Rondeau has been working on a vegetation comparison study with a 20-year time frame at the U.S. Air Force Academy in Colorado Springs. She chose sites that in 1991 were observed to be free, or nearly free, of weeds and looked at whether they were still weed-free in 2011. Here are four repeat-photography pairs of different native plant communities, and the observed change in species composition (click photos for larger versions):

Native grasses with a trace of smooth brome - no change.

Native grasses with yellow toadflax - decreased.

Mountain mahogany and mountain muhly with a trace of weed species - decreased.

Gambel oak and native grasses with yellow toadflax - a slight increase.

Although weeds are prolific in and around the Academy, these high quality native plant communities have so far successfully resisted significant weed invasion. This result indicates that functioning, high quality occurrences of native vegetation are both resistant and resilient. Clearly, conserving high quality plant community occurrences is important and should be regarded as an efficient tool for weed control, because weed management and native vegetation restoration is expensive and difficult.

More information about noxious weeds in Colorado and why controlling them is important is available from the Colorado Noxious Weed Management Program.

Job Opening: Weed Mapping Technicians

We have seasonal job openings for up to 6 experienced field mapping technicians to map noxious weed species at the U.S. Air Force Academy and Farish Recreation Area in El Paso County, Colorado.

This position requires field botany and basic GIS skills. The successful candidates will be able to use dichotomous keys or field guides to correctly identify weed species, and have the necessary technical skills to use GPS and ESRI’s ArcPad and ArcGIS software to accurately map and attribute infestations. Field work will be performed independently, and you must provide your own transportation daily to the work location. A computer station will be provided at the Air Force Academy for daily data download and processing.

Work duration will be approximately from April through September, 2012. First consideration of applicants will begin April 2, 2012. Applications will be accepted until all positions are filled. For more information on the position and how to apply, see the full announcement on our Employment and Volunteering page.

New Report - Year 6 Weed Monitoring at the Air Force Academy

CNHP Ecologist Renée Rondeau, Chief Scientist Dave Anderson, and GIS Manager Amy Lavender have completed their sixth year of noxious weed monitoring, analysis, and reporting for the U.S. Air Force Academy near Colorado Springs.

In 2009 the sampling methodology of this project was adjusted based on analyses of data from the past four years, and the fieldwork was streamlined to focus resources on the most urgent weed management challenges. Increased emphasis has been given to invasive weeds for which relatively inexpensive management efforts have a high probability of success.

The latest report includes a summary of the results of the past six years of population monitoring of targeted noxious weeds, emphasizing changes that were observed between 2009 and 2010. For the Year 5 report we developed a suitable habitat model and predicted the pace of spread for spotted knapweed. During the 2010 field season we field verified these models.

See the full report on our new and improved reports webpage.

A 4 meter sampling plot showing infestation with Canada thistle (Cirsium arvense).

Protecting the Dolores River skeleton plant

Note - Jude Sirota, Mesa County Weed and Pest Inspector, sent us this update on how she and her contractors have modified their weed control procedures to accommodate rare plants in the area. Thank you Jude, we really appreciate it!

By Jude Sirota
Weed and Pest Inspector, Mesa County Division of Pest Management

Two lonely dirt roads parallel the Dolores River north of Gateway, Colorado. Along these two roads a rare native plant grows, Dolores River skeleton plant (Lygodesmia doloresensis). It somehow persists in the face of road maintenance — blading, erosion and routine maintenance — and it grows alongside a state-listed noxious weed and growing menace, Russian knapweed (Acroptilon repens).

Dolores River skeleton plant (Lygodesmia doloresensis). Photo by Peggy Lyon.

While on a tour of the area with the Nature Conservancy and the Colorado Natural Heritage Program, I learned about this scraggly, delicate, yet durable native. I was disheartened to see it growing within 6 inches of invasive knapweed plants, which I was responsible for treating on county roads. I promised Susan, Peggy, and Betsy that I would do my best to prevent the demise of their beloved plant.

The county contractor was due to spray the roads for knapweed in mid September and had been warned that there was a rare plant in the area. On September 9th Casey Holman, a seasonal crew member, and I traveled to Gateway with spray and garbage bags in hand. We drove up and down the dusty back roads until we found a skeleton plant. If there was knapweed growing within 30 feet of the native, we gently wrapped the Lygodesmia in a plastic garbage bag, all the way down to the soil, secured the bag with rocks, and treated the nearby knapweed with an herbicide. After uncovering the Lygodesmia, we placed orange flags with a big black "R" on them up and down the road from the patch so that the contractor would know to avoid spraying those patches.

On the drive back to the office, we felt good knowing we had done our part to protect a rare native plant. It was somewhat painstaking and may have seemed ridiculous to a passer-by, but I’m confident that our efforts will eradicate the knapweed (at least in a local sense) and reduced the threat to the native plants.

Noxious weed monitoring at the U.S. Air Force Academy

Ecologist Renee Rondeau mapping weeds on the U.S. Air Force Academy

The US Air Force Academy ("the Academy") near Colorado Springs has established management objectives for weed control in order to remain compliant with state and local noxious weed regulations. Noxious weeds threaten the viability of rare and imperiled native species by competing for resources and actually altering the structure and function of the ecosystems they invade. Once noxious weeds become established in an area, restoration efforts become increasingly difficult and expensive.

The Academy contracted with CNHP in 2002 to survey and map noxious weeds to inform the development of an integrated weed management plan. We have performed additional monitoring surveys since then to provide the Academy with an indication of the effectiveness of their management plan and how it should be adjusted over time.

Our latest report on our weed monitoring efforts at the Academy is now available and includes a summary of the results of the past five years of population monitoring of targeted noxious weeds at the Academy, emphasizing changes that were observed between 2008 and 2009. In addition to field surveys, we also used our data to model suitable habitat and predicted rate of spread of one of the monitored weeds- spotted knapweed (Centaurea maculosa), an aggressive weed that has been spreading quickly- to give the Academy decision support tools to help manage this weed.

Spotted knapweed (Centaurea maculosa) suitable habitat probability (top) and predicted spread over time (bottom) at the Academy.  Analyses by Karin Decker and Michelle Fink. Click on images for larger versions.