Basinwide Wetland Profile of the North Platte River Basin

 CNHP Wetland Ecologist and project lead, Joanna Lemly and field volunteer Alexandra Permar discuss hydric soil indicators in a wetland in North Park.

CNHP’s Ecology Team initiated Colorado’s second basin-wide wetland condition assessment this August. Following the success of the pilot Rio Grande Headwaters Wetland Condition Assessment, this second EPA-funded project is focused on the North Platte River Basin in north central Colorado. The project will create a wetland profile of the North Platte River Basin, documenting the spatial distribution of wetland types and ecological condition, and will relate that information to potential threats and stressors.

 Wetland identification and condition assessment protocols include a full description of the soil profile. Joanna finds the exact soil color in her Munsell Soil Color Chart.

The project objectives are to (1) compile existing spatial data on wetlands in the North Platte River Basin; (2) conduct a statistically valid, field-based survey of wetland condition in the basin; and (3) model the distribution of wetland condition throughout the basin using collected field data and additional spatial data on potential threats and stressors. This information is necessary to prioritize on-the-ground efforts for efficient and effective conservation and management.

 Joanna attempts to dig a soil pit in a wetland outside Walden, Colorado.  Some soil pits are harder to dig than others!

Last winter, GIS Analysts with CNHP and the Colorado Division of Wildlife compiled all known sources of wetland mapping for the North Platte River Basin. We also acquired existing paper maps of wetlands created in the 1970s and 80s by the US Fish and Wildlife Service’s National Wetlands Inventory (NWI). These paper maps were scanned in and digitized to create a seamless, wall-to-wall map of wetlands in the basin. From this map, 100 randomly selected sample points were used for the wetland condition assessment.

The available digital NWI data went from this…

...to this!

This is a two phase project. In August, 10% of the sample points were visited and assessed using methods developed at CNHP. These sites will be revisited, along with the remaining points, during the 2010 summer field season. The initial 2009 data collection will allow us to estimate inter-annual variability associated with the assessment methods. This field season also gave the project team an opportunity to explore the basin and its many wetlands in order to ensure that the study design would be successful.

Shale Barrens

From Cañon City in southeastern Colorado to the Kansas and New Mexico borders lies an area of marine rocks dating back to the Cretaceous, exposed by the inexorable erosional processes of the Arkansas River. These exposed shales and soft limestones (chalk) form outcrops of an interesting and important habitat type – shale barrens.

Shale barrens aren't really barren, but no one would
call them lush with vegetation, either.
Photo by Renée Rondeau

CNHP ecologist Renée Rondeau has been documenting these habitats in Las Animas, Pueblo, and Huerfano Counties this past summer. These habitats are extremely vulnerable to surface disturbance such as mining, quarrying, and other activities that lead to changes in soil structure or vegetation structure.

Shale barren outcrops rising out of the prairie.
Photo by Renée Rondeau

The area between Pueblo and Cañon City contains the highest frequency of such shale barrens in southeastern Colorado. Forming low hills above the surrounding shortgrass prairie, the barrens typically have a high percentage of open, rocky ground and sporadic vegetation. Some occurrences have an overstory of sparse juniper and/or pinyon pine, and may include scattered larger shrubs and bunchgrasses. Shale substrates often form a rocky “pavement” between plants.

Clumps of little bluestem scattered through shalely soils.
Photo by Renée Rondeau

A number of Colorado’s rare plant species are found on shale barrens, especially on substrates formed from the Smoky Hills Member of the Niobrara Formation. Some may also occur on the Fort Hayes member of the Niobrara, or occasionally on substrates derived from adjacent Cretaceous formations such as the Carlile Shale, Greenhorn Limestone, and Graneros Shale.

Geology lesson: The Niobrara Formation (yellow) and Carlile Shale,
Greenhorn Limestone, and Graneros Shale formations (brown) in southeast Colorado.

For more information, read CNHP's shale barrens ecological system description (PDF).  Other ecological system descriptions are available on our website.

Fun with fens

CNHP botanists Peggy Lyon and Janis Huggins have been inventorying fens on the White River National Forest this summer. At every site, they must dig a soil pit to check for depth and quality of peat. Peggy sent in this photo of herself reaching as far down as she can into a pit. She says she doesn't mind the occasionally uncomfortable conditions because it's an awesome place to work. This wetland northwest of Silverthorn did turn out to be an actual fen.

Peggy on her way to China

Fens in Colorado are generally small and fairly rare on the landscape. These squishy habitats are found only in specific environments defined by ground water discharge, soil chemistry, and peat accumulation of at least 40 cm (about 16 inches). Fens form at low points in the landscape or near slopes where ground water intercepts the soil surface. The fairly constant year-round water level, with water at or near the surface most of the time, leads to the accumulation of organic material (peat). In addition to peat accumulation and perennially saturated soils, many fens have distinct soil and water chemistry, with high levels of one or more minerals such as calcium, magnesium, or iron.

Plains leopard frog - Rana blairi

The plains leopard frog (Rana blairi)
Photo by Joe Stevens

The plains leopard frog historically inhabited wetlands in the vast prairie grasslands of North America, and still does inhabit prairie wetland remnants, but now has also adapted to areas of human disturbance, including areas used for agriculture and ranching.

If they don't move, they look remarkably like mud
Photo by Renée Rondeau

This species requires open water for breeding but adults can be found some distance away. Some known or hypothesized threats to this species include habitat loss, water pollution, water extraction, pesticides, predation by introduced game fish, competition with introduced fish and amphibians, and climate change resulting in increased aridity.

An example of plains leopard frog habitat in southeast Colorado
Photo by Renée Rondeau

*NEW* Interactive map and additional content on our website

We have added some exciting new content and features to our website.

We now have an interactive map showing our recent activities across the state, and another map of all our county inventories over the years.



Additionally, our GIS data now has its own page, and we have broken out all of our Potential Conservation Area (PCA) reports into single documents organized by name.

As always, we welcome your questions and feedback, and please check back periodically for additional features and updates. Thank you!

Report from the 6th Annual Rare Plant Symposium

The 6th Annual Rare Plant Symposium, an off-shoot of the Colorado Rare Plant Technical Committee, took place on September 11, 2009. CNHP botanists Susan Panjabi and Jill Handwerk presented reviews of Colorado’s rare plant species, and solicited new information from participants. The meeting was attended by 50-60 people, including representatives of the Bureau of Land Management, City of Fort Collins, Colorado Natural Areas Program, Denver Botanic Gardens, The Nature Conservancy, US Fish and Wildlife Service, US Forest Service, University of Colorado Herbarium, and the Wyoming Natural Diversity Database, as well as other interested botanists from the region.

Some highlights included a report of new state records in New Mexico for two species: Porter’s feathergrass (Ptilagrostis porteri), and Colorado Divide whitlowgrass (Draba streptobrachia). Ben Legler was responsible for these finds, as well as discovering a new species of phlox from the Vermejo Park Ranch in northern New Mexico. These two species were previously believed to be endemic to Colorado. Although the new records extend the known range of the species, they are both still considered rare. Tim Hogan reported a county record and range extension for Saussurea weberi in Custer County.

Draba streptobrachia (Colorado Divide whitlowgrass)
Photo by Peggy Lyon

The meeting included quite a bit of discussion about the federally listed species, which have been receiving more monitoring attention recently. Many participants also noted the large number of occurrence records from the northwestern portion of Colorado (especially Moffat County) which have not been observed for 20 years or more. Although we have good records of these species from the late 1980’s, CNHP has so far been unable to secure funding to re-survey these occurrences, or to look for new ones in this area. One of our primary challenges is how to fund the continual updates needed to keep our database current, since “stale” data makes conservation planning and action more difficult.

Ptilagrostis porteri (Porter’s feathergrass)

The endangered Astragalus osterhoutii

Osterhout milkvetch (Astragalus osterhoutii)

CNHP Botany Information Manager Jill Handwerk took these photos of the federally endangered Osterhout milkvetch (Astragalus osterhoutii) earlier this summer. This member of the pea family grows on highly seleniferous (containing the element selenium) soils derived from Niobrara Shale in Grand County. It is a narrowly endemic species estimated to occupy about 800 acres in north central Colorado.

A. osterhoutii in its native habitat - sagebrush shrublands

A few dozen species of Astragalus, including A. osterhoutii, have been identified as “selenium indicators”, accumulating the element in their tissues as they grow on seleniferous soils. In the early decades of the 20th century, selenium was identified as the underlying cause of “alkali disease” which affected livestock that were fed grains or grasses grown on certain soils. Selenium gives a characteristic and lasting garlic-like odor to the plants, and herbarium workers can always tell when someone has opened the cabinet containing these specimens.

Not many plants can grow in such heavy shale soils, but A. osterhoutii likes it

Covering Colorado and beyond...

Every county in Colorado has been a part of CNHP projects. Since 1993, we have completed more than 50 projects with a study area at the statewide level or greater, and more than 250 projects covering smaller areas of Colorado (see map below). Project area sizes may be as small as a few acres, a county, a local watershed, or as large as the eastern plains and the southern Rocky Mountains. Park, El Paso, and Boulder counties top the list with more than 30 projects each in addition to their inclusion in the statewide tally.

Number of projects by county.
This does not include all of our statewide and larger projects.

CNHP is committed to making our project documents available to the public whenever we can. Visit our Documents and Reports page for electronic versions of reports currently available, and check back periodically as we gradually add both new and older publications.