Searching for Pocket Mice in the San Luis Valley

The Rio Grande National Forest is revising their 1996 Forest Management Plan. The Forest Management Plan is the guiding document for all management decisions and activities on the Rio Grand National Forest. As part of the update, Rio Grande NF staff are seeking more information on rare species. This summer, the Rio Grande hired CNHP zoologist Rob Schorr to survey for several lesser-known and rare small mammals. Two of the primary targets were the silky pocket mouse (Perognathus flavus sanluisi) and the plains pocket mouse (Perognathus flavescens relictus), both of which are unique to the valley. These pocket mice prefer the sandy soils of the San Luis Valley. Schorr and his daughter spent time trapping for the pocket mice on US Forest Service lands north of Great Sand Dunes National Park. They trapped in eight different areas, catching one silky pocket mouse and two plains pocket mice in sandy, sparse grasslands below pinyon and juniper forests.

The plains pocket mouse capture site with sandy soils, tall grasses, and rabbitbrush (Chrysothamnus spp.).

A close-up of a plains pocket mouse.

One of the two plains pocket mice captured on Rio Grande National Forest lands in 2015. 

The silky pocket mouse capture site on the Rio Grand National Forest. The site has sandy soils and large patches of blue grama (Bouteloua gracilis).

Natural Resource Management Decision-Making under Climate Uncertainty: Building Social-Ecological Resilience in Southwestern Colorado

In joint collaboration with several other institutes, the Colorado Natural Heritage Program was awarded a multi-year project from the North Central Climate Science Center (part of U.S. Geological Survey): “Natural Resource Management Decision-Making under Climate Uncertainty: Building Social-Ecological Resilience in Southwestern Colorado.”  Renée Rondeau, Ecologist and Conservation Planner with the Colorado Natural Heritage Program is the CSU Principal Investigator and will be working closely with Jeffrey Morrisette and Dennis Ojima (North Central Climate Science Center), as well as University of Montana, The Nature Conservancy, Mountain Studies Institute and USGS-Fort Collins over the next few years to facilitate climate change adaptation that contributes to social-ecological resilience, ecosystem/species conservation, and sustainable human communities in Southwestern Colorado while focusing on the Gunnison Basin and the San Juan Mountains.  

Gunnison Basin landscape with East Beckwith Mountain in the background.

The group will develop a set of actionable and prioritized social/ecological adaptation strategies for vulnerable ecosystems and species based on best available science.  These adaptation strategies will incorporate the latest in climate science and must be useful and meaningful to natural resource managers and other stakeholders.  The Gunnison and San Juan Basins ownership and economies revolve around ranches and private industry that relies on natural resources, US Forest Service, US National Parks, Bureau of Land Management, and Tribal Lands, and will be integral in the success of this project.  The frameworks that are developed for this project should be applicable to other western landscapes and will help guide communities in adapting to changes associated with a changing climate.  

Fen mapping at the Pike and San Isabel National Forests

Fens are a special type of wetland - they are fed by groundwater, support vegetation that is very different from the plants on the surrounding uplands and some contain water that is alkaline (high pH values) or mineral rich. Fens are often dominated by rushes and sedges and they can support mosses, willows and even some trees.   

During the warm seasons between 2004 and 2009, fen expert David Bathke surveyed wetlands that could potentially contain fens on the Pike and San Isabel National Forests.  He visited places that been identified as emergent and shrub wetlands in the National Wetland Inventory to see if any of these wetlands contained fens. The resulting surveys contained a wealth of information: fen determinations and boundaries, lists of plant species, soil measurements, and observations on hydrologic processes at each site.  CNHP recently got involved when the US Forest Service requested that we use our photo-interpretation and GIS expertise to convert these data (that only existed on paper) into digital geospatial data (GIS data).  This data will help the US Forest Service better understand and protect the fens on their land.

A fen complex in Pike/San Isabel National Forest.
The fens are outlined in yellow, the  NWI wetland is outlined in purple.

The fen complex pictured above contained a diverse array of plant species including water sedge (Carex aquatilis), peat moss (Sphagnum angustifolia), white water-crowfoot (Ranunculus aquatilis), diamondleaf willow (Salix planifolia), and resin birch (Betula glandulosa).

Iron fens at Geneva Creek, note the terracing of the unvegetated surface.

Iron fens are a special type of fen that occur on iron-rich substrates, and are unique to Colorado.  The water that flows the iron-rich substrate is acidic and mineral rich, and forms limonite (iron saturated peat) which forms terraces and ledges. Note the small forested fen in the bottom left corner of the above photo: this forested iron fen is dominated by dwarfed Engelmann spruce (Picea engelmanni).

New Report: Assessment of Wetland Condition on the Rio Grande National Forest

CNHP Wetland Ecologist Joanna Lemly recently completed work on a project to characterize and assess the condition of wetlands on the RioGrande National Forest (RGNF) in south central Colorado. The project was carried out in conjunction with CNHP’s first river basin scale wetland assessment in the Rio Grande Headwaters River Basin.

Headwater wetlands in the Sangre de Cristo Mountains of the RGNF.

Between 2008 and 2011, CNHP partnered with Colorado Parks and Wildlife (CPW) on a U.S. Environmental Protection Agency (EPA) funded effort to map and assess the condition of wetlands throughout the Rio Grande Headwaters River Basin, which includes the RGNF. Existing paper maps of wetlands created by the U.S. Fish and Wildlife Service (USFWS)’s National WetlandInventory (NWI) program were converted to digital data by GIS Analysts at CPW. In addition to the mapping, 137 wetlands were surveyed across the Rio Grande Headwaters basin using condition assessment methods developed at CNHP over the past decade. Of the wetlands surveyed, 52 were located on the RGNF in 10 different watersheds. To supplement the EPA-funded study, the U.S. ForestService (USFS) provided funding through a Challenge Cost Share Agreement for additional wetland sampling on the RGNF to develop more comprehensive information about the types, abundances, distribution, and condition of the Forest’s wetlands. Through the agreement, 25 additional wetlands on the RGNF were surveyed and all data from the RGNF were summarized.

Field crew members sampling a fen wetlands on the RGNF.

  Based on digitized NWI mapping, we now know the following facts about wetlands on the RGNF:

·        There are 42,862 acres of wetlands and water bodies within the RGNF.
·        Lakes and rivers comprise 4,687 acres or 11%.
·        Wetlands and water bodies represents approximately 2% of the total land area in the RGNF.
·        Slightly over half (55%) of NWI mapped acres are freshwater herbaceous wetlands.
·        Shrub wetlands make up another 30%.
·        When broken down by hydrologic regime, saturated wetlands are the most common, comprising 73% of NWI acres.
·        Within the RGNF, 82% of all lakes are mapped with a dammed/impounded modifier, indicating that most lakes are reservoirs of one kind or another.
·        Beavers influence only 4% of all wetland acres, but 23% of ponds are mapped as beaver ponds and 6% of shrub wetlands are mapped with beaver influence.
·        65% of all NWI acres occur in the subalpine ecoregions, which make up roughly the same proportion of the Forest’s land area.
·        Another 29% of NWI acres occur in the alpine zone. Lower elevation zones contain very few wetland acres.

Down cutting of a small stream observed near a wetland in the Rio de los Pinos watershed of the RGNF.

Field surveys resulted in additional information about RGNF wetlands.

·        In total, 77 wetland sites were surveyed across the RGNF, including 30 riparian shrublands, 27 wet meadows, 17 fens, two riparian woodlands, and one marsh.
·        Nearly 500 plant taxa were encountered during the surveys, including 445 identified to the species level.
·        Of the 445 identified to species level, 420 (94%) were native species and 25 were non-native species.
·        Noxious weeds, an aggressive subset of non-natives, were present in only four plots.
·        Wetland condition measures indicate that wetlands on the RGNF are in excellent to good condition.
·        Floristic quality assessment indices were high for most wetlands, though did vary by both elevation and wetland type.
·        Multi-metric Ecological Integrity Assessment (EIA) scores rated most wetlands with an A- or B-rank, indicating that wetlands were either in reference condition or deviated only slightly from reference condition.
·        A handful of wetlands received C-ranks, due to stressors including grazing, hydrologic modifications, and surrounding land use.

 In conclusion, the RGNF contains thousands of acres of high quality wetlands that provide essential services to the Forest and lands downstream. This study, in conjunction with others carried out by CNHP over the past two decades, provides the RGNF with detailed information on specific wetlands throughout the RGNF along with generalize conclusion on the extent, distribution, and condition of wetlands. This information can be used for a variety of management purposes.