Colorado

Publication Title: 

Can Nitrogen fertilization aid restoration of mature tree productivity in degraded dryland riverine ecosystems?

Authors: 
Andersen, D.C., E.C. Adair, S.M. Nelson, and D. Binkley
Publication Date: 
2014
Parent Publication Title: 
Restoration Ecology
Publication Type: 
Archive number: 
2014/0050 FORT
States: 

Pub Abstract: 

Restoration of riparian forest productivity lost as a consequence of flow regulation is a common management goal in dryland riverine ecosystems. In the northern hemisphere, dryland river floodplain trees often include one or another species of Populus, which are fast-growing, nutrient-demanding trees. Because the trees are phreatophytic in drylands, and have water needs met in whole or in part by a shallow water table, their productivity may be limited by nitrogen (N) availability, which commonly limits primary productivity in mesic environments. We added 20 g N m−2 in a 2-m radius around the base of mature Populus fremontii along each of a regulated and free-flowing river in semiarid northwest Colorado, USA (total n = 42) in order to test whether growth is constrained by low soil N. Twelve years after fertilization, we collected increment cores from these and matched unfertilized trees and compared radial growth ratios (growth in the 3-year post-fertilization period/growth in the 3-year pre-fertilization period) in paired t tests. We expected a higher mean ratio in the fertilized trees. No effect from fertilization was detected, nor was a trend evident on either river. An alternative test using analysis of covariance (ANCOVA) produced a similar result. Our results underscore the need for additional assessment of which and to what extent factors other than water control dryland riverine productivity. Positive confirmation of adequate soil nutrients at these and other dryland riparian sites would bolster the argument that flow management is necessary and sufficient to maximize productivity and enhance resilience in affected desert riverine forests.

Publication Title: 

Modeling elk and bison carrying capacity for Great Sand Dunes National Park, Baca National Wildlife Refuge, and The Nature Conservancy's Medano Ranch, Colorado

Authors: 
Wockner, G., R. Boone, K.A. Schoenecker, and L.C. Zeigenfuss
Publication Date: 
2015
Parent Publication Title: 
Publication Type: 
Archive number: 
2015/0004 FORT

Pub Abstract: 

Great Sand Dunes National Park and Preserve and the neighboring Baca National Wildlife Refuge constitute an extraordinary setting that offers a variety of opportunities for outdoor recreation and natural resource preservation in the San Luis Valley of Colorado. Adjacent to these federal lands, the Nature Conservancy (TNC) manages the historic Medano Ranch. The total land area of these three conservation properties is roughly 121,500 hectares (ha). It is a remote and rugged area in which resource managers must balance the protection of natural resources with recreation and neighboring land uses. The management of wild ungulates in this setting presents challenges, as wild ungulates move freely across public and private landscapes.

The San Luis Valley was historically used for irrigated agriculture and ranching. Historically, livestock, including sheep (Ovis aries) and cattle (Bos Taurus), were grazed throughout the valley. The former Luis Marie “Baca” Ranch, which makes up the northern part of Great Sand Dunes National Park (hereafter “Park”) and all of the Baca National Wildlife Refuge (hereafter “Refuge”), was actively grazed by cattle until 2004. Bison (Bison bison), elk (Cervus elaphus), mule deer (Odocoileus hemionus), and pronghorn (Antilocapra Americana) were native to the area until about the 1840s, when bison, elk, and pronghorn were extirpated.

Elk and pronghorn likely moved back into the area from surrounding populations to the north and south, and mule deer populations have varied through time. A population of 4,400 elk currently inhabits the area. The current bison population was established in 1986 for meat production. In 1999 TNC purchased the ranch and established a bison conservation herd, and eventually subcontracted management to a private rancher in 2005. A population of bison ranging in size from 1,200–2,000 ranges freely within the 16,100 ha Medano Ranch. Ungulate populations in the valley are regulated by hunting, with the exception of bison, which are rounded up and culled annually to maintain population levels.

In an effort to create and form the basis of a multi-agency ungulate management plan for the region, the Park sought the development of an elk and bison ecological carrying capacity model to provide guidance to resource managers.

Publication Title: 

The historical distribution of Gunnison Sage-Grouse in Colorado

Authors: 
Braun, C.E., S.J. Oyler-Mccance, J.A. Nehring, M.L. Commons, J.R. Young, and K.M. Potter
Publication Date: 
2014
Updated Date (text): 
2014-01-02
Parent Publication Title: 
The Wilson Journal of Ornithology
Publication Type: 
Archive number: 
2014/0047 FORT
States: 

Pub Abstract: 
Publication Title: 

Mountain plover nest survival in relation to prairie dog and fire dynamics in shortgrass steppe

Authors: 
Augustine, D.J. and S.K. Skagen
Publication Date: 
2014
Updated Date (text): 
2014-01-02
Parent Publication Title: 
Journal of Wildlife Management
Publication Type: 
Archive number: 
2014/0054 FORT
States: 

Pub Abstract: 

Disturbed xeric grasslands with short, sparse vegetation provide breeding habitat for mountain plovers (Charadrius montanus) across the western Great Plains. Maintaining local disturbance regimes through prairie dog conservation and prescribed fire may contribute to the sustainability of recently declining mountain plover populations, but these management approaches can be controversial. We estimated habitat specific mountain plover densities and nest survival rates on black-tailed prairie dog (Cynomys ludovicianus) colonies and burns in the shortgrass steppe of northeastern Colorado. Mountain plover densities were similar on prairie dog colonies (5.9 birds/km2; 95% CI=4.7–7.4) and sites burned during the preceding dormant season (6.7 birds/km2; 95% CI=4.6–9.6), whereas the 29-day nest survival rate was greater on prairie dog colonies (0.81 in 2011 and 0.39 in 2012) compared to the burned sites (0.64 in 2011 and 0.17 in 2012). Reduced nest survival in 2012 compared to 2011 was associated with higher maximum daily temperatures in 2012, consistent with a previous weather-based model of mountain plover nest survival in the southern Great Plains. Measurements of mountain plover density relative to time since disturbance showed that removal of prairie dog disturbance by sylvatic plague reduced mountain plover density by 70% relative to active prairie dog colonies after 1 year. Plover densities declined at a similar rate (by 78%) at burned sites between the first and second post-burn growing season. Results indicate that black-tailed prairie dog colonies are a particularly important nesting habitat for mountain plovers in the southern Great Plains. In addition, findings suggest that prescribed burning can be a valuable means to create nesting habitat in landscapes where other types of disturbances (such as prairie dog colonies) are limited in distribution and size.

Publication Title: 

Estimates of annual survival, growth, and recruitment of a White-tailed Ptarmigan population in Colorado over 43 years

Authors: 
Wann, G.T., C.L. Aldridge, and C.E. Braun
Publication Date: 
2014
Updated Date (text): 
2014-01-02
Parent Publication Title: 
Population Ecology
Publication Type: 
Archive number: 
2014/0057 FORT
States: 

Pub Abstract: 
Publication Title: 

Drought and cooler temperatures are associated with higher nest survival in Mountain Plovers: summary

Authors: 
Dreitz, V.J. R.Y. Conrey, and S.K. Skagen
Updated Date (text): 
2013-12-30
Parent Publication Title: 
Plains and Prairie Pothole Landscape Conservation Cooperative Website
Publication Type: 
Archive number: 
States: 

Pub Abstract: 
Publication Title: 

Interactive energy atlas for Colorado and New Mexico: an online resource for decisionmakers

Authors: 
Carr, N.B., J. Diffendorfer, S. Hawkins, D. Ignizio, N. Latysh, K. Leib, J. Linard, A.M. Matherne, and N. Babel
Publication Date: 
2013
Updated Date (text): 
2013-05-06
Parent Publication Title: 
U.S. Geological Survey
Publication Type: 
Archive number: 
2013/0100 FORT

Pub Abstract: 

Throughout the western United States, increased demand for energy is driving the rapid development of nonrenewable and renewable energy resources. Resource managers must balance the benefits of energy development with the potential consequences for ecological resources and ecosystem services. To facilitate access to geospatial data related to energy resources, energy infrastructure, and natural resources that may be affected by energy development, the U.S. Geological Survey has developed an online Interactive Energy Atlas (Energy Atlas) for Colorado and New Mexico. The Energy Atlas is designed to meet the needs of varied users who seek information about energy in the western United States. The Energy Atlas has two primary capabilities: a geographic information system (GIS) data viewer and an interactive map gallery. The GIS data viewer allows users to preview and download GIS data related to energy potential and development in Colorado and New Mexico. The interactive map gallery contains a collection of maps that compile and summarize thematically related data layers in a user-friendly format. The maps are dynamic, allowing users to explore data at different resolutions and obtain information about the features being displayed. The Energy Atlas also includes an interactive decision-support tool, which allows users to explore the potential consequences of energy development for species that vary in their sensitivity to disturbance.

Publication Title: 

Hibernacula selection by Townsend's big-eared bat (Corynorhinus townsendii) in Southwestern Colorado

Authors: 
Hayes, M.A., R. Schorr, and K.W. Navo
Publication Date: 
2011
Updated Date (text): 
2013-01-11
Parent Publication Title: 
Journal of Wildlife Management
Publication Type: 
Archive number: 
NONCTR/00388
States: 

Pub Abstract: 
Publication Title: 

Allen's big-eared bat (Idionycteris phyllotis) documented in Colorado based on recordings of its distinctive echolocation call

Authors: 
Hayes, M.A., K.W. Navo, L.R. Bonewell, C.J. Mosch, and R.A. Adams
Publication Date: 
2009
Updated Date (text): 
2013-01-11
Parent Publication Title: 
The Southwestern Naturalist
Publication Type: 
Archive number: 
NONCTR/00386
States: 
Topics: 

Pub Abstract: 
Publication Title: 

Monitoring intensity and patterns of off-highway vehicle (OHV) use in remote areas of the Western USA

Authors: 
Ouren, D.S., and A.W. Coffin
Publication Date: 
2013
Updated Date (text): 
2012-12-11
Parent Publication Title: 
Oecologia Australis
Publication Type: 
Archive number: 
2013/0093 FORT
States: 

Pub Abstract: 

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