Geology topics

Boris C. Kondratieff

Publications and source records attributed to Boris C. Kondratieff.

7 recordsLinked to original sources

USGS2019

Designing flows to enhance ecosystem functioning in heavily altered rivers

More than a century of dam construction and water development in the western United States has led to extensive ecological alteration of rivers. Growing interest in improving river function is compelling practitioners to consider ecological restoration when managing dams and water extraction. We developed an Ecological Response Model (ERM) for the Cache la Poudre River, northern Colorado, USA, to illuminate effects of current and possible future water management and climate change. We used empirical data and modeled interactions among multiple ecosystem components to capture system-wide insights not possible with the unintegrated models commonly used in environmental assessments. The ERM results showed additional flow regime modification would further alter the structure and function of Poudre River aquatic and riparian ecosystems due to multiple and interacting stressors. Model predictions illustrated that specific peak flow magnitudes in spring and early summer are critical for substrate mobilization, dynamic channel morphology, and overbank flows, with strong subsequent effects on instream and riparian biota that varied seasonally and spatially, allowing exploration of nuanced management scenarios. Instream biological indicators benefitted from higher and more stable base flows and high peak flows, but stable base flows with low peak flows were only half as effective to increase indicators. Improving base flows while reducing peak flows, as currently proposed for the Cache la Poudre River, would further reduce ecosystem function. Modeling showed that even presently depleted annual flow volumes can achieve substantially different ecological outcomes in designed flow scenarios, while still supporting social demands. Model predictions demonstrated that implementing designed flows in a natural pattern, with attention to base and peak flows, may be needed to preserve or improve ecosystem function of the Poudre River. Improved regulatory policies would include preservation of ecosystem-level, flow-related processes and adaptive management when water development projects are considered.

Colorado↗

USGS2019

Mismatches between breeding phenology and resource abundance of resident alpine ptarmigan negatively affect chick survival

1. Phenological mismatches – defined here as the difference in reproductive timing of an individual relative to the availability of its food resources – occur in many avian species. Mistiming breeding activities in environments with constrained breeding windows may have severe fitness costs due to reduced opportunities for repeated breeding attempts. Therefore, species occurring in alpine environments may be particularly vulnerable. 2. We studied fitness consequences of timing of breeding in an alpine-endemic species, the white-tailed ptarmigan ( Lagopus leucura ), to investigate its influence on chick survival. We estimated phenological mismatch by measuring plant and arthropods used by ptarmigan in relation to their timing of breeding. 3. We monitored 120 nests and 67 broods over a three-year period (2013–2015) at three alpine study sites in the Rocky Mountains of Colorado. During this same period we actively monitored food resource abundance in brood-use areas to develop year and site specific resource phenology curves. We developed several mismatch indices from these curves that were then fit as covariates in mark-recapture chick survival models. 4. A correlation analysis between seasonal changes in arthropod and food plant abundance indicated that a normalized difference vegetation index (NDVI) was likely the best predictor for food available to hens and chicks. A survival model that included an interaction between NDVI mismatch and chick age received strong support and indicated young chicks were more susceptible to mismatch than older chicks. 5. We provide evidence that individual females of a resident alpine species can be negatively affected by phenological mismatch. Our study focused on individual females and did not examine if phenological mismatch was present at the population level. Future work in animal populations occurring in mountain systems focusing on a combination of both individual- and population- level metrics of mismatch will be beneficial.

Ecology and Evolution↗

USGS2017

A rare and cryptic endemic of the Central Rocky Mountains, U.S.A: The distribution of the Arapahoe snowfly, Arsapnia arapahoe (Nelson & Kondratieff, 1988) (Plecoptera: Capniidae)

The Arapahoe snowfly, Arsapnia arapahoe (Nelson & Kondratieff, 1988) (Plecoptera: Capniidae) is a candidate species warranted for listing under the Endangered Species Act. Prior to this study, A. arapahoe was known from only two tributaries of the Cache la Poudre River in Larimer County, Colorado: Young Gulch and Elkhorn Creek. The objectives of this study were to determine the distribution of this endemic stonefly, and to identify sympatric species as possible surrogate indicators of its occurrence. Eighty-four streams were sampled within the expected geographical range and emergence time-period from 2013 to 2017. Adults of A. arapahoe were discovered in 19 first-, second-, and fourth-order streams beyond the original type localities tributary to the Cache la Poudre River. The new and recently recorded localities were discovered in the Big Thompson River, St. Vrain River, Boulder Creek, and Upper South Platte River Watersheds. Two species, A. decepta (Banks, 1897) and Capnia gracilaria Claassen, 1924, always co-occurred with A. arapahoe , suggesting this species pair may serve as a surrogate indicator of suitable stream habitat for A. arapahoe . Suggestions for future investigation into the distribution, life-history, and habitat of A. arapahoe are presented to aid the conservation of this rare and endemic Colorado stonefly.

Colorado↗

USGS2014

An ecological response model for the Cache la Poudre River through Fort Collins

The Poudre River Ecological Response Model (ERM) is a collaborative effort initiated by the City of Fort Collins and a team of nine river scientists to provide the City with a tool to improve its understanding of the past, present, and likely future conditions of the Cache la Poudre River ecosystem. The overall ecosystem condition is described through the measurement of key ecological indicators such as shape and character of the stream channel and banks, streamside plant communities and floodplain wetlands, aquatic vegetation and insects, and fishes, both coolwater trout and warmwater native species. The 13- mile-long study area of the Poudre River flows through Fort Collins, Colorado, and is located in an ecological transition zone between the upstream, cold-water, steep-gradient system in the Front Range of the Southern Rocky Mountains and the downstream, warm-water, low-gradient reach in the Colorado high plains. The City wanted to better understand the ecological response of the Poudre River ecosystem to potential changes in stream flow and other physical parameters through the conceptual framework of a multivariable integrated model. This goal was met through the use of a probabilistic model based on Bayesian concepts. This construct allowed the integration of a wide range of data and expert opinion (as informed by local data) to predict potential changes to ecosystem conditions under various flow scenarios. Nine flow scenarios representing past, present, and possible future hydrology were developed as the primary model input. Both reach-scale drivers such as stream channel conditions and pollutant loads, as well as ecological conditions, including species composition, interactions, and habitat requirements influenced model-predicted ecosystem outcomes. Model output consisted of probability distributions for eight ecological indicators collectively representing the physical setting, aquatic life, and riparian habitats of the river ecosystem. We are confident in model predictions related to probable trends, relative magnitude of changes and potential ecosystem responses to changing flow conditions, though data availability and the process of converting diverse data types into a common unit (probabilities) limit precision of individual results. Key findings suggest that: The present ecological function of the Poudre River is altered as a result of more than 150 years of human influences that include highly managed flows, urbanization, gravel mining, channelization and urban and industrial encroachment in the floodplain, underscoring the vulnerable and complex character of the Poudre River; A continuation of today’s flow management will lead to ongoing changes in ecosystem condition, and additional water depletions will compromise ecological conditions; High flows play an essential role in maintaining and improving the aquatic and riparian condition of the river; Adequate flows in base-flow periods are critical to desirable water quality, and thriving fish and insect populations; Improvement of native aquatic life is possible if issues related to channel modifications, siltation, invasive species, and base and high flow conditions are managed properly; The present confined river channel and modified flows has reduced the potential for a keystone and iconic species, plains cottonwood, to be self-sustaining in the study area; The streamside corridor retains the potential to support a functioning riparian forest that provides important ecological services if periodic floodplain inundation occurs. Environmental flows that combine stable and adequate flows in base-flow periods with occasional rejuvenating high flows that meet target levels defined in this study are likely improve all biological indicators across the system. ERM test scenarios that include both stable base flows and rejuvenating high flows indicate that substantial improvements in the river ecosystem can be achieved with improved management of flow volumes similar to those observed in the river during the last half century of intensive water development. These results underscore the possibility of improving the river ecosystem through active management while still maintaining the Poudre’s diverse economic benefits and role as a working river. The ERM was designed to represent the multi-dimensional ecological character of the contemporary urban Poudre River. It provides a scientific foundation that can serve as a decision support tool and foster a more informed community discussion about the future of the river as it provides a better understanding of the likely response of the Poudre River ecosystem to environmental flow management and other stewardship activities. In particular, model results can assist managers in developing specific management actions to achieve desirable goals for key indicators of river health.

Colorado↗

USGS2012

Diversity and distribution of mayflies (Ephemeroptera), stoneflies (Plecoptera), and caddisflies (Trichoptera) of the South Platte River Basin, Colorado, Nebraska, and Wyoming, 1873-2010

The U.S. Geological Survey, in cooperation with the C.P. Gillette Museum of Arthropod Diversity (Colorado State University, Fort Collins, Colorado), compiled collection record data to document the historical and present-day occurrence of mayfly, stonefly, and caddisfly species in the South Platte River Basin. Data were compiled from records collected between 1873 and 2010 to identify where regional knowledge about species occurrence in the basin is lacking and to encourage future researchers to locate additional populations of these poorly understood but very important organisms. This report provides a description of how data were compiled, a map of approximate collection locations, a listing of the most recent collection records from unique locations, general remarks for each species, a species list with selected summary information, and distribution maps of species collection records.

Colorado;Nebraska;Wyoming↗

USGS2006

An annotated list of the mayflies, stoneflies, and caddisflies of the Sand Creek basin, Great Sand Dunes National Park and Preserve, Colorado, 2004 and 2005

The U.S. Geological Survey, in conjunction with the Great Sand Dunes National Park and Preserve and its cooperators, did an extensive inventory of certain targeted aquatic-insect groups in the Sand Creek Basin, Great Sand Dunes National Park and Preserve, to establish a species list for future monitoring efforts. Study sites were established to monitor these groups following disturbance events. Such potential disturbances may include, but are not limited to, chemical treatment of perennial stream reaches to remove nonnative fishes and the subsequent reintroduction of native fish species, increased public use of backcountry habitat (such as hiking and fishing), and natural disturbances such as fire. This report is an annotated list of the mayflies, stoneflies, and caddisflies found in the Sand Creek Basin, Great Sand Dunes National Park and Preserve, 2004 and 2005. The primary objective of the study was to qualitatively inventory target aquatic-insect groups in perennial streams, and selected unique standing-water habitats, such as springs, and wetlands associated with the Sand Creek Basin. Efforts focused on documenting the presence of aquatic-insect species within the following taxonomic groups: Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies). These insect orders were chosen because published species accounts, geographic distribution, and identification keys exist for many Colorado species. Given the extent of available information for these groups, there existed a potential for identifying new species and documenting range extensions of known species.

Data Series↗

USGS2006

A database of lotic invertebrate traits for North America

The assessment and study of stream communities may be enhanced if functional characteristics such as life-history, habitat preference, and reproductive strategy were more widely available for specific taxa. Species traits can be used to develop these functional indicators because many traits directly link functional roles of organisms with controlling environmental factors (for example, flow, substratum, temperature). In addition, some functional traits may not be constrained by taxonomy and are thus applicable at multiple spatial scales. Unfortunately, a comprehensive summary of traits for North American invertebrate taxa does not exist. Consequently, the U.S. Geological Survey's National Water-Quality Assessment Program in cooperation with Colorado State University compiled a database of traits for North American invertebrates. A total of 14,127 records for over 2,200 species, 1,165 genera, and 249 families have been entered into the database from 967 publications, texts and reports. Quality-assurance procedures indicated error rates of less than 3 percent in the data entry process. Species trait information was most complete for insect taxa. Traits describing resource acquisition and habitat preferences were most frequently reported, whereas those describing physiological tolerances and reproductive biology were the least frequently reported in the literature. The database is not exhaustive of the literature for North American invertebrates and is biased towards aquatic insects, but it represents a first attempt to compile traits in a web-accessible database. This report describes the database and discusses important decisions necessary for identifying ecologically relevant, environmentally sensitive, non-redundant, and statistically tractable traits for use in bioassessment programs.

Data Series↗