Macrosystem Biology of Temperate Steppe Rivers

NSF Macrosystem Biology of Temperate Steppe Rivers

In the fall of 2015, we began a 5-yr study of macrosystem processes in 18 rivers of the temperate steppes of the North American Great Plains and the Temperate Steppes of Mongolia. This study is funded by the Macrosystem Biology program at the National Science Foundation (NSF) under the title: “ Collaborative Research: Hierarchical Functioning of River Macrosystems in Temperate Steppes – From Continental to Hydrogeomorphic Patch Scales.”

This project involves students, technicians, and co-principal investigators from universities in the USA and Mongolia, with one Co-PI from Europe (see the table below).


  Name Grant Status Institution Primary Tasks
Alain Maasri Co-PI Global Nature Fund (Germany) Data management; statistics
Orkhonselenge Alexander Collaborator National University of Mongolia GIS and hydrogeomorphic analyses
Bazartseren Boldgiv Co-PI National University of Mongolia Mongolian Coordination; food webs
Mendsaikhan Bud Collaborator Institute of Geoecology Fish diversity and traits
Chuluunbat Suvdtsetseg Collaborator Mongolian State University of Education Invertebrate trait-based analysis
Dashdondog Narangarvuu Collaborator National University of Mongolia Invertebrate trait-based analysis
Sudeep Chandra Co-PI University of Nevada, Reno U.S. Co-Coordinator; food webs
Clint Davis Post-Doc University of Nevada, Reno System metabolism
Walter Dodds Co-PI Kansas State University System metabolism
Jon Gelhaus Co-PI Drexel Univ. and Acad. of Natural Sciences Invertebrate trait-based analysis
Barbara Hayford Co-PI Wayne State College Invertebrate trait-based analysis
Olaf Jensen Co-PI Rutgers University Fish trait-based analyses
Scott Kenner Co-P.I. South Dakota School of Mines & Technology GIS and hydrogeomorphic analyses
Kelly Kindscher Collaborator University of Kansas Riparian zone analysis
Mark Pyron Co-PI Ball State University Fish diversity and trait-based analysis
Daniel Reuman Co-PI University of Kansas System Modeling
James H. Thorp PI University of Kansas Overall project coordination; food web

analysis; hydrogeomorphic analysis

Jason Tinant Collaborator Oglala Lakota College Coordination of Lakota Student Projects


The current web page: (a) reviews the definition of macrosystem ecology; (b) presents “non-technical” and NSF summaries of the project; (c) describes ongoing and future projects; and (d) eventually provides results of our studies.


Definition of Macrosystem Ecology

A macrosystem can be defined as “… a hierarchically organized, integrated terrestrial, inland aquatic and/or marine ecological unit of large spatial extent (ca. 102 – 106 km2 or more depending on the types and sizes of ecosystems present) whose temporal interactions within the unit and within regional through global processes are especially significant over periods of decades to millennia” (Thorp 2014). Riverine macrosystems have also been described as “…watershed-scale networks of connected and interacting riverine and upland habitat patches” (McCluney et al. 2014). Macrosystem ecology, therefore, can be “…the study of diverse ecological phenomena at the scale of regions to continents and their interactions with phenomena at other scales (Heffernan et al. 2014).

In actual fact, there is a blurry line between ecosystems and macrosystems, but generally speaking the latter is considered larger and could involve multiple ecosystems. Environmental factors such as climate change are particularly important in ecological studies of macrosystems. Studies range from regional, to continental, to inter-continental (in our case).


Heffernan, J.B., P.A. Soranno, M.J. Angilletta, Jr, L.B. Buckley, D.S. Gruner, T.H. Keitt, J.R. Kellner, J.S. Kominoski, A.V. Rocha, J. Xiao, T.K. Harms, S.J. Goring, L.E. Koenig, W.H. McDowell, H. Powell, A.D. Richardson, C.A. Stow, R.. Vargas, and K.C. Weathers. Macrosystems ecology: understanding ecological patterns and processes at continental scales. Frontiers in Ecology and the Environment 12(1): 5-14.

McCluney, K.E., N. L. Poff, M.A. Palmer, J.H. Thorp, G.C. Poole, B.S. Williams, M.R. Williams, and J.S. Baron. 2014. Riverine macrosystems ecology: sensitivity, resistance, and resilience of whole river basins with human alterations. Frontiers in Ecology and the Environment 12(1): 48-58. (DOI: 10.1890/120367 [2013])

Thorp, J.H. 2014. Metamorphosis in river ecology: from reaches to macrosystems. Freshwater Biology 59: 200-210. [On-Line in 2013 as DOI: 10.1111/fwb.12237.]



Project Description

The figure above illustrates the design of this large macrosystem biology project. We will begin sampling three rivers in the semi-arid shrublands in the USA (3 rivers in the Great Basin) in the summer of 2016. I have included below two versions of the project summary for this macrosystem study. The first is a more-or-less, non-technical summary of the project, as requested by NSF. It is followed by a somewhat more technical summary, as included in the original proposal. As we begin gathering information on the rivers in 2016 in the USA (and starting in 2017 in Mongolia), I will add more information to this website.


Non-Technical Summary

The need to understand and manage ecosystems at larger “macrosystem” levels is becoming increasingly crucial with global climate changes and impacts of exotic species in our freshwater rivers and lakes. Macrosystem management requires an understanding of how different levels of spatial complexity (reach to valley scale) and biotic organization (populations to ecosystems) affect the functioning of ecological systems. The present study will provide this information for 18 rivers spread equally between the two largest temperate steppe biomes of the world: the North American Great Plains and the Euro-Asian Steppes (including those in Mongolia). These rivers flow through 3 major types of ecoregions within these temperate steppe biomes: mountain steppe shrublands, short-to-tall grasslands, and semi-arid shrublands. Scientists and students from the USA and Mongolia will sample the structure and functioning of these 18 rivers in a variety of hydrogeomorphic areas, such as constricted, meandering, braided, and anastomosing channel sections. Despite their similarity in biome and ecoregional types, the river macrosystems of the Great Plains and the Mongolian steppes vary substantially in fauna, flora, and community through ecosystem functioning. This results in part because of differences in climatic patterns, the degree of riverine landscape modification (e.g., by dams, levees, and riparian modification), and the naturalness of the resident fauna. For example, most rivers in the USA contain some dams and many exotic fauna have been introduced, while the vast majority of Mongolian rivers contain no dams and their aquatic fauna is almost exclusively natural and different from those in the USA. Moreover, the Central Asian subcontinental area of Mongolia has one of the strongest warming signals on earth, with air temperatures rising three times faster than the overall northern hemisphere average. Consequently, riverine macrosystems in the USA can help predict changes to Mongolian rivers as a result of pending dam construction and possible species introductions to some rivers, while knowledge of responses of Mongolian macrosystems to more rapid climatic changes can help predict future effects in U.S. rivers. Therefore, this project’s goals are to: (a) compare and contrast hierarchical scaling relationships and effects of system drivers and cross-scale interactions on rivers in similar biomes and ecoregions of the two continents; and (b) evaluate effects of climatic changes and anthropogenic disturbance to these river macrosystems. This project will provide research experiences for under-represented participants (particularly rural and Native American students), stimulate STEM program recruitment in largely under-represented (EPSCoR) states, support some faculty and students at primarily undergraduate institutions, and contribute to scientific education at both graduate and undergraduate institutions in two countries.

Original NSF Summary

This macrosystem project focuses on roles of hierarchical scales, system drivers, cross-scale interactions, and changing climates in controlling system metabolism, food webs, and biodiversity traits in rivers of temperate steppe biomes. The 3 primary hypotheses are: (i) hierarchical scaling relationships and effects of system drivers and cross-scale interactions should be the same in riverine macrosystems of temperate steppes on both continents as long as sampling is focused on similar ecoregions, includes similar hydrogeomorphic zones, and is undertaken in the same season under minimal anthropogenic impacts; (ii) macrosystem processes, drivers, and interactions, and both ecosystem function and biodiversity characteristics are more similar among ecoregions of the same type in different continents than they are among ecoregions of different types in the same continent; and (iii) differences in effects of climate change on functioning of temperate steppe rivers are more extreme among continents than are effects of zoogeographic differences. The study encompasses investigations at four hierarchical scales: (a) 2 continents with temperate steppe biomes (North American Great Plains and Euro-Asian Steppes of Mongolia); (b) 3 temperate steppe ecoregions/continent (mountain steppe shrublands, short-to-tall grasslands, and semi-arid shrublands); (c) 3 rivers/ecoregion; and (d) 2 structural types of hydrogeomorphic zones/river at the valley-to-microshed scale (3 single channels + 3 sites with main and side channels/river). A total of 162 sites will be sampled in 3 years. All scientists have worked in temperate steppes, with most having studied both U.S. and Mongolian rivers.

This project contributes to fundamental and applied macrosystem ecology in 4 areas: (1) field tests of macrosystem principles; (2) evaluating intercontinental, climate change effects; (3) testing general river theory on factors controlling large scale ecological variation in space; and (4) assessing impacts on river macrosystems from altered terrestrial landscapes and river channels. By examining scaling effects at 4 hierarchical spatial levels, this project directly tests scaling relationships and effects of drivers and cross-scale interactions for different river structures, ecoregions, and continents. This project both contrasts and complements an alternative NSF project (Macrosystems SCALER) examining the utility of cm- and reach-scale measurements and consumer manipulation experiments. That ongoing (2011-2015) study seeks to comprehend ecosystem characteristics of stream networks in 5 North American biomes. Climate impacts will be evaluated in the proposed study by comparing rivers in similar ecoregions but different continents, one of which (Central Asian subcontinental area of Mongolia) has one of the strongest warming signals on earth with air temperatures rising 3x faster than the overall northern hemisphere average.

This project will provide research experiences for under-represented participants, particularly rural and Native American students, stimulate STEM program recruitment in largely under-represented states in science (EPSCoR states: KS, NE, NV, SD), and support faculty and students at primarily undergraduate institutions (PUI). In addition to training 2 postdocs and 5 grad students, the project strongly focuses on training the next generation of environmental scientists (17+ students) from colleges and high schools, with emphasis on Native American undergraduates (6) from Oglala Lakota College and high school students (5) from the Pyramid Lake Paiute Tribe. The research-focused universities have used existing partnerships to further interactions with the STEM Program Director (now a Collaborator) at Oglala Lakota College. Also, 2 students and a Co-PI from a Nebraska PUI will conduct research and interact with other project students and researchers to gain insights to future careers. This project features close research cooperation with a Mongolian Co-PI, Collaborators, and students (some with previous NSF training). One Collaborator trains high school teachers at a Mongolian university of education and will transfer her experiences to future high school teachers. Finally, public outreach will be promoted via development of an exhibit at the Nevada Discovery Museum (attracting 155,000 visitors/yr), a project website (with real-time expedition reports), and focused symposia at science conferences, journal articles, and a workshop in Mongolia (standard means there to report research and influence governments).

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