Nathan R De Jager

Biography

Education

2008    PhD in Ecology, Evolution, and Behavior with a minor in Conservation Biology

            University of Minnesota, St. Paul Minnesota, USA        

2005    MSc in Biology with a minor in Applied and Computational Mathematics

            University of Minnesota, Duluth, Minnesota, USA        

2001    BA in Biology/Environmental Science

            Northwestern College, Orange City, Iowa, USA

 

I serve as a principal investigator and non-supervisory team leader for landscape ecological studies at the USGS Upper Midwest Environmental Sciences Center, where I have been since 2008. My research group uses a combination of field research and computer modelling to study how ecosystem processes respond to disturbances across large landscapes.

In the floodplain of the Upper Mississippi River, we study how spatial and temporal variation in flooding impacts plant and soil processes. Results from field studies are used to parameterize a spatially explicit simulation model that can be used to better understand and forecast effects of altered hydrological regimes and other disturbances (e.g., emerald ash borer, herbivory by white-tailed deer) on forest succession and nutrient cycling.

At Isle Royale National Park, we study how spatial and temporal variability in browsing by moose impacts plant and soil processes. Results from field studies are used to parameterize a spatially explicit simulation model that can be used to better understand and forecast effects of different moose population dynamics on forest succession in the context of climate change and predation by wolves.

In addition to these two primary study areas, I provide leadership and support for graduate students and other researchers working on a diverse array of topics, most of which require the use of GIS or other modelling approaches to link fine-scale measurements with landscape-scale phenomena. I frequently serve on regional to national scale working groups led by the USGS or other conservation groups and am an associate editor with the Natural Areas Journal.

 

Publications

De Jager, N.R., Rohweder, J.J., Miranda, B.M., Sturtevant, B.R., Fox, T.J. Romanski, M.C. 2017. Modelling moose-forest interactions and associated landscape patterns under different predation scenarios at Isle Royale National Park, USA. Ecological Applications 27: 1317-1337.

De Jager, N.R., Drohan, P.J., Miranda, B.M., Sturtevant, B.R., Stout, S.L., Royo, A.A., Gustafson, E.J., Romanski, M.C. 2017. Simulating ungulate herbivory across forest landscapes: a browsing extension for LANDIS-II. Ecological Modelling. Ecological Modelling 350: 11-29.

Swanson, W., De Jager, N.R., Strauss, E., Thomsen, M. 2017. Effects of flood inundation and invasion by Phalaris arundinacea on nitrogen cycling in an Upper Mississippi River floodplain forest. Ecohydrology DOI: 10.1002/eco.1877

De Jager, N.R. and Rohweder, J.J. 2017. Changes in aquatic vegetation and floodplain land cover in the Upper Mississippi and Illinois rivers (1989-2000-2010). Environmental Monitoring and Assessment 189: 77.

De Jager, N.R. and Houser, J.N. 2016. Patchiness in a large floodplain river: associations among hydrology, nutrients, and fish communities. River Research and Applications. 32: 1915-1926. 

Ries, P., De Jager, N.R., Zigler, S.J., Newton, T.J. 2016. Spatial Patterns of native freshwater mussels in the Upper Mississippi River. Freshwater Science. DOI: 10.1086/686670

Scown, M., Thoms, M. and De Jager, N. R. 2016. 'Measuring spatial pattern in floodplains: A step towards understanding the complexity of floodplain ecosystems'. In: River Science: Research and Applications for the 21st Century. D. J. Gilvear, M. Greenwood, M. Thoms and P. Wood (eds). John Wiley and Sons, UK.

De Jager, N.R., Swanson, W., Strauss, E.A., Thomsen, M.T., Yin, Y. 2015. Flood pulse effects on nitrification in a floodplain forest impacted by deer browsing and invasion by Phalaris arundinacea. Wetlands Ecology and Management. 23:1067-1081.

De Jager, N.R., Rohweder, J.J., Yin, Y., Hoy, E. 2015. The Upper Mississippi River floodscape: spatial patterns of flood inundation and associated plant community distributions.Applied Vegetation Science 19:164-172.

Kreiling, R.M., De Jager, N.R., Swanson, W., Strauss, E.A., Thomsen, M.T. 2015. Effects of flooding on ion exchange rates in an Upper Mississippi River Floodplain Forest impacted by herbivory, invasion, and restoration. Wetlands 35: 1005-1012.

Scown, M., Thoms, M. and De Jager, N. R. 2015. Measuring floodplain spatial patterns using continuous surface metrics at multiple scales. Geomorphology 245:87-101.

Scown, M., Thoms, M. and De Jager, N. R. 2015. Floodplain complexity and surface metrics: influence of scale and geomorphology. Geomorphology 245:102-116.

Cogger, B.J. De Jager, N.R. Thomsen, M. 2014. Winter browse selection by white-tailed deer in bottomland forest restorations of the Upper Mississippi River Valley, USA. Natural Areas Journal. 34:144-153.

De Jager, N.R. and Fox, T.J. 2013. Curve Fit: A pixel-level raster regression tool for mapping landscape patterns. Methods in Ecology and Evolution 4: 789-792.

De Jager, N.R., Cogger, B.J., and Thomsen, M.T. 2013. Interactive effects of flooding and deer browsing on floodplain forest recruitment. Forest Ecology and Management 303:11-19.

Pastor, J. and De Jager, N.R. 2013. Simulated responses of moose populations to browsing-induced changes in plant architecture and forage production. Oikos 122:575-582.

De Jager, N.R. and Houser, J.N. 2012. Variation in water mediated connectivity influences patch distributions of total nitrogen (TN), total phosphorous (TP) and TN:TP ratios in the Upper Mississippi River, USA. Freshwater Science 31: 1254-1272.

De Jager, N.R. 2012. The allometry of community level stem size-density distributions in a floodplain forest. American Journal of Botany 99: 1572-1576.

De Jager, N.R. Thomsen, M.T., Yin, Y. 2012. Threshold effects of flood duration on the vegetation and soils of the Upper Mississippi River floodplain, USA. Forest Ecology and Management 270:135-146.

De Jager, N.R, Rohweder, J.J., and J.C. Nelson. 2011. Past and predicted future changes in the land cover of the Upper Mississippi River floodplain, USA. River Research and Applications. 10.1002/rra.1615

De Jager, N.R. and Rohweder, 2011. Spatial Patterns of aquatic habitat richness in the Upper Mississippi River floodplain, USA. Ecological Indicators 13:275-283.

De Jager, N.R. and Rohweder, J.J. 2011. Spatial scaling of core and dominant forest cover in the Upper Mississippi and Illinois River floodplains, USA. Landscape Ecology 26: 697-708

De Jager, N.R. and Yin, Y. 2010. Temporal changes in spatial patterns of submersed macrophytes in two impounded reaches of the Upper Mississippi River, USA, 1998-2009. River Systems 19:129-141.

De Jager, N.R. and Pastor, J. 2010. Effects of simulated moose browsing on the growth and morphology of Rowan (Sorbus aucuparia). Wildlife Biology 16: 301-307.

De Jager, N.R., Pastor, J., Hodgson, A.L. 2009. Scaling the effects of moose browsing on forage distribution from plant canopies to landscapes. Ecological Monographs, 79: 281-297.

De Jager, N.R. and Pastor, J. 2009. Declines in moose population density at Isle Royale National Park, MI, USA and accompanied changes in landscape patterns. Landscape Ecology 24: 1389-1403.

De Jager, N.R. and Pastor, J. 2008. Effects of moose population density and site productivity on the canopy geometries of birch (Betula pubescens and B. pendula) and Scots pine (Pinus sylvestris). Wildlife Biology 14. 251-262.

Van Dyke, F., B. Darby, S.E. Bowdish, J. D. Schmeling, and N.R. De Jager. 2002. Ecosystem Management and Moose: Creating a Coherent Concept with Functional Management Strategies. Alces 38: 55-72.