Uncovering relationships between landscape diversity and species interactions is crucial for predicting how ongoing land-use change and homogenization will impact the stability and persistence of communities. However, such connections have rarely been quantified in nature. We coupled high-resolution river sonar imaging with annualized energetic food webs to quantify relationships between habitat diversity, energy flux, and trophic interaction strengths in large-river food web modules that support the endangered Pallid Sturgeon. Our results demonstrate a clear relationship between habitat diversity and species interaction strengths, with more diverse foraging landscapes containing higher production of prey and a greater proportion of weak and potentially stabilizing interactions. Additionally, rare patches of large and relatively stable river sediments intensified these effects and further reduced interaction strengths by increasing prey diversity. Our findings highlight the importance of landscape characteristics in promoting stabilizing food-web architectures and provide direct relevance for future management of imperiled species in a simplified and rapidly changing world.

This dataset contains habitat information from the Missouri River that was collected in 2013-2014 via side scan sonar, geoprocessed in ArcMap, and organized and analyzed in Microsoft Excel and R. Additionally, 25-30 invertebrate samples were collected from the Missouri River throughout the year from a wide variety of habitats in 2014-2015. More specifically, the methods used to quantitatively sample invertebrate communities were as follows: main-channel sand habitat: a Ponar dredge sampler (0.052 m²) attached to a sounding reel on a boat; cobble/gravel: a Hess sampler (0.086 m²); wood: 250 μm mesh bags and scrubbed; depositional off-channels: a stovepipe core (0.031 m²); and large boulders: scrubbed in buckets while a D-frame dip net was held downstream. Samples were preserved with buffered formalin and rinsed onto nested sieves (1 mm and 250 um) in the laboratory. Invertebrates were enumerated and measured to the nearest mm to estimate abundance, biomass, and secondary production. Movement data of Pallid Sturgeon were collected from 2003-2013 by a variety of state and federal agencieis. These data were used to estimate foraging distance (river km) by calculating the distance between tagging and recapture events. Pallid and Shovelnose sturgeon abundance (inidividuals/m2), biomass (g AFDM/m2), and size structure were estimated from mark-recapture efforts on the Missouri River in 2014 and these data were used to esimate secondary production (g AFDM/m2/year) of sturgeon. Sturgeon diets were collected using trammel netting and gastric lavage in 2013-2014. Diets were processed similarly to benthic invertebrates and identified, measured, and counted under a microsope. Together these data are used to estimate annual consumption and trophic basis of production of sturgeon, and construct food web modules to estiamte trophic interaction strengths. Additionally, these data are used with the habitat information described above to relate properties in the physical habitat templet to the strengths and patterning of trophic interactions. 

Microsoft Excel, Microsoft Word, R