DOI: 10.5061/dryad.p5hqbzkwk
title: Nutrients from spawning salmon influence leaf area, tissue density, and nitrogen-15 in riparian plant leaves

description: Nutrient subsidies have significant impacts on ecosystems by connecting
 disjunct habitats, often through long distance animal migrations. Salmon
 migrations on the North Pacific coasts provide these kinds of nutrient
 subsidies from senescent fish at the end of their life cycle, which can
 have significant ecological effects on terrestrial species. This can
 include impacts on individuals, populations, and communities, where shifts
 in community composition towards nitrophilic plant species have been
 documented. We investigated the effects of variation in salmon spawning
 density on the leaf traits of four common riparian plant species on the
 central coast of British Columbia, Canada. We found that all plant species
 had higher foliar salmon-derived nitrogen on streams with a higher
 spawning density. Three of the four species had larger leaves, and one
 species also had higher leaf mass per area on streams with more salmon.
 However, we found no differences in leaf greenness or foliar percent
 nitrogen among our study streams. These results demonstrate that nutrient
 subsidies from spawning salmon can have significant impacts on the
 ecology, morphology, and physiology of riparian plants, which lends
 support to a mechanism by which certain plants are more common on
 productive salmon streams. Our findings therefore have broader
 implications for salmon ecosystems.
description: # Nutrients from spawning salmon influence leaf area, tissue density, and
 nitrogen-15 in riparian plant leaves
 [https://doi.org/10.5061/dryad.p5hqbzkwk](https://doi.org/10.5061/dryad.p5hqbzkwk) This data set is associated with the collection of field and lab data on riparian plant traits in Haíɫzaqv Territory on the Central Coast of British Columbia, Canada. Leaves from multiple species of riparian were collected from 14 different salmon-bearing rivers that vary in spawner abundance. Within the 14 different rivers, we used a stratified random sampling approach to collect leaf samples from these plants across four different reaches, or strata, and four different sites within each strata (up to 16 sites per stream). These leaf samples were collected from within multiple quadrats at each site. The leaves were measured for leaf nitrogen-15, percent nitrogen, leaf mass per area, leaf greenness, and leaf area. Several environmental covariates at the site of field collection were also measured. This study confirmed thatriparian plants appear to integrate salmon-derived nitrogen into their foliar tissues, and may grow larger leaves on streams with more abundant salmon runs. We also found that one species of plant had increased leaf tissue density on streams with more spawning salmon. ## Description of the data and file structure * Description: A comma-delimited file containing plant trait data from plant leaves collected from riparian areas along salmon streams. * Format(s): .csv * Missing Data Codes: NA * Dimensions: 1002 rows x 24 columns * Variables: * date: the date that the leaf samples were collected (DD-MM-YY) * stream: the name of the stream where the samples were collected * quadrat.id: the unique sample quadrat identifier which consists of the stream name, the reach (or strata) number, the site within the strata (A-D), and the quadrat number within the site (1-4) * species: a four-letter species code denoting the plant species that the leaf was collected from; MADI (*Maianthemum dilatatum*), RUSP (*Rubus spectabilis*), MEFE (Menziesia ferruginea), VASP (*Vaccinium* spp.), and TITR (*Tiarella trifoliata*, which was excluded from analysis) * sample.id: the unique sample identified created by adding the species code to the quadrat id * salmon.density: the total density of salmon in kilograms per metre of stream * chum.density: the total density of chum salmon in kilograms per metre of stream * pink.density: the total density of pink salmon in kilograms per metre of stream * dist.upstream: the distance (m) that the sample quadrat was upstream from the river mouth * dist.from.stream: the distance (m) that the sample quadrat was away from the streambank * slope: the slope of the quadrat in degrees * avg.canopy.cover: the average canopy cover (%) over the quadrat * avg.soil.moisture: the average soil moisture within each quadrat * ref.soil.moisture: the average soil moisture at a consistent reference site to control for the effect of precipitation * punch.weight.mg: the weight (mg) of a singular punch of each leaf * image.id: the unique image identifier for each leaf that was used in ImageJ * leaf.area: the leaf area (cm squared) measured using ImageJ * rMean: the mean value of the red colour channel in the leaf image * gMean: the mean value of the green colour channel in the leaf image * bMean: the mean value of the green colour channel in the leaf image * percent.green: the proportion of the green colour channel value when compared to the sum of all three colour channel values * n.15: the amount of the nitrogen-15 isotope present in the leaf sample, presented in parts per thousand or units per mil (‰) after elemental analysis. * total.n.ug: the total mount of nitrogen present in the leaf sample, presented in micrograms (μg) after elemental analysis. * sample.weight.mg: the weight of the ground isotope sample in milligrams (mg) prior to elemental analysis. ## Sharing/Access information These data were generated by the study's co-authors and not derived from another source. Link to other publicly accessible locations of the data and associated code for analysis: * [https://github.com/adennert/salmon-leaf-traits](https://github.com/adennert/salmon-leaf-traits)