Urban streams are impacted by invasion of exotic riparian plants and the accumulation of plastic trash, which alter in-stream litter subsidies, and cause changes that cascade up the aquatic food web. The impacts of these factors on urban streams is poorly understood. We compared decay rates and invertebrate colonizers of 5 litter pack types in 4 urban streams in Victoria, British Columbia, Canada: Native Red alder (Alnus rubra) and Sitka willow (Salix sitchensis), invasive English ivy (Hedera sp.), Himalayan blackberry (Rubus armeniacus) and plastic trash (i.e. Styrofoam (polystyrene (PS)), plastic bag (high-density polyethylene (HDPE)), and Mylar (polyethylene terephthalate (PET). We tested 4 hypotheses: 1) exotic ivy and blackberry leaves would decay more slowly than native leaves; 2) exotic ivy and blackberry leaves would attract fewer and less diverse stream invertebrates than native leaves; 3) plastic trash would decay more slowly than leaves; and, 4) plastic trash would attract fewer and less diverse stream invertebrates than leaves. We found no difference between the leaf litter decay rates, however plastic trash decayed more slowly than leaves. Trash decay rates were faster than reported in marine environments, suggesting that plastic trash removal should be a management priority. Stream invertebrates colonized all pack types equally. We observed significant differences in litter decay rates and invertebrate assemblage alpha and Shannon–Wiener diversities across the 4 streams - likely related to differences in stream-specific environmental attributes including flashiness, stream discharge, and biological decay. We conclude that site-specific decay forces supersede litter quality in Pacific Coast urban streams.
Kennedy and El-Sabaawi - Decay patterns of invasive plants and plastic trash in urban streams - R code and Data
Appendix Supplement A2 - R Code and Data from: Kennedy KTM & El-Sabaawi RW. 2018 Decay patterns of invasive plants and plastic trash in urban streams -Urban Ecosystems. This data was collected in urban streams in Victoria, BC, Canada and analysed using R version 3.2.5 (2016-04-14) -- "Very, Very Secure Dishes". The following details the Excel workbook contents for each tab and heading descriptions for the data in each tab. Read Me tab - the description of the data. ### Section 1: Tabs for Leaf Decay Comparisons by Stream and Type data and R code. R Code for Leaf decay k kdd tab - The R code used to compare leaf decay k and kdd by stream and by lead type, and draw plots of Leaf toughness by type and Leaf LMA by type - (copy into a new R script for use).kkcalcdd tab - the kkcalcdd dataset (save as .csv for use with R code). kkcalcddnov042015GRAPH tab - the kkcalcddnov042015GRAPH dataset (save as .csv for use with R code). kkcalcddnov042015 tab - the kkcalcddnov042015 dataset (save as .csv for use with R code). kkcalcnov52015noT0notrash tab - the kkcalcnov52015noT0notrash dataset (save as .csv for use with R code). The kkcalcdd tab, kkcalcddnov042015GRAPH tab, kkcalcddnov042015 tab, and kkcalcnov52015noT0notrash tab all have the same column headings:entry - database entry number; stream - Stream site; subsite - subsite at stream; week - week code; timeelapsed - time elapsed in days; type - litter type; pack - pack number; inmass - initial mass in grams; finmass - final mass in grams; inif - (initial mass - final mass); neglnmr - the negative ln of inif; time - time elapsed in days; dd - degree days elapsed; k - the decay rate k; kdd - the decay rate in kdd.### Section 2: Tabs for Leaf Toughness and Leaf LMA Comparisons data and R code: R Code for Leaf Toughness LMA tab - The R code used to compare leaf toughness and leaf mass per area, and draw plots of Leaf toughness by type and Leaf LMA by type - (copy into a new R script for use). LeafToughKW tab - the LeafToughKW dataset (save as .csv for use with R code). The LeafToughKW tab column headings: id - the sample id number; type - the type of leaf; tough - the leaf samples' toughness in g/mm2 as measured with a penetrometer. LeafLMAKW tab - the LeafLMAKW dataset (save as .csv for use with R code). The LeafLMAKW tab column headings: id - the sample id number; type - the type of leaf; LMA - the leaf samples' Leaf Mass per Area (LMA) in mg/cm2. ### Section 3: Tabs for Invertebrate DCA Ordination, Bayesian Clustering, and Ordination Plot data and R code. R Code for Invert ordination tab - The R code used for the invertebrate DCA Ordination, Bayesian Clustering, and ordination plot and by litter type - (copy into a new R script for use). sy2 tab - the sy2 dataset (save as .csv for use with R code). sy2 tab - column headings: id - pack identifier; Chironomidae - Hellinger transformed counts of Chironomidae; Dugesiidae - Hellinger transformed counts of Dugesiidae; Hirudinea - Hellinger transformed counts of Hirudinea; Psychodidae - Hellinger transformed counts of Psychodidae; Crangonyx - Hellinger transformed counts of Crangonyx; Nemetoda - Hellinger transformed counts of Nemetoda; Lepidostomatidae - Hellinger transformed counts of Lepidostomatidae; Nemouridae - Hellinger transformed counts of Nemouridae; Chloroperlidae - Hellinger transformed counts of Chloroperlidae; Copepoda - Hellinger transformed counts of Copepoda; Dixidae - Hellinger transformed counts of Dixidae; Physidae - Hellinger transformed counts of Physidae. dcasy2scores tab - the dcasy2scores dataset (save as .csv for use with R code). dcasy2scores tab - column headings: pack - pack identifier; DCA1 - DCA 1st axis coordinate; DCA2 - DCA 2nd axis coordinate; marker - pack marker ( first letter = stream, second letter = type). dcasy2invertvectors tab - the dcasy2invert vectors dataset (save as .csv for use with R code). dcasy2invertvectors tab - column headings: species - invertebrate species; DCA1 - DCA 1st axis coordinate; DCA2 - DCA 2nd axis coordinate; DCA3 - DCA 3rd axis coordinate; DCA4 - DCA 4th axis coordinate; totals - DCA totals; marker - invertebrate species marker; ### Section 4: Tabs for invertebrate diversity Comparisons by Stream and Type data and R code. R Code for Invert alpha Shannon tab - The R code used to compare invertebrate alpha diversity and Shannon diversity by stream and by litter type, and draw plots of invertebrate alpha and Shannon diversity by stream and litter type - (copy into a new R script for use). Fall bug Diversity FINAL tab - the Fall bug Diversity FINAL dataset (save as .csv for use with R code). The Fall bug Diversity FINAL tab column headings: id - invertebrate sample ID number; pack - pack number; sdiv - Shannon diversity; fisha - Fisher's alpha; adiv - alpha diversity; indiv - number of individuals; stream – stream; type - litter type; lnindiv1 - ln(indiv +1); lnadiv1 - ln(adiv +1); lnsdiv1 - ln(sdiv +1). Fall bug Diversity tab - the Fall bug Diversity dataset (save as .csv for use with R code). The Fall bug Diversity tab column headings: id - invertebrate sample ID number; pack - pack number; sdiv - Shannon diversity; fisha - Fisher's alpha; adiv - alpha diversity; indiv - number of individuals; stream – stream; type - litter type; ### Section 5: Raw invertebrate count data tab - Our complete week 2 invertebrate count dataset prior to constraint for ordination. Raw invertebrate count data tab column headings: Entry #- data entry number; Pack – pack number; Id - pack identifier; stream – stream identifier, Type – pack type; fraction – fraction of pack identified; Counts of individuals: Chironomidae; Dugesiidae; Oligochaeta; Hirudinea; Psychodidae; Crangonyx; Nemetoda; Lepidostomatidae; Nemouridae; Chloroperlidae; Limnephilidae; Copepoda; Hydridae; Dixidae; Elmidae; Heptageniidae; Simuliidae; Physidae; Planorbidae; Ancylidae; Sphaeriidae; Hydrobiidae; Valvatidae; Lymnaeidae; Rhyacophilidae; Daphniidae; Athericidae; Ceratopogonidae; Astacidae; Tipulidae; Ptychopteridae; Dolichopodidae; Empididae; Stratiomyidae; Tabanidae; Phryganeidae; Coenagrionidae; Aeshnidae; Malacostraca; Sialidae; All individuals – sum of all individuals in the pack (sum formula); # of groups – sum of groups in the pack; All individuals - sum of all individuals in the pack (absolute value); individuals/groups (number of individuals divided by number of groups).
2018-04-28-KennedyAndElSabaawiDecayPatternsOfInvasivePlantsAndPlasticTrashInUrbanStreams-RCodeAndData.xlsx
