CWM_traits for aquatic plants

Data was collected in a field survey in August 2014 comprising 30 sites in the Gulf of Finland, Northern Baltic Sea. Sampled sites occurred along a wave exposure gradient and were divided into outer, middle and inner archipelago areas (see article for details). At each site, five replicate plots (1m2 each) were sampled. Trait measurements were weighted by the shoot densities of each species to retrieve the community-weighted mean trait value and standardized to have a mean of 0 and variance of 1. See article for more information on the trait measurements. The data was used in constructing Structural Equation Models. Abbreviated headlines are as follow: “CWM_SLA” = community-weighted mean specific leaf area, “CWM_Root” = community-weighted mean root length, “CWM_Hmax” = community-weighted mean maximum vegetative height, “CWM_RS = community-weighted mean root to shoot ratio, CWM_LeafN = community-weighted mean leaf nitrogen concentration, “CWM_RootN” = community-weighted root nitrogen concentration, “CWM_Leafd15N” = the community-weighted mean delta 15N of youngest leaves, “CWM_Leafd13C” = the community-weighted mean delta 13C of youngest leaves, “CWM_Rootd15N” = the community-weighted mean delta 15N of youngest roots, “lnSilt” = the ln-transformed silt-fraction and “lnPrimprod” = the ln-transformed community primary production

Results of the GLMM (Poisson error distribution, log link function and replicate identity as a random factor).

<p>Effects of pH treatment and time on larval abundance.</p><p>All two-way interactions between time and pH treatment were significant and are denoted in bold.</p

Mean pH levels during the experiment.

<p>Measured from all replicate bottles (n = 5) in each treatment. For clarity SD are not shown.</p

Indication of shell dissolution in different pH treatments.

<p>The left picture shows the situation after the 20-day experiment in control conditions, picturing several empty shells of <i>M. balthica</i> larvae. The right picture is from the pH_7.2 at the same time point, with the majority of the dead shells absent, implying a high dissolution of the shell material in low pH conditions.</p

Larval abundance in different pH treatments over time.

<p>The relationship between logarithmic larval abundance and time for four different pH treatments. Lines were plotted using coefficients from the GLMM. The first two sampling points were on days 3 and 6, after which the larval sampling was conducted every other day. Each replicate (n = 20) for each sampling point is shown.</p

Larval sizes at the start and end of the experiment in different pH treatments.

<p>Mean ±SD, n = 105.</p

Larval sizes at the end of the 20-day experiment in different pH treatments.

<p>Larval sizes are illustrated as size frequency distributions in pH treatments (A) 7.2, (B) 7.4, (C) 7.7 and (D) 8.1, and presented with mode values illustrating the increase of large size fractions in the control treatment.</p

Appendix D. Disturbance-induced changes in the macrofaunal community.

Disturbance-induced changes in the macrofaunal community

Changes in sediment nutrient fluxes due to increasing duration of hypoxia.

<p>The graphs show the average flux (± SE, N = 4) of (A) O₂ (B) Si (C) NH₄⁺ (D) NO₃⁻ + NO₂⁻, (E) PO₄³⁻ and (F) Fe²⁺ for each treatment.</p

Appendix B. Description of sediment properties at the experiment site.

Description of sediment properties at the experiment site