Results of plant CNP stoichiometry

Results of chemical analysis to determine the carbon-nitrogen-phosphorus stoichiometry of plant fragments that had not been used in feeding trials. ID [= unique identifier of the record], speciesName [= name of plant species], Replicate [= replicate id within a species], P% [= phosphorus content in % of plant dry mass], C% [= carbon content in % of plant dry mass], N% [= nitrogen content in % of plant dry mass

Results of caterpillar feeding trials

The results of the caterpillar (using Parapoynx stratiotata) feeding trials were conducted in the laboratory in the Netherlands and are located in a tab-separated text file. Respectively, column headings are: ID [= unique identifier of each record], species [= plant species fed upon by caterpillar], fresh biomass (g) [= initial plant mass offered to caterpillar], fresh biomass after (g) [= remaining plant mass], FWeaten (g) [= fresh plant biomass lost during feeding trial], 450nm [= spectrophotometric absorbance at 450 nm after experiment], TON [= oxidized nitrogen in water in mg/L],NH4 [= total ammonium in water in mg/L], PO4 [= o-phosphate in water in mg/L], NO2 [= nitrite in water in mg/L], FW caterpillar end (mg) [= final fresh weight of combined caterpillars in milligrams], P% [= plant phosphorus content in % of plant dry mass of plant remainder after feeding], C% [= plant carbon content in % of plant dry mass of plant remainder after feeding], N% [= plant nitrogen content in % of plant dry mass of plant remainder after feeding], TPC% [= plant total phenolics content in % of plant dry mass of plant remainder after feeding], caterpillar.DM [= caterpillar dry mass after feeding],caterpillar.C [= caterpillar carbon content in % of its dry mass after feeding]caterpillar.N [= caterpillar nitrogen content in % of its dry mass after feeding], caterpillar.P [= caterpillar phosphorus content in % of its dry mass after feeding

Appendix D. A table with the analysis of the effect of herbivore treatments and nutrient availability on biomass of macrophytes and filamentous algae and the C:N and C:P ratio of macrophytes.

A table with the analysis of the effect of herbivore treatments and nutrient availability on biomass of macrophytes and filamentous algae and the C:N and C:P ratio of macrophytes

Appendix E. A figure illustrating the interactive effect of caterpillar presence and nutrient availability on macrophyte biomass.

A figure illustrating the interactive effect of caterpillar presence and nutrient availability on macrophyte biomass

Appendix C. A figure showing the effect of caterpillar presence on snail growth along the gradient of nutrient availability.

A figure showing the effect of caterpillar presence on snail growth along the gradient of nutrient availability

Appendix A. A figure and a table with statistical results for the effect of nutrient availability and herbivore presence on water conditions measured at the end of the experiment.

A figure and a table with statistical results for the effect of nutrient availability and herbivore presence on water conditions measured at the end of the experiment

dataset_exclosures_def

Data on the vegetation in the exclosures placed in riparian vegetation in Dutch fen wetland and the vegetation development over two growing seasons

Appendix A. Additional materials and methods, including a diagram showing the chambers used in the methane flux measurements, photographs of the waterfowl exclosures, and a table showing potential methane oxidation and production, soil moisture content, soil organic matter content, soil density per month in the exclosed and control plots, and the results of a repeated-measures ANOVA for these soil characteristics.

Additional materials and methods, including a diagram showing the chambers used in the methane flux measurements, photographs of the waterfowl exclosures, and a table showing potential methane oxidation and production, soil moisture content, soil organic matter content, soil density per month in the exclosed and control plots, and the results of a repeated-measures ANOVA for these soil characteristics

Predator-prey survival data for native and non-native aquatic plants

Prey survival data was collected in a series of three aquarium experiments. The file is split into two tabs: realplant-survival used for Figure 1 and artificialplant-survival used for Figure 2. The first tab contains data about prey survival under mirror carp or dragonfly larvae predation in monocultures of real aquatic plants, at low and high stem density. The column headings in the first tab are: totalID (distinct ID per record), testSpecies (gives scientific name of plant species tested), preySurvival (%-prey survival), stemDensity (plant stem density), plantOrigin (plant native status in Northwestern Europe), dayExperiment (day that data record was collected in predator-prey trial), periodDay (time of the day that data record was collected in predator-prey trial), preySpecies (type of prey for data record), predatorSpecies (type of predator for data record), predatorIndividual (unique ID for dragonfly individual or unique ID for fish pairs). The second tab contains data about prey survival under mirror carp predation, in monocultures of artificial plant analogues resembling aquatic plants, at low and high stem density. For information on column headings in the second tab, see descriptions given for headings in the first tab. Information on the number of prey at t0, the duration of predation trials, plant density and other ifnormation is provided in the corresponding publication

Data_Sheet_1_Managing Successional Stage Heterogeneity to Maximize Landscape-Wide Biodiversity of Aquatic Vegetation in Ditch Networks.docx

<p>The presence of a high diversity of different successional stages in a landscape may help to conserve and promote landscape-wide biodiversity. A strategy to achieve this is using Cyclic Rejuvenation through Management (CRM), an approach employed in a variety of different ecosystems. CRM periodically resets the successional stages in a landscape. For aquatic systems this constitutes vegetation removal and dredging. For this approach to be useful (a) successional stages are required to be different in community composition and (b) these differences need to be caused by true replacement of species between stages. While potentially valid, these assumptions are not generally tested prior to application of CMR. In this study we test these assumptions to explore the usefulness of managing on successional stage heterogeneity for maximizing landscape-wide aquatic plant diversity. We carried out vegetation surveys in the ditch networks of 21 polder landscapes in Netherlands, each containing 24 ditch reaches. Using a clustering approach combined with insight from literature on vegetation succession in these systems we assigned our sampled communities to defined successional stages. After partitioning landscape diversity into its alpha and beta components, we quantified the relative importance of replacement among successional stages. Next, through scenario analyses based on simulations we studied the effects of reducing successional stage heterogeneity on landscape-wide biodiversity. Results showed that differences in community composition among successional stages were a potentially important factor contributing to landscape diversity. Early successional stages were characterized by higher replacement of species compared to late successional stages. In a scenario of gradual decrease of heterogeneity through the systematic loss of the earliest successional stages we found 20% of the species richness in a polder was lost, pointing toward the importance of maintaining early successional stages in a polder. This makes a compelling case for application of CRM within agricultural drainage ditch landscapes to maximize regional aquatic plant diversity. While applied to drainage ditch systems, our data-driven approach is broadly applicable to other systems and may help in providing first indications of the potential of the CRM approach. We argue that CRM may maintain and promote regional biodiversity without compromising the hydrological function of the systems.</p