DOI: 10.5061/dryad.4tmpg4fg4
title: Data from: Invasive submerged plant has a stronger inhibitory effect on epiphytic algae than native plant

description: The invasion of submerged aquatic plants potentially results in a loss of
 native biodiversity in these ecosystems. There has been little attention
 paid to the impact of invasive submerged plants on epiphytic algal
 communities. We conducted a 30-day outdoor mesocosm experiment on the
 shore of subtropical Lake Liangzihu, China, to investigate the effects of
 two submerged plant species, an invasive species (Elodea nuttallii) and a
 native species (Hydrilla verticillata), on epiphytic algal communities. We
 also explored the relationship between macrophyte secondary metabolites
 and epiphytic algae by conducting a laboratory cultivation experiment. We
 give the raw dataste, including the specie data of abundance, epiphytic
 algal communities traits, and environmental parameters in the outdoor
 mesocosm experiment and laboratory cultivation experiment, and also
 including the data of plant traits.
description: Water samples were collected
 from a depth of 50 cm in all 15 ponds on the 10<sup>th</sup>,
 20<sup>th</sup>, and 30<sup>th</sup> day of the
 study period. Water temperature (T), dissolved oxygen (DO), pH, turbidity
 (Turb), and chlorophyll a concentration (Chl-a) were measured using a
 handheld multi-parameter water analyzer (HYDROLAB HL7, HACH, USA) during
 field tests. Moreover, we collected 1 L water samples at 50 cm depth from
 each pond for chemical analysis and immediately stored them on ice. Total
 nitrogen (TN) and total phosphorus (TP) were analyzed using a flow
 injection analyzer (QC8500, LACHAT, USA), and dissolved inorganic carbon
 (DIC) was measured using a total organic carbon analyzer (TOC-L, SHIMADZU,
 Japan). At the time of measurement, 50 leaves
 of <em>Hydrilla verticillata</em>, <em>Elodea
 nuttallii</em>, and a plant with bionic properties were carefully
 selected to ensure uniformity in growth state or size before placing them
 in a wide-mouth plastic bottle with 100 mL of pure water in the respective
 pond. Epiphytic algae were removed by a soft bristle brush in water
 (Foerster and Jr, 1965), and the leaf area (LA) was measured using an area
 meter (LI-3100C, LI-COR, USA) after selection. The 200 mL water samples
 were split into duplicates, with one piece fixed to 1 mL Lugol's
 solution for later analysis and another used to determine the maximum
 quantum efficiency (<em>F</em>v/<em>F</em>m) of
 Photosystem II and Chl-a concentration. The maximum quantum efficiency of
 Photosystem II of epiphytic algae was determined by Pulse Amplitude
 Modulation (PAM) fluorometry using a Microscopy Pulse-Amplitude-Modulated
 fluorometer (Microscopy-PAM, Walz, Germany) (Kottuparambil and Agusti,
 2020). The Chl-a concentration of epiphytic algae was determined using a
 chlorophyll a fluorometer (HYDROLAB MS5, HACH, USA) and used as a
 surrogate for epiphytic algae biomass  (Yang et al., 2020). The biomass of
 epiphytic algae (<em>m</em>) was calculated using the
 following formula: The fixed sample of epiphytic algae was subjected to
 centrifugation at 2000 rpm for 10 minutes, and the supernatant was
 discarded. The volume was then adjusted to 30 mL and mixed thoroughly. The
 number and species of epiphytic algae were enumerated using a counting
 plate at 400× magnification under an optical microscope (BX53+DP74,
 OLYMPUS, Japan). For each sample, 50 microscopic fields of vision were
 examined and counted based on established protocols (Hu and Wei, 2006;
 Effiong and Inyang, 2015; Qian et al., 2015). Species richness
 (<em>S</em>) was quantified as the total number of different
 species present in the sample, while abundance (<em>N</em>,
 cells·mm<sup>-2</sup>) was calculated as the total number of
 individual cells using the formula:
 Prior to the measurements, the
 maximum quantum efficiency
 (<em>F</em>v/<em>F</em>m) of Photosystem II in the
 dark was determined using a Diving-PAM fluorometer (DIVING-PAM II, Walz,
 Germany) (Xu et al., 2018). At the time of measurement, the number of
 plants in each pond was counted. Plant length was determined for twenty
 randomly selected plants, while the dry weight of fifty plants within each
 quadrat was determined by drying at 60°C for &gt;48 h. To calculate
 the biomass of each plant in the corresponding pond, the dry weight was
 multiplied by the number of plants and divided by
 50. Afterwards, 1.0 g of fresh plant sample was
 accurately weighed from each pond for extraction of organic compounds.
 Organic compounds were extracted by successive extraction from a 1.0 g
 sample using methanol and a Soxhlet extractor, following the method
 described by Fileto-Perez et al. (Fileto-Perez et al., 2015). The methanol
 extract was fixed to a volume of 10 mL and analyzed by GC-MS (GCMS-QP
 2020NX, SHIMADZU, Japan). The GC injector temperature was set to 220 °C,
 and the oven temperature was maintained at 40 °C for 3 min before being
 increased from 40 °C to 250 °C at 5 °C·min<sup>-1</sup> and
 maintained at 250 °C for 2 min. The transfer line temperature was set to
 250 °C, and helium was used as the carrier gas at a flow rate of 1
 mL·min<sup>-1</sup>. The MS source was operated in electron
 impact (EI) mode at 70 eV, and the MS was scanned from 40 to 500
 m·z<sup>-1</sup>. The concentrations of five classes of
 secondary metabolites, namely alkaloids, amines, esters, organic acids,
 and phenols, were determined by summing the relative peak area (RPA) of
 each class of compounds.
description: # Data from: Invasive submerged plant has a stronger inhibitory effect on
 epiphytic algae than native plant This dataset includes: (1) speme-specie
 data of abundance in the outdoor mesocosm experiment; (2) spece-specie
 data of abundance in the laboratory cultivation experiment; (3) ctme-data
 of epiphytic algal communities traits in the outdoor mesocosm experiment;
 (4) ctce-data of epiphytic algal communities traits in the laboratory
 cultivation experiment; (5) envme-environmental parameters in the outdoor
 mesocosm experiment; (6) envce-environmental parameters in the laboratory
 cultivation experiment; (7) pt-data of plant traits; Information for
 column headers Table speme: ID-sample ID, column heads B1 to AV1 was algae
 species ID. Unit: Cell/mm2 Table spece: ID-sample ID, column heads B1 to
 Z1 was algae species ID. Unit: Cell/mm2 Table ctme: ID-species ID,
 time-measurement time (unit: day), group-group, chla- epiphytic algal
 chlorophyll a concentration (unit: ug/L), FvFm-maximum quantum efficiency
 of Photosystem II of epiphytic algae, S-species richness, N-abundance
 (unit: Cell/mm2) Table ctce: ID-species ID, time-measurement time (unit:
 day), group-group, chla- epiphytic algal chlorophyll a concentration
 (unit: ug/L), FvFm-maximum quantum efficiency of Photosystem II of
 epiphytic algae, S-species richness, N-abundance Table envme:ID-sample ID,
 T-water temperature (unit: °C), DO-dissolved oxygen (unit: mg/L), pH-pH
 value, Turb-Turbidity (unit: NTU), TP-total phosphorus (unit: mg/L),
 TN-total nitrogen (unit: mg/L), DIC-dissolved inorganic carbon (unit:
 mg/L), Chla-chlorophyll a concentration (unit: ug/L) Table envce:
 ID-sample ID, DO-dissolved oxygen(unit: mg/L), pH-pH value, Turb-Turbidity
 (unit: NTU), TP-total phosphorus (unit: mg/L), TN-total nitrogen (unit:
 mg/L), DIC-dissolved inorganic carbon (unit: mg/L); alkaloids, amines,
 esters, organic acids, and phenols-the relative peak area of each class of
 compounds (unit: %) Table pt:ID-species ID, time-measurement time (unit:
 day), group-group, DW-plant dry weights (unit: g), FvFm-plant maximum
 quantum efficiency of plantPhotosystem II, length-plant length (unit: cm);
 alkaloids, amines, esters, organic acids, and phenols-the relative peak
 area of each class of compounds; TSM-the relative peak area of total
 secondary metabolites(unit: %)