Table 1.
Plant species measured in the mesocosms.
Fig 1.
During the 16 month-long growth period, all mesocosms were flooded to 15 cm water depth while plants spread from initial plantings throughout the mesocosms. During the 24-day pre-treatment period, all mesocosms were flooded to 30 cm water depth to initiate the start of the treatments. In late May 2020, the first drawdown period began and lasted for 160-days, then 80 days later the 80-day duration drawdown period began, followed in turn by the 40-, 16-, 8-, 4- and 2-day drawdown periods. Each drawdown duration had multiple water level depths. For the 160- and 80-day drawdowns, arrows indicate the starting water depths and then the general trajectories of declining water depth thereafter due to evapotranspiration. For clarity, arrows are not shown for the shorter drawdown periods. All treatment durations ended on the same day in October 2020 when the recovery period began. During the 7-month recovery period, all mesocosms were maintained at 15 cm water depth until the harvest in May 2021.
Fig 2.
Soil water content (percent of the mass of a wet soil sample consisting of water) overtime, averaged across water depths for each drought period.
Fig 3.
Plant abundance for Typha (a-c), Schoenoplectus (d-f), E. cellulosa (g-i) and E. montevidensis (j-l) as a function of drought length and water depth. The first column of panels shows plant abundance at the end of the treatment period, the second column shows the end of the recovery period and the last column shows the biomass (g/m2) at the final harvest. Statistical results are shown in Table 2.
Fig 4.
Plant abundance for Juncus (a-c), Bacopa (d-f), Hydrocotyle (g-i) and Ceratophyllum (j-l) as a function of drought length and water depth. The first column of panels shows plant abundance at the end of the treatment period, the second column shows the end of the recovery period and the last column shows the biomass (g/m2) at the final harvest. Statistical results are shown in Table 2.
Table 2.
Plant abundance.
Fig 5.
Aboveground total live biomass (a), aboveground dead biomass (b) and belowground total live biomass (c) (g/m2) as a function of drought length and water depth.
Fig 6.
NMDS ordination of plant community composition as a function of drought length. Separate analyses were conducted for the end of treatment, end of recovery and final harvest. Abundance metrics used in the NMDS for panel a and b followed the abundance metrics used for each species (Table 1) and the abundance metric used in panel c was plant biomass (g/m2). 2D stress values were less the 0.20 indicating results do not have to be interpreted with caution.
Fig 7.
Animal abundance for mosquito larvae (a-c), snails (d-f) and tadpoles (stage 1) (g-i) as a function of drought length and water depth. Dates chosen for the treatment period and recovery period vary among species to reflect the date when each species was most abundant. The first column of panels shows animal abundance during the treatment period, the second column shows abundance during the recovery period and the third column shows abundance at the end of the recovery period. Statistical results are shown in Table 2.
Table 3.
Animal abundance.