Seasonal precipitation distribution determines ecosystem CO₂ and H₂O exchange by regulating spring soil water-salt dynamics in a brackish wetland

The intensification of the global hydrological cycle is anticipated to increase the variability of precipitation patterns. Brackish wetlands respond to changes in precipitation patterns by regulating the absorption and release of CO2 and H2O to maintain the stability of ecosystem functions. However, there is limited understanding of how the inter-seasonal precipitation distribution affects ecosystem CO2 and H2O exchange compared to annual precipitation totals. Here, we conducted four consecutive years of field experiments in a brackish wetland, manipulating the proportion of precipitation across different seasons while maintaining a constant annual precipitation total. We utilized five inter-seasonal precipitation distribution proportions (+73%, +56%, control (CK), -56%, and -73%) to examine the effects of seasonal precipitation distribution (SPD) on ecosystem CO2 and H2O exchange. Our findings revealed that the ecosystem CO2 and H2O fluxes showed a trend of decreasing with the decrease..., Abiotic factors measurements
From April 2022 to March 2023, a soil three-parameter sensor (HdyraProbe Lite Soil Moisture sensor, Stevens Water, USA) was used to measure surface (0-10 cm) soil volumetric moisture content (SM), soil electrical conductivity (EC), and soil temperature (ST). Data were logged once a day throughout the experimental period using a data logger (CR1000, Campbell Science, Inc., USA).
Biotic factors measurements
In May 2019, a 1 × 1 m quadrat was selected in each plot as a permanent vegetation survey area by diagonal crossing. Vegetation surveys were conducted on a clear morning of every quarter in 2022 to record indicators such as coverage. At the end of the 2022 growing season, aboveground biomass (AGB) was obtained by the cutting method, and belowground biomass (BGB) was obtained by root drilling on the 1 × 1 m quadrate. Subsequently, AGB and BGB were placed in an oven, first baked at 105 ℃ for 1 h, then converted to 70 ℃ for 48 h, and finally weighed to obtain ..., , # Seasonal precipitation distribution determines ecosystem CO₂ and H₂O exchange by regulating spring soil water-salt dynamics in a brackish wetland

[https://doi.org/10.5061/dryad.pc866t1z3](https://doi.org/10.5061/dryad.pc866t1z3)

## Description of the data and file structure

Data usage bootstrap:

See abiotic factors data at: Huang et al.\_ abiotic factors

See biotic factors data at: Huang et al.\_ biotic factors

See ecosystem CO₂ and H₂O exchange data at: Huang et al.\_ ecosystem CO₂ and H₂O exchange

See structural equation model fitting at: Huang et al.\_ SEM

See simulated precipitation at: Huang et al.\_ Precipitation

## DATA-SPECIFIC INFORMATION FOR: Huang et al.\_ abiotic factors

1. Number of variables: 3
2. Number of sheets: 3
3. Number of cases/rows: 6 columns 366 rows/sheet

#### Variable List:

* EC: soil electrical conductivity ds/m
* \"Soil electrical conductivity\" refers to the ability of ions dissolved in soil solution to conduct current. It is a measure of the s...