DOI: 10.5061/dryad.12jm63z6k
title: Data from: Water regime and nitrogen enrichment facilitate the encroachment of woody plants at various developmental stages in freshwater marshes

description: It is often presumed that the establishment of woody plants into
 grass-dominated freshwater marshes is influenced by environmental changes
 such as alterations in water regimes and nutrient availability. However,
 it has not been rigorously tested through empirical studies. We conducted
 a three-year common garden experiment in a freshwater marsh to investigate
 the separate and combined effects of water (flooded vs. drained) and
 nitrogen levels (ambient vs. added) on germination, seedling survival,
 growth of seven woody plant species, and their potential competitive
 interactions with the resident vegetation. Drainage in the first year
 significantly improved both seed germination and seedling survival of
 woody plants, and these survival benefits persisted over the following two
 years. The structural equation model revealed that drainage indirectly
 facilitated seedling survival by reducing light asymmetry. In contrast,
 continuous flooding over three years resulted in complete seedling
 mortality. However, after three years of drainage, the addition of
 nitrogen significantly increased the leaf count, maximum height, and stem
 diameter of the surviving woody plants. Our study demonstrates that water
 regime is the primary factor driving the establishment of woody plant
 seedlings in freshwater marshes. As seedlings mature, nutrient
 supplementation can accelerate their development, potentially accelerating
 their encroachment into freshwater marshes.
description: Our dataset have four files including
 "Seed_germination","Seedling_survival","Seedling_growth"and "Survival_SEM". 1. Explanation for the header in “Seed_germination”: ID: the plot number in each block, eg plot1_2 means the second plot in the first block; Block: the block in our experiment, total ten block, and each block has 28 plots. Species: species of woody plants, which as random effect in all models; Genus: genus of woody species; Family: family of woody species Sowing: the seed numbers that sowed in each plot; Nutrient: nutrient availability treatment include two levels of "High_N" vs. "Low_N", which was specified as fixed-effect-independent variable in all modes; Water: simulated herbivory treatmet including two levels of "flooded"vs. "drained", which was specified as fixed-effect-independent variable in all modes; Survival20_07: Seed germination numbers in each plot, which was specified as response variable. 2. Explanation for the header in “Seed_survival”: Year: Three different years the experiment conducted; ID: the plot number in each block in different year, eg. Y2020_plot1_10 means the tenth plot in the first block in year of 2020; Block: the block in our experiment, total ten block, and each block has 28 plots. Species: species of woody plants, which as random effect in all models; Genus: genus of woody species; Family: family of woody species Sowing: the seed numbers that sowed in each plot; Nutrient: nutrient availability treatment include two levels of "High_N" vs. "Low_N", which was specified as fixed-effect-independent variable in all modes; Water: simulated herbivory treatmet including two levels of "Wet"vs. "Drought", which was specified as fixed-effect-independent variable in all modes; Survival: Seedling survival numbers in each plot under different treatment, which was specified as response variable. 3. Explanation for the header in “Seedling_growth”: ID: the plot number in each block, eg. plot1_2 means the second plot in the first block; Block: the block in our experiment, total ten block, and each block has 28 plots. Species: species of woody plants, which as random effect in all models; Genus: genus of woody species; Family: family of woody species Sowing: the seed numbers that sowed in each plot; Nutrient: nutrient availability treatment include two levels of "High_N" vs. "Low_N", which was specified as fixed-effect-independent variable in all modes; Water: simulated herbivory treatmet including two levels of "Wet"vs. "Drought", which was specified as fixed-effect-independent variable in all modes; Leaf_Number21_08: The average leaf numbers of all woody plants in each plot under different treatments in year of 2021, which was specified as response variable. Height21_08 （cm）: The average height of all woody plants in each plot under different treatments in year of 2021, which was specified as response variable. The unit for this variable is cm. Leaf_Number22_08: The average leaf numbers of all woody plants in each plot under different treatments in year of 2022, which was specified as response variable. Height22_08 (cm): The average height of all woody plants in each plot under different treatments in year of 2022, which was specified as response variable. The unit for this variable is cm. Stem_diameter22_08 (cm): The average stem diameter of all woody plants in each plot under different treatments in year of 2022, which was specified as response variable. The unit for this variable is cm. 4. Explanation for the header in “Survival_SEM”: ID: the plot number in each block, eg plot1_2 means the second plot in the first block; Block: the block in our experiment, total ten block, and each block has 28 plots. Species: species of woody plants, which as random effect in all models; Genus: genus of woody species; Family: family of woody species Nutrient: nutrient availability treatment include two levels of "High_N" vs. "Low_N", which was specified as fixed-effect-independent variable in all modes; Water: simulated herbivory treatmet including two levels of "Wet"vs. "Drought", which was specified as fixed-effect-independent variable in all modes; Sowing: the seed numbers that sowed in each plot; Survival: Seedling survival numbers in each plot under different treatment. Light_asy: Light asymmetry in each plot. Native_biomass (g): Total aboveground biomass in each plot. The unit for this variable is g. NA in the cells are missing values.