DOI: 10.5061/dryad.fn2z34tx7
title: Data from: The hydrochorous dispersal of plant propagules in a giant river reservoir: implications for restoration of riparian vegetation

description: The riparian vegetation of many rivers around the world is impacted by
 flow regulation for hydropower. Water levels behind dams are being raised
 to generate electric energy, forming river reservoirs. River regulation
 has a large impact on the riparian vegetation which influences both the
 adjacent aquatic and terrestrial ecosystems. Therefore, restoration of
 degraded riparian vegetation in river reservoirs has been of increasing
 research interest. Propagules dispersed from connected tributaries via
 water (hydrochory) are considered a vital source for the recovery of
 riparian vegetation in regulated rivers. However, the hydrochorous
 dispersal of plant propagules in river reservoirs is unclear. We explored
 the dispersal distance and deposition patterns of hydrochorous propagule
 mimics in three tributaries that are regulated by the Three Gorges
 Reservoir (TGR) in China. In eight out of nine release experiments, 95% of
 propagule mimics were found within 3 km downstream from the release
 points. Cumulative wind speed was the most important factor affecting the
 dispersal distance of propagule mimics in the TGR. However, the dispersal
 distance of propagule mimics was not significantly affected by water-level
 variation and channel sinuosity. Variations in water level strongly
 affected the deposition pattern of propagule mimics, with only 6.6% of the
 propagule mimics stranding on the riparian zones under raised water level
 and 83.8% stranding under declined water levels. The majority of stranded
 propagule mimics were deposited at gentle slopes (0‒20°). Synthesis and
 applications. Our results suggest that the majority of propagules that
 enter river reservoirs via water would be retained within the first few
 kilometers. Wind and water level variation are the main factors
 determining the dispersal distance and deposition pattern of propagules.
 Our findings have applications for riparian vegetation restoration in
 river reservoirs. The vegetation in steep riparian zones distant from
 free-flowing tributaries should be the priority for restoration actions
 because these areas receive limited hydrochorous propagules. The plant
 biodiversity and hydrological connectivity of connected tributaries, which
 is an important propagule sources for riparian vegetation along river
 reservoirs, should be protected. The seasonal dominant wind pattern should
 be considered when evaluating the importance of tributaries as the source
 of hydrochorous propagules for river reservoirs.
description: <strong>Effects of
 environmental variables</strong>
 The effects of environmental
 variables on the downstream dispersal distance of propagule mimics.
 Abbreviations: D90 (the distances when 90% of retrieved propagule mimics
 were retained), WaterLevel (water level variation), Sinuosity (channel
 sinuosity), NetWind_Down (cumulative net wind speed towards downstream
 direction), Width (channel width), FlowVelocity (flow
 velocity). <strong>Filename</strong><strong>:</strong> Table
 2.CSV <strong>Dispersal distance of propagule
 mimics</strong> The dispersal distance of propagule mimics in
 three regulated tributaries. The positive and negative values in the
 column ‘Dispersal distance (km)’ indicate the downstream and upstream
 distance from the release points, respectively.
 <strong>Filename</strong><strong>:</strong> Figure
 3.xlsx <strong>Water level
 variation</strong> The water level variation of the Three Gorges
 Reservoir (TGR) during the release period of propagule mimics. The
 positive and negative values in the column ‘Relative water level (m)’
 indicate the water level of the TGR raised and declined, respectively.
 <strong>Filename</strong><strong>:</strong> Figure
 4_Left.xlsx <strong>Retrieved propagule mimics stranded on
 shorelines</strong> The percentage of retrieved propagule mimics
 stranded on shorelines of three regulated rivers under raising and
 declining water levels.
 <strong>Filename</strong><strong>:</strong> Figure
 4_Right.xlsx <strong>Retained patterns of the retrieved propagule
 mimics</strong> Percentage of the retrieved propagule mimics
 staying in the water and stranded on shorelines.
 <strong>Filename</strong><strong>:</strong> Figure
 5_Left.xlsx <strong>Propagule mimics stranded on different slope
 gradients</strong> Percentage of propagule mimics stranded on
 riparian zones with different slope gradients. Seven instead of nine
 release events are shown because the other two release events had no
 propagule mimics stranding on shorelines.
 <strong>Filename</strong><strong>:</strong> Figure
 5_Right.xlsx The floating ability of propagule mimics with
 different painting patterns
 <strong>Filename</strong><strong>:</strong>
 Figure_S1.xlsx <strong>Projected wind
 speed</strong> Projected wind speed towards downstream
 (positive values) and upstream directions (negative
 values). <strong>Filename</strong><strong>:</strong>
 Figure_S3.xlsx