DOI: 10.5061/dryad.s1rn8pk45
title: Data from: Zonation of mangrove flora and fauna in a subtropical estuarine wetland based on surface elevation

description: In the context of sea-level rise (SLR), an understanding of the spatial
 distributions of mangrove flora and fauna is required for effective
 ecosystem management and conservation. These distributions are greatly
 affected by tidal inundation, and surface elevation is a reliable
 quantitative indicator of the effects of tidal inundation. Most recent
 studies have focused exclusively on the quantitative relationships between
 mangrove-plant zonation and surface elevation, neglecting mangrove fauna.
 Here, we measured surface elevation along six transects through the
 mangrove forests of a subtropical estuarine wetland in Zhenzhu Bay
 (Guangxi, China), using a real-time kinematic global positioning system.
 We identified the mangrove plants along each transect and investigated the
 spatial distributions of arboreal, epifaunal, and infaunal molluscs, as
 well as infaunal crabs, using traditional quadrats. Our results indicated
 that 97.3% of all mangrove forests in the bay were distributed within the
 400–750 m intertidal zone, between the local mean sea level and mean high
 water (119 cm above mean sea level). Mangrove plants exhibited obvious
 zonation patterns, and different species tended to inhabit different
 niches along the elevation gradient: Aegiceras corniculatum dominated in
 seaward locations while Lumnitzera racemosa dominated in landward areas.
 Mangrove molluscs also showed distinct patterns of spatial zonation
 correlated with surface elevation, independent of life-form and season;
 the spatial distributions of some molluscs were influenced by the relative
 abundances of certain mangrove plants. In contrast, the spatial
 distributions of crabs in the bay were not correlated with surface
 elevation. To the best of our knowledge, this is the first study to
 explicitly quantify the influences of surface elevation on the spatial
 distributions of mangrove fauna in the intertidal zone. This
 characterization of the vertical ranges of various ﬂora and fauna in
 mangrove forests provides a basic framework for future studies aimed at
 predicting changes in the structure and functions of mangrove forests in
 response to SLR.
description:         Six transects (each approximately 400–750 m long) were
 drawn across the five main mangrove forests, from the seaward forest edge
 to the shore. In order to fully investigate the mangrove forests of the
 bay, we ensured that the transects covered a broad geographical area: from
 the bay mouth to the top of the bay. All transects were at least 1 km
 apart. Elevation along each transect was measured in 5–10 m surface
 intervals that were relatively flat, using a Global Navigation Satellite
 System-Real Time Kinematic GPS unit (G970 GNSS RTK, UniStrong Inc.,
 Beijing, China); this unit has a vertical precision of 15 mm. The
 elevation of each surface interval was converted to the Chinese Height
 Datum using point correction, performed based on control points located 3
 km from the study area. The elevation of the local MSL relative to the
 Chinese Height Datum was 0.34 m (EBCBS, 1993). Therefore, surface
 elevation relative to the local MSL was determined by subtracting 0.34 m
 from the measured elevation. Next, we established sampling sites at 25 cm
 vertical increments along each transect from the seaward edge to the
 landward edge. Because the elevation range varied among transects, the
 number of sampling sites along each transect also differed. In addition,
 due to topographic fluctuations, some transects included more than one
 site at the same height.       At each sampling site,
 because there was only one layer in the vegetation canopy, mangrove plant
 composition and abundance were recorded by number of individual (for
 specimens &gt;0.5 m tall) in three randomly selected quadrats (5 × 5
 m; 10 m apart). We sampled the arboreal, epifaunal, and infaunal molluscan
 communities, as well as the infaunal crab communities, at each site in
 July 2017 (rainy season) and in January 2018 (dry season). To collect
 arboreal molluscs, all specimens attached to trunks, leaves, prop roots,
 and other tree parts were collected by hand in each mangrove quadrat. To
 collect epifaunal molluscs, we randomly designated 5 epifaunal-mollusc
 quadrats (1 m × 1 m; 5 m apart) per sampling site, and all molluscs on the
 sediment surfaces of these quadrats were collected. To collect infaunal
 molluscs and crabs, we randomly designated a 25 × 25 cm area in each
 epifaunal-mollusc quadrat; we then sieved the uppermost 30 cm of the
 sediment in these areas through a 1-mm mesh (Liu, Wang, Wang, Fu,
 & Lu, 2016). All specimens were identified to species following
 Okutani (Okutani, 2000) and Wang et al. (Wang, Zhang, Ma, Cai, &
 Zhang, 2016), and then counted and weighted. 
description: Abbreviations of species: Ac, <i>Aegiceras
 corniculatum</i>; Am, <i>Avicennia marina</i>; Ko,
 <i>Kandelia obovata</i>; Bg, <i>Bruguiera
 gymnorhiza</i>; Eag, <i>Excoecaria agallocha</i>; Lr,
 <i>Lumnitzera racemosa</i>; Ls, <i>Littoraria
 scabra</i>; Eae, <i>Enigmonia aenigmatica</i>; Lm,
 <i>Littoraria melanostoma</i>; Lp, <i>Littoraria
 pallescens</i>; Lar, <i>Littoraria ardouiniana</i>; Ts,
 <i>Terebralia sulcata</i>; Co, <i>Cerithidea
 ornata</i>; Cn, <i>Cassidula nucleus</i>; Cc,
 <i>Cerithidea cingulata</i>; Bm, <i>Batillaria
 multiformis</i>; Ab, <i>Assiminea brevicula</i>; Md,
 <i>Mainwaringia dantaae</i>; Alay, <i>Allochroa
 layardi</i>; Cm, <i>Cerithidea microptera</i>; Alat,
 <i>Assiminea latericea</i>; Cl, <i>Cerithidea
 largillierti</i>; Ss, <i>Salinator sanchezi</i>; Isp,
 <i>Iravadia</i> sp.; Iq, <i>Iravadia quadrasi</i>;
 Isa, <i>Iracadia sakaguchii</i>; Nv, <i>Neritina
 violacea</i>; Sj, <i>Stenothyra japonica</i>; Cdj,
 <i>Cerithidea djadjariensis</i>; Pcy, <i>Pinguitellina
 cycladifomis</i>; Lan, <i>Laternula anatina</i>; Isc,
 <i>Indoaustriella scarlatoi</i>; Gch, <i>Glauconome
 chinensis</i>; Ip, <i>Indoaustriella plicifera</i>; Gco,
 <i>Geloina coaxans</i>; Me, <i>Macrophthalmus
 erato</i>; Pcr, <i>Paracleistostoma cristatum</i>; Cdi,
 <i>Cleistostoma dilatatum</i>; Sp, <i>Sesarma
 plicata</i>