How Do Plants and Climatic Conditions Control Soil Properties in Hypersaline Tidal Flats?

Abstract

Hypersaline tidal flats (HTF) are ecotones associated with mangrove ecosystems in arid and semiarid coasts. They are predominantly vegetated by halophytes which are related to environmental stabilization and fauna protection. Some plants thrive in HTF by modifying soil biogeochemical conditions at their rhizospheres, expanding across barren soils. Thus, we aimed to study rhizospheric and the adjacent bulk soils of the three most abundant plant species in HTF under a seasonal semiarid climate of northeastern Brazil. We analyzed both rhizospheric and bulk soils of vegetation patches in wet and dry seasons. We found that HTF soils are a heterogeneous system highly influenced by water availability and plant activity. The soils were mostly sandy textured, containing low C and N contents, and hypersaline conditions. Comparing bulk and rhizospheric soils, we concluded that plants changed their own rhizosphere by creating nutrient pools to improve survival under saline conditions. Seasonal changes also affected soil biogeochemical processes in HTF, mainly the bulk soils by changing water availability. Understanding rhizospheric changes by halophytes, their expansion over barren soils, and the amelioration of soil physicochemical conditions, are fundamental to provide support for preservation and management of coastal ecosystems, including HTF.

Bridging soil biogeochemistry and microbial communities (archaea and bacteria) in tropical seagrass meadows

“…Diverse studies have shown that soils of coastal wetlands (e.g., mangroves, salt marshes, and hypersaline tidal flats) can be very dynamic and spatially variable, resulting from an interaction between biotic (e.g., plant species and bioturbation; Araujo Juńior et al, 2012;Cabral et al, 2020), and abiotic factors (i.e., physiographic position, flooding frequency, geological bedrocks, and climate; Seybold et al, 2002;Du Laing et al, 2009;Albuquerque et al, 2014;Ferronato et al, 2016;Ferreira et al, 2022).…”

Morphophysiological Characterisation of Guayule (Parthenium argentatum A. Gray) in Response to Increasing NaCl Concentrations: Phytomanagement and Phytodesalinisation in Arid and Semiarid Areas

“…Soils are classified as saline when the ECe is 4 dS m −1 or more [7], equivalent to approximately 40 mM or 2.3 g L −1 NaCl. In this scenario, the continuous increase in salinisation (and sodification) transforms saline areas into hypersaline ones, which are extreme environments where the salinity is very high (similar or higher than that of seawater, 35-40 g L −1 NaCl or 600-680 mM), where plant growth is strongly limited and may be suitable for halophytes only [8][9][10].…”