## 5 Conclusions  
Our study revealed that biogeochemical soil properties in HTF of the Brazilian semiarid coast were affected by seasonality and the plant-rhizosphere-soil conditions. Consequently, the HTF can be characterized as a heterogeneous system that is highly influenced by water availability and by inhabiting plants capable of surviving under the suppressing hypersaline conditions.  
Comparing bulk and rhizosphere soils, one concludes that HTF plants were able to modify their rhizosphere-soil interface, increasing the availability of nutrients, which brings survival advantage for them and other plants species. Each of the studied plants was developed under different soil conditions, which is probably related to their physiological requirements and metabolism. For example, Bm and Bp where related to NH\({}_{4}\)\({}^{+}\), Bm to soil C and N contents, while Sv was highly correlated to soluble cations (such as K\({}^{+}\) and salinity).  
Seasonality directly impacted soil dynamics in HTF, such as the contents of exchangeable and soluble cations, EC, pH, and Eh values, mainly because of freshwater inputs. Despite the fact that rhizospheric soils were more affected by these seasonal changes, the plants adapted to maintain their rhizospheric environment were less variable to seasonal changes. Our results suggest that the combined effects of seasonal changes and plant action rule most of the biogeochemical processes in HTF, and that plants had the capacity to change the soil conditions to improve their development. Furthermore, our study provided essential information to improve the success of environmental restoration and preservation in salt affected and coastal soils.  
The following are available online at [[http://www.mdpi.com/2076-3417/10/21/7624/s1](http://www.mdpi.com/2076-3417/10/21/7624/s1)]([http://www.mdpi.com/2076-3417/10/21/7624/s1](http://www.mdpi.com/2076-3417/10/21/7624/s1)), Table S1. Particle size distribution (sand, silt, and clay) in g kg\({}^{-1}\) for both rhizosphere (Rz) and bulk soils for the three plant species (Bm, Bp, and Sv). There is no significant statistical difference (at 5% level) between Rhizospheric and Bulk soils for each species for sand, silt, and clay.  
Conceptualization, T.O.F, X.L.O., G.N.N., R.B.Z., and R.L.C.; methodology, T.O.F, X.L.O., S.R.R., R.B.Z., and R.L.C.; software, G.N.N., D.B., and R.L.C.; validation, T.O.F., D.B., S.R.R., X.L.O. and R.L.C.; formal analysis, R.L.C., G.N.N., D.B.; writing--original draft preparation, R.L.C., T.O.F., G.N.N., S.R.R., R.B.Z., X.L.O.; writing--review and editing, D.B. and G.N.N.; funding acquisition, T.O.F., X.L.O. All authors have read and agreed to the published version of the manuscript.  
The first author would like to thank CAPES for the financial support to R.L.C., T.O.F, and X.L.O. We thank the members of Nucleo de Pesquisia em Pedologia (Nuppe/UFC) for field and laboratory support and [PERSON] for laboratory assistance. The authors are grateful for the financial support provided by National Council for Scientific and Technology Development (CNPq, process 305996/2018-5; 409593/2018-4); Conselleria de Innovacion e Industria-Xunta de Galicia (PGIDIT08 MDS03600 PR); Cross-Research in Environmental Technologies of the Santiago de Compostela University (CRETUS) strategic group (AGRUP2015/02), Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro (GNN, JCNE Grant FAPERJE-26/202.757/2019), and Sao Paulo Research Foundation (FAPESP, DB: Grant # 2019/02855-0).  
The authors declare no conflict of interest.