© 2019 Scholars Academic Journal of Biosciences | Published by SAS Publishers, India 205 Scholars Academic Journal of Biosciences Abbreviated Key Title: Sch Acad J Biosci ISSN 2347-9515 (Print) | ISSN 2321-6883 (Online) Journal homepage: http://saspublisher.com/sajb/ Physicochemical Characterisation of Hydromorphic Soils under Fleroya stipulosa (Rubiaceae), a Vulnerable and Highly Medicinal Plant in Cameroon Roland Nnomo Douanla 12* , Bernard Palmer Yerima 2 , Victor François Nguetsop 1 , Adalbert Adibime Onana 2 and Bertine Tiokeng 1 1 Laboratory of applied Botany (LAAB), Plant Biology Departement, Faculty of Sciences, University of Dschang Po Box: 67, Dschang, Cameroun 2 Laboratory of Soil Analysis and Environmental Chemistry (LASAEC), Soil Sciences Department, Faculty of Agronomy and Agricultural Sciences, University of Dschang Po Box: 67, Dschang, Cameroon *Corresponding author: Roland Nnomo Douanla | Received: 27.03.2019 | Accepted: 06.04.2019 | Published: 30.04.2019 DOI: 10.21276/sajb.2019.7.4.6 Abstract Original Research Article This study aimed at characterising hydromorphic soils under F. stipulosa in Cameroon. A representative soil profile of its realized niche was excavated, and soil samples collected for selected physicochemical analysis following standard procedures. The profile was clay loamed at the surface and clayey at the subsurface due to a high content in mineralogical clays. Bulk density (BD) was low in surface and high in-depth, while total porosity had an opposite trend. These soils were generally acidic to slightly acidic, with low pH-values subjecting the soil to exchangeable acidity (EA). Organic matter (OM) content was quite satisfactory, though the alternating wet/dry conditions hindered mineralization. For these reasons, organic carbon (OC) and total nitrogen (TN) stocks were more or less important in some horizons depending on their susceptibility to waterlogging. Phosphorus content was high to moderate in the surface and low at the subsurface. Cationic exchange capacity (CEC 7 ) rated high, accounting for good potentiality of these soils in terms of fertility. The latter was principally due to smectitic clay minerals as evidenced by the high values of CEC -Clay along the profile. However, mineral fertility was poor as the complex had few nutrients thanks to low pH values that qualified the profile for having an effective CEC (ECEC). The latter were low however and decreased with depth, together with related characteristics such as total exchangeable bases (TEB) and base saturation at ECEC (BS -CECE ), thus requiring adequate measures in order to improve the soil’s effective holding capacity for nutrients and its sustainability. Keywords: Wetlands, physicochemical characteristics, hydromorphic soils, Rubiaceae, Cameroon. Copyright @ 2019: This is an open-access article distributed under the terms of the Creative Commons Attribution license which permits unrestricted use, distribution, and reproduction in any medium for non-commercial use (NonCommercial, or CC-BY-NC) provided the original author and source are credited INTRODUCTION The main objective of research in soil science is the understanding of the nature, properties, dynamics and functions of the soil as part of landscapes and ecosystems [1]. Hydromorphic soils are those that are saturated at or near the soil surface with water, and virtually lack free oxygen for significant periods of a given year. They are also referred to as soils affected by redox processes with a particular dynamism of organic matter. Many classification systems, group these soils either under rédoxisols, réductisols, histosols, Planosols or Gleysols, depending on the intensity of hydromorphism. However, the American system of classification (Soil Taxonomy) does not consider hydromorphic soils as a distinct reference soil group, arguing that hydromorphism can affect any type of soil [2]. The occurrence of such soils is usually conditioned by both climate and physiography and the total area which has to do with places where the land’s drainage capacity falls short of evacuating the water surplus which may originate from rainfall, surface runoff and ground water flow; thus, they are most prevalent in humid climate and low-lying land [3, 4]. In Cameroon, these soils occur in almost all the agro ecological zones, with the greater part of it being concentrated along the coastal part of the country, flood plains, marshes and alluvial plains [5]. These soils commonly restricted to wetlands serve as refuge to many endemic species of plant with a large percentage being typically infeodated [6]. However, because of demographic pressure, lack of fertile land added to the drop in fertility level of previously cultivated areas, there is an increasing demand for land to intensify agriculture, one of the basic mean of incomes and livelihood of the population in this region. This often results in the conversion of previously abandoned lands such as swamps into farm land after a huge destruction of the natural vegetation may have occurred. Consequently, there is a loss of biodiversity, with hygrophilic plants mostly affected, due to their immobility, their susceptibility to brutal environmental changes and finally their restricted ecological amplitude. Biodiversity