Soil phase - A subdivision of a soil series having features (e.g. slope, sur- 

 face texture, and stoniness) that affect the use and management of the soil, 

 but which do not vary sufficiently to differentiate it as a separate series. 

 These are usually the basic mapping units on detailed soil maps produced by 

 the Soil Conservation Service. 



Soil pore - An area within soil occupied by either air or water, resulting 

 from the arrangement of individual soil particles or peds. 



Soil profile - A vertical section of a soil through all its horizons and 

 extending into the parent material. 



Soil series - A group of soils having horizons similar in differentiating char- 

 acteristics and arrangement in the soil profile, except for texture of the 

 surface horizon. 



Soil structure - The combination or arrangement of primary soil particles into 

 secondary particles, units, or peds. 



Soil surface - The upper limits of the soil profile. For mineral soils, this 

 is the upper limit of the highest (Al) mineral horizon. For organic soils, It 

 is the upper limit of undecomposed , dead organic matter. 



Soil texture - The relative proportions of the various sizes of particles in a 

 soil . 



Somewhat poorly drained - Soils that are wet near enough to the surface or 

 long enough that planting or harvesting operations or crop growth is markedly 

 restricted unless artificial drainage is provided. Somewhat poorly drained 

 soils commonly have a layer with low hydraulic conductivity, wet conditions 

 high in the profile, additions of water through seepage, or a combination of 

 these conditions. 



Stilted roots - Aerial roots arising from stems (e.g., trunk and branches), 

 presumably providing plant support (e.g., Rhizophova mangle). 



Stoollng - A form of asexual reproduction in which new shoots are produced at 

 the base of senescing stems, often resulting in a multitrunk growth habit. 



Stratigraphy - Features of geology dealing with the origin, composition, 

 distribution, and succession of geologic strata (layers). 



Substrate - The base or substance on which an attached species is growing. 



Surface water - Water present above the substrate or soil surface. 



Tidal - A situation in which the water level periodically fluctuates due to 

 the action of lunar and solar forces upon the rotating earth. 



Topography - The configuration of a surface, including its relief and the 

 position of its natural and man-made features. 



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