WATER

The universal solvent and how it works

The structure of water allows some unique characteristics:

• POLARITY – 2 H atoms and 1 O atom covalently bond, giving an angled molecule of 105 degrees; the O atom more electronegative than the H atoms

• THERMAL PROPERTIES – high specific heat means it takes a lot of heat to raise the temperature; keeps water temperature from fluctuating; high heat of vaporization allows plants to cool using evaporation from the heat of the sun

WATER STRUCTURE PROPERTIES:

• TENSILE STRENGTH – ability of water to stay together, resists pulling forces for capillary action (plant pull water up into itself)

• DIFUSSION – the gradual mixing of molecules to dissipate a concentration difference

• EQUILIBRIUM – diffusion of molecules to homeostasis, or even distribution

• OSMOSIS – cell semipermeable membrane allows for SELECTIVE movement of water and uncharged substances into/out of cells, and restricts larger solutes and charged substances; concentrations as well as pressure drive this process

WATER’S UNIQUE PROPERTIES

COHESION – the mutual attraction of like molecules (attracts to itself)

WATER’S UNIQUE PROPERTIES

TENSILE STRENGTH – ability of water to stay together, resists pulling forces, for CAPILLARY action (how plants pull up water into itself). Water pulls itself along from root up plant and out leaves.

ADHESION – attraction of water to solids substances (attracts to others)

WICKING – tensile strength allows water to move along

DIFFUSION OF WATER

EQUILIBRIUM

OSMOSIS

WATER AND PLANTS

As rain falls, water picks up ions of nutrients, either cations (+) and/or anions (-) Roots move the ionized water by way of osmosis up the xylem, dispersing water and nutrients as neededAir is important as it sets up the gradient (from low to high water surrounding soil molecules)Water is absorbed, surrounding water is wicked to the plantEvaporation leads to loss of water, needs replenishing

PLANTS UTILIZING WATER AND NUTRIENTS

PLANT WATERWAY - XYLUM AND PHLOEM

WATER AND PLANTS

• Sandy soil lose water through gravity and evaporation at a fast rate, and creates a lot of air space

• Clay have little to no air spaces, tiny molecules surrounded by water, dries out slowly – if at all! When dry it is hard, compacted, and cannot support plants’ needs. Without the air spaces the roots drowned, as no gradient is set up. Plants rot.

• Humus though it can hold water, also makes soil porous, those air spaces needed for the gradient, and “breaks up” clay.

• Humus also is rich in those macronutrients and micronutrients that need replenishing BY WATER as they are used up, as well as food sources for macroinvertebrates