First, let’s look at photosynthesis. Water + Carbon Dioxide = Plant Material + Oxygen. You probably knew that already. Plants need water to make oxygen. But there’s more—a lot more. It turns out that only ten percent of the water that’s sucked up by a plant’s roots is used for photosynthesis. The rest is used for transpiration. Through transpiration, water evaporates from the undersides of leaves and is drawn up from the roots. This process cools the leaves, exchanges oxygen and carbon dioxide, and moves nutrients up the tree.
No water in the tree = no cooling of the leaves= lower temperature on body, tip and leaves
All tree leaves have 'thermostat' that maintains temperature but it is meaningless if there is no water to regulate it. The conversion of light into chemical energy - photosynthesis - most likely occurs when leaf temperatures are about 21°C, and the outside temperature plays little, if any, role. This means that in colder climates leaf temperatures are elevated and in warmer climates tree leaves cool to keep the temperature just right.
It is known that the ROD fungus attacks the Ohi’a tree by chocking the water transport resulting in the tree to become dry until it dies. Meaning lower water on the Ohi'a tree means no regulation of temperature.
By doing statistics on the temperature of the average ohia tree have during all season, we can get an early warning system when we measure infected ohia tree showing different temperature reading.
Comments are very welcomed!!