July 4, 2005. Paola, Kansas The same tree but a half a day later when the sun was stronger. Noted. The change in the condition of the leaves as the tree dehydrates and dies. It is hard to believe sometimes that trees are that delicate, but, they are simply big water pumps that sustain their hydration and nutrition by simple osmotic pressure. As the water vapor from the leaves evaporates more is pulled from the soil through the roots. When that osmotic pump stops the tree quickly dehyrates and dies. This was far from a dead or diseased tree as exhibited by the change in the leaves alone.