from English Grammar Today. Efficient and effective are adjectives. We use efficient to describe something or someone that works in a quick and organised way: The new online banking system offers a convenient and efficient way to check your account. [extract from a reference for someone applying for a job]
Main Disease. Oak wilt is caused by the fungus Ceratocystis fagacearum which develops in the outer sapwood of the tree. The infected tree reacts by developing tyloses and gums which subsequently restrict the flow of water and nutrients in affected vascular tissues with the result that the tree wilts and subsequently dies (French & Stienstra, 1980). Host Range.
Your live oak directs its vegetative growth energy into forming these new leaves -- the older leaves lack the moisture and nutrients necessary for sustained growth and die back. The temperature change between winter and spring is the signal to start this new growth to take advantage of the lengthening days.