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We have two infant Norfolk pines planted in the ground on property in west central Florida. There has been some concern about these trees 'sucking up' all the water in the water table. We are on a peninsula jutting out into St. Joseph Sound near Tarpon Springs. Is this truly a cause for concern?

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I am not a hydrologist or a geologist or anything like that, but we can all read about a phenomenon called "watering-up"; there is a review article here which indicates that when trees are removed the water table can rise measurably, depending on the soil type. Deciduous trees can "divert" falling rain back into the atmosphere by 15% and evergreens do so to 30%. I suppose this means that by wetting the tree bark and leaves the rain never actually makes it to the ground to percolate down into the water table - it rather clings to the surface it lands on and then slowly evaporates. And the rain that does reach the ground is trapped by capillary action and made available to the tree roots, from whence, again, it travels back to the canopy to be evaporated and transpired. Where there are no trees, more rain can reach the surface and more of that can reach the water table. So the presence of trees might be less "sucking up" than preventing percolation down.

But then you must ask whether there would be as much rain? With no trees to put water back into the air the humidity will fall making it less likely to rain. Also there is the issue of fast runoff; when rain hits dry ground not penetrated by tree roots it is likely to head to the nearest city drain to be fast transported to the ocean.

Norfolk Island Pine can grow to 100 feet and looks pretty strange if it is not allowed to grow naturally - I hope you have a large yard for them to grow in and they have enough space.

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