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3. pH of PA streams

I recently learned some interesting PA history from a guy from the DCNR Forestry Service. He said that the state was almost completely clear-cut (something like 85%) a hundred years ago. Since then, the state's forests have been allowed to flourish to the point that today about 65% of the state is again forested. The interesting part is that the state used to be almost completely softwooded, coniferous forest. After the clear-cut, though, the deciduous hardwoods outcompeted the coniferous species and took over, to the point that PA is now home to one of the biggest hardwood industries in the world.

That is all nice history, but it left me wondering about our trout streams. Does anyone know what the pH of our streams was before the clear-cut? I presume that the pines that predominated prior to the clear-cut contributed a great deal of acidity to the soil, whereas the hardwoods we have today likely contribute much less acidity. I know this is just one variable among many (acid rain, of course, and the buffering capacity of the streams themselves being those most mentioned), but I was hoping someone more knowledgeable than I could comment on whether local flora can be a major contributor to pH of streams. I wonder, is it possible that what we think of as our streams' "natural" pH is actually substantially higher than what it really was before people began to seriously impact it?

-Shawn

this thread is the most amazing one on this board--NOT ONE of the very well educated, well spoken, and well-meaning folks who frequent it have managed to post anything in reply. even my valiant attempt wound up in the trash. Shawn, i have absolutely no idea how one would go about finding out the pH of streams 100 years ago, outside of measuring a large number of streams under different tree covers, and then making a guess. you'd have to factor in the different geological situations of the streams, and that just might derail the whole thing.

YO! science dudes! any good ideas out there?

maybe acid rain has kept the pH the same after all...

i'll second your sentiments casey, i'm hoping the global warming thread hasn't chased away all the scientists.
jeff

If that's true, then I deserve at least some of the blame. I do miss Gene - if he were still here, I'm sure I would have at least gotten an amusing tongue-lashing for something I said. Good times. I, too, am quite surprised to have gotten no responses. I really hope it's just because people are busy and not because they've been chased away.

-Shawn

Know one probably can figure out the exact number was, but from those facts provided, it must have been way more acidic right. That does make sense considering that it is known that all the trout streams back then were solely brook trout fisheries, even the limestone streams.

Know one probably can figure out the exact number was, but from those facts provided, it must have been way more acidic right.

Hi Guys
I sure am not very knowledgeably about this ,but I think the opposite might be true. Wasn't the bug numbers and different kinds of aquatic insects more prolific before they cut the trees.

John

I might be mixed up, but arent pine needles acidic?

Folks - while the aquatic chemistry classes were years ago this seems to follow the little I remember.

http://www.ecy.wa.gov/programs/wq/plants/management/joysmanual/streamph.html