Most mineral soils have a fairly high buffer capacity against pH increases from acidic organic amendments. I'd be far more concerned with the N drawdown/immobilization associated with incorporation of wood components - especially those that have a high % of sapwood - like whole chipped trees or sawdust of any kind.

Pine bark is generally less acidic than sphagnum peat, which usually ranges from 3.0-4.0 with pine bark at 3.5-5.0. with some as high as 6.0.

The idea that wood chips, pine needles and oak leaves create acid as they decompose has to have been invented by someone who is still confused by what came first, the pH or the trees. In nature, what grows is based on natural selection over time. If we find pine forests where the soil tends to be more acid than not, does it automatically mean that the acidity was somehow formed by the trees? Of course not; when tree seeds germinate in soils which are favorable to their growth are going to thrive. So, as a general rule, plants of all description are going to do best in areas where they grow and reproduce the best, i.e., the plants selected the soil, not the other way around. It is just too easy to assume that because oak and pine trees prefer acid soils, that their decomposing leaves created the acidity in the soil. Those soils were acid before the trees got there, or the trees would not have thrived and created forests. You will find that major and long-lasting changes in garden soil pH can only be obtained with corresponding changes in the mineral content of that soil. Mulches composed of garden wastes, garden compost, leaf mold, composted wood chips, or almost any composted biodegradable materials just don't create any significant long term change in the pH of your garden soil - especially when used as a 'minor' ingredient as you suggested it would be.

I wouldn't use sawdust or chipped wood in my container soils, however.

Al

Thanks, Al. You told me all I needed to know and confirmed much of what I suspected.

I've done pretty well with the wood chips and sawdust in the containers. It is what I refer to as "almost compost." Aged a couple of seasons with chicken droppings.

Thanks, again. Kay.