Soil & Water

Soil Suitability for Various High Quality Hardwoods

The history of silviculture is full of disasters.  Many of those disasters have to do with trying to grow the wrong species of trees on certain types of soils and sites.  Planted trees die.  Released trees die.  While all tree species will do well on  fine sandy loams, some will also do well on droughty sites; others will do well on wet sites--and vice versa.

In natural stands of mixed species, sometimes it's not obvious which tree species are best suited to a particular site, especially when the trees are young.  After they reach a certain age, it becomes more apparent which ones are happy there and which aren't.  If you're trying to grow valuable timber, it's important to know which species are likely to grow best on which sites.

Because all those silvicultural disasters were very costly, lots of research has been done to figure out why they happened.  My soil suitabiliy paper reviewed much of that research, and then applied it to data in Soil Conservation Service soil maps to see how site indices (a measure of adaptability) for different species on different soil series correlated with important soil characteristics: soil depth and texture, nature of rooting restriction, available water capacity and pH.

The results weren't so surprising.  Common sense and observation would have probably led to the same conclusions, but there it is in black and white anyway.  Ash and cherry do well on hardpan restricted soils; oak does well on rock restricted  soils. 

The Effects of Vegetation Removal on Water Quality

Environmentalists have spent a lot of time and energy trying to reduce the level of siltation in our streams and rivers from agriculture, construction, forestry and other land uses.  Municipal water supply managers are very anxious to minimize the adverse impacts of land use activities on the water that flows into reservoirs.

A review of the literature revealed that forestry activities do not necessarily have adverse impacts on water quality.  It all depends on how things are done.  The important thing is to minimize the area of exposed mineral soils during and after logging operations, especially near streams.  It's also important to minimize impacts at stream crossings so that banks don't erode.