Partially removing or manipulating the vegetative overstory. This will reduce the amount of short-wave radiation received by the soil surface.  Redistributing logging debris to provide partial shade to microsites will accomplish the same objective.   Spot treatments are particularly useful in meeting this objective.

Mixing the organic horizons deeply into the minerals soil in coarse-textured soils.  This may avoid the usual extremes of soil surface temperatures and moisture that are characteristic of the undisturbed organic layer.  However, subsequent settling prior to planting to decrease the soil airspace that results from mixing may be required to increase thermal conductivity and volumetric heat capacity, and thus reduce temperature extremes.  This may be more critical in dense, fine, textured soils where little organic material was available for mixing.  This may involve waiting for a good rain (1 inch or 2.54 cm).

Nutrient availability

Mineral nutrients obtained from the soil are essential to all metabolic processes in trees.  In particular, root growth and development, and consequently, whole plant growth and development from germination onwards, are strongly influenced by soil fertility.  Nitrogen, phosphorous, and carbon are particularly important elements.  Rapid early growth of a seedling requires that considerable nitrogen resources, other than what is stored in the plant, be quickly found, absorbed, assimilated, and transported to areas in need.  Adding to this high nitrogen requirement for establishing  seedlings is the need to conserve the site's nutrient pool for a long-term stand productivity. see photo 8

Many forest stands occur on soils that are low in mineral nutrients; the most fertile zones are the surface organic layer and the first 10-20 cm of mineral soil.  Nutrient capital and availability are affected by the following:

Soil texture.  In coarse-textured sands, for example, the nutrient capital can be limited to organic layer, whereas soils with finer material tend to have a higher nutrient capital in the mineral horizons.  Soils with a low nutrient capital include extremely shallow soils, coarse-textured soils that are excessively drained, and soils in organic matter.   On some sites scalping of adjacent litter prior to mixing into the mineral soil (to a 50% organic, 50% mineral) may be money well spent.

Relative amounts of mineral soil and organic matter.  Nutrients stored in an organic form in the humus layer and in logging debris are returned to the soil after decomposing into a form usable to plants (via mineral processes).  Nitrogen, in particular, tends to occur in a less available organic form and, as a result, is often the most limiting of mineral nutrients.  Highly (humidified) organic materials consisting of buried leaves, wood, bark, and (humidified) forest-floor material play an important role in the regulation of nutrient cycling.  This finely divided organic matter favors several positive soil processes namely, soil aggregation, water holding capacity, aeration, cation exchange capacity, nutrient conservation, and can increase the soil's ability to retain nutrients.

Plants and soil organisms. Neighboring vegetation can influence nutrient availability directly by competing for soil nutrients, and indirectly by influencing soil moisture and temperature.   Some nitrogen-fixing plants such as alder can supply nitrogen to conifers.   The activity of soil insects, decay fungi, and other microorganisms is essential for soil fertility.  In particular, mycorrhizal fungi have a symbiotic relationship with tree roots and can enhance nitrogen and phosphorus uptake, particularly in low-phosphate soils.

Warning: If we are to have an impact on biodiversity and substainability we must increase our knowledge of soil microorganisms and their relationship with root development.  If we do not have an adequate balance of soil microorganisms we will not have a forest developing to full potential.  A lot more research is required.