|
Objective 6 |
Objective 6. Describe the Physical Characteristics and Megafloral Components of the Soils. Organic horizons (or "litter layers") are remarkably well preserved. In swamp forests, the top 30 cm is little decomposed. Over brown (well-drained) mineral soil, there is up to 20-30 cm of well-preserved litter. Most of the foliage is identifiable to the genus level. There are abundant seeds, fruits and roots down to a diameter of 5 mm. Soil oxygen conditions in the mineral soils will be inferred from the presence or absence of mottling or gleying, and depending on microsite, both aerobic and anaerobic soils will be encountered. We assume that the deep accumulations of peat were the result of high water table, and that soils were saturated much of the year. Isotopic analyses (see above) may confirm these inferences of water availability. Within each .015 ha excavated, we will randomly locate five 0.5m2 soil plots which will be excavated quantitatively (e.g., Johnson et al. 1991). A complete inventory of leaf litter mass, root mass and diameter distribution, seeds and cones will be done. Mineral soil will be excavated to at least the bottom of the root zone, deeper if practical. Soil texture will be determined using standard procedures and water holding capacity of the mineral soil will be inferred from texture. |