Decomposition processes across a flooding gradient, with special reference to earthworm populations
Athens, Ga., Univ. of Georgia, Diss., 1983
Gespeichert in:
| 1. Verfasser: | |
|---|---|
| Format: | UnknownFormat |
| Sprache: | eng |
| Schlagworte: | |
| Online Zugang: | Katalogkarte der UB Frankfurt |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Tag hinzufügen | Zusammenfassung: | Athens, Ga., Univ. of Georgia, Diss., 1983 Forest floor leaf litter dynamics were investigated on four compartments (pine, hardwoods, moist hardwoods, and wet hardwoods) along a flooding gradient. Soil moisture levels and flooding frequency had major effects on litter. Leaf litterfall increased along the flooding gradient, while litter standing crops decreased along the flooding gradient. Litter decomposition, as measured by the litter bag technique, increased in the more mesic compartments. Measurement of lateral leaf movement rates along the forest floor using painted leaves revealed that scant litter was exported from the floodplain. A method was developed to account for both weight and nutrient additions to litter associated with soil deposition. Rates of soil deposition increased along the flooding gradient. This analysis revealed that soil deposition was the major source of iron and aluminum and an appreciable source of phosphorus and potassium for leaf litter. The sequence of nutrient residence times was K < Mg < P = Ca < Fe. The nutrient residency times decreased along the moisture gradient indicating that nutrient cycling increased in the swamp forest compared to the surrounding xeric forest. Earthworm populations were investigated in the four compartments along the flooding gradient also. Six species of earthworms were found: DIPLOCARDIA sp.1, EISENOIDES CAROLINENSIS, PHERETIMA DIFFRINGENS, BIMASTOS BEDDARDI, DIPLOPARDIA sp.2, and SPARGANOPHILUS sp.1. Soil moisture levels were the main determinates of earthworm distributions. Analysis of covariance revealed that soil organic matter, pH, and litter standing crop had little effect on earthworm populations or species distributions. Low earthworm populations of 1-8 worms m('-2) were found in the two xeric compartments, pine and hardwoods. Much larger earthworm populations of 126 (+OR-) 6 (std. err. of mean) animals m('-2) were found in the mesic compartments, moist hardwoods and wet hardwoods. Only one peregrine species, PHERETIMA DIFFRINGENS, was found on the site. The significance of habitat destruction and inter-specific competition on earthworm species distribution were discussed. |
|---|---|
| Beschreibung: | 148 S. |