Prescribed fire, a practice applied annually to about 10(6) hectares of forests in the southeastern United States, had limited effects on soils, nutrient cycling, and hydrologic systems of a coastal plain pine forest. Hydrologic fluxes of nitrogen, phosphorus, sulfur, and basic cations, from burned pine litter to ground and stream waters, are not likely to have appreciable impacts on water quality in the Atlantic and Gulf Coastal Plain.

The carbon cycle of a loblolly pine plantation in North Carolina was examined during its 12th through 16th years from planting. Net primary production during the study period averaged 2056 g C m year. With autotrophic respiration equal to 2068 g C, the calculated gross production was 4124 g C m year. Heterotrophic respiration of 694 g C m year resulted in net ecosystem production of 1362 g C m year. In carbon cycle comparisons between forest ecosystems, autotrophic respiration rates were found to be closely coupled to regional temperature.

Smokes produced by burning pine litter, green needles, and fuels of lower nitrogen content were drawn through dilute acid solutions which were then nesslerized in the presence and absence of titanous sulfate. Kjeldahl analyses of fuels and residues indicated that 62% of the nitrogen contained in pine litter and leaf materials was released by burning. No ammonia was detected in combustion gases. Only minor amounts (0.3% and less) of the nitrogen released by burning were detected by nesslerization (+TiSO4) of dilute acid solutions. We concluded that only small amounts (0.30 − 0.48 kg/ha‐1 for typical loblolly stands) of nitrogen released by forest fires could be returned to the soil via precipitation and be made available for tree growth. Most nitrogen in organic matter presumably is volatilized as nitrogen gas.

Loblolly pine (Pinus taeda L.) seedlings were grown from seed on core samples collected from surface soils of Lakeland loamy sand, Coxville loam, and Bayboro clay that had been compacted, puddled, or loosened. Seed germination was not affected by soil type or treatment, but seedlings became established with difficulty on clay cores and on heavily compacted cores of lighter texture. Top height and root length were not related to soil type, but seedlings grown on clay were significantly lighter than the other groups. Loosening the soil from its normal structure reduced growth on light‐textured soils, but stimulated it on clay soils. Compaction, whether at 3.5 or 10.5 kg cm‐2 of surface pressure, greatly reduced seedling size and weight. Small growth differences between compaction treatments indicated that even the smallest pressure applied reduced soil aeration and increased mechanical impedance to root growth to infavorable levels. There were negative linear relationships between root weight and penetration and densities ranging from 0.8 to 1.4 g cm‐3.

Bulk precipitation was collected for analysis of ionic constituents at eight rainfall stations over a 4‐year period at a 500‐ha watershed in the Lower Coastal Plain of South Carolina. Mean annual deposition rates of ions in greatest supply, Cl−, SO42− ‐S, Ca2+, and Na+, were respectively 14.2, 7.51, 5.69, and 5.66 kg/ha. Annual deposition rate for total inorganic N (NH4+ −N plus NO3− −N) was about 2.6 kg/ha and for orthophosphate‐P about 0.12 kg/ha. Spatial variation of annual depositions to the eight rainfall stations was smallest for SO42−, NO3−, and Ca2+, with coefficients of variation (CV) less than 10%. Variation of annual inputs to the eight collectors was intermediate for Mg2+, Cl−, H+, and Na+ with CV ranging between 13.9 and 21.5%, whereas the CV for annual inputs of NH4+, PO43−, and K+ exceeded 30%. Sample size estimates for this 500‐ha watershed indicated that 19 collectors should provide estimates of the annual bulk precipitation inputs within 10% of true means for 7 of 10 ions (SO42−, NO3−, Ca2+, Mg2+, Cl−, H+, and Na+) and that more than 35 collectors would be necessary to provide similar confidence intervals for annual inputs of NH4+, PO43−, and K+ (± 10% at P < 0.05). Although estimates of annual bulk precipitation inputs may be quite variable over local areas, control of sampling errors can be gained by increasing the number of collectors.