# Chemical and biochemical characteristics of soils along transects in stands with different vegetation and successional characteristics in the Andrews Experimental Forest, 1996 ## Dataset - **Database Code:** SP021 - **Title:** Chemical and biochemical characteristics of soils along transects in stands with different vegetation and successional characteristics in the Andrews Experimental Forest, 1996 - **Abstract:** To better understand the effects vegetation has on forest soils, we established a number of sampling transects running from old-growth (OG) forests into stands with different vegetation or transects within different vegetation types without an OG component. Each transect was made up of 75 meter segments in both the OG and “treatment” stands. Soil samples and field observations were made at 5 meter-intervals along these segments. Where indicated, the OG portion of the transect acted as a pseudocontrol. The types of vegetation assemblages studied were: (1) a 26 year-old young stand (YS), (2) 6 sites showing normal to fast recovery (FAST) ranging in age from 29 to 36 years, (3) 5 sites showing slow recovery (SLOW) after clear-cutting ranging in age from 27 to 36 years, (4) 4 degraded (DEGRAD) sites ranging in age from 26 to 35 years, (5) 2 grass sites (GRASS), 26 years and undisturbed, and (6) a bracken fern site (FERN) aged at 26 years. Of these, the DEGRAD, GRASS and FERN sites showed much higher levels of denitrification potential than the other sites suggesting that mineralized fixed nitrogen was being lost from these sites at higher rates than the other vegetation types. Ectomycorrhizal mats were also essentially absent from sites as well. The concentration of living roots was highest in the YS and GRASS sites. The lowest concentrations of labile or biologically active organic carbon as measured by laboratory respiration rates, was found in the DEGRAD sites. The lowest levels of mineralizable (labile) organic nitrogen were found in the FERN site. Litter depth was lowest in the YS and GRASS sites and highest in the FERN site. There were a number of differences found between FAST and SLOW sites that reflected the different NNP activities in these stands. The concentration of ectomycorrhizal mats was greater in the FAST stands. Additionally, litter depth, field respiration rates were all greatest in the FAST stands, all of these patterns would be expected from stands with greater NPP. The concentration of mineralizable nitrogen, extractable ammonium and denitrification potentials were all lowest in the FAST stands suggesting that more organic nitrogen is being cycled and utilized by the faster growing trees. The higher concentration of mycorrhizal mats in these sites could provide the mechanism for cycling organic nitrogen a more rapid rate that in the SLOW sites where they are not as numerous. - **Keywords:** soil properties; succession; inorganic nutrients; plants; Long-Term Ecological Research (LTER); inorganic nutrients - **Temporal coverage:** 1996-07-01 to 1996-09-30 - **Principal Investigator:** Robert P. Griffiths ## Data Entities 1. SP02101 ## Entity 1: SP02101 ### Attribute list - **TRANSECT** — numeric(1.000000), range 29.0000 47.0000, number Transect number going from og control to treatment stand - **POSITION** — numeric(1.000000), range 0.0000 75.0000, number Position along each 75 meter leg; each 5 meters apart - **TREATMENT** — varchar, freetext Treatment type; OG=oldgrowth; DEGRAD=degraded; YS=young stand - **SOILTEMP** — numeric(0.100000), range 9.0000 25.0000, degrees Celsius Soil temperature measured with Licor - **AIRTEMP** — numeric(0.100000), range 8.0000 40.0000, degrees Celsius Air temperature measured with Licor - **LIGHT** — numeric(0.100000), range 0.0000 2000.0000, micromoles per square meter per second Amount of light measured with Licor - **MOIST** — numeric(0.100000), range 7.0000 200.0000, percent Percent moisture: ((wet-dry)/dry)*100 - **BULKDENS** — numeric(0.010000), range 0.0000 1.0000, grams per square centimeter Bulk density - **LITTER** — numeric(0.100000), range 0.0000 25.0000, centimeters Litter depth - **ROOTS** — numeric(0.001000), range 0.0000 3.0000, grams Dry mass of living roots in 4.7 x 10 cm core - **HYSTER** — numeric(1.000000), range 0.0000 100.0000, percent Percentage of core containing mycorrhizal mats like those of the genus Hysterangium - **GAUT** — numeric(1.000000), range 0.0000 100.0000, percent Percentage of core containing mycorrhizal mats like those of the genus Gautieria - **DENIT** — numeric(0.010000), range 0.0000 450.0000, nanograms per gram per hour Denitrification potential (dry weight basis, as N) - **EXAMM** — numeric(0.100000), range 0.0000 15.0000, micromoles per gram Extractable ammonium (dry weight basis) - **MINN** — numeric(0.100000), range 0.0000 70.0000, micromoles per gram Mineralizable nitrogen (dry weight basis) - **B_GLUC** — numeric(0.001000), range 0.0000 1.0000, micromoles per gram per hour Beta-glucosidase activity (dry weight basis) - **LABRESP** — numeric(0.100000), range 0.0000 200.0000, micrograms per gram per hour Laboratory respiration rates (dry weight basis) - **FLDRESP** — numeric(0.100000), range 0.0000 70.0000, grams per square meter per day Field respiration rates ## Attribute Definitions **AIRTEMP** Air temperature measured with Licor **BULKDENS** Bulk density **B_GLUC** Beta-glucosidase activity (dry weight basis) **DENIT** Denitrification potential (dry weight basis, as N) **EXAMM** Extractable ammonium (dry weight basis) **FLDRESP** Field respiration rates **GAUT** Percentage of core containing mycorrhizal mats like those of the genus Gautieria **HYSTER** Percentage of core containing mycorrhizal mats like those of the genus Hysterangium **LABRESP** Laboratory respiration rates (dry weight basis) **LIGHT** Amount of light measured with Licor **LITTER** Litter depth **MINN** Mineralizable nitrogen (dry weight basis) **MOIST** Percent moisture: ((wet-dry)/dry)*100 **POSITION** Position along each 75 meter leg; each 5 meters apart **ROOTS** Dry mass of living roots in 4.7 x 10 cm core **SOILTEMP** Soil temperature measured with Licor **TRANSECT** Transect number going from og control to treatment stand **TREATMENT** Treatment type; OG=oldgrowth; DEGRAD=degraded; YS=young stand