High Foliar and Soil Nitrogen Concentrations in Central Appalachian Forests

Regional topography and climate variation yield differences in ecosystem attributes that make spa-tially scaled estimates of forest productivity chal-lenging. Foliar nitrogen is a primary indicator of forest ecosystem productivity and is used in regional estimates of terrestrial productivity, but this char-acteristic has not been well described in the Central Appalachian region. Here we describe foliar and soil N variation among species and elevations at two spatial scales in the Central Appalachian region: (1) across the Elklick watershed in the Fernow Experi-mental Forest and (2) across the state of West Vir-ginia. We found higher foliar N concentrations at both scales than those previously reported for other temperate forest regions. Canopy and soil nitrogen concentrations were also much greater in the Fer-now than generally observed across West Virginia. Soil N concentrations in the Fernow were two times greater than those observed across West Virginia. Species-related differences were observed at both spatial scales, but were not always consistent. Can-opy N ranges are generally consistent across eleva-tions throughout the state of West Virginia, but should be scaled according to species-related eleva-tion effects for studies that estimate productivity differences in response to harvest or changing spe-cies composition. The incongruence of foliar and soil N concentrations at the Fernow Experimental Forest are not explained by elevation or species composi-tion, but are likely a consequence of greater histor-ical N and H+ deposition relative to the surrounding West Virginia region. Key words: soil nitrogen; foliar N; Central Appa-lachian; West Virginia; hardwood species; spatial variation; ecosystem scaling; canopy N; eastern U.S. hardwood forests; topography; Fernow Experi-mental Forest