346 REICHLE, DINGER, EDWARDS, HARRIS, AND SOLLINS 



their internal dynamics, and the ecological mechanisms through which they are 

 regulated (Reichle and Auerbach, 1972). Total-ecosystem analyses are based on 

 the concept that the landscape is organized into logical patterns of self- 

 sustaining, internally regulated, and dynamic components and that ecosystem 

 metabolism not only is fundamental to the integrity and stability of the system 

 itself but also is a viable approach to examining the carbon dynamics of large 

 segments of the biosphere. 



Although patterns are beginning to unfold for many ecological phenomena, 

 relatively little is known about the dynamics, regulation, and stability of carbon 

 cycles in natural ecosystems or about the quantitative differences and similarities 

 in function between various types of ecosystems. In the following analysis of a 

 temperate deciduous forest, a budget model of carbon pools in ecosystem 

 components and annual fluxes within the system has been developed to evaluate 

 the storage, turnover, and atmospheric exchange of carbon by a forested 

 landscape. 



SITE DESCRIPTION 



The study site is a second-growth, mesophytic, deciduous forest located on 

 karst topography within the U. S. Atomic Energy Commission reservation at 

 Oak Ridge, Tenn. (35 55 N, 84° 17 W). The forest is dominated by tulip poplar 

 interspersed with various oaks {Quercus velutina, Q. alba, Q. coccinea, Q. rubra, 

 and Q. prinus), short-leaf pine (Pinus echinata), and hickory (mainly Carya 

 tomentosa). Understory species include redbud (Cercis canadensis), flowering 

 dogwood {Cornus florida), and occasional black gum (Nyssa sylvatica), sour- 

 wood (Oxydendrum arboreum), red maple {Acer rubrum), and ash {Fraxinus 

 pennsylvanica). Virginia creeper (Parthenocissus quinque folia), woody hy- 

 drangea {Hydrangea arborescens), and Christmas fern {Polystichum acrosti- 

 cboides) account for approximately 90% of the herbaceous biomass, although 

 many other species are present. 



The forest is established on a deep alluvial Emory silt loam soil. Height of 

 the tallest tree is 30 m [42 cm diameter at breast height (DBH)] , and the age of 

 overstory is approximately 48 years. In 1962 the basal area of all trees >2.54 cm 

 DBH was 19.2 m 2 /ha (hectare) and in 1970, 22.1 m 2 /ha. The leaf-area index is 

 7.12. Mean annual temperature is 13.3 C, mean annual precipitation averages 

 126.5 cm, and total solar radiation averages 123.5 kcal cm" 2 year 1 . 



CARBON DISTRIBUTION AMONG ECOSYSTEM COMPONENTS 

 Autotroph Aboveground Standing Crop 



Analysis of the autotroph component of the forest includes components of 

 the overstory and understory trees and the herbaceous stratum. Estimates of 



