What caused the atmosphere's CO2 content to rise during the last 8000 years?

[1] We make a case that the 20 ppm rise in atmospheric CO2 content over the last 8000 years was at least in part a consequence of the 500 Gt C increase in terrestrial biomass early in the present interglacial rather than of a 200 Gt C decrease in terrestrial biomass during the latter part of the Holocene as proposed by Indermuhle et al. [1999]. In support of this claim, we present new C-13 measurements from an Ontong Java Plateau box core, which do not reproduce the trend deduced from measurements on CO2 from the Taylor Dome ice core. In attempt to distinguish between scenarios put forth to accounting for the late Holocene rise in atmospheric CO2 content, we also made foraminifera shell weight measurements on three box cores from the Ontong Java Plateau. We were surprised to find that the early Holocene CaCO3 preservation event we sought was strongly depth dependent. The largest magnitude was at 4 km where CO3= ion concentrations appear to have been 30 mu mol/kg higher than today's and hence nearly as high as those in today's North Atlantic Deep Water.