Multiscale Geographic Analysis of Biomass and Carbon in Viticulture within the Context of Agricultural Carbon Modeling in Southern Sacramento County, California

A series of three related investigations of vineyard organic carbon measurement is presented in the order of increasing geographic scope. This dissertation is written from a geography perspective and makes use of spatial analysis techniques common to geography and engineering, including the tools of geographic information systems (GIS) and computer aided design (CAD). The first investigation, Chapter 2, tests a new method for measuring perennial above ground biomass of Vitis vinifera (common grapevine). Data collected from grapevine trunks and cordons were used to study the accuracy of wood volume derived from laser scanning as compared with volume derived from analog measurements. A set of 10 laser scan datasets were collected for each of 36 vines from which volume was calculated using combinations of two, three, four, six and 10 scans. Likewise, analog volume measurements were made by submerging the vine trunks and cordons in water and capturing the displaced water. A regression analysis examined the relationship between digital and non-digital techniques among the 36 vines and found that the standard error drops rapidly as additional scans are added to the volume calculation process and stabilizes at the 4-view geometry with an average Pearson product moment correlation coefficient of 0.93. Estimates of digital volumes are systematically greater than those of analog volumes and can be explained by the manner in which each technique interacts with the vine tissue. This laser scanning technique yields a highly linear relationship between vine volume and tissue mass revealing a new, rapid and non-destructive method to remotely measure standing biomass. This application shows promise for use in other ecosystems such as orchards and forests.;The second investigation, Chapter 3, expands the scope from the individual vine to a vineyard. This investigation illustrates the contribution of viticultural carbon to that of agriculture at large which can be used for gauging offsets to fossil fuel carbon emissions. A spatial sample of vineyard organic carbon was collected using a nondestructive terrestrial laser scanning technique. Paired with mineral soil sampling and fruit yield, this approach provided a comprehensive spatial characterization of vineyard carbon storage. Vine perennial woody biomass was measured (n = 36) and soil was sampled to a depth of 1 m (n = 24), then combined with average fruit yield and found to total 3,160 Mg organic carbon for a 32.3 hectare vineyard. Vines averaged 1.93 kg of dry biomass (0.87 kg carbon) and when combined with root biomass, constituted 2% (60 Mg) of the total perennial vineyard carbon.;The third investigation, Chapter 4, presents and demonstrates a method for spatially segmenting a region for vineyard carbon modeling. This investigation bridges a methodology gap between generic small scale (spatially extensive) terrestrial carbon models and the locally diverse primary productivity inputs observed in Chapters 2 and 3. Physiographic data relevant to viticulture was collected and analyzed for the agricultural region of southern Sacramento County. The analysis yielded two viticulturally distinct areas that serve as spatial units that can be used for aggregating carbon model input data. The results were compared to existing descriptions of differences among the co-spatial American Viticultural Areas and found to be in agreement. The geographic boundaries generated in this analysis are more responsive to local conditions than those used in most terrestrial carbon model implementations and use publicly available data found in common GIS data formats.