Assessment of carbon in woody plants and soil across a vineyard-woodland landscape

Abstract

BackgroundQuantification of ecosystem services, such as carbon (C) storage, can demonstrate the benefits of managing for both production and habitat conservation in agricultural landscapes. In this study, we evaluated C stocks and woody plant diversity across vineyard blocks and adjoining woodland ecosystems (wildlands) for an organic vineyard in northern California. Carbon was measured in soil from 44 one m deep pits, and in aboveground woody biomass from 93 vegetation plots. These data were combined with physical landscape variables to model C stocks using a geographic information system and multivariate linear regression.ResultsField data showed wildlands to be heterogeneous in both C stocks and woody tree diversity, reflecting the mosaic of several different vegetation types, and storing on average 36.8 Mg C/ha in aboveground woody biomass and 89.3 Mg C/ha in soil. Not surprisingly, vineyard blocks showed less variation in above- and belowground C, with an average of 3.0 and 84.1 Mg C/ha, respectively.ConclusionsThis research demonstrates that vineyards managed with practices that conserve some fraction of adjoining wildlands yield benefits for increasing overall C stocks and species and habitat diversity in integrated agricultural landscapes. For such complex landscapes, high resolution spatial modeling is challenging and requires accurate characterization of the landscape by vegetation type, physical structure, sufficient sampling, and allometric equations that relate tree species to each landscape. Geographic information systems and remote sensing techniques are useful for integrating the above variables into an analysis platform to estimate C stocks in these working landscapes, thereby helping land managers qualify for greenhouse gas mitigation credits. Carbon policy in California, however, shows a lack of focus on C stocks compared to emissions, and on agriculture compared to other sectors. Correcting these policy shortcomings could create incentives for ecosystem service provision, including C storage, as well as encourage better farm stewardship and habitat conservation.

Management of service crops for the provision of ecosystem services in vineyards: A review

“…Salomé et al (2016) found similar results for carbon content under permanent plant cover. Williams et al (2011) showed that scaling up vine management to landscape level, by maintaining wildlands in mosaic organization with vineyards, could be beneficial for increasing overall C stocks. As for carbon balance, it is important to take into account the global carbon footprint of vineyard cropping systems as mechanized soil tillage and service crop mowing can increase CO2 production from fossil fuels.…”

Variation in soil C and microbial functions across tree canopy projection and open grassland microenvironments

“…Agricultural landscapes that include perennial woody crops, such as vineyards, represent a major source of potential C storage or release (Williams et al, 2011). Almagro et al (2009) showed, under Mediterranean conditions, different soil CO 2 effluxes between land uses and, within uses, between beneath-and intercanopy sites.…”

Accounting for time-dependent changes in GHG emissions in the Ribeiro appellation (NW Spain): Are land use changes an important driver?

“…The results presented prove that a higher level of land management and farm stewardship could lead to the maximization of carbon stocks in vineyard landscapes, by implementing legislative actions to avoid the conversion of forest lands with high potential of carbon storage (Jackson et al, 2003). For instance, a study conducted by Williams et al (2011) showed that even old vines with high aboveground carbon content were only capable of retaining 25% of carbon as compared to surrounding wooded areas.…”

“…In addition, LUCs have allowed GHG emissions in Spain to be substantially lower in the past decades due to afforestation of many agricultural lands that were abandoned due to enforcements from the European Union's Common Agricultural Policy. However, viticulture has shown in previous studies to be a potential threat to the loss of natural habitat and species diversity, as well as a net emission of carbon to the atmosphere (Carlisle et al, 2006;Underwood et al, 2009;Williams et al, 2011). Therefore, the repeated exclusion of carbon storage and emissions due to LUCs, woody biomass in the vineyards and soil management from LCA studies may provoke an underestimation of the GHG emissions that are occurring in vineyard landscapes.…”