Management alters C allocation in turfgrass lawns

• We measured biomass, NPP and C allocation in tall fescue managed as a home lawn.
• There was significant intraannual variation in lawn biomass.
• Management did not affect NPP, but had large effects on C allocation.

Turfgrass is a large fraction of land cover in urbanized areas around the world, but little information exists about basic ecological processes in lawns or the controls on these processes. Here, we characterize biomass carbon stocks and fluxes in tall fescue (Festuca arundinacea) appropriate for use on home lawns, managed with differing levels of irrigation, mowing height, and fertilization to test for effects of common management practices. Total standing biomass C (to 10 cm depth) averaged 6.04 Mg ha−1 over the course of the study, with slightly more C in roots than in stubble; management had little effect on the average standing biomass C pool, but there was substantial intraannual variation in biomass C stocks (>2 Mg C ha−1), and the pattern of variation was affected by all three management practices. Net primary production (NPP) averaged 4.50 Mg C ha−1 yr−1; management did not affect NPP, but had significant effects on how C was allocated to each component of production (roots, stubble, or clippings). Despite low standing biomass, turfgrass lawns generate a large annual flux of C, and the allocation of that flux is strongly modified by management.