ABSTRACT
Stem respiration (R s) plays a vital role in ecosystem carbon cycling. However, the measured efflux on the stem surface (E s) is not always in situ R s but only part of it. A previously proposed mass balance framework (MBF) attempted to explore the multiple partitioning pathways of R s, including sap-flow-transported and internal storage of R s, in addition to E s. This study proposed stem photosynthesis as an additional partitioning pathway to the MBF. Correspondingly, a double-chamber apparatus was designed and applied on newly sprouted Moso bamboo (Phyllostachys edulis) in leafless and leaved stages. R s of newly sprouted bamboo were twice as high in the leafless stage (7.41 ± 2.66 µmol m-2 s-1) than in the leaved stage (3.47 ± 2.43 µmol m-2 s-1). E s accounted for ~80% of R s, while sap flow may take away ~2% of R s in both leafless and leaved stages. Culm photosynthesis accounted for ~9% and 13% of R s, respectively. Carbon sequestration from culm photosynthesis accounted for approximately 2% of the aboveground bamboo biomass in the leafless stage. High culm photosynthesis but low sap flow during the leafless stage and vice versa during the leaved stage make bamboo an outstanding choice for exploring the MBF.
ABSTRACT
We report the synthesis and characterization of a novel series of main-chain boron-containing conjugated polymers (CPs), boron "doped" polyacetylenes (BPAs), which represent the first examples of main-chain boron-containing CPs without aromatic moieties within the polymer backbone, potentially enhancing electronic delocalization along the main-chain. These polymers are characterized by NMR, absorption and emission spectroscopy, cyclic voltammetry, theoretical calculation, and fluoride titration experiments, providing detailed understanding of the effects from different cross-conjugated side-chains on the physical and electronic properties of this new class of boron-containing polymers.
