Ecological strategy of Phyllostachys heteroclada oliver in the riparian zone based on ecological stoichiometry

Abstract

The abnormality of seasonal water level fluctuation in the riparian zone causes various ecological and environmental problems, such as vegetation degradation, biodiversity reduction, soil erosion, and landscape transformation, thereby critically modifying the ecosystem structure and functions. This necessitates the development of a dominant vegetation zone with competitive potential. In this study, we investigated the content and distribution pattern of nutrient elements in each organ of the dominant bamboo species, Phyllostachys heteroclada, in the riparian zone. We also analyzed the morphological characteristics, root aeration tissue structure, root oxygen exchange capacity, ATP supply situation, and leaf PSII photosynthetic mechanism of two bamboo species (P. heteroclada and P. nigra) in the riparian zone. Compared with P. nigra, the roots of P. heteroclada formed well-developed oxygen storage and transport structure, i.e., aeration tissue, and exhibited root oxygen secretion in the waterlogging environment of the riparian zone, whereas the roots maintained a high ATP content through energy metabolism, thus benefiting mineral absorption and transport. Moreover, the accumulation of N, P, Ca, Mg, and Fe in the leaves of P. heteroclada was greater under waterlogging conditions than under non-waterlogging conditions, which is the basis for the efficient operation of the photosynthetic mechanism of the leaves. Compared with waterlogged P. nigra, the PSII electron acceptor QA of P. heteroclada leaves had a vigorous reducing ability and showed higher efficiency of light uptake energy as well as higher quantum yield indexes ϕ(Eo) and ϕ(Po). This study demonstrates that the ecological adaptive regulation strategies of P. heteroclada in the riparian zone are intrinsic driving factors affecting their stoichiometric characteristics, including changes in the absorption and transport of minerals caused by root aeration structure and energy metabolism. Moreover, carbon production and allocation may be caused by the stable photosynthetic mechanism and source-sink relationship of leaves. Through the synergistic regulation of different organs realizing their roles and functions, P. heteroclada developed ecological stoichiometry characteristics adapted to the riparian zone.

Patterns and drivers of plant carbon, nitrogen, and phosphorus stoichiometry in a novel riparian ecosystem

“…By contrast, for dynamic riparian ecosystems, a comprehensive analysis of plant C:N:P stoichiometry remains lacking until now, partly due to the lack of comprehensive data sets. For instance, several studies analyzed the patterns of plant C:N:P stoichiometry in riparian ecosystems, but either considered only a few species or focused only on plant leaves, ignoring plant stems and roots and their influences ( Huang et al., 2019 ; Zhou et al., 2021 ; Ding et al., 2022 ; Jing et al., 2022 ). This bias might be attributed to sampling difficulties or higher labor costs ( Xing et al., 2022 ), limiting our comprehensive understanding of plant adaptation strategies.…”

“…Nutrient partitioning among different plant organs reflects their trade-offs in accessing aboveground and belowground resources ( Hu et al., 2021 ). Riparian plants must effectively allocate limited resources among organs to withstand the combined stresses of inundation and nutrient limitation ( Jing et al., 2022 ). Therefore, gaining further insights into the elemental stoichiometric characteristics of different organs under varying inundation conditions is crucial for understanding riparian plant adaptation strategies.…”

Emerging Insights into the Roles of the Rhizome–Culm System in Bamboo Shoot Development through Analysis of Non-Structural Carbohydrate Changes

“…Nutrients integrated physiologically in the rhizomes are transported to the ramets together with water, affected by branching and the environment [ 16 , 17 , 18 , 19 , 20 ]. The direction of transport of substances in rhizomes is bidirectional and related to source–sink relationships, either along the rhizomes or going through rhizomes, so that parent bamboos of every age may provide nutrients for bamboo shoots [ 17 , 21 , 22 ]. The source of nutrients in bamboo shoots during such rapid growth remains unknown until the influence of different age parent culms is clarified.…”