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This article discusses the relationship between root cortical parenchyma wall width (CPW) and plant functioning under drought conditions. The study found that thicker CPW in maize roots promotes growth and yield under suboptimal water and nitrogen supply. The authors used a functional-structural root anatomy model to predict the effects of increased CPW on root respiration and conducted field experiments to confirm their findings. They also identified potential genes associated with CPW changes and suggested that thicker CPW allows for deeper rooting, which enhances water uptake and plant performance under drought. The article highlights the importance of understanding root cortical cell structures and their impact on plant adaptation to stressful environments. [Extracted from the article]

(1) Background: Moso bamboo (Phyllostachys edulis (Carrière) J. Houz.) expansion has seriously altered the species composition and structure of adjacent forest ecosystems in subtropical regions. However, the shift in phosphorus (P) biogeochemical cycling has yet to be assessed, which is a critical gap considering the great variation in ecophysiological properties between invasive bamboo and the displaced native tree species. (2) Methods: We investigated and compared expansion-induced changes in P pools (plant, litter, and soil) and P fluxes (plant uptake and litterfall return) using paired sampling of the bamboo-dominated forest (BDF) and secondary evergreen broadleaved forest (EBF) at Jiangxi province's Dagang Mountain National Forest Ecological Station. (3) Results: Both the P storage of the plants and litter were significantly greater by 31.8% and 68.2% in the BDF than in the EBF, respectively. The soil total P and available P storage were 28.9% and 40.4% lower, respectively, in the BDF than in the EBF. Plant P uptake was 15.6% higher in the BDF than in the EBF, and the annual litter P return was 26.1% lower in the BDF than in the EBF due to higher P resorption efficiency for moso bamboo compared with evergreen broadleaved tree species. The ecosystem P cycling rate was reduced by 36.1% in the BDF compared with the EBF. (4) Conclusions: Moso bamboo expansion slowed the broadleaved forest ecosystem's P cycle rate, likely because moso bamboo has higher P-use efficiency, reserving more P in its tissues rather than returning it to the soil. The results from this study elucidate an understudied element cycle in the context of forest succession, demonstrating the ecosystem consequences related to bamboo invasion. [ABSTRACT FROM AUTHOR]

This document explores the multi-dimensionality of root traits in plants and the challenges in understanding them. It emphasizes the importance of considering various factors such as root biomass, physiological traits, and exudation in assessing root foraging capacity. The document also suggests the need to study community-level patterns and include other dimensions like root depth and chemical defense. Additionally, it highlights the significance of studying the relationship between root and leaf traits. The research was supported by the National Natural Science Foundation of China. [Extracted from the article]

Si availability may be altered by bamboo expansion when other trees are replaced by bamboo due to the influence of plant communities on the quantity of phytoliths and Si accumulation. It has been shown that Si availability can modify nutrient-use efficiency (e.g., N and P) of some Si-accumulating plants. However, it is unclear how Si availability might alter N uptake and assimilation between Si-accumulating plants such as bamboo compared to other species, particularly for different chemical forms such as ammonium (NH4+) and nitrate (NO3−). To explore the influences of Si availability on uptake and assimilation rates for different forms of inorganic N between bamboo and other trees, we selected one-year-old seedlings of bamboo (Phyllostachys pubescens) and three other native subtropical species, namely Phoebe bournei, Schima superba, and Cunninghamia lanceolata. We applied three levels of Si and 15N tracers in a pot experiment and then measured the concentrations of Si (total Si, soluble Si, and exchangeable Si), C, N (total N, NH4+-N, and NO3−-N), and N uptake and assimilation rates for both roots and leaves. We found that there were higher inorganic N root uptake and assimilation rates for bamboo compared to other species, likely due to higher biomass accumulation and quicker turnover of fine roots. Moreover, Si supply did not change the uptake preference for N forms or overall uptake and assimilation rates in most species; however, a high concentration of the Si supply slightly increased NO3−-N uptake and assimilation rates in fine roots and leaves of P. bournei, particularly immediately following the addition of Si. These results have implications for predicting the coexistence and competition between bamboo and other trees through the uptake and assimilation of different forms of inorganic N (i.e., high Si-accumulating plants compared to other plants), particularly when Si availability is altered in ecosystems. [ABSTRACT FROM AUTHOR]

The unbridled expansion of bamboo has imposed serious threats on ecosystem processes and functions. Considerable evidence indicates that bamboo invasions can alter plant-available soil nitrogen (N) pools and rates of N cycling, but the consequences of altered N availability for plant growth and community structure have thus far been poorly characterized. The primary soil-accessible N forms for most plants are ammonium (NH4+) and nitrate (NO3−), but plants differ in their ability to use the different N forms, and these differences can be related to their ecological characteristics and drive community structure. In this context, we evaluated the growth response, N uptake and interspecific competition in two subtropical species, Phyllostachys edulis (Carrière) J. Houzeau (Synonym Phyllostachys heterocycla Carrière) and Castanopsis fargesii Franch. dominant species of bamboo and secondary evergreen broad-leaved forests, respectively, under changing N availability in seedlings supplied with different N concentrations and NH4+/NO3− proportions, in vermiculite culture, in a controlled environment. The results show that (i) both species display an NH4+ preference at elevated N concentrations. The growth of P. edulis seedlings was strongly enhanced at increased ratios of NH4+ to NO3− especially at higher N concentrations, but to a much lesser extent in C. fargesii. (ii) NH4+ preference at the level of N uptake in both species was confirmed by the Non-invasive Micro-test Technology and by examining 15N signatures. Phyllostachys edulis had higher NH4+ net fluxes and N concentration under NH4+ treatments than C. fargesii. (iii) NH4+ at higher concentrations caused toxicity in both species as it inhibited root growth and even caused seedling death, but P. edulis had a higher NH4+-tolerance threshold (24 mM) than C. fargesii (16 mM). (iv) When mixed-species cultures were examined in an NH4+-rich medium, the growth of C. fargesii , but not P. edulis , was significantly inhibited compared with growth in monoculture. Therefore, P. edulis exhibited stronger plasticity and adaptation to changing N availability, whereas C. fargesii had low responsiveness and capacity to acclimate to soil N changes. Phyllostachys edulis displayed a significant competitive growth advantage compared with C. fargesii on NH4+-dominated substrates. [ABSTRACT FROM AUTHOR]