Summary Strategies for deep soil water acquisition (WAdeep) are critical to a species’ adaptation to drought. However, it is unknown how WAdeep determines the abundance and resource economy strategies of understorey shrub species. With data from 13 understorey shrub species in subtropical coniferous plantations, we investigated associations between the magnitude of WAdeep, the seasonal plasticity of WAdeep, midday leaf water potential (Ψmd), species abundance and resource economic traits across organs. Higher capacity for WAdeep was associated with higher intrinsic water use efficiency, but was not necessary for maintaining higher Ψmd in the dry season nor was it an ubiquitous trait possessed by the most common shrub species. Species with higher seasonal plasticity of WAdeep had lower wood density, indicating that fast species had higher plasticity in deep soil resource acquisition. However, the magnitude and plasticity of WAdeep were not related to shallow fine root economy traits, suggesting independent dimensions of soil resource acquisition between deep and shallow soil. Our results provide new insights into the mechanisms through which the magnitude and plasticity of WAdeep interact with shallow soil and aboveground resource acquisition traits to integrate the whole‐plant economic spectrum and, thus, community assembly processes.

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Large-scale Quercus variabilis natural secondary forests are protected under the Natural Forest Protection (NFP) program in China to improve the ecological environment. However, information about nutrient characteristics and carbon (C) storage is still lacking. Plant biomass and C, nitrogen (N) and phosphorus (P) stoichiometry of tree tissues, shrubs, herbs, litter, and soil were determined in young, middle-aged, near-mature and mature Quercus variabilis secondary forests in the Qinling Mountains, China. Tree leaf N and P concentrations indicated that the N-restricted situation worsened with forest age. The per hectare biomass of trees in decreasing order was near-mature, mature, middle-aged, then young stands. The majority of the biomass was in the stems (44.88-48.15%), followed by roots (24.54-28.68%), and branches (10.15-14.16%), and leaves made up the lowest proportion (2.86-3.55%) of trees. C storage at plant layer increased significantly with age, reaching maximum values in near-mature stand (100.4 Mg·ha −1 ) and then decreasing in mature stands. Soil C storage at a depth of 0 to 100 cm was 82.8, 96.8, 85.8, 104.2 Mg·ha −1 , and C storage of forest ecosystem was 122.8, 163.0, 184.9, 178.3 Mg·ha −1 in young, middle-aged, near-mature, mature stands, respectively. There were significant correlations between biomass and C, N, P stoichiometry in different layers, especially in young stands.

The degree of plant iso/anisohydry is a popular framework for characterising species-specific drought responses. However, we know little about associations between below-ground and above-ground hydraulic traits as well as the broader ecological implications of this framework.For 24 understory shrub species in seasonally dry subtropical coniferous plantations, we investigated contributions of the degree of isohydry to species' resource economy strategies, abundance, and importance value, and quantified the hydraulic conductance (K h ) of aboveground and below-ground organs, magnitude of deep water acquisition (WA deep ), shallow absorptive root traits (diameter, specific root length, tissue density), and resource-use efficiencies (A max , maximum photosynthesis rate; PNUE, photosynthetic nitrogen-use efficiency).The extreme isohydric understory species had lower wood density (a proxy for higher growth rates) because their higher WA deep and whole-plant K h allowed higher A max and PNUE, and thus did not necessarily show lower abundance and importance values. Although species' K h was coordinated with their water foraging capacity in shallow soil, the more acquisitive deep roots were more crucial than shallow roots in shaping species' extreme isohydric behaviour.Our results provide new insights into the mechanisms through which below-ground hydraulic traits, especially those of deep roots, determine species' degree of isohydry and economic strategies.

Hydraulic capacitance and carbohydrate storage are two drought adaptation strategies of woody angiosperms. However, we currently lack information on their associations and how they are associated with species’ degree of isohydry. We measured total stem xylem non-structural carbohydrate (NSC) concentration in the dry and wet seasons, xylem hydraulic capacitance, native leaf water potentials, pressure-volume curve parameters, and photosynthetic performance in 24 woody understory species differing in their degree of isohydry. We found a trade-off between xylem water and carbohydrate storage both in storage capacitance and along a spectrum of isohydry. Species with higher hydraulic capacitance had lower native NSC storage. The less isohydric species tended to show greater NSC depletion in the dry season and have more drought-tolerant leaves. In contrast, the more isohydric species had higher hydraulic capacitance, which may enhance their drought avoidance capacity. In these species, leaf flushing in the wet season and higher photosynthetic rates in the dry season resulted in accumulation rather than depletion of NSC in the dry season. Our results provide new insights into the mechanisms through which xylem storage functions determine co-occurring species’ drought adaptation strategies and improve our capacity to predict community assembly processes under drought.

For feature subset optimization problems in text categorization, the GATS strategy which combines the genetic algorithm with taboo search algorithm is proposed in this paper to be applied to text categorization to realize the dimensionality reduction of the feature space. The experiments show that the application of this method to select the characteristics of the text can not only maintain the advantages of the GA and the TS algorithm themselves, but also improve the classification accuracy of the text.

Aster pekinensis is a perennial herb that distributes widely in China, Korea, and Eeastern Russia. The complete plastome of A. pekinensis is reported here. It is a circular molecular of 152,815 bp in length and consists of a large single-copy region (LSC: 84,530 bp), a small single-copy region (SSC: 18,219 bp), and two inverted repeats (IR: 25,033 bp) regions. GC content is 37.3%. This plastome encodes 113 unique genes, including 79 protein-coding genes, 30 tRNAs, and 4 rRNAs. Phylogenomic analysis of 17 plastomes within Aster and closely related genera revealed that A. pekinensis was sister to the clade comprising A. flaccidus and A. altaicus.