Large plants enhance aboveground biomass in arid natural forest and plantation along differential abiotic and biotic conditions.

Big-sized trees, species diversity, and stand density affect aboveground biomass in natural tropical and temperate forests. However, these relationships are unclear in arid natural forests and plantations. Here, we hypothesized that large plants (a latent variable of tall-stature and big-crown, which indicated the effect of big-sized trees on ecosystem function and structure) enhance aboveground biomass in both arid natural forests and plantations along the gradients of climate water availability and soil fertility. To prove it, we used structural equation modeling (SEM) to test the influences of large plants located in 20% of the sequence formed by individual size (a synthetical value calculated from tree height and crown) on aboveground biomass in natural forests and plantations while considering the direct and indirect influences of species diversity as well as climatic and soil conditions, using data from 73 natural forest and 30 plantation plots in the northwest arid region of China. The results showed that large plants, species diversity, and stand density all increased aboveground biomass. Soil fertility declined aboveground biomass in natural forest, whereas it increased biomass in plantation. Although climatic water availability had no direct impact on aboveground biomass in both forests, it indirectly controlled the change of aboveground biomass via species diversity, stand density, and large plants. Stand density negatively affects large plants in both natural forests and plantations. Species diversity positively affects large plants on plantations but not in natural forests. Large plants increased slightly with increasing climatic water availability in the natural forest but decreased in plantation, whereas soil fertility inhibited large plants in plantation only. This study highlights the extended generality of the big-sized trees hypothesis, scaling theory, and the global importance of big-sized tree in arid natural forests and plantations.

[Compatibility mechanism of Gegen Qinlian Decoction in treatment of ulcerative colitis based on network pharmacology].

Gegen Qinlian Decoction(GQD) is commonly used for the clinical treatment of ulcerative colitis(UC) and other diseases, but its compatibility mechanism has not been elucidated systematically. In this study, the compatibility mechanism of GQD against UC was revealed based on the blood components in the mouse model of UC by network pharmacology. The targets of blood components of GQD were collected to construct a protein-protein interaction(PPI) network. The key targets were screened out according to the topological parameters of the network, and 16 core components were identified, such as puerarin, chrysin, berberine, and liquiritigenin, based on the key targets in the blood components. Functional enrichment analysis was performed on the key targets, and the regulatory network of the prescription was constructed, which elucidated the compatibility mechanism of the Chinese herbal drugs in the prescription at both target and pathway levels. The results showed that all the Chinese herbal drugs in GQD had heat-clearing and toxin-removing effects, and the four Chinese herbal drugs synergistically exerted their effects by co-regulating protooncogenes, such as FOS and JUN, and characteristically regulating signal transducer and activator of transcription 3(STAT3) and interleukin-6(IL-6). The pathway analysis revealed that GQD exerted heat-clearing and toxin-removing effects mainly by regulating the inflammatory response-related signaling pathways, such as Toll-like receptor, tumor necrosis factor(TNF), and mitogen-activated protein kinase(MAPK). Furthermore, the study revealed the synergistic effects of Chinese herbal drugs in GQD based on the TNF signaling pathway. The results showed that the sovereign drug Puerariae Lobatae Radix played a primary role in the regulation of targets in the TNF signaling pathway, the minister drugs Scutellariae Radix and Coptidis Rhizoma showed the synergistic effects with Puerariae Lobatae Radix, and the assistant and guiding drug Glycyrrhizae Radix et Rhizoma supported Puerariae Lobatae Radix in the key target NF-κB and the process of cell adhesion. The drugs in GQD showed good characteristics of compatibility in the TNF signaling pathway. This study is expected to provide the basis for the further exploration of the compatibility mechanism of GQD.

[Improving comprehensive retention rate of peppermint oil in freeze-dried preparation based on cyclodextrin inclusion technology].

The freeze-drying technique, characterized by low-temperature processing, is especially suitable for sensitive volatile oils with thermal instability. However, there are few studies focusing on the retention of volatile oils in the processing of freeze-dried preparations. This study evaluated the effects of different addition methods(adsorption, emulsification, solid dispersion, and inclusion) on the retention rate of the main components in peppermint oil, aiming to explore the application feasibility of freeze-dried preparations of volatile oils. Firstly, the addition method was determined based on the retention rates of menthol in four freeze-dried preparations. Secondly, an orthogonal test was designed to optimize the preparation process based on the characteristics of the preferred addition method. The results showed that the most suitable preparation form of peppermint oil was inclusion with beta-cyclodextrin(ß-CD), and the retention rate of menthol in freeze-drying was 86.36%. According to the two-step preparation process of inclusion and freeze-drying, we introduced the product of inclusion rate and retention rate, i.e., comprehensive retention rate, to determine the optimum processing parameters. The results showed that ß-CD/oil ratio of 7∶1, inclusion temperature of 40 ℃, and inclusion time of 2 h were the optimum processing parameters. The product prepared with these parameter had the comprehensive retention rate of 68.41%, retention rate of 92.53%, and inclusion rate of 73.93%. The inclusion compound was white powder with significantly increased solubility. The pre-paration process based on cyclodextrin inclusion in this study is stable and reliable and provides a new idea for ensuring the efficacy and stability of volatile components in freeze-dried preparations.

[Latitudinal variation in soil carbon, nitrogen and phosphorus pools across island forests and shrublands in eastern China]. / ä¸­å›½ä¸œéƒ¨æµ·å²›æ£®æž—å’ŒçŒä¸›åœŸå£¤ç¢³æ°®ç£·å »åˆ†åº“çš„çº¬åº¦å˜åŒ–.

Despite its monotonous structure, sea-island plays a crucial role in sustaining biodiversity and ecosystem functioning. The objectives of this study were to explore the altitudinal variation of soil carbon (C), nitrogen (N), and phosphorus (P) pools in forests across 14 islands spanning temperate zone (TZ), northern subtropical zone (NSZ), mid-subtropical zone (MSZ), and sou-thern subtropical zone (SSZ) in eastern China. The relationships of soil C and nutrient pools with climatic factors and plant species diversity were examined across islands. Our results showed that soil C, N and P pools differed significantly across climatic zones. Soil C and N pools were the lowest in TZ (49.35 and 1.08 t·hm-2) and the highest in NSZ (137.25 and 4.63 t·hm-2). Soil P pool was the lowest in SSZ (1.3 t·hm-2) and the highest in NSZ (5.19 t·hm-2). There were significant difference in soil C, N and P pools among vegetation types. Soil C, N and P pools in deciduous forests were significantly higher in subtropical than in temperate islands. Soil C and N pools in evergreen broadleaved forests did not differ among sub-climatic zones, and soil P pool was lower in SSZ than that in NSZ and MSZ. The interactions across mean annual temperature, mean annual precipitation, soil water content, and plant species diversity positively affected latitudinal variation in soil C, N, and P pools. Plant species diversity positively associated with soil N pool, but negatively linked with soil P pool. In conclusion, the latitudinal trend of soil C pool is different, but that of soil N and P pools are identical between sea-island and mainland. The main abiotic and biotic dri-vers of soil C, N and P pools are water availability, temperature and plant species diversity across sea-islands in eastern China.

Effects of the ephemeral stream on plant species diversity and distribution in an alluvial fan of arid desert region: An application of a low altitude UAV.

Biodiversity conservation, plant growth and spatial distribution of plant species are the central issues in contemporary community ecology. Ephemeral stream may influence soil properties, which in turn may determine biodiversity and function of an ecosystem in alluvial fan of arid desert region. Ephemeral stream is one of the most common natural disturbances, yet the effects of the ephemeral stream on plant communities in terms of species diversity and plant species distribution remain poorly studied. In this study, the information of species distribution, ephemeral stream beds ('washes'), and the characteristics of plant growth, i.e. height, crown area, were interpreted at different heights using the images of low altitude unmanned aerial vehicle (UAV). After that, soil properties such as soil texture (sand, silt and clay), soil water content, pH, soil organic matter, soil electric conductivity, soil bulk density and the percentage of gravel content, and their relationships with UAV data were assessed in order to explore the influences of ephemeral stream on species diversity, plant growth characteristics and species distribution in an alluvial fan of arid desert region. The results showed that deep-rooted plants were only distributed in washes whereas shallow-rooted plants were distributed in both washes and the outside of washes ('non-washes'). Species richness was significantly higher in washes than that in non-washes whereas the opposite pattern was true for abundance. Soil properties, plant height and crown area were higher in washes than that in non-washes. Plant height, crown area and the total number of individual plants increased with increasing wash width and per unit length of stream flow. This study highlights that the coupling factors of ephemeral stream, such as soil erosion, particle transport and sedimentation, can dramatically cause changes in soil properties and total number of individual plants, and hence, can influence species diversity, plant growth characteristics and spatial distribution of plant species in an alluvial fan of arid desert regions.