Variations and trade-offs in leaf and culm functional traits among 77 woody bamboo species.

BACKGROUND: Woody bamboos are the only diverse large perennial grasses in mesic-wet forests and are widely distributed in the understory and canopy. The functional trait variations and trade-offs in this taxon remain unclear due to woody bamboo syndromes (represented by lignified culm of composed internodes and nodes). Here, we examined the effects of heritable legacy and occurrence site climates on functional trait variations in leaf and culm across 77 woody bamboo species in a common garden. We explored the trade-offs among leaf functional traits, the connection between leaf nitrogen (N), phosphorus (P) concentrations and functional niche traits, and the correlation of functional traits between leaves and culms. RESULTS: The Bayesian mixed models reveal that the combined effects of heritable legacy (phylogenetic distances and other evolutionary processes) and occurrence site climates accounted for 55.10-90.89% of the total variation among species for each studied trait. The standardized major axis analysis identified trade-offs among leaf functional traits in woody bamboo consistent with the global leaf economics spectrum; however, compared to non-bamboo species, the woody bamboo exhibited lower leaf mass per area but higher N, P concentrations and assimilation, dark respiration rates. The canonical correlation analysis demonstrated a positive correlation (ρ = 0.57, P-value < 0.001) between leaf N, P concentrations and morphophysiology traits. The phylogenetic principal components and trait network analyses indicated that leaf and culm traits were clustered separately, with leaf assimilation and respiration rates associated with culm ground diameter. CONCLUSION: Our study confirms the applicability of the leaf economics spectrum and the biogeochemical niche in woody bamboo taxa, improves the understanding of woody bamboo leaf and culm functional trait variations and trade-offs, and broadens the taxonomic units considered in plant functional trait studies, which contributes to our comprehensive understanding of terrestrial forest ecosystems.

Application of Bamboo Plants in Nine Aspects.

Bamboo forests are undoubtedly one of the most abundant nontimber plants on Earth and cover a wide area of tropical and subtropical regions around the world. This amazing plant has unique rapid growth and can play an important role in protecting our planet from pollution and improving the soil. Bamboo can be used as a biofuel, food, and for architecture and construction applications and plays a large role in the local economy by creating job opportunities. The aim of this paper is to review the extraordinary tropical plant bamboo by explaining the mechanisms related to the growth and strength of bamboo and identifying ways to utilize bamboo in industry, employment, climate change mitigation, and soil erosion reduction.

Comparison of metaxylem vessels and pits in four sympodial bamboo species.

The anatomical morphologies of vessel elements and pits of bamboo plants are unique, however, intensive research about vessel elements and pits in bamboo species is very scarce. The vessel elements and pits of four sympodial bamboo species were analyzed by light microscopy and environmental scanning electron microscopy (ESEM). Results show that the length and width of vessel elements were significantly different across bamboo species. The simple (main type), scalariform, and reticulate perforation plates were discovered on the end of vessel elements. The four species also displayed distinct pit forms. Characteristics of vessel elements, perforation plates, and the shape and size of pit apertures were examined separately for their potential relationship of bamboo structure and function.

[Phosphate solubilizing characteristics of Talaromyces aurantiacus and its growthpromoting effect on Phyllostachys edulis seedlings]. / ä¸€æ ªé‡‘é»„è“çŠ¶èŒè§£ç£·ç‰¹æ€§åŠå ¶å¯¹æ¯›ç«¹çš„ä¿ƒç”Ÿæ•ˆåº”.

To investigate phosphate-solubilizing characteristics and plant growth-promoting effect of Talaromyces aurantiacus (JXBR04) from Phyllostachys edulis rhizosphere soil, the influence of culture time, carbon sources, nitrogen sources, initial pH, liquid filling volume, and salt ions on phosphate solubilizing ability of strain JXBR04 were examined. The capability to solubilize different types of mineral phosphate was detected using a liquid fermentation method. A pot experiment was conducted to evaluate the effects of strain JXBR04 in promoting the growth of Ph. edulis seedlings. The results showed that strain JXBR04 displayed the highest phosphate-dissolving capacity when the cultivation period was 7 days, the initial pH reached 3.5, the volume of liquid was 1/5 or 2/5, and the NaCl concentration was 0 or 1.0 g·L-1. The phosphate-dissolving ability of the strain was the highest when using sugar as carbon source and yeast powder as nitrogen source. The strain had the greatest ability to solubilize CaHPO4 with 1304.04 mg·L-1, followed by Ca3(PO4)2 and FePO4. We found that available nutrients, leaf, stem, and root phosphorus contents in rhizospheric soil significantly increased in Ph. edulis after 180 days of inoculation with strain JXBR04. In addition, Ph. edulis inoculated with strain JXBR04 had 28.1%, 28.3%, and 51.5% higher ground diameter, seedling height, and biomass accumulation than that without JXBR04, respectively. Our findings suggested that T. aurantiacus has the potential to be applied as environment-friendly biofertilizers in maso bamboo forest in the acid soil in southern China.

Effects of climate and forest structure on palms, bromeliads and bamboos in Atlantic Forest fragments of Northeastern Brazil / Efeitos do clima e da estrutura da vegetação em palmeiras, bromélias e bambus em fragmentos de Mata Atlântica no nordeste brasileiro

Abstract Palms, bromeliads and bamboos are key elements of tropical forests and understanding the effects of climate, anthropogenic pressure and forest structure on these groups is crucial to forecast structural changes in tropical forests. Therefore, we investigated the effects of these factors on the abundance of these groups in 22 Atlantic forest fragments of Northeastern Brazil. Abundance of bromeliads and bamboos were assessed through indexes. Palms were counted within a radius of 20 m. We also obtained measures of vegetation structure, fragment size, annual precipitation, precipitation seasonality and human population density. We tested the effects of these predictors on plant groups using path analysis. Palm abundance was higher in taller forests with larger trees, closed canopy and sparse understory, which may be a result of the presence of seed dispersers and specific attributes of local palm species. Bromeliads were negatively affected by both annual precipitation and precipitation seasonality, what may reflect adaptations of these plants to use water efficiently, but also the need to capture water in a regular basis. Bamboos were not related to any predictor variable. As climate and forest structure affected the abundance of bromeliads and palms, human-induced climatic changes and disturbances in forest structure may modify the abundance of these groups. In addition, soil properties and direct measurements of human disturbance should be used in future studies in order to improve the predictability of models about plant groups in Northeastern Atlantic Forest.

Resumo Palmeiras, bromélias e bambus são importantes elementos das florestas tropicais e, entender os efeitos do clima, pressão antrópica e estrutura da floresta nesses grupos é crucial para prever alterações estruturais em florestas tropicais. Portanto, nós investigamos os efeitos desses fatores na abundância desses grupos vegetais em 22 fragmentos de Mata Atlântica no nordeste brasileiro. Abundâncias de bromélias e bambus foram registradas através de índices. Palmeiras foram contadas em um raio de 20 m. Nós também obtemos medidas da estrutura da vegetação, tamanho de fragmento, precipitação anual, sazonalidade na precipitação e densidade populacional humana. Nós testamos os efeitos desses preditores nos grupos vegetais através de análises de caminhos. A abundância de palmeiras foi maior em florestas mais altas, com árvores mais grossas, dossel fechado e sub-bosque aberto, o que deve refletir a presença de dispersores de sementes e atributos específicos das espécies de palmeiras locais. Bromélias foram negativamente afetadas pela precipitação anual e pela sazonalidade na precipitação, o que deve refletir adaptações dessas plantas para o uso eficiente da água, mas também a necessidade de captar água regularmente. Bambus não estiveram relacionados com nenhum dos preditores avaliados. Dado que clima e estrutura florestal afetaram a abundância de bromélias e palmeiras, as mudanças climáticas e distúrbios na estrutura das matas causados por ações antrópicas podem alterar a abundância desses grupos. Adicionalmente, propriedades do solo e medidas diretas de distúrbios antrópicos devem ser usadas em estudos futuros para melhorar o poder preditivo dos modelos sobre a abundância de plantas na Mata Atlântica do nordeste brasileiro.

Effects of climate and forest structure on palms, bromeliads and bamboos in Atlantic Forest fragments of Northeastern Brazil.

Palms, bromeliads and bamboos are key elements of tropical forests and understanding the effects of climate, anthropogenic pressure and forest structure on these groups is crucial to forecast structural changes in tropical forests. Therefore, we investigated the effects of these factors on the abundance of these groups in 22 Atlantic forest fragments of Northeastern Brazil. Abundance of bromeliads and bamboos were assessed through indexes. Palms were counted within a radius of 20 m. We also obtained measures of vegetation structure, fragment size, annual precipitation, precipitation seasonality and human population density. We tested the effects of these predictors on plant groups using path analysis. Palm abundance was higher in taller forests with larger trees, closed canopy and sparse understory, which may be a result of the presence of seed dispersers and specific attributes of local palm species. Bromeliads were negatively affected by both annual precipitation and precipitation seasonality, what may reflect adaptations of these plants to use water efficiently, but also the need to capture water in a regular basis. Bamboos were not related to any predictor variable. As climate and forest structure affected the abundance of bromeliads and palms, human-induced climatic changes and disturbances in forest structure may modify the abundance of these groups. In addition, soil properties and direct measurements of human disturbance should be used in future studies in order to improve the predictability of models about plant groups in Northeastern Atlantic Forest.

Characterization and primary functional analysis of a bamboo NAC gene targeted by miR164b.

KEY MESSAGE: PeSNAC1 , a stress-related NAC1 from Phyllostachys edulis , was characterized. Ectopic expression in Arabidopsis indicated that PeSNAC1 together with ped -miR164b participated in the regulation of organ boundaries and stress tolerance. NAC (NAM, ATAF1/2 and CUC2) participates in many different processes regulating plant growth, development, and stress response. A total of 125 NAC genes have been predicted in moso bamboo (Phyllostachys edulis), but their roles are poorly understood. PeSNAC1 targeted by ped-miR164b was focused for further study. The cleavage of PeSNAC1 mRNA guided by ped-miR164b was validated using RLM-5' RACE. Tissue-specific expression analysis demonstrated that ped-miR164b had a declining trend from root, sheath, leaf, to that of stem, which was opposite to that of PeSNAC1. Transgenic Arabidopsis plants overexpressing either PeSNAC1 (OX-PeSNAC1) or, ped-miR164b (OX-ped-miR164b) driven by the CaMV35S promoter were generated. OX-ped-miR164b plants showed similar phenotype of cuc2 mutants whose growth was seriously suppressed. Compared with Col-0, sense OX-PeSNAC1 plants grew rapidly and flowered earlier, whereas antisense plants grew slowly and exhibited delayed flowering. Sense OX-PeSNAC1 plants had the greatest number of lateral roots, while antisense OX-PeSNAC1 and OX-ped-miR164b plants had fewer lateral roots than Col-0. Under NaCl and PEG6000 stresses, survival rates were higher and F v/F m values declined more slowly in sense OX-PeSNAC1 plants than in Col-0, with lower survival rates and a more rapid decrease in F v/F m values conversely observed in antisense OX-PeSNAC1 and OX-ped-miR164b plants. These findings indicated that ped-miR164b-targeted PeSNAC1 may play key roles in plant development and tolerance to salinity and drought stresses.

Molecular Origin of Strength and Stiffness in Bamboo Fibrils.

Bamboo, a fast-growing grass, has a higher strength-to-weight ratio than steel and concrete. The unique properties of bamboo come from the natural composite structure of fibers that consists mainly of cellulose microfibrils in a matrix of intertwined hemicellulose and lignin called lignin-carbohydrate complex (LCC). Here, we have used atomistic simulations to study the mechanical properties of and adhesive interactions between the materials in bamboo fibers. With this aim, we have developed molecular models of lignin, hemicellulose and LCC structures to study the elastic moduli and the adhesion energies between these materials and cellulose microfibril faces. Good agreement was observed between the simulation results and experimental data. It was also shown that the hemicellulose model has stronger mechanical properties than lignin while lignin exhibits greater tendency to adhere to cellulose microfibrils. The study suggests that the abundance of hydrogen bonds in hemicellulose chains is responsible for improving the mechanical behavior of LCC. The strong van der Waals forces between lignin molecules and cellulose microfibril is responsible for higher adhesion energy between LCC and cellulose microfibrils. We also found out that the amorphous regions of cellulose microfibrils are the weakest interfaces in bamboo fibrils. Hence, they determine the fibril strength.

Use of gold nanoparticles to detect water uptake in vascular plants.

Direct visualization of water-conducting pathways and sap flows in xylem vessels is important for understanding the physiology of vascular plants and their sap ascent. Gold nanoparticles (AuNPs) combined with synchrotron X-ray imaging technique is a new promising tool for investigating plant hydraulics in opaque xylem vessels of vascular plants. However, in practical applications of AuNPs for real-time quantitative visualization of sap flows, their interaction with a vascular network needs to be verified in advance. In this study, the effect of AuNPs on the water-refilling function of xylem vessels is experimentally investigated with three monocot species. Discrepancy in the water uptakes starts to appear at about 20 min to 40 min after the supply of AuNP solution to the test plant by the possible gradual accumulation of AuNPs on the internal structures of vasculature. However conclusively, it is observed that the water-refilling speeds in individual xylem vessels are virtually unaffected by hydrophilically surface-modified AuNPs (diameter ∼20 nm). Therefore, the AuNPs can be effectively used as flow tracers in the xylem vessels in the first 20∼30 min without any physiological barrier. As a result, AuNPs are found to be useful for visualizing various fluid dynamic phenomena occurring in vascular plants.

Crack propagation in bamboo's hierarchical cellular structure.

Bamboo, as a natural hierarchical cellular material, exhibits remarkable mechanical properties including excellent flexibility and fracture toughness. As far as bamboo as a functionally graded bio-composite is concerned, the interactions of different constituents (bamboo fibers; parenchyma cells; and vessels.) alongside their corresponding interfacial areas with a developed crack should be of high significance. Here, by using multi-scale mechanical characterizations coupled with advanced environmental electron microscopy (ESEM), we unambiguously show that fibers' interfacial areas along with parenchyma cells' boundaries were preferred routes for crack growth in both radial and longitudinal directions. Irrespective of the honeycomb structure of fibers along with cellular configuration of parenchyma ground, the hollow vessels within bamboo culm affected the crack propagation too, by crack deflection or crack-tip energy dissipation. It is expected that the tortuous crack propagation mode exhibited in the present study could be applicable to other cellular natural materials as well.

[Effects of elevated CO2 concentration on physiological characters of three dwarf ornamental bamboo species].

By using open-top chambers (OTCs) to simulate the scenes of elevated CO2 concentrations [500 micromol x mol(-1) (T1) and 700 micromol x mol(-1) (T2)], and taking ambient atmospheric CO2 concentration as the control (CK), this paper studied the effects of elevated CO2 concentration on the lipid peroxidation and anti-oxidation enzyme system in Indocalamus decorus, Pleioblastus kongosanensis, and Sasa glabra leaves. After 103 days treatment, the O2(-)* and MDA contents, relative electron conduction, and soluble sugar content in the three dwarf ornamental bamboo species leaves in T1 had no obvious change, but the activities of anti-oxidation enzymes (SOD, POD, CAT, and APX) changed to a certain extent. In T2, the MDA content and relative electron conduction had no obvious change, but the O2(-)* and soluble sugar contents and the anti-oxidation enzymes activities changed obviously. The adaptation capacity of the three bamboo species to elevated CO2 concentration was in the order of I. decorus > P. kongosanensis > S. glabra.

[Retrieval of leaf area index of moso bamboo forest with Landsat Thematic Mapper image based on PROSAIL canopy radiative transfer model].

The PROSAIL canopy radiative transfer model was used to establish leaf area index (LAI) and canopy reflectance lookup-table for Moso bamboo forest. The combination of Landsat Thematic Mapper (TM) image and this model was then used to retrieve LAI. The results demonstrated that the sensitivity of the input parameters in the PROSAIL model decreased in order of LAI >chlorophyll content (C(ab)) > leaf structure parameters (N) > mean leaf angle (ALA) > equivalent water thickness (C(w)) > dry matter content (C(m)). The most sensitive factors LAI and C(ab) were then used to construct the LAI-canopy reflectance lookup-table. The LAI estimates from the PROSAIL model had good agreement with the reference data, with the coefficient of determination (R2) reached 0.90. The root mean square error (RMSE) and relative RMSE were 0.58 and 13.0%, respectively. However, the mean LAI estimate was higher than the observed value.

A mathematical model with pulse effect for three populations of the giant panda and two kinds of bamboo.

A mathematical model for the relationship between the populations of giant pandas and two kinds of bamboo is established. We use the impulsive perturbations to take into account the effect of a sudden collapse of bamboo as a food source. We show that this system is uniformly bounded. Using the Floquet theory and comparison techniques of impulsive equations, we find conditions for the local and global stabilities of the giant panda-free periodic solution. Moreover, we obtain sufficient conditions for the system to be permanent. The results provide a theoretical basis for giant panda habitat protection.

Bamboo dominance reduces tree regeneration in a disturbed tropical forest.

Human disturbance may change dominance hierarchies of plant communities, and may cause substantial changes in biotic environmental conditions if the new dominant species have properties that differ from the previous dominant species. We examined the effects of bamboos (Bambusa tulda and Cephalostachyum pergracile) and their litter on the overall woody seedling abundance, species richness and diversity in a mixed deciduous forest in northeastern Thailand. These bamboo species are gaining dominance after human disturbance. Our results show that seedling abundance and species richness were reduced by bamboo canopies. Seedling abundance and species diversity under bamboo canopies were affected by bamboo litter, whereas seedling abundance and species diversity outside bamboo canopies did not respond to the mixed-tree litter manipulation. Removal of bamboo litter increased seedling abundance and species diversity. However, bamboo litter addition did not affect seedling abundance or species diversity compared to either control or litter removal. This may indicate that the effect of natural amount of bamboo litter is as high as for litter addition in preventing seedling establishment by woody species and hence in minimizing resource competition. We conclude that undergrowth bamboos and their litter affect tree seedling regeneration differently from mixed-tree litter, causing changes in plant community composition and species diversity. Increased human disturbance, causing a shift in dominance structure of these forests, may result in a concomitant reduction in their overall woody species abundance, richness and diversity. Thus, management of bamboos by controlling their distribution in areas of high bamboo density can be an important forest restoration method.

The investigation of noise attenuation by plants and the corresponding noise-reducing spectrum.

As noise pollution is becoming more and more serious, many researchers are studying the noise attenuation effect provided by plants. This article examines six kinds of evergreens as research subjects so as to compare the different arrangements and densities of plants and their effect on noise attenuation. The authors studied the relationship between each of the plant's characteristics (the characteristics include leaf area, leaf fresh weight, leaf tactility, and leaf shape) and their average relative noise attenuation (deltaLAep). The authors then generated the noise-reducing spectrum of the six plants. The results show that there is a notable difference in noise-reducing effects for low frequency and high frequency (p < .05) when the plants are arranged differently. Also, every plant demonstrates a specific noise-reducing spectrum. By quantifying noise attenuation characteristics and abilities of plants, the authors combine noise attenuation species to achieve the mutual benefits of plant varieties and establish an ecotypic sound barrier model with effective density and arrangement.

Genets of dwarf bamboo do not die after one flowering event: evidence from genetic structure and flowering pattern.

Dwarf bamboos in the genus Sasa are believed to be long-lived, synchronously flowering, and monocarpic plants. However, the monocarpy of dwarf bamboo has not been confirmed, because whether all ramets within one genet flower at the same time cannot be determined without differentiating the genetic structure among ramets. This study aims to evaluate the reproductive traits of Sasa pubiculmis by verifying the monocarpy and physiological integration between flowering ramets and non-flowering ramets during a 4-year flowering period. One genotypically identified genet, which covered an area of approximately 3 ha, had both flowering and non-flowering patches of ramets during the 4-year flowering period (2004-2007). A fraction of the flowering genet remained non-flowering during the 4 years of observation, and did not die after mass flowering. Flowering ramets were physically connected to non-flowering ramets via rhizomes, and assimilated (13)C was allocated from non-flowering ramets to flowering ramets. Consequently, we clarified that this dwarf bamboo potentially has polycarpic reproductive traits rather than monocarpic, and a genet can keep rhizomes and non-flowering patches alive to sustain the organism after mass flowering.

Gregarious bamboo flowering opens a window of opportunity for regeneration in a temperate forest of Patagonia.

Rare gregarious flowering of understorey bamboo species occurs in temperate and subtropical forests around the world, but the ecological consequences of this phenomenon for forest regeneration are not well understood.Field experiments were conducted in an old-growth temperate forest in Patagonia,Argentina after a massive bamboo flowering event, to examine whether light quality and other changes in microhabitats could affect seed germination and growth of overstorey species. Germination of southern beech (Nothofagus obliqua) was positively correlated with red:far red (R:FR) ratios in a range of microhabitats generated by the death of the understorey bamboo (Chusquea culeou). Experimental modification of understorey R:FR ratios to mimic alternative light environments reversed this germination response in plots with senescent understorey, but not in plots with live bamboo. Laboratory incubations demonstrated a significant interaction between R:FR ratios and thermal amplitude in promoting seed germination. Microhabitats also significantly affected the growth of emerged seedlings. Microenvironmental changes generated by this flowering event appear to have opened a window of opportunity for germination and growth of overstorey species.We demonstrate that natural gradients in light quality associated with this ecological phenomenon are a major component affecting forest regeneration in this ecosystem.

Indirect effects of prey swamping: differential seed predation during a bamboo masting event.

Resource pulses often involve extraordinary increases in prey availability that "swamp" consumers and reverberate through indirect interactions affecting other community members. We developed a model that predicts predator-mediated indirect effects induced by an epidemic prey on co-occurring prey types differing in relative profitability/preference and validated our model by examining current-season and delayed effects of a bamboo mass seeding event on seed survival of canopy tree species in mixed Patagonian forests. The model shows that predator foraging behavior, prey profitability, and the scale of prey swamping influence the character and strength of short-term indirect effects on various alternative prey. When in large prey-swamped patches, nonselective predators decrease predation on all prey types. Selective predators, instead, only benefit prey of similar quality to the swamping species, while very low or high preference prey remain unaffected. Negative indirect effects (apparent competition) may override such positive effects (apparent mutualism), especially for highly preferred prey, when prey-swamped patches are small enough to allow predator aggregation and/or predators show a reproductive numerical response to elevated food supply. Seed predation patterns during bamboo (Chusquea culeou) masting were consistent with predicted short-term indirect effects mediated by a selective predator foraging in large prey-swamped patches. Bamboo seeds and similarly-sized Austrocedrus chilensis (ciprés) and Nothofagus obliqua (roble) seeds suffered lower predation in bamboo flowered than nonflowered patches. Predation rates on the small-seeded Nothofagus dombeyi (coihue) and the large-seeded Nothofagus alpina (rauli) were independent of bamboo flowering. Indirect positive effects were transient; three months after bamboo seeding, granivores preyed heavily upon all seed types, irrespective of patch flowering condition. Moreover, one year after bamboo seeding, predation rates on the most preferred seed (rauli) was higher in flowered than in nonflowered patches. Despite rapid predator numerical responses, short-term positive effects can still influence community recruitment dynamics because surviving seeds may find refuge beneath the litter produced by bamboo dieback. Together, our theoretical analysis and experiments indicate that indirect effects experienced by alternative prey during and after prey-swamping episodes need not be universal but can change across a prey quality spectrum, and they critically depend on predator-foraging rules and the spatial scale of swamping.