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1.
We used thermal images of bamboo culms of Guadua angustifolia Kunth to analyze the relationship between culm surface temperature and maturity, driven by the hypothesis that young culms may exhibit lower surface temperatures than old ones. The culm surface temperature shows small but constant differences between three age classes of 1, 2, and 3 years. Our findings indicate that surface temperature may be applied as an additional indicator to support the determination of maturity of guadua culms besides the visual assessment of the culms.  相似文献   

2.
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3.
Epidermal peeling (EPT) and steam-heating (SHT) treatments are two widely processing methods in bamboo industry. Moso bamboo (Phyllostachys pubescens Mazel) and makino bamboo (Phyllostachys makinoi Hayata) are important economical bamboo species in Taiwan and China. The subject of this study was to access the changes of chemical and mechanical properties in moso and makino bamboo culms, which were collected from Taiwan and China after EPT and SHT. As regard to chemical properties, the amounts of extractives and ash were increased both in moso and makino bamboos after EPT and SHT. In contrast, the contains of holocellulose and α-cellulose were decreased after EPT and SHT for two bamboos. Moso bamboo collected from China contained the lowest cellulose content but the highest amount of hemicellulose by SHT. The lignin contents of all samples were no significant different after SHT, and it might due to the structure of lignin did not destroy at 120 °C. For the mechanical properties, the density of all makino and moso bamboo samples was reduced after SHT; moreover, the decreasing trend of density was similar to the reducing of holocellulose, α-cellulose, hemicellulose, and equilibrium moisture content (EMC). All bamboo samples without EPT presented the highest modulus of elasticity (MOE) and modulus of rupture (MOR) whether SHT or not. Both MOE and MOR of all bamboo samples were decreased after SHT. The integrity of the bamboo skin is important for the dimensional stability of the bamboo, and the water absorption ability would be increased after EPT; however, SHT decreased the water absorption of bamboo.  相似文献   

4.
Biochemical changes associated with flowering in Bambusa arundinacea Linn and Bambusa nutans Wall. ex Munro were analyzed. Gregarious flowering was initiated in natural areas and plantations of B. arundinacea in late 2014 and reached full bloom in early 2015, whereas sporadic flowering recorded during 2014–2015 in vegetatively propagated plants of B. nutans. Leaf and nodal shoot samples from flowering culms/shoots and nonflowering culms/shoots were collected in February 2015 at the initiation of fruit filling, then analyzed and compared for soluble sugars, phenols and peroxidase activity. In both species sugars were higher in leaves of flowering culms/shoots and lower in nodal shoots of flowering culms/shoots compared to the nonflowering. Phenols were lower in leaves and nodal shoots of flowering B. arundinacea, but higher in leaves and decreases in nodal shoots of B. nutans. Peroxidase activity increases in leaves and nodal shoots of B. arundinacea after flowering but increases in nodal shoots and decreases in leaves of B. nutans.  相似文献   

5.
Thiamethoxam (ACTARA® 25WG) was evaluated for its insecticidal activities against the bamboo powder post beetle Dinoderus minutus Fabricius (Coleoptera: Bostrichidae). The study showed that thiamethoxam had contact toxicity against D. minutus. Based on dose-mortality responses, LC50 values for thiamethoxam against D. minutus ranged from 1.74 to 7.94 μg ml?1. Laboratory and field exposure tests showed that thiamethoxam at concentration of atleast 10 μg ml?1 may have anti-oviposition or anti-feeding effects on D. minutus and can protect post harvest Bambusa vulgaris Schrad. culms against the infestation of this bamboo boring beetle.  相似文献   

6.
The lignin chemical structures of eight species of the Selaginella family, which are primitive vascular plants, were characterized by alkaline nitrobenzene oxidation, acidolysis, and ozonation. Selaginella involvens, Selaginella tamariscina, and Selaginella remotifolia were collected from the University Forest in Chiba, the University of Tokyo, Japan, and Selaginella biformis, Selaginella pennata, S. involvens, Selaginella chrysorrhizos, and unidentified Selaginella species (Selaginella sp.) were collected from northern Thailand. Lignin of all Selaginella species examined in this study was rich in syringyl nuclei. It was confirmed that a considerable portion of syringyl nuclei of Selaginella lignin formed syringylglycerol-β-aryl ether intermonomer linkages. The major diastereomer of arylglycerol-β-aryl ether intermonomer linkages of Selaginella lignins was the erythro-form exhibiting angiosperm lignin characteristics. In addition, lignins of S. involvens, S. tamariscina, and S. remotifolia collected from the University Forest in Chiba, the University of Tokyo, Japan, were isolated according to Björkman’s procedure, and structural features of the lignins were spectrometrically analyzed. It was confirmed that lignin of Selaginella species, which are primitive pteridophytes, was typical guaiacyl-syringyl type as well as being similar to angiosperm lignin.  相似文献   

7.
Understanding the relationship between tree height (H) and diameter at breast height (D) is vital to forest design, monitoring and biomass estimation. We developed an allometric equation model and tested its applicability for unevenly aged stands of moso bamboo forest at a regional scale. Field data were collected for 21 plots. Based on these data, we identified two strong power relationships: a correlation between the mean bamboo height (H m) and the upper mean H (H u), and a correlation between the mean D (D m) and the upper mean D (D u). Simulation results derived from the allometric equation model were in good agreement with observed culms derived from the field data for the 21 stands, with a root-mean-square error and relative root-mean-square error of 1.40 m and 13.41 %, respectively. These results demonstrate that the allometric equation model had a strong predictive power in the unevenly aged stands at a regional scale. In addition, the estimated average height–diameter (H–D) model for South Anhui Province was used to predict H for the same type of bamboo in Hunan Province based on the measured D, and the results were highly similar. The allometric equation model has multiple uses at the regional scale, including the evaluation of the variation in the H–D relationship among regions. The model describes the average H–D relationship without considering the effects caused by variation in site conditions, tree density and other factors.  相似文献   

8.
The life history and feeding biology of the bamboo powderpost beetle Dinoderus minutus remain poorly understood because the beetles’ oviposition, development, and feeding take place inside bamboo culms. In this study, acoustic emission (AE) monitoring was applied for continuous nondestructive analysis of larval feeding activity and development from the first instar to adult eclosion. Newly hatched larvae were inoculated individually into pieces of madake (Phyllostachys bambusoides) culms. AE hits were recorded using single AE sensors fixed onto the bamboo pieces. Generation of AE hits indicated that larval feeding activity had begun after inoculation. Based on the time course of the hourly AE hit rate, the larvae were feeding constantly during each instar, and feeding activity only ceased during periods of ecdysis and pupation. Half of the individuals examined underwent seven instars and the other half underwent eight instars. The time course of AE hit rate per 5 min exhibited periodic cycles, where continuous meals were separated by inactive phases of ca. 5 min, with an average dominant period of each instar ranging between 0.76 and 2.19 h. After correcting the AE data based on distance attenuation of AE waves, the tendency that AE amplitude increased as the larvae developed through ecdysis events became more apparent. AE monitoring continued after adult eclosion, and the feeding activity of the newly emerged adults continued almost ceaselessly during the Reifungsfrass period.  相似文献   

9.
Delottococcus aberiae De Lotto (Hemiptera: Pseudococcidae) is a new invasive citrus pest in Spain. It causes severe fruit distortions and, as a new invasive mealybug, there is a lack of information about its biology. This research aims to examine the seasonal trend of D. aberiae in citrus, using several sampling methods, as a first step to develop an integrated pest management program. Ten citrus orchards from Eastern Spain were periodically sampled during three years using absolute (plant material) and relative (corrugated cardboard band traps and sticky traps) sampling methods. The three sampling methods showed that D. aberiae completes multiple generations per year, two of them being clearly defined and resulting in high populations. D. aberiae peaked between May and June, damaging the developing fruit. Corrugated cardboard band traps were able to detect prepupa and pupa male instars and gravid females, providing a quantitative measurement of D. aberiae density at its first population peak. The use of corrugated cardboard band traps is recommended to monitor population levels and sticky traps to determine male flight periods, representing simple sampling techniques to monitor D. aberiae. These results will improve the sampling protocols and allow for the development of an integrated pest management program.  相似文献   

10.
The recent introduction of Xylella fastidiosa in Europe and its involvement in the Olive Quick Decline Syndrome (OQDS) in Apulia (Salento, Lecce district, South Italy) led us to investigate the biology and transmission ability of the meadow spittlebug, Philaenus spumarius, which was recently demonstrated to transmit X. fastidiosa to periwinkle plants. Four xylem-sap-feeding insect species were found within and bordering olive orchards across Salento during a survey carried out from October 2013 to December 2014: P. spumarius was the most abundant species on non-olive vegetation in olive orchards as well as on olive foliage and was the only species that consistently tested positive for the presence of X. fastidiosa using real-time PCR. P. spumarius, whose nymphs develop within spittle on weeds during the spring, are likely to move from weeds beneath olive trees to olive canopy during the dry period (May to October 2014). The first X. fastidiosa-infective P. spumarius were collected in May from olive canopy: all the individuals previously collected on weeds tested negative for the bacterium. Experiments demonstrated that P. spumarius transmitted X. fastidiosa from infected to uninfected olive plants. Moreover, P. spumarius acquired X. fastidiosa from several host plant species in the field, with the highest acquisition rate from olive, polygala and acacia. Scanning electron microscopy (SEM) revealed bacterial cells resembling X. fastidiosa in the foreguts of adult P. spumarius. The data presented here are essential to plan an effective IPM strategy and limit further spread of the fastidious bacterium.  相似文献   

11.

Key message

The invasion of moso bamboo ( Phyllostachys edulis (Carriere) J. Houzeau) into neighboring Cryptomeria japonica (L. f.) D. Don plantations significantly altered soil P status and dynamics. This alteration in phosphorus dynamics must be considered when assessing the ecological consequence of moso bamboo invasion in subtropical China.

Context

Moso bamboo is a native species that commonly invades into adjacent forests in Asia. Such invasions may significantly alter soil chemical characteristics because moso bamboo has very different traits compared with the tree species it displaces. However, few studies have investigated the effects of moso bamboo invasion on soil phosphorus (P) dynamics.

Aims

The objective of this study was to investigate the effects of moso bamboo invasion on soil P dynamics. Specifically, we quantified soil total P, available P, acid phosphatase activity (APA), and microbial biomass P (MBP) in moso bamboo-invaded coniferous stands and compared them to uninvaded stands and pure moso bamboo stands.

Methods

We compared seasonal dynamics of soil P (e.g., total P, available P, APA, and MBP) over a 24-month period among three stand types at Lushan mountain in subtropical China: Cryptomeria japonica plantation (CR), Cryptomeria japonica plantation invaded by Phyllostachys edulis (PH-CR), and Phyllostachys edulis stand (PH).

Results

Total soil P concentration was significantly lower in PH-CR than in CR and PH stands, but soil available P concentration was significantly lower in CR and PH stands. Soil APA was significantly higher in PH-CR than in CR and PH stands. Similarly, soil MBP concentration was higher in PH-CR than in CR and PH stands. Also, soil total P, available P, APA, and MBP concentrations displayed seasonal fluctuations in PH-CR, but remained relatively stable in CR and PH stands during the 2 years.

Conclusion

The invasion of moso bamboo into adjacent C. japonica stands significantly increased soil available P, acid phosphatase activity, and microbial biomass phosphorus, but decreased soil total P. The implication of these changes to ecosystem composition, structure, and function must be explicitly considered in managing moso bamboo invasion in subtropical China.
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12.
Natural forest recovery on abandoned farmland is hindered by a variety of factors and active restoration plays an important role when quick afforestation is desired. We investigated seedling survival of four transplanted native tree species (Quercus myrsinifolia, Quercus serrata, Aphananthe aspera, and Rhus sylvestris) by experimentally manipulating the vegetation cover, which was mainly dominated by dwarf bamboo (Pleioblastus chino), and herbivore access to the planting sites on farmland that had been abandoned for 15 years at the start of the study. Few transplanted seedlings of any species survived under intact vegetation cover, irrespective of herbivore presence. In gaps in the vegetation cover, winter browsing by Japanese hare (Lepus brachyurus) damaged all species. However, lower browsing frequency and higher resprouting ability after grazing of the seedlings enabled both Quercus species to survive better than the other species. These results indicate that dwarf bamboo and the hare jointly limit the establishment of native trees in old fields. If active afforestation by transplanting seedlings at sites dominated by dwarf bamboo is planned, a combination of vegetation removal, selection of suitable species, and temporary seedling protection will be most effective.  相似文献   

13.
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14.
In this study, molding moso bamboo strips to a curved shape using hot-press molding operation was explored. Bamboo strips with different thickness and moisture content (MC) were subjected to press molding under 120–210 °C for different time. Changes in the chemical components of bamboo were analyzed by Fourier-transform infrared spectroscopy (FTIR). Effect of MC on thermal mechanical behavior of bamboo was investigated using dynamic mechanical analysis (DMA). Results showed that the influencing degree of four variables on compression and recovery ratios decreased as: temperature?>?time?>?thickness?>?MC. Compression ratio increased and recovery ratio decreased dramatically when pressing temperature exceeded 180 °C. FTIR analysis indicated that polysaccharide (especially hemicelluloses) underwent a progressive thermal degradation during compression at 180 and 210 °C for 40 min, whereas relative content of lignin increased. DMA results showed that bamboo samples with a higher MC had a lower storage modulus value, confirmed water had a plasticizing effect. The loss factor of bamboo with higher MC (12 and 16%) exhibited two major transitions centred around 100 °C (α1) and 50 °C (α2), respectively. The temperature of these α transitions kept almost unchanged as moisture level increased from 12 to 16%. These findings provide fundamental information for the future preparation of curved bamboo as profiled components in engineered products.  相似文献   

15.
Thermoplastic processing of lignin is restricted by its high glass transition temperature (T g). In this study, lignin was modified with polyethylene glycol (PEG) during steam explosion to improve its thermoplastic properties, and the effects of steam explosion and PEG on the chemical structure and thermal properties of lignin were investigated. Structure characterization using Fourier transform infrared spectroscopy showed that hydroxyl and ether functional groups increased and the activity of lignin was improved by steam explosion. In addition, steam explosion treatment was more effective than heat treatment for promoting the reaction of PEG with lignin. Solid-state 13C NMR revealed that PEG was grafted onto lignin. The T g of raw lignin was 164.1 °C; after steam explosion, lignin exhibited more than one T gs. The T g of lignin was reduced when the steam explosion temperature increased and decreased further, to around 60 °C, when PEG was used to modify lignin. Therefore, this work provides an effective approach to reducing the high T g of lignin.  相似文献   

16.
Wood samples of apitong (Dipterocarpus grandiflorua) and ilang-ilang (Ilang-Ilang C. dadloyi) and feces of termites [Cryptotermes brevis (Walker)] fed on these woods were collected from University of the Philippines, Los Baňos. Lignin of each sample was isolated by Björkman’s procedure. There was no significant difference in 1H nuclear magnetic resonance (NMR) spectra or in the methoxyl content between Björkman lignins from original woods and termite feces. Differences were detected in the contents of aliphatic and unconjugated phenolic hydroxyl groups, suggesting minor structural changes of lignin during digestion by termites. In addition, the ratio of syringyl to guaiacyl nuclei of Björkman lignin from termite feces determined by 1H NMR spectra was higher than those from the original woods. The molar ratio of syringyl to guaiacyl nuclei of termite feces was higher than those from the original woods as determined by alkaline nitrobenzene oxidation. These results suggest that the structural changes of lignin in the termite gut are due to the insignificant formation of C-C linkages in guaiacyl nuclei. It was concluded that there were minor changes in the structural features of lignin under mostly anaerobic conditions, in contrast to the significant changes that occur through biological modification under aerobic conditions.  相似文献   

17.
Epidermal peeling treatment (EPT) and steam-heating treatment (SHT) are two popular pretreatments for bamboo processing. This study examined the effects of EPT and SHT on strength properties, profile density distribution, internal bond strength (IB), rate of springback, nail withdrawal resistance, and dimensional stability of oriented bamboo scrimber board (OBSB) made of moso bamboo (Phyllostachys pubescens Mazel) and makino bamboo (P. makinoi Hayata) strips. Results obtained using non-destructive testing (NDT) revealed that EPT for moso bamboo in the processing of OBSB caused lower ultrasonic-wave velocity (Vu) and dynamic modulus of elasticity (DMOEu) parallel to the fiber direction, but higher Vu and DMOEu perpendicular to the fiber direction. However, EPT slightly affected variations in modulus of elasticity (MOE) and modulus of rupture (MOR) of moso bamboo. In contrast, the effects of SHT on Vu and DMOEu were inconsistent and insignificant among the OBSB samples. On the other hands, SHT caused increasing in MOE and MOR of OBSB, but leads to decrease in MOE and MOR of OBSB comprising bamboo strips after EPT. Both EPT and SHT contributed to more uniform profile densities in OBSB and had a positive impact on nail withdrawal resistance. EPT increased IB of moso bamboo and SHT enhanced IB of makino bamboo with epidermis only. Bamboo strips after SHT resulted in significant decrease in water absorption of all OBSB specimens. Reduction in swelling as a result of SHT not only improved the dimensional stability of OBSB but also enhanced strength.  相似文献   

18.
Trochodendron aralioides Sieb. et Zucc. and Chloranthus glaber (Thunb.) Makino [Sarcandra globra (Thunb.) Nakai] belong to primitive angiosperms, and are characterized by the absence of vessels. Ephedra sinica Stapf, which is classified in the gymnosperms, contains vessel elements and fiber together with tracheids. Podocarpus macrophyllus (Thunb. Ex Murray) D. Don var. macrophyllus is reported to give a weak positive Mäule test, although it is classified as a gymnosperm. Podocarpus macrophyllus gave only vanillin on alkaline nitrobenzene oxidation, while E. sinica, T. aralioides, and C. glaber gave both vanillin and syringaldehyde. The molar ratio of syringyl to guaiacyl nuclei (S/V ratio) of C. glaber was significantly low (S/V = 0.08) in comparison with the value for T. aralioides (S/V = 1.56). The erythro form is the predominant diasteromeric form of β-O-4 intermonomer linkages of T. aralioides and E. sinica [molar ratio of erythro to threo forms (E/T ratio): 1.93 and 1.67, respectively]; however, P. macrophyllus and C. glaber lignins, of which S/V ratios were 0 and 0.08, gave approximately equal amounts of erythro and threo forms (E/T ratio: 1.01 and 1.14). Results from 1H NMR spectroscopy agree well with S/V ratios of alkaline nitrobenzene oxidation and E/T ratios of ozonation products. In conclusion differences in guaiacyl lignin and guaiacyl-syringyl lignin do not exactly reflect taxonomical differences, as reported in previous articles. It was found that guaiacyl-syringyl lignin is not necessarily linked to the presence of vessels.  相似文献   

19.
Aromatic spice crops such as coriander, Coriandrum sativum L., and fennel, Foeniculum vulgare L., are among the major seeds exported to the international market. Observations on the stores of these crops revealed differences in their susceptibility to the cigarette beetle, Lasioderma serricorne (F.) (Col., Anobiidae). Coriander seeds proved to be the most appropriate diet for the beetle. The population dynamics of L. serricorne (F.) was determined, showing 3 generations during the period from May to October.  相似文献   

20.
The reaction products of an alkaline treatment of non-phenolic β-O-4-type lignin model compounds (C6–C2-type) consisting of p-hydroxyphenyl (H), guaiacyl (G), and/or syringyl (S) nuclei were identified and quantified. This was performed to examine how the type of H, G, or S nucleus affect the reaction product profiles. The major identified and quantified reaction products were phenol derivatives that were liberated from the aryl sides of the β-O-4 ether bonds of the lignin model compounds. Other products included derivatives of phenylethane-1,2-diol (glycol-type), benzaldehyde, and acetophenone, which originated from the alkyl sides of the β-O-4 ether bonds of the lignin model compounds. Although the type of aromatic nucleus of the aryl side of the β-O-4 ether bond of the lignin model compounds did not significantly affect the profile of the reaction products, the type of the alkyl side nucleus was influential. The glycol-type compound was the exclusive major reaction product when the S nucleus was on the alkyl side of the β-O-4 ether bond. On the other hand, when the H or G nucleus was present, a benzaldehyde derivative was the other major reaction product.  相似文献   

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