Preparation of Rosin-based N-Heterocyclic Carbene Catalyst and Its Catalytic Properties for Addition Reaction of Aryl北大核心CSCD

Two kinds of rosin-based N-heterocyclic carbene (NHC) from dehydroabietylamine and acrypimaric amine were designed and synthesized, and their structures were identified by FT-IR, 1H NMR, 13C NMR, MS and elemental analysis. For screening the catalysts and evaluating their activity, the novel rosin-based NHC molecules were used to catalyze the addition reaction of aromatic aldehydes and aryl boronic acids. The results showed that catalytic activity of the acrypimaric-based NHC(Ap-NHC) was better than that of dehydroabietic-based NHC(Da-NHC), and the optimal catalytic effect was presented at reaction conditions of reaction temperature 60 ℃, the reaction time 4 h, the amount of catalyst 2.5 % and potassium tert-butoxide as alkali, and the yield reached to 95 %. Finally, the influence of different substituent groups on the reactant was studied. When the aryl boronic acid reacted with the aromatic aldehyde with electron withdrawing group, the yield was the highest, while the substituent on the boric acid had little effect on the reaction. © 2018, Editorial Board of «Chemistry and Industry of Forest Products». All right reserved.     

Preparation of liquefied wood-based resins and their application in molding material

To investigate value in use of liquefied wood-based resin applications in molding material, Chinese fir （Cunninghamia lanceolata） and poplar （Populus tomentosa） wood meal were liquefied in phenol. The reactant was co-condensed with formaldehyde to obtain liquefied wood-based resin. For this paper, we investigated the characterization of the resin and its application in molding material. The result shows that the basic properties of liquefied wood-based resin were satisfactory; the bonding strength of plywood prepared with liquefied Chinese fir and liquefied poplar resin can reach 1.54 and 1.00 MPa, respectively. The compression strengths of the molding material prepared with two kinds of liquefied wood resin were 73.01 and 73.58 MPa, almost the same as that of PF resin molding material. The limiting volume swelling of molding material made with liquefied Chinese resin and liquefied poplar resin were 8.5% and 8.3%, thickness swelling rates of water absorption were 3.3% and 4.2%, and the maximum weight ratios of water absorption were 25.9% and 26.2%, respectively. The soil burial test result shows that the weight loss rate of the molding materials made with liquefied Chinese resin and liquefied poplar resin were 8.3% and 9.1% and that of the PF resin molding material was 7.9%. After the soil internment test, the reduction ratio of compression strength of the two kinds of molding material achieved 16.9% and 17.7%, while that of the PF resin molding material was 15.4%. The test results of wood fungi inoculation on the three surfaces of the molding material indicate the breeding rate of molding material prepared with liquefied Chinese resin and liquefied poplar resin were at level 4 and that of PF resin molding material was at level 1 of the ISO standard.     

Osmoregulators in Hymenaea courbaril and Hymenaea stigonocarpa under water stress and rehydration

The objective of this work was to evaluate the effect of different water deficiency and rehydration levels on the concentrations of osmoregulators in two plant species(Hymenaea courbaril and H. Stigonocarpa) in the Amazon. We adopted a 2×5×5 factorial system,referring to 2 species(H. courbaril and H. stigonocarpa)and 5 stages of hydration and rehydration. The five hydration and rehydration stages were established in:(1)Control treatment E0;(2) Plants with 13 days of stress after incubation—E13;(3) Plants with 26 days of stress E26;(4)The plants that were established after 26 days after incubation and rehydrated for two days(RD2);(5) rehydrated for two days(RD4). The plants that were established after 26 days after incubation and rehydrated for four days. The experiment totaled fifty young plants with five replicates.Biochemical measurements were performed at the beginning of the experiment(E0) at 13(E13) and 26(E26) days after the water stress, in which the plants were rehydrated,repeating the analyses after two(RD2) and four(RD4)days. Both species increased the sucrose concentration by18%, with a decrease of 52% in starch content. The RD4 time presented the highest mean starch concentration(0.19 mmol g-1 of the residue for H. courbaril and0.27 mmol g~(-1) of residue for H. stigonocarpa). Increased proline concentrations were recorded for controls until RD2 for both species. For glycine betaine, the highest increases in treatments E26 and RD2 were observed for the H. courbaril species. Our rehydration period was not sufficient for total recovery of pre-stress concentrations of all studied solutes.     

A comparison of Guibourtia copallifera Benn. stands in South West Burkina Faso-community structure and regeneration

Shifting agriculture, fire, and over exploitation of wood and copal resin are the major causes of Guibourtia copallifera Benn. vulnerability in the south-west of Burkina Faso. Conservation of endangered species requires a thorough understanding of the dynamics of small populations. In the present study, we investigated the diversity and the dynamics of G. copallifera communities in two different types of land use history, a protected area (stated forest of Comoé-Leraba) and an unprotected area (the woodlands of Tourni and Timba). A total of 17 rectangular plots (50 m × 20 m) were sampled in both protected and unprotected areas. All woody species were systematically identified, measured and classified into diameter and height classes. In the two different types of land use, the dynamics of G. copallifera’s communities were good, and the diversities were similar and low with high β diversity.     

Plant communities and reproductive phenology in mountainous regions of northern Libya

Within the semi-desert landscape of northern Libya, two sub-humid escarpments occur: Al-Akhdar in the east and Nafusa(Jabal Al-Gharbi) in the west. This study compares plant communities in the two regions, which are along an elevation gradient, in terms of species composition and diversity, frequency of different Raunkiaer life forms, and reproductive phenology. The two regions differed in species composition and life-form frequency between regions and between elevation zones within each region. Patterns were associated with the lower rainfall and lower moisture-holding capacity of soils at Nafusa,resulting in more xeric conditions. Only 13% of species were shared between the two regional landscapes. Species diversity, life-form frequency, and duration of the flowering–fruiting phenophase were all affected by elevation above sea level. The duration of flowering and fruiting in spring and fall was associated with environmental conditions, although there were different thresholds in the two regions. There was both a spring and fall episode of flowering at Nafusa, but only spring flowering at Al-Akhdar. It is anticipated that there will be a gradual shift of plant communities to higher elevations and loss of certain sensitive species in response to ongoing climate change.     

Activities of some defense proteins associated with age or plant family in larch needles of Larix olgensis and L. kaempferi × L. gmelinii

Defence proteins are a kind of chemical defence compounds. They play a key role in plant restraining biotic and abiotic harm. To illuminate activities of some defense proteins associated with age or plant family of larch, the larch needles were collected from two different families of Korean larch, Larix olgensis and a hybrid larch, L.kaempferi × L. gmelinii, respectively, and then the activities of defence proteins in those were tested using a UV spectrophotometry. The results showed that the activities of protective enzymes at the16-/17- and 19-year-age groups were higher than those at the other age groups in the both larch species. While the activities of polyphenol oxidase(PPO) at the 16-/17-year-age group and phenylalanine ammonia-lyase(PAL) and protease inhibitors at the 19-year-age group were the highest among all age groups.Then, compared with L. olgensis, the hybrid larch had significant effects on the activities of protective enzymes.The effects of plant family on the activities of PAL and chymotrypsin inhibitor were significantly different, and then those on the activities of PPO were not significantly different. The effects of the two families in L. olgensis on the activities of trypsin inhibitor(TI) were significantlydifferent, while those in the hybrid larch on the activities of TI were contrary. To conclusions showed that the different age and plant family significantly affected the activities of defence proteins in the needles of two larch species, and then enhanced the larch resistance to pests. These could play a key function in forestry tree genetic improvement and management in future.     

A floristic survey of the Hyrcanian forests in Northern Iran,using two lowland-mountain transects

We investigated the floristic composition of the Hyrcanian forests and the related forest-steppe ecotone in Northern Iran by using two long ecological transects, from lowland to upper mountain areas. The study was conducted during 2008 and 2009 and yielded the identification of 395 plant taxa belonging to 233 genera and 78 families. Dicots with 300 taxa were the richest groups of the flora, followed by monocots with 75 taxa, pteridophytes with 18 species,and gymnosperms with two species. The largest families were Asteraceae(33 taxa); Rosaceae(32 taxa); and Poaceae(30 taxa), and the most diverse genera included Carex(15 taxa); Alchemilla(7 taxa); and Poa, Geranium and Acer(6 taxa each). Hemicryptophytes were the most dominant life forms in the area(40 %); followed by geophytes(31.4 %); phanerophytes(15.4 %); therophytes(11.4 %); and chamaephytes(1.8 %). Phytogeographically,Euro-Siberian/Irano-Turanian elements(86 taxa, 21.8 %)and Euro-Siberian elements(85 taxa, 21.5 %) were the most common chorotypes in the area. Out of 395 taxa, 66taxa(16.7 %) were endemics and subendemics in Iran, of which 26 taxa were exclusively endemics of Iran.According to the IUCN Red List Categories, 48 threatened plant taxa were found in the study area. Plant diversity, life form, and chorotypes in the current study were compared with similar transect studies in other areas of the Hyrcanian forests and in different altitudinal belts, using S?renson similarity indices. Floristic composition of the surveyed transects demonstrated almost 50 % similarity between them.     

An improved draft genome sequence of hybrid Populus alba×Populus glandulosa

Populus alba × P.glandulosa clone 84 K,derived from South Korea,is widely cultivated in China and used as a model in the molecular research of woody plants because of hi gh gene transformation efficiency.Here,we combined63-fold coverage Illumina short reads and 126-fold coverage PacBio long reads to assemble the genome.Due to the hi gh heterozygosity level at 2.1% estimated by k-mer analysis,we exploited TrioCanu for genome assembly.The PacBio clean subreads of P.alba × P.glandulosa were separated into two parts according to the similarities,compared with the parental genomes of P.alba and P.glandulosa.The two parts of the subreads were assembled to two sets of subgenomes comprising subgenome A(405.31 Mb,from P.alba)and subgenome G(376.05 Mb,from P.glandulosa) with the contig N50 size of 5.43 Mb and 2.15 Mb,respectively.A high-quality P.alba × P.glandulosa genome assembly was obtained.The genome size was 781.36 Mb with the contig N50 size of 3.66 Mb and the longest contig was 19.47 Mb.In addition,a total of 176.95 Mb(43.7%),152.37 Mb(40.5%)of repetitive elements were identified and a total of 38,701 and 38,449 protein-coding genes were predicted in subgenomes A and G,respectively.For functional annotation,96.98% of subgenome A and 96.96% of subgenome G genes were annotated with public databases.This de novo assembled genome will facilitate systematic and comprehensive study,such as multi-omics analysis,in the model tree P.alba X P.glandulosa.     

Wettability changes of wheat straw treated with chemicals and enzymes

A study was conducted to test wettability changes of the wheat straw treated with different methods for the preparation of wheat straw particle board. The wheat straws were separately sprayed with two chemicals (0.6% NaOH, 0.3% H2O2) and three enzymes (lipase, xylanase, cellulase). The contact angle between water and the surface of wheat straw was measured and the spreading-penetration parameters (K-values) were also calculated with wetting model. The surfaces of treated wheat straw and control sample were scanned by means of Micro-FTIR, and their peaks arrangements were analyzed. The surface morphologies of treated wheat straw and control sample were also observed by SEM. Chemical etching was found on the exterior surfaces of the straws treated separately with 0.6% NaOH and 0.3% H2O2; furthermore, the spreading-penetration parameters (K-values) of the distilled water on the exterior surfaces of the treated wheat straw along the grain were higher than that of control. The wettability of exterior surfaces of the wheat straws treated separately with lipase, xylanase and cellulose were improved after treating for seven days, and among the three enzymes treatments, the lipase treatment showed best result. The lipase treatment and NaOH treatment were determined as better methods for improving the wettability of wheat straw surfaces. However, in the economic aspect, NaOH treatment was more practical and easier in the pretreatment for the manufacture of straw particle board.     

Decomposition and nutrient release patterns of Phyllostachys bambusoides and Arundinaria racemosa, India

We investigated decomposition and nutrient release patterns of leaf and sheath litter of two important highland bamboo species (viz. Phyllostachys bambusoides Sieb. (Zucc.) and Arundinaria racemosa Munro) by using a litter bag technique. Our objective was to improve understanding of the addition of organic matter and nutrients to soil from the litter of two abundant highland bamboo species, species that support the local population of the region in many ways. N concentration and N/P ratio were significantly higher (p<0.01) in leaf litter of P. bambusoides. Significantly, larger values of lignin concentration, C/N ratio, and lignin/N ratio were found in the sheath litter of A racemosa. Weight loss of both leaf and sheath litter was strongly positively correlated with N and N/P ratio, and significantly negatively correlated (p<0.01) with C/N ratio. Lignin/N had a negative correlation with decay rate. In both species, only lignin concentration of the litter showed strong positive correlation with N release. Litter decomposition and N release patterns were similar for the two bamboo species, whereas, P release rate from leaf litter was higher in P. bambusoides and differed significantly between sheath and leaf litter for both species. The complex pattern of nutrient release through mineralization and immobilization during litter decomposition ensures nutrient availability in both managed and natural bamboo stands subjected to anthropogenic disturbances.     

Cloning and sequence analysis of nine novel MYB genes in Taxodiaceae plants

Myeloblastosis(MYB) is one of the largest transcribed factor families in plants. To gain an overall picture of the evolution of MYB genes in relict plants, we cloned nine novel MYB genes in Taxodiaceae plants(Taxodium distichum, Taxodium ascendens, Cryptomeria japonica var. Sinensis, Cryptomeria japonica cv. Araucarioides, Cryptomer Japonica, Metasequoia glyptostroboides, Cunninghamia lanceolata, Taiwania cryptomerioides and Glyptostrobus pensilis). The deduced amino acid sequences for MYBs showed that the nine MYB proteins contained two DNA binding domains. The first domain is from amino acid position 29 to 78, wherein three tryptophanes at 33, 53 and 73 were separated by 19 amino acids, respectively. The second domain is from amino acid position 82 to 127, wherein three tryptophanes at 86, 105 and 124 were separated by 18 amino acids, respectively, whereas the first tryptophane at amino acid position 86 is replaced by a phenylalanine. The characterization of these conserved domains at nine MYBs indicated that they all belong to the R2R3-MYB group. The secondary structure analysis showed that α-helix and β-turn are the major motifs of the predicted secondary structure of MYBs. The three dimensional model of each MYB protein showed that the structure is like clip, making it more flexible and mobile. The similarities between the nine MYB proteins in Taxodiaceae were calculated. The highest identical value of 99% is between CjsMYB, CjMYB and CjaMYB, whereas the lowest value of 82% is between TaMYB and ClMYB. According to the phylogenetic tree, the distances between different genera were relatively large whereas those within genera were relatively small. As expected, accessions of the same genus formed a subgroup before being grouped with other genera.     

Effort on planting and product development of <Emphasis Type="Italic">Azadirachta indica</Emphasis> in Southwest China

Twenty-four provenances of two species （Azadirachta siamensis and Azadirachta indica） have been introduced to China from South Asia, Southeast Asia and Africa Since 1995. This paper summarizes the researches on the introduction and planting of Azadirachta indica and analyzes the morphological, phenological characteristics, the growth rhythm, pollinating and seed yielding features of the intro- duced 24 provenances of the two species as well as the variations of filial generation plants. The experiments showed that most of the prove- nances of,4. indica have normal growth and can blossom and fruit in the dry-hot valleys with tropical climate conditions in Yunnan Province, China. The normal regions for A. indica were classified and the selection criteria for superior plants were put forward in this paper, more- over, the major contents of industry planning and technical approaches for A. indica plantation establishment were discussed and the countermeasures to reduce the neem-based pesticide products were also proposed.     

Implications of crude oil pollution on natural regeneration of plant species in an oil-producing community in the Niger Delta Region of Nigeria

The study evaluated the impact of crude oil pollution on natural regeneration of plant species in a major oil-producing community in the Niger Delta region of Nigeria. Three sites—unpolluted site(US), polluted and untreated site(PUS), and polluted and treated site(PTS)—were purposively chosen for the study. The seedling emergence method was used to evaluate soil seed banks in the various sites at two depths, 0 to 10 cm and 10 to 20 cm. Woody-plant species richness, abundance, and diversity were higher in the US seed bank than in the PUS and PTS seed banks. The highest number of non-woody plants was observed in the US, followed by the PTS, and then the PUS. Both species richness and diversity of non-woody plants were highest at the US, followed by the PUS, and lowest in the PTS. Woody species in the US seed bank were 87.5% and 80% dissimilar with those of the PUS and PTS at 0–10 cm and 10–20 cm respectively. No variation was observed between woody species in the PUS and PTS seed banks. Non-woody species at 0-10 cm US seed bank were 73.08% dissimilar with those of PUS at the two soil depths and 81.48/88.46% dissimilar with those of the 0–10/10–20 cm of the PTS respectively. At 10–20 cm, non-woody species of the US were 69.66% dissimilar with those from each of the two soil depths in PUS; and 73.91/81.82% dissimilar with those of 0–10/10–20 cm of the PTS respectively. Non-woody species variation between the PUS and PTS was higher at 10–20 cm than 0–10 cm. The poor seed bank attributes at the polluted sites demonstrates that crude oil pollution negatively affected the natural regeneration potential of the native flora because soil seed banks serve as the building blocks for plant succession. Thorough remediation and enrichment planting are recommended to support the recovery process of vegetation in the polluted areas.     

Logging and topographic effects on tree community structure and habitat associations in a tropical upland evergreen forest,Ghana

We determined the response of tree community structure to logging disturbance and topography,and the patterns of tree-habitat associations in Tano Offin Forest Reserve,Ghana.We sampled trees in 27 20 m× 20 m plots randomly and equally distributed in three topographic habitats(slope,valley,and hilltop) in each of two forests:logged and unlogged.Two topographic features,altitude and degree of slope,were measured and related with species composition.Overall,there were significant effects of logging and topographic habitat and their interaction on species diversity and composition,with the unlogged forest and valley habitat supporting higher diversity.Tree diversity varied among the topographic habitats in the logged but not in the unlogged forest.There were topographic effects on abundance of individual species but not on tree community abundance and basal area.Logging and its interaction with topographic habitat showed significant effects on tree abundance and basal area.Some species were associated with specific topographic habitats or a combination in the logged and unlogged forests.However,the patterns of habitat associations of the species differed between the logged and unlogged forests.     

Differences in arthropod communities between island and inland Masson pine forests infested by pine wilt disease in Zhejiang Province

The invasion of Bursaphelenchus xylophilus （pine wood nematode, PWN） carried by Monochamus alternatus predominately attacks Masson pine （Pinus massoniana） forests and causes great economic losses in China. In this study, we assessed whether the effect of the invasion of PWN is different between island and inland forests. Arthropods were sampled in Fuyang （inland） and Zhoushan （island） counties in Zhejiang Province with sweep netting and light traps at four plots. During two field periods （May to June 2004 and September to October 2005） a total of 21,916 insects, representing 384 species belonging to 99 families and 15 orders, were collected in the sample plots from the island, whereas, from the inland forest a total of 29,262 insects, representing 308 species belonging to 96 families and 13 orders, were found. A hierarchical cluster analysis （HCA） and one-way ANOVA, based on the composition of different arthropod guilds, were performed. The results showed that there was no significant difference in the composition of arthropod communities at the family level between inland and island. But these two habitats had a significant effect on the composition of species, individuals, sub-communities and energy class levels. Statistically, the composition of the two orders, Lepidoptera and Diptera, in the two habitats were significantly different.     

Morphology and leaf nutrition of introduced Robinia pseudoacacia clones

In order to study and popularize clones from the introduced Robinia pseudoacacia, morphological charac- teristics and leaf nutrition of samples of a three-year-old stand were observed and analyzed during its growing season. Combined with data on rooting ability, height and basal diameter, comparisons were made on morphological characteristics, growth traits and leaf nutrition of 11 introduced R. pseudoacacia clones (two from Hungary and nine from South Korea) and two domestic clones. The results show that there are significant differences in growth and morphological characteristics among the 13 clones, but no significant differences in the contents of crude protein and crude fibers in the leaves (p > 0.05). Height and basal diameter growth of clones B and G were recorded as the fastest, while clone H1 was the slowest. Clone H2 had the largest leaflets, three times as large as other clones, while K4 had the heaviest dry weight per 100 leaflets because of its thick leaves. The 13 clones can be divided into four classes based on the number of leaflets per compound leaf, i.e., 1-3, 13-17, 15-23 and 21-25. There were significant differences in thorn size: H2 , with the largest leaflets had the smallest thorns. While of course all clones produced roots, there were significant differences; clones 2N, K5 and B had many adventitious roots, while clones K3 , K4 and H1 had few. Correlation between content of crude protein and (length × width of leaf) was positive (p < 0.05), while correlations of the content of crude protein, with the number of leaflets per compound leaf, petiole length of compound leaf and thorn length were negative (p < 0.01). Plant height and basal diameter were positively correlated with each other (p < 0.01) and negatively correlated with base width of thorns (p < 0.05) .     

Interspecific hybridization between Bursaphelenchus xylophilus and Bursaphelenchus mucronatus

Bursaphelenchus xylophilus is the pathogen that causes pine wilt disease, which has greatly damaged forests and ecosystems in countries of East Asia and Europe.Bursaphelenchus mucronatus is closely related to B. xylophilus in morphology and host plant specificity. A longrunning debate has existed regarding whether these two species can successfully produce hybrid offspring. In the present study, we performed in the laboratory, hybridization of two B. xylophilus nematode isolates from China and Japan and three B. mucronatus isolates from China, Japan and France. Nematode isolates of B. xylophilus were successfully crossed with B. mucronatus isolates, and the rate of hybridization was relatively high; however, some hybrid offspring died. Successful hybridization occurred between B. xylophilus and B. mucronatus isolates from China, and 22 generations of hybrids were produced. All F1 hybrids could be backcrossed with their parents and produce offspring. Variation in mucro length among the hybrid offspring and their parents was observed. The hybrid offspring and their parents were inoculated into 3-months-old black pine(Pinus tunbergii) seedlings. Weaker pathogenicity of hybrid offspring was observed compared with that of their parents, and significantly fewer offspring nematodes than parents were reisolated from pines. Therefore, the offspring of B. xylophilus and B. mucronatus may exist in the forest and could influence disease epidemics.     

Comparison on Estimation of Wood Biomass Using Forest Inventory Data

Based on sixth and seventh national forestry inventory data of the six provinces,including Guangdong,Jiangxi,Guizhou,Shaanxi,Jilin and Beijing,the three methods(IPCC,continuous function for biomass expansion factor and weighted biomass regression model) were selected to estimate wood biomass in this paper.The estimation of the three methods were compared and analyzed from calculating process,method characters,repeatability and verifiability to stability of growth rate of biomass between two periods.The results showed the total biomass estimated by IPCC method with variable BEF2 was large,the total biomass estimated by IPCC method with constant BEF2 was small and the total biomasses estimated by continuous function for biomass expansion factor and weighted biomass regression model were middle.The biomass expansion factor derived from weighted regression model was most stable in the different provinces. Based on the seventh national forestry inventory data, the biomass expansion factors of various kinds of tree species derived from IPCC and the weighted regression model were more stable than the biomass expansion factors derived from continuous function method.The growth rate of biomass between two periods was the same regular pattern as the biomass expansion factors.