Development of cork oak (Quercus suber L.) seedlings in response to tree shelters and mulching in northwestern Tunisia

The need for reforestation in cork oak （Quercus suber L.） areas is challenged by difficulties. Principal among these is herbivory of young plants, vegetative competition, and slow growth rates of cork oak seedlings. We evaluated the early development of cork oak seedlings treated using tree shelters and mulching in northwestern Tunisia. We tested three tree shelter treatments （non-vented, vented, and control） to shield seedlings from animal damage and five mulch types to control competing vegetation （Italian Stone Pine, Lentisk, combination of Italian Stone Pine and Lentisk （organic mulches）, gravel （inorganic mulch） and no mulch）. At the end of the two-year experiment, sheltered seedlings were 89-99% taller than unshelteredseedlings and had higher numbers and lengths of shoot growth flushes. In contrast, both stem diameter growth and dry weight biomass （from samples extracted after two years） were significantly reduced inside tree shelters. Root-to-shoot ratio was not significantly different in sheltered vs. unsheltered seedlings, suggesting that tree shelters do not adversely affect this parameter. Mulching alone did not favour growth, but could be beneficial when combined with tree shelters. The combination of vented tree shelters and gravel mulch was the most effective treatment for promoting diameter, height and stem volume growth.

Macronutrients Effect on Secondary Somatic Embryogenesis of Moroccan Cork Oak (<i>Quercus suber</i>L.)

To define the preliminary embryogenesis culture conditions of Moroccan Cork Oak (Quercus suber L.) in secondary propagation systems, secondary embryos formation from primary embryos were analyzed using seven macronutrient medias: (Chalupa) (BTM), Murashige and Skoog (MS), Schenk and Hildebrant (SH), Schenk and Hildebrant with half content macronutrients (SH ?), full Gamborg (G), Margara (N30K) and Woody Plant Media(WPM). Mature primary embryos at cotyledonal stage of 8 - 10 mm, were placed in each culture medium, and supplemented with 30 g/l of glucose and 7 g/l of agar without PGR. The experimental design consisted of a Petri dish containing three embryos explants. Each one of the seven treatments was composed of ten Petri dishes. Mean number of secondary somatic embryos, clusters and new embryogenic formation on clusters were recorded after 8 weeks, and evaluated by statistical analysis. There were no significant differences (p ≤ 0.05) in clusters and new embryos on clusters formation among evaluated media;but mean number of secondary embryos was significantly higher in N30K (4.37 ± 0.48) compared with control media (1.37 ± 0.15). The morphology of secondary embryos grown in the N30K medium exclusively showed the presence of three embryogenic stages: early cotyledonal with translucide aspect, white opaque, or green, and mature embryos. These results indicate that the medium do influence the morphogenic characteristics of produced embryos. Our finding revealed that secondary somatic embryos produced in N30K medium presented better morphogenic potential, with different stages of embryogenic formation.

Effect of Amino Acids on Secondary Somatic Embryogenesis of Moroccan Cork Oak (<i>Quercus suber</i>L.) Tree

In the present study, we tested the effect of amino acids on secondary somatic embryogenesis of Moroccan cork oak (Quercus suber L.). Secondary mature and immature somatic embryos were obtained from primary somatic embryos cultured in N30K medium supplemented with nineteen amino acids. Stimulation of embryogenesis was dependent on the type and concentration of amino acid in the medium. Thus, L-glutamine and L-asparagine at 3.42 mM have been proved to be the most favorable for the formation of functional somatic embryos and the induction of secondary somatic embryos.

Evaluation of Phenotypic Diversity by Use of Variable Analysis Multi of Various Populations of Oak Cork (<i>Quercus suber</i>L.) in Tunisia

Populations of oak cork (Quercus suber L.) originated from different areas in Tunisia were analysed based on morphological characters to assess the overall degree of phenotypic variability, to detect similarities between the genotypes and to evaluate significant forest features. One-way ANOVA analysis shows a significant difference between oak cork populations and demonstrates that parameters measured on leaves show an important degree of variability and permit to discriminate oak cork individuals. Vegetative variables are leaf length, leaf width, petioles length, number of leaf veins, petioles width, spines number, leaf area, length nipples, diameter nipples, weight nipples, and height trees. Diameter trees were scored and subjected to multivariate analysis. Results showed a considerable diversity among local germoplasme of oak cork. Principal component analysis (PCA) revealed that the characters related to the length and width of the sheets and the nipples accounted for a large proportion of the observed variability. Cluster analysis showed a typically continuous phenotypic diversity among oak cork accessions, and little asso-ciations between accessions from same geographic origin. Also, some heterogeneity within accessions that received the same denomination was evidenced. The variability observed between different populations is attached to phenotypic characters which depend primarily on two factors, gene and environment.

Callogenesis of Cork Oak(Quercus suber L.)through In Vitro Culture of Nodes and Internodes

The present study is about in vitro culture of cork oak, through callogenesis from nodes and internodes, withdrawn from seedlings of three months. These latter were obtained after acorns germination on peat. Nodes showed a high capacity for callogenesis and the best rate was obtained on a medium containing Woody Plant Medium (WPM) macronutrients, Murashige and Skoog (MS) micronutrients and vitamins, 4.5 μM of 6-Benzylaminopurine (BAP), 7 μM of 2-naphthalineacetic acid (NAA) and 30 g/L of Sucrose. Calluses are transplanted onto the same mineral solution, with or without growth regulators, and in the 3rd transplanting;small white embryos appear on the surface of calluses.

Influence of Amino Acids on the Secondary Somatic Embryogenesis Proliferation Process of Moroccan Cork Oak (<i>Quercus suber</i>L.)

The present study aims to explore the regeneration potential of Moroccan cork oak through the secondary somatic embryogenesis process. Particularly, we focus on the analysis of amino acids influence on the quantity and quality of the regenerated secondary embryos. The amino acids tested are: Glutamine, asparagine, arginine, tryptophane, methionine, casein hydrolysate and urea. Each amino acid is added in the Margara (N30K) medium at different concentrations ranged between 10 and 500 mg/l. The results are collected after 2 months of culture. First analysis shows that the glutamine and the casein hydrolysate gives a maximum number of somatic embryos, clusters and pre-embryos newly formed on the clusters. By comparison to the control medium, the increase of the secondary embryos number directly formed exceed 36% in the case of casein hydrolysate and 35% of in the case of glutamine both at the concentration of 30 mg/l. However, the test of the combination of these amino acids did not have any significant results. In terms of quality, the influence of amino acids on the morphology of secondary embryos was analyzed.

欧洲栓皮栎软木构造与物理性质研究进展

介绍了国内外学者对欧洲栓皮栎软木宏观、微观构造的研究现状。欧洲栓皮栎软木细胞为14面体,弦切面细胞呈蜂窝状排列,横切面和径切面呈砖墙状排列;细胞壁上存在褶皱。欧洲栓皮栎软木具有密度低、弹性好、热绝缘性好、吸声减震和防水等优良物理性能。

高山栎叶的形态结构及其与生态环境的关系

对分布在不同生态环境条件下的硬叶常绿阔叶林建群种高山栎组植物叶的形态解剖特征进行了比较研究。结果表明，高山栎组植物叶的形态结构兼有非肉质旱生植物和高山植物的性状，这是它们对生态环境广泛适应的基础。每一个种除气孔器类型及腹面二层表皮细胞性状比较稳定外，其他性状，如气孔的大小和密度、表皮细胞的形状，垂周壁的类型、叶片的厚度、角质膜的厚度均受环境条件修饰，不是稳定性状，不具分类学意义。对同一个种的不同生活型，如乔木、小乔木和灌木，在解剖结构上没有明显的区别特征。地中海的冬青栎（Ｑｕｅｒｃｕｓｉｌｅｘ）的表皮特征和高山栎组植物有很大的相似性。

试用多元分析方法研究植物形态结构与生态环境的关系

应用多元分析方法对栎属高山栎组不同环境条件下的３３个植物样品的形态解剖性状的１７个指标进行了综合分析．结果表明，二元指示种分析（ＴＷＩＮＳＰＡＮ）聚类的结果能很好地把相似生态环境条件下的样品聚在一起，对样品进行无趋势对应分析（ＤＣＡ）和主成分分析（ＰＣＡ）都得到了满意结果．植物形态解剖性状的聚类、排序分析也可用来研究个体性状之间变异的连续性和间断性，进而有助于分类学的研究．

新型软木原料栓皮槠的采剥、再生试验及理化性能研究

对栓皮槠与栓皮烁树初再生皮在采剥难易、含皮量、再生速度、再生率及其栓皮在外观、质量、化学组成的差异及地理差异等方面进行的对照试验结果表明：栓皮槠栓皮质量好，再生能力强，产皮厚，剥皮工效高，经济效益好，是优良栓皮树种，可用来改造我国的栓皮烁林。

栓皮槠软木性质及应用研究进展

软木作为可再生资源,独特的性质使其应用区别于木材。本文概述栓皮槠软木基础性质,从软木形成过程、显微结构、超微结构介绍软木及其微观构造;分析软木细胞壁中主要化学组分—木栓脂、木质素和多糖;评述软木力学研究现状及需要解决的问题;同时从软木直接利用和软木复合材料概述其在实际中的应用。目前我国软木研究还处于起始阶段,通过分析栓皮槠软木现状,讨论其中存在问题,以期为我国软木深入研究与高附加值利用提供借鉴。

Growth phenology adjusts to seasonal changes in water availability in coexisting evergreen and deciduous mediterranean oaks

Different leaf(evergreen vs.deciduous habit)and xylem(diffuse-vs.ring-porous wood)traits represent contrasting strategies to face seasonal changes in water availability and temperature.However,how contrasting leaf and xylem habits of coexisting tree species affect stem wood formation and tree-ring development remains poorly understood.Here,we investigated the spatio-temporal patterns of wood formation in two deciduous oaks(Quercus faginea and Quercus petraea)and two evergreen oaks(Quercus ilex and Quercus suber)coexisting in seasonally dry Mediterranean forests along an aridity gradient in Spain.We hypothesized that growth responses to drought and intra-and inter-annual growth patterns would differ between functional groups.We simulated intra-and interannual growth using a modified version of the Vaganov-Shashkin(VS)process-based,growth model.The VS model simulations were used to estimate growth changes under a high emission scenario(RCP 8.5)for the current distribution of the study oak species and to forecast their future performance under warm(4.8℃)conditions in the Iberian Peninsula.Our simulations indicate that climate warming would induce a shortening of the ringgrowth season and a reduction of radial growth in evergreen and deciduous Mediterranean oaks,particularly in dry sites from southern and eastern Iberia currently occupied by Q.ilex and Q.faginea.Evergreen oaks may better recover after dry periods than deciduous oaks by resuming growth after the summer drought.Low soil water availability in spring would be more detrimental to growth of deciduous oaks.Process-based growth models should be refined and validated to better forecast changes in tree growth as a function of climate.

Climate-driven variations in productivity reveal adaptive strategies in Iberian cork oak agroforestry systems

Background:Cork oak agroforestry systems(AFS)have been managed for centuries by humans to produce cork and other goods and services and have recently been recognised as an important reservoir for biodiversity improvement and conservation.However,despite having recently been included as a natural habitat of community-wide interest within the EU Habitats Directive,these systems are in a critical situation of decline.Among other factors,they are strongly threatened by climate change,the effects of which are also expected to be particularly severe in the Mediterranean region.In this study,we aimed to evaluate the influence of climate variability by examining primary production indicators and also to analyse whether the geographical location may have a role in the incidence of the adverse effects of climate.Methods:Cork oak AFS were identified in the Forest Map of Spain and the Land use map of Portugal and categorized on the basis of canopy cover.Seasonal climate data from 2001 to 2020 were used to model relationships with climate predictors and proximity to the coast.Hotspot analysis was conducted to identify significant spatial clusters of high-and low-efficiency areas.Results:The responses to the influence of climatic conditions differed among the various cork oak AFS categories,particularly in the forest category,which was less dependent on climate variations.Relative humidity and water availability were the main drivers of net primary production(NPP).Carbon use efficiency(CUE)was limited by relative humidity and spring temperature in open ecosystems.Proximity to the coast proved beneficial,especially in years with adverse weather conditions,but was not a limiting factor for survival of the ecosystem.Finally,the results of the hotspot analysis supported the other findings,highlighting high-efficiency areas close to the coast and cold spots grouped in specific areas or dispersed inland.Conclusions:Canopy plays a key role in the influence of climatic conditions,particularly in forest categories in which a high density seems to generate microclimate conditions.Water availability,both via the soil and air moisture,is the main driver of primary production,reflecting different adaptive strategies.The oceanic atmosphere may act as a buffer in years of extreme drought.

Vegetation Dynamism in the Mixed Conifer/Broadleaves Species Artificial Stands Crossed by Fire： The Arci Mountain Case Study in Sardinia

Immediate cutting and logging of mixed conifer/broadleaves species in a man-made forest crossed by fire in 2009 in the Arci Mountain in Sardinia can not guarantee as the best post-fire regeneration. The study case reports the differences in the density and in the height of seedlings. The release of damaged Pinus halepensis Mill. stems seems to confirm the tree seeder role of this species.

四种栎树EST-SSR信息分析

为开发栎属遗传多样性检测的SSR标记,分析了蒙古栎、无梗花栎、夏栎和欧洲栓皮栎EST-SSR的特点,结果表明蒙古栎的EST中3 209.46 bp有一个SSR,无梗花栎中每6 160.36 bp有一个SSR、夏栎中每5 883.30 bp有一个SSR,欧洲栓皮栎中每6 129.12 bp有一个SSR。蒙古栎、无梗花栎、夏栎和欧洲栓皮栎EST-SSR的平均长度分别为21.65 bp、21.1 bp、20.66 bp和20.65 bp。四种栎类中不同基元的EST-SSR的分布频率具有非常一致的特征,均是二基元、三基元和六基元的SSR分布频率最高,达20%以上。而四基元和五基元的SSR在四个种类中的分布不到0.05%。二基元的SSR中大于1%的SSR均是AG、CT、TC、GA、AT、TA基元,并且在蒙古栎、无梗花栎和夏栎中AG、CT、TC基元的分布频率最高,而在欧洲栓皮栎中是TC、GA、AG的分布频率最高;三基元的SSR中,含CAA、GAA、TCT、CTT的SSR在四种栎类中都存在。六基元的SSR中大于1%在四种栎类中出现的类型均较少,为0～4种。

国内外软木研发进展与我国对策

软木是以栓皮栎的栓皮为原料,具有弹性、保温隔热、防滑耐磨、消音减震、安全无毒等特性的一种可再生绿色材料,产品广泛用于国计民生等重要行业和领域。文中介绍了世界软木资源分布情况、软木用途和产业趋势,综述了国内外软木细胞结构、化学成分、工艺与产品研发等概况,在比较欧美各国与我国软木产品标准制定/修订现状的基础上,概述了我国对现行软木纸标准LY/T 1320-2010和软木纸试验方法LY/T 1321-2013的修订研究过程。提出了加强我国软木研发的建议,即紧跟软木脂研究国际前沿,加大软木脂基础与应用技术研究;加强软木行业标准建设,实现软木产品标准国际化、单项化、功能化;加强软木产品开发利用以及软木资源的培育以提升我国软木产品竞争力,促进我国软木行业健康快速高效发展。

Field trapping of the flathead oak borer Coroebus undatus （Coleoptera： Buprestidae） with different traps and volatile lures

The flathead oak borer Coroebus undatus E （Coleoptera： Buprestidae） is one of the primary pests of cork oak Quercus suber L. in the Mediterranean region causing great economic losses to the cork industry. Very little is known about its biology and behavior and, so far, no control measures have been established. We present the results of a pilot study aimed to develop an efficient trapping method for monitoring this harmful pest. In a 3-year field study, purple-colored prism traps baited with a mixture of green leaf volatiles （GLVs） from the host have been shown the most effective combination to catch C. undatus adults （solely females） compared to other trap and lure types tested. Wavelength and reflectance measurements revealed that purple traps exhibit reflectance peak values similar to those found in the abdominal and elytral cuticle of both sexes, suggesting the involvement of visual cues for mate location in this species. The data presented are the first to demonstrate captures of adults of the genus Coroebus by an attractant-based trapping method.