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The present study is about in vitro culture of cork oak, through callogenesis from nodes and internodes, withdrawn from seedlings of three months.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.

Assessment of Cork Oak Decline Using Digital Multispectral Imagery in Relation with in Situ Crown Condition

Cork oak in Maamora forest is experiencing the dieback phenomenon. The evaluation of the latter in this forest has gained the importance over time and with the solicitation of managers to objectify its phytosanitary situation. Aiming at prioritizing management actions, remote sensing seems to be an effective tool to inquire about stands’ health conditions and their evolution. To this end, this study aims at mapping and validating health status of cork oak stands in Maamora. Sentinel 2 images in 2015 and 2020 were processed to calculate the differential normalized difference water index (NDWI), revealing vegetation moisture variation caused by drought. A statistical method based on thresholds was used to map cork oak dieback stands, those with no changes and those recovered. Results have shown that 54.63% of cork oak in Maamora forest have not changed in terms of phytosanitary situation between 2015 and 2020, 31.10% of oak stands are afflicted by a slight decline and 12.97% by a severe decline. Areas with slight or strong recovery remain minimal and represent 1.04% and 0.25% respectively. Ground data indicated that the map generated displayed a good distinction between stands severely and slightly declined with a global accuracy of 66.66%. Therefore, further research elaborating an advanced vegetation index reflecting the various factors of dieback would be of much importance.

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.

Nitrogen and Organic Matter Mineralization in the Tunisian Cork Oak Forest: A Laboratory Study

The mineralization of the organic matter is a very important phenomenon which leads to the release of nutriments used by plants. The rate of transformation of the organic matter depends on several factors and parameters such as climatic factors and biological and physicochemical properties of the soil and the litter. In this study, we investigate the effect of the addition of litter of various species as well as the effect of soil moisture on mineralization of organic matter and on mineral nitrogen release in three soils sampled in three cork oak stands during a period of 41 days under the same laboratory conditions. Carbon mineralization was determined using CO2 respiration method, whereas the mineral nitrogen content was measured at the last day of incubation both in soil samples with added plant leaf material, and in control soil samples without addition under two treatments of moisture (40% and 80% WHC—water holding capacity). Our results show that the addition of leaf litter causes an increase in the microbial activity. Soils without addition were significantly different from the plant leaf added soils in respect to carbon mineralization at the end of the incubation period. Moreover, it is noted that the mineralization of carbon is more marked with moisture at 80% than that of 40%, contrary to that of the nitrogen, which is not influenced by the variation of moisture.

Predicting Cork Oak Suitability in Maâmora Forest Using Random Forest Algorithm

Maamora is considered the most important cork-oak forest in the world with regard to surface. Therefore, anthropic pressure, including cork harvesting, grazing and soft acorn picking up by local communities, has harmful consequences on forest regeneration and the forest become older exceeding harvesting age. Thus, its sustainability depends on the managers’ ability to succeed cork oak plantations. This work presents an assessment approach to evaluate Quercus suber suitability to its plantation which is based on a random forest algorithm (RF). In fact, this suitability has been assessed through analyzing management data related to previous plantation success rates (SR). Then a relationship between SR and a set of environmental and social factors has been investigated using the RF. Application of the fitted model to continuous maps of all involved factors enabled establishment of suitability maps which would help managers to make more rational decisions in terms of cork oak regeneration, ensuring Maamora forest sustainability.

种子产量对鼠类扩散栓皮栎坚果的影响

为了解林木种子产量对鼠类种子扩散行为的影响,于2008年和2009年,在国有济源市愚公林场调查了栓皮栎的种子雨;在每年的种子雨结束后,选择次生林生境,研究了鼠类对人工释放栓皮栎坚果的扩散,旨在探讨种子产量与种子扩散间的关系。结果表明:1)取食栓皮栎坚果的鼠类主要有大林姬鼠、社鼠和岩松鼠,2008年的鼠类捕获率(2%)低于2009年(10%),其差异并未达到显著性水平;2)栓皮栎的种子雨构成和产量存在年际差异,2008年以完好种子为主且产量高于2009年,而2009年以败育种子为主;3)2008年人工释放栓皮栎坚果的中位存留时间显著高于2009年;4)2008年鼠类对栓皮栎坚果的平均扩散距离显著低于2009年,且两年的搬运距离几乎都集中在9m以内;5)2008年鼠类对栓皮栎坚果的埋藏比例显著高于2009年。结果提示,在种子高产年份,可能有较多的种子逃脱动物的取食,从而增加种子萌发和幼苗建成的机会,最终促进植物的更新。

生境类型对啮齿动物扩散和贮藏栓皮栎坚果的影响

在河南省济源市王屋山地区,研究了次生林、灌丛、退耕地三个生境中啮齿动物对栓皮栎坚果的取食、扩散与贮藏情况。结果表明:1)在研究地区,取食栓皮栎坚果的啮齿动物主要有大林姬鼠、社鼠和黑线姬鼠;2)在次生林中,啮齿动物对坚果的搬运速率慢于在灌丛和退耕地生境中的搬运速率;3)次生林生境中,贮藏坚果占被扩散坚果的比例高于灌丛和退耕地,而灌丛生境中被取食坚果占被扩散种子的比例高于退耕地和次生林;4)栓皮栎坚果的中位存留时间在三个生境间有显著性差异。研究结果提示,在人工造林时,可通过对栓皮栎坚果进行埋藏处理,以提高种子萌发率。

栓皮栎人工林林下物种多样性的影响因子

以物种丰富度指数(S)和Shannon-Wiener多样性指数(H)反映北京平谷区四座楼自然保护区栓皮栎(Quercusvariabilis)人工林林下物种多样性特征,采用一般线性模型结合方差分析研究环境因子与林下物种多样性的关系,最后通过逐步回归分析找出影响林下物种α多样性的主要环境因子。结果表明:影响栓皮栎人工林灌木层和草本层物种多样性变化的主要环境因子是有区别的,影响灌木层α多样性变化的主要解释因子是林分光照条件(如林冠空隙比例)和地形因素(如坡度),而影响草本层物种α多样性变化的主要解释因子是林龄。这些差异既与灌木、草本植物的生理生态特性有关,也反映了群落内部不同层次间复杂的相互作用。

改进栓皮栎树高预测混合效应模型研究

树高与胸径是森林资源调查中2个重要的测树因子。鉴于树高测量相对不易实现的问题,以金华市永康市西溪镇的94株栓皮栎树为研究对象,在比较林业上常用的10个树高曲线模型拟合效果的基础上,改进了传统的Gompertz树高曲线模型,提出并构建了含有立地因子的Gompertz混合效应树高预测改进模型。实验表明:1)当对Gompertz混合效应模型拟合时,引入随机参数b_1,b_3时模型拟合最好;当对Gompertz混合效应改进模型拟合时,引入随机参数b_1,b4时模型拟合最好。2)构建的Gompertz混合效应改进模型决定系数达到0. 779,Gompertz混合效应模型决定系数为0. 553,Gompertz模型决定系数为0. 542,即仅凭混合效应方法构建模型对提高模型预测精度并不明显。实验证明了本文构建的Gompertz混合效应改进模型大大提高了栓皮栎的树高预测精度,为研究树种树高-胸径关系模型提供了一种新方法。

对西安市长安区林业创新发展的思考

概述了西安市长安区林业发展的状况以及存在的问题,指出了创新发展是当前新形势下林业发展的模式,认为大力发展栓皮栎林是未来长安区林业发展的有效途径,并分析了软木工业国内外发展状况以及在长安区发展的可行性与优缺点。

山西省古稀柞树资源的调查

壳斗科栎属树种统称为柞树,山西省有许多的柞树资源。调查了与柞蚕有紧密关联的8个树种14个不同地点22株古稀树木,介绍了这些树木的遗存及生长情况。

北京妙峰山地区栓皮栎林物种多样性的研究

在2005年进行样地调查获得原始数据的基础上,对妙峰山地区栓皮栎林的物种丰富度、物种多样性指数和群落均匀度,以及植物区系成分和群落结构特征进行了初步研究。结果表明,北京妙峰山地区栓皮栎林群落区系组成丰富,外貌结构典型,植物物种多样性较高。物种多样性指数、均匀度、丰富度指数在群落梯度上的总体趋势表现为草木层>灌木层>乔木层。