Seasonal changes in susceptibility of Quercus suber to Botryosphaeria stevensii and Phytophthora cinnamomi

Monthly inoculations of both intact plants and excised shoots of Quercus suber with the pathogenic species Botryosphaeria stevensii and Phytophthora cinnamomi were performed to investigate seasonal changes in susceptibility of this forest tree species in relation to environmental parameters and plant water status. Infection symptoms were mainly detected on seedlings inoculated from spring to autumn (April through October) with either pathogen. Mean canker sizes also showed a seasonal pattern, the higher values being recorded in the same period as above. Lesion lengths were significantly ( P  < 0·001) related to environmental minimum temperature. Mean daily minimum temperatures within the range of 5–12°C clearly inhibited lesion development of P. cinnamomi , whereas B. stevensii showed a less pronounced decrease in canker expansion at the same temperature range. In excised shoots of Q. suber inoculated monthly with B. stevensii , a negative linear relationship was found between the studied range of plant relative water content (81–91%) and canker length. In contrast, the lesions caused by P. cinnamomi were not significantly ( P  = 0·32) related to any seasonal change in water content. Some control measures for the diseases caused by both pathogens are discussed on the basis of the seasonal changes in host susceptibility observed in this study.     

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。     

新型软木橡胶复合地板的生产工艺和性能测定

介绍一种软木橡胶地板的生产工艺,并对其性能进行检测和分析。结果表明:该软木橡胶地板的含水率、抗拉强度、初始压缩度和残留压缩度等指标,均可达到标准LY/T 1657-2006《软木类地板》的要求。     

Effect of land use on forest floor and soil of a Quercus suber L. forest in Gallura (Sardinia,Italy)

In order to determine the effect of land use on forest floor and soil, two adjacent sites with different land use were investigated in Gallura (northern Sardinia, Italy). One site is a Quercus suber L. forest mainly used for cork production and the other is an open Quercus suber L. forest where livestock is put out to graze. In each site one soil profile was studied to characterize the mineral soil, and five humus profiles were opened along a vegetation transect, were studied to characterize the forest floor. Samples of L, F and H horizons of the forest floor and of the A mineral horizons were collected and analysed for each profile. In the site mainly used for cork production well‐developed ectorganic (L, F and H) horizons are always present, with a total thickness ranging from 5·2 to 9·5 cm. Humus profile is of the Moder type, while mineral soils have an A–C profile, generally 50 cm deep. Organic matter content in the forest floor ranges from 1·76–3·72 kg m⁻² and nutrients content in the mineral soil is high. In the site used chiefly for grazing the ectorganic horizons are very poorly developed, with a total thickness ranging from 1–3 cm, except for some islands under the Quercus suber L. canopy where the total thickness may reach 5·3 cm. Humus profile is of the Mull type, but the used classification system seems not appropriate when the tree density is below a critical limit. Mineral soils have an A–C profile 20–25 cm deep. The organic matter content in the forest floor ranges from 0·45 to 1·84 kg m⁻², while nutrient content in the mineral soil maintains at high level, even higher than in the former case for C, N and Ca, probably in relation with higher supply of cattle excreta. Sheet erosion is evident in the site. It is concluded that cork production will maintain a sustainable forest floor development in cork–oak forest ecosystem, whereas cattle grazing, fires and ploughing in cork–oak forests may be considered to trigger off severe soil degradation processes. Copyright © 2000 John Wiley & Sons, Ltd.