Fossil history and modern distribution of the genus Abies (Pinaceae)

The plants of the genus Abies are dominant and key species in the dark coniferous forest in the Northern Hemisphere. There are 52 species, one subspecies and 12 varieties in the genus Abies in the world. The history and modern distribution of Abies were discussed. The genus has three modern distribution centers: South Europe, North America and East Asia. These areas are also rich in fossil records. The vertical distribution regions of Abies are from sea level to an elevation of 4,700 m, concentrated in 1,000–2,000 m (15 species). In China, the genus distributes in 20 provinces, especially abundant in the Hengduan Mountains. Meanwhile, endemic and relic phenomena are obvious in this genus. There are seven relic species with both limited individuals and limited distributed regions. Based on the fossil records and the latest phylogenetic data, the following hypothesis was proposed: Abies originated from the middle and high altitudes of the Northern Hemisphere in the middle Cretaceous and it was dispersed southward in the Eocene due to global climate cooling down. The distribution of Abies was deeply influenced by geological events such as the uplift of Himalaya, the Alps, the Rocky Mountains, the occurrence of the Asian Monsoon as well as the Quaternary glaciers. Finally, the current distribution pattern appeared in the Quaternary. The genus Abies has a fossil history and modern distribution pattern similar to that of Cathaya and Pseudolarix. __________ Translated from Acta Botanica Yunnanica, 2006, 28(5): 439–452 [译自: 云南植物研究]     

陕西省秸秆资源能源化潜力评价

农作物秸秆是一种重要的生物质能源。由于滞后的思维方式、传统的观念以及技术落后等问题而造成大量的农作物秸秆仍无法取得高效的利用,陕西省的农作物秸秆资源利用率仅不到30%,剩下的70%多仍为废弃、焚烧等方式粗犷利用,导致环境污染严重、能源大量流失。通过对陕西省2011年的农作物秸秆产量进行分析,利用统计数据,计算出可利用的秸秆资源量,并将可利用秸秆资源量转化成标准煤量,为陕西省秸秆资源利用提供基础数据及决策参考,得出假设:将所有的可收集利用秸秆资源完全用作能源使用,计算得2011年陕西省农作物秸秆可收集利用资源量1 196.82万t,折合标准煤663.56万t,约占当年陕西省总能源消耗的6.55%。     

广东地质发展简史及植物区系溯源

广东植物区系的发展由来已久，现代的广东植物是晚白垩世或早第三世的孑遗物，地层中存在磊量的古植物化石。如本内苏铁，银杏，苏铁等极为丰富，种子特别是大羽羊齿尤为突出，而且在白垩纪晚期至第三纪的广东地层中，存在着丰富的现代植物的化石或化石孢粉组合，如朴树，桦木、鹅耳枥及松、冷杉、雪松等，还有其它阔叶树和针叶树，所有这些都与广东复杂的地质发展史密切相关，它预示着广东植物区系可能起源于亚带山地，而且广东无颖     

西藏拉萨地区5000a来古气候古环境变迁

根据西藏拉萨桑达第四系剖面的研究,采用植硅体、分子化石等气候待用指标,并配以TL测年,探讨了拉萨地区5000a来气候及环境变迁.结果表明:1)在5.889Ka.BP-2.3 Ka.BP,植硅体形态类型为齿形-平滑棒型、石屑型、网脊块状,反映的植被景观为森林-草原景观,气候温凉;C27+C29/C31+C33值>1,木本...     

Carbon Accumulation and Fossil Fuel Substitution During Different Rotation Scenarios

Accumulation of carbon (C) in biomass and soil, and using forest residues for bioenergy are examples of forestry’s contribution to reducing the enhanced concentration of greenhouse gases in the atmosphere. The aim of this report was to study the effect of rotation length on carbon accumulation in biomass and soil, and on the amount of forest residues that could substitute fossil fuel during 2000–2100. Two models, based on inventory data from the Swedish National Forest Inventory, were used to simulate the effects of a changed rotation length in the region of Dalarna (1.8 × 10⁶ ha), in central Sweden. During the studied period, the accumulation of carbon in biomass was 32 kg C ha^?1 yr^?1 larger for the prolonged rotation period and 105 kg C ha^?1 yr^?1 smaller for the shortened rotation period compared with the base scenario. The build-up of carbon in forest soil was 23 kg C ha^?1 yr^?1 larger for the prolonged rotation than for the base scenario, whereas the shortened rotation was 24 kg C ha^?1 yr^?1 smaller than the base scenario. The potential to substitute fossil fuel was 37 kg C ha^?1 yr^?1 larger for the shortened rotation and 17 kg C ha^?1 yr^?1 smaller for the prolonged rotation compared with the base scenario. The annual accumulation of carbon in biomass decreased in all scenarios, which resulted in a prolonged rotation scenario possibly being a poor long-term solution (> 100 yrs). The amount of forest residues that could substitute fossil fuel increased in all scenarios during the studied period.     

The barnacle and the building: a modern morality tale

A rare and almost complete barnacle fossil, previously described on the basis of two isolated shell fragments, was recently exposed in a limestone block on the outer wall of Melbourne's Old Magistrates' Courts in Victoria, Australia. These courts comprise one of the oldest and grandest buildings in Melbourne and because of this they have a heritage listing. As heritage‐listed buildings are protected from alteration by law, and as removal of the fossil would be deemed “alteration”, official permission had to be obtained to extract the specimen. This paper discusses the processes involved with extraction of a unique specimen from a protected building and provides an overview of the palaeontological significance of the fossil. Consideration is given to the likely fate of a fossil of this nature, situated a little below eye level on a busy city street, if it was left in situ; finally, the implications of designating a holotype from material removed from a building are assessed.     

Reconstructing the history of human impacts on coastal biodiversity in Chile: constraints and opportunities

• 1. Although Chile is at the forefront in evaluating experimentally the importance of human harvesting impacts on coastal biodiversity, there are no evaluations of such impacts on a long‐term historical basis (tens to thousands of years). Different types of archival information (i.e. contemporaneous, archaeological, and palaeontological) were used to carry out a research programme based on the historical assessment of the impacts and intensity of resource extraction on coastal biodiversity along the Chilean coast.
• 2. In addition to recent scientific literature, different sources of contemporaneous information (e.g. museum collections, old reports and accounts) can reveal the human impacts observed in the more recent past. Furthermore, the large number of prehistoric shell middens along the entire Chilean coast offer access to ～11 000 years of history along the entire coast, although the faunal composition, structure, and dynamics of most of them remain largely unstudied.
• 3. Finally, the rich and widespread fossil record of some marine groups provides the opportunity to reconstruct the structure and dynamics of benthic communities during different phases of human influence (e.g. pre‐human, prehistoric harvesting, and modern harvesting).
• 4. Preliminary comparisons of fossil versus modern bivalve assemblages suggest marked changes in the species composition. Human impacts seem very recent and shifts in the structure of benthic assemblages may have occurred only a few centuries/decades ago.
• 5. In contrast, prehistoric harvesting, although intense, was apparently not enough to cause a profound impact on coastal ecosystems. The approach herein envisaged can provide the basis to build a historical baseline to evaluate the human impacts on the coastal biodiversity in the region. Copyright © 2009 John Wiley & Sons, Ltd.

     

烤烟漂浮育苗风化石替代草炭基质研究初报

以风化石为主要原料,蔗渣、药渣为辅料,组合成4个基质配方,以常规草炭基质为对照进行育苗对比试验,研究不同风化石含量配以一定量的有机质辅料对烟苗出苗率、成苗率以及不同阶段烟苗素质的影响.结果表明,40％～70％风化石加一定蔗渣、药渣所育烟苗均能达到壮苗标准.其中40％风化石含量的基质处理出苗率和成苗率比对照分别提高4.02个百分点和1.48个百分点;50％风化石含量的基质处理茎叶及根系干物质累积75 d时分别比对照增加0.13和0.05g.其他几个基质配方所育烟苗的千物质累积、地上部分-地下部分协调性及成苗素质等指标都与对照接近,甚至优于对照;育苗成本较对照降低47.8％～56.2％,说明以风化石为主要原料来代替草炭作烤烟漂浮育苗基质完全可行.     

原生动物起源的模糊性问题及其解决途径

原生动物起源是动物学、生物进化论研究的重要内容之一,原生动物的元祖生物的起源与演化等诸多问题尚不清楚．根据古生物学和现代生物进化论研究的成就,就原生动物起源中起源形成动物、起源生物及其不确定原因进行分析,提出几种理论假设及解决途径．     

Performance and environmental effects of forage production on sandy soils. III. Energy efficiency in forage production from grassland and maize for silage

Based on experimental data gathered in a research project on nitrogen fluxes in intensive dairy farming in Northern Germany, an analysis of fossil energy input and energy efficiency in forage production from permanent grassland and maize for silage was conducted. Field experiments comprised different defoliation systems and different rates of mineral N fertilizer and slurry application. Each change from grazing to cutting in grassland systems reduced the energy efficiency. Energy efficiency consistently decreased with increasing rates of mineral N application. In the production of maize for silage, maximum energy efficiency was obtained with an application of 50 kg N ha^?1 from slurry only. Net energy yields of maize for silage were much higher than that of grassland when compared at the same level of fossil energy and nitrogen fertilizer input. Considering both nitrate‐leaching losses and a necessary minimum quantity of grass herbage in a well‐balanced ration, it is suggested that a high proportion of maize for silage in combination with N‐unfertilized grass/clover swards used in a mixed cutting/grazing system represents a good trade‐off between the leaching of nitrates and energy efficiency.