落叶松毛虫(Dendrolimus sibiricus Tschetw.)生活史的初步观察

一.绪言 在祖国的东北,大、小兴安岭和长白山地区有着广大面积的针叶林和针叶与阔叶混交林。其中最主要的树种有:红松、獐子松、兴安落叶松、黄花落叶松、鱼鳞云杉、臭冷杉、蒙古栎、水曲柳、胡桃楸、黄波萝、桦、杨、榆、槭、椴等等,大多是极优良的建筑用材,     

珍稀濒危植物长白松(Pinus sylvestris var. sylvestriformis)天然种群生存压力

为了揭示珍稀濒危植物长白松（Pinus sylvestris var. sylvestriformis）天然种群生存压力状况,在全面调查长白山国家级自然保护区长白松分布的基础上,基于邻体干扰模型,引入树高、冠幅、方位等因子,提出3种生存压力指数：个体生存压力指数、种群生存压力指数和群落生存压力指数,分析天然长白松所处6种群落类型中的生存压力。结果表明：长白松承受群落生存压力（PI）从大到小依次为：白桦-臭冷杉群落（PI=21.532）、红松-长白松群落（PI=14.185）、白桦群落（PI=13.262）、臭冷杉-长白松群落（PI=8.752）、长白落叶松-鱼鳞云杉群落（PI=7.780）和蒙古栎群落（PI=5.440）。多重比较单向方差分析表明,6种群落类型中长白松生存压力总体上差异明显,白桦-臭冷杉群落中长白松生存压力最大,显著高于其他5种群落;竞争树种主要为长白落叶松、红松、长白松、山杨和白桦,这5个树种生存压力大小占群落生存压力的87%;红松-长白松群落和白桦群落中长白松生存压力无明显差异,但显著高于臭冷杉-长白松群落、长白落叶松-鱼鳞云杉群落和蒙古栎群落;臭冷杉-长白松群落、长白落叶松-鱼鳞云杉群落和蒙古栎群落中长白松生存压力相对较小,彼此无明显差异。长白松生存压力与其所处植物群落演替阶段及其龄级结构有关。目前,保护区采取严格保护和管理方式不完全有利于长白松种群的稳定发展。根据长白松种群所处的植物群落生境特点、种群生存压力状况并结合种群年龄结构特征,针对不同群落类型提出相应抚育措施建议以期为长白松天然种群的保护提供参考。     

小兴安岭主要树种热值与碳含量

对小兴安岭林区15种主要树种(红松、落叶松、鱼鳞云杉、臭冷杉、紫杉、蒙古栎、白桦、枫桦、紫椴、黄檗、水曲柳、胡桃楸、山杨、五角枫和春榆)不同器官的灰分含量、去灰分热值和碳含量进行了研究.采用快速灰化法测定灰分含量,量热法测定热值含量,吸收质量法测定碳含量.15种主要树种不同器官的灰分含量(质量分数)为:树叶0.60%～1.28%;树枝1.00%～2 98%;树干0.16%～1.22%;树皮2.15%～6.36%.15种主要树种不同器官的灰分含量(质量分数)从高到低依次为树皮、树枝、树叶、树干;不同器官的灰分含量(质量分数)具有显著差异(t检验,p < 0.01).15种主要树种平均灰分含量(质量分数)从高到低依次为春榆、山杨、蒙古栎、紫椴、黄檗、枫桦、水曲柳、鱼鳞云杉、五角枫、胡桃楸、红松、臭冷杉、紫杉、落叶松、白桦.15种主要树种不同器官的去灰分热值为:树叶20.85～22.85 kJ/g;树枝19.92～21.95 kJ/g;树干19.66～21.98 kJ/g;树皮18 58～21.74 kJ/g.15种主要树种不同器官的去灰分热值基本从高到低依次为树叶、树枝、树干、树皮;不同器官的去灰分热值具有显著差异(t检验,p < 0.01).15种主要树种平均去灰分热值从高到低依次为落叶松、红松、紫杉、鱼鳞云杉、胡桃楸、臭冷杉、山杨、五角枫、白桦、黄檗、水曲柳、紫椴、蒙古栎、枫桦、春榆.15种主要树种不同器官的碳含量(质量分数)为:树叶43 11%～45.08%;树枝44.31%～46.06%;树干46.30%～47.46%;树皮44.31%～45.46%.15种主要树种不同器官的去灰分热值基本从高到低依次为树干、树枝、树皮、树叶;不同器官的碳含量(质量分数)具有显著差异(t检验,p < 0.01).15种主要树种平均碳含量(质量分数)从高到低依次为落叶松、臭冷杉、鱼鳞云杉、红松、黄檗、紫杉、紫椴、山杨、白桦、枫桦、水曲柳、胡桃楸、五角枫、蒙古栎、春榆.针叶树种平均灰分含量普遍低于阔叶树种,平均去灰分热值和平均碳含量普遍高于阔叶树种.     

小兴安岭针叶树种在不同尺度上对环境因子的敏感性分析

 小兴安岭地区是我国重要的林区之一,预测该地区针叶树种的分布,在不同尺度上查找针叶树种分布最敏感的环境因子,是不同层次的林业部 门制定森林恢复和植树造林方针的重要科学依据。该文以坡度、坡向、综合地形指数、海拔、坡位指数、年平均温度和年平均降水量作为环境 因子,利用Logistic回归模型对红松（Pinus koraiensis）、兴安落叶松（Larix gmelinii）、冷杉（Abies nephrolepis）、红皮云杉 （Picea koraiensis)、鱼鳞云杉(P. jezoensis)和樟子松（Pinus sylvestris var. mo ngolica）的分布进行了预测。并且采用相对运行特征 (Relative operating characteristic, ROC）,对模型进行了精度评价。其取值范围为0～1, 如果ROC小于0.7,认为模型具有低精度;如 果大于0.7且小于0.9,则模型具有较好的模拟精度;如果大于0.9,认为模型具有很高的预测精度。对每个树种的模型验证表明只有冷杉的ROC 大于 80%,红松、兴安落叶松和云杉的ROC在70%～80%之间,而樟子松的为67.9%。之后,把预测模型应用到丰林保护区,揭示局域尺度上树种 分布最敏感的环境因子。经过树种分布预测图与环境因子之间的相关分析发现,在区域尺度（整个研究区）上,红松、冷杉、云杉和樟子松对 年降水量最为敏感,而兴安落叶松对坡度最敏感。在局域尺度（丰林保护区）上,红松分布对坡度最敏感,冷杉和云杉对海拔最敏感,兴安落 叶松对坡位最敏感。在不同尺度上,树种最敏感的环境因子的转移,引起了在不同尺度上树种分布类型的变化。红松在区域尺度上聚集分布 （ROC=78.6%）,而在局域尺度上其聚集程度有所减弱（ROC=74.4%）,红松的分布范围增加。在区域尺度上,云杉和冷杉聚集分布,但在局域 尺度上,它们的分布接近随机分布类型（ROC<60%）,它们在丰林保护区内分布面积较大。与以上3个树种相反,兴安落叶松的ROC从71.7%增加 到了82.0%,在区域尺度上聚集分布的兴安落叶松,在局域尺度上更加聚集,其分布范围局限于某个特定环境（谷底）。总的来说,在区域尺度 上,多数树种分布对气候因子最为敏感,在局域尺度上,对地理因子最为敏感。不同树种对不同环境因子的敏感性,揭示了树种空间分布格局 和分异规律。     

高CO2浓度对温带三种针叶树光合光响应特性的影响

将长白山地区阔叶红松林中主要针叶树种红松、红皮云杉和长白落叶松的幼苗 ,盆栽于模拟自然光照和人工调节CO2 浓度为 70 0和 40 0 μmol·mol-1的气室内两个生长季 ,在各自的生长环境条件下 ,利用CI 30 1PS便携式CO2 分析系统测定针叶的光合光响应曲线 .结果表明 ,不同树种及同一树种的不同CO2浓度处理间差异明显 .比较饱和净光合速率、暗呼吸、光补偿点、光饱和点、及光能利用率 (QUE)的变化可见 ,长白落叶松为阳性树种 ,其光合作用对高CO2 浓度的适应能力较好 ,红松树种次之 ,阴性树种红皮云杉光合作用对高CO2 浓度适应能力最差 .并初步探讨了供试树种光合生理特性及其演替状况间的联系     

长白山地区不同林型红松种群生态位特征

采用Levins、Hurlbert生态位宽度和Pianka生态位重叠计测方法,分析长白山地区不同林型红松种群生态位特征。结果表明,红松种群是长白山地区顶极群落原始阔叶红松林的优势种群,其生态位宽度呈现原始阔叶红松林白桦林落叶松阔叶混交林。相比于其他种群的生态位宽度,总体上原始阔叶红松林中耐阴树种的生态位宽度较大,阳性树种的生态位宽度较小,而次生林则相反。在生态位重叠方面,红松与各林型中其他种群表现出不完全重叠。在原始阔叶红松林和白桦林中,红松与其他乔木种群对资源有明显的共享趋势。红松与原始阔叶红松林的色木槭、紫椴、青楷槭、白桦,与落叶松阔叶混交林的紫椴、蒙古栎、长白落叶松,与白桦林的色木槭、白桦,对同一资源有相同或相似的要求,且当资源不足时会产生竞争。     

长白山主要树种耐旱性的研究

研究表明,全球增温可导致干旱趋势的发展,为了解东北主要森林分布区长白山广大低海拔地区阔叶红松林主要组成树种对干旱趋势的反应,通过ＰＶ曲线技术测定不同树种的水分参数值,比较评价其耐旱能力,得到长白山阔叶红松林主要树种耐旱性从高、到低依次为：山杨、蒙古柞、樟子松、红松、长白松、黑桦、春榆、色木、糖椴、紫椴、红皮云杉、白桦、臭松、水曲柳、核桃楸、黄菠萝。     

东北东部山区11种温带树种粗木质残体分解与碳氮释放

采用长期定位跟踪实测方法,比较分析了我国东北温带森林4个水热状况不同的立地条件(红松(Pinus koraiensis)人工林、硬阔叶林、蒙古栎(Quercus mongolica)林和林外空旷地)下11个温带树种粗木质残体(CWD)分解初期3年中的碳氮动态及其影响因子。测定树种包括:白桦(Betula platyphylla)、山杨(Populus davidiana)、紫椴(Tilia amurensis)、胡桃楸(Juglans mandshurica)、蒙古栎、色木槭(Acer mono)、春榆(Ulmus japonica)、红松、黄檗(Phellodendron amurense)、兴安落叶松(Larix gmelinii)和水曲柳(Fraxinus mandshurica)。结果表明:在分解过程中,所有树种CWD的碳浓度没有明显变化(p0.05),但其干重、碳密度、氮浓度和氮密度均随分解进程不同程度地减小,碳氮比(C/N)则增大,而且树种间差异显著(p0.001)。针叶树种的CWD分解速率显著地低于阔叶树种,其中白桦的3年CWD干重损失率(65%)约为兴安落叶松(22%)的3倍。径级大的CWD分解较慢。CWD分解与碳氮释放均与CWD的初始N含量呈正相关,而与初始C/N呈负相关。4个立地条件下CWD的干重和碳氮含量的变化差异不显著,均表现出一致的变化趋势。该研究指出,在分解初期的前3年中,CWD基本上是一个碳源和氮源。     

大兴安岭中部天然次生林种子雨动态

本研究于2018—2019年对大兴安岭中部白桦林、针叶林和针阔混交林3种林型的种子雨落种量进行了动态监测,并对3种林型主要树种的种子雨季节动态、落叶动态、种子雨千粒重、种子雨年际变化和种子雨空间格局进行了分析。结果表明: 各林型中兴安落叶松种子雨和白桦种子雨呈现明显的单峰型分布。针阔树种(落叶松、樟子松、云杉、白桦、山杨)的落叶量呈现出明显的季节动态,各林型落叶量大多在9月中上旬达到高峰。在针阔混交林和针叶林中,处于高峰期的兴安落叶松种子雨千粒重明显大于初始期和末尾期的兴安落叶松种子雨千粒重,3种林型下白桦千粒重在季节上未表现出明显的差异。兴安落叶松和白桦的种子雨均呈现出明显的年际变化,2018年为种子散种量的丰年,2019年为歉年。两年时间内,所有种子雨的空间格局在总体上均表现为聚集分布,种子雨和幼苗幼树在空间分布格局上存在一致性。     

东北林区4个天然针叶树种单木生物量模型误差结构及可加性模型

基于276株实测生物量数据,构建了东北林区红松、臭冷杉、红皮云杉和兴安落叶松4个天然针叶树种总量及各分项生物量一元、二元可加性生物量模型.采用似然分析法判断总量及各分项生物量异速生长模型的误差结构(可加型或相乘型),而模型参数估计采用非线性似乎不相关回归模型方法.结果表明: 经似然分析法判断,4个天然树种总量及各分项生物量异速生长模型的误差结构都是相乘型的,对数转换的可加性生物量可以被选用.各树种可加性生物量模型的调整后确定系数R_a²为0.85～0.99,平均相对误差为-7.7%～5.5%,平均相对误差绝对值<30.5%.增加树高可以显著提高各树种可加性生物量模型的拟合效果和预测能力,而且总量、地上和树干生物量模型效果较好,树根、树枝、树叶和树冠生物量模型效果较差.所建立的可加性生物量模型的预测精度为77.0%～99.7%(平均92.3%),可以很好地预估东北林区天然红松、臭冷杉、红皮云杉和兴安落叶松的生物量.
     

中国西南地区土地覆盖情景的时空模拟

气候植被类型的空间分布与土地覆盖类型的空间分布在时空层次上具有很好的相关性和一致性。在运用HLZ生态系统模型获得CMIP5的3种气候情景RCP26、RCP45、RCP85情景下西南地区未来90a(2011—2100年)HLZ生态系统时空分布情景数据的基础上,结合2010年土地覆盖现状数据,构建了土地覆盖情景的空间分析模型,并在此基础上,实现了西南地区未来90a土地覆盖情景的时空模拟分析。模拟结果表明:3种气候情景下,西南地区未来90a的落叶针叶林、落叶阔叶林、草地、耕地、冰雪、荒漠及裸岩石砾地等土地覆盖类型面积将呈逐渐减少趋势;常绿针叶林、常绿阔叶林、混交林、灌丛、湿地、建设用地、水体等土地覆盖类型面积则呈逐渐增加趋势。其中,湿地增加速度最快(平均每10a增加5.28%),荒漠及裸岩石砾地减少速度最快(平均每10a减少2.34%)。     

Nitrogen use scenario in India

Nitrogen is one of the major plant nutrients without which the agricultural production is not possible. Nitrogen use in Indian agriculture was nearly 55000 tons in 1950-1951 that increased to 11.31 million tons in 2001-2002. The total food production of the country has also experienced the similar increase from 50.83 to 222 million tons in the respective years. Interestingly the N fertilizer consumption of India remained almost constant during the last six years indicating the possibility of reducing N consumption. The highest N consumption is in North zone owing to the introduction of rice-wheat cropping system followed by West, South and East.The N use efficiency has been reported to be varying between 30% to 50% depending on the crops and the management. But in most of the cases, N use efficiency has been calculated based on the total N removed by the crops (above ground part only) ignoring the N content left in the roots. It has been observed in controlled experiments that the total N uptake by roots varied from 18% to 44% of the total N removed by the above ground parts, i.e. grain and straw. If the root N is also accounted, the N use efficiency will be higher than reported. The management of other organic sources has to be improved so as to increase the fertilizer use efficiency as well as to check the direct release of N in the atmosphere. In this review all these issues will be dealt.     

Risk Assessment Using EUSES; Refinement Options to Estimate Atmospheric Transportation by its Operational Priority Substances Model (OPS)

The Operational Priority Substances (OPS) model is part of the European Union System for the Evaluation of Substances (EUSES) and is used to estimate air concentrations and atmospheric depositions for risk assessment of chemicals. Traditionally, EUSES assesses environmental exposure using a standardized scenario based on explicit assumptions and default parameter settings. Under the new European Union REACH legislation—which stands for Registration, Evaluation, Authorisation, and restriction of Chemicals—industry is responsible for the risk assessment of chemicals. The current work investigates the potential impact and importance of source parameter refinement on the emission distribution and environmental fate of chemicals as modelled by OPS. In total, 60 scenarios with different combinations of (non) default values for emission heat content, emission source height, and emission source radius, were run for a typical particle-bound substance. Increasing heat content and emission source height reduced the modelled air concentrations and depositions and caused maximum air concentrations to occur further away from the emission source. Results show that estimated air concentrations and total depositions used for risk assessment can become more realistic by using more site-specific emission source parameters. This article proposes risk assessment refinement options and provides recommendations on future updates of EUSES.     

The hard choice for alternative biofuels to diesel in Brazil

This paper selects biofuel scenarios to substitute diesel in Brazil based on oil reserves increase, diesel imports, CO₂ emissions, crops agronomic yields, byproducts marketing and social impacts. This hard task still considers that agricultural practices in developing countries have large social impacts. Brazil presents high consumption of diesel oil in transport; low agronomic yield of traditional vegetable oil crops, which demand large cultivation areas contrasting with microalgae and palm oils which present high productivity. Concerning technologies, thermal cracking and transesterification of vegetable oils present a difficult economic situation related to vegetable oils price, food competition and glycerin market; BTL technology, meaning thermal gasification of biomass to liquids, faces problems related to low density of biomaterials and low viscosity of synthetic biodiesel produced. Biorefinery algal integrated systems and co-solvent technology to introduce up to 8% of ethanol into diesel seem to be feasible routes to reduce diesel consumption.     

Nitrogen use scenario in India

Nitrogen is one of the major plant nutrients without which the agricultural production is not possible. Nitrogen use in Indian agriculture was nearly 55000 tons in 1950-1951 that increased to 11.31 million tons in 2001 -2002. The total food production of the country has also experienced the similar increase from 50.83 to 222 million tons in the respective years. Interestingly the N fertilizer consumption of India remained almost constant during the last six years indicating the possibility of reducing N consumption. The highest N consumption is in North zone owing to the introduction of rice-wheat cropping system followed by West, South and East. The N use efficiency has been reported to be varying between 30% to 50% depending on the crops and the management. But in most of the cases, N use efficiency has been calculated based on the total N removed by the crops (above ground part only) ignoring the N content left in the roots. It has been observed in controlled experiments that the total N uptake by roots varied from 18% to 44% of the total N removed by the above ground parts, i.e. grain and straw. If the root N is also accounted, the N use efficiency will be higher than reported. The management of other organic sources has to be improved so as to increase the fertilizer use efficiency as well as to check the direct release of N in the atmosphere. In this review all these issues will be dealt.     

情景模拟在“医学微生物学”翻转课堂教学中的应用

翻转课堂是实现以学生为中心、提升学生自主学习能力的重要教学方法。随着线上课程的开展和学习平台技术的成熟,学生已能在课前获得足够的资源。然而,习惯于灌输式教育的学生仍缺乏自主学习的动力和方法。为此,我们教研团队尝试采用情景模拟的课堂活动设计来突破翻转环节实施的难点。研究发现,参考临床案例撰写剧本的过程能有效提升学生的自学兴趣和能力。学生课前在线预习时长和章节访问次数,以及参考资料阅读率和小组讨论时长均显著增加。课堂上,学生将课前所学知识在模拟实践中进行练习,促进了师生互动,帮助学生加深对知识的理解,提升学习成绩和满意度,同时也培养了学生的团队合作精神,建立临床思维,提升职业兴趣和能力。因此,情景模拟的融入实现了翻转课堂教学中“课前学”和“课上习”的教学闭环,为进一步推进翻转课堂的开展提供参考。     

基于LEAP的厦门市节能与温室气体减排潜力情景分析

城市是人类社会经济活动的中心,聚集了世界一半以上的人口。在城市发生的温室气体排放量占全球排放总量的75%左右,因此在城市这个尺度上研究温室气体减排意义重大。从城市这个尺度出发,以厦门市为实际研究案例,应用LEAP模型进行节能减排政策情景分析,定量分析评价城市节能减排潜力,并详细分析各种控制情景和各部门的节能减排贡献率。研究结果显示:在综合控制情景下,厦门能源消费总量年均增长率、万元地区生产总值能耗和温室气体排放总量年均增长率都有所下降;清洁燃料替代措施节能减排效果最好,工业部门节能减排潜力最大;优化能源使用结构蕴藏巨大减排潜力。     

Modeling and Optimization of a Coal‐Chemical Eco‐industrial System in China

China is coal dependent, and this situation will persist for a long time. Because more and more attention has been paid to energy security, the coal‐chemical industry has become a hot topic and has developed quickly. To improve efficiency and reduce emissions, industrial symbiosis (IS) can be introduced when establishing a coal‐chemical eco‐industrial system to achieve harmonious development between nature, industry, and society. In order to learn the influence of IS on the current industrial system, a model of coal‐chemical eco‐industrial systems was built. Using scenario optimization and linear programming, the behaviors and optimal industrial structures of the system under different scenario settings were compared, and industrial ecological analysis was performed. By comparative analysis, results showed that the greatest proportional decrease in the use of coal for coking was 15% compared with actual data for 2005. The resource‐productivity and eco‐productivity were 828 yuan/ton and 2.51, which are much higher than the values of 548 yuan/ton and 1.23 in 2005. The symbiosis index and the link density were found to be 0.675 and 1.67, compared with 0.588 and 0.94 in 2005. Research results showed that the coal‐chemical eco‐industrial system achieved a high value‐added utilization of coal and an updated product profile. Such systems will constitute the main direction and the inevitable trend of China's coal utilization in the future, which will reduce the harm to the environment from increased coal use and benefit the energy industry, the economy, and society.     

What-If Scenario Modeling to Support Oil Spill Preparedness and Response Decision-Making

Scenario analysis (SA) is the process of developing plausible futures around the forces affecting an organization in the face of uncertainties over which it has little control. SA is widely used in the private sector and increasingly a tool of environmental planners grappling with problems of great complexity and uncertainty. SA ideally marries expert judgment with the broader perspectives engaged stakeholders bring. While the 1990 Oil Pollution Act (OPA) brought substantive improvement to oil spill contingency planning, many issues remain. Reguatorily prescribed definitions of ‘worst case’ lead to SA practice that seldom achieves the full promise of the SA approach. Contingency planning overly focused on tactical and operational considerations can leave response managers little prepared to deal with public concerns that emerge in the event of a major spill, concerns increasingly magnified through social media. Politics continues to contribute to poorly conceived contingency planning in which adopted scenarios bear little resemblance to events that subsequently transpire. Risk attenuation and risk amplification both inhibit scenario-based planning around oil spills, evinced by the Deepwater Horizon spill. Improvements in pre-planning in the aftermath of the Exxon Valdez oil spill nevertheless provide a foundation for more effective use of SA.     

低碳导向下土地覆被演变模拟——以深圳市为例

全球碳排放水平的不断增加引起的全球变暖越发严重,导致了严重的自然灾害和经济损失,这种失衡发展的态势促使着各个国家开始探索低碳环保的发展模式。为了探究何种土地利用组成可以更好的为低碳城市服务,以深圳市为研究区,结合2020年土地利用现状结构和2020年土地利用规划结构分别估算出碳汇最大化情景和碳排放量最小化情景下2020年各土地利用类型的数量结构,并运用FLUS模型模拟出深圳市土地利用类型在这两种情景下的空间分布特征。最后,从碳密度和碳排放视角对比这两种情景的低碳效益。研究结果如下：①碳汇最大化和碳排放最小化情景下土地利用总碳盈余均比2020年少,且碳汇最大化情景下土地利用总碳盈余最小。碳汇最大化情景下耕地、园地和林地面积增加而水域和建设用地减少,碳排放最小化情景下园地和林地面积增加来源于草地、水域和建设用地的减少,这两种低碳情景的碳汇能力增强而碳排放量减少;②碳汇最大化和碳排放最小化情景下林地明显增加故而土地利用总碳盈余均比实际情景小,而园地和草地的缩减和扩张是引起两种低碳情景碳密度和碳排放量有差异的主要原因。碳汇最大化和碳排放最小化情景下,西部和东南部主要是碳密度增加和碳排放减少的区域,而中部是碳密度减少和碳排放增加的区域。因此对中部区域进行重点调控,有利于深圳市碳中和和碳达峰的实现。研究可以为深圳的低碳发展提供规划建议,同时给其他区域的低碳规划提供参考意见。