滨海湿地原生灌草群落土壤养分与盐分关系

通过灌草群丛划分、土壤采样以及室内测定、数理统计等方法,分析了黄河三角洲原生湿地灌草群落土壤的养分、盐分分布特征及相互关系,发现原生灌草群落土壤可溶性盐的垂直分布变异性较大,其中,碱蓬群丛与柽柳群丛土壤可溶性盐分布具有较强的表聚性,而土壤有机质含量表现为芦苇群丛>柽柳群丛>碱蓬群丛,且灌草群落中土壤C/N值都大于5,表明其有机质腐殖化程度较高。另一方面,土壤全氮与有机质存在明显的线性正相关;而土壤全盐与有机质、全氮之间存在明显的倒数关系,表明全盐对二者的制约作用,其中15~20g/kg的土壤盐分范围对应的是土壤全氮、有机质由迅速减少向缓慢减少的变化趋势。研究结果可以为盐碱土改良提供重要参考。     

生物质能源与能源林业若干问题研究

概述了生物质能对未来能源发展的重要作用,对我国能源林业和灌木能源林的情况作了简要介绍,并重点提出了小球藻油的利用对生物质能开发的影响.     

沙生灌木纤维基材生产工艺及其应用初探

沙生灌木纤维基材是沙生灌木原料应用的新领域,是治理荒漠的新型植生带.简介植生带的国内外研究进展,介绍沙生灌木纤维基材的原料、生产工艺和优点.     

胡枝子对水土保持作用的研究

通过胡枝子在试验场种植情况的介绍,证明营造胡枝子是对水土保持和固土防冲十分有益的生物防护措施。     

Assessing changes of forest area and shrub encroachment in a mire ecosystem using digital surface models and CIR aerial images

This paper presents an approach to assess increase and decrease (2002–1997) of forest area and other wooded areas in a mire biotope in the Pre-alpine zone of Central Switzerland using logistic regression models and airborne remote sensing data (CIR aerial images, DSM derived from them). The present study was carried out in the framework of the Swiss Mire Protection Program, where increase and decrease of forest areas are key issues. In a first step, automatic DSMs were generated using an image matching approach from CIR aerial images of 1997 and 2002. In a second step, the DSMs were co-registered and normalized using LiDAR data. Tree layers from both years of various levels of detail were then generated combining canopy covers derived from normalized DSMs with a multi-resolution segmentation and a fuzzy classification. On the basis of these tree layers, fractional tree/shrub covers were calculated using explanatory variables derived from these DSMs only. Bias was estimated by analysing the distribution of the fractional model differences. The corrected models reveal a decrease of tree/shrub probability which indicates a decrease of forest and other wooded areas between 1997 and 2002. The models also indicate real shrub encroachment in open mire. The detection of shrub encroachment may be helpful for selective logging purposes for sustainable mire habitat management. The study stresses the importance of high-resolution and high-quality DSMs and highlights the potential of fractional covers for ecological modeling.     

青藏高原东北部黄土区灌木植物根系护坡效应的数值模拟

为研究青藏高原东北部黄土地区灌木植物根系与边坡稳定性之间的关系,以试验区西宁盆地及其周边黄土边坡为例,选取适合于研究区生长的柠条锦鸡儿、四翅滨藜、霸王及白刺4种灌木进行坡面种植,并对其根–土复合体进行力学强度试验,且采用二维有限元法模拟试验区生长期为2a的4种灌木植物根系对边坡稳定性的增强作用。试验和模拟结果表明:试验区种植4种灌木植物的坡体,其水平方向和垂直方向的位移显著小于素土边坡,相比较而言,种植4种灌木植物的坡体所发生的水平和垂直最大位移量相对由小至大的顺序依次为柠条锦鸡儿、四翅滨藜、霸王及白刺;4种灌木植物其侧根和主根在土体中分别起到加筋和锚固作用,这种根–土相互作用增加了坡体的黏聚力和抗剪强度,从而使试验区边坡应力集中范围缩小,塑性破坏区面积减小。试验区边坡安全系数计算结果表明,与素土边坡相比,试验区四翅滨藜、柠条锦鸡儿、霸王、白刺根–土复合体边坡相对稳定安全系数依次增强80.5%,48.7%,22.1%和8.0%。由此说明试验区4种灌木植物其护坡贡献大小依次为柠条锦鸡儿、四翅滨藜、霸王及白刺。研究成果可作为青藏高原东北部黄土区采用优势护坡灌木植物,防治坡面浅层滑坡、崩塌、泥石流等地质灾害发生的理想依据之一。     

Bio-oil production via fast pyrolysis of shrub residues in a fluidized-bed reactor

In this article, the shrub residues as raw materials were produced to fast pyrolysis oil (called bio-oil) in a 5-kg/h fluidized-bed reactor. The optimum conditions were obtained at 500°C, flow rate of fluidizing gas of 4 m³/h, and feed rate of 3 kg/h. The liquid yield was up to 60% at the optimum conditions. The bio-oil was easy to divide into two phases: oil phase and aqueous phase. The high heat value of the oil phase was up to 18.55 MJ/kg, but the high heat value of the aqueous phase was only 0.72 MJ/kg. The oil phase and aqueous phase both have lower pH values. The oxygen content was up to 50%, while the sulfur and nitrogen content were very low. Owing to the higher oxygen content and lower pH value in liquid products, it must be further upgraded to bio-oil before application.     

我国非木材人造板的发展现状和存在问题

介绍我国农业剩余物秸秆人造板、竹材人造板和沙生灌木人造板等非木材人造板的发展现状及非木材人造板发展过程中存在的问题。     

Mapping shrub abundance in desert grasslands using geometric-optical modeling and multi-angle remote sensing with CHRIS/Proba

This work examines the application of a geometric-optical canopy reflectance model to provide measures of woody shrub abundance in desert grasslands at the landscape scale. The approach is through inversion of the non-linear simple geometric model (SGM) against 631 nm multi-angle reflectance data from the Compact High Resolution Imaging Spectrometer (CHRIS) flown on the European Space Agency's Project for On-Board Autonomy (Proba) satellite. Separation of background and upper canopy contributions was effected by a linear scaling of the parameters of the Walthall bidirectional reflectance distribution function model with the weights of a kernel-driven model. The relationship was calibrated against a small number of sample locations with highly contrasting background/upper canopy configurations, before application over an area of about 25 km². The results show that with some assumptions, the multi-angle remote sensing signal from CHRIS/Proba can be explained in terms of a combined soil-understory background response and woody shrub cover and exploited to map this important structural attribute of desert grasslands.     

Effects of several factors on plant calorific value based on large-scale conditions

热值作为植物的重要属性,具有一定的稳定性,是衡量植物第一性生产力、植物营养价值的重要参考指标,也是生态系统研究过程的重要参数之一。然而在热值的研究过程中,人们往往针对某种植物,或者某地区的某些植物来展开研究,很少在大尺度上对植物热值进行系统的研究。本研究搜集1989―2010年维普《中文期刊数据库》（http：//www.cqvip.com）中公开发表的相关研究论文,对39个样地的547种植物的热值进行归类总结,在大尺度上探讨植物器官、科、生活型及经纬度对热值的影响。结果表明,不同生活型植物热值的顺序为乔木〉灌木〉草本,并且这种变化趋势不因植物种类和植物分布地区的变化而变化;草本与灌木植物叶片的热值最高、根系最低,而乔木则以枝条最高、根系最低;以草本和灌木植物为主的科,其热值要低于以乔木为主要组成的科,本研究所涉及的各科植物以藜科植物热值最低,杜鹃花科最高;植物的热值随着纬度的增加而升高。