生态经济区建设分析

对现有生态经济区理论和实践的梳理,认为促使生态经济区建设的充分、必然条件是自然的可能性、经济的可行性、政策的可容性和民众的选择性。现实中,自然的可能性和政策的可容性是生态经济区建设的主要驱动力;而经济发展和民众需求不充分是生态经济区建设的限制性因素。环境外部性强与生态环境脆弱、处在重要经济区内与自身经济发展水平低、政策约束性强与政策可操作性弱、城乡二元性与民众需求不一致是四个因素中的主要矛盾方面。矛盾的根源在于选择的经济发展模式与当地所处的生产力发展阶段不相适应。破解矛盾的主要办法是加快发展生产力,而加快发展的必要条件是有重要经济区支持。     

小兴安岭退化沼泽湿地植被恢复技术

以黑龙江省友好国家级自然保护区火烧、放牧和垦殖3 种干扰类型退化森林沼泽湿地为研究对象,应用样地 调查法和挖掘法对植物生长指标进行调查,分析不同栽植模式对退化沼泽湿地植被的恢复效果。结果表明:在火 烧干扰湿地中,栽植红皮云杉纯林是最好的植被恢复模式,栽植3 年成活率为89%,其他植被恢复模式的树木成活 率都很低。在放牧干扰湿地中,红皮云杉纯林、落叶松纯林模式和红皮云杉与落叶松混交林的造林模式恢复效果 好,3 年平均成活率分别为94%、79%、85.5%。在垦殖干扰湿地中,栽植红皮云杉、落叶松纯林模式或红皮云杉与 落叶松混交林的造林模式恢复效果好,3 年平均成活率分别为92%、85%、83%。沙棘在3 种退化森林湿地中3 年 成活率均低于36%,不适合在以上的退化湿地中进行培植。因此,在小兴安岭干扰火烧退化湿地、放牧退化湿地以 及垦殖退化湿地植被恢复中,应选择以红皮云杉、落叶松为主的恢复树种。      

厚壁毛竹结构性成分含量特征

采用范氏洗涤纤维法分别测定竹叶、竹枝和竹秆中的纤维素、半纤维素和木质素的含量,研究了厚壁毛竹不同部位和不同生长时间的结构性成分含量变化特征。结果表明：竹叶中纤维素含量低于半纤维素含量[分别为（27．71±5．82）％、（38．02±5．76）％],而竹枝和竹秆中纤维素含量均明显高于半纤维素含量;各部位按纤维素含量、木质素含量和结构性成分含量总和的高低分别为：竹秆中部、竹秆基部、竹秆梢部、竹枝和竹叶,而半纤维素含量相反。方差分析表明,不同部位间的纤维素、半纤维、木质素含量及其总和的差异均达到极显著水平（ F＞F0．01,P＜0．01）;不同生长时间的结构性成分含量及其总和的差异相对较小,仅木质素含量的差异达到显著性水平（ F＝4．777,P＝0．012）。研究结果为厚壁毛竹的利用奠定基础。     

组合栽培对 I－107欧美杨树生长及根际土壤特性的影响1）

以6年生I－107欧美杨为试材,研究了CK（对照,习惯施肥）、T1（断根＋习惯施肥）、T2（断根＋有机肥）、T3（断根＋有机肥＋覆膜）和T4（断根＋有机肥＋覆膜＋灌溉）等不同措施对杨树生长及根际土壤学特征的影响。结果表明：与CK相比,T4处理明显增加了根际土壤中细菌数、真菌数、微生物总量及微生物量碳、氮质量分数,其中微生物量碳、氮质量分数分别增加190．02％和134．64％;还显著提高了根际土壤中脲酶、过氧化氢酶、多酚氧化酶、蔗糖酶活性及有机碳、活性有机碳、碱解氮、速效磷、速效钾质量分数和土壤电导率值,但明显降低了pH值。在4种组合措施中,以T4处理的胸径、树高和材积生长率最高,分别较CK提高77．42％、113．94％和83．17％。同T4处理相比,T1、T2和T3处理对杨树生长及根际土壤特性的影响作用较小。综合分析认为,断根、有机肥、覆膜和灌溉等措施的协同作用对I－107欧美杨生长的应用效果最佳。     

大兴安岭用材林不同强度采伐后土壤模糊聚类分析1）

在大兴安岭用材林建立20个不同采伐强度的样地,然后采集样地的土壤并对其理化性质进行测定,以土壤pH 、有机质、全氮、全磷、全钾、水解氮、有效磷、速效钾、密度、含水率、最大持水量、毛管持水量、毛管孔隙度、非毛管孔隙度等14个土壤理化因子作为分类指标,采用模糊聚类分析法对20个样地的土壤进行分类,再用F－统计量确定最佳阈值（λ）。结果表明：当阈值λ为0．8483时,20个样地的土壤被分为3类,此种分类较为合理,分类结果与实际情况比较相符。其中：第一类土壤的有机质和全氮质量分数较低,土壤物理性质较差;第二类土壤的全磷和全钾质量分数较低,土壤物理性质较好;第三类土壤的有效磷和速效钾质量分数较低。采用模糊聚类分析法,对大兴安岭不同强度采伐后的样地土壤进行分类行之有效。     

大兴安岭5种类型低质林土壤呼吸日变化及影响因素

以大兴安岭地区针阔混交低质林、山杨低质林、蒙古栎低质林、白桦低质林、阔叶混交低质林为研究对象,采用LI-8150多通道土壤呼吸自动测量系统测定了不同类型低质林土壤呼吸速率的日变化,并测定了观测点的土壤温度、湿度、理化性质以及枯落物。结果表明：不同类型低质林土壤呼吸速率差异显著,土壤呼吸速率白天均高于夜晚,1 d中最高值出现在12：00-14：00,最低值出现在23：00-03：00,土壤呼吸速率与土壤温度的关系适合指数模型（R2为0．73～0．82）,土壤呼吸速率与土壤温度和土壤湿度呈显著的二次曲线关系（R2为0．61～0．85）,土壤温湿度双因子复合模型能更好解释不同类型低质林土壤呼吸速率的差异。土壤呼吸速率与土壤总孔隙度、有机质质量分数存在显著的正相关性,与土壤pH值、氮质量分数及半分解枯落物蓄积量相关性也较高。     

Children's perspectives on vegetation establishment: Implications for school ground greening

School ground greening might provide multiple benefits for children across age, gender and competence through allowing participation in the greening process and experience of nature and vegetation. However, the process of school ground greening must nurture a positive relationship between children and newly planted vegetation during the first years after establishment. This study explored how green space planning, management and maintenance approaches influence children's school ground use and experiences through a series of field observations following establishment of new vegetation in a landscaped area at a school in Malmö, Sweden. The methods included documentation of vegetation, observations of use and interviews with children and teachers on three occasions during one and a half years following the first planting. The greening approach appeared successful, especially for younger children (up to around 11 years), who were more positive and also used the area more than older children. They also used it for pretend play, which was rare in the school ground before greening. Experiences from continuous participation and physical use appeared important for children establishing a positive and caring relationship with the landscaped area. The results suggest that school ground greening should be well integrated with pedagogic activities. Damage to woody vegetation can be limited by establishing other landscape elements that are attractive for play and by using fences without hindering access.     

Effects of off‐bottom shellfish aquaculture on winter habitat use by molluscivorous sea ducks

• 1. Shellfish farming is an expanding segment of marine aquaculture, but environmental effects of this industry are only beginning to be considered.
• 2. The interaction between off‐bottom, suspended oyster farming and wintering sea ducks in coastal British Columbia was studied. Specifically, the habitat use of surf scoters (Melanitta perspicillata) and Barrow's goldeneyes (Bucephala islandica), the most abundant sea duck species in the study area, was evaluated in relation to natural environmental attributes and shellfish aquaculture.
• 3. The extent of shellfish farming was the best‐supported habitat variable explaining variation in surf scoter densities, and the only habitat attribute from the considered set that was a strong predictor of Barrow's goldeneye densities. In both cases, the findings indicated strong positive relationships between densities of sea ducks and shellfish aquaculture operations. These relationships are presumably the result of large numbers of wild mussels (Mytilus trossulus) that settle and grow on aquaculture structures and are preferred prey of these sea ducks.
• 4. Previous work has shown that aquaculture structures provide good conditions for recruiting and growing mussels, including refuge from invertebrate predators, which in turn provides higher densities of higher quality prey for sea ducks than available in intertidal areas. This offers a rare example in which introduction of an industry leads to positive effects on wildlife populations, which is particularly important given persistent declines in numbers of many sea ducks.

Copyright © 2008 John Wiley & Sons, Ltd.     

俄罗斯鲟（Acipenser galdenstadti）规模化养殖研究——Ⅱ.幼鱼驯化技术

本文对俄罗斯鲟（Acipenser galdenstadti)在规模化养殖生产中的幼鱼驯化方法进行比较研究。用活铒开口后，用三种不同方法进行配合饲料驯化度试验，A组用配合饲料直接驯化，B组用饲料和活铒交替投喂，C组（对照组）用活铒投喂。实验结果：A组成活率达到建85.3%，铒料系数为1.59，平均日增重率3%；B组成活率达到93.4%，铒料系数为1.47，平均日增重率3.41%，结果表明，B组交替投喂的效果比A组直接驯化的效果为佳。     

降香黄檀木材DNA提取及rDNA-ITS序列条形码分子鉴定

以不同产地人工林中采取的降香黄檀(Dalbergia odorifera T.Chen)木材为研究对象,提取并扩增不同温度处理后的降香黄檀心、边材DNA和ITS片段,分析不同温度处理对降香黄檀木材DNA提取和PCR扩增的影响;对不同产地的降香黄檀木材及其近缘种多裂黄檀(Dalbergia rimosa Roxb)木材的rDNA-ITS序列进行测定和差异分析。结果表明,25℃和65℃热处理后的木材DNA呈不同程度的弥散分布,105℃热处理后的木材DNA降解成250bp以下的小片段;不同温度处理后的降香黄檀木材,仅有25℃处理后的木材ITS片段能够被成功地扩增。降香黄檀和多裂黄檀ITS序列共存在6个变异位点且ITS2区变异大于ITS1区,聚类分析结果可以将降香黄檀及其近缘种多裂黄檀木材区分开来,为利用ITS条形码序列鉴定降香黄檀木材及其常见混伪品提供理论依据。