中国生态保护和建设的机制转型及科技需求

近年来,我国生态保护和建设正处于机制转型时期。主要原因是快速的城镇化及其所伴随的农业劳动力析出,农业生产要素中劳动力价格上升而土地价格下降,造成生态治理产品的私人物品属性不断弱化,公共物品属性不断强化。这就意味着生态保护和建设的投入主体应由农牧民转向以政府所代表的全社会;策略上由"改善土地生产条件、以开发带动治理"向"保护为主、监督开发"转变;措施取向上从"主动干预自然"向"依靠大自然自我恢复能力"转变。这一转型也要求生态保护和建设的科技工作重点实现相应调整:从以往侧重减缓生态压力的间接治理模式和技术开发,向直接针对生态系统恢复的科研方向转移。科技攻关的重点应为生态系统结构和功能的监测、生态服务功能的评估及生态建设规划等方面。     

Evaluation of major Acacia species in the nursery towards apicultural landscape restoration around Southwestern Saudi Arabia

Southwestern Saudi Arabia is described by a unique ecosystem and composed of apicultural landscapes where nearly 70% of the beekeeping activities are concentrated. However, this economically important resource is under continuous degradation threat urging restoration. Besides, profound information on the possible major biological components of future restoration; nursery level performances of the native plants, Acacia species is lacking. Hence, the study was aimed at evaluating performances of selected native Acacia species at nursery level as candidate biological tool for apicultural landscape restoration. For this, nine native Acacia species’ seedlings were prepared in accordance to appropriate techniques of nursery operations recommended for arid areas. Meanwhile, species were evaluated and compared based on some performance parameters. Accordingly, significant (P < 0.005) variations were observed among the species in shoot height, collar diameter, height to collar diameter ratio, number of leaves and seedling survival. Acacia origena Hunde, A. gerrardii Benth., and A. johnwoodii Boulos. were superior over the others in most parameters while A. etbaica Schiweinf. and A. asak (Forssk.) willd. were less vulnerable to chanced pathogens. Generally, nursery level performances of all Acacia species under experimentation were within the acceptable range and showed a remarkable score which may lead them to be considered as competent biological tools in the incorporation of the genotypes in apicultural landscape restoration efforts.     

辽宁建平古人类肱骨形态结构分析

1957年,在辽宁省建平县发现了一根古人类肱骨化石,编号PA103。通过同一批龙骨中筛选的哺乳动物化石,吴汝康推断PA103应该为更新世晚期古人类,并对该化石进行了表面形态特征观察和描述。为了对PA103化石的内外结构进行更全面的了解,除了线性测量数据的对比,本文还通过计算机断层扫描技术,结合生物力学和形态示量图分析对建平古人类右侧肱骨化石PA103进行了分析。通过本研究发现,PA103骨干横断面的生物力学粗壮度和力学形状指数明显小于尼安德特人,而与同时期欧亚大陆古人类不利手侧最为接近,这说明建平人右侧肱骨可能不是惯用手,同时,建平人的行为活动应该与同时期同地区的古人类处于同一水平,而小于尼安德特人。整体来看,PA103骨干骨密质厚度和截面惯性矩与近现代人的分布模式较为接近,除局部数值增大外,其整体数值小于近现代人的平均水平,这可能与遗传或行为活动有关,由于缺少古人类化石对比数据,更详细的了解还需后期开展更多相关的研究。     

硬头鳟幼鱼部分形态性状和体重的关系

随机选取116尾硬头鳟(Oncorhynchus mykiss)幼鱼,测量其体长、体高、体厚、头长、眼径和眼间距、体重7个性状,计算各性状间的相关系数,采用通径分析方法计算以表型形态性状为自变量对体重作因变量的通径系数、决定系数及复相关指数,对各性状的影响大小进行剖析,明确影响硬头鳟幼鱼体重的主要外部形态性状,为硬头鳟...     

Spatial memory and animal movement

Memory is critical to understanding animal movement but has proven challenging to study. Advances in animal tracking technology, theoretical movement models and cognitive sciences have facilitated research in each of these fields, but also created a need for synthetic examination of the linkages between memory and animal movement. Here, we draw together research from several disciplines to understand the relationship between animal memory and movement processes. First, we frame the problem in terms of the characteristics, costs and benefits of memory as outlined in psychology and neuroscience. Next, we provide an overview of the theories and conceptual frameworks that have emerged from behavioural ecology and animal cognition. Third, we turn to movement ecology and summarise recent, rapid developments in the types and quantities of available movement data, and in the statistical measures applicable to such data. Fourth, we discuss the advantages and interrelationships of diverse modelling approaches that have been used to explore the memory–movement interface. Finally, we outline key research challenges for the memory and movement communities, focusing on data needs and mathematical and computational challenges. We conclude with a roadmap for future work in this area, outlining axes along which focused research should yield rapid progress.     

Molecular and morphometric variation in chromosomally differentiated populations of the grasshopper Sinipta dalmani (Orthopthera: Acrididae)

Sinipta dalmani is an Argentine grasshopper whose chromosome polymorphisms have been widely studied through cytogenetic, morphometric, and fitness component analyses. The present work analysed molecular and morphometric variation in seven chromosomally differentiated populations from Entre Rios and Buenos Aires provinces to analyse population structure. Molecular studies were performed studying RAPD loci and morphometric analyses were carried out measuring five morphometric traits. Genetic variability was high in all studied populations and was characterized by a decrease in H as a function of latitude and temperature. Both conventional F(ST) analysis and Bayesian approach for dominant marker showed that there were significant genetic differences among all populations, between provinces, and among populations within provinces. Entre Rios populations showed higher mean numbers of migrants per generation as well as low genetic differentiation and high gene flow with almost all populations whereas Buenos Aires populations may be considered as a result of a more recently colonization. There is considerable morphometric variation between populations and this variation correlates with latitude and temperature. Our results suggest that selection contributes to phenotypic differentiation among populations by moulding the differences in trait means whereas genetic drift is responsible for differences in the matrix of variance-covariance. The gene flow detected is insufficient to prevent phenotypic and chromosome divergences.     

Morphological analysis of geographic variation of sea lamprey ammocoetes in Portuguese river basins

The main objective of this study was to compare the morphological variability of sea lamprey (Petromyzon marinus L.) larvae from the main Portuguese river basins. Samples were collected in rivers Minho, Lima, Cávado, Vouga, Mondego, Tejo and Guadiana. Specimens were analysed in terms of morphometric (linear body measures) and meristic (number of myomeres) characters to investigate the hypothesis of population fragmentation between river basins caused by some degree of homing behaviour. The discriminant analysis showed a morphological segregation of the studied populations based on the characters head, tail and branchial length. The discriminatory power of the meristic characters was comparatively weaker, with the number of trunk myomeres, and to some extent the head myomeres, being responsible for the reduced separation between groups. Both analyses were consistent in identifying the cephalic region as the most important morphological feature to discriminate populations of sea lamprey larvae in the Portuguese territory. The largest cephalic region of the ammocoetes sampled in the northern river basins may be responsible for a better feeding efficiency and, consequently, higher values of condition factor. Guest editors: S. Dufour, E. Prévost, E. Rochard & P. Williot Fish and diadromy in Europe (ecology, management, conservation)     

动物的易绝灭特征与保护优先性

各种人为干扰和自然因素促使大量物种走向濒危和绝灭。物种濒危和绝灭不是随机的。具有某些特征的物种容易濒危和绝灭 ,即易绝灭特征。易绝灭特征包括个体大 ,繁殖力低 ,扩散能力弱 ,营养级高 ,家域大 ,种群小 ,种群波动大 ,分布范围窄 ,种群密度低 ,栖息地特化程度高和特殊栖息地类型等。研究物种的易绝灭特征可以为生物多样性提供预防性 (proac tive)的优先保护措施。尽管物种的易绝灭特征已经用于实际的物种保护中 ,然而由于物种的各种特征对物种濒危和绝灭的影响十分复杂 ,各个易绝灭特征还有待于进一步深入的、准确的研究。探讨适合不同类群和不同地区物种的易绝灭特征是十分必要的。由于特殊地史发育、中医药传统和边境频繁的非法野生动物贸易 ,我国动物的濒危模式可能与国外有所不同。     

大菱鲆幼鱼表型形态性状与体重之间的关系

随机选取1120尾3月龄大菱鲆幼鱼,测量其体长、全长、体高、头长、吻尖至鳃裂前缘长、尾柄长、尾柄高、体厚、体重等9个性状,计算各性状间的相关系数,采用通径分析方法计算以表型形态性状为自变量对体重作依变量的通径系数、决定系数及复相关指数, 对各性状的影响大小进行剖分,明确影响大菱鲆三月龄幼鱼体重的主要外部形态性状,为大菱鲆选育提供理论依据和理想的测度指标.结果表明:所测各表型性状与体重之间的相关系数均达到极其显著水平(P＜0.01＝;全长对体重的直接影响(R=0.702)最大, 对体重的决定程度(R2=51.84%)最高,是影响体重的主要因素;体高、体厚对体重的直接作用 (0.211 ,0.094)相对较小,主要通过体长的间接作用(0.5558,0.4342)影响体重.所选表型性状对体重的回归系数R2=0.911,表明所选性状是影响体重的主要性状.利用逐步回归分析方法建立以体长、体高、体厚为自变量估计体重的多元回归回归方程为:y=-6.216 1.294x1 0.518x2 1.293x3[动物学报 54(3):540-545,2008].     

子午岭天然林与人工林群落特征比较研究

采用标准样地调查法对比研究了黄土高原子午岭地区人工刺槐林、人工油松林与天然林山杨林、白桦林与辽东栎林的群落特征。结果表明,人工林与天然演替森林（山杨林与自桦林）均具有较丰富的物种组成,为62种左右,而天然顶极森林（辽东栎林）的物种数量则相对较少,为48种。人工林与天然林空间层次分化明显,而且还有一定数量的层间藤本植物。从群落结构的空间格局来看,人工油松林与天然林乔木层与灌木层发育较好,但人工刺槐林的草本层发育较好。人工林的植物多样性主要体现在草本层,而天然林乔木层与灌木层也具有相对较高的多样性。以天然辽东栎林为参照,群落物种组成相似性的比较结果表明,人工刺槐林与天然林的相似性较低,其相似性指数（IS）为19．4,而人工油松林与天然林的相似性则较高,IS值为43．4,甚至高于天然白桦林（33．3）与山杨林（42．9）。因此,相比较而言,油松比刺槐更适合作为黄土高原子午岭地区的人工造林树种。