资源选择函数拟合藏狐洞穴生境利用特征的有效性分析

资源选择函数(resourceselectionfunctions,RSFs)在分析野生动物栖息地特征以及预测有效生境等方面得到了广泛的运用,但是由于RSFs的理论基础的局限,使得该模型一直以来在研究低密度野生动物种群时的有效性存在很大的争议。藏狐(Vulpesferrilata)是一种低密度物种,我们通过对2001–2003年获得的133个藏狐洞穴样方和随机选取的133个环境样方拟合资源选择函数模型,并将模型结果和主成分分析(PCA)结果进行对比。结果显示RSFs在水源距离、鼠兔洞穴数量、坡向、坡度、坡位和植被类型等6个生境变量中,只对坡向、坡位和植被类型3个变量敏感且总预测率为75.2%,复相关系数为0.485(NagelkerkeR=0.235),同时3个变量的偏相关系数水平也很低。偏差分析(Akaike’sinformationcriterion,AIC)值为309.172,说明模型的预测偏差较大,判别效果不佳,不能有效提炼藏狐洞穴生境的特征因素。而PCA结果显示诸变量的重要性由高到低依次为:鼠兔洞穴数量、水源距离、坡度、坡位、植被类型和坡向,坡向的重要性最弱。我们还着重讨论了RSFs的理论基础和该模型在藏狐洞穴生境中失拟的原因,同时强调为了能对野生动物的生境特征进行比较全面的分析,应该综合多种方法。     

内蒙古东部草原地区赤狐繁殖期对洞穴的选择

通过对内蒙古东部草原地区赤狐的２５个洞穴观测,运用系统聚类分析的方法,研究了赤狐繁殖期的洞穴选择。结果表明,影响赤狐繁殖期洞穴选择的主要因子是水源,其次是坡向、坡位和坡度,人为干扰、隐蔽程度及洞口朝向等因子对其影响作用不明显。繁殖期赤狐的最适洞穴选择为：阳坡或半阴半阳坡、下坡位、坡度５°～２５°、距水源５００～１０００ｍ。     

内蒙古东部草原沙狐春季洞穴选择

通过对内蒙古东部草原64个沙狐洞穴的观测,采用主成分分析法,对沙狐洞穴选择作了初步的定量研究。分析结果表明：影响沙狐春季洞穴选择的主要生态因子有7种,依次为：坡位因子（随坡度,坡高的变化而变化）,水源因子,植被因子,微气候因子,食物因子,人为干扰因子和微生境因子,而坡向,洞口朝向及洞道口倾角等影响不明显。     

贺兰山区马鹿对冬季生境的选择性

2003年11—12月,在贺兰山采用样带法对马鹿阿拉善亚种的生境选择性做了研究。在选定的25条样带上一共测定了87个利用样方以及50个任意样方的14种生态因子(植被类型、优势乔木、坡向、坡位、食物丰富度、乔木密度、灌木密度、坡度、海拔高度、雪深、水源距离、人为干扰距离、裸岩距离和隐蔽级)。结果表明,马鹿对4种生态因子有选择性：①植被类型：偏好利用山地草原带和山地针叶林带,避免选择亚高山灌丛和草甸带;②优势乔木：偏好利用混合型的生境,避免选择杜松、油松和无树的生境;③坡向：偏好位于阳坡的生境,避免利用阴坡;④坡位：偏好位于下坡位的生境,避免选择上坡位和中坡位。对利用样方和任意样方进行比较,发现马鹿的利用样方以灌木密度高、食物丰富、坡度小、接近水源、雪覆盖浅、远离裸岩和人为干扰为主要特征。对各种生态因子的主成分分析表明前6个主成分的累积贡献率已经达到了84．89％,可以较好地反映马鹿的生境特征。第1主成分反映出马鹿在选择生态因子方面与植被类型、乔木密度、灌木密度、坡向、坡度、距水源距离、雪深、海拔高度正相关。     

察青松多白唇鹿国家级自然保护区白唇鹿对夏季生境的选择

白唇鹿是青藏高原特有鹿种,人们对其生境选择与利用知之甚少。2009年6-8月和2011年7-8月,用痕迹检验法和直接观察法研究了察青松多白唇鹿国家级自然保护区内白唇鹿的夏季生境选择。在保护区内若当沟和麻绒沟两个白唇鹿集中分布区域测定了195个样方中的植被类型、海拔高度、坡位、坡度、坡向、离水源距离、隐蔽度和人类活动干扰8个生态因子。用Vanderloeg和Scavia选择指数和主成分分析法分析了白唇鹿夏季生境选择的影响因子。结果表明:白唇鹿夏季倾向于选择海拔4 000 m以上中上坡位的高山草甸生境和离水源距离500 m以外的阳坡或阴坡生境;而回避坡度大于60度、裸岩生境、下坡位生境和半阴坡生境。除隐蔽条件和人类活动干扰外,其余6个生态因子均对白唇鹿夏季生境选择有明显的影响。生态因子主成分分析表明前3个主成分的贡献量为68.8%,其中:第1主成分的贡献率为39.76%,该主成分与坡位、坡度和海拔的相关系数绝对值较大;第二主成分的贡献率为16.32%,与其相关系数绝对值较高的是隐蔽条件与植被类型;第三主成分的贡献率为12.71%,与其相关系数绝对值较高的是坡向。     

大兴安岭原麝冬季的生境选择

2005年3～4月和2006年3月,在黑龙江省大兴安岭呼中自然保护区,采用机械布点法随机设置样线,对原麝(Moschus moschiferus)冬季生境选择进行了研究。对海拔、乔木密度、雪深、隐蔽度、食物丰富度、坡度和倒木数量进行2个独立样本的Mann-Whitey U检验,找出生境利用样方与任意样方的生态因子的差异。U检验的结果表明,原麝冬季喜欢活动在相对海拔高、乔木密度小、雪层浅、隐蔽度高、坡度陡且喜食食物丰富的区域;对植被类型、坡位、坡向、距水源距离、距人为干扰距离、动物干扰和碎石坡7个名词性变量采用卡方(Chi-square)统计进行显著性检验,卡方检验的结果表明:原麝冬季偏好远离人为干扰、接近碎石坡、阳坡和其他动物干扰较少的针阔混交林中;对以上14个生态因子进行主成分分析,结果表明,前6个特征值的累计贡献率达到72·318%,可以较好地反映原麝生境特征,根据主成分分析结果,将原麝冬季生境选择影响因子分别命名为空间因子(海拔、坡度、距碎石坡距离)、干扰因子(距人为干扰距离、距水源距离)、坡向因子(坡向、乔木密度)、坡位因子(坡位、动物干扰)、食物因子(食物丰富度、隐蔽度)和倒木因子(倒木数量)。     

黄泥河自然保护区野猪冬季栖息地利用

2009年11月-2010年1月,根据野猪的生物学特征和黄泥河自然保护区的地形、地貌特点,在研究地区布设47条样线,对保护区的野猪冬季栖息地利用进行了研究,测定了野猪对海拔、坡位、坡向、坡度、植被类型、郁闭度、树高度、树胸径、食物丰富度、隐蔽度、离水源距离和离人为干扰距离等12种生态因子的选择利用情况.结果表明:黄泥河自然保护区野猪冬季多活动在海拔≤1000 m,坡下位的阳坡平坦地带,食物丰富度高,隐蔽度强,郁闭度中等,且离水源≤500 m,离人为干扰>2000 m的阔叶林和针阔混交林内;主成分分析表明,栖息地变量前4个特征值的累积贡献率达到77.5%,较好地反应了野猪的栖息地特征;影响野猪栖息地选择的关键因子是海拔、坡度、离人为干扰距离,次要因子是离水源距离、隐蔽度、树胸径.     

张广才岭藏獾洞穴生境选择

2008年9月至2009年8月,在黑龙江省方正林业局新风林场,用不定宽样线法对藏獾洞穴生境选择进行研究,共记录了55组藏獾洞穴,藏獾洞口平均直径为(27.40±7.15)cm,洞深平均为(84.18±22.04)cm,倾角平均为(26.36±9.10)°,洞口总数=3.02个常用洞数+0.80个不常用洞数+0.56个废弃洞数。相对于对照样方而言,藏獾洞穴更偏爱选择位于郁闭度和植被盖度小,灌木密度大、距离近,乔木距离远,距水源和农田近、人为干扰距离远,坡度较缓的向阳中坡位的生境。资源选择函数模型为:logit(p)=246.980-1.059×植被盖度-0.703×距水源距离-1.403×坡度-45.005×坡向,模型的正确预测率为93.9%。     

河南伏牛山北坡果子狸夏季巢穴生境特征

通过对伏牛山北坡果子狸夏季巢穴生境选择的研究,以海拔、植被类型、坡度、坡向、坡位、巢穴隐蔽程度、水源距离、干扰距离、郁闭度、乔木距离、灌木距离、灌木密度12个指标进行评估。分析结果表明,果子狸夏季巢穴生境的选择特征是:(1)地理分布因子:海拔900-1200m地带,以阔叶林为主,杂有少量针阔混交林。(2)干扰因子:距离人类活动较近的地方。(3)隐蔽因子:郁闭度高、灌木密度高、隐蔽程度好的巢穴。(4)地形因子:巢穴位于斜坡或陡坡的上坡位或中坡位的阳坡或半阳坡。(5)食物丰富度因子:巢穴选择在乔木个体发育较好的阔叶林中,有丰富的食物来源。(6)水源因子:水源距离在100m以内。     

伏牛山北坡猪獾(Arctonyx collaris)夏季巢穴特征

2005年7月和8月在伏牛山北坡调查猪獾巢穴共43个,对巢穴的海拔、植被类型、坡度、坡向、坡位、巢穴隐蔽程度、水源距离、干扰距离、郁闭度、洞口隐蔽程度、洞口数量、巢穴类型、乔木距离、灌木距离、灌木密度、倒木等16个指标进行评估.分析结果表明,伏牛山北坡猪獾夏季巢穴的选择特征是:(1)隐蔽因子,选择在巢穴和洞口的隐蔽程度、郁闭度均较高的阔叶林中;灌木密度高,乔木距离为75～150 cm.(2)地理因子,选择在海拔为900 ～1200 m的阳坡或半阳坡上,以1个洞口的石洞为主.(3)干扰因子,没有倒木,距离人类活动村落地点较近.(4)水源因子,水源距离在100 m以内.     

Numerical approaches towards life cycle interpretation five examples

The ISO-standard for LCA distinguishes four phases, of which the last one, the interpretation, is the least elaborated. It can be regarded as containing procedural steps (like a completeness check) as well as numerical steps (like a sensitivity check). This paper provides five examples of techniques that can be used for the numerical steps. These are the contribution analysis, the perturbation analysis, the uncertainty analysis, the comparative analysis, and the discernibility analysis. All five techniques are described at a non-technical level with respect to basic concept, possibilities, tabular and graphical representation, restriction and warnings, and all are illustrated with a simple example.     

影响水稻光合日变化的酶和相关因素的分析

水稻叶片的最大光合速率出现在上午１０：００时,Ｒｕｂｉｓｃｏ初始活力也在此时达到最大,然后逐渐降低,下午１４：００时略上升后又下降．Ｒｕｂｉｓｃｏ初始活力与光合速率之间极显著相关,相关系数为 ０．９４７４．运用相关性分析、回归分析、通径分析,对晴（有时有云）天气水稻叶片的光合速度、光合关键酶及有关因素的日变化进行综合评估,结果发现中午光合下降主要来自气孔限制,同时Ｒｕｂｉｓｃｏ活性也下降;Ｒｕｂｉｓｃｏ活性是影响光合日变化的又一重要生化因子．体内Ｒｕｂｉｓｃｏ活性受Ｒｕｂｉｓｃｏ活化酶的调节．     

Discrimination of higher plant calluses based on embryogenic capacity and taxonomic classification by pyrolysis mass spectrometry

Pyrolysis mass spectrometry (PyMS) is a rapid, simple, high-resolution analytical method based on thermal degradation of complex material in a vacuum, and has been widely applied to the discrimination of closely related microbial strains. Minimally prepared samples of embryogenic and non-embryogenic calluses derived from various higher plants (sweet potato, morning glory, Korean ginseng, Siberian ginseng, and balloon flower) were subjected to PyMS for spectral fingerprinting. A dendrogram based on the unweighted pair group method, with arithmetic mean of pyrolysis mass spectra, divided the calluses into Siberian ginseng embryogenic callus and the others, which were subsequently divided into embryogenic and non-embryogenic callus groups, regardless of plant species from which the calluses were derived. In the non-embryogenic callus group, the dendrogram was in agreement with the known taxonomy of the plants. These results indicate that PyMS analysis could be applied for discriminating plant calluses based on embryogenic capacity and taxonomic classification.     

Intraspecific variation in Licuala glabra Griff. (Palmae) in Peninsular Malaysia– a morphometric analysis

We studied vegetative and reproductive characters of 74 herbarium specimens of Licuala glabra Griff. (Palmae) collected from 22 localities throughout Peninsular Malaysia. To test the null hypothesis that there are no distinct groups within the species, cluster analysis (nearest neighbour), principal coordinates and principal components analyses were performed on the set of 43 qualitative and quantitative characters. The results obtained suggested that: (1) there are three infraspeciflc groups within the species, viz., the two published varieties glabra and selangorensis as well as a possible third novel taxon; (2) there is clustering of individuals corresponding to their geographic localities; (3) clusters generated using only reproductive characters indicate a biogeographic distribution of populations correlated with the mountain ranges in the peninsula.     

Fish ecoregions of Kansas: stream fish assemblage patterns and associated environmental correlates

Synopsis Principal components analysis was performed on fish presence/absence data for 39 common fish species from 410 stream sites in Kansas. The analysis confirmed ten ecologically meaningful fish assemblages, based on species associations. Factor scores based on these assemblages were then clustered into six geographic areas or fish ecoregions. Canonical discriminant analysis identified environmental variables that distinguished the derived fish ecoregions. Mean annual runoff, mean annual growing season, and discharge appear most important. Mean width, mean depth, chloride concentration, water temperature, substrate type, gradient, and percent of pool habitat were less important. Correspondence exists between these fish ecoregions and the patterns of physiographic regions, river basins, geology, soil, and potential natural vegetation in Kansas. The multivariate statistical approach used to classify fish ecoregions should have considerable potential value for fish assessment and management purposes in areas other than the state of Kansas.     

Some remarks about the analysis of active control studies

In an active-controlled trial, the experimental treatment can be declared to be non-inferior to the control if the confidence interval for the difference excludes a fixed pre-specified margin. Recently, some articles have discussed an alternative method where the data from the current study and placebo-controlled studies for the active control are combined together into a single test statistic to test whether a fixed fraction of the effect of the active control is preserved. It has been shown that, conditional on nuisance parameters from the active-controlled study, a fixed margin can be defined that will be operationally equivalent to this latter method. In this article, we will discuss statistical properties associated with these approaches. Specifically, the interim monitoring boundaries and level of evidence will be considered.     

Normal Approximations of Exact Tests in Configural Frequency Analysis

The most common tests for types and antitypes in configural frequency analysis are normal approximations of exact tests. In the paper such statistics under the complete independence model and under the fixed margins model are discussed. It turns out that these test statistics are not acceptable when the number of simultaneously performed tests is large or when the expected frequencies are small. In these cases, the use of exact tests is advocated and some existing computer programs for such tests are indicated. A normal approximation based on the strong version of the De Moivre-Laplace limit theorem is also discussed. Empirical examples are given from longitudinal data describing psychological development of boys.     

Phenotypic evaluation of genetic variability and selection of yield contributing traits in chickpea recombinant inbred line population under high temperature stress

Heat is a major abiotic stress that drastically reduces chickpea yield. This study aimed to identify heat-responsive traits to sustain crop productivity by screening a recombinant inbred line (RILs) population at two locations in India (Ludhiana and Faridkot). The RIL population was derived from an inter-specific cross between heat-tolerant genotype GPF 2 (C. arietinum L.) and heat sensitive accession ILWC 292 (C. reticulatum). The pooled analysis of variance showed highly significant differences for all the traits in RILs and most of the traits were significantly affected by heat stress at both locations. High values of genotypic coefficient of variation (19.52–38.53%), phenotypic coefficient of variation (20.29–39.85%), heritability (92.50–93.90%), and genetic advance as a percentage of mean (38.68–76.74%) have been observed for plant height, number of pods per plant, biomass, yield, and hundred seed weight across the heat stress environments. Association studies and principal component analysis showed a significant positive correlation of plant height, number of pods per plant, biomass, hundred seed weight, harvest index, relative leaf water content, and pollen viability with yield under both timely-sown and late-sown conditions. Path analysis revealed that biomass followed by harvest index was the major contributor to yield among the environments. Both step-wise and multiple regression analyses concluded that number of pods per plant, biomass and harvest index consistently showed high level of contribution to the total variation in yield under both timely-sown and late-sown conditions. Thus, the holistic approach of these analyses illustrated that the promising traits provide a framework for developing heat-tolerant cultivars in chickpea.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12298-021-00977-5.     

分子水平的遗传多样性及其测量方法

遗传多样性水平是一项很重要的数据。目前从分子水平量化遗传多样性的方法以等位酶分析、ＲＦＬＰ分析和ＲＡＰＤ分析为代表。遗传变异在基因组中并非随机分布,所以取样方式对分析结果的影响不容忽视。本文叙述了遗传变异的产生和分布,并以此为基础比较了上述３种分析方法的理论与实践。     

凡纳滨对虾各月龄性状的主成分与判别分析

为了研究凡纳滨对虾各性状增长规律和判定最佳生长季节凡纳滨对虾的体格与月龄的关系,选择1～6月龄凡纳滨对虾各1000只,选择全长、体长、第一腹节背高、第三腹节背高、第一腹节背宽、头胸甲长和体重共7个性状,进行主成分与判别分析.结果表明:各月龄凡纳滨对虾性状之间均呈现显著的正相关(P<0.01), 其中以全长与体长的相关性最为明显,1月龄凡纳滨对虾体重与形态性状的相关系数较小.各月龄凡纳滨对虾的主成分有所不同,1～2月龄凡纳滨对虾的第一主成分为长度因子,第二主成分为宽度因子,第三主成分为高度因子;3月龄凡纳滨对虾的第一主成分与1～2月龄凡纳滨对虾一致,但第二主成分为高度因子,第三主成分为体重因子;4～6月龄凡纳滨对虾的第一主成分为体重因子,第二主成分为高度因子,第三主成分为宽度因子.1～3月龄凡纳滨对虾形态性状的增长优先于体重, 4～6月龄凡纳滨对虾体重优先于形态性状的增长.错过最佳生长季节的凡纳滨对虾的与体格大小相符的月龄可通过建立的判别式来判断,总的判别准确率为98.98%,其中2～4月龄凡纳滨对虾的判别准确率为100%.