Cost-effective abundance estimation of rare animals: Testing performance of small-boat surveys for killer whales in British Columbia

Top predators are often rare, subject to anthropogenic mortality, and possess life-history traits that make them inherently vulnerable to extinction. IUCN criteria recognise populations as Critically Endangered when abundance is <250 mature individuals, but estimating abundance of rare species can be more challenging than for common ones. Cost-effective methods are needed to provide robust abundance estimates. In marine environments, small boats are more widely accessible than large ships for researchers conducting sightings surveys with limited funds, but studies are needed into efficacy of small-boat surveys. This study compares line transect and mark-recapture estimates from small-boat surveys in summer 2004 and 2005 for ‘northern resident’ killer whales in British Columbia to true population size, known from censuses conducted by Fisheries and Oceans Canada. The line transect estimate of 195 animals (95% CI 27-559) used model averaging to incorporate uncertainty in the detection function, while the mark-recapture estimate of 239 animals (CI 154-370) used a simple two-sample Chapman estimator. Both methods produced estimates close to the true population size, which numbered 219 animals in 2004 and 235 in 2006, but both suffered from the small sample sizes and violations of some model assumptions that will vex most pilot studies of rare species. Initial abundance estimates from relatively low-cost surveys can be thought of as hypotheses to be tested as new data are collected. For species of conservation concern, any cost-effective attempt to estimate absolute abundance will assist status assessments, as long as estimates are presented with appropriate caveats.     

等值图在测距仪发光管相位测定中的应用

光电测距仪是靠发光管发出的红外光来测定距离的，而以光管本身存在着相位不均匀性，因而使测量的距离存在着误差。本文对此误差用等值相位图描绘出来，从图中不仅能读出误差的大小，而且还能看出相位不均匀性的分布范围，并阐述了消除相位不均匀性的方法     

Variation in sea lice infestation on Atlantic salmon smolts in Killary Harbour,West Coast of Ireland

Approximately 300 salmon smolts were stocked in each of four cages moored at various distances between an Atlantic salmon farm and a river system in Killary Harbour on the West Coast of Ireland. Samples of fish were taken from each of the cages on three occasions and examined for the presence of sea lice (Lepeophtheirus salmonis). Results from one-way ANOVA tests and a multiple comparison of the means of infection levels in the cages indicated that there was a significant difference between the infection levels in the cages on each of the sampling dates. Cage 1, positioned nearest the river, exhibited the highest levels of infection on the first sampling date and was highly significantly different (p 0.001) from the other three cages which showed no significant difference between each other. This situation was again repeated on the second sampling date. On the final sampling date, cage 4, positioned nearest the salmon farm, was highly significantly different (p 0.001) from the other three cages; cage 1 was significantly different (p 0.05) from cages 2 and 3 which showed no significant difference from each other.The population structure of the lice recovered from the smolts indicated that the lice settled in pulses rather than continuously over the trial period. The results are discussed in relation to the hydrography of Killary Harbour, the output of lice larvae from the farm, the impact that these may have on infestations in the inner area of Killary and probable areas of lice larval production.     

新疆塔什库尔干岩羊和北山羊种群密度调查

有蹄类动物为新疆塔什库尔干地区分布的雪豹、狼和猞猁等捕食动物提供了重要的食物资源。为了掌握该地区主要野生有蹄类动物的种群密度,于2009年2～3月通过车行样线和步行样线2种调查方式,采用距离取样方法,对岩羊和北山羊种群数量进行了调查分析。车行样线调查获得的岩羊密度为1.791～6.751只/km~2,北山羊密度为0～0.140只/km~2。步行样线调查获得的密度较低,岩羊和北山羊分别为0.008～0.698只/km~2和0.023～0.252只/km~2。调查结果显示该地区岩羊和北山羊种群密度较上世纪80年代中期有所下降。     

水稻/菰远缘杂交低世代材料遗传变异情况分析

本实验以日本引进粳稻品种松前为受体材料,以水稻的近缘属菰为供体,利用花粉管通道法导入受体水稻菰的基因组DNA。经过两个世代的培养,T1世代表型(株形、穗形、籽粒特征)变异不明显,但统计分析结果表明生育期及有效分蘖数与受体有显著差异。在T2世代发现明显的表型变异株,后代类型丰富,表现为生育期延长、植株高大、分蘖增多、穗长,部分表现为植株矮小、分蘖少,粒形各异有大粒、小粒、长粒,部分表现为带芒,并出现紫粒性状,T2代出现育性分离。     

温室条件下小麦白粉病抗性的综合评价和高抗品种的筛选

为进一步培育高抗白粉病小麦品种提供材料,在温室白粉病高选择压和自然侵染条件下,先后在抽穗期和灌浆期,对80份小麦材料(地方品种、国内育成品种/系、国外引进品种及部分中国春非整倍体材料)的白粉病抗性情况进行调查记载,然后利用马氏距离及其聚类法对不同材料的抗性进行多生育时期和多指标的综合评价。结果表明,国外引进品种Capo全生育期免疫白粉病,中国春衍生的大多非整倍体材料和国外引进品种Coop Capoildo表现高抗。依据各材料间的马氏距离将80份材料分为6类,Capo所在的第2类总体抗性最好,该类包含17份材料,抽穗期和灌浆期平均侵染型小于1.0,平均严重度小于10.0%。中国春及其衍生的非整倍体材料与Capo抗性较为相似,表明中国春携带的广谱抗性基因Lr34仍然具有优异的白粉病抗性。     

株行距配置对宽幅播种小麦产量形成的影响

为探明不同株行距配置对宽幅播种高产栽培下冬小麦产量形成调控的生理基础,选用高产冬小麦品种泰山28为材料,采用裂区设计,主区为种植密度（150×10⁴、225×10⁴和300×10⁴株·hm^-2）,副区为播种行距（25、20和15 cm）,研究了不同株行距配置下小麦干物质积累、转运及产量的影响。结果表明,在150×10⁴株·hm^-2种植密度下,小麦干物质积累量均处于较低水平,产量亦较低;在种植密度225×10⁴株·hm^-2配置20或25 cm行距和种植密度300×10⁴株·hm^-2配置25 cm行距时,小麦干物质积累量和产量均达到较高水平。在种植密度225万株·hm^-2和行距20 cm处理下,小麦开花前营养器官贮藏的同化物向籽粒的转运量、开花后光合产物在籽粒中的积累量及其对籽粒产量的贡献率均显著高于其他处理。泰山28在种植密度225×10⁴株·hm^-2配置20或25 cm行距和种植密度300×10⁴株·hm^-2配置25 cm行距下均可实现三者的协调,获得较高的产量。因此,合理的种植密度和行距配置是实现宽幅播种高产栽培小麦高产的重要技术途径。     

Optimizing thinning and rotation in a stand of Pinus sylvestris on a drained peatland site

A non‐linear programming algorithm was combined with a stand simulator consisting of individual‐tree, distance‐dependent diameter growth, mortality and thinning models, and a distance‐independent height growth model. The Hooke and Jeeves’ direct search method was used for determining the optimum thinning schedule and rotation length. The optimum solutions for both deterministic and stochastic optimization, with stochastic growth predictions, were calculated. In the optimization, stand density was regarded as a function of the distance to ditch. On the rather infertile site, it was most profitable to keep the stand about twice as dense near ditches and the extraction road, which was placed midway between two adjacent ditches. Stochasticity did not affect the optimum regimes markedly nor did it increase the expected returns of the optimum regimes.     

基于 Mahalanobis 矩阵学习的本体算法

提出基于M ahalanobis矩阵学习的本体相似度计算和本体映射算法。利用矩阵分解和坐标下降迭代算法得到M ahalanobis矩阵,进而得到本体图距离矩阵,并由此来判定本体图中2顶点之间的相似程度。最后,将算法应用于生物GO本体和计算机软件本体,通过实验数据验证了算法的有效性。     

实验室条件下鱼类视角与个体邻近距离关系的探究

在麦穗鱼（Pseudorasbora parva）鱼群中,随着邻居鱼的靠拢,其影像在本鱼眼睛中占的视角越大。为了进一步探究其他的鱼群是否也存在相同的规律,本实验选用个体体长较小的喜成群的红鼻剪刀鱼（Hemigrammus rbodostomus）[由30尾组成,平均体长：（20.3±0.2）mm]作为对比研究对象。将其放置在水深5cm的水族缸（78.0cm×52.0cm×65.0cm）中,使用摄像机从正上方拍摄鱼群影像。逐幅提取鱼群影像中各个体的头部、质心（近头部1/3处）、尾部的二维数据,经过数据处理,分析视角与NND间的关系。结果表明：1）红鼻剪刀鱼与麦穗鱼的视角均集中在80o内,即本鱼观察邻居鱼的视角不大于80度。2）在体长差异较大的两种鱼群中,邻近个体占据本鱼的视野范围不会因为鱼体的增大而增加。3）邻近个体占据本鱼视野的最大视角与两者NND间满足以下关系：xy=A,y为视角（用弧度表示）,x为NND（单位:BL）,A为常数。该规律适用于麦穗鱼与红鼻鱼群体。4）该关系式表示,当邻居鱼靠近本鱼时,为了避免碰撞,鱼类个体用视角作为控制的主要参数,调整相互距离;此表明视觉在起主导作用,而侧线,嗅觉、电感觉、磁感觉等即使起作用,也处于次要的地位。