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1.
Predicting the change in abundance is pivotal for evaluating species’ current conservation status and population viability. Empirical works have suggested that species with an increasing abundance have a more aggregated distribution than those with a declining abundance (namely, the change-aggregation hypothesis, CAH). Here we introduced an improved negative binomial distribution model of the occupancy-abundance relationship (OAR) to estimate the change in abundance from changes in occupancy or aggregation. Analysis of the model suggests that (i) in general the change in abundance is synchronized with the change in occupancy when the level of environmental heterogeneity remains constant, and (ii) there could exist a threshold of the population density above which the CAH is no longer valid. Tests using data of epigaeic ants in Fynbos of South Africa collected from different seasons and macro-invertebrates from different localities in streams of central Spain verified these model propositions and thus support the use of this model as a monitoring method for assessing species persistence. Results suggest that the change in abundance can be estimated from the change in occupancy often obtained from cost-efficient presence-absence records, and a revision of the traditional CAH is necessary to capture the threshold phenomenon in the change-aggregation relationship. This work thus signifies the use of the three distinct but related concepts of population structure (i.e. occupancy, abundance and aggregation) in conservation biology.  相似文献   

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Mean sizes of duck hunters’ bags on the opening days of annual waterfowl seasons at selected wetlands in southeastern Australia, between 1972 and 1990, are correlated with an index of the Southern Oscillation (SOI). Simple correlations exist between bag sizes at the various sites, and the mean bag size in Victoria shows a positive relationship with that obtained at Barrenbox Swamp, New South Wales. Bag sizes are most significantly correlated with monthly SOI some 25–28 months before the eventual start of an open season. Interannual variations in rainfall in eastern Australia are generated by the El Niño–Southern Oscillation, which is monitored by the SOI, and the waterfowl populations respond to changing water and wetland availability. Accepting that annual bag sizes represent an index of waterfowl abundance, the regional population size may be related to climatic events associated with changes in SOI values. Further consideration of the SOI and indices of waterfowl abundance may allow variations in legislative or management options well in advance of individual open seasons.  相似文献   

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本文通过对近年在福建各地采集的蝴蝶标本整理鉴定,报道了福建省蝴蝶新记录12种,其中环蝶科1种,眼蝶科3种,蛱蝶科2种,灰蝶科3种,弄蝶科3种。新记录种分别为:白袖箭环蝶Stichophthalma louisa Wood—Mason,边纹黛眼蝶如.the marginolis Motschulsky,细黛眼蝶Lethesidereal Marshall,褐眉眼蝶Mycalesis unicaLeech,中华葩蛱蝶Patsuia sinensis(Oberthur),白斑俳蛱蝶Parasarpa aIbomaculata(Leech),奇娆灰蝶Arhopala comicadleNiceville,小珀灰蝶Pratapa icetas(Hewitson),浙江生灰蝶Sinthusa zhejiangensis Yoshino,梳翅弄蝶Ctenoptilum vasava(Moore),滚边裙弄蝶Tagiades cohaerens(MabiHe)及光荣肿脉弄蝶Zographetus doxusEliot。  相似文献   

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福建省蝴蝶新记录及新订正种   总被引:4,自引:1,他引:3  
本报道福建省新记录及新订正蝴蝶11种,记叙它们的形态特征、采集地、采集生境及采集时间。  相似文献   

6.
In April 2006, a dedicated survey of bowhead whales (Balaena mysticetus) was conducted on the former whaling ground in West Greenland to determine the current wintering population abundance. This effort included a double platform aerial survey design, satellite tracking of the movements of nine whales, and estimation of high-resolution surface time from 14 whales instrumented with time-depth recorders. Bowhead whales were estimated to spend an average of 24% (cv=0.03) of the time at or above 2m depth, the maximum depth at which they can be seen on the trackline. This resulted in a fully corrected abundance estimate of 1229 (95% CI: 495-2939) bowhead whales when the availability factor was applied and sightings missed by observers were corrected. This surprisingly large population estimate is puzzling given that the change in abundance cannot be explained by a recent or rapid growth in population size. One possible explanation is that the population, which demonstrates high age and sex segregation, has recently attained a certain threshold size elsewhere, and a higher abundance of mature females appears on the winter and spring feeding ground in West Greenland. This in combination with the latest severe reduction in sea ice facilitating access to coastal areas might explain the surprising increase in bowhead whale abundance in West Greenland.  相似文献   

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By means of field investigation, specimen identification and related literatures, five species belonging to five genera in three families of angiosperms were identified as new records in Southwest of Guangxi, viz. Whytockia hekouensis Y. Z. Wang, Aeschynanthus chiritoides C. B. Clarke, Petrocodon insliifolius W. H. Chen et Y. M. Shui, Alseodaphne marlipoensis ( H. W. Li) H. W. Li and Cheirostylis malipoensis X. H. Jin et S. C. Chen. Voucher specimens are deposited in Herbarium of Guangxi Institute of Botany ( IBK) .  相似文献   

8.
Lucia Roncaglia 《Grana》2013,52(2):81-88
Anther development, microsporogenesis, and microgametogenesis were studied using both light and TEM microscopy in the six accessible subdioecious/cryptically dioecious species of Consolea (Cactaceae). Anther wall development, microsporogenesis, and microgametogenesis are uniform in staminate flowers of all six species, and are typical for Cactaceae. Breakdown of microsporogenesis in male‐sterile anthers occurs early, at the onset of meiosis, and results in anthers bearing no pollen grains. The abortive process follows a common pattern in all investigated species. The tapetum is the first layer to deviate from normal male‐fertile anther development. Tapetal cells in male‐sterile anthers elongate at an early stage and have abundant rER with atypical configurations. Ultimately, the tapetum becomes hypertrophied and non‐functional. Male‐sterility in pistillate flowers appears to be directly related to these anomalies. In addition, other anther layers and tissues are affected, and normal patterns of programmed cell death (PCD) are disrupted. The relationship between these patterns and the pattern of PCD in normal male‐fertile anthers is discussed. We hypothesize a single origin for the cryptically dioecious/subdioecious breeding system of Consolea based on the uniformity of the anther's abortive processes in pistillate flowers.  相似文献   

9.
Environmental changes are expected to alter both the distribution and the abundance of organisms. A disproportionate amount of past work has focused on distribution only, either documenting historical range shifts or predicting future occurrence patterns. However, simultaneous predictions of abundance and distribution across landscapes would be far more useful. To critically assess which approaches represent advances towards the goal of joint predictions of abundance and distribution, we review recent work on changing distributions and on effects of environmental drivers on single populations. Several methods have been used to predict changing distributions. Some of these can be easily modified to also predict abundance, but others cannot. In parallel, demographers have developed a much better understanding of how changing abiotic and biotic drivers will influence growth rate and abundance in single populations. However, this demographic work has rarely taken a landscape perspective and has largely ignored the effects of intraspecific density. We advocate a synthetic approach in which population models accounting for both density dependence and effects of environmental drivers are used to make integrated predictions of equilibrium abundance and distribution across entire landscapes. Such predictions would constitute an important step forward in assessing the ecological consequences of environmental changes.  相似文献   

10.
Cercosporoid hyphomycetes on living leaves of plants were collected in Panama, identified, described, and illustrated. Newly described species are Passalora guraniae from Gurania sp. (Cucurbitaceae), Pseudocercospora arrabidaeae from Arrabidaea cf. candicans (Bignoniaceae), Pseudocercospora hymenaeae from Hymenaea courbaril (Caesalpinioideae/Fabaceae), Pseudocercospora solandrae from Solandra sp. (Solanaceae), and Verrucisporota struthanthicola from Struthanthus sp. (Loranthaceae). New reports for Panama are Cercospora glauciana from a new host plant genus (Rhynchospora, Cyperaceae), Pseudocercospora acalyphicola from a new host plant species (Acalypha macrostachya, Euphorbiaceae), Pseudocercospora cecropiae, Pseudocercospora cecropiicola, Pseudocercospora cecropiigena, Pseudocercospora mirandensis, and Ramularia rubella.  相似文献   

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广西兰科植物新记录   总被引:1,自引:0,他引:1  
该文报道了广西兰科植物6个新记录物种,即日本对叶兰[Neottia japonica(Blume)Szlachetko]、吉氏羊耳蒜(Liparis tsii H.Z.TianA.Q.Hu)、小羊耳蒜(L.fargesii Finet)、条裂鸢尾兰(Oberonia jenkinsiana Lindley)、果香兰(Cymbidium suavissimum C.Curtis)和大花斑叶兰[Goodyera biflora(Lindley)J.D.Hooker],分别描述了每个物种的分类学特征,提供了相关的引证标本及地理分布信息,并附有彩色照片以供识别。  相似文献   

15.
长江口水域鱼卵、仔稚鱼种类组成和数量的分布与变化   总被引:1,自引:0,他引:1  
Zhang H  Yang SL  Meng HX 《动物学研究》2012,33(3):255-260
根据2005年4和11月、2006年4和9月在长江河口水域进行的鱼卵、仔稚鱼种类和数量调查,并结合1990年9月和1991年3月的历史数据,对该水域的鱼卵、仔稚鱼群落结构的种类组成和数量的季节变化作了研究,其结果共发现鱼卵、仔稚鱼36种(类),以海洋鱼类种类最多。秋季航次鱼卵、仔稚鱼的平均种类数和丰度均高于春季。河口咸淡水区鱼卵总数显著高于淡水区,而仔稚鱼总数略低于淡水区。与1990—1991年数据相比,2005—2006年春、秋季的鱼卵和仔稚鱼丰度均有所增加。1990、2006年秋季(9月)鱼卵、仔稚鱼种类组成差异较大,特别是翘嘴红鲌和太湖新银鱼丰度差异较大。这些都说明近20年来,长江河口水域鱼卵、仔稚鱼种类组成和数量均发生了明显的改变。  相似文献   

16.
陈新艳 《广西植物》2020,40(8):1127-1131
植物资源普查是掌握植物物种及数量变化的基础,对研究植物的地理分布和生物多样性具有重要意义。通过对2017年—2018年期间福建省本土植物调查过程中采集的植物标本进行整理和鉴定,发现了福建省被子植物5个新记录种,即台湾附地菜(Trigonotis formosana)、浙江琴柱草(Salvia nipponica subsp. zhejiangensis)、笔龙胆(Gentiana zollingeri)、大头茶(Polyspora axillaris)和钝颖落芒草(Piptatherum kuoi),均为福建省新记录种,大头茶属(Polyspora)和落芒草属(Piptatherum)为福建省新记录属。这些新记录植物的发现,丰富了福建省原生植物资源,为植物区系研究提供了新的资料。  相似文献   

17.
This study reports four thrips species from Brazil for the first time: the terebrantians Aptinothrips rufus (Haliday) and Echinothrips caribbeanus Hood; and the tubuliferans Androthrips ramachandrai Karny and Gynaikothrips uzeli (Zimmermann). New data about biological aspects of some of these new records are presented.  相似文献   

18.
在对江汉平原钻孔中的化石硅藻进行鉴定时,发现1个新种类:江汉异极藻(新种)Gomphonema jianghanensis sp.nov.,该种的主要特征为:壳面狭披针形或线性披针形,端部和基部圆形,中轴区窄。中心区宽呈横矩形,在紧靠中心区的一侧具1条很短的线纹,另一侧有时有1条很短的线纹,有时没有线纹,无孤点。壳缝呈直线,在中央区附近略弯向一侧,在极节处折向另一侧。线纹轻微放射状,中部略弯曲,在近顶端处没有线纹,在10μm内,中部具6—13条。长20—30μm,宽4—7μm。4个中国新记录属:楔异极藻属Gomphosphenia Lange-Bertalot、楔月藻属(新记录属)Cymbopleura Krammer、优美藻属Delicata Krammer、尖月藻属Encyonopsis Krammer,8个中国新记录种:微小异极藻Gomphonema minutiforme Lange-Bertalot&Reichardt、较细楔异极藻Gomphosphenia tenerrima(Hustedt)Reichardt、舌状楔异极藻Gomphosphenia lingulatiforme(Hustedt)Lange-Bertalot、瑞克舟形藻Navicula rakowskae Lange-Bertalot、北方羽纹藻岛屿变种Pinnularia borealis var.islandica Lange-Bertalot,舟形盖斯勒藻Geissleria tectissima(Lange-Bertalot)Lange-Bertalot&Metaeltin、岩生楔月藻小变种Cymbopleura rupicola var.minor Krammer和法国尖月藻Encyonopsis falaisensis(Grunow)Krammer,1个种的补充说明:中华优美藻Delicata sinensis Krammer & Metzetin。  相似文献   

19.
This paper deals with six species of smut fungi which were collected in the provinces Yunnan and Gansu in China. Among them, Anthracoidea yunnanensis and Entorrhiza guttiformis are new species. Sporisorium andropogonis-annulati, which is a new combination, Sporisorium montaniensis, Urocystis pseudoanemones, and Ustilago griffithsii are new records for China.  相似文献   

20.
Hughes M  Weir A  Leschen R  Judd C  Gillen B 《Mycologia》2004,96(6):1355-1369
Until now Rhachomyces kenodactyli Balazuc & W. Rossi has been the only species of Laboulbeniales known to occur on Coleoptera in the Bounty, Antipodes, Auckland, Campbell and Snares Islands, which lie 48° to 35° S. Four new species (Diphymyces depressus, Diphymyces leschenii, Laboulbenia subantarctica and Laboulbenia loxomeri) and five new records for the subantarctic (Cucujomyces phycophilus, Diphymyces penicillifer, Laboulbenia sp. 1, Rhachomyces sp. 1 and Teratomyces sp. 1) are reported, increasing the known number of taxa tenfold. An expanded geographic range for Rhachomyces kenodactyli is reported. A relatively high percentage (12%) of known beetle species in the subantarctic serve as hosts for Laboulbeniales. This host utilization rate is higher than that in tropical and north temperate regions. The high proportion of intertidal coleopteran taxa in the subantarctic fauna probably accounts for the greater number of host species utilized. Fungi on intertidal beetles (Omaliinae [Staphylinidae], Oopterus [Carabidae] and Kenodactylus audouini [Carabidae]) are known from many host individuals and collections, while those on terrestrial species are known from few, and in some cases, a single collection or host. The sporadic occurrence of some species encountered increases the likelihood that a few species of Laboulbeniales on Coleoptera probably remain undiscovered in the region.  相似文献   

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