萼花臂尾轮虫种复合体内三个姐妹种的形态差异

应用单因子方差分析和判别分析方法,分别比较了采自芜湖市3个自然水体的萼花臂尾轮虫种复合体内3个姐妹种(分别以克隆HE1和HE5、克隆HE3和SE1、克隆LE9为代表)的成体和幼体的形态差异。结果表明,克隆HE3成体的各形态参数均最小,而克隆HE1和LE9成体的各形态参数间无显著的差异;克隆HE1和HE3幼体的前中棘刺间距离和后侧棘刺长度、克隆LE9和HE1幼体的前侧棘刺间距离以及前中棘刺和侧棘刺间距离均无显著性差异,轮虫幼体的其它形态参数均以克隆LE9最长,克隆HE1次之,克隆HE3最短。对克隆HE1、HE3和LE9幼体有明显差异的形态参数所作的分布图显示,它们的分布区有很高程度的重叠。以判别分析建立的判别函数对3姐妹种成体的综合判别率中形态分析Ⅰ为47.8%,形态分析Ⅱ为55.6%;对3姐妹种幼体的综合判别率中形态分析Ⅰ和Ⅱ均为71.1%;两种形态分析对克隆HE1判别准确率均较低,分别为0-76.7%和0-74.2%;依据形态特征无法准确甄别萼花臂尾轮虫姐妹种。     

Gap-phase regeneration in a tropical montane forest: the effects of gap structure and bamboo species

To study the influence of gap structure and bamboo species on the regrowth of montane Atlantic forest, colonization by plants was characterized in 30 treefall gaps (30.3–500.5 m²). The study was conducted at Santa Virgínia (45°30 W, 23°17 S), a 4970-ha reserve of Atlantic montane forest in southeastern Brazil. Area covered by bamboos ranged from 0% to 100% of gap area. Average height of surrounding canopies ranged from 12 to 30 m. As gap are covered by bamboo and average height of surrounding canopies increased, both density and richness of pioneer woody species decreased. Density and richness of shade-tolerant species were negatively influenced by gap area. Low-light-demanding species of Miconia, Leandra and Rapanea accounted for the majority of both pioneer species and individuals sampled, whereas high-light demanding pioneers of Cecropia, Alchornea and Tibouchina were poorly represented. We suggest that in the Atlantic montane forest bamboo species compete for gaps, excluding other light-demanding pioneers. This results in an overall reduction of pioneer species richness in the Atlantic forest.     

First observation on mating and reproductive seasonality in maned sloths <Emphasis Type="Italic">Bradypus torquatus</Emphasis> (Pilosa: Bradypodidae)

Information on mating season is of paramount importance for our understanding of reproductive behavior, yet little is currently known about the breeding season of Xenarhtra as a whole and sloths in particular. A pair of maned sloths was observed copulating in September 2005 in the Atlantic Forest region of south-eastern Brazil. Our studies on mating of the manned sloth as well of other hitherto unpublished records of newborn sloths seen in the wild, together with a review of previous information, indicate that B. torquatus is a seasonal breeder. Infants are born predominantly at the end of the wet season and beginning of the dry season (February–April), and copulation concentrates in the late dry and early wet seasons (August–October). This strategy allows for the energy-demanding gestation and lactation to take place during the less stressful period of the year.     

A set of polymorphic microsatellite loci for Vriesea gigantea and Alcantarea imperialis (Bromeliaceae) and cross‐amplification in other bromeliad species

Fifteen polymorphic microsatellite markers were isolated and characterized in two species of Bromeliaceae: Vriesea gigantea and Alcantarea imperialis. The number of alleles observed for each locus ranged from three to 16. The loci will be used for studies of the genetic structure of natural populations, reproductive biology, and evolutionary relationships among and within these genera. A cross‐amplification test in 22 taxa suggests that the markers will be useful for similar applications in numerous other bromeliad species.     

Coexistence and geographical distribution of Leguminosae in an area of Atlantic forest in the semi-arid region of Brazil

Understanding the factors that affect plant species distribution and coexistence in areas with high plant species diversity is a challenge for ecologists.According to some authors,species occupy specif...     

Metropolitan lizards? Urbanization gradient and the density of lagartixas (Tropidurus hispidus) in a tropical city

Urbanization, with its cohort of environmental stressors, has a dramatic effect on wildlife, causing loss of biodiversity and decline in population abundance customarily associated with increasing levels of impervious surface and fragmentation of native habitats. Some studies suggest that faunal species from open habitats, and with higher abundance in natural environments, seem more likely to tolerate and live in urban environments. Here I evaluate how the level of urbanization affects lagartixas (Tropidurus hispidus) one of the most common lizards found in open vegetation ecosystems in NE Brazil. I surveyed a total of 47 transects across sites that differed in proportion of impervious surface (high, mild, peri‐urban, and rural). I also collected specific biotic (herbaceous cover, tree, and arthropod abundance) and abiotic (amount of shelters and impervious surfaces) factors that could affect lagartixas abundance. Ants were the most common arthropod both in the rural and urban environment. Lagartixas thrive in urban environments, and trees and shelter were key predictors of their abundance. Lagartixas show a clear association with use of artificial structures. The low densities of lagartixas in rural areas and higher density in urbanized areas suggest that they colonized urban areas due to the hard surfaces and they probably are not exploiting a novel habitat, but somewhat responding to conditions resembling those in which they evolved. Finally, lagartixas are extremely common in tropical cities, they have a suite of features that are associated with selective pressures in cities and they might play a key functional role in urban ecosystems making this lizard an excellent system for the study of ecology and adaptation to the urban environments.     

Comparative floral preferences in nectar and pollen foraging by Scaptotrigona postica (Latreille 1807) in two different biomes in São Paulo (Brazil)

To describe the trophic resources used by Scaptotrigona postica, honey and bee bread samples were taken monthly from May 2015 to December 2016 at two different localities. Fontes do Ipiranga State Park (PEFI), an urban remnant of the Atlantic Forest, and the Mogi Guaçu Biological Reserve (RBMG), in the Cerrado. Two colonies were kept in each site. Samples were analysed with the melissopalynological method in order to calculate the relative frequencies. Principal component analysis was used to compare the similarity between the samples and to examine the influence of quantitative and qualitative data on the ordination of the pollen types. Similarity tests were performed to compare the pollen spectra of the bee bread and honey samples between the study sites and seasons. Hence, 69 and 61 pollen types were identified in 33 honey and 29 bee bread samples. The main families in honey were Asteraceae, Euphorbiaceae and Fabaceae; in bee bread Fabaceae, Myrtaceae and Sapindaceae were the main families for both localities, followed by Asteraceae, Euphorbiaceae and Solanaceae at the RBMG. The results showed that the species maintains its floral preferences regardless of the biome in which it occurs. Also, demonstrates that the bees make use of nectariferous and polliniferous sources available in the preserved areas as well as in its surroundings. There is a risk of pesticides exposure caused by the use of trophic resources of cultivated plants by this bee. This points to the need for further studies.     

Identification of sympatric bat species by the echolocation calls

One hundred and thirty-eight echolocation calls of 63 free-flying individuals of five bat species (Rhinolophus ferrumequinum,Myotis formosus,Myotis ikonnikovi,Myotis daubentoni and Murina leucogaster)were recorded (by ultrasonic bat detector (D980)) in Zhi'an village of Jilin Province,China.According to the frequency-time spectra,these calls were categorized into two types:FM/CF (constant frequency) / FM (R.ferrumequinum) and FM (frequency modulated)(M.formosus,M.ikonnikovi,M.daubentoni and M.leucogaster).Sonograms of the calls of R.ferrumequinum could easily be distinguished from those of the other four species.For the calls of the remaining four species,six echolocation call parameters,including starting frequency,ending frequency,peak frequency duration,longest inter-pulse interval and shortest inter-pulse interval,were examined by stepwise discriminant analysis.The results show that 84.1% of calls were correctly classified,which indicates that these parameters of echolocation calls play an important role in identifying bat species.These parameters can be used to test the accuracy of general predictions based on bats' morphology in the same forest and can provide essential information for assessing patterns of bat habitat use.     

Identification of sympatric bat species by the echolocation calls

One hundred and thirty-eight echolocation calls of 63 free-flying individuals of five bat species (Rhinolophus ferrumequinum, Myotis formosus, Myotis ikonnikovi, Myotis daubentoni and Murina leucogaster) were recorded (by ultrasonic bat detector (D980)) in Zhi’an village of Jilin Province, China. According to the frequency-time spectra, these calls were categorized into two types: FM/CF (constant frequency) / FM (R. ferrumequinum) and FM (frequency modulated) (M. formosus, M. ikonnikovi, M. daubentoni and M. leucogaster). Sonograms of the calls of R. ferrumequinum could easily be distinguished from those of the other four species. For the calls of the remaining four species, six echolocation call parameters, including starting frequency, ending frequency, peak frequency duration, longest inter-pulse interval and shortest inter-pulse interval, were examined by stepwise discriminant analysis. The results show that 84.1% of calls were correctly classified, which indicates that these parameters of echolocation calls play an important role in identifying bat species. These parameters can be used to test the accuracy of general predictions based on bats’ morphology in the same forest and can provide essential information for assessing patterns of bat habitat use. __________ Translated from Journal of Northeast Normal University (Natural Science Edition), 2006, 38 (3): 109–114 [译自: 东北师范大学学报(自然科学版)]