不同生长调节剂及基质对越南粉苞茉莉扦插生根的影响

为探索越南粉苞茉莉(Jasminum dichotomum)扦插生根的影响因素,建立扦插繁育技术体系,以1年生越南粉苞茉莉枝条为插穗,采用L16(44)正交试验,探讨生长调节剂种类及其浓度、处理时间、基质种类对越南粉苞茉莉茎段扦插生根的影响,利用排队评分法和公式评分法对正交试验进行分析。结果表明,A2B3C3D2为试验的最优处理组合,即将插穗在250 mg·L-1 IBA和500 mg·L-1 NAA混合药剂中浸泡20 min后扦插于沙子上。     

Environmental drivers of the bryophyte propagule bank and its comparison with forest-floor assemblage in Central European temperate mixed forests

Species richness, composition and abundance of the bryophyte diaspore bank of Central European temperate mixed forests were compared with the forest-floor bryophyte assemblage. The impact of environmental variables and anthropogenic disturbances, including tree species composition, stand structure, microclimate, light conditions, soil and litter properties, management history, and landscape properties, potentially influencing bryophyte diaspore bank assemblages were explored. Thirty-four, 70–100 years old mixed stands with differing tree species composition were examined in the ?rség National Park, Western Hungary. The diaspore bank was studied by soil collection and cultivation, and data were analysed by multivariate methods. Contrary to the forest-floor bryophyte assemblage, where substrate availability, tree species composition and stand structure were the most influential environmental variables, the composition and abundance of the diaspore bank was mainly affected by site conditions (microclimate, litter and soil properties). Species richness of the bryophyte diaspore bank was lower than that of the forest-floor bryophyte assemblage. Short-lived mosses (colonists, short-lived shuttles) were dominant in the diaspore bank, as opposed to the forest-floor bryophyte community, where perennial mosses dominated. In the studied forests, the importance of the bryophyte diaspore bank was relatively low in the regeneration and maintenance of the forest-floor bryophyte vegetation.     

Phlebotominae of epidemiological importance in cutaneous leishmaniasis in northwestern Argentina: risk maps and ecological niche models

In Argentina, 58.2% out of the 8126 Cutaneous Leishmaniasis (CL) incident cases accumulated from 1954 to 2006 were reported in the provinces of Salta and Jujuy. The aim of this study was to develop an exploratory risk map and a potential distribution map of the vector, in order to offer recommendations for CL prevention. A total of 12 079 Phlebotominae (Diptera: Psychodidae) belonging to the species Lutzomyia neivai (Pinto), Lu. migonei (França), Lu. cortelezzii (Brèthes), Lu. shannoni (Dyar), Lu. quinquefer (Dyar) and Brumptomyia spp. (França & Parrot) were captured. Potential distribution models were created for two species, Lu. neivai (incriminated vector of Leishmania braziliensis) and Lu. migonei, associated with domestic animals in Argentina and that in turn could be involved as a link between zoonotic transmission cycles and anthropozoonotic. The Maximum Entropy Modeling System (MaxEnt) was used. The Jackknife test was performed, and the ‘rainfall of the driest month’ was the variable that best generalized the models. Accuracy was evaluated by the area under the curve (AUC) and validated by the Cohen's kappa index. This approximation provides a new analytical resource of high potential for the prevention of the disease, in order to allocate resources properly and to develop the most suitable strategies for action.     

Aspects of reproduction and their implications for the conservation of the endangered limpet,Patella ferruginea

Summary

The protandric limpet, Patella ferruginea G., is the most endangered marine species in the Western Mediterranean and is at serious risk of extinction. Nevertheless, its biology and ecology are little known. In the present work, several reproductive aspects are studied. Recruitment take place in June and the largest individuals are the most scarce. The sex ratio is slanted towards the largest sizes, and the species seems to show sex change at sizes from 60 mm upwards, although males can be observed up to 80 mm. There is no correlation between size of oocytes and shell length; however, the larger females contribute greatly to the reproductive event, with high fecundity and GSI values. The mean diameter of oocytes was observed to be 149.78 μm, whereas the heads of spermatozoa were 3.78 μm long. The results of the present study increase the maximum length for males by double that cited in previous literature and highlight the importance of strictly protecting females (i.e., most of the largest individuals, >60 mm), since their population percentage is very low, in order to develop adequate strategies to preserve the species.     

Observations on the development and maintenance of the deep sea barnacle,Octolasmis aymonini geryonophila (Pilsbry)

Thirty-two pedunculate barnacles, O. a. geryonophila, were maintained in culture for a period of 2 yr in the laboratory. These barnacles were obtained from the pleopods and mouth parts of the giant marine isopod, Bathynomus giganteus, which had been collected, at a depth of 200 fathoms, in the Gulf of Mexico.

The carina, scutum, mandible and maxilla of adult barnacles were typical of deep water species. However, the tergum and labrum were intermediate between those of shallow and deep water species.

Adults 3.1–4.1 mm in length were cultured in sea water (15–19°C), and fed on benthic copepods such as Tisbe furcata and Laophonte sp. Three broods of nauplii from 8 barnacles were obtained in 2 yr. Larvae were reared on plankton collected from Coney Island waters in which nauplii reached Stage IV in 10–14 days at 16°C. Isochrysis galbana and Thalassiosira pseudonana individually or in combination maintained nauplii to Stage IV, but with very high mortality. The lack of spines on the carapace edge of the nauplii distinguishes this deep water species from the shallow water form, O. mulleri.     

Habitat complexity affects how young of the year Atlantic cod Gadus morhua perceive predation threat from older conspecifics

The response of age 0+ year juvenile Atlantic cod Gadus morhua to the presence of age 1+ and age 3+ year conspecifics was measured with and without cover available. Juveniles reacted by aggregating more closely and maintaining distance from older conspecifics in an experimental setting without cover but only to age 3+ year conspecifics when cover was available. The results indicate that prior residence of older juveniles can affect age 0+ year juveniles during benthic settlement and highlights the conservation value of structurally complex nursery habitats.     

以小时为步长的大兴安岭兴安落叶松林地表可燃物含水率预测模型

应用时滞平衡含水率法(包括Nelson和Simard两种)及气象要素回归法,以小时为步长对大兴安岭地区阳坡上部落叶松林下地表细小死可燃物进行动态含水率测定,分析了不同郁闭度林分的预测误差.结果表明:以小时为步长的可燃物含水率预测方法适用于大兴安岭地区的典型落叶松林分,Simard法预测平均绝对误差为1.1%,平均相对误差为8.5%,低于Nelson法和传统的气象要素回归法,接近同类研究的误差范围;同一坡度、坡位上,不同郁闭度下的可燃物含水率变化差异较大,使用以小时为步长的可燃物含水率预测方法,应根据不同地区林分和地点选择合适的平衡含水率模型,或建立基于林分的可燃物含水率模型.     

Feeding ecology of mackerel and dietary overlap with herring in Icelandic waters

The Northeast Atlantic mackerel (Scomber scombrus) has been extending its summer feeding distribution north and west, including around Iceland, since around 2006. The objective of this study is to quantify the weight gain and total food consumption of mackerel and to evaluate the food competition between mackerel and herring (Clupea harengus) feeding in the marine ecosystem around Iceland during the summers 2009–2011. Mackerel feeding in Icelandic waters gained around 43% on average in weight during these summers. Based on swept-area abundance estimates of mackerel from an international survey in 2011 and available estimates of food conversion efficiency in mackerel, the weight gain in Icelandic waters in 2011 corresponded to a total consumption of around 3.4 (2.4?4.5) million tonnes. Overall, 98% of 2314 mackerel, 91% of 398 Icelandic summer-spawning herring and 96% of 424 Norwegian spring-spawning herring stomachs, collected over the summers 2009?2011, contained food. The mean weight of the stomach content of mackerel was higher than for herring in all the years. While the stomach content weight of mackerel was generally highest in southeastern and southwestern areas, it was highest for herring in western, eastern and northern areas. Analysis of stomach contents showed that Copepoda were the most important food of mackerel in most areas, while Copepoda and Euphausiacea were the most important food items for herring. Fish prey contributed a higher proportion in stomachs of mackerel than herring, although relatively low for both species.