Population size, distribution and habitat selection of the white-tailed eagle Haliaeetus albicilla in the alluvial wetlands of Croatia

From 2003–2006, research on the breeding distribution of the white-tailed eagle (Haliaeetus albicilla) was conducted in Croatia in order to assess the size of the national population. In 125 locations, clear signs of breeding activity were found. An additional 10 presumably active territories were detected but it was not possible to locate the exact position of the nests and confirm the breeding. Based on this, it is concluded that the national breeding population is not less than 135 breeding pairs. The present distribution can be compared with previous reports with the exception of the area along the Ilova and Lonja rivers that have never been reported as an important breeding site. Analysis of the characteristics of 138 nest positions as well as preferences/avoidance of specific structural features were performed. The results showed that white-tailed eagles prefer to build their nests on pedunculate oaks, narrow-leafed ash and white poplars with the greatest preference for mature trees with a diameter above 92.5 cm. The minimal distance between two active pairs was 348 meters. More than 50% of the national population breed less than two km from a large water area and 95% of the population less than four km. More than 95% of the population breed at altitudes lower than 140 m above sea level and are further than one km away from the nearest human settlement, regardless of the availability of forests. According to several parameters (distance to a large water area, elevation, forest presence, distance to the nearest settlement, distance to highways and railways) geographic information system (GIS) helped to determine potential white-tailed eagle breeding areas.     

Development of vegetation patterns in early primary succession

Question: We investigated colonisation filters in early plant community development on a glacial outwash plain. We asked if these were related to seed limitation or to a lack of safe sites, if topographical heterogeneity affected species patchiness and how species life cycles influence successional trajectories. Location: An outwash plain (Skeiðarársandur) in southeast Iceland. Methods: We identified surface heterogeneity at two different scales, ca. 10–15 cm (larger stones and established plants) and ca. 50 m (shallow depressions representing dry river beds) at two study sites. We quantified species cover, flowering plant density, seed production, seed rain, seed bank density, seedling emergence and seedling survival from June 2005 to June 2007 for the whole plant community, and measured seed production for five species. Results: Mean vegetation cover was <2.5% at the sites. Low emergence rates and high seedling mortality were the two main recruitment filters. Only 1.4% of seedlings emerging in 2005 survived into the 2007 growing season. Topographical heterogeneity had little effect on plant colonisation. High annual variation was recorded, and the two study sites (ca. 2 km apart) differed in their colonisation success. Of the five species, establishment of Cerastium alpinum and Silene uniflora was most limited by lack of seeds, whereas establishment of Luzula spicata, Poa glauca and Rumex acetosella was most limited by safe sites. Conclusions: We conclude that colonisation processes and patterns in early primary succession on Skeiðarársandur were largely influenced by stochastic factors.     

Calcareous nannofossils and foraminifers herald the Messinian Salinity Crisis: The Pollenzo section (Alba, Cuneo; NW Italy)

During the Messinian, the Mediterranean area experienced fast and prominent paleoenvironmental changes, culminating in the so-called Messinian Salinity Crisis, with the deposition of the evaporitic series. This work investigates the micropaleontological assemblages in the pre-evaporitic sediments of the Sant’Agata Fossili Marls (SAF) of the Pollenzo section (Cuneo area, North Western Italy). A semiquantitative analysis is carried out on the upper part of the marly and pelitic sediments of the SAF underlying the first gypsum bed, ascribed to the Vena del Gesso Fm. (VDF). The studied interval belongs to the planktonic foraminifer Globorotalia conomiozea Zone and “non distinctive Zone” of Iaccarino and to the calcareous nannofossil MNN11b/c Zone of Raffi et al. (1998, 2003) ( [Raffi et al., 1998] and [Raffi et al., 2003]). Decrease of diversity and abundance of the foraminifer and calcareous nannofossil assemblages is recorded 12 m below the VDG and clearly reflects environmental stress. From bottom to top, six paleoecological events are recorded: (1) the first peak abundance of “small” Reticulofenestra and the last recovery (LR) of planktonic foraminifers; (2) the peak abundance of Pontosphaera japonica and the last recovery of warm water taxa Discoaster spp.; (3) the last recovery of benthic foraminifers; (4) the co-occurring peak abundances of Helicosphaera carteri and Sphenolithus abies, and the last recovery of warm water taxa Amaurolithus spp.; (5) the second peak of “small” Reticulofenestra; (6) the definitive disappearance of calcareous nannofossils. These paleoecological events describe a progressive isolation of the basin from the world ocean and increasingly stressed environment (LR planktonic foraminifers; LR Discoaster spp.), increasing dysoxic to anoxic conditions at the sea floor (LR benthic foraminifers), shallowing of the water column (peak of H. carteri), increasing salinity in surface waters (peak of S. abies), and enhanced nutrient concentration in surface waters (peak of “small” Reticulofenestra); these are related to paleoenvironmental changes predating gypsum deposition at Pollenzo and affecting the whole Mediterranean basin.     

Spatial distribution of ant mounds and effects on soil physical properties in wetlands of the Sanjiang plain, China

Ants constitute a dominant element of soil mesofauna due to their biomass, abundance, richness of species and distribution within terrestrial ecosystems. They are important regulators of soil aggregate structure as they translocate large amounts of soil from the bottom to the soil surface. In doing so, they form biogenic structures (BS) made up of aggregates of different sizes and characteristics, i.e. ant mounds. These BS have varying characteristics according to the ant species and the soil where they carry their activities. Ants are considered soil engineers because of their effects on soil properties, availability of resource and flow of energy and nutrients in soil. Thus, it is important to gain information on their distribution and abundance. Relatively little is known about the spatial distribution of mounds and their role in the soil physical properties in wetlands of the Sanjiang plain, China. We conducted a survey of ant mounds and measured the density, height, and diameter and material composition of different ant mounds. The ecological characteristics of wetlands that ant mounds wide occurrence were also investigated, including soil type, hydrology characters and plant composition. Differences in soil particle composition, bulk density and soil moisture between ant mound and natural meadow were measured to assess the influences of ant mounds on soil physical properties. We also studied the effects of ant mounds on the microtopography of meadows. Ant mounds were found mainly in the transition zone between terrestrial and aquatic habitats, with wetland type, including Calamagrostis augustifolia wet meadow, C.augustifolia marsh meadow, shrubs marsh meadow and Carexmeyeriana–Carexappendiculata wetland, being a significant factor. Most of the mounds detected were inhabited by Lasius flavus Fabricius, Lasius niger Linnaeus and Formica sanguinea Latreille, which occupied 52.9%, 26.5% and 20.6% of the mounds surveyed, respectively. The density, height, diameter and mound composition were significantly different among the mounds of F. sanguinea Latreille, L. flavus Fabricius and L. niger Linnaeus. The average density and diameter of L. flavus mounds was significantly higher than those of other ant mounds. The average height of F. sanguinea mounds was highest among the mounds detected. Mound building activities changed soil particle size distribution, with the silt and clay content of mounds higher than for non-mound soil. Compared with adjacent, non-mound soil, the bulk density (0–30 cm) and water content (0–25 cm) of mound soil were significantly lower, but there were no significant differences between the mound soil of F. sanguinea Latreille and L. flavus Fabricius. The spatial distribution of ant mounds with different height and diameter also changed the micro-geomorphology of the soil surface, increasing the degree of fluctuation of the microtopography. The ant distribution characteristics and their ecological roles respond to a wide range of environmental alterations. The biogenic structures of ant and the specific environment associated with them have been defined as the “functional domain”, a sphere of influence that may significantly affect soil processes at certain spatial and temporal scales. Our results suggest that the distribution and structure of ant mounds can indicate wetland environmental changes, with mounds influencing ecosystem functions and enhancing wetland degradation.     

Demographic genetics of the American beech (Fagus grandifolia Ehrh.) III. Genetic substructuring of coastal plain population in Maryland

Spatiotemporal genetic substructurings were investigated in the American beech population of the east-central coastal plain in Maryland. All trees including seedlings, various sizes of juveniles, and mature trees within the study site (10 × 100 m) were mapped, diameters measured, and leaves collected for allozyme analyses. Eleven polymorphic loci in eight enzyme systems were examined: 6Pgdh2, 6Pgdh3, Acp2, Adh1, Adh2, Fum, Got1, Got3, Lap, Pgi, and Pgm2. A total of 1945 trees were analyzed and 595 multilocus genotypes were detected. Six size-classes and 10 spatial blocks were discriminated for spatiotemporal analyses. Parameters for genetic variations (heterozygosity, Simpson's index, Shannon-Weaver's index, and inbreeding coefficient) decreased in larger size-classes. These genetic parameters fluctuated in spatial blocks of 10 m intervals, in which certain alleles were characteristic of specific blocks. The spatial autocorrelation by Moran's I and coancestry revealed the ranges of genetic relatedness to be only 20–30 m. Multilocus genotype analyses showed that higher genetic variations occur in larger size-classes and at gap openings where seed shadows for mother trees are overlapped. The relationships among reproductive trees, seedlings and juveniles suggested that the seed dispersal range of the American beech is normally in the range of 30–40 m. The mechanisms of a remarkably high genetic polymorphism maintained in this once artificially disturbed and grazed forest are discussed as related to conservation biology.     

一株新的砷还原菌分离鉴定及其对天然矿物臭葱石的溶解作用

【目的】探究江汉平原土著砷还原微生物如何介导臭葱石的溶解和释放过程,以及硝酸盐和硫酸盐对该过程的影响。【方法】采集江汉平原高砷沉积物,利用多轮传代富集方法筛选出一株兼性厌氧砷还原菌;克隆其16S rRNA基因、砷还原酶基因(arsC)、硫代硫酸盐还原酶基因(phsA)、硝酸盐还原酶基因(nar)以获得其分类地位;分析该细菌的As(V)、NO3–、Fe(III)、S_2O_3~(2–)还原功能;利用microcosm技术分析该菌株催化臭葱石中不可溶砷和铁的溶解和释放作用及硝酸盐和硫酸盐对此过程的影响;采用X-射线衍射(XRD)和扫描电镜(SEM)等方法对细菌作用前后的矿物表面形貌进行分析。【结果】16S rRNA基因测序结果表明该细菌为柠檬酸杆菌属(Citrobacter sp.),故命名为Citrobacter sp. A11;在Citrobacter sp. A11作用下,0.45 mmol/L As(V)在4 d内被还原成As(III),2.0 mmol/L S_2O_3~(2–)在6 d内被还原成S~(2–),1.0 mmol/L Fe(III)在3 d内被还原成Fe(II),140.0 mg/L NO_3~–在28 h内被还原成NO_2~–;经过28 d该细菌的催化作用使得体系中不可溶砷和铁的释放量分别为33.68μmol/L、51.93μmol/L;硫酸根的加入使得砷和铁的释放量分别增长了41.04%和34.30%,硝酸根的加入则使砷和铁释放量分别降低了35.07%和53.46%。XRD、SEM-EDS分析表明,细菌作用后的臭葱石表面形貌发生明显改变,并出现细小且分散的溶解性颗粒。【结论】本次研究从江汉平原高砷沉积物中富集分离得到一株兼性厌氧砷还原细菌Citrobacter sp. A11,能有效还原As(V)、S_2O_3~(2–)、NO_3~–、Fe(III);砷还原细菌Citrobacter sp. A11能显著促进臭葱石中砷和铁的溶解和释放,硫酸根离子的存在会促进细菌介导臭葱石中固态砷、铁的释放,而硝酸根离子的存在则对此过程起明显抑制作用。     

Preliminary studies of neurosensory and cardiopulmonary health compromise in captive- bred Rhesus macaques (Macaca mulatta) suffering scoliosis

Background It has been widely documented that quadrupedal animals rarely display natural spontaneous scoliotic rachis deviations of the spinal column. The objective was to determine spinal deformities developed by geriatric monkeys of the Macaca mulatta species, by radiographical and tomographical studies of the vertebral column correlating morphological changes with altered physiological parameters and electrical neurosensorial conductivity of somatosensory‐evoked potentials (SEPs). Materials and methods A cohort of six geriatric monkeys was used: three non‐scoliotic subjects and three monkeys with naturally acquired true scoliosis. Results Radiographic and tomographic studies depicted a thoracic curvature displaying a left‐sided thoracic vertebral rotation. The evaluation of physiological parameters demonstrated significant differences in the respiratory rate, as it was observed for the diastolic blood pressures, which showed a decrease in the monkeys with scoliosis compared with healthy monkeys. Regarding the SEPs studies, the non‐parametric test for independent samples Mann–Whitney U test displayed a significant difference observed at the left and right thoracic derivative in P1; while regarding the study of upper limbs, a significant difference was seen at the Erb’s point derivative, left afferency in P1, showing in all the derivatives an increase in latency in monkeys with scoliosis versus monkeys in the control group. Conclusions This study has demonstrated that quadrupedal animals can develop true scoliosis showing an analogous way to that occurring in humans.     

The role of fungi in periodically inundated Amazonian forests

In a comparative survey the terms (terra-firme) flood plain, igapó, várzea with and without black water influence are reviewed and the importance of ectotrophic mycorrhiza for their definition emphasized. Várzea alta with fluvisol base is briefly characterized and a first list of Basidiomycetes collected in it is provided. These are all non-mycorrhizal litter fungi.     

湖北省不同类型土地整治生态效应评价

基于土地整治引起的变化特征,建立生态服务价值估算模型,定量评价湖北省内江汉平原、鄂西山地和鄂中丘陵3种不同类型土地整治引起的生态效应.结果表明：土地整治后,平原型项目区总生态服务价值损失0.3%,食物生产等4项功能的生态服务价值增加,水源涵养等5项功能的生态服务价值减少;丘陵型项目区总生态服务价值损失14.6%,食物生产的生态服务价值提高55.2%,其余8项功能的生态服务价值均减少;山地型项目区总生态服务价值损失19.9%,食物生产的生态服务价值提高24.9%,其余8项功能的生态服务价值均减少.丘陵和山区土地整治存在明显的“以生态换生产”的价值转换过程.     

松嫩草地水淹干扰后的土壤种子库特征及其与植被关系

研究了松嫩平原羊草草地不同强度水淹干扰对土壤种子库种类组成、物种多样性及其与植被物种组成的相似性关系等的影响。结果表明：（1）随着水淹强度的加重或水淹持续时间的延长,相应地段的土壤种子库物种数目和种子存量都呈减小趋势;（2）土壤种子库的种类成分在干扰样带和对照样带间差异明显,而受水淹干扰的样带之间种子库的种类组成差异不大,表明洪水漂移行使了繁殖体传播和散布的功能;（3）随水淹干扰强度增加,种子库物种多样性指数减小;（4）种子库与地上植被物种组成相似性普遍较低,其原因是主要靠营养繁殖以更新种群的多年生根茎植物经常在植被中出现而不在种子库中出现;（5）种子库与地上植被物种组成相似性随水淹干扰强度增加而下降,表明了水淹干扰对种子库与地上植被物种组成相似性有一定程度的影响。