Mycorrhiza in sedges—an overview

Most terrestrial plants associate with root-colonising mycorrhizal fungi, which improve the fitness of both the fungal and plant associates. However, exceptions exist both between and within plant families failing to associate with mycorrhizal fungi or in the incidence and the extent of mycotrophy, which may vary greatly. Sedges are important pioneers of disturbed habitats and often dominate vegetations like wetlands, and arctic and alpine vegetations, in which the mycorrhizal inoculum in the soil is often low or absent. In the past, sedges were often designated as non-mycorrhizal, though limited reports indicated the presence of mycorrhiza in certain species. However, studies since 1987 indicate widespread occurrence of mycorrhiza in sedges. Based on these studies, the family Cyperaceae is no longer a non-mycorrhizal family, but the mycorrhizal status of its members is greatly influenced by environmental conditions. Further, sedges appear to have several morphological adaptations to thrive in the absence of mycorrhizal association. Though mycorrhizal associations have been noted in many sedge species, the ecological role of this association is not well documented and no clear generalisation can be drawn. Similarly, the role of mycorrhizal fungi on sedge growth and nutrient uptake or non-nutritional benefits has yet to be fully ascertained. This paper reviews the current information available on the incidence of mycorrhiza in sedges and the possible reasons for low mycotrophy observed in this family.     

Bolboforma — an overview

A summary of the present knowledge ofBolboforma is presented in this paper. The genusBolboforma contains a diverse group of marine, mostly single-chambered enigmatic microfossils (phytoplankton, possibly Chrysophyta) which produced calcitic monocrystalline spheroidal tests with or without inner cysts and with various types of ornamentation. The genusBolboforma occurs in the time interval between late Early Eocene to Late Pliocene, at middle and higher latitudes, and thus, has not been recorded in Quaternary to Recent Sediments. The genus is represented globally, but the first and the last occurrence of the genus appear to be spatially diachronous in both hemispheres.Bolboforma started in the southern hemisphere at the Campbell Plateau (SW Pazific) during the Early Eocene approximately 53 Ma ago, and the genus lived there until latest Miocene times (5.3 Ma at the Kerguelen Plateau, Southern Indian Ocean). The first occurrence ofBolboforma in the northern hemisphere is observed in Upper Eocene Sediments (ca. 36.5 Ma) in the Labrador Sea (North Atlantic), and its youngest occurrence is observed in the Hatton-Rockall Basin (North Atlantic) in the Late Pliocene at 2.84 Ma. Well established and common species permit the definition of nineteenBolboforma zones/subzones. Not all of these are observed in both hemispheres. In the southern hemisphere all four Paleogene zones, but only eight Neogene zones are present, in the northern hemisphere only one Paleogene zone, but fourteen Neogene zones have been determined. Bolboforma distribution, which appears to be broadly bipolar in temperate to cool regions at middle to higher latitudes, aso seems to be linked to the evolution of surface watermasses and their boundaries.      

The history of comparative anatomy in Jena — an overview

Summary Comparative anatomy and zoology both have long academic traditions in Jena. At first, the two subjects developed in parallel and had many similarites in research topics. This development is covered in the first part of the paper. The close relationship between the two subjects started to break apart when Carl Gegenbaur and Ernst Haeckel were active at Jena University. In 1865 Haeckel became the first full professor of zoology in Jena, and zoology became more independent from comparative anatomy. In the second part of our paper, we follow the developments in comparative anatomy in Jena from Gegenbaur’s immediate students up until the end of Hans B?ker’s tenure in Jena in the mid-1930s. Certain subjects are in focus throughout this period, for example vertebrate head morphology and development, (the “head problem”), the relationship between anatomy and biology, and evolutionary questions. Some of these subjects have remained important research topics in zoology and comparative anatomy in Jena until the present day.     

Economics of wildlife management—an overview

This study makes an explorative overview on two main research topics in economics of wildlife management: determination of population sizes and policy design. The results point out a large and comprehensive research on each of these issues, in particular on the estimation of values and costs of wildlife, where this information is necessary for the determination of population size. A drawback is that most of the value and cost studies do not relate their estimates to wildlife population size, which limits their usability for efficient policy design. Most valuation studies estimate the recreational value of hunting, which can range between 13 and 545 USD/hunting day (in 2013 prices), and two thirds of the included studies have been applied to wildlife in the USA. A majority of the studies on the costs of wildlife management calculate losses from carnivore predation on livestock and ungulate damage to crops, while a few consider dispersal of diseases and the cost of traffic collisions. Unlike valuation studies, several of the cost estimates apply to wildlife in developing and emerging economies. With respect to policy design the literature, which is mainly theoretical, suggests economic incentives for conflict resolution, where those suffering from wildlife damages are compensated for their losses. However, there are some issues which remain to be addressed by economists: relating costs and benefits to wildlife populations; estimating values and costs of wildlife in developing countries; evaluating wildlife policies in practice; addressing implications of uncertainty in population size, costs, and benefits for policy design; and estimating transaction costs for implementation and enforcement of wildlife policies.     

Feeding habits ofMysis relicta — an overview

Mysis relicta has been recognized as an important component of many limnetic food webs. The first approach to studying the feeding habits ofM. relicta was the analysis of stomach contents. Assumptions regarding stomach content analysis have been tested and seasonal feeding estimates ofM. relicta have been reported recently. Laboratory grazing and/or predation experiments have recently been completed usingM. relicta primarily from Lakes Michigan and Tahoe.Mysis relicta is concluded to be opportunistic, capable of utilizing a variety of food resources. It may play an important role in structuring limnetic food webs.     

Building the mammalian cochlea — an overview

The mammalian cochlea is a highly intricate organ responsible for hearing. Numerous specialized cell types residing in the cochlear participate in processing and relaying sound information to the brain. In general, cells in the cochlea are divided into three major types: sensory, neural, and non-sensory. Sensory cells are a group of cells in the organ of Corti consisting of hair cells and supporting cells. Sensory hair cells play a primary role in detecting and processing sound in the form of vibrations. Neural cells are the neurons and glia in the spiral (cochlear) ganglion that relay the processed sound signals in the form of a neurotransmitter to the brain. Other non-sensory cells include all other cell types providing architectural and functional support. Building a functional cochlea requires tightly orchestrated, spatial and temporal regulation of gene expressions. Disruption of the normal gene expression patterns can cause developmental failure of the organ, which can lead to permanent hearing loss. Thus, comprehensive understanding of genes contributing to cochlear development is crucial for elucidating the pathological mechanisms of hearing loss. This article is intended to provide an overview of mammalian cochlear development, focusing on genes involved in its early patterning.     

An editorial overview： HIV/AIDS in China

China has come a long way in fighting against HIV/AIDS epidemic. The Chinese government has taken an active role in combating this detrimental disease and such a welcome attitude by the Chinese government will certainly provide a positive spin on its effort in reducing the HIV/AIDS epidemic in China.     

Rice field ecology and fish culture — an overview

Rice fields are an integral part of the landscape throughout most of the tropics. Rice is also grown widely in higher latitudes. Most rice cultivation is done in flooded fields where a temporary aquatic fauna is generated. Rice cultivation has sustained some of the oldest civilizations but the use of the aquatic phase for raising a crop of fish has not been practiced widely although fragmentary records indicate that rice and fish have been cultivated concurrently but rarely over 2 or 3 millennia. We have more reliable records of rice and fish culture in rice fields during the past 150 years.Rice cultivation is now very highly mechanized and uses high fertilizer and pesticide inputs and extensive irrigation facilities have been constructed to increase the area of rice cultivation and enhance yields. Rice cultivation also provides a suitable habitat for the breeding of mosquitoes, some of which are vectors for diseases. It appears that in regions outside the tropics aquatic pests of rice are also encountered. In the tropics indigenous fishes and other organisms including copepods act as biological control agents for mosquitoes and aquatic rice pests.The rice field is usually a successor of shallow marshes or a lowland area which can be supplied with adequate water. In addition deep water rice is grown in permanent marshes and rice is also grown in terraced hillsides, not to mention relatively dry localities where dry-land rice is cultivated. The marsh habitat is usually rich in plant and animal species. Some of these survive in rice fields. The water supplied to rice fields come via irrigation systems which bring a complement of plants, animals, and other organisms seasonally to colonize the rice field. The rice field is thus a new habitat, like a reservoir, with some similarities to a marsh but manipulated for cultivation of rice. This creates a unique, temporary and rapidly changing habitat which is often very productive and can be used to raise fish on an artisanal or intensive scale.Fish culture in rice fields has had a checkered history during the past 150 years when records are available. Its earlier history is obscure. Long-term records of fish culture activities are not available from any part of the world although apparently thriving enterprises seem to have existed in Japan, Italy, USSR and China. Attempts to culture fish in rice fields have been made on all continents except Australasia and Antarctica of course. At the present time the focus of rice-cultivation seems to have shifted to China, Indonesia, and Thailand. Whether this enterprise will endure even in these countries cannot be predicted with any degree of certainty.     

Invasive species: reality or myth?

In view of the recent debate on the future of invasion biology, we argue that species could be regarded as invasive only when after adaptation in non-native habitats they reach yet another fitness maximum. We suggest that invasion biologists need to unambiguously clarify what constitutes being “invasive” to refute those who call for an end to invasion biology.     

Multiple phenological responses to climate change among 42 plant species in Xi’an, China

Phenological data of 42 woody plants in a temperate deciduous forest from the Chinese Phenological Observation Network (CPON) and the corresponding meteorological data from 1963 to 2011 in Xi’an, Shaanxi Province, China were collected and analyzed. The first leaf date (FLD), leaf coloring date (LCD) and first flower date (FFD) are revealed as strong biological signals of climatic change. The FLD, LCD and FFD of most species are sensitive to average temperature during a certain period before phenophase onset. Regional precipitation also has a significant impact on phenophases of about half of the species investigated. Affected by climate change, the FLD and FFD of these species have advanced by 5.54 days and 10.20 days on average during 2003–2011 compared with the period 1963–1996, respectively. Meanwhile, the LCD has delayed by 10.59 days, and growing season length has extended 16.13 days. Diverse responses of phenology commonly exist among different species and functional groups during the study period. Especially for FFD, the deviations between the above two periods ranged from ?20.68 to ?2.79 days; biotic pollination species showed a significantly greater advance than abiotic pollination species. These results were conducive to the understanding of possible changes in both the structure of plant communities and interspecific relationships in the context of climate change.     

Schistosoma intercalatum: an endangered species in Cameroon?

Despite the extremely wide distribution of both intermediate (snail) and definitive hosts, the species Schistosoma intercalatum has a highly restricted distribution in parts of West Africa (Cameroon, Equatorial Guinea, Gabon, Nigeria, Democratic Republic of Congo and S?o Tomé). Recent studies showed that the epidemiology of this species is very dynamic, including invasions and extinctions. This article reviews the epidemiology of S. intercalatum in Cameroon, where the species is endangered, and analyses its overall status in Africa. The possible reasons for the limited distribution of S. intercalatum are discussed.     

Latitudinal changes in species diversity of permafrost wetland plant communities in Great Xing’an Mountain valleys of Northeast China

Studying the changes of species diversity in plant communities along latitude gradients is important to discover the correlation between biodiversity and environmental factors. Along the main ridges of the Great Xing’an Mountains, 12 natural permafrost wetlands in the valleys were investigated from north to south. Latitudinal changes in species diversity were analyzed with regressive analysis. About 150 plant species were recorded and were found to be in the 12 permafrost wetland plant communities. Most plants belong to the Compositae or Gramineae. The number of family, genus and species increased significantly in the herb layer with decreasing latitude (P < 0.01), but decreased significantly in the shrub layer (P < 0.01). Species composition and the orders of dominant species in the plant communities by importance value changed along latitude. Latitudinal changes of α-diversity in permafrost wetland plant communities were different in the herb and shrub layers. With decreasing latitude, species richness and species diversity increased in the herb layer; but decreased in the shrub layer. The opposite patterns were found for species dominance. Species evenness in the shrub layer decreased with decreasing latitude. ?-diversity in the herb and shrub layers decreased first, and then increased, and finally decreased with increasing latitude. Species composition in the herb layer was similar among the plots at higher latitudes.     

Latitudinal changes in species diversity of permafrost wetland plant communities in Great Xing’an Mountain valleys of Northeast China

Studying the changes of species diversity in plant communities along latitude gradients is important to discover the correlation between biodiversity and environmental factors. Along the main ridges of the Great Xing’an Mountains, 12 natural permafrost wetlands in the valleys were investigated from north to south. Latitudinal changes in species diversity were analyzed with regressive analysis. About 150 plant species were recorded and were found to be in the 12 permafrost wetland plant communities. Most plants belong to the Compositae or Gramineae. The number of family, genus and species increased significantly in the herb layer with decreasing latitude (P < 0.01), but decreased significantly in the shrub layer (P < 0.01). Species composition and the orders of dominant species in the plant communities by importance value changed along latitude. Latitudinal changes of α-diversity in permafrost wetland plant communities were different in the herb and shrub layers. With decreasing latitude, species richness and species diversity increased in the herb layer; but decreased in the shrub layer. The opposite patterns were found for species dominance. Species evenness in the shrub layer decreased with decreasing latitude. ?-diversity in the herb and shrub layers decreased first, and then increased, and finally decreased with increasing latitude. Species composition in the herb layer was similar among the plots at higher latitudes.     

Two species in Hymenochaetaceae （Basidiomycota） new to China

1 INTRODUCTION Wood-inhabiting fungi from northern China were investigated extensively during last ten years, and the species in the area are relatively well known （Dai 2000; Dai et al. 2006, 2007; Wei et al. 2005; Yuan et al. 2006）. However, they are scantily reported in tropical forests of China （Dai et al. 2001, 2002, 2004）. By the support of the Ministry of Science and Technology of China, two field investigations were made in Jianfengling and Bawangling Nature Reserve of Hainan Province in 2006.     

Sediment-associated contaminants — an overview of scientific bases for developing remedial options

The review article covers three major aspects of scientific research on sediment-associated contaminants during the last 20 years: (i) identification and monitoring of sources and distribution (sampling; sample preparation; analyses, mainly of non-residual fractions; estimation of pollution potential); (ii) study of processes and mechanisms of pollutant transfer (interactions between dissolved and particulate element species; particle environments; transport and diagenesis: colloids; surface microlayers; particle related processes; bioturbation; dredging operations; remobilization of toxic elements; bioaccumulation of organic chemicals: solid/dissolved distribution of contaminants); (iii) assessment of the environmental impact of particle-bound pollutations (chemical extraction sequence; sediment bioassay; combined chemical/biological test procedures). Enstead, empirical tests developed from multi-disciplinary research on biological, chemical and physical factors are applied for assessing the reactivity, mobility and bioavailability of sediment-bound pollutations and for estimating the validity of remedial measures.     

The relative of species pools in determining plant species richness: an alternative explanation of species coexistence?

Explanations of the pattern of species have traditionally relied on small-scale, local processes occurring in ecological time. Differences in species richness have associated with different mechanisms avoiding competition, such as spatiotemporal heterogeneity (weaker competitors may find a more favourable place or time) or environmental stress (competition is assumed to be less intensive under difficult conditions). More recently, large-scale process have been taken into account, raising such questions as: which plant species may potentially grow in a certain community? Are evolutionary processes and species dispersal responsible for the differences between communities? The species-pool theory attempts to answer these general questions, and information about species pools is needed for the design of experiments where the number of species in a community is manipulated.