Wind-dispersed seeds blur phylogeographic breaks:The complex evolutionary history of Populus lasiocarpa around the Sichuan BasinOA

The strength of phylogeographic breaks can vary among species in the same area despite being subject to the same geological and climate history due to differences in biological traits.Several important phylogeographic breaks exist around the Sichuan Basin in Southwest China but few studies have focused on wind-dispersed plants.Here,we investigated the phylogeographic patterns and the evolutionary history of Populus lasiocarpa,a wind-pollinated and wind-dispersed tree species with a circum-Sichua...     

Effects of fire disturbance on the soil physical and chemical properties and vegetation of Pinus massoniana forest in south subtropical area

A variety of studies on the impact of fire disturbance on ecosystems has shown that the physical and chemical properties of soil after fire disturbance change notably. Meanwhile, little is known about the effects of different fire intensities on the soil properties and vegetation after fire disturbance, especially in the south subtropical area. In this paper, we analyzed the soil physical and chemical properties, vegetation species and species diversity of fire center, fire edge (which was burned a year ago) and non-burned Pinus massoniana plantation in Gaoyao, Guangdong province, China. The results showed that the soil conductivity, water content, total nitrogen, total potassium, and available potassium content of fire center were significantly higher than those of the non-burned land, and pH was higher than that of fire edge, whereas the available nitrogen, total phosphorus and organic matter content were much lower, which were generally existed in 0–10 cm soil layer and 10–30 cm soil layer. Changes of the soil properties of fire edge were similar with those of fire center, but less significant, and seemed to be more complex. Effects of burning on the vegetation of fire disturbance plots were found to be notable, species number and average height of plants of fire disturbance plots were lower than those of the non-burned plots, a difference of species diversity and uniformity were also shown, and finally, the composition of plant community also changed, e.g., pioneer species such as D. dichotoma, etc., dominated, and drought-resistant plants, heat-resistant plants and positive plants increased after burning.     

Effects of fire disturbance on the soil physical and chemical properties and vegetation of Pinus massoniana forest in south subtropical area

A variety of studies on the impact of fire disturbance on ecosystems has shown that the physical and chemical properties of soil after fire disturbance change notably. Meanwhile, little is known about the effects of different fire intensities on the soil properties and vegetation after fire disturbance, especially in the south subtropical area. In this paper, we analyzed the soil physical and chemical properties, vegetation species and species diversity of fire center, fire edge (which was burned a year ago) and non-burned Pinus massoniana plantation in Gaoyao, Guangdong province, China. The results showed that the soil conductivity, water content, total nitrogen, total potassium, and available potassium content of fire center were significantly higher than those of the non-burned land, and pH was higher than that of fire edge, whereas the available nitrogen, total phosphorus and organic matter content were much lower, which were generally existed in 0–10 cm soil layer and 10–30 cm soil layer. Changes of the soil properties of fire edge were similar with those of fire center, but less significant, and seemed to be more complex. Effects of burning on the vegetation of fire disturbance plots were found to be notable, species number and average height of plants of fire disturbance plots were lower than those of the non-burned plots, a difference of species diversity and uniformity were also shown, and finally, the composition of plant community also changed, e.g., pioneer species such as D. dichotoma, etc., dominated, and drought-resistant plants, heat-resistant plants and positive plants increased after burning.     

Lack of Evidence for 3/4 Scaling of Metabolism in Terrestrial Plants

Scaling, as the translation of information across spatial, temporal, and organizational scales, is essential to predictions and understanding in all sciences and has become a central issue in ecology. A large body of theoretical and empirical evidence concerning allometric scaling in terrestrial individual plants and plant communities has been constructed around the fractal volume-filling theory of West, Brown, and Enquist （the WBE model）. One of the most thought-provoking findings has been that the metabolic rates of plants, like those of animals, scale with their size as a 3/4 power law. The earliest, single most-important study cited in support of the application of the WBE model to terrestrial plants claims that whole-plant resource use in terrestrial plants scales as the 3/4 power of total mass, as predicted by the WBE model. However, in the present study we show that empirical data actually do not support such a claim. More recent studies cited as evidence for 3/4 scaling also suffer from several statistical and data-related problems. Using a forest biomass dataset including 1 266 plots of 17 main forest types across China, we explored the scaling exponents between tree productivity and tree mass and found no universal value across forest stands. We conclude that there is not sufficient evidence to support the existence of a single constant scaling exponent for the metabolism-biomass relationship for terrestrial plants.     

Acartia tonsa (Сopepoda) in the Black and Caspian Seas: Review of its success and some lessons

The variety of aquatic nonindigenous animals in marine habitats worldwide includes more than 16 planktonic Copepoda species. Acartia tonsa is a very successful one, distributed in many seas. Its invasion into European seas was analyzed before (Brylinski,1981), but from that time A.tonsa extended its range in European aquatic habitats. The author describes the history of the A.tonsa invasion into the Ponto-Caspian basin as well as some misleading earlier publications. Morphologic differences between A.clausi and A.tonsa, the neglect of which led to the wrong identification, were examined. The data on A.tonsa and total copepod dynamics in the Sevastopol Bay during the period of 1976~1996 and the same data on the Caspian Sea since 1981 were analyzed. The average size of A.tonsa in new habitats decreased, and its relative density in the Black and Caspian Seas gradually increased.     

Genotoxicity biomarkers in aquatic bioindicators

Pollution of the aquatic environment is an ever-growing problem, as waters are the ultimate sink for the large number of xenobiotics from multiple sources. DNA damaging agents have a significant ecological relevance since they are implicated in many pathological processes and exert effects beyond that of individual being active through following generations. A large number of methods have been applied to evaluate genotoxic damage in different aquatic species. Comet assay, as method for de- tecting DNA alterations, and micronucleus test, as an index of chromosomal damage are the most widely applied and validated methods in field studies. These methods were applied in different vertebrate and invertebrate aquatic species, but only mollusk and fish species have been employed in routine biomonitoring programs. Mussels, due to their widely geographical distribution and the suitability for caging represent the bioindicator of choice in field studies. Mytilus species is the most used marine mussel. The use of fish is limited to specific geographic areas. The present review mainly focuses on the application of comet assay and micronucleus test in mussels. A number of biomonitoring studies in mussels, using comet assay or micronucleus test, revealed exposure to different classes of genotoxic compounds with a good discrimination power. The different evidence from the two as- says, reflects different biological mechanisms for the two genetic endpoints, DNA damage and chromosomal damage, suggesting their combined application in the field. Different endogenous and exogenous factors have been shown to modulate the genotoxic responses in mussels, acting as confounding factors in environmental monitoring. The use of standardized protocol for caging, sampling and genotoxity evaluation is critical in biomonitoring studies. The use of a multimarker approach coupling genotoxicity biomarkers with physiological and biochemical factors allows to have a complete picture of the environmental pollution [Current Zoology 60 （2）： 273-284, 2014].     

Applied Ethnobotany：Participatory Approach for Community Development and Conservation

Applied ethnobotany is a new subject in ethnobiological sciences referring to the transferring,reviving and cultivating ethnobotanical knowledge among different social groups within intra-and-inter-communities.Much research related to biodiversity in many countries is largely devoted to the gathering of more academic information,rather than to more incise studies focusing on finding answers to pressing challenges related to the use of plants by communities.China is country possessing rich biodiversity and cultural diversity.The long history of Chinese traditional medicine,diversity of cultivated crops and utilization of wild plant species are great cultural traditions to the country.Today,many societies of the country are still intricately linked to the natural environment economically as well as societies and groups within China.However,China is facing major changes in modernization of the coutry‘s economy,and globalization to form part of the world exchange system.Increasingly high levels of consumptions of natural plants,as well as national and international traes on plant products have resulted,space in over-harvesting of wild resources and accelerated environmental degradation.Local social structures and cultural traditions have also changed in order to cope with policy changes.In this background,over the last decade,applied ethnobotany for rural community development and conservation has been employed in different field projects and ethnic minority communities in Yunnan province of China.The applied ethnobotany has focused on work at community level to achieve sustainable use of naural resources and conservation.This presentation discusses findings and lessons learned from the projects on alternatives and innovations to shifting cultivation in Xishuangbanna,southwestern China.     

Denitrification in Aquatic Environments: A Cross-system Analysis

A meta-analysis was conducted on 136 data sets of denitrification rates (DR) recorded both during the period of highest water temperature and monthly in five types of aquatic ecosystems: oceans, coastal environments, estuaries, lakes and rivers. There was a gradual increase of DR from the ocean to rivers and lakes at both scales, with the rivers showing the highest DR variability. Denitrification peaked during summertime and showed highest seasonal variability in lakes and rivers. High concentrations of nitrate and interstitially-dissolved organic carbon as well as low oxygen concentration in the overlying water enhanced DR both during summer and at a seasonal scale whereas total phosphorus did at the seasonal scale only. There was a positive linear relationship between overlying nitrate and DR over the range of 1–970 μmol NO₃ (r ² = 0.86, P = 0.001). DR in lakes and rivers might reach values doubling those in the more denitrifying terrestrial ecosystems (e.g. agrosystems). Discrepancies in DR and its controlling factors between site-specific studies and this meta-analysis may arise from environmental variability at two, often confounded, scales of observation: the habitat and the ecosystem level. Future studies on denitrification in aquatic environments should address the topic of spatial heterogeneity more thoroughly.     

Sex-specific facilitation and reproduction of the gynodioecious cushion plant Arenaria polytrichoides on the Himalaya-Hengduan mountains,SW ChinaOA

When benefiting other beneficiaries, cushion plants may reciprocally receive feedback effects. The feedback effects on different sex morphs, however, remains unclear. In this study, taking the gynodioecious Arenaria polytrichiodes as a model species, we aimed to assess the sex-specific facilitation intensity of cushion plant by measuring the beneficiary cover ratio, and to assess the potential costs in cushion reproductive functions by measuring the flower and fruit cover ratios. The total benef...     

Insights into cryptic speciation of quillworts in ChinaOA

Cryptic species are commonly misidentified because of high morphological similarities to other species.One group of plants that may harbor large numbers of cryptic species is the quillworts(Iso?tes spp.),an ancient aquatic plant lineage.Although over 350 species of Iso?tes have been reported globally,only ten species have been recorded in China.The aim of this study is to better understand Iso?tes species diversity in China.For this purpose,we systematically explored the phylogeny and evolution ...     

Cell Wall Lignin is Polymerised by Class Ⅲ Secretable Plant Peroxidases in Norway Spruce

Class Ⅲ secretable plant peroxidases occur as a large family of genes in plants with many functions and probable redundancy. In this review we are concentrating on the evidence we have on the catalysis of lignin polymerization by class Ⅲ plant peroxidases present in the apoplastic space in the xylem of trees. Some evidence exists on the specificity of peroxidase isozymes in lignin polymerization through substrate specificity studies, from antisense mutants in tobacco and poplar and from tissue and cell cult...     

Azolla--a model organism for plant genomic studies

The aquatic ferns of the genus Azolla are nitrogen-fixing plants that have great potentials in agricultural production and environmental conservation. Azolla in many aspects is qualified to serve as a model organism for genomic studies because of its importance in agriculture, its unique position in plant evolution, its symbiotic relationship with the N2-fixing cyanobacterium, Anabaena azollae, and its moderate-sized genome. The goals of this genome project are not only to understand the biology of the Azolla genome to promote its applications in biological research and agriculture practice but also to gain critical insights about evolution of plant genomes. Together with the strategic and technical improvement as well as cost reduction of DNA sequencing, the deciphering of their genetic code is imminent.     

Geographic patterns of taxonomic and phylogenetic β-diversity of angiosperm genera in regional floras across the worldOA

Beta diversity(β-diversity) is the scalar between local(α) and regional(γ) diversity.Understanding geographic patterns of β-diversity is central to ecology,biogeography,and conservation biology.A full understanding of the origin and maintenance of geographic patterns of β-diversity requires exploring both taxonomic and phylogenetic β-diversity,as well as their respective turnover and nestedness components,and exploring phylogenetic p-diversity at different evolutionary depths.In this study,we ex...     

Distribution and conservation of near threatened plants in ChinaOA

Plants classified as Near Threatened(NT) are at high risk of becoming threatened because of anthropogenic interference and climate change.Especially in conservation efforts,such species have however long been overlooked.Here,we obtained 98,419 precise occurrence points for 2442 NT plants in China,and used species richness,species complementarity,and weighted endemism that consider all,endemic and narrow-ranged species in order to identify the diversity hotspots of NT plants.Then we evaluated the...     

Influence of rice black streaked dwarf virus on the ecological fitness of non-vector planthopper Nilaparvata lugens （Hemiptera： Delphacidae）

Rice black streak dwarf virus （RBSDV） is transmitted by the small brown planthopper （SBPH）, Laodelphax striatellus （Fallen）. Non-vector rice brown planthopper （BPH）, Nilaparvata lugens （Stal）, shares the same host rice plants with SBPH in paddy fields. The changes in nutritional composition of rice plants infected by RBSDV and the ecological fitness of BPH feeding on the infected plants were studied under both artificial climate chamber and field conditions. Contents of 16 detected amino acids and soluble sugar in RBSDV infected rice plants were higher than those in the healthy ones. On the diseased plants BPH had significantly higher nymphal survival rates, nymphal duration of the males, weight of the female adults, as well as egg hatchability compared to BPH being fed on healthy plants. However, there was no obvious difference in female nymph duration, longevity and fecundity. Defense enzymes （superoxidase dismutase, SOD and catalase, CAT） and detoxifying enzymes （carboxylesterase, CAE and glutathione S-transferase, GST） in BPH adults fed on diseased plants had markedly higher activities. The results indicate rice plants infected by RBSDV improved the ecological fitness of the brown planthopper, a serious pest but not a transmitter of the RBSDV virus.     

SEQUENCES OF LLANDOVERIAN CHITINOZOANS IN YANGZl REGION

This paper is dedicated as a token of homage and gratitude to Prof. Mu. En-zhi, the nestor in the field of graptolite studies, who introduced us chitinozoan studies with constant supports in many ways, and who died on 8th April, 1987. The Palaeontological Society of China has decided to publish a specieal volume in memory of this outstanding scientist.     

Melatonin: A master regulator of plant development and stress responses

Melatonin is a pleiotropic molecule with multiple functions in plants. Since the discovery of melatonin in plants, numerous studies have provided insight into the biosynthesis, catabolism, and physiological and biochemical functions of this important molecule. Here, we describe the biosynthesis of melatonin from tryptophan, as well as its various degradation pathways in plants. The identification of a putative melatonin receptor in plants has led to the hypothesis that melatonin is a hormone involved in regulating plant growth,aerial organ development, root morphology, and the floral transition. The universal antioxidant activity of melatonin and its role in preserving chlorophyll might explain its anti-senescence capacity in aging leaves. An impressive amount of research has focused on the role of melatonin in modulating postharvest fruit ripening by regulating the expression of ethylene-related genes.Recent evidence also indicated that melatonin functions in the plant's response to biotic stress,cooperating with other phytohormones and wellknown molecules such as reactive oxygen species and nitric oxide. Finally, great progress has been made towards understanding how melatonin alleviates the effects of various abiotic stresses, including salt, drought, extreme temperature, and heavy metal stress. Given its diverse roles, we propose that melatonin is a master regulator in plants.     

Effects of environmental factors on gross caloric values of three life-forms aquatic plants on the Qinghai-Xizang Plateau,China北大核心CSCD

Aims Gross caloric value (GCV) reflected plants' capability of converting solar energy. It provided a reliable indicator of plants' adaptations to environments in perspective of energy conversion and fixation. The aims of this study were (1) to illustrate the characteristics of GCV of aquatic plants on the Qinghai-Xizang Plateau, (2) to explore the geographical and environmental patterns and (3) to discuss the underlying mechanisms in forming the patterns. Methods In July and August 2015, we collected 533 samples of aquatic plants' leaves in 143 field sites on the Qinghai-Xizang Plateau, and measured their GCV using SDACM-4000 oxygen bomb calorimeter. Together with mean annual temperature (MAT) of climatic factor and properties of water body, this study compared the differences of GCV among submerged, emergent and floating-leaved plants by analysis of variance (ANOVA) and Tukey's HSD. We further regressed GCV of submerged and emergent plants against geographical and climatic factors and properties of water body by simple regression to explore the relative effects of environmental factors on GCV. Important findings On the Qinghai-Xizang Plateau, the mean GCV was (15.95 ± 3.90) kJ·g-1. Among the three life forms, the rank of GCV was the emergent plants (18.10 kJ·g-1) > the floating-leaved plants (16.77 kJ·g-1) > the submerged plants (14.31 kJ·g-1). With an increasing latitude, the GCV of emergent and submerged plants increased. Only GCV of emergent plants decreased with increasing altitude and temperature. The GCV of emergent and submerged plants increased with increased water salinity. Dissolved oxygen had significant negative effects on emergent plants, while pH value had no significant effects.