Clonal diversity and morphometry in the parthenogenetic earthworm Eiseniella tetraedra (Sav.) as affected by habitat characteristics including radioactive pollution

Eiseniella tetraedra (Sav.) is a cosmopolitan earthworm reproducing by obligate parthenogenesis. Here, we examined whether habitat characteristics affected the clone pool diversities and morphometric variability of the stenotopic riparian species E. tetraedra along a west–east transect from the Scandinavian mountains to lowland habitats of the Swedish east coast through Finland and to Russia (the Komi Republic) near the Ural Mountains. The transect comprised a geographical distance that cuts through the maritime to continental climatological zones within the boreal forest belt. It terminated in the Komi Republic, thus adding habitat (soil) characteristics to the factor of radioactive pollution. We found that mountain brooks in Sweden hosted the lowest numbers of clones, but in the lowland samples the clone pool diversities decreased in general from Sweden through Finland and Russia, i.e. from west to east. Nevertheless, high levels of clonal variability were observed within the countries, so that even monomorphic pools were found. However, no clones were shared between the countries. The fresh body weights and posterior body lengths of adult earthworms decreased from west to east. The numbers of posterior segments did not, however, differ between the countries, due to decreased segment size. The location of the clitellum, tubercula pubertatis and male pores showed no clear-cut morphometric clines along the W–E gradient, but the tubercula pubertatis and male pores were more clearly demarcated in adults of the Russian material than in those from the West. Eiseniella adults from the Swedish mountains carried spermatophores considerably more often than those from the other localities. E. tetraedra from localities with radioactive pollution in Russia (the Komi Republic) showed no clear-cut clone pool diversities in comparison to the clone pools of the other sites within the area. Monomorphic clone pools were recorded in localities with low as well as high levels of long-term ionizing radiation and exposure to heavy metals. We found no morphological malformations, such as dislocations of characters, in comparison to individuals from sites with lower levels of environmental radiation.     

Effects of acidification on the concentrations of heavy metals in running waters in Sweden

Heavy metals in running water are analysed within the Swedish Surface Water Monitoring Programme at about 80 stations. Data for selected rivers and brooks has been used to assess the effect of soil acidification on the concentrations of metals in waters. In southern Sweden, acidification shows a significant effect on Zn and Cd. In the upper parts of the drainage areas, there is an marked increased leakage of these metals from soils to waters indicated by elevated concentrations of Zn and Cd in brooks and also by high maxima during periods of low pH values. The increased leaching from forest soils also influences the concentrations in rivers in southern Sweden. During periods of high water flow, the pH values of the rivers decreases and the concentrations of Zn and Cd increases. At pH levels of 6.2–6.5 the concentrations of these metals are mostly 2–5 times higher as compared to pH levels of about 7.0. Since high concentrations of Zn and Cd coincides with high water flow, the transport of these metals has most certainly increased several times compared to the pre-industrial period. Hence, the by far most important human impact on the loading of Zn and Cd on the marine areas, surrounding southern Sweden is the increased leakage of these metals due to acidification. In northern Sweden the effects of acidification on Zn and Cd are less evident. In general, the concentrations of these metals are lower and the connection between pH and these metals are much less significant in the rivers. The links between acidification and the concentrations of Pb and Cu in the watercourses are comparatively much weaker. These two metals are more related to the content of organic matter in the waters and a possible effect of acidification is overshadowed by natural transport processes in soils and waters.     

A vagrant clone in a peregrine species: Phylogeography, high clonal diversity and geographical distribution in the earthworm Aporrectodea trapezoides (Dugès, 1828)

The peregrine lumbricid Aporrectodea trapezoides is originally from the Palaearctic region but is distributed worldwide. Little is known about its clonal diversity or the existence of a pattern of biogeographical diversification of clones. This study aimed to explore the evolutionary history of A. trapezoides by analysing the mitochondrial (COI and COII) and nuclear (28S rRNA and histone H3) DNA sequences of individuals collected in 11 different countries. High clonal diversity was found for this species, with thirty-seven clones clearly divided into two distinct lineages (I and II). The marked biogeographical boundary between these lineages corresponds to the line separating the Eurosiberian and Mediterranean climates in North Spain. Clone 1 was shared by one-third of the earthworms. While this clone was found in most of the sampled localities, the rest of the clones showed geographically-restricted distributions. This clone may have originated in the Mediterranean area of Central Spain. As it was obviously introduced in Australia and it was found in locations occupied by members of both lineages, we hypothesise that it may have also been introduced in other countries and that it could be a general-purpose genotype able to adapt to a wide range of niches.     

中国古代利用林草保持水土的思想与实践

 中国古代由于不合理的人为活动,森林植被遭受巨大破坏,水土流失严重发生,对社会造成极大危害。劳动人民在平治水土的实践中积累了丰富经验,尤其是在利用林草保持水土方面创造出许多有效措施。主要理论成果有山川为国家之本、森林能固土防灾、治水重在治山;实践经验为封山护林、荒山造林、堤防植树、草障住淤等。教训为:理论与实践脱节;重治水、轻治山,重工程措施、轻植物措施。     

Taxonomic status and intraspecific phylogeography of two sibling species of Metaphire (Oligochaeta: Megascolecidae) in Taiwan

In this study the synonymy of Amynthas formosae (Michaelsen, 1922) and A. yuhsii (Tsai, 1964) are reevaluated and the intraspecific phylogeography between them is studied. The morphological comparison and phylogenetic analysis based on cytochrome c oxidase subunit I suggest that A. formosae and A. yuhsii are not synonyms and both of them belong to Metaphire. The phylogeographic analysis suggests that the formation of mountains and rivers during the uplift of the Western Foothills in Taiwan comprised the vicariance events responsible for the intraspecific genetic differentiation between these two species.     

Variation in Elymus repens susceptibility to glyphosate

Continuous increase in glyphosate use in Sweden has caused concern about resistance development, not least in connection with the possible introduction of crops resistant to glyphosate. In Sweden, the main weed targeted by glyphosate is Elymus repens (L.) Gould. We sampled 69 clones of E. repens to assess the magnitude and geographical distribution of variation in susceptibility to glyphosate. Clones originated from four habitat types: intensively and extensively used arable lands, field vicinities and other habitats, including natural vegetation. Susceptibility varied greatly among clones with GR50 (50% of untreated growth reduction) spanning over at least one order of magnitude, 17–278 active ingredient ha^?1 in a pot experiment setting. There was a strong covariance between geographic and genetic distance, but there was no evidence of geographic or genetic differentiation in GR50. Nor did GR50 vary consistently between habitat types. We conclude that no indication of past selection was found towards the resistance to glyphosate in E. repens clones in Sweden. The great variability in susceptibility suggests that there might be a potential for such selection.     

Stochasticity dominates assembly processes of soil nematode metacommunities on three Asian mountains

Nematodes play an important role in ecosystems; however, very little is known about their assembly processes and the factors influencing them. We studied nematode communities in bulk soils from three Asian mountain ecosystems to determine the assembly processes of free-living nematode metacommunities and their driving factors. On each mountain, elevations span a range of climatic conditions with the potential to reveal assembly processes that predominate across multiple biomes. A phylogenetic nu...     

Development of a monoclonal antibody-based enzyme-linked immuosorbent assay for the beta-adrenergic agonist zilpaterol

Zilpaterol is a beta-adrenergic agonist approved for use as a growth promoter in cattle in South Africa and Mexico but not in the European Union, United States, or Asia. Here, we report the development of a monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) for zilpaterol. Mice immunized with zilpaterol-butyrate-keyhole limpet hemocyanin were utilized for monoclonal antibody generation whereas zilpaterol-butyrate-bovine serum albumin was used as a coating antigen for ELISA. Thirteen clones were isolated, and after the initial sensitivity and isotyping experiments, three clones were selected for further ELISA optimization. Studies indicated that the optimum pH was near 7.4. Clone 3H5 had the highest sensitivity to zilpaterol and some interaction with clenbuterol and terbutaline at high concentrations but not other N-alkyl [bamethane, (-)-isoproterenol, (+)-isoproterenol, metaproterenol, or salbutamol] or N-arylalkyl (fenoterol, isoxsuprine, ractopamine, or salmeterol) beta-agonists tested. However, clone 3H5 was not functional at high salt concentrations, which precluded further development for urine analysis. Clone 2E10 showed increased sensitivity as salt concentrations were increased and did not cross-react with any of the structural analogues tested. However, its sensitivity to salt and urine concentration changes could cause high variability. Clone 7A8 showed good sensitivity and only a modest change with the salt concentration changes. Clone 7A8 also demonstrated smaller changes in IC(50) and B(0) with increasing sheep urine or cattle urine concentrations as compared to clones 2E10 or 3H5 and, thus, was selected for further development. The IC(50) for all of the antibodies showed exponential increases with increasing organic solvents concentrations, making it desirable to minimize solvent levels. In conclusion, a sensitive, specific zilpaterol monoclonal antibody-based ELISA has been developed that can serve as a rapid screening assay.     

Altitude-related changes in the mesofauna structure in soils of the Ethiopian plateau

Ecological-faunistic investigations of the mesofauna were carried out in mountain soils of Ethiopia for the first time. A comparative assessment of the group composition and the structural parameters of soil invertebrate communities was accomplished in a series of mountain habitats on the slopes of an extinct volcano in the altitude range of 1800 to 3200 m a.s.l. Some regularities of the altitudinal changes in the abundance of invertebrates were found: a maximum in a forest on the volcano slope, a trend of reducing their number and mass with altitude, and the minimal abundance of invertebrates in the soils under the forest and on the slope of the volcano crater. In contrast to the mountain systems of southern Europe and Asia, the animal population on the Ethiopian Plateau in the lower positions of the mountain catena was dominated by the forms dwelling on the soil surface; in the forest belt and high mountains, the inhabitants of mineral horizons prevailed. Specific features of the functional structure of the animal population in the soil under the crater forest are its relations to open habitats. At the same time, the absence of faunistic exchange with the adjacent ecosystem of the alpine meadow allows suggesting that the soil animal communities in the crater and on the external volcano slopes were formed independently from one another.     

长江上游及西南诸河区水土流失现状与综合治理对策

长江上游及西南诸河区横跨我国地貌第1级台阶和第2级台阶,地形起伏显著,构造运动强烈,降雨集中,人类活动强度大,水土流失发育,侵蚀类型多样。该区水土流失的特点有：坡耕地分布广泛,侵蚀强烈,是水土流失的主要来源;泥石流、滑坡量大面广,活动频繁,威胁工程与公共安全;库区水土流失普遍发育,面源污染严重,威胁水库水质;江河源区冻融、水力、风力侵蚀交互作用,草地退化严重,降低生态功能;石漠化过程加剧,危及土地安全,导致区域贫困;工程建设规模巨大,侵蚀产沙剧烈,成为新增水土流失的重要因素。针对该区水土流失的特点,提出如下治理对策：进行以坡改梯和坡面水系建设为主的坡耕地综合整治;重点治理泥石流和滑坡,控制沟谷蚀;建设清洁小流域,综合控制面源污染;改良牧业生产方式,保护草地,修复生态;开展石漠化综合防治,抢救性保护土壤资源;加强水土保持预防监督,落实工程建设水土保持,有效减轻工程建设产生的水土流失。     

Ploidy determination of some yam species (Dioscorea spp.) by flow cytometry and conventional chromosomes counting

Chromosomes counting and flow cytometry were used for assessing the ploidy level of various yam accessions of the INRA collection located in Guadeloupe. About 85 different clones were evaluated in the D. alata and D. cayenensis-rotundata and four other wild species related to D. cayenensis-rotundata. All the studied clones fitted in 4x, 6x and 8x ploidy levels. No diploid clone was found. Chromosomes counts and flow cytometry data led to the same results. The flow cytometry histograms for D. cayenensis-rotundata were not separated from those of its related wild species. Polyploidisation by fusion of 2n+n gamets was found to be unlikely for the two species D. cayenensis-rotundata and D. alata. Moreover, these results lead to the conclusion that the D. cayenensis-rotundata cultigens and the wild species analysed in this study may belong to the same gene pool.     

Comparative FT-Raman spectroscopy of Xanthoria lichen-substratum systems from temperate and antarctic habitats

Lichens have a primary role in the biodeterioration of rock substrata and in soil formation. In extreme Antarctic rock-face habitats, their exposed epilithic growth form makes them vulnerable to environmental stress, especially to increased UVB radiation within the late winter ozone “hole”. In this study, FT-Raman spectra of intact epilithic samples of the highly-pigmented lichen species Xanthoria elegans and Xanthoria mawsonii from a continental Antarctic habitat in central Victoria Land and Xanthoria parietina from a maritime temperate location in Scotland have been compared. Vibrational assignments have been made for their pigments, based on parietin and an anthraquinone model. Other significant spectral features are assigned to biodegradative secondary metabolites, cellulose and incorporated substratal rock particles. Differential distribution of parietin pigment bands in the profile of an X. elegans thallus is probably related to the high intensity of UV-radiation reaching its Antarctic cold desert surface environment. The significant differences in Raman spectra between epiphytic X. mawsonii and epilithic X. elegans at the same site possibly indicate different biochemical UV survival strategies. In contrast to spectra from other lichen species studied in our laboratories, the Xanthoria encrustations contain very little calcium oxalate, formed by reaction of oxalic acid with calcareous substrata. The 462 cm⁻¹ ν(SiO) band of quartz is found in the Raman spectra from both upper and lower surfaces of the lichen encrustations, confirms the physical incorporation of the substratum into the thallus.     

Correlations among species distributions, human density and human infrastructure across the high biodiversity tropical mountains of Africa

This paper explores whether spatial variation in the biodiversity values of vertebrates and plants (species richness, range-size rarity and number or proportion of IUCN Red Listed threatened species) of three African tropical mountain ranges (Eastern Arc, Albertine Rift and Cameroon-Nigeria mountains within the Biafran Forests and Highlands) co-vary with proxy measures of threat (human population density and human infrastructure). We find that species richness, range-size rarity, and threatened species scores are all significantly higher in these three tropical African mountain ranges than across the rest of sub-Saharan Africa. When compared with the rest of sub-Saharan Africa, human population density is only significantly higher in the Albertine Rift mountains, whereas human infrastructure is only significantly higher in the Albertine Rift and the Cameroon-Nigeria mountains. Statistically there are strong positive correlations between human density and species richness, endemism and density or proportion of threatened species across the three tropical African mountain ranges, and all of sub-Saharan Africa. Kendall partial rank-order correlation shows that across the African tropical mountains human population density, but not human infrastructure, best correlates with biodiversity values. This is not the case across all of sub-Saharan Africa where human density and human infrastructure both correlate almost equally well with biodiversity values. The primary conservation challenge in the African tropical mountains is a fairly dense and poor rural population that is reliant on farming for their livelihood. Conservation strategies have to address agricultural production and expansion, in some cases across the boundaries and into existing reserves. Strategies also have to maintain, or finalise, an adequate protected area network. Such strategies cannot be implemented in conflict with the local population, but have to find ways to provide benefits to the people living adjacent to the remaining forested areas, in return for their assistance in conserving the forest habitats, their biodiversity, and their ecosystem functions.     

Non-alluvial wetlands of the Southern Blue Ridge — Diversity in a threatened ecosystem

The generally steep landscape of the Southern Blue Ridge is not conducive to the formation of extensive wetlands, but wetlands do occur. Wetlands in this region are mostly small in size (< 10 ha), and are found in locations where topography is unusually gentle or where seepage is unusually strong or constant. Despite their rarity and small size, such wetlands show great species and community diversity, and are one of the most important habitats for rare (endemic and disjunct) plants and animals in the region. Community species composition seems to vary primarily in relation to elevation, topographic position, hydrology, underlying bedrock composition, recent land use, and biogeographic history. Based on differences hi vegetation structure and composition, landscape position, and hydrology, we recognize nine groups of non-alluvial wetlands in the Southern Blue Ridge. An inventory of non-alluvial wetlands in the mountains of North Carolina revealed that the majority of these naturally rare communities are now destroyed or severely altered. Bogs and fens of the North Carolina mountains have been reduced nearly six-fold from an original extent of about 2000 ha, so that only about 300 ha remain in reasonably intact condition, and most of the remnants are compromised by hydrologic alteration and nutrient inputs. Because wetlands tend to be concentrated in valley bottoms and at low elevations where most land is privately owned, efforts to assure their long-term viability will require innovative protection and restoration tools.     

Episodic Events in Water Chemistry and Metals in Streams in Northern Sweden during Spring Flood

Thirteen streams in the province of Jämtland in northern Sweden were monitored during spring in 1995 (December 94 – July 95) to study changes in water chemistry and metal concentrations during snow melt. The brooks are not treated with lime, with one exception, and can be approximately divided into three groups according to watershed characteristics; A) > 65% above tree line, B) > 65 % wetland, C) > 55% forested. During peak flow, pH dropped 0.5–2.5 units and alkalinity generally to zero. The brooks above tree line were lowest in base cations and reached the lowest pH-values (4.4–4.6) during peak flow, while sulphate levels were about the same as in the forested watersheds. During peak flow, organic anions showed the highest increase in the wetland and forested catchments. Compared to base flow, Al, Zn, Pb and to some extent Mn was enriched during peak flow. The results also illustrate the difficulties in generalising the reasons for alkalinity losses during spring flood in this kind of streams. In some of the brooks, the use of either base cations or silica, when calculating dilution effects, gave deviating results concerning the relative contribution of strong acids in the snow pack.     

典型喀斯特山地城市镶嵌山体斑块格局时空变化特征

喀斯特山地城市镶嵌山体对生物多样性保护、生态系统健康稳定、生态系统服务具有重要的作用和功能。为探明喀斯特山地城市镶嵌山体斑块的时空变化,以典型喀斯特山地城市贵阳市中心城区为对象,运用2000—2020年5期高分辨率遥感影像,采用GIS空间分析、探索性空间数据模型、景观格局分析等方法,从规模、形态和空间分布方面,分析了快速城市化背景下山体斑块格局的时空变化特征。结果表明:(1)贵阳市中心城区山体斑块数量和面积分布广泛,但20年间山体斑块数量减少30座,面积减幅达25.2%,表现出先切割打碎后吞并侵占的特征,其中大型山体规模持续减小,其他各类型山体数量和面积呈“先增后减”的变化趋势。(2)山体斑块分维数接近1,整体形状较为规则,2000—2020年山体斑块形状指数增大近1.12倍,斑块形状总体呈现复杂化、破碎化的趋势; 但大型、中大型山体斑块形状更加规则化,而其他类型山体斑块形状日趋复杂破碎。(3)山体斑块具有极显著的空间聚集效应,最邻近指数介于0.766 9～0.841 4,全局性空间聚类标准化Z值小于-2.58,以小面积山体斑块的聚集为主,分布具有明显的空间异质性。20年间,空间聚集效应减弱,高密度区逐渐萎缩,低密度区不断扩散且呈集中连片趋势; 并且山体斑块的潜在生态连通性水平持续降低。     

Soil zonality of the Chukotka Upland

The vertical soil-geographic zonality of the Chukotka Upland in the area of the Amguema River valley can be considered a model vertical zonality in the Low Arctic regions at the interface between the continental and oceanic climates. The plain bottom of the valley has a continental climate. The surrounding mountains are under the influence of an oceanic climate, which is more pronounced in the low mountains and less pronounced in the medium-high mountains. Three altitudinal soil zones are distinguished: (1) the plain Subarctic zone with the absolute heights below 200–400 m a.s.l., where cryoturbated humus-impregnated peat-mucky gleyzems are developed from loamy substrates, and gleyed soddy podburs are developed from loamy sandy substrates; (2) the low-mountain zone of a creeping alder forest (the forest-tundra zone?) of the Low Arctic at the heights of 400–700 m a.s.l., where mucky-gray-humus humus-impregnated podzolized gleyzems are developed under tundra patches, cryoturbated peat-mucky high-humus-impregnated podzolized gleyzems are developed under creeping alder thickets, and pedoliths are exposed in the zones of landslides; and (3) the mountain Middle Arctic zone at elevations above 700 m a.s.l., where very thin soil films predominate; gray-humus cryometamorphic lithozems are developed from the eluvium of magmatic rocks, and humus-impregnated cryometamorphic soils with quicksand suprapermafrost horizons are developed from the eluvium of hard sedimentary rocks.     

Foliar applied harpin effects on fruit quality of peppers

Abstract

During the past century, changes in cropping systems have led to selective pressure on weed flora. The number of competitive species with decreased susceptibility to herbicides has increased, at the cost of more susceptible species. For a long period, the economically important perennial weed species Cirsium arvense (L.) Scop. and Sonchus arvensis L. have mainly been controlled by the herbicide MCPA (phenoxy-acetic acid), which stimulates the weed plant to abnormal growth. However, it has been reported from Sweden, Great Britain, Hungary and North America that C. arvense has become less susceptible to MCPA since the 1950s. Therefore, two greenhouse experiments were performed at Uppsala, Sweden with clones of C. arvense and S. arvensis. The purpose was to study whether ecotypes (clones) from high input farmland, where herbicides had been used intensively and regularly for a long time, were less susceptible to herbicide (MCPA) treatment than ecotypes from low input farmland. Sixty clones of C. arvense and 36 clones of S. arvensis were treated with nine different doses of MCPA. The results supported the suggestion that a shift towards less MCPA-susceptible ecotypes of C. arvense had occurred on high input farmland. Clone material from such farmland had, on average, significantly higher dry matter content after herbicide treatment than ecotypes from low input farmland. Similar decrease in susceptibility was not detected for S. arvensis. This was probably due to S. arvensis generally being less susceptible to MCPA than C. arvense. Sonchus arvensis has therefore being exposed to a lower selection pressure than C. arvense.     

子牙河水系滨岸带植物群落结构及其与环境的关系

[目的]以海河流域子牙河水系河流滨岸带植物为对象,研究影响植物群落结构和分布格局的主要环境因子,为相关研究提供依据。[方法]2013年6月,在子牙河水系干支流设置了94个滨岸带样地,调查植被结构和海拔、护岸类型、堤外土地利用类型等6个环境因子。[结果]子牙河水系滨岸带植物共249种,分属于51科,166属。山区河段滨岸带有199种植物,分属于43科,135属,优势物种有芦苇(Phragmites australis)、蒙古蒿(Artemisia mongolica)、荆条(Vitex negundo)、黄花蒿(Artemisia annua)等;平原河段滨岸带有36种植物,分属于22科35属,优势物种主要有芦苇(P.australis)、反枝苋(Amaranthus retroflexus)等,山区植物丰富度明显高于平原区。[结论]海拔高度和堤外土地利用类型与植物群落结构显著相关。水热条件和人类活动压力是影响植被构成的主要成因。