Disentangling and ranking the influences of multiple environmental factors on plant and soil-dwelling arthropod assemblages in a river Rhine floodplain area

Floodplains of large rivers are among the most dynamic and diverse, yet most threatened ecosystems on earth. For a solid underpinning of river conservation and rehabilitation measures, it is critical to unravel the influences of the multiple stressors affecting floodplain ecosystems. Using canonical correspondence analysis with variance partitioning, we disentangled and ranked the influences of three floodplain ecosystem stressors (land use, flooding and soil contamination) on terrestrial plant and soil-dwelling arthropod assemblages in a floodplain area along the river Rhine in The Netherlands. We included five biotic assemblages: plant species (73 taxa), ground beetle species (57 taxa), ground beetle genera (29 taxa), beetle families (32 taxa) and arthropod groups at taxonomic levels from family to class (10 taxa). Plant and arthropod assemblages were primarily related to land use, which explained 19–30% of the variation in taxonomic composition. For plant species composition, flooding characteristics were nearly as important as land use. Soil metal contamination constituted a subordinate explanatory factor for the plant assemblages only (3% of variation explained). We conclude that the taxonomic composition of terrestrial plant and arthropod assemblages in our study area is related to land use and flooding rather than soil metal contamination.     

How did climate drying reduce ecosystem carbon storage in the forest–steppe ecotone? A case study in Inner Mongolia, China

The projected recession of forests in the forest–steppe ecotone under projected climate drying would restrict the carbon sink function of terrestrial ecosystems. Previous studies have shown that the forest–steppe ecotone in the southeastern Inner Mongolia Plateau originally resulted from climate drying and vegetation shifts during the mid- to late-Holocene, but the interrelated processes of changing soil carbon storage and vegetation and soil shifts remain unclear. A total of 44 forest soil profiles and 40 steppe soil profiles were excavated to determine soil carbon storage in deciduous broadleaf forests (DBF), coniferous forests (CF) and steppe (ST) in this area. Carbon density was estimated to be 106.51 t/hm² (DBF), 73.20 t/hm² (CF), and 28.14 t/hm² (ST) for these ecosystems. Soil organic carbon (SOC) content was negatively correlated with sand content (R = −0.879, P < 0.01, n = 42), and positively correlated with silt (R = 0.881, P < 0.01, n = 42) and clay (R = 0.858, P < 0.01, n = 42) content. Consistent trends between fractions of coarse sand and a proxy index of relative aridity in sediment sequences from two palaeo-lakes further imply that climate drying reduced SOC through coarsening of the soil texture in the forest–steppe ecotone. Changes in carbon storage caused by climate drying can be divided into two stages: (1) carbon storage of the ecosystem was reduced to 68.7%, mostly by soil coarsening when DBF were replaced by CF at ~5,900 ¹⁴C years before present (BP); and (2) carbon storage was reduced to 26.4%, mostly by vegetation shifts when CF were replaced by ST at ~2,900 ¹⁴C years BP.     

Soil Cyanobacterial and Microalgal Diversity in Dry Mountains of Ladakh,NW Himalaya,as Related to Site,Altitude, and Vegetation

Although phototrophic microbial communities are important components of soils in arid and semi-arid ecosystems around the world, the knowledge of their taxonomic composition and dependency on soil chemistry and vegetation is still fragmentary. We studied the abundance and the diversity of cyanobacteria and eukaryotic microalgae along altitudinal gradients (3,700–5,970 m) at four sites in the dry mountains of Ladakh (Little Tibet, Zanskar Mountains, and Eastern Karakoram), using epifluorescence. The effects of environmental factors (altitude, mountain range, and vegetation type) on soil physico-chemical parameters (pH; texture; organic matter, nitrogen, ammonia, and phosphorus contents; and concentration of chlorophylls and carotenoids) and on the composition and biovolume of phototrophs were tested by multivariate redundancy analysis and variance partitioning. Phototrophs were identified in all collected samples, and phototroph biovolume ranged from 0.08 to 0.32 mm³ g⁻¹ dry weight. The dominant component was cyanobacteria, which represented 70.9% to 98.6% of the biovolume. Cyanobacterial species richness was low in that only 28 morphotypes were detected. The biovolume of Oscillatoriales consisted mainly of Phormidium spp. and Microcoleus vaginatus. The environmental factors accounted for 43.8% of the total variability in microbial and soil data, 20.6% of which was explained solely by mountain range, 7.0% by altitude, and 8.4% by vegetation type. Oscillatoriales prevailed in alpine meadows (which had relatively high organic matter and fine soil texture), while Nostocales dominated in the subnival zone and screes. Eukaryotic microalgae together with cyanobacteria in the order Chroococcales were mostly present in the subnival zone. We conclude that the high elevation, semiarid, and arid soils in Ladakh are suitable habitats for microbial phototrophic communities and that the differences in these communities are associated with site, altitude, and vegetation type.     

A Robust Technique for Mapping Vegetation Condition Across a Major River System

Ecologists need to develop tools that allow characterization of vegetation condition over scales that are pertinent to species’ persistence and appropriate for management actions. Our study shows that stand condition can be mapped accurately over the floodplain of a major river system (ca 100,000 ha of forest over 1600 km of river)—the Murray River in southeastern Australia. It demonstrates the value of using quantitative ground surveys in conjunction with remotely sensed data to model vegetation condition over very large spatial domains. A comparison of four modelling methods found that stand condition was best modelled using the multivariate adaptive regression spline (MARS) method (R ² = 0.85), although there was little difference among the methods (R ² = 0.77–0.85). However, a subsequent validation survey of condition at new locations showed that use of artificial neural networks had substantially higher predictive power (R ² = 0.78) than the MARS model (R ² = 0.28). This discrepancy demonstrates the value of using several modelling approaches to determine relationships among vegetation responses and environmental variables, and stresses the importance of validating ecological models with predictive surveys conducted after model building. The artificial neural network was used to produce a stand condition map for the whole floodplain, which predicted that only 30% of the area containing Eucalyptus camaldulensis stands is currently in good condition. There is a downstream decline in stand condition, which is related to more extreme declines in flooding, due to water harvesting, and drier climate found in the Lower Murray region. Rigorous surveying and modelling approaches, such as those used here, are necessary if vegetation health is to be effectively monitored and managed. Author Contribution: SCC wrote the paper and was involved in all parts of the research; RM conceived and designed the study, and contributed to analysis and writing; JR designed the study, and contributed to writing; PJB designed the study and contributed to writing; MW contributed to design and modelling; JRT contributed to modelling; PG contributed new methods and modelling.     

Altitudinal changes in carbon storage of temperate forests on Mt Changbai, Northeast China

A number of studies have investigated regional and continental scale patterns of carbon (C) stocks in forest ecosystems; however, the altitudinal changes in C storage in different components (vegetation, detritus, and soil) of forest ecosystems remain poorly understood. In this study, we measured C stocks of vegetation, detritus, and soil of 22 forest plots along an altitudinal gradient of 700–2,000 m to quantify altitudinal changes in carbon storage of major forest ecosystems (Pinus koraiensis and broadleaf mixed forest, 700–1,100 m; Picea and Abies forest, 1,100–1,800 m; and Betula ermanii forest, 1,800–2,000 m) on Mt Changbai, Northeast China. Total ecosystem C density (carbon stock per hectare) averaged 237 t C ha⁻¹ (ranging from 112 to 338 t C ha⁻¹) across all the forest stands, of which 153 t C ha⁻¹ (52–245 t C ha⁻¹) was stored in vegetation biomass, 14 t C ha⁻¹ (2.2–48 t C ha⁻¹) in forest detritus (including standing dead trees, fallen trees, and floor material), and 70 t C ha⁻¹ (35–113 t C ha⁻¹) in soil organic matter (1-m depth). Among all the forest types, the lowest vegetation and total C density but the highest soil organic carbon (SOC) density occurred in Betula ermanii forest, whereas the highest detritus C density was observed in Picea and Abies forest. The C density of the three ecosystem components showed distinct altitudinal patterns: with increasing altitude, vegetation C density decreased significantly, detritus C density first increased and then decreased, and SOC density exhibited increasing but insignificant trends. The allocation of total ecosystem C to each component exhibited similar but more significant trends along the altitudinal gradient. Our results suggest that carbon storage and partitioning among different components in temperate forests on Mt Changbai vary greatly with forest type and altitude.     

Circadian and ultradian extrasystole rhythms in healthy individuals at elevated versus lowland altitudes

We defined chronobiologic norms for supraventricular and ventricular single extrasystoles (SV and VE, respectively) in healthy older males in lowland areas. The study was extended to higher altitudes, where hypobaric hypoxia was expected to increase extrasystole frequency, while perhaps not changing rhythmicity. In healthy men (lowland n = 37, altitude n = 22), aged 49–72 years, mean numbers of SVs and VEs were counted over a 24-h period. Cosinor regression was used to test the 24-h rhythm and its 2nd–10th harmonics. The resulting approximating function for either extrasystole type includes its point, 95% confidence interval of the mean, and 95% tolerance for single measurement estimates. Separate hourly differences (delta) between altitude and lowland (n = 59) were also analysed. Hourly means were significantly higher in the mountains versus lowland, by +0.8 beats/h on average for SVs, and by +0.9 beats/h for VEs. A relatively rich chronogram for VEs in mountains versus lowland exists. Delta VEs clearly display a 24-h component and its 2nd, 3rd, 4th and 7th harmonics. This results in significantly higher accumulation of VEs around 8.00 a.m., 11.00 a.m. and 3.00 p.m. in the mountains. The increase in extrasystole occurrence in the mountains is probably caused by higher hypobaric hypoxia and resulting sympathetic drive. Healthy men at elevated altitudes show circadian and several ultradian rhythms of single VEs dependent on the hypoxia level. This new methodological approach—evaluating the differences between two locations using delta values—promises to provide deeper insight into the occurrence of premature beats.     

The influence of water level and salinity on plant assemblages of a seasonally flooded Mediterranean wetland

We studied the key environmental variables shaping plant assemblages in Mediterranean abandoned ricefields with contrasting freshwater inputs over saline sediments. Plant species cover, water levels and soil variables were studied following a stratified random sampling design. Multivariate analysis identified water regime, particularly summer and autumn irrigation, as the most important environmental variable associated with vegetation composition. Distribution of annual and emergent macrophytes was not associated to salinity as found at the study site (0.57–4.1 mS/cm). Increased soil salinity, caused by summer irrigation near the soil surface did affect shallow-marsh assemblage distribution. These key environmental characteristics allowed us to identify six main assemblages. Annual macrophytes (such as Zannichellia palustris) were defined by high (over 10 cm) annual mean water level (MWL) and early successional conditions; emergent macrophytes (such as Typha spp., Scirpus lacustris) by annual MWL of 10 to − 25 cm and continuous shallow flooding in summer and autumn (MWL of 0–10 cm). The shallow-marsh group, correlated with annual MWL − 25 to − 100 cm, separated into two subgroups by salinity: grassland (including Paspalum distichum) with summer and autumn MWL below − 25 cm and brackish (with Juncus subulatus or Agrostis stolonifera) with summer and autumn MWL just below the soil surface (0 to − 25 cm). Water levels for the grassland subgroup may equate with a salinity ‘refuge’ for P. distichum. Time was a further determinant of variation in the full data set. Abundance of a large group of agricultural annuals (such as Sonchus tenerrimus) and damp ground annuals (including ricefield weeds such as Ammania robusta) decreased with time as bare ground disappeared. Maintenance of spatial vegetation heterogeneity in abandoned ricefields is contingent on continued water regime management.     

Long‐term fertilizer regimes have both direct and indirect effects on arthropod community composition and feeding guilds

Vegetation species composition and structure are known to affect taxonomic composition and life‐history characteristics of arthropod communities. Soil conditions alter vegetation composition and structure, and thus, soils have indirect effects on arthropods. Whilst grassland management affects soil properties, and hence vegetation, the direct effects of soil on arthropod communities within the sward are less clear. We used a long‐term hay meadow experiment to assess both direct and indirect effects of various fertilizer regimes on arthropod community composition and feeding guilds. Arthropods were sampled via pitfall traps and sweep nets and then analysed using principal components and redundancy analyses (RDA) to determine relationships between soil properties, vegetation community, forage quality and arthropod community. Vegetation community composition, measured by the first vegetation principal component, was used as a constraining variable in partial RDA, to estimate direct effects of soil on the arthropods. Variance partitioning quantified the relative roles of vegetation and soil on the arthropod community. Our results indicate that available soil nitrogen and carbon–nitrogen ratios are important determinants of arthropod community composition. Once the effects of the vegetation were removed, it was found the soil acidity and the available potassium altered arthropod community composition. Further research is required to determine the mechanisms by which these soil properties affect arthropod communities.     

Vertical distribution of female adults and larval offspring of the white grub <Emphasis Type="Italic">Dasylepida ishigakiensis</Emphasis> (Coleoptera: Scarabaeidae) in the soil of a sugarcane field on Miyako Island,Okinawa

To determine the depth of soil at which mated females of the white grub beetle Dasylepida ishigakiensis Niijima et Kinoshita oviposited and their larval offspring stayed in the soil in different seasons, 847 mated female and male adults were released into a caged sugarcane field on Miyako Island. We then excavated this field systematically to collect adults and their larval offspring in the soil once or twice per month from 24 April 2002 to 31 March 2003. Dead females were found between 10 and 50 cm deep in the soil (N = 91), but most frequently in the layer 30–40 cm deep (N = 42; 46.2%). They were recovered more frequently in the soil at the plant foot (N = 73; 80.2%) than in the furrows (N = 18; 19.8%). On the other hand, no male carcass was discovered either in the soil or on the ground surface. The number of larvae discovered in the soil per row was large on 30 April (N = 52.5) and on 5 June (N = 58.3), when they were at the first instar. It decreased rapidly thereafter until 21 August (N = 9.5), when they molted to the second instar, and remained at similar levels through to the following 31 March (N = 8.0), during which they were mostly at the third instar. The larvae were found at various soil depths ranging from 0 to 70 cm, but the majority were found between 10 and 30 cm deep. The last sampling on 31 March indicated that mature larvae moved to a deeper layer for estivation. These results suggested that physical control through rotary tillage before they move to the deeper layer may be effective.     

Structure, Pattern and Mechanisms of Formation of Seed Banks in Sand Dune Systems in Northeastern Inner Mongolia, China

A comparison of structure and pattern of the soil seed bank was made between active and stabilized sand dunes in northeastern Inner Mongolia, China. The objective of this paper was to determine the significance of seed bank in vegetation restoration of sand dunes. The results showed that (1) average seed density decreased from stabilized sand dune to interdune lowland of stabilized sand dune, to interdune lowland of active sand dune, and to active sand dune; (2) horizontally, along the transect from interdune lowland to ecotone and to sand dune top, a ‘V’ shaped pattern was presented in the active dune system, and a reverse ‘V’ shaped pattern in the stabilized sand dune system; (3) vertically, the proportion (accounting for the total seeds) of seeds found in 0–20 mm soil profile decreased from stabilized sand dune to interdune lowland of stabilized sand dune, to interdune lowland of active sand dune, and to active sand dune. The same order was also found in 20–50 mm and 50–100 mm soil profiles; (4) the Sokal and Sneath similarity indices in the species-composition between soil seed bank and above-ground vegetation were ranked as: the stabilized sand dune (24%) > the interdune lowland of active sand dune (21%) > the interdune lowland of stabilized sand dune (18%) > the active sand dune (5%); and (5) vegetation restoration of active sand dunes depends on the dispersal of seeds from nearby plant communities on the interdune lowlands. Much effort must be made to preserve the lowlands, as lowlands are the most important seed reservoir in the active sand dune field.     

Breeding biology of Montagu’s Harrier Circus pygargus in north-central Kazakhstan

The ecology and conservation status of Central Asian populations of Montagu’s Harriers Circus pygargus are poorly known. We studied the breeding biology of this species during 3 years in the Naurzum region, north-central Kazakhstan. Most Montagu’s Harriers in the study area nested in the forest-steppe transition area, in bushy areas dominated by dogrose Rosa canina, which was apparently the nesting vegetation type providing highest and densest nest cover in the study area. Laying occurred from 26 April to 7 June (average 13 May, n = 49) and, although it varied significantly between years, was earlier than in western European populations of similar latitude. Mean (±SD) clutch size was 4.44 ± 0.86 (range 2–6; n = 50), in the higher range observed for the species. There was no significant interannual variation in clutch size, despite large variations in the abundance of small mammals in the area. Diet was mainly composed of lizards (54.2%, n = 533 identified prey in all 3 years), with small mammals (17.1%), passerine birds (14.3%) and insects (13.6%) also being consumed. Mean brood size at the last visit was 2.55 ± 2.10 (range 0–6; n = 51). Failure rate was relatively high; the main identified cause of nest failure was predation. We compare the data obtained in this population breeding in natural steppes with breeding parameters from the well-studied western European populations, and discuss the implications for the conservation of this species.     

<Emphasis Type="Italic">Kazachstania intestinalis</Emphasis> sp. nov., an ascosporogenous yeast from the gut of passalid beetle <Emphasis Type="Italic">Odontotaenius disjunctus</Emphasis>

Three ascosporogenous yeast strains were isolated from the gut of the passalid beetle, Odontotaenius disjunctus, inhabiting on rotten oak trees. DNA sequence comparison and other taxonomic characteristics identified the strains as a novel species in the genus Kazachstania. The name Kazachstania intestinalis sp. nov. (type strain EH085^T = ATCC MYA-4658^T = CBS 11839^T) is proposed for the strains. The yeast is homothallic, producing persistent asci with 1–4 spheroidal ascospores. Molecular phylogeny from ribosomal RNA gene sequences placed this novel species on the basal lineage of a clade including Kazachstania lodderae, Kazachstania exigua, Kazachstania martiniae, and other related Kazachstania spp., but none of those species was a close sister to K. intestinalis.     

Incidence of Hemorrhagic Disease in White-Tailed Deer Is Associated with Winter and Summer Climatic Conditions

Hemorrhagic disease (HD) is an important vector-borne disease of white-tailed deer (Odocoileus virginianus). The objective of this study was to determine whether temperature and precipitation were associated with a measure of annual incidence of HD in white-tailed deer from Virginia. The annual percentages of deer with hoof wall growth interruptions (a clinical sign of HD) from four climate divisions in the HD endemic area of Virginia recorded during 1993–2006 were used as indicators of annual HD incidence. Pearson’s correlation coefficients between these indicators of incidence and average temperature (°F) or total precipitation (in.) for each month, as well as for winter (January–February), early summer (June–July), and late summer/fall (August–September–October) seasons were calculated. Strong direct correlations between the measure of annual HD incidence and average temperature for winter (r = 0.39, P = 0.003, n = 57), early summer (r = 0.51, P < 0.0001, n = 57), and late summer/fall (r = 0.42, P = 0.001, n = 57) were evident. There also was a strong inverse correlation between the measured annual HD incidence and June precipitation (r = −0.44, P = 0.0006, n = 57). Poisson regression models of seasonal temperatures and June precipitation to annual percentage of deer with hoof wall growth interruptions were developed. Based on Akaike’s Information Criterion with small sample size correction (AICc), the global model was selected as the top model. Higher winter and summer temperatures may increase vector capacity and competence, and lower precipitation in June may create favorable breeding sites for midges.     

Centric fusion polymorphism in captive animals of family Bovidae

Chromosomes of 228 captive specimens of the family Bovidae have been investigated. The examined animals were classified into the subfamilies Aepycerotinae, Reduncinae, Antilopinae, Alcelaphinae, Hippotraginae and Bovinae. Polymorphism for one fusion was identified in the species: Aepyceros melampus, 2n = 59–60; Redunca fulvorufula, 2n = 56–57; Kobus e. ellipsiprymnus, 2n = 50–52; Kobus e. defassa, 2n = 52–54 and Syncerus c. nanus, 2n = 54–55. This is the first study to reveal fusion 7;29 in Kobus e. defassa and simultaneously the respective polymorphism. Variation in the diploid number of chromosomes is also known in species: Oryx g. dammah and Oryx g. leucoryx but in this study only fusion 1;25 was identified in both karyotyped species. Our study showed that 13% of investigated individuals were polymorphic for the centric fusion and demonstrated the important role of cytogenetic screening in captive animals at zoological gardens.     

The ground beetles (Coleoptera: Carabidae) of exposed riverine sediments in Scotland and northern England

A survey of invertebrates on exposed riverine sediments (ERS) in four catchments of rivers in Scotland and northern England was carried out in 1996 and 1997 using pitfall traps. The resulting 179 lists of ground beetle species were used in ordination and classification analyses to determine the different types of habitats and the environmental factors influencing species assemblage distribution. Types of ERS habitat differed between highland and lowland catchments; there were also different numbers of habitat types in each catchment. The distribution of ERS within catchments was related to geology, position in catchment, sediment composition and the amount of vegetation. Evidence of the positive nature of river engineering was identified and the role of river management is discussed. The numbers of nationally rare and scarce ground beetle species recorded from the ERS habitats in each catchment are reported and the factors affecting their distribution discussed.     

Characteristics of Night Sleeping Trees of Proboscis Monkeys (<Emphasis Type="BoldItalic">Nasalis larvatus</Emphasis>) in Sabah,Malaysia

Primates spend about half of their lives at sleeping sites, and their choice of sleeping sites may affect individual survival. We identified a total of 88 trees used by proboscis monkeys (Nasalis larvatus) as night sleeping sites on 16 nights from June to September 2008 in riverine, mangrove, and mixed mangrove–riverine forests along the Garama River, a tributary of the Klias River, in the west of Sabah, Malaysia. We recorded 11 variables for each tree, including the species, physical structure, distance from the riverbank, and connectivity with surrounding trees. We compared sleeping trees with 114 trees with ≥30 cm girth at breast height (GBH) located ≤50 m of the riverbank in 8 botanical plots (total 1 ha). Trees in the plots represented the general vegetation patterns of the study area. Choice of sleeping trees did not depend on the tree species. Although sleeping trees included trees ≤46 m from the river, those closer to riverbanks (5–35 m, n = 76) were more likely to be used as sleeping sites. Compared to the available trees, sleeping trees had larger trunks (mean±SD = 143.6 ± 56.9 cm GBH), and were taller (mean±SD = 34.3 ± 8.1 m), with greater number (median = 6; range = 12) and larger (mean±SD = 24.1 ± 15.2 cm circumference) main branches. They were also located near to other trees, with overlapping branches, creating good arboreal connectivity. Choice of sleeping trees by proboscis monkeys is likely to be related to risks of predation and injury from falling, as well as ease of social interaction and efficiency of locomotion.     

Airborne Laser Scanning as a Tool for Lowland Floodplain Vegetation Monitoring

Monitoring of three-dimensional floodplain vegetation structure is essential for ecological studies, as well as for hydrodynamic modelling of rivers. Height and density of submerged vegetation and density of emergent vegetation are the key characteristics from which roughness parameters in hydraulic models are derived. Airborne laser scanning is a technique with broad applications in vegetation structure mapping, which therefore may be a promising tool in monitoring floodplain vegetation for river management applications. This paper first provides an introduction to the laser scanning technique, and reviews previous studies on the extraction of vegetation height and density of forests, low vegetation and meadows or unvegetated areas. Reliable predictions using laser scan data have been reported for forest height (R²=0.64–0.98), parameters related to forest density, such as stem number, stem diameter, biomass, timber volume or basal area (R²=0.42–0.93), and herbaceous vegetation height (summer condition; R²=0.75–0.89). No empirical relations have been reported on density of herbaceous vegetation. Laser data of meadows and unvegetated areas show too much noise to predict vegetation structure correctly. In a case study for the lower Rhine river, the potential of laser scan mapping of vegetation structure was further explored for winter conditions. Three laser-derived metrics that are often reported in the literature have been applied to characterize local vertical distributions of laser reflections. The laser data clearly show the large structural differences both between and within vegetation units that currently are the basis of floodplain vegetation and roughness mapping. The results indicate that airborne laser scanning is a promising technique for extraction of 3D-structure of floodplain vegetation in winter, except for meadows and unvegetated areas.     

Space use and habitat preferences of the invasive American mink (<Emphasis Type="Italic">Mustela vison</Emphasis>) in a Mediterranean area

Space use, intra-territorial habitat preferences, and factors affecting both were studied in an invading population of American mink, Mustela vison, in two rivers of a Mediterranean region of Spain. Average linear home range was 1.19 ± 0.73 km (±SD) and core area was 0.21 ± 0.08 km for resident males (n = 10); while for females (n = 5) they were 0.54 ± 0.14 and 0.19 ± 0.11 km, respectively. Overlapping between the home ranges of residents was low. In no case their core areas overlapped. Home ranges were small in comparison to other study areas and in general the resident minks were territorial. Linear home range length was related to individual weight and to the river. Weight had a positive effect indicating a potential body condition effect, while river may be showing a habitat quality effect. Habitat preferences were positively affected by the abundance of helophytic vegetation and negatively by the presence of human activity. Helophytic vegetation offers both food and refuges, while human activity may represent a potential danger. Percentage of captures was higher inside the core areas and was slightly influenced positively by abundance of helophytic vegetation. All this information should be considered when designing and implementing measures to control the expansion of American minks. We recommend keeping going with the trapping sessions but, given the results obtained, reducing the distance between traps down to 200 m to maximize capturability (i.e., about doubling the trapping effort), and, when available, placing them near helophytic vegetation. In the absence of helophytic vegetation, traps should be located near any kind of vegetation providing coverage for mink and far from human activity.     

Zinc in Postmortem Body Tissues and Fluids

Data on zinc concentration in the human body may be used to interpret the results obtained in cases of chronic and acute poisonings with zinc compounds, i.e., in clinical and forensic toxicology. In this paper, the concentrations of zinc in human tissues and body fluids obtained from autopsy cases concerning non-poisoned people (n = 203), aged from 14 to 80 years, between 1995 and 2008, are presented. The following values were found by the flame atomic absorption method (mean ± SD, median, range, in microgram per gram or microgram per milliliter): brain 10.3 ± 1.36, 10.2, 7.99–13.8 (n = 48); stomach 14.2 ± 3.63, 13.6, 8.00–22.5 (n = 71); intestines 15.7 ± 5.22, 15.8, 8.36–28.1 (n = 35); liver 39.6 ± 16.1, 36.6, 16.0–78.8 (n = 109); kidney 33.8 ± 10.1, 31.8, 16.4–60.9 (n = 93); lung 12.0 ± 3.88, 11.0, 6.13–18.7 (n = 26); spleen 14.7 ± 2.53, 14.6, 11.4–18.3 (n = 5); heart 26.5 ± 3.63, 26.7, 22.5–31.8 (n = 5); blood 6.81 ± 1.21, 7.00, 4.02–8.68 (n = 50); urine 0.69 ± 1.70, 0.60, 0.39–1.00 (n = 5), and bile 4.92 ± 1.64, 3.75, 3.20–7.09 (n = 9). The accuracy of the method was checked through the use of SRM Bovine Liver 1577b (certified: 127 ± 16 μg Zn/g, found: 117 ± 0.7 μg Zn/g (n = 6)).     

Soil erodibility,microbial biomass,and physical–chemical property changes during long-term natural vegetation restoration: a case study in the Loess Plateau,China

Soil erodibility (K factor) is an important index for measuring soil susceptibility to water erosion, and an essential parameter that is needed for the prediction of soil erosion. Field investigation and laboratory analysis were conducted to study the changes of soil characteristics during long-term vegetation restoration in the hilly gullied loess area. The soil erodibility K values were calculated using the EPIC model and the physico-chemical properties as well as microbial characteristics were evaluated along a chronosequence of natural vegetation recovery (0–50 years) in abandoned land in the Zhifanggou Watershed of Ansai County, northwestern Shaanxi Province, China. The results showed that natural vegetation recovery following abandonment resulted in improvement of the soil properties and structure and these improving effects were closely related to the date of abandonment. Specifically, the K value of the surface layer (0–20 cm) was significantly reduced with time, while the total organic carbon, total nitrogen and soil microbial biomass C, microbial N and microbial P and the water-stable aggregate increased quickly. During the first 10 years of abandonment, these changes occurred relatively quickly due to a significant increase in soil organic matter, after which they gradually fluctuated for approximately 20 years, reaching their uttermost or minimum levels finally. However, these values differed greatly under Platycladus orientalis forest, which suggests that soil rehabilitation is a long-term task that requires several generations to complete.