地表蚂蚁在云南萨王纳地区植被恢复过程中的指示作用

为了查清地表蚂蚁在萨王纳地区人工植被恢复过程中的指示作用,采用陷阱法调查了云南省萨王纳地区人工林和自然植被地表蚂蚁多样性。(1)群落物种组成:采集蚂蚁40467头,隶属于5亚科19属47种。扁平虹臭蚁Iridomyrmes anceps是保护较好自然植被的常见种;而迈氏小家蚁Monomorium mayri是干扰较大的自然植被及多数人工林的常见种。(2)多度和α多样性:在人工林中,印楝林地表蚂蚁群落多度和α多样性最高,桉树林次之,新银合欢林最低。(3)群落相似性及β多样性:印楝林地表蚂蚁群落与自然植被灌草丛较接近,而其它人工林蚂蚁物种组成不相似;新银合欢林β多样性最高,βCs值在0.481—0.935;印楝林较低,βCs值在0.200—0.478。(4)相关性分析:地表蚂蚁群落物种丰富度S值及ACE值和草本植物群落S值及ACE值均正相关。印楝林和桉树林具有较高的α多样性,在当地生物多样性保护中具有积极意义;而新银合欢林是生境极度退化区域的重要植被恢复模式之一,这3种人工林对于萨王纳地区植被恢复具有重要作用。蚂蚁群落α多样性能够作为生物多样性的指示物,指示云南萨王纳地区植被恢复中生物多样性的状况。     

Long-Term Biomonitoring of Soil Contamination Using Poplar Trees: Accumulation of Trace Elements in Leaves and Fruits

Phytostabilization aims to immobilize soil contaminants using higher plants. The accumulation of trace elements in Populus alba leaves was monitored for 12 years after a mine spill. Concentrations of As and Pb significantly decreased, while concentrations of Cd and Zn did not significantly over time. Soil concentrations extracted by CaCl₂ were measured by ICP-OES and results of As and Pb were below the detection limit. Long-term biomonitoring of soil contamination using poplar leaves was proven to be better suited for the study of trace elements. Plants suitable for phytostabilization must also be able to survive and reproduce in contaminated soils. Concentrations of trace elements were also measured in P. alba fruiting catkins to determine the effect on its reproduction potential. Cadmium and Zn were found to accumulate in fruiting catkins, with the transfer coefficient for Cd significantly greater than Zn. It is possible for trace elements to translocate to seed, which presents a concern for seed germination, establishment and colonization. We conclude that white poplar is a suitable tree for long-term monitoring of soil contaminated with Cd and Zn, and for phytostabilization in riparian habitats, although some caution should be taken with the possible effects on the food web.

Supplemental materials are available for this article. Go to the publisher's online edition of International Journal of Phytoremediation to view the supplemental file.     

Environmental factors associated with the distribution of floodwater mosquito eggs in irrigated fields in Wrocław,Poland

A survey of distribution patterns of floodwater mosquito eggs related to environmental conditions such as moisture and plant associations was conducted by using soil samples from irrigated fields in Wroc?aw, Poland. Mosquito egg distribution was determined by repeatedly flooding the soil samples with aerated water at a temperature of 25° C. Under laboratory conditions, hatching in installments of Aedes caspius (Pallas) and Aedes vexans (Meigen) were commonly observed. The results show that ～75% of the larvae of Ae. caspius and Ae. vexans hatched after the first flooding under summer‐like conditions, whereas, following the second and third flooding, the numbers of hatched larvae were significantly lower. In our study, within one intermediate flooded field, a total of 66 plant species was identified and classified into six communities. All vegetation types were associated by varied egg densities and showed differences both in richness and Shannon‐Wiener diversity index as well as in ecological indices for moisture, soil reaction, and nutrient level. Small changes in elevation along the slope within the study area showed a large difference in the distribution of mosquito eggs. The highest average egg density was observed in zones with high occurrence of Phalaris arundinacea, usually prevalent in intermediate flooded and fertile areas. Knowledge of the indicators for the distribution of floodwater mosquito eggs in temporary breeding sites may be essential for organizing a successful, integrated mosquito control program with special regard to microbial control agents.     

GRACILARIA EDULIS (RHODOPHYTA) AS A BIOLOGICAL INDICATOR OF PULSED NUTRIENTS IN OLIGOTROPHIC WATERS

The response of the marine macroalga Gracilaria edulis (Gmelin) Silva to nutrient pulses of varying magnitude was investigated to test its applicability as a marine bioindicator at two oligotrophic locations. After exposure to nutrient pulses, algal amino acid, tissue nitrogen, and chlorophyll a content were assessed relative to algae incubated under control conditions (no nutrient enrichment). The smallest nutrient pulse involved a nutrient enrichment experiment conducted within a coral atoll, whereas two larger pulses resulted from sewage discharge to a tropical coastal bay. After exposure to the smallest nutrient pulse (10 × ambient), only changes in macroalgal amino acid concentration and composition were detected (mainly as increases in citrulline). At 100 × ambient concentrations, increases in tissue % nitrogen of the macroalgae were detected, in addition to responses in amino acids. Macroalgae exposed to the highest nutrient pulse (1000 × ambient) responded with increased chlorophyll a , tissue nitrogen, and amino acids within the three day incubation period. In contrast to these algal responses, analytical water sampling techniques failed to detect elevated nutrients when nutrient pulses were not occurring. The responses of this algal bioindicator to variable nutrient pulses may provide a useful tool for investigating the source and geographical extent of nutrients entering oligotrophic coastal waters.     

The search for common anthropogenic impacts on biodiversity: a global network

We introduce an initiative to assess and compare landscape changes related to human activities on a global scale, using a single group of invertebrates. The GLOBENET programme uses common field methodology (pitfall trapping), to appraise assemblages of ground beetles (Coleoptera, Carabidae) in visually-similar land-mosaics (urban-rural gradients). Carabids were selected as the focal taxon as they are sufficiently varied (both taxonomically and ecologically), abundant and sensitive to the environment. However, work on other taxa is comparable with the GLOBENET framework. The continuum of decreasing human pressure from city centres into the surrounding countryside was selected to represent human-caused disturbance for this initial stage of GLOBENET because these gradients can be found virtually all over the world. Through the broad-scale assessment envisioned in the GLOBENET programme, we seek to separate general, repeated effects on biodiversity from those that depend on local environments or particular biotic assemblages. Based on this understanding we aim to develop simple tools and protocols for assessing ecological effects of human-caused landscape changes, which could help to sustainably manage landscapes for biodiversity and for human requirements. For instance, the response of different functional groups of carabids to these landscape changes may help guide management practices. Further GLOBENET developments and information are available at our website: http://www.helsinki.fi/science/globenet/     

Arthropods as Bioindicators in Agroecosystems of Jiang Han Plain,Qianjiang City,Hubei China

Using sweeping nets and pitfall traps, arthropods on the soil surface and on vegetation were periodically surveyed in two villages on the Jiang Han Plain from April to September 1994. Statistical analysis of the resulting data delineated groups of bioindicators on vegetation and on the grounds that represent components of formulas for evaluating environmental quality in agroecosystems. These groups are (1) Coccinellidae and Chrysopidae (seasonally migrating predators factor); (2) Braconidae and Chalcidoidea (parasitic insects factor); (3) Araneae and Mantodea on vegetation and Araneae, Carabidae, Opiliones and Nitidulidae on the ground (carnivorous arthropods factor); and (4) Formicidae, Isopoda, and Chilopoda (soil-dwelling arthropods factor). The following resource pools were identified for the different model arthropods: woodlots for Araneae and Mantodea; field margins for Chrysopidae and Coccinellidae; hedgerows for Braconidae and Chalcidoidea; and low-input cropfields on the floodplains for epigeic carnivorous arthropods. Comparison of these insect groups in different rural landscape units demonstrated the importance of a mosaic rural landscape, including woodlots, rationally designed field margins, and cropland, for creating an ecologically favorable agricultural environment.     

Feeding preference as a main determinant of microscale patchiness among terrestrial nematodes

Soil biota are responsible for essential ecosystem services such as carbon storage, nutrient cycling and water retention. However, assessment of the condition of soil biota is hampered by an overwhelming level of diversity. With representatives in all trophic levels of the food web, nematode communities can be used as bioindicators. Accurate assessment of nematode assemblages requires insight into the distribution of specimens with distinct food preferences. With the availability of taxon‐specific quantitative PCR assays, distribution patterns of multiple nematode groups can be investigated simultaneously. Here, microscale patchiness of 45 nematode taxa was studied on 12 sampling sites (each with four adjacent microplots) located on arable fields or semi‐natural grasslands (‘system’), and on marine, river clay or sandy soils (‘soil type’). From each microplot, five composite samples were collected. Contrary to our expectations, an increase in the number of cores per composite sample did not result in more accurate measurements, and apparently the levels of microscale patchiness of the taxa are low compared to what has been reported for oligophagous plant‐parasites. System and soil type did not affect microscale distribution. To investigate the level of patchiness in more detail, detection probability (DP) and variability of abundances were calculated. Common and widespread bacterivorous and fungivorous taxa had DP ≥ 90%, confirming low level of microscale patchiness. With DPs of 40%–70%, predators and most omnivores showed degrees of local clustering. An overview of mean variabilities of abundances is presented that offers insight into how feeding preferences impact the microscale distribution both between and within trophic groups.     

A DNA barcode library for Germany′s mayflies,stoneflies and caddisflies (Ephemeroptera,Plecoptera and Trichoptera)

Mayflies, stoneflies and caddisflies (Ephemeroptera, Plecoptera and Trichoptera) are prominent representatives of aquatic macroinvertebrates, commonly used as indicator organisms for water quality and ecosystem assessments. However, unambiguous morphological identification of EPT species, especially their immature life stages, is a challenging, yet fundamental task. A comprehensive DNA barcode library based upon taxonomically well‐curated specimens is needed to overcome the problematic identification. Once available, this library will support the implementation of fast, cost‐efficient and reliable DNA‐based identifications and assessments of ecological status. This study represents a major step towards a DNA barcode reference library as it covers for two‐thirds of Germany's EPT species including 2,613 individuals belonging to 363 identified species. As such, it provides coverage for 38 of 44 families (86%) and practically all major bioindicator species. DNA barcode compliant sequences (≥500 bp) were recovered from 98.74% of the analysed specimens. Whereas most species (325, i.e., 89.53%) were unambiguously assigned to a single Barcode Index Number (BIN) by its COI sequence, 38 species (18 Ephemeroptera, nine Plecoptera and 11 Trichoptera) were assigned to a total of 89 BINs. Most of these additional BINs formed nearest neighbour clusters, reflecting the discrimination of geographical subclades of a currently recognized species. BIN sharing was uncommon, involving only two species pairs of Ephemeroptera. Interestingly, both maximum pairwise and nearest neighbour distances were substantially higher for Ephemeroptera compared to Plecoptera and Trichoptera, possibly indicating older speciation events, stronger positive selection or faster rate of molecular evolution.     

FUnaria mediterranea monstruositäten aus italien

Abstract

The aim of the present study is to demonstrate the value of some nitrophilous plants as bioindicators related to global warming. As a case study, the space–time dynamics of the populations of some nitrophilous and ruderal species have been investigated along the southern-central Adriatic side of the Italian Peninsula. These have been examined according to the range of their distribution areas, to their ecological needs, and to the availability of past data, which have then been related to the data on global warming across the same territories. The choice for this investigation was for nitrophilous species with a Mediterranean distribution – of the Stenomediterranean type – and for some recent entries into the local flora as alien species. The spread of these species occurs in areas with intense human activity, where they have exploited the conditions of the warmer niche, such that their presence and their spatial spread observed over time are clearly linked to global warming. For all of the species in question, rapid increases in the population numbers have been observed, along with a northward shift of their distribution areas. These changes correspond to the increase in average annual temperature as revealed by the thermometric measurements.     

Heavy metal distribution in zooplankton from Buenos Aires coastal waters (Argentina)

ABSTRACT

Total Zooplankton samples from Argentinian and Uruguayan Coastal Waters were analysed to determine their heavy metal contents. Zinc, copper, cadmium, iron, lead and manganese concentrations were measured using atomic absorption spectrophotometry and metal content distributions were geographically plotted. Except for cadmium, all the studied metals showed maximum values on the Uruguayan shores, and this was related not only to the location of the potential metal sources, but also to the hydrographical characteristics of the area. Finally, the suitability of zooplankton as an adequate biological indicator of heavy metal pollution in coastal environments is discussed.