MASS DISPERSAL OF TERRESTRIAL ORGANISMS DURING FIRST FLUSH EVENTS IN A TEMPORARY STREAM

Temporary streams expand and contract seasonally, forming a complex mosaic of aquatic, amphibic and terrestrial habitats. We studied the terrestrial arthropod fauna at the surface of the dry river bed as well as the fauna of Coarse Particulate Organic Matter (CPOM) deposits 0, 5 and 10 days after first flush events (years 2004–2006) along the Pardiela stream (SE Portugal). During the dry period, large amounts of organic material accumulated at the surface of the dry bed, colonized by abundant terrestrial arthropods (mean density: 13.3 ± 15.29 Ind gDM (Dry Mass of CPOM)). Arthropod density peaked in fresh flood deposits (mean density: 35.8 ± 33.4 Ind g DM), and subsequently decreased within time. Concurrently, the relative composition of the arthropod community changed from Day 0 to Day 10. The present results demonstrated that the dry bed of temporary streams served as a major habitat for terrestrial arthropods. During the first flush events, a mass dispersal of terrestrial arthropods, rafting on floating CPOM, occurred, subsequently forming distinct deposits along the channel margin. These deposits may constitute critical habitats, refugia and food resources for local and regional terrestrial arthropod assemblage

Distribution of two Epomis species (Carabidae, Chlaeniini) in Israel, with notes on their habitat

The records of Epomis dejeani Dejean, 1831 and E. circumscriptus (Duftschmid, 1812) in Israel are summarized and their geographical distribution is described. The two Epomis species are mainly found in the northern and central parts of Israel, but also extend southward to the Central Negev region and Arava Valley. Museum records combined with the present survey data suggest a relatively wide albeit patchy distribution of Epomis in Israel. Whereas the records suggest that E. dejeani is relatively more abundant than E. circumscriptus in Israel, records for other regions in the Palaearctic Region suggest the opposite. However, at least in Italy, E. circumscriptus is rare and recommended for listing as a critically endangered species. In none of the surveys conducted in Israel over four consecutive years were the two species recorded from the same site. None of the habitat parameters examined (vicinity to a water body; soil moisture; vegetation cover; presence of amphibians, or soil type) revealed any prominent difference in habitat choice by the two species. Epomis larvae feed exclusively on amphibians, and indeed we found the beetles sharing their habitat with amphibians during the beetles’ breeding period. In conclusion, in the absence of either a physical barrier or any apparent habitat difference, the segregation of the species to different sites may be a case of sympatric species that do not occur at the same sites. To cite: Wizen, G., Drees, C. & Gasith, A. 2012. Distribution of two Epomis species (Carabidae, Chlaeniini) in Israel, with notes on their habitat. Israel Journal of Entomology 41–42: 95–106.

Agroekologisk analys av Maldivernas jordbrukssystem för att förbättra näringsämnen

An agroecological analysis with focus on nutrient management was carried out for the farming systems of Northern Maldives using ‘Peanut model’- agroecosystem analysis framework described by Bawden et al (1986). Even though much of the practices are similar throughout the country, the focus of the study was on the farming activities of inhabited islands in northern region. The main objective of the study was to carry out a system analysis to identify major agriculture practices with relation to nutrient management. Analyses were based on in-depth observations carried out at three case-study farms from three inhabited islands (Komandoo, Nolhivaram and Kaashidhoo) in the north. Additionally, 30 farmers from the region were interviewed using semi-structured interviews. Apart from that data was collected through group discussions, transect walks, stakeholder interviews, basic soil analysis and SAFA assessments were carried out at the case-study farm islands. Many poor practices were identified as part of the routine nutrient management operations such as fertilizer mixing, routine field burning, low nutrient recycling and heavy dependency on external inputs. Lack of knowledge on general agricultural practices, average age of farmers, poor focus on agri-sectoral development are some of the reasons identified in this study

Disturbance accumulation hampers fish assemblage recovery long after the worst mining spill in the Iberian Peninsula

The influence of environmental variables on native and exotic fish species richness and diversity was analysed 8 years after one of the most environmentally harmful toxic spills worldwide. Environment-diversity relationships were addressed on different scales, and values were also compared with those of six similar basins not affected by the spill, with the aim of determining whether this disturbance was still exerting an influence on the fish assemblage. Results showed higher native species richness in environments with low human influence, no reservoirs upstream, a large drainage area and coarse substrate reaches. For native fish, variables at both the catchment and site were equally relevant. Exotic fish were mainly favoured by site-scale factors such as valley width downstream from the reservoir, where the alteration of the river channel and accumulated disturbances give them an advantage vs native species. Overall, 8 years after the accident, richness and diversity of the Guadiamar fish assemblage seemed more affected by anthropogenic impacts than by the long-term influence of the toxic spill. This work highlights that the potentially synergic effects of anthropogenic factors must be taken into account when monitoring the long-term effects of pollution events

The protective nature of Chironomus luridus larval tubes against copper sulfate.

The objective of this study was to determine whether the tubes in which Chironomus larvae dwell protect them against chemical toxicants. A laboratory culture of an Israeli benthic midge, Chironomus luridus, was exposed to copper sulfate. Two conditions were tested in bioassay experiments: larvae within silt tubes and larvae without tubes. The non toxic, anionic, fluorescent dye, fluorescein, was used to examine the effect of sub-lethal copper sulfate concentrations on the permeability of cuticular, gill and gut epithelia of the chironomids. Increased cell permeability, which is the cause of cell damage, was reflected by an increase in fluorescence intensity. Following exposure to copper sulfate, higher fluorescence was found in different body compartments: midgut, hindgut, tracheal gills, fat body and muscles, and the Malpighian tubules. The effect was significantly higher in tube-free larvae when compared to silt tube dwelling larvae. We conclude that in addition to its other functions in feeding, respiration, and anti-predation shelter, the Chironomus luridus tube protects its inhabitant from toxins such as copper sulfate

First record of Epomis circumscriptus (Duftschmid, 1812) (Carabidae: Chlaeniini) from the eastern Dead Sea area, Jordan

Epomis circumscriptus (Duftschmid, 1812) attacking the Middle East tree frog is recorded from Moab, Jordan (eastern Dead Sea area) for the first time. This new record expands the known range of this species in the Middle East.   Cite as: Yanai, Z., Truskanov, N., Gasith, A. & Wizen, G. 2015. First record of Epomis circumscriptus (Duftschmid, 1812) (Carabidae: Chlaeniini) from the eastern Dead Sea area, Jordan. Israel Journal of Entomology 44–45: 1–4. DOI: 10.5281/zenodo.30322 urn:lsid:zoobank.org:pub:38810FF-7F2F-4848-9383-3EF3C0D9D31

Habitat-specific benthic metabolism in a Mediterranean-type intermittent stream

A modified flow-through chamber method was used to measure gross primary production (GPP), net primary production (NPP), community respiration (CR) and associated environmental variables in an intermittent Mediterranean-type stream in Southern Portugal. Three common types of in stream habitats were targeted: cobble (C), cobble covered with filamentous algae (C+A) and leaf litter (LL). NPP, GPP and CR differed significantly among all three habitats. GPP increased with chlorophyll a and, less strongly, with photosynthetic active radiation and, therefore, was highest in C+A habitat. The highest CR was in LL and its variation was best determined by ash-free dry mass (AFDM) of plant litter. Higher respiration in LL was related to heterotrophic activity and, to a lesser extent, to autotrophic respiration associated with periphyton. We observed a decrease of production efficiency of primary producers with AFDM in C+A and C habitats. Our results demonstrate that each habitat type should be considered as a discrete metabolic entity and that particular sets of environmental factors are responsible for habitat specific metabolic responses. Scaling up measurements from discrete habitat patches to the entire reach or stream should not be done by extrapolating the results of a single habitat type and will require quantification of habitat coverage, at the appropriate scale

Mediterranean-climate streams and rivers: geographically separated but ecologically comparable freshwater systems

Streams and rivers in mediterranean-climate regions (med-rivers in med-regions) are ecologically unique, with flow regimes reflecting precipitation patterns. Although timing of drying and flooding is predictable, seasonal and annual intensity of these events is not. Sequential flooding and drying, coupled with anthropogenic influences make these med-rivers among the most stressed riverine habitat worldwide. Med-rivers are hotspots for biodiversity in all med-regions. Species in med-rivers require different, often opposing adaptive mechanisms to survive drought and flood conditions or recover from them. Thus, metacommunities undergo seasonal differences, reflecting cycles of river fragmentation and connectivity, which also affect ecosystem functioning. River conservation and management is challenging, and trade-offs between environmental and human uses are complex, especially under future climate change scenarios. This overview of a Special Issue on med-rivers synthesizes information presented in 21 articles covering the five med-regions worldwide: Mediterranean Basin, coastal California, central Chile, Cape region of South Africa, and southwest and southern Australia. Research programs to increase basic knowledge in less-developed med-regions should be prioritized to achieve increased abilities to better manage med-rivers

Global Scale Variation in the Salinity Sensitivity of Riverine Macroinvertebrates: Eastern Australia, France, Israel and South Africa

Salinity is a key abiotic property of inland waters; it has a major influence on biotic communities and is affected by many natural and anthropogenic processes. Salinity of inland waters tends to increase with aridity, and biota of inland waters may have evolved greater salt tolerance in more arid regions. Here we compare the sensitivity of stream macroinvertebrate species to salinity from a relatively wet region in France (Lorraine and Brittany) to that in three relatively arid regions eastern Australia (Victoria, Queensland and Tasmania), South Africa (south-east of the Eastern Cape Province) and Israel using the identical experimental method in all locations. The species whose salinity tolerance was tested, were somewhat more salt tolerant in eastern Australia and South Africa than France, with those in Israel being intermediate. However, by far the greatest source of variation in species sensitivity was between taxonomic groups (Order and Class) and not between the regions. We used a bayesian statistical model to estimate the species sensitivity distributions (SSDs) for salinity in eastern Australia and France adjusting for the assemblages of species in these regions. The assemblage in France was slightly more salinity sensitive than that in eastern Australia. We therefore suggest that regional salinity sensitivity is therefore likely to depend most on the taxonomic composition of respective macroinvertebrate assemblages. On this basis it would be possible to screen rivers globally for risk from salinisation