Elisabeth I. Meyer

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 August 2009-30 September 2009

This article documents the addition of 229 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Acacia auriculiformis × Acacia mangium hybrid, Alabama argillacea, Anoplopoma fimbria, Aplochiton zebra, Brevicoryne brassicae, Bruguiera gymnorhiza, Bucorvus leadbeateri, Delphacodes detecta, Tumidagena minuta, Dictyostelium giganteum, Echinogammarus berilloni, Epimedium sagittatum, Fraxinus excelsior, Labeo chrysophekadion, Oncorhynchus clarki lewisi, Paratrechina longicornis, Phaeocystis antarctica, Pinus roxburghii and Potamilus capax. These loci were cross‐tested on the following species: Acacia peregrinalis, Acacia crassicarpa, Bruguiera cylindrica, Delphacodes detecta, Tumidagena minuta, Dictyostelium macrocephalum, Dictyostelium discoideum, Dictyostelium purpureum, Dictyostelium mucoroides, Dictyostelium rosarium, Polysphondylium pallidum, Epimedium brevicornum, Epimedium koreanum, Epimedium pubescens, Epimedium wushanese and Fraxinus angustifolia.

Breakdown rates of wood in streams

Abstract The breakdown rates of natural branch wood were studied in 2 streams (lowland and upland), and the current knowledge on breakdown rates of wood in streams was reviewed. The breakdown coefficient of natural alder branches, k = 0.0650/y, in an unpolluted upland stream corresponded well to the few published data on breakdown rates of natural wood substrates in streams. Breakdown rates of Scots pine (Pinus sylvestris, k = 0.0698/y), bark-covered black alder (Alnus glutinosa, k = 0.0859/y), and debarked black alder branches (k = 0.0717/y) in a nutrient-rich sandy lowland stream indicated that breakdown rates differ among tree species. Data from the present and previous studies on the breakdown of natural wood and commercial wood products (wood veneer, tongue depressors, ice-cream sticks) showed that breakdown is slower for natural wood than for commercial wood products, in part because the commercial wood products used in the studies had high surface to volume ratios. A strong relationship exists between surface to volume ratio of the substrate and breakdown rates. The breakdown rates of wood in streams were associated with several abiotic factors, including the physical and chemical properties of the wood substrates used, dissolved nutrients, and water temperature. Overall, the review of published breakdown rates emphasized that the current knowledge on the breakdown rates of wood in streams, especially the temporal patterns of microbial activities, is very limited, and heterogeneous experimental designs in previous studies prevent general conclusions. Nevertheless, measuring wood breakdown rates could be a promising tool for practical application in assessment of the ecological integrity of streams.

Discharge regime and the effect of drying on macroinvertebrate communities in a temporary karst stream in East Westphalia (Germany)

Abstract: The special hydrological situation of temporary streams has a great influence on the abiotic processes and other habitat conditions for organisms. To monitor possible impacts of stream drying on the composition of lotic communities, streamflow measurements and collections of the macrozoobenthos were conducted in a temporary and an adjacent upstream permanent section of the karst stream Sauer (East Westphalia, Germany) in 1996. The Sauer has a summer-dry temporary flow regime. The seasonal dry phase can last from spring to early autumn, so the duration of the dry phase varies from one to several months, increasing with distance downstream from the upstream permanent section. The number of invertebrate taxa and individuals decreases with increasing duration of the dry phase. The permanent section is characterized by taxa typical of montane and submontane streams, whereas the fauna of the temporary section is quite different, composed of representatives of various zonal areas. Limnephilid caddisflies are particularly characteristic of this section. Life cycle strategies and specific adaptations with respect to habitat drying are discussed for several species. It can be concluded that the temporary discharge regime of the karst stream Sauer has a clear effect on the invertebrate communities. They mainly consist of species which can be seen as characteristic faunal elements of temporary streams.

Lotic communities of two small temporary karstic stream systems (East Westphalia, Germany) along a longitudinal gradient of hydrological intermittency

Abstract The spatial and temporal discharge regime and its effects on benthic communities were studied in two small temporary karstic stream systems of the Paderborner Hochflache (East Westphalia, Germany). Both streams are characterized by very small perennial springbrook sections. Benthic invertebrates were sampled three times at 12 sites and discharge was measured monthly from March to September 2000. The spatial extension of streamflow was observed regularly to evaluate the duration of drought. Both streams showed a longitudinal gradient of hydrological intermittency from very small perennial reaches with low intermittency to an extremely harsh hydrological situation. The benthic communities displayed a decreasing species richness at increasing intermittency. The different hydrological stream sections were colonized by different lotic communities, characterized by typical species of temporary streams and by several typical species of springs. Particularly the perennial springs and springbrooks are very important for the species richness in these karstic stream systems.

A sandy hyporheic zone limited vertically by a solid boundary

Knowledge on sandy hyporheic zones in streams, especially those limited by a solid layer, is scarce. We studied seasonal and spatial patterns of abiotic parameters in the hyporheic zone of a lowland stream, in which the depth of the sandy sediment is limited by a layer of iron pan, a cemented and firm Fe- and Mn-rich horizon that hinders exchange between stream/interstitial water and ground water Temperature, dissolved organic carbon, particulate organic matter, phosphorus, and nitrogen compounds in the interstitial water reflected the conditions of the infiltrating channel water. Concentrations of the abiotic parameters varied within the same ranges at all investigated depths, suggesting that interstitial water and channel water were very homogeneous, The exception was dissolved oxygen, where interstitial concentration was lower. However, the spatial distribution of interstitial dissolved oxygen, examined at a small scale (decimetre/centimetre level), did not follow a uniform pattern. These data contribute to a better understanding and documentation of sandy hyporheic zone characteristics.

Simple method for rating the decay stages of submerged woody debris

Previous investigations of interactions between aquatic invertebrates and decomposing wood substrates used wood decay classification systems based on external characteristics such as texture, shape, and color. These methods may be inaccurate for the assessment of wood decay because external appearance does not necessarily represent the physical state of decomposing wood. We tested an alternative method based on relative wood density adapted from terrestrial wood decomposition studies. We compared rating the physical condition of submerged twigs and branches by the loss of relative density to the traditional method based on external characteristics. Rating wood decay using loss of relative density showed distinct advantages compared to estimates by external characteristics. Measuring density delivered reproducible data independent of wood size or investigator bias. There was a correlation between decreases in relative wood density and increasing water content. In contrast, maximum water content was not correlated with the decay class rated by external characteristics. In addition, decay rating using external characteristics was influenced by the size of the woody debris. Rating wood decay using relative density is a simple and useful tool for characterizing woody debris in different stages of decay.

Insect emergence from a shallow southern West German lake, with special reference to the parasitic host-associated water mite larvae

Insect emergence was studied with floating box traps in the littoral of Lake Mindelsee from July 1st until September 30th, 1984. The material was collected every 48 h. Out of the total catch of 6897 specimens per m2, 75.1 % belonged to the Chironomidae, 4,9% to the Chaoboridae, 15,4% to the Ephemeroptera and 3,2% to the Trichoptera.Endochironomus sp., Lauterborniella agrayloides, Polypedilum pullum (Chironomidae) and Oocetis testacea (Trichoptera) are reported for the first time from Lake Mindelsee.The seasonal course of the total emergence showed two distinct peaks: one at the end of July, the other at the beginning of September.Diurnal emergence was studied on two occasions, in July and in August. Most of the insects emerged during dusk and dawn.Species composition and degree of water mite infection of the collected nematocerans were studied. Host range and specific attachment sites of the different water mite taxa could only be established on the genus or family-level, with the exception of the most common water mite species Hydrodroma despiciens. In addition to its main host Chaoborus flavicans, this mite species infested 16 chironomid species with Corynoneura sp., Cryptocladopelma viridula, Pseudochironomus prasinatus and Tanytarsus lactescens as new records. The larvae of Hydrodroma despiciens were attached almost exclusively to the thorax of the imagines. Chaoborus flavicans, and within the Chironomidae Procladius sp. of the subfamily Tanypodinae, showed the highest average mite load. Species of the subfamily Chironominae were also heavily infested (e.g. Microtendipes sp., infestation rate 76 % with a maximum mite load of 18). Within the representatives of the subfamily Orthocladiinae however, only low infestation rates occurred with maximum one larva per host.Finally, problems like the synchronization of the life-cycles of hosts and parasites and strategies of coexistence between the different water mite taxa parasitizing one host are discussed.

Epixylic biofilm and invertebrate colonization on submerged pine branches in a regulated lowland stream

Epixylic biofilm and invertebrate assemblages on pine branches (Pinus syl- vestris) experimentally submerged in October 2000 were investigated, after an initial colonization period of 3 months, by two-monthly sampling intervals for 13 months in a nutrient-rich sandy lowland stream subjected to flow disturbances caused by infre- quent impoundment openings. After 12 weeks of exposure an epixylic biofilm with 0.58 ± 0.25 µg/cm 2 chlorophyll-a (mean ± 1 SE) and 0.23 ± 0.04 µg/cm 2 ATP, as well as an abundant invertebrate community (14326 ± 2532 Ind/m 2 ; biomass: 974.6 ± 360.1 mg/m 2 ) became established on the branch surfaces. During the subsequent sam- pling dates invertebrate numbers decreased significantly during periods of high dis- charge and simultaneously chlorophyll-a values of epixylic biofilms increased, likely due to reduced feeding by invertebrate grazers. During periods with low discharge fluctuations and mainly low flow conditions, the epixylic biofilm, especially algal growth, was negatively correlated with invertebrate grazer and shredder numbers. After the initial growth period of 12 weeks, ATP values of the epixylic biofilm showed a strongly negative response to sand deposited on the wood surfaces. The present study displays the influence of seasonal discharge fluctuations and sand deposition on the wood surfaces on epixylic biofilms and invertebrate assembla- ges on experimentally submerged pine branches, but also indicate interactions between food sources (algae and fine particulate organic matter) and invertebrates (grazers and collector/gatherers).

The Effect of Low Flow and Stream Drying On the Distribution and Relative Abundance Of The Alien Amphipod, Echinogammarus Berilloni (Catta, 1878) In a Karstic Stream System (Westphalia, Germany)

[We found the alien amphipod, Echinogammarus berilloni (Catta, 1878) in a temporary karstic stream system (Westphalia, Germany). We investigated the effect of the seasonal low flow and desiccation on the distribution and the relative abundance of E. berilloni and on the native amphipods, Gammarus fossarum Koch, 1835 and G. pulex (Linnaeus, 1758). E. berilloni does not colonize the headwaters of the study area. Due to the seasonal low flow situation or even stream drying, this longitudinal limit of distribution can already occur in a further downstream section. After total drying the recolonization of E. berilloni in the temporary stream section mainly happens by drift from the permanent upstream sections, if a population has been established there. The relative abundance of E. berilloni and of the native amphipods, G. pulex and G. fossarum within the temporary stream sections is highly correlated with the temporary discharge regime. While in the permanent downstream sections E. berilloni successfully competes with the native gammarids and almost completely replaces them, Gammarus spp. dominate in the temporary reaches. Der Neozoe Echinogammarus berilloni (Catta, 1878) konnte in einem verkarsteten temporaren Fliesgewasser-System (Westfalen, Deutschland) nachgewiesen werden. Wir untersuchten den Einfluss von Austrocknung und Niedrigwasser auf die Verbreitung und relative Abundanz von E. berilloni und der heimischen Amphipoden, Gammarus fossarum Koch, 1835 und G. pulex (Linnaeus, 1758). E. berilloni besiedelt nicht die Oberlaufe des Untersuchungsgebietes. Diese langszonale Verbreitungsgrenze kann durch die saisonale Austrocknung oder Niedrigwassersituation bereits in einem unteren Gewasserabschnitt auftreten. Nach einer totalen Austrocknung erfolgt die Wiederbesiedlung der temporaren Gewasserabschnitte durch E. berilloni hauptsachlich per Drift aus den permanenten Abschnitten im Oberlauf der Karstgewasser, wenn dort eine Population vorhanden ist. Die relative Abundanz von E. berilloni und der heimischen Amphipoden, G. pulex und G. fossarum korreliert stark mit dem temporaren Abflussregime. Wahrend in den permanenten Gewasserabschnitten im Unterlauf der Karstgewasser E. berilloni die heimischen Gammariden fast vollstandig verdrangt, dominieren Gammarus spp. in den temporaren Gewasserabschnitten., We found the alien amphipod, Echinogammarus berilloni (Catta, 1878) in a temporary karstic stream system (Westphalia, Germany). We investigated the effect of the seasonal low flow and desiccation on the distribution and the relative abundance of E. berilloni and on the native amphipods, Gammarus fossarum Koch, 1835 and G. pulex (Linnaeus, 1758). E. berilloni does not colonize the headwaters of the study area. Due to the seasonal low flow situation or even stream drying, this longitudinal limit of distribution can already occur in a further downstream section. After total drying the recolonization of E. berilloni in the temporary stream section mainly happens by drift from the permanent upstream sections, if a population has been established there. The relative abundance of E. berilloni and of the native amphipods, G. pulex and G. fossarum within the temporary stream sections is highly correlated with the temporary discharge regime. While in the permanent downstream sections E. berilloni successfully competes with the native gammarids and almost completely replaces them, Gammarus spp. dominate in the temporary reaches. Der Neozoe Echinogammarus berilloni (Catta, 1878) konnte in einem verkarsteten temporaren Fliesgewasser-System (Westfalen, Deutschland) nachgewiesen werden. Wir untersuchten den Einfluss von Austrocknung und Niedrigwasser auf die Verbreitung und relative Abundanz von E. berilloni und der heimischen Amphipoden, Gammarus fossarum Koch, 1835 und G. pulex (Linnaeus, 1758). E. berilloni besiedelt nicht die Oberlaufe des Untersuchungsgebietes. Diese langszonale Verbreitungsgrenze kann durch die saisonale Austrocknung oder Niedrigwassersituation bereits in einem unteren Gewasserabschnitt auftreten. Nach einer totalen Austrocknung erfolgt die Wiederbesiedlung der temporaren Gewasserabschnitte durch E. berilloni hauptsachlich per Drift aus den permanenten Abschnitten im Oberlauf der Karstgewasser, wenn dort eine Population vorhanden ist. Die relative Abundanz von E. berilloni und der heimischen Amphipoden, G. pulex und G. fossarum korreliert stark mit dem temporaren Abflussregime. Wahrend in den permanenten Gewasserabschnitten im Unterlauf der Karstgewasser E. berilloni die heimischen Gammariden fast vollstandig verdrangt, dominieren Gammarus spp. in den temporaren Gewasserabschnitten.]

Secondary production of invertebrates in a Central European mountain stream (Steina, Black Forest, Germany)

We estimated macroinvertebrate production in the Central European mountain stream Steina over 3 years from November 1985 to October 1988 applying the increment-summation method and additional P/B ratios from literature. Total production differed little between the three study years, amounting to 19.0 (1986), 19.7 (1987) and 20.8 g m -2 y -1 (1988). Ephemeroptera, Trichoptera and Diptera contributed most to total invertebrate production. Whereas the production of Tricladida, Oligochaeta, Acari, Crustacea, and Coleoptera remained more or less stable over the three study years, it showed in part distinct trends or between-year variation in the three most dominant orders. Mayfly production increased from 4.7 to 7.2 g m -2 y -1 and stonefly production from 1.8 to 2.3 g m -2 y -1 . Caddisfly production showed a decreasing tendency from 1986 (6.8 gm -2 y -1 ) to 1988 (4.0 g m -2 y -1 ). Marked differences, increasing or decreasing values, occurred at some species level. Secondary production of all primary consumers in the Steina was 16.7 (1986, 1987) and 17.9 (1988) g m -2 y -1 over the three-year time span. Production of secondary consumers (predators) amounted to 2.3-3.0 g m -2 y -1 of total production, and was 2.7 g m -2 y -1 on average. Analysis of the portions of functional groups revealed that suspension feeders and predators accounted for only 12.8-17.8 % of total production, whereas the relative contribution of scrapers was about 24 % in 1986 and 1987, and even reached 38 % in 1988. Production of shredders and deposit feeders reached the same order of magnitude as scrapers, particularly in 1986. However, there was a decreasing tendency in production of shredders and deposit feeders and an increasing tendency in production of scrapers and suspension feeders towards the 3rd year.