ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Leaf litter processing and exoenzyme production on leaves in streams of different pH (1995)
    Springer
    Oecologia 102 (1995), S. 460-466 
    Details
    ISSN: 1432-1939
    Keywords: Detrital processing ; Exoenzymes ; ATP ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We examined microbial colonization, exoenzyme activity, and processing of leaves of yellow poplar (Liriodendron tulipifera), red maple (Acer rubrum), and white oak (Quercus alba) in three streams on the Allegheny Plateau of West Virginia, United States. Leaf packs were placed in streams that varied in their underlying bedrock geology, and therefore in their sensitivity to the high level of acidic precipitation that occurs in this region. The mean pH of the streams was 4.3 in the South Fork of Red Run (SFR), 6.2 in Wilson Hollow Run (WHR), and 7.7 in the North Fork of Hickman Slide Run (HSR). Through time, the patterns of microbial biomass and exoenzyme activity were generally similar among leaf species, but the magnitude of microbial biomass and exoenzyme activity differed among leaf species. Pectinase activity was greatest in HSR, the most alkaline stream, whereas the activity of exocellulase and xylanase was greatest in WHR and SFR, the intermediate and acidic streams. This variation in the activity of different exoenzymes was consistent with published pH optima for these exoenzymes. Variation in processing rates, both among leaf species and among streams, seems to be related to the level of microbial exoenzyme activity on the leaf detritus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00341358
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Response of soil and leaf litter microarthropods to forest application of diflubenzuron (1997)
    Springer
    Ecotoxicology 6 (1997), S. 87-99 
    Details
    ISSN: 1573-3017
    Keywords: Diflubenzuron ; forest application ; soil arthropods
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The objective of this study was to assess the effects of forest application of diflubenzuron (Dimilin®), a gypsy moth suppressant, on nontarget invertebrates in litter and soil on the forest floor. Four experimental watersheds (two treatment and two reference) in the Fernow Experimental Forest, West Virginia, were sampled for two years before and one year after application of diflubenzuron (70 g ha−1, AI). Soil and leaf litter arthropods were monitored before and after application using soil cores and litter bag colonization samplers. Frequency analysis, BACIP, and ANOVA were used to analyse the data for diflubenzuron treatment effects. During the 36 month study, soil core samples were dominated by mites (49%) and springtails (28%). A total of 19 taxonomic groups were suitable for statistical analysis. We detected no significant treatment effects based on total organism counts or counts by trophic categories (p 〈 0.05). There were no significant treatment effects for populations of major taxonomic groups, except for Araneae (spiders). Analysis of leaf litter bags also showed no significant differences in total numbers of invertebrates or in trophic categories between treated and reference watersheds during the 12 month post-treatment study. Density of one species of springtail (Sminthurus purpurescens) and springtails as a group were significantly lower in treated watersheds. High variation was associated with both soil core and leaf bag samples; because of this variation, a significance level of 0.05 should be considered very conservative. Long-term trends in soil biota were evident, demonstrating the need for well-established pre-treatment baseline data for pesticide impacts on soil organisms
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018658223388
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Differential growth of crayfish Procambarus alleni in relation to hydrological conditions in marl prairie wetlands of Everglades National Park, USA (2000)
    Springer
    Aquatic ecology 34 (2000), S. 389-395 
    Details
    ISSN: 1573-5125
    Keywords: crayfish ; Procambarus alleni ; growth ; Florida Everglades ; hydroperiod
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Environmental conditions influence crustacean growth by affecting molt intervals and incremental increases in length and weight. In the seasonally-flooded marl prairie wetlands of eastern Everglades National Park, U.S.A., hydropattern exerts considerable influence on aquatic primary productivity, and so may influence the availability of food resources for higher trophic levels. The seasonal hydroperiod has been drastically altered by anthropogenic factors, but the impacts on the aquatic community are not well known. We studied whether differences in growth of crayfish Procambarus alleni could be detected in habitats with different hydroperiods. We first described growth patterns based on incremental increases in length and weight of crayfish on a high protein diet in the laboratory. Regression analyses indicated that growth patterns in males and females were similar. Although the intermolt period increased with age, the proportional increases in length and weight were similar through successive molts. The relationship between length and weight of crayfish was best described by a power equation for allometric growth. We then compared growth curves for crayfish subpopulations from different areas of the marl prairie. In habitats with the longest hydroperiods, crayfish weight-at-size was not significantly different from that in laboratory crayfish on the high protein diet. However, weight gain per unit increase in length in short hydroperiod sites was significantly less than in long hydroperiod sites or in the laboratory. These results indicate that crayfish productivity may be associated with hydroperiod in these stressed wetlands, and this may contribute to observed source-sink population regulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1011472828639
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Between-year variation of periphyton community structure in two Appalachian headwater streams (1995)
    Springer
    Hydrobiologia 302 (1995), S. 1-9 
    Details
    ISSN: 1573-5117
    Keywords: algal densities ; periphyton ; headwater streams
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We used unglazed quarry tiles to survey periphyton community structure in two small Appalachian mountain streams from January through April in 1990, 1991, and 1992. Mean periphyton cell densities were greatest in 1990 (maximum of 1.3 × 108 cells cm−2), the year with the fewest periods of high discharge; cell densities were lowest in 1991 (maximum of 5.9 × 105 cells cm−2), the year characterized by the most periods of high discharge, and intermediate in 1992 (maximum of 2.1 × 106 cells cm−2). Mean cell densities of the dominant alga, the cyanophyte Chamaesiphon sp., followed this pattern, but some taxa of diatoms did not.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00006394
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Detrital processing in streams exposed to acidic precipitation in the Central Appalachian Mountains (1996)
    Springer
    Hydrobiologia 339 (1996), S. 101-110 
    Details
    ISSN: 1573-5117
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Continuing high rates of acidic deposition in the eastern United States may lead to long-term effects on stream communities, because sensitive catchments are continuing to lose anions and cations. We conducted a two-year study of the effects of pH and associated water chemistry variables on detrital processing in three streams with different bedrock geology in the Monongahela National Forest, West Virginia. We compared leaf pack processing rates and macroinvertebrate colonization and microbial biomass (ATP concentration) on the packs in the three streams. Breakdown rates of red maple and white oak leaf packs were significantly lower in the most acidic stream. The acidic stream also had significantly lower microbial and shredder biomass than two more circumneutral streams. Shredder composition differed among streams; large-particle detritivores dominated the shredder assemblages of the two circumneutral streams, and smaller shredders dominated in the acidic stream. Within streams, processing rates for three leaf species were not significantly different between the two years of the study even though invertebrate and microbial communities were different in the two years. Thus, macroinvertebrate and microbial communities differed both among streams that differed in their capacity to buffer the effects of acidic precipitation and among years in the same stream; these differences in biotic communities were not large enough to affect rates of leaf processing between the two years of the study, but they did significantly affect processing rates between acidic and circumneutral streams.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00008918
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Effects of experimental flow regulation on invertebrate drift and stranding in the Flathead and Kootenai Rivers, Montana, USA (1986)
    Springer
    Hydrobiologia 134 (1986), S. 171-182 
    Details
    ISSN: 1573-5117
    Keywords: regulated rivers ; flow fluctuations ; invertebrate drift ; stranding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Studies were conducted to determine the effects of experimental manipulations of discharge on invertebrate drift in two regulated rivers in northwestern Montana, USA. During these studies the discharge regime in the Flathead River was characterized by frequent flow fluctuations, while in the Kootenai River high discharge was maintained for much longer periods before flow was reduced to minimum discharge. The magnitude of the response of invertebrates to disturbance was different in the two rivers, in part because of the different frequencies of flow changes. Midstream invertebrate drift increased an order of magnitude during increasing discharges in the Flathead River but was not substantially increased during decreasing discharges. When the prior discharge regime had been sustained at high levels in the Kootenai River, invertebrate drift densities as high as 300 000/100 m3 were measured along the shoreline following reductions in discharge, both immediately after flow began to decrease and after dark on the same day. There was also more recolonization of shoreline areas and more stranding of insects following dewatering of nearshore regions when there had been sustained high discharge levels prior to the flow reduction. More insect stranding occurred during a faster rate of decrease in discharge (50 000 to 100 000 organisms m−2).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00006739
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Effects of exported seston on aquatic insect faunal similarity and species richness in lake outlet streams in Montana, USA (1986)
    Springer
    Hydrobiologia 137 (1986), S. 65-77 
    Details
    ISSN: 1573-5117
    Keywords: lake outlets ; benthic insects ; detrended correspondence analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The quantity of seston exported from a lake affected the qualitative composition and species richness of aquatic insects in 13 lake outlet streams in northwestern Montana. Mean values for chlorophyll and particulate organic carbon in lake effluent waters ranged from 0.5 to 2.7 and 80 to 601 mg m-3, respectively. Correlations between a detrended correspondence analysis of faunal similarities in outlet streams and measures of organic export from the lake indicated that distributional patterns were primarily dependent upon the general trophic status of the lakes. A comparison of faunal assemblages at stream stations located at the outlet and 100 m downstream demonstrated that species composition at the two stations was more similar in productive systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00004174
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Fungal biomass and leaf litter processing in streams of different water chemistry (1994)
    Springer
    Hydrobiologia 294 (1994), S. 51-61 
    Details
    ISSN: 1573-5117
    Keywords: leaf litter decomposition ; streams ; water chemistry ; pH ; ergosterol ; microbial communities ; aquatic hyphomycetes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Leaf litter processing rates and fungal biomass on leaf detritus were compared in four streams of different water chemistry. The streams drained catchments underlain by different bedrock types and varied in mean pH from 4.3 to 7.5 and in mean alkalinity from 0.0 to 35.8 mg CaCO3 l−1. Processing rates were fastest in WS3 and WS4, which had a pH of 6.0; slowest in SFR, which had a pH of 4.3; and intermediate in HSR which had a pH of 7.5. Fungal biomass as measured by the fungal sterol, ergosterol, was similar in WS3, WS4, and HSR but was much lower in SFR. These results suggest that reduced processing rates in SFR were associated in part with reduced fungal biomass on the leaves, whereas reduced processing rates in HSR were not related to differences in fungal biomass on the leaves.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00017625
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Secondary production of Rhyacophila minora, Ameletus sp., and Isonychia bicolor from streams of low and circumneutral pH in the Appalachian Mountains of West Virginia (1994)
    Springer
    Hydrobiologia 273 (1994), S. 163-169 
    Details
    ISSN: 1573-5117
    Keywords: secondary production ; streams ; aquatic insects ; Rhyacophila minora ; Trichoptera ; Ameletus sp. ; Isonychia bicolor ; Ephemeroptera ; acidification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We estimated the secondary production of Rhyacophila minora, Ameletus sp., and Isonychia bicolor in three acidic streams and one circumneutral stream in Randolph County, West Virginia. Quantitative benthic samples were collected monthly from these second-order streams from November 1990 to October 1991. Mean pH values in the acidic streams were 4.5, 4.8, and 4.8, and mean pH in the circumneutral stream was 6.7. Production estimates for Rhyacophia minora in the acidic streams were 49.6, 19.2, and 15.8 mg m−2 y−1. Production of R. minora in the circumneutral stream was 1.0 mg m−2 y−1. Ameletus sp. production estimates for the acidic streams were 144.8, 176.8, and 208.3 mg m−2 y−1. Ameletus sp. production in the circumneutral stream was 7.4 mg m−2 y−1. Secondary production of I. bicolor in the circumneutral stream was 116.6 mg m−2 y−1. No Isonychia were collected from the acidic streams. The higher production of R. minora and Ameletus sp. in the acidic streams may be associated with differences in macroinvertebrate community structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00005639
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Organic carbon dynamics in two regulated rivers in northwestern Montana, USA (1991)
    Springer
    Hydrobiologia 218 (1991), S. 193-203 
    Details
    ISSN: 1573-5117
    Keywords: dissolved organic carbon ; particulate organic carbon ; organic matter transport ; regulated rivers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We studied the transport of particulate organic carbon (POC) and dissolved organic carbon (DOC) in two regulated rivers during minimum and increasing discharges. Mean annual concentrations of total POC, measured monthly during conditions of minimum discharge from the dams, were twice as high at a station below a dam with a selective withdrawal system on the Kootenai River (KR, 0.15 mg 1−1), as at station below a dam with hypolimnetic water releases on the Flathead River (FR, 0.07 mg 1−1). Annual mean concentrations of DOC were similar below both dams (1.62 mg 1−1 FR; 1.71 KR). The percentage of POC in four size fractions differed in regulated and unregulated reaches of each river system; the smallest size fraction (0.45–10 smm) constituted a larger percentage of the total POC at the stations below the dams (50–93%), because POC in large size classes had settled out in the reservoir. The three largest size fractions (10–1000 µm) comprised a larger percentage of the total POC when samples were taken during conditions of full discharge from the dam. We measured large increases in all size classes of POC in samples collected during increasing discharges in a regulated reach, reflecting the component of sloughed periphyton and resuspended organic matter that were added during periods of hydropower generation at the dam. Seston (355 µm to 1 cm) collected in nets increased dramatically during increasing flows; concentrations of particulate organic matter (POM) in samples collected two and three hours after water levels began to rise were 572 and 1440 times higher than those collected during minimum discharge at the dam.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00038835
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...