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1.
Ana F. Filipe Miguel B. Araújo Ignacio Doadrio Paul L. Angermeier Maria J. Collares-Pereira 《Journal of Biogeography》2009,36(11):2096-2110
Aim The question of how much of the shared geographical distribution of biota is due to environmental vs. historical constraints remains unanswered. The aim of this paper is to disentangle the contribution of historical vs. contemporary factors to the distribution of freshwater fish species. In addition, it illustrates how quantifying the contribution of each type of factor improves the classification of biogeographical provinces. Location Iberian Peninsula, south‐western Europe (c. 581,000 km2). Methods We used the most comprehensive data on native fish distributions for the Iberian Peninsula, compiled from Portuguese and Spanish sources on a 20‐km grid‐cell resolution. Overall, 58 species were analysed after being categorized into three groups according to their ability to disperse through saltwater: (1) species strictly intolerant of saltwater (primary species); (2) species partially tolerant of saltwater, making limited incursions into saltwaters (secondary species); and (3) saltwater‐tolerant species that migrate back and forth from sea to freshwaters or have invaded freshwaters recently (peripheral species). Distance‐based multivariate analyses were used to test the role of historical (basin formation) vs. contemporary environmental (climate) conditions in explaining current patterns of native fish assemblage composition. Cluster analyses were performed to explore species co‐occurrence patterns and redefine biogeographical provinces based on the distributions of fishes. Results River basin boundaries were better at segregating species composition for all species groups than contemporary climate variables. This historical signal was especially evident for primary and secondary freshwater fishes. Eleven biogeographical provinces were delineated. Basins flowing to the Atlantic Ocean north of the Tagus Basin and those flowing to the Mediterranean Sea north of the Mijares Basin were the most dissimilar group. Primary and secondary freshwater species had higher province fidelity than peripheral species. Main conclusions The results support the hypothesis that historical factors exert greater constraints on native freshwater fish assemblages in the Iberian Peninsula than do current environmental factors. After examining patterns of assemblage variation across space, as evidenced by the biogeographical provinces, we discuss the likely dispersal and speciation events that underlie these patterns. 相似文献
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3.
FRAUKE M. MUENZEL MATTHIAS SANETRA WALTER SALZBURGER AXEL MEYER 《Molecular ecology resources》2007,7(6):1048-1050
Eleven microsatellites were isolated from the vairone Leuciscus souffia (Risso 1826), an endangered fish that inhabits river systems in and around the Alps in Europe. The level of genetic diversity was assessed in 29 individuals of the subspecies L. s. souffia, and their variability was further estimated in seven individuals of a different subspecies, L. s. muticellus. Eight of these microsatellite loci were also applied to seven closely related cyprinid species. Availability of the reported microsatellite loci will facilitate the investigation of population genetic structure of these species with applications for the development of conservation strategies and phylogeographical approaches. 相似文献
4.
Gene flow between populations of two invertebrates in springs 总被引:2,自引:0,他引:2
1. Using allozymes, we analysed genetic structure of the freshwater gastropod Bythinella dunkeri and the freshwater flatworm Crenobia alpina. The two species are habitat specialists, living almost exclusively in springs. The sampled area in Hesse (Germany) covers a spatial scale of 20 km and includes two river drainages. From the biology of the two species we expected little dispersal along rivers. However, the possibility exists that groundwater provide suitable pathways for dispersal. 2. In B. dunkeri heterozygosity decreased from west to east. For some alleles we found clines in this geographic direction. These clines generated a positive correlation between geographic distance and genetic differentiation. Furthermore patterns of genetic variation within populations suggested that populations may have been faced with bottlenecks and founder effects. If populations are not in population genetic equilibrium, such founder effects would also explain the rather high amount of genetic differentiation between populations (10%). 3. For C. alpina the mean number of alleles decreased with increasing isolation of populations. Genetic differentiation between populations contributed 19% to the total genetic variation. Genetic differentiation was not correlated to geographic distance, but compared with B. dunkeri variability of pairwise differentiation between pairs of populations was higher in C. alpina. 4. Overall B. dunkeri appears to be a fairly good disperser, which may use groundwater as dispersal pathway. Furthermore populations seem to be not in equilibrium. In contrast C. alpina forms rather isolated populations with little dispersal between springs and groundwater seems to play no important role for dispersal. 相似文献
5.
Arash Masbough Kevin Frankowski Ken J. Hall Sheldon J.B. Duff 《Ecological Engineering》2005,25(5):552
Percolation of rainfall through woodwaste piles leaches natural chemicals from the wood residuals that can have adverse impacts on the environment. A study was conducted on a woodwaste storage site, adjacent to the Lower Fraser River, near Mission, BC, Canada. The objective of this research was to evaluate the effectiveness of constructed wetland for treatment of this woodwaste leachate. The leachate was characterized by high oxygen demand, tannin and lignin, and volatile fatty acids (VFAs), but low pH and nutrients. Diluted leachate passed through six pilot-scale wetland cells, four planted with cattail (Typha latifolia) and two unplanted controls, with a hydraulic retention time of 7 days and an average depth of 40 cm. Nutrient addition and pH adjustments were made to improve contaminant removal. Reductions in contaminants were consistently achieved, with average removals for BOD, COD, VFAs and tannin and lignin of 60, 50, 69 and 42%, respectively. Climatic conditions had an impact on the performance of the constructed wetland. Further operation of the system will help to elucidate the seasonal fluctuations. Aging of the constructed wetland system increased the treatment performance. 相似文献
6.
The Orlando Easterly Wetland (OEW), located near Christmas, Florida, USA, is among the longer-lived treatment wetlands in the United States. It was established in the late 1980s to reduce nitrogen and phosphorus concentrations from tertiary treated wastewater bound for the St. Johns River. A goal of 0.07 mg/l total phosphorus concentration has been set by the regulating agency (St. Johns River Water Management District). In order to understand and define the operating conditions for which this target could be met, a systematic study of historic phosphorus uptake was performed using a traditional first-order model. Phosphorus uptake performance is shown to correlate well with hydraulic performance for two parallel upstream cells. The first-order model is enhanced with predictive capabilities that acknowledge the correlation between the phosphorus uptake rate constant and the hydraulic loading rate observed in the system. Inherent limitations with the first-order modeling approach are addressed and uncertainty in model performance is used to bound predictions. 相似文献
7.
Systems ecological accounting for wastewater treatment engineering: Method,indicator and application
Wastewater treatment facility is vital for sustainable urban development. In the course of removing contaminants and discharging ready-for-reuse water, wastewater treatment consumes resources and triggers environmental emission during its lifetime. A comprehensive framework to analyze the embodied ecological elements as natural resources and environmental emissions of wastewater treatment is presented in this work. The systems method as a combination of process and input–output analyses is applied and a set of indicators are accordingly devised. Two representative ecological elements, i.e., greenhouse gases emissions and solar emergy of alternative wastewater treatment systems, i.e., a traditional activated sludge wastewater treatment plant and a constructed wetland have been taken into consideration. For each ecological element, five indicators have been calculated and compared to assess the impact on climate change and resources utilizing style of the case systems. The framework raised in this paper is fully supportive for optimal decision-making among different wastewater treatment technologies, and could be transplanted to be applied to systems ecological accounting for other production systems. 相似文献
8.
Christophe Piscart Alain Manach Gordon H. Copp Pierre Marmonier 《Journal of Biogeography》2007,34(3):524-533
Aim To assess temporal changes in gammarid distribution in Brittany and microhabitat-use overlap between the endangered endemic Gammarus duebeni celticus Stock & Pinkster, 1970 , the expanding natives G. pulex (Linnaeus, 1758) and Echinogammarus berilloni (Catta, 1878), and the introduced G. tigrinus Sexton, 1939.
Location Brittany and adjacent regions in western France.
Methods The spatial and temporal patterns in distribution of gammarids at the scale of Brittany were studied using 351 sites. Longitudinal distributions (from the source to the estuary of the river) and microhabitat-use (substratum type and water velocity) were also considered in selected rivers.
Results At the regional scale, all species occurred together less often than expected statistically, with significant deviations from expected for G. pulex vs. both G. duebeni celticus and G. tigrinus , and for E. berilloni vs. both G. duebeni celticus and G. tigrinus . However, at the microhabitat scale, E. berilloni occurred significantly more often than expected with the endemic G. duebeni celticus , and this appears to be due to similar substratum and water velocity preferences, although at both the regional and microhabitat scales E. berilloni prefers wider streams than G. duebeni celticus . This study reveals a decline in the endangered G. duebeni celticus since 1970.
Main conclusions The longitudinal and local distributions of G. duebeni celticus , and the higher-than-expected co-occurrence of the species with G. pulex , suggest that the decline of the endemic species may be due to changes in the environment and/or interference from native G. pulex , which is expanding its range in Brittany. The results are discussed as regards to the consequences for regional biodiversity. 相似文献
Location Brittany and adjacent regions in western France.
Methods The spatial and temporal patterns in distribution of gammarids at the scale of Brittany were studied using 351 sites. Longitudinal distributions (from the source to the estuary of the river) and microhabitat-use (substratum type and water velocity) were also considered in selected rivers.
Results At the regional scale, all species occurred together less often than expected statistically, with significant deviations from expected for G. pulex vs. both G. duebeni celticus and G. tigrinus , and for E. berilloni vs. both G. duebeni celticus and G. tigrinus . However, at the microhabitat scale, E. berilloni occurred significantly more often than expected with the endemic G. duebeni celticus , and this appears to be due to similar substratum and water velocity preferences, although at both the regional and microhabitat scales E. berilloni prefers wider streams than G. duebeni celticus . This study reveals a decline in the endangered G. duebeni celticus since 1970.
Main conclusions The longitudinal and local distributions of G. duebeni celticus , and the higher-than-expected co-occurrence of the species with G. pulex , suggest that the decline of the endemic species may be due to changes in the environment and/or interference from native G. pulex , which is expanding its range in Brittany. The results are discussed as regards to the consequences for regional biodiversity. 相似文献
9.
Carlos Eduardo Falavigna da Rocha Maria Helena Gonzaga de Carvalho Bjornber 《Hydrobiologia》1987,153(2):97-107
Cyclopid copepods collected mainly in aquatic microcosms and semiterrestrial habitats in the Juréia Ecological Reserve are studied. Hesperocyclops herbsti and Bryocyclops campaneri are described as new species and their taxonomical relationships discussed. Females of Muscocyclops operculatus (Chappuis) are redescribed and the males described for the first time. An emended diagnosis for Muscocyclops is proposed. 相似文献
10.
Possible causes of high species diversity in tropical Australian freshwater macrobenthic communities 总被引:2,自引:2,他引:0
P.M. Outridge 《Hydrobiologia》1987,150(2):95-107
A total of 133 benthic macroinvertebrate species was recorded in four permanent freshwater lagoons (billabongs) and a stream riffle in the Magela Creek catchment, Northern Territory, Australia. 101 species were lentic in occurrence. Each billabong supported at least as many species as larger tropical and Australian temperate lakes, and was an exception to the species-poor status of Australian lentic macrobenthic communities. > 98% of the total benthic biomass was contributed by a mussel species; the remaining species' combined standing crop was an order of magnitude lower than in other lentic systems, further highlighting the diversity of the Magela benthos. Rarefaction (removal of organisms) and predictable environmental heterogeneity, both related to monsoonal variations in flow and water quality, were probably important determinants of the high diversity of these communities. 相似文献