Felix Baerlocher

Felix Baerlocher
Mount Allison University · Department of Biology

dipl. sc. nat. ETH, Ph.D. (Waterloo)

About

467
Publications
95,529
Reads
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12,211
Citations
Additional affiliations
July 1983 - present
Mount Allison University
Position
  • Professor (Full)
July 1976 - July 1983
University of Basel
Position
  • Lecturer
June 1975 - July 1976
University of Waterloo
Position
  • PostDoc Position

Publications

Publications (467)
Article
Research on freshwater fungi has concentrated on their role in plant litter decomposition in streams. Higher fungi dominate over bacteria in terms of biomass, production and enzymatic substrate degradation. Microscopy-based studies suggest the prevalence of aquatic hyphomycetes, characterized by tetraradiate or sigmoid spores. Molecular studies hav...
Article
The growth rate hypothesis states that in many organisms or tissues, the specific growth rate μ correlates with RNA concentrations. Since RNA often accounts for much of the phosphorus content of cells, μ may also correlate positively with P concentrations and negatively with C:P and N:P ratios. We tested this hypothesis with broth cultures of five...
Chapter
Food chains and food webs summarize feeding relation- ships between organisms in an ecosystem. The resulting patterns greatly affect biomagnificiation and bioaccumu- lation. The complexity of food webs can be expressed by connectance C (ratio of observed number of links vs. total number of theoretically possible links) and the interac- tive strengt...
Article
Full-text available
Microbial decomposers, especially a fungal group called aquatic hyphomycetes, play a critical role in processing plant litter in freshwaters by increasing its palatability to invertebrate shredders. Traditionally, communities of aquatic hyphomycetes have been assessed through the identification of spores, which misses non-sporulating taxa. Among ne...
Chapter
Headwater streams, especially those flowing through forested landscapes, are mainly detritus-based systems. The interactions between leaf litter, microbial decomposers and invertebrate detritivores set the course for the vital carbon flow in these ecosystems. Among the microbial decomposers, fungi, particularly aquatic hyphomycetes (AQHs) are the p...
Article
The length and number of streams experiencing intermittency is expected to increase in response to human population growth, associated water use, and climate change. In these streams, habitat contraction may occur at distinct rates giving rise to drying periods of distinct duration. To date, the impact of drought installation rate and duration have...
Chapter
Human activities are altering ion composition and concentrations in streams around the globe. This has implications for aquatic biota and for key ecosystem functions such as leaf litter decomposition. In this chapter we present an overview of the causes of stream salinization and its impacts on litter decomposition through changes in the quality an...
Article
Freshwater salinization is a world-wide phenomenon threatening stream communities and ecosystem functioning. In these systems, litter decomposition is a main ecosystem-level process where fungi (aquatic hyphomycetes) play a central role linking basal resource and higher levels of food-web. The current study evaluated the impact of aquatic hyphomyce...
Chapter
Litter decomposition in freshwaters has been studied for over 60 years with several questions being addressed repeatedly. However, due to differences in experimental approach and design, environmental conditions, sample size, and magnitude of the effect, results vary across studies making general conclusions difficult, especially by non-specialists...
Chapter
Scientific investigations typically begin with the collection of data. Summarizing and representing the collected data is labelled “descriptive statistics”; conclusions, predictions, or diagnoses based on these data fall under the domain of “inferential statistics.” Inferences are never completely certain and are therefore expressed as probabilitie...
Chapter
A very substantial proportion of fungal production, often in excess of 50%, is invested in propagules that are released from decomposing leaves in streams. Asexually produced spores (mitospores, conidia) dominate. On leaves freshly recovered from a stream, only a few conidia can be observed. However, if such leaves are incubated for 1 – 2 days unde...
Chapter
Leaf litter is a dominant component of coarse particulate organic matter in streams. In view of its central place in ecosystem functioning, estimates of its mass loss have been proposed to evaluate functional stream integrity. This chapter describes a standardized method to estimate mass loss by using litter bags, including statistical analysis of...
Chapter
Tannins are polymeric compounds with sufficient phenolic groups to complex with proteins and other macromolecules. Total concentrations of tannins in leaf litter are often negatively correlated with feeding preferences and digestion efficiencies of consumers, and with microbial decomposition rates. This chapter presents a method to estimate total t...
Chapter
Assessments of fungal communities based on spores released from decaying leaves miss non-sporulating mycelia. Molecular approaches circumvent this problem. This chapter presents one molecular method, denaturing gradient gel electrophoresis (DGGE), which is based on the PCR amplification of a gene present in all community members and subsequent sepa...
Chapter
Nitrogen tends to be scarce in decaying leaves, and its accessibility to invertebrates is further lowered by plant polyphenolics. The ability to extract and digest nitrogen from leaves is therefore crucial for stream detritivores. This chapter describes two simple methods to estimate proteolytic activity. Tipulid or other invertebrate guts are cut...
Chapter
The identification of aquatic hyphomycetes associated with decomposing leaves in streams has been traditionally based on inducing sporulation, but this approach misses non-sporulating mycelia. Molecular methods based on analyzing nucleic acid sequences circumvent this problem. They rely on the amplification of DNA with taxon-specific primers and su...
Chapter
Consumers often prefer specific food items while ignoring others. Measuring these preferences is straightforward in food-choice experiments designed for consumers capable of feeding on plant litter (shredders): specimens are placed in a container and are given a choice among different types of litter. The amount of each food item consumed is estima...
Chapter
Phenolics are a heterogeneous group of natural substances characterized by an aromatic ring with one or more hydroxyl groups. Among the compounds with several phenolic hydroxyl substituents, tannins are of particular interest because of various ecological roles, especially as defense compounds against herbivores and pathogens, but also in communica...
Chapter
There is great concern about the ongoing decline of biodiversity. An important question is how this loss will affect ecosystem functioning. To approach this issue, we need to define biodiversity and choose appropriate methods to measure it. At its most basic level, diversity of a community may be expressed by the number of distinct species it conta...
Chapter
The decomposition of autumn-shed leaves in streams has traditionally been subdivided into three more or less distinct phases: leaching, microbial colonization and invertebrate feeding. Leaching is defined as the abiotic removal of soluble substances, among them phenolics, carbohydrates and amino acids. The rate of leaching and the composition of le...
Book
This edited volume is an extensive collection of methods for investigating plant litter dynamics in ecosystems. Particular emphasis is placed on litter decomposition in streams and rivers. The presented methods range from analyses of chemical and physical litter properties to the taxonomic and functional characterization of microbial decomposers, b...
Article
Anthropogenic salinization of freshwater is a global problem with largely unknown consequences for stream functions. We compared the effects of salt addition (6 g l21 NaCl) in microcosms on leaf mass loss and microbial parameters in single- and multispecies assemblages of fungal strains (Heliscus lugdunensis, HELU; Tetracladium marchalianum, TEMA;...
Article
Global patterns of biodiversity have emerged for soil microorganisms, plants and animals, and the extraordinary significance of microbial functions in ecosystems is also well established. Virtually unknown, however, are large-scale patterns of microbial diversity in freshwaters, although these aquatic ecosystems are hotspots of biodiversity and bio...
Article
Protein fingerprinting using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-­TOF MS) is a rapid, reliable, and economical method to characterize isolates of terrestrial fungi and other microorganisms. The objective of our study was to evaluate the suitability of MALDI-TOF MS for the identification of aquatic hyp...
Article
Human-induced salinization of freshwaters constitutes a growing global problem, whose consequences on streams functioning are largely unknown. Climate change projections predict enhanced evaporation, as well as an increase in extreme events and in variability of precipitation. This will result in more frequent, extended and severe drought periods t...
Article
Full-text available
Abstract The taxonomy of the aquatic hyphomycete genus Articulospora (Ascomycota, Pezizomycotima, Leotiales, Helotiaceae) is based on the morphology of the generative phase of its lifecycle. The type species is Articulospora tetracladia, which is distributed worldwide. Its most frequent populations in nature have dimorphic conidia, differing by the...
Article
The addition of 4-ethyl-3-thiosemicarbazide to benzaldehyde and boronic acid containing derivatives afforded the corresponding thiosemicarbazones (1-3) or benzodiazaborines (4-6) depending on the position of the boronic acid within the ring. All compounds have been characterized fully including an X-ray diffraction study of the methoxy-containing b...
Article
Full-text available
Gravity and magnetism are implemented to change the morphology of zinc oxide nanorod sensors during synthesis. The effects of gravity and magnetism can translate into future application of these nanorods through cost-effective, environmentally friendly, and easy-to-use biosensor technology with the quickest available sensing. The sensors can pave t...
Chapter
Small streams depend on inputs of allochthonous organic matter such as leaf litter and wood to fuel their ecosystems. Decomposition of these substrates is driven mainly by fungi, while the role of bacteria on coarse particulate organic matter is minor. Thus, fungi, especially aquatic hyphomycetes, are important components of stream ecosystems and k...
Article
Salinization is of major global concern due to its effect on stream biota, and ecosystem functions and services. In small streams, litter decomposition is a key ecosystem-level process driven by decomposers, mainly fungi (aquatic hyphomycetes), which link litter and invertebrates. Here we assessed the effects of an environmentally relevant range of...
Article
Full-text available
One of the fundamental patterns in macroecology is the increase in the number of observed taxa with size of sampled area. For microbes, the shape of this relationship remains less clear. The current study assessed the diversity of aquatic fungi, by the traditional approach based on conidial morphology (captures reproducing aquatic hyphomycetes) and...
Data
ITS PCR and RT-PCR products for each treatment. Products were generated from DNA and RNA pools from leaf disks that were immersed at Boss Brook. M) DNA ladder BenchTop 100 bp (Promega), 1) DNA 0.6 cm2, 2) DNA 1.1 cm2, 3) DNA 2.3 cm2, 4) DNA 4.5 cm2, 5) DNA 9.0 cm2, 6) DNA 13.6 cm2, 7) DNA negative control, 8) RNA 0.6 cm2, 9) RNA 1.1 cm2, 10) RNA 2....
Data
Z values (+ SE) obtained in studies reporting taxa-area relationships for aquatic hyphomycetes (morphospecies). Narrator Brook [26], Ibach [27], Oliveira Stream (current study) and Boss Brook (current study). The dashed line represents the z value calculated by using the data from all studies and the power function (Eq 3). (TIF)
Data
List of OTUs with hits for fungi (total for DNA and active for RNA data). The list includes closest NCBI database match and respective % identity and accession number and maximum % contribution of each OTU, based on the number of reads, on leaf disks submerged in Oliveira Stream and Boss Brook. *OTUs with close hits with aquatic hyphomycete sequenc...
Data
Model parameters of the relationship between fungal taxa diversity and leaf area (Fig 4a and 4c) in TAR curves. The exponential (EC) (Eq 4) and the logistic (LC) models (Eq 5) [4] were used. (DOCX)
Data
Model parameters of the relationship between fungal taxa diversity and leaf area (Fig 4b and 4d) in TAC curves. The exponential (EC) (Eq 4) and the logistic (LC) models (Eq 5) [4] were used. (DOCX)
Data
N° of reads on alder leaf disks. N° of reads with hits for total (DNA) and active OTUs (RNA) on leaf disks submerged in Oliveira Stream and Boss Brook, n = 6. (TIF)
Data
Maximum % contribution of each aquatic fungal taxon. Maximum % contribution was based on morphospecies sporulating on leaf disks submerged in Oliveira Stream and Boss Brook. (DOCX)
Data
Model parameters estimated for rarefaction curves. Rarefaction curves were based on alpha diversity measures (observed OTUs, Chao-1 richness index and Shannon diversity index) versus the sampling effort (sequencing depth). Michaelis-Menten models gave the best fits for these relationships (Eq 2). (DOCX)
Article
Full-text available
Traditional methods to identify aquatic hyphomycetes rely on the morphology of released conidia, which can lead to misidentifications or underestimates of species richness due to convergent morphological evolution and the presence of non-sporulating mycelia. Molecular methods allow fungal identification irrespective of the presence of conidia or th...
Data
Calculation of the limit of detection and limit of quantification. (DOCX)
Data
Description of DNA extraction, amplification, and sequencing. (DOCX)
Data
Description of the assays’ validation for environmental samples (DOCX)
Data
Theoretical validation of the qPCR assay’s specificity. (DOCX)
Data
Estimates of evolutionary divergences among sequences. (DOCX)
Article
Full-text available
Six Schiff base compounds have been prepared from the condensation of o-vanillin, 2,3-dihydroxybenzaldehyde and 2,3,4-trihydroxybenzaldehyde with 4-aminosalicylic acid and 5-aminosalicylic acid (5-ASA). Addition of these Schiff bases to [Pd(OAc)2] afforded the corresponding bis(salicylaldiminato)palladium(II) complexes in moderate to excellent yiel...
Chapter
This chapter focuses on quantitative methods to study the ecology of aquatic fungi. Specific objectives are to describe (1) techniques to determine the concentration of conidia and community structure of aquatic hyphomycetes in transport; (2) approaches for estimating reproduction (sporulation rate) of aquatic hyphomycetes; (3) methods to estimate l...
Article
Diversity, sporulation rates, and biomass of aquatic hyphomycetes (Kingdom Fungi) on leaf litter were examined to assess the effects of nutrient enrichment and flow regulation on the ecological integrity of the Saint John River, New Brunswick, Canada. Leaf decomposition rate was used as an indicator of ecological function, whereas fungal abundance...
Article
Full-text available
Mechanical and biological processing in aquatic systems converts coarse particulate organic matter (CPOM) into fine particulate organic matter (FPOM). Other sources of particles with different size classes include flocculated dissolved matter, algae and soil particles. The relative magnitudes of these inputs are influenced by the degree of allochth...
Research
Full-text available
Presentation at Annual Meeting of North American Benthological Society, San Marcos, Texas, 1997.
Article
Aquatic hyphomycetes have adapted to running waters by their uncommon conidial shape, which facilitates dispersal as well as adherence to plant substrata. However, they have been early and regularly reported to occur in a variety of environments other than their preferred habitat (e.g., in lentic freshwaters, brackish and marine environments, in te...
Article
Full-text available
Most streams receive substantial inputs of allochthonous organic material in the form of leaves and twigs (CPOM, coarse particulate organic matter). Mechanical and biological processing converts this into fine particulate organic matter (FPOM). Other sources of particles include flocculated dissolved matter and soil particles. Fungi are known to pl...
Article
Full-text available
A meta-analysis was performed to assess randomized controlled trials comparing local endovascular therapy (with and without intravenous thrombolysis) versus standard care (intravenous thrombolysis alone when appropriate) for acute ischemic stroke. Local endovascular therapy showed a significant improvement in functional independence versus standard...
Article
Full-text available
Most streams receive substantial inputs of allochthonous organic material in the form of leaves and twigs (CPOM, coarse particulate organic matter). Mechanical and biological processing converts this into fine particulate organic matter (FPOM). Other sources of particles include flocculated dissolved matter and soil particles. Fungi are known to pl...
Article
The reaction of [PdCl2(η2-coe)]2 (coe = cis-cyclooctene) with nine lipophilic iminopyridine ligands (NN′, 1a-i) afforded the corresponding metal complexes cis-[PdCl2(NN′)] (2a-i) with concomitant loss of the labile coe ligands. All iminopyridine complexes were characterized by physicochemical and spectroscopic methods. The molecular structures of t...
Article
The average global temperature is predicted to increase by 4 °C by the end of this century. Biotas of running waters, especially of low order streams, depend heavily on imports from the riparian vegetation. Autumn-shed leaves are decomposed and conditioned for invertebrate consumption by aquatic hyphomycetes. Overall metabolism, growth and reproduc...
Article
Terrestrial ecosystems are typically sustained by autochthonous primary producers, dominated by macrophytes, while small bodies of water depend heavily on leaves and twigs of allochthonous trees and shrubs. In addition, open waters allow growth of planktonic algae and bacteria. The relative scarcity of living macrophytes has inhibited the evolution...
Article
Full-text available
Ecological stoichiometry investigates how the ratios of elements in organisms shape their ecology and nutrient and energy fluxes in ecosystems. Despite their global distribution and essential roles in nutrient cycling, microbial decomposers are among the least known organisms in terms of elemental concentrations and stoichiometric relationships. Th...
Article
Full-text available
Since Ingold's (1942) initial description, mycologists have been interested in deciphering global distribution patterns of aquatic hyphomycetes, a group of fungi that play a key role in plant-litter decomposition in freshwaters. However, many questions remain largely unanswered. In this review, we used distribution data of morphospecies from studie...
Article
In 1942, Ingold documented an ecologically defined group of fungi, aquatic hyphomycetes, on autumn-shed leaves decaying in streams. They were shown to be vital intermediaries between the nutritionally poor leaf substratum and leaf-eating invertebrates. Research has subsequently emphasized functional aspects such as leaf decomposition and nutritiona...
Article
The reaction of Cu(II) sulfate or Pd(II) acetate with four salicylaldimines derived from 5-bromosalicylaldehyde and long-chain aliphatic primary amines afforded the corresponding metal complexes 2a-d and 3a-d, respectively. All complexes were characterized by physicochemical and spectroscopic methods. The molecular structure of 2b was determined by...
Article
To perform a meta-analysis of randomized controlled trials (RCTs) of drug-eluting balloon (DEB) angioplasty and drug-eluting stents (DESs) for infrainguinal peripheral arterial disease. Systematic searches were performed for all relevant RCTs. Eight RCTs for DEB angioplasty and 12 RCTs for a DES in peripheral arterial disease were identified. Meta-...
Data
On four dates spread evenly throughout 1991, leaves were collected at six sites near (within 25 m) and in a stream in Nova Scotia, Canada. Loose conidia were recovered by flotation and reproductive potential of aquatic hyphomycetes was estimated by an aeration technique. A total of 33 species with multiradiate or sigmoid spores were found at the fi...
Data
Aquatic hyphomycetes were isolated from living root tissues of spruce, birch and maple in a woodland stream of Nova Scotia by plating and aeration techniques. Of the 12 species recorded, Anguillospora filiformis and Heliscus lugdunensis were most common. Fungi were more common on bark than on decorticated segments. Aerated root segments yielded thr...
Data
Decomposition of Alnus glutinosa (alder) leaves was studied in a severely (site H4) and a moderately (site H8) heavy metal polluted stream in the former copper shale mining district of Mansfeld, Central Germany. Leaves at H8 had reduced fungal diversity and spore production but a high exponential decay rate (k = 0.065). No further mass loss of leav...
Article
Eight new fluoro- and methoxy-substituted benzodiazaborines have been prepared by a simple condensation reaction in high-to-excellent yields. All new compounds have been characterised by several physical methods, including X-ray diffraction studies on three examples. All new compounds were examined for antifungal activities against five species of...
Article
Full-text available
DNA barcoding is a rapid diagnostic approach in which short DNA sequences (ca. 600 bp) – the DNA barcodes – are used for species identification. Ideally, barcodes are sufficiently variable to distinguish closely related species and are flanked by conserved regions to allow the use of group-specific primers. Fungi play pivotal roles in ecosystems an...
Article
Detritivores preferentially consume certain aquatic hyphomycete species while rejecting others. Fungal identity may therefore be a crucial factor determining stream food-web structure and complexity and extend the impact of microbial diversity to effects up through the food web.In this study, we examined if shredder feeding is affected by the ident...
Article
Aquatic hyphomycetes play a key role in organic matter processing in freshwaters. Traditionally, species have been identified through the morphology of their conidia, but mycelia can fail to sporulate, making aquatic hyphomycetes a group where DNA barcoding is crucial. We generated ITS barcodes for nine aquatic hyphomycetes without published ITS se...
Chapter
Full-text available
Very broadly, the research we review in this chapter can be subdivided into bottom-up aspects (effects of the leaf-fungus complex on invertebrate consumers ) and top-down aspects(effects of invertebrate consumers on the leaf-fungus complex). Our goal was to distinguish between what is reasonably well established and where gaps in our knowledge or u...