CONTRIBUTION OF STREAM DETRIVORES, FUNGI, AND BACTERIA TO LEAF BREAKDOWN BASED ON BIOMASS ESTIMATES

Linking species and ecosystems is currently one of the great challenges in ecology. To this end, we assess here the contributions of bacteria, fungi, and detritivorous invertebrates (shredders) to leaf litter breakdown, a key ecosystem-level process. We enclosed alder (Alnus glutinosa) and willow (Salix fragilis) leaves in coarse-mesh bags (5 g dry mass), placed them in a stream during peak leaf fall, and retrieved them periodically to determine leaf mass remaining and the biomass of leaf-associated organisms. Shredder biomass was derived from numbers and length–mass relationships, bacterial numbers and biomass were determined by epifluorescence microscopy, and fungal biomass was measured as ergosterol. In addition, conidial production of aquatic hyphomycetes was determined. Leaves decomposed rapidly with exponential breakdown coefficients k of 0.035 d−1 (alder) and 0.027 d−1 (willow). Leaves were also quickly colonized within the first 4 wk of decomposition, when shredder biomass reached 263 and 141 mg d...

[1]  M. Gessner,et al.  Comparison of ATP and Ergosterol as Indicators of Fungal Biomass Associated with Decomposing Leaves in Streams , 1993, Applied and environmental microbiology.

[2]  M. Gessner,et al.  IMPORTANCE OF STREAM MICROFUNGI IN CONTROLLING BREAKDOWN RATES OF LEAF LITTER , 1994 .

[3]  É. Chauvet,et al.  The impact of eucalypt on the leaf-associated aquatic hyphomycetes in Spanish streams. , 1997 .

[4]  K. Suberkropp,et al.  Fungal and Bacterial Production during the Breakdown of Yellow Poplar Leaves in 2 Streams , 1996, Journal of the North American Benthological Society.

[5]  M. Gessner,et al.  Use of solid-phase extraction to determine ergosterol concentrations in plant tissue colonized by fungi , 1996, Applied and environmental microbiology.

[6]  Keller Suberkropp,et al.  Microorganisms and Organic Matter Decomposition , 1998 .

[7]  J. Flannagan.  An Introduction to the Aquatic Insects of North America. , 1979 .

[8]  T. Cuffney,et al.  Experimental evidence quantifying the role of benthic invertebrates in organic matter dynamics of headwater streams , 1990 .

[9]  J. Webster,et al.  Diet and growth of a leaf-shredding caddisfly in southern Appalachian streams of contrasting disturbance history , 1997, Hydrobiologia.

[10]  M. Palmer,et al.  Linking species diversity to the functioning of ecosystems: on the importance of environmental context , 2000 .

[11]  T. Arsuffi,et al.  Selective feeding by shredders on leaf-colonizing stream fungi: comparison of macroinvertebrate taxa , 1989, Oecologia.

[12]  M. Gessner,et al.  Stable successional patterns of aquatic hyphomycetes on leaves decaying in a summer cool stream , 1993 .

[13]  F. Bärlocher.  The Ecology of Aquatic Hyphomycetes , 1992, Ecological Studies.

[14]  Jackson R. Webster,et al.  VASCULAR PLANT BREAKDOWN IN FRESHWATER ECOSYSTEMS , 1986 .

[15]  J. Lawton,et al.  Linking Species and Ecosystems , 1996 .

[16]  K. Suberkropp.  Relationships between growth and sporulation of aquatic hyphomycetes on decomposing leaf litter , 1991 .

[17]  J. Meyer,et al.  Multiple Trophic Levels of a Forest Stream Linked to Terrestrial Litter Inputs , 1997 .

[18]  M. Gessner.  Differences in processing dynamics of fresh and dried leaf litter in a stream ecosystem , 1991 .

[19]  É. Chauvet,et al.  Afforestation with Eucalyptus globulus and leaf litter decomposition in streams of northern Spain , 1998, Hydrobiologia.

[20]  J. Schimel,et al.  Rivers and Soils: Parallels in Carbon and Nutrient Processing , 1998 .

[21]  J. Ward,et al.  Detrital processing and associated macroinvertebrates in a Colorado mountain stream , 1980 .

[22]  J. Webster,et al.  Stream Organic Matter Budgets: An Introduction , 1997, Journal of the North American Benthological Society.

[23]  J. Lawton,et al.  Consequences of the reduction of plant diversity for litter decomposition: effects through litter quality and microenvironment , 2000 .

[24]  Robert C. Petersen,et al.  Leaf processing in a woodland stream , 1974 .

[25]  K. Suberkropp.  The influence of nutrients on fungal growth, productivity, and sporulation during leaf breakdown in streams , 1995 .

[26]  M. W. Oswood,et al.  Microbial activity during leaf decomposition in an Alaskan subarctic stream , 1984 .

[27]  F. Azam,et al.  Protein content and protein synthesis rates of planktonic marine bacteria , 1989 .

[28]  J. Aho,et al.  Interspecific Leaf Interactions during Decomposition in Aquatic and Floodplain Ecosystems , 1994, Journal of the North American Benthological Society.

[29]  G. A. Bird,et al.  Processing of elm and maple leaf discs by collectors and shredders in laboratory feeding studies , 1985, Hydrobiologia.

[30]  P. Boon,et al.  A review of methodology used to measure leaf litter decomposition in lotic environments: Time to turn over an old leaf? , 1991 .

[31]  M. Dobson,et al.  A perspective on leaf litter breakdown in streams , 1999 .

[32]  D. Tilman.  THE ECOLOGICAL CONSEQUENCES OF CHANGES IN BIODIVERSITY: A SEARCH FOR GENERAL PRINCIPLES101 , 1999 .

[33]  G. N. Herbst.  Effects of leaf type on the consumption rates of aquatic detritivores , 1982, Hydrobiologia.

[34]  A. Huryn,et al.  Length-Mass Relationships for Freshwater Macroinvertebrates in North America with Particular Reference to the Southeastern United States , 1999, Journal of the North American Benthological Society.

[35]  E. Dumnicka,et al.  Litter decomposition in a mountain cave water , 1996 .

[36]  R. Pearson,et al.  Factors affecting litter processing by Anisocentropus kirramus (Trichoptera: Calamoceratidae) from an Australian tropical rainforest stream , 1993 .

[37]  M. W. Oswood,et al.  Processing and macroinvertebrate colonization of detritus in an Alaskan subarctic stream , 1983 .

[38]  R. Davies,et al.  Processing of willow leaves in two Alberta Rocky Mountain streams , 1984 .

[39]  G. Tillmanns,et al.  Physikalische, chemische und hydrographische Untersuchungen eines Mittelgebirgsbaches: Ein Beitrag zur Typisierung kleiner Fließgewässer , 1990, Aquatic Sciences.

[40]  Keller Suberkropp,et al.  Interactions with invertebrates , 1992 .

[41]  E. Pattee,et al.  Microbial dynamics on decaying leaves in a temporary Moroccan river. II - Bacteria , 1999 .

[42]  G. Minshall,et al.  River and stream ecosystems , 1995 .

[43]  J. Meyer,et al.  Leaf-shredding insects as a source of dissolved organic carbon in headwater streams. , 1983 .

[44]  J. Klima,et al.  Determination of Bacterial Cell Dry Mass by Transmission Electron Microscopy and Densitometric Image Analysis , 1998, Applied and Environmental Microbiology.

[45]  N. K. Kaushik,et al.  fate of the dead leaves that fall into streams , 1971 .

[46]  E. Grafius,et al.  Population Dynamics, Bioenergetics, and Role of Lepidostoma Quercina Ross (Trichoptera: Lepidostomatidae) in an Oregon Woodland Stream , 1979 .

[47]  Martin Solan,et al.  Consistent patterns and the idiosyncratic effects of biodiversity in marine ecosystems , 2001, Nature.

[48]  D. Padgett.  Leaf Decomposition by Fungi in a Tropical Rainforest Stream , 1976 .

[49]  M. Gessner,et al.  Ergosterol-to-Biomass Conversion Factors for Aquatic Hyphomycetes , 1993, Applied and environmental microbiology.

[50]  J. McArthur,et al.  Community Dynamics of Leaf Litter Breakdown in a Utah Alpine Stream , 1988, Journal of the North American Benthological Society.

[51]  S. Fisher.  River ecology and management: Lessons from the Pacific coastal ecoregion , 2000 .

[52]  J. Webster.  The Role of Benthic Macroinvertebrates in Detritus Dynamics of Streams: A Computer Simulation , 1983 .

[53]  S. Findlay,et al.  Microbial growth and detritus transformations during decomposition of leaf litter in a stream , 1989 .

[54]  Peter Burgherr,et al.  Regression analysis of linear body dimensions vs. dry mass in stream macroinvertebrates , 1997 .

[55]  B. Malmqvist,et al.  Ecosystem process rate increases with animal species richness: evidence from leaf‐eating, aquatic insects , 2000 .

[56]  É. Chauvet,et al.  Temperature and Sporulation of Aquatic Hyphomycetes , 1998, Applied and Environmental Microbiology.

[57]  M. Gessner,et al.  Bacteria, fungi and the breakdown of leaf litter in a large river , 1995 .

[58]  M. Gessner,et al.  Leaf litter breakdown in a Mediterranean stream characterised by travertine precipitation , 1999 .

[59]  M. Klug,et al.  The maceration of deciduous leaf litter by aquatic hyphomycetes , 1980 .

[60]  F. Rassoulzadegan,et al.  Use of high temperature catalytic oxidation (HTCO) to measure carbon content of microorganisms , 1999 .

[61]  J. Webster,et al.  The role of macroinvertebrates in stream ecosystem function. , 1996, Annual review of entomology.

[62]  K. Giller,et al.  Driven by Nature: Plant Litter Quality and Decomposition , 1996 .

[63]  B. Malmqvist.  Interactions in stream leaf packs : effects of a stonefly predator on detritivores and organic matter processing , 1993 .

[64]  E. Meyer,et al.  The relationship between body length parameters and dry mass in running water invertebrates , 1989, Archiv für Hydrobiologie.

[65]  D. J. D'Angelo,et al.  What happens to allochthonous material that falls into streams? A synthesis of new and published information from Coweeta , 1999 .

[66]  S. Y. Newell.  Estimating fungal biomass and productivity in decomposing litter , 1992 .

[67]  M. Heldal,et al.  Content of carbon, nitrogen, oxygen, sulfur and phosphorus in native aquatic and cultured bacteria , 1996 .

[68]  J. Ward,et al.  Trophic Ecology of Three Winter Stoneflies (Plecoptera) , 1981 .

[69]  M. Dobson,et al.  Colonisation of fresh and dried leaf litter by lotic macroinvertebrates , 1993 .

[70]  C. Otto.  Growth and Energetics in a Larval Population of Potamophylax cingulatus (Steph.) (Trichoptera) in a South Swedish Stream , 1974 .

[71]  F. Barlocher.  On Trophic Interactions between Microorganisms and Animals , 1979, The American Naturalist.

[72]  J. Cole,et al.  BACTERIAL GROWTH EFFICIENCY IN NATURAL AQUATIC SYSTEMS , 1998 .

[73]  Felix Bärlocher,et al.  Effects of leaf size and decay rate on colonization by aquatic hyphomycetes , 1983 .

[74]  M. Gessner,et al.  Rapid processing of fresh leaf litter in an upland stream , 1991 .

[75]  J. Sedell,et al.  Detritus Processing by Macroinvertebrates in Stream Ecosystems , 1979 .

[76]  R. Oremland,et al.  Use of “Specific” Inhibitors in Biogeochemistry and Microbial Ecology , 1988 .

[77]  M. Gessner,et al.  Leaf Breakdown in Streams of an Alpine Glacial Floodplain: Dynamics of Fungi and Nutrients , 1998, Journal of the North American Benthological Society.

[78]  K. Suberkropp.  Estimating production of litter-decomposing fungi in streams from rates of acetate incorporation into ergosterol , 2000 .

[79]  M. Gessner,et al.  Growth and production of aquatic hyphomycetes in decomposing leaf litter , 1997 .

[80]  John C. Fry,et al.  2 Direct Methods and Biomass Estimation , 1990 .

[81]  M. Gessner,et al.  Towards a budget of leaf litter decomposition in a first-order woodland stream , 1997 .