ES that reflects local climate, stream topography, hydraulics, and
Farrell, 2008). Altered thermal regimes promoted by anthropogenic activities, such as forestry practices (Johnson and
Jones, 2000; Moore et al., 2005), urbanization (Paul and Meyer, 2001; Nelson and Palmer, 2007), damming (Kinouchi, 2007;
Olden and Naiman, 2010), discharge from power plants and 9; Olden andNaiman, eier et al., 2003; Poff namic threats for a large number of watercourses. Interactive effects between the C by the end of the tressors can thus be henomena affecting streams e the most obvious ones include an increase in average water temperature and changes in precipitation and stream discharge, which frequently accentuate intermittency and/or floods (Murdoch et al., 2000; Schiller et al., 2011).
Stream water temperature is expected to follow air trends * Corresponding author. Tel.: þ351 239 240 784; fax: þ351 239 855 789.
E-mail address: firstname.lastname@example.org (C. Canhoto). available at www.sciencedirect.com
ScienceDirect els f u n g a l e c o l o g y x x x ( 2 0 1 5 ) 1e1 8URL: http://cfe.uc.pt/ccanhotostreambed characteristics (Poole and Berman, 2001; Caissie, 2006). In turn, it influences many other environmental parameters, e.g. solubility of gases and ions, and in-stream biological processes (Vannote and Sweeney, 1980; P€ortner and projected temperature increase of over 4 century (IPCC, 2014) and multiple local s expected, amplifying existing problems.
Global warming encompasses many pIntroduction
Temperature is a fundamental physical property of streams wastewaters (Durance andOrmerod, 200 2010), water abstraction or diversion (M et al., 2010), present prominent and dyArticle history:
Received 15 May 2015
Revision received 2 September 2015
Accepted 14 September 2015
Available online Corresponding editor:
Aquatic hyphomycetes [CO2]
Fungal reproduction and biomass
TemperaturePlease cite this article in press as: Canho climate, Fungal Ecology (2015), http://dx. http://dx.doi.org/10.1016/j.funeco.2015.09.011 1754-5048/ª 2015 Elsevier Ltd and The BritisThe 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 reproduction of these fungi will be directly affected by rising temperatures and associated changes. Both resource (leaves) and consumers/competitors (leaf-eating invertebrates) will react to the same changes; their responses may indirectly influence fungal activities.
Published studies on fungal reactions to climate change often reach contradictory and location-specific conclusions. Most commonly, at least in temperate streams, higher temperatures stimulate fungal metabolism, though there may be shifts in fungal allocations to enzyme activities, growth and reproduction. On a global scale, there is some evidence that rising temperatures will increase the contribution of aquatic hyphomycetes to litter processing in streams at the expense of invertebrates. ª 2015 Elsevier Ltd and The British Mycological Society. All rights reserved.a r t i c l e i n f o a b s t r a c taCentre for Functional Ecology, Department of Life Sciences, University of Coimbra, Calc¸ada Martim de Freitas, 3000-456, Coimbra, Portugal bDepartment of Biology, Mt. Allison University, Sackville, New Brunswick, E4L1G7, CanadaBiology and ecological function hyphomycetes in a warming c
Cristina CANHOTOa,*, Ana Lucia GONC¸ALV journal homepage: www.to, C, et al., Biology and doi.org/10.1016/j.funeco h Mycological Society. Alof aquatic mate a, Felix B€ARLOCHERb evier .com/locate/ funecoecological functions of aquatic hyphomycetes in a warming .2015.09.011 l rights reserved. providing the basis for “warm water fungal ecology”. Evalu1971; Gessner et al., 2007; Krauss et al., 2011).
Aquatic hyphomycetes are crucial links between the riparian vegetation and consumer communities. They enhance litter nutritional value and palatability of the leaf substrata to leaf-shredding invertebrates (Kaushik and Hynes, 1971; Cummins et al., 1973; B€arlocher and Sridhar, 2014).
Environmental factors such as temperature (Mas-Martı et al., 2015a), pH (e.g., Dangles and Chauvet, 2003), inorganic nutrients (e.g., Suberkropp et al., 2010) and light (e.g., Lagrue et al., 2011), acting independently or synergistically, strongly influence the biota’s phenology and physiology, with potentially crucial consequences for litter decomposition, nutrient cycling and stream productivity (Wipfli et al., 2007; Gessner et al., 2010; Krauss et al., 2011).
Stages in fungal mediated decomposition of litter: effects of warming
Litter colonization starts with the attachment of aquatic hyphomycete spores to organic matter (Table 1). This initial step is primarily affected by surface morphology and structure, and is a precondition for spore germination and hyphal invasion of the substratum (B€arlocher et al., 1977; Dang et al., 2007; Kearns and B€arlocher, 2008). 2 C. Canhoto et al.ating and predicting the impacts of global warming and associated extreme events on the aquatic biota and stream processes have become a major research theme in stream ecology (Liboriussen et al., 2005; B€arlocher et al., 2008; Fernandes et al., 2009; Perkins et al., 2010a,b; Woodward et al., 2010; Boyero et al., 2011; Friberg et al., 2013; Ferreira and
Canhoto, 2015; Ferreira and Voronina, in press). The ultimate goals are preservation or recovery of aquatic biota and their ecological functions (Gessner and Chauvet, 2002) and, by extension, of goods and services provided to humans (YvonDurocher et al., 2010). This paper aims at contributing to that objective by integrating traditional and recent information on the effects of rising temperature on aquatic hyphomycete biology and ecology in temperate heterotrophic streams.