The Spatial Distribution of Fungi on Decomposing Woody Litter in a Freshwater Stream, Western Ghats, India

Abstract

We mapped filamentous fungal association with mechanically "hard" and "soft" woody litter naturally deposited in a stream of the Western Ghats of India. Using a durometer (rubber hardness tester), the toughness of surface of wood collected from stream was determined by considering durometer reading from 60-72 to 30-37 as hardwood and softwood, respectively. From each wood (1.5 cm diameter), two segments each of 3 cm length were excised and vertically cut into nine sections comprising eight marginal and one central section. From three stream locations, hardwood and softwood sections were assessed for the occurrence of lignicolous and Ingoldian fungi. A first set of wood sections was incubated in damp chambers up to 4 months with periodical screening (every 2 weeks) for lignicolous fungi. Another set was incubated in bubble chambers up to 72 h to ascertain colonization of Ingoldian fungi. In hardwood sections, 17 lignicolous fungi (ascomycetes, four; mitosporic fungi, 13; mean, 6.8; range, 6-8/section) and ten Ingoldian fungi (mean, 2; range, 0-4/section) comprising nine lignicolous (11.1-40.7%) and three Ingoldian (11.1-14.8%) fungi as core-group taxa were recovered. In softwood, ten lignicolous fungi (ascomycetes, 0; mitosporic fungi, ten; mean, 3.8; range, 2-5/section) and 26 Ingoldian fungi (mean, 8.1; range, 5-10/section) comprising six lignicolous (11.1-85.2%) and 12 Ingoldian (11.1-88.9%) fungi as core-group taxa were recovered. The ratio of lignicolous fungi/Ingoldian fungi was higher in hardwood than softwood (1.7 vs. 0.4). The spore output of Ingoldian fungi was higher in softwood (mean, 901 g(-1); range, 80-2546 g(-1)) than hardwood (mean, 21 g(-1); range, 0-140 g(-1)). The Shannon diversity of lignicolous fungi was higher in hardwood than softwood (3.604 vs. 2.665), whereas it was opposite for Ingoldian fungi (3.116 vs. 3.918). The overall fungal diversity was higher in softwood than hardwood (4.413 vs. 4.219). The range of Jaccard's index of similarity among wood sections was higher in lignicolous fungi (8-71% and 13-75%) than Ingoldian fungi (0-50% and 8-55%) in hardwood and softwood. The rarefaction indices of expected number of taxa against hardwood sections revealed higher and persistent lignicolous fungi than the Ingoldian fungi, while the Ingoldian fungi were persistent in softwood sections, although they were lower than lignicolous fungi. Our study demonstrated the dominance of lignicolous fungi and Ingoldian fungi in hardwood and softwood, respectively.

Small leaf breakdown in a Savannah headwater stream

“…Fungi and bacteria interact synergistically and antagonistically during leaf breakdown (Gulis and Suberkropp, 2003b;Sridhar and Sudheep, 2011). In the present study, the highest values of ATP were found in the final stages of decomposition, although with fluctuations over time and higher concentrations of ergosterol.…”

“…As shown in several studies (Gessner and Van Ryckegem, 2003;Krauss et al, 2011;Sridhar and Sudheep, 2011), the changes in physical and chemical characteristics of the detritus during the decomposition process may have changed the abundance of fungal species in the community, with fungi capable of degrading recalcitrant compounds becoming more abundant.…”

Substratum‐Associated Microbiota

“…Lotic fungal diversity was greater on softwood than hardwood. Jaccard's index of similarity was greater for in lignicolous fungi than Ingoldian fungi in hardwood and softwood, suggesting that lignicolous fungi dominated hardwood and Ingoldian fungi dominated softwood (Sridhar and Sudheep 2011). Fecal pellets of…”

Saprophytic synnematous microfungi. New records and known species for Mexico

“…Geographical distribution and substrate known: Phaeoisaria clavulata has been widely collected in different European localities (Ellis, 1971;Révay, 1986). There are also reports from Malawi (Sutton, 1993), India (Rao & De Hoog, 1986;Sridhar & Sudheep, 2011), Malasya (Cybernome, 2017) and Pakistan (Abbas et al, 2013). It is considered a lignicolous species.…”