Influence of bark pH on the occurrence and distribution of tree canopy myxomycete species

Abstract

This study compares the occurrence and distribution of myxomycete species in the canopy of living trees and neighboring grapevines. Corticolous myxomycetes of three temperate forests in southeastern USA were studied on six tree species (30 trees) and grapevines (30 vines) to determine distribution and occurrence of myxomycete species relating to geographic location, host species, and bark pH. The double-rope climbing technique was used to access the canopy and sample bark up to 16.5 m. Bark samples were examined in 580 moist chamber cultures and 44 myxomycete species were identified representing 21 genera, averaging 3.0 +/- 2.1 species per sample site. Jaccard's coefficient determined community similarity between five individuals of six tree species, Acer saccharum, Fraxinus americana, Liquidambar styraciflua, Liriodendron tulipifera, Platanus occidentalis and Tsuga canadensis, and neighboring grapevines, Vitis aestivalis and V. vulpina. Vertical variation in species richness was significantly different only for Platanus occidentalis and might be attributable to flaking of bark with increasing height in the canopy. Tsuga canadensis and neighboring grapevines had greatest community similarity. Cribraria violacea was observed on all tree and grapevine species except T. canadensis and neighboring grapevines. Occurrence and species assemblages of myxomycetes were associated with bark pH, not geographic location. Bark of V. aestivalis (pH 4.5) was more acidic than neighboring T. canadensis (pH 4.1), compared to grapevines of the same species neighboring other tree species. Results indicated that most species are not regionally restricted, and although some myxomycetes are associated with a certain pH range, others develop on any substratum. Future research protocols for corticolous myxomycetes should emphasize sampling adequate amounts of substrata in a local region from different host species that have a wide range of bark pH, ensuring a representative sample of species for an entire region.

Fungal wood decomposer activities influence community structures of myxomycetes and bryophytes on coarse woody debris

“…Brown rot is known to lower wood pH (Espejo and Agosin, 1991), and habitat pH is a primary determinant for many organisms (Partel et al 2004). Several field studies have shown that substratum pH is an important factor for myxomycete communities and that species of the genus Cribraria occur preferentially in acidic environments (Schnittler et al 2006;Rojas and Stephenson, 2007;Everhart et al 2008;Takahashi and Tsukiji, 2013). Although laboratory studies have shown the influence of pH on zygote formation (Shinnick et al 1978), plasmodium formation (Collins and Tang, 1973), and sporulation (Gray and Alexopoulos, 1968) of certain species of myxomycetes, it remains unclear why Cribraria species prefer acidic conditions.…”

Evolution of the plankton paleome in the Black Sea from the Deglacial to Anthropocene

“…Groupings were highly significant (P < 0.001, permutational multivariate ANOVA), and 25% of the variance in community structure was explained by the environmental stage. Furthermore, indicator species analysis (ISA) (33) showed that 150 out of 2,710 unique OTUs responded significantly (P < 0.05) to the Holocene environmental changes in the Black Sea (Fig. 2 and SI Appendix, Table S3).…”

Host tree bark traits and development of reintroduced Cattleya intermedia (Orchidaceae) plants in Southern Brazil

“…The present study demonstrated that factors such as solvent volume and suspension time of the bark influence the final pH values obtained. The distilled water used in the experiments had initial pH adjusted at 7.0, as mentioned by other studies (Everhart et al 2008(Everhart et al , 2009, and less the time the bark was maintained in solution, higher the pH values were. The solution acidifies over time, possibly due to continuous cation exchange between the bark and the solvent.…”

“…As an alternative, flathead electrodes can be used and their higher cost is their main disadvantage (Kricke 2002). Thus, there are studies that use larger solvent volumes, which may be 10 (Fritz & Heilmann-Clausen 2010), 16 (Suchara 2012) or 20 mL (Öztürk & Oran 2011) of deionized or distilled water, or even higher, such as those developed by Everhart et al (2008Everhart et al ( , 2009, which suspended bark samples in 35 mL of deionized water for 24 hours. However, most studies do not standardize the liquid volume in relation to the bark volume.…”