Towards a consistent benchmark for plant mycorrhizal association databases

Abstract

Towards a consistent benchmark for plant mycorrhizal association databasesA reply to Soudzilovskaia et al. (2020) 'FungalRoot: global online database of plant mycorrhizal associations'Mycorrhizal symbiosis, comprising functionally distinctive plant-fungus associations, mediates key plant population and community processes, and ultimately the functioning of terrestrial ecosystems (Tedersoo et al., 2020). It is estimated that c. 90% of the world's vascular flora forms mycorrhizal symbioses with soil fungi (Smith & Read, 2008;Brundrett & Tedersoo, 2018). Although this general estimate is probably adequate, there is a severe shortage of empirical information about mycorrhizal associations at the plant species level, with only c. 5% of the world's flora explored (Moora, 2014;Bueno et al., 2019b). Several database developments have emerged since the seminal work of Harley & Harley (1987; HH); extending both the number and the geography of plant species covered (Wang & Qiu, 2006, WQ; Akhmetzhanova et al., 2012, MID), and defining and describing some key mycorrhizal traits of plant species -'mycorrhizal type' and 'mycorrhizal status ' (Hempel et al., 2013, MF;Moora, 2014). Nonetheless, this expansion poses new challenges connected with the compilation of global data based on heterogeneous sources with different practical and conceptual frameworks (Bueno et al., 2019b;Kattge et al., 2020). Careful work developing consistent definitions and standardizing field and laboratory protocols is essential for harmonizing database content and avoiding critical inconsistencies (P erez- Harguindeguy et al., 2013;Schneider et al., 2019).Recently, Soudzilovskaia et al. (2020) presented the largest compilation to date of empirical information about mycorrhizal associations in plants based on scientific literature (FungalRoot). Although this is a valuable and unique effort, we note three critical aspects that seriously hamper consistent data harmonization and should be addressed before the FungalRoot database can be considered as a standard reference in the field. Namely: (1) conceptual inconsistency in the designation of plant mycorrhizal associations; (2) incoherent application of plant mycorrhizal trait concepts; and (3) limited transparency in the incorporation of expert opinion. As we explain below, these issues appear particularly problematic in the cases of arbuscular mycorrhizal (AM) and nonmycorrhizal (NM) plants, and perhaps of lesser concern in the cases of other mycorrhizal types. However, given the high share of AM and NM plant species in the previous largest mycorrhizal database (73.1% and 18.0%, respectively, in WQ) and in the FungalRoot database (76.6% for AM, 15.5% for NM), these are critical issues to be resolved.

Dark diversity at home describes the success of cross‐continent tree invasions

“…The first six traits were extracted from the TRY Plant Trait Database (Kattge et al, 2020). The Information about mycorrhizal type and status were collected from multiple sources (Akhmetzhanova et al, 2012; Bueno et al, 2021; Harley & Harley, 1987a, 1987b, 1990; Hempel et al, 2013; Soudzilovskaia et al, 2020; Wang & Qiu, 2006). The mycorrhizal type classification was simplified when complex to three levels: ectomycorrhiza (ECM), arbuscular (ACM) and dual (ECM+AM).…”

Mycorrhizas shape the evolution of plant adaptation to drought

“…The main mycorrhizal types included in the FungalRoot are the arbuscular mycorrhizal (AM), facultatively AM, ecto-mycorrhizal, dual ecto-mycorrhizal and AM, ericoid mycorrhizal, orchid mycorrhizal, and non-mycorrhizal, which follow the mycorrhiza definitions previously proposed (Brundrett, 2009; Brundrett & Tedersoo, 2018a). However, because these definitions are still in part a matter of debate (Brundrett & Tedersoo, 2018b; Bueno et al ., 2018; Bueno et al ., 2019; Brundrett, 2021; Bueno et al ., 2021), to address the issue of data uncertainty, I generated partially different dataset versions on mycorrhizal strategy using the relatively smaller Bueno dataset (described below in assembly of dataset versions). The Bueno dataset includes assignments of AM, ecto-mycorrhiza, ericoid mycorrhiza, and non-mycorrhiza for a total of 1,362 plant species.…”

Effects of dual mycorrhizal inoculation on Pinus strobus seedlings are influenced by soil resource availability

“…Recent debates suggest an urgent need to accurately categorize mycorrhizal host plant types; however, mycorrhizal interactions are complex and may vary along a spectrum of host compatibility rather than representing two distinct categories, host and non-host Tedersoo 2018, 2020;Sun et al 2018Sun et al , 2019Tedersoo et al 2019;Bueno et al 2019Bueno et al , 2021. For example, members of the Pinaceae primarily form ECM associations; however, some species have been shown also to form rudimentary interactions with AM fungi (Cázares and Trappe 1993;Horton et al 1998;Wagg et al 2008;Dučić et al 2009).…”