The relationship between epixylic bryophyte communities and microclimate

Abstract

Aim Dead wood‐inhabiting bryophyte communities are formed by several important factors. Besides the amount, quality and continuity of the substrate, there are also external factors indirectly influencing their structure. One of the most important is local microclimate. This fact has been recognized by many previous authors, yet studies exploring the direct effect of the microclimate on epixylic bryophytes are still sparse. Based on directly measured values of local temperature, air humidity and canopy openness (CO), we explored the associations between microclimate and epixylic bryophyte communities. Location Old‐growth mixed Fagus sylvatica‐Abies alba montane forest in the Czech Republic (West Carpathians). Methods The associations between microclimate and bryophyte communities were studied on 61 large logs of Abies alba in advanced decay stage. Air temperature and humidity were measured in three periods of the year 2017, CO was measured in leafless and leaf‐on periods. Water potential (Ψ) values were calculated from the data. The importance of the seasons was compared, the effect of microclimate variables on the species composition of logs was explored by canonical correspondence analysis. The effect on total cover and species richness was analyzed by linear models. Results Our analysis revealed a clear relationship between the communities and the microclimatic gradient. The most important factors for bryophyte composition were the spring and summer water potential and CO in the leaf‐on period. Total species richness and cover increased with increasing water potential (relatively cool and humid conditions). Also, the appearance of sensitive epixylic specialists (mainly liverworts) was positively correlated with these microclimatic conditions. On the other hand, species more tolerant to desiccation preferred logs with a drier and warmer microclimate. Conclusions Comparing logs with similar physical properties but different microclimates, we confirmed that epixylic bryophyte communities are significantly associated to microclimatic conditions in natural temperate forest.

Projected shifts in deadwood bryophyte communities under national climate and forestry scenarios benefit large competitors and impair small species

“…Our study supported the hypothesis that habitat niche breath affects species’ vulnerability to climate change (cf., MacLean & Beissinger, 2017): the total habitat suitability for obligate deadwood species in Sweden decreased, whereas that for facultative species increased. Táborská et al (2020) similarly found that epixylic specialists in temperate forests were associated with low temperatures. Most likely, for obligate deadwood specialists, the loss of habitat at the (southern) trailing‐edge cannot be balanced by a gain of habitat at the leading‐edge, because the latter critically depends on the concomitant range shifts of suitable host trees (cf., Berg et al, 2010; Buckley & Kingsolver, 2012).…”

“…study supported the hypothesis that habitat niche breath affects species' vulnerability to climate change (cf.,MacLean & Beissinger, 2017): the total habitat suitability for obligate deadwood species in Sweden decreased, whereas that for facultative species increased Táborská et al (2020). similarly found that epixylic specialists in temperate forests were associated with low temperatures.…”

Epixylic diversity in an old-growth boreal forest is influenced by dynamic substrate attributes

“…This can be explained by a corresponding decrease of air moisture. Some species, especially true epixylics, have been reported to be drought-sensitive (Söderström, 1988b;Laaka, 1993;Proctor et al, 2007;Táborská, Kovács, Németh, and Ódor, 2020;Kropik et al, 2021). High water availability in deadwood is important for spore germination of epixylic bryophytes (Wiklund and Rydin, 2004).…”

Reduced-Impact Logging Maintain High Moss Diversity in Temperate Forests

“…This site is the oldest, with less logging area, and presents the highest humidity compared with the rest of the evaluated management sites. An old forest keeps conditions such as humidity and unique subtracts necessary for some species [104,105]. Other studies in boreal forests indicated that differences in the intensity disturbance could change the bryophytes species composition over time [106].…”