The Fate of Bryophyte Sporophytes—Phenology and Vectors of Buxbaumia viridis in the Kalkalpen National Park, Austria

Abstract

Knowledge about the epixylic moss Buxbaumia viridis has increased significantly due to the monitoring obligation under the Habitats Directive. However, there are still open questions about its dispersal, as the wind plays a limited role in forest ecosystems, and vectors have been suspected but not yet studied systematically for this species. Here, we present data on potential vectors of Buxbaumia viridis collected for the first time with the help of cameras, completed by monitoring the fate of sporophytes during their life cycle in the Limestone Alps National Park in Austria over a period of two years. Young, green sporophytes appeared mainly in autumn, with the highest number in October. Most of them survived winter and spring but did not exceed the age of 14 months. The sharpest decline in capsules occurred in summer when mature, and the lowest number of sporophytes appeared at the end of August. Most likely, mice seem to be responsible for this loss, as the photos from the wildlife cameras suggest, and should be considered both as predators and vectors. Birds should be considered as vectors, too. In summary, most of the reproductive biomass is sacrificed in favor of more effective dispersal, including over longer distances.

Climate Variables Outstrip Deadwood Amount: Desiccation as the Main Trigger for Buxbaumia viridis Occurrence

“…(36), Larix decidua Mill. (8), and Pinus nigra J.F.Arnold (8). Buxbaumia viridis was found at all decay stages [23] between 1 and 5, with the highest frequency in decay stages 3 and 4.…”

“…The same is for numerous other rare epixylic bryophytes [ 20 ]. Awareness of the importance of deadwood as a diversity hotspot and refuge for rare and threatened species has increased [ 21 , 22 ], but the isolation of deadwood-rich forests at the landscape scale should also be considered as a severe threat for Buxbaumia viridis which was assumed to be dispersal-limited [ 6 , 8 , 39 ] like numerous other rare epixylic bryophytes [ 40 ].…”

“…It is also subject to the monitoring obligation of the Habitats Directive. While its life cycle [ 1 , 2 ], substrate preferences [ 3 , 4 , 5 , 6 ], seasonal variations in occurrence [ 3 , 6 , 7 , 8 ], and distribution [ 9 ] are well documented, we lack a solid understanding of the factors that control its distribution.…”

New Finds and Ecology of the Rare Liverworts Scapania apiculata, Scapania carinthiaca, and Scapania scapanioides in Austria

“…Compared with terrestrial habitats, where dispersal capacity is usually limited to a few centimetres [38,42,43], water overcomes long distances; however, dispersal remains confined further down the watercourse, and the contribution of a coincidence to finding an adequate deadwood log is very high. The extent to which animal vectors, as assumed in a few previous studies [44,45], are relevant for dispersal may also play a role in the target species' colonisation of new stream systems, and concerning upstream dispersal, this requires a focused investigation. Dispersal by spores seems to occur only in exceptional cases, at least in the Austrian growing sites.…”

Occurrence of the Green Shield-Moss Buxbaumia viridis (Moug.) Brid. in the Bieszczady Mountains of Poland

“…In previous years, there has been increasing interest in B. viridis, mostly due to the establishment of the Natura 2000 network in Europe, which has led to the identification of numerous new localities of the moss including in Poland [19,20], Slovakia [1,21,22], Czechia [23], Hungary and other EU countries [16]. This phenomenon has been highlighted by Plášek [24], Chachuła and Vončina [25], Cykowska and Vončina [26], Vončina [1], Paciorek [21], and Kropik et al [27]. These new findings have come from studies that were limited in terms of area and the number of workers engaged; however, they seem to suggest that this species may not be as rare in Poland as previously thought [28].…”