Pastures with sycamore
trees are biodiversity hotspots. In fact, botanist Thomas Kiebacher from the Swiss
Federal Research Institute WSL has found out
that these traditionally cultivated landscapes are home to over 500 species of
mosses and lichens. More than 50 of
these species are on Red Lists for endangered species. Therefore sycamore pasture conservation is needed.
Fig. 1 - A sycamore pasture in the Grosser Ahornboden nature reserve in the Austrian Tyrol. Click to enlarge.
Photo: Thomas Kiebacher (WSL)
doctoral thesis, Kiebacher investigated the mosses and lichens growing on
around 90 trees in alpine sycamore pastures. "The aim of the research
project was to gain a clearer understanding of the ecological requirements of
mosses and lichens and how we can take targeted measures to protect them.
Because around 40% of all mosses and a third of all tree- and ground-dwelling
lichens in Switzerland are endangered", says Kiebacher.
The researcher would also like to help conserve sycamore pastures because these park-like landscapes bear witness to a centuries-old cultivation method, which not only used these green spaces as pasture land, but also gathered the trees' foliage for use as bedding in cowsheds and their wood for heating. Yet many of these cultivated pastures have already been lost, and "today dead sycamores are rarely replaced like they used to be", Kiebacher was told by older local farmers when he asked them how the use of sycamore pastures had changed over the past century.
Fig. 2 - Rudolph's trumpet moss (Tayloria
rudolphiana) is a rare species that is protected throughout Europe and occurs almost exclusively on sycamores.
Photo: Thomas Kiebacher (WSL)
Over a two-year period, Kiebacher collected more than 20,000 moss and lichen samples from six locations in Switzerland, Austria and Germany. His results have now been presented in a number of specialist studies.
Kiebacher's research shows that about a fifth of all mosses and lichens known in Switzerland grow in sycamore pastures. In all, he identified 314 mosses and 232 lichens, more than 50 of which are endangered. Furthermore, on a number of sycamore trees the botanist found Rudolph's trumpet moss (Tayloria rudolphiana), a rare species that is protected throughout Europe and occurs almost exclusively in the northern Alps. Consequently, Switzerland bears great responsibility for conserving this species.
Fig. 3 - Location of the six study sites in the northern Alps. Base map: Lencer, Wikipedia, Creative-Commons
GA: Grosser Ahornboden, Tyrol, municipality of Vomp
GT: Glemmtal, Salzburg, municipality of Saalbach-Hinterglemm
GN: Gnadenalm, Salzburg, municipality of Untertauern
MG: Meniggrund, canton of Bern, municipality of Diemtigen
RB: Reichenbachtal, canton of Bern, municipality of Schattenhalb and Grindelwald
WF: Wankerfleck, Bavaria, municipality of Halblech-Buching
To record as many of the trees' lichens and
mosses as possible, Kiebacher even climbed up into the treetops. These efforts
paid off, for a third of all mosses and even two-thirds of the lichens only
flourish in the trees' upper reaches, probably because that is where quite
particular environmental conditions prevail. "This finding is very
important. The crowns of trees should always be included in biodiversity
studies on tree- and ground-dwelling mosses and lichens", says Kiebacher,
one of only a few researchers to have used this special specimen-gathering
technique so far.
And it's not just the sycamore trees themselves that are bursting with biodiversity, but also the ground vegetation beneath them, for in total Kiebacher found almost 350 vascular plants and over 250 moss species there. The researcher explains the large variety of species in terms of the great diversity of conditions on pastureland sites, where the spaced-out trees produce a patchwork of sunny and shady spots.
Fig. 4 - Climbing for nature conservation: Thomas Kiebacher ascends into the crown of a sycamore tree to gather mosses and lichens.
Photo: Julia Ecker
Kiebacher found that the oldest sycamores had the greatest species diversity, though some species, like the endangered bristle moss (Orthotrichum rogeri), prefer to grow on young trees. Consequently, Kiebacher points out that "it is important to maintain trees of different ages if we want to encourage broad diversity and secure the long-term future of sycamore pastures".
researcher will sum up the results of his five years of research on sycamore
pastures in a book to be published in autumn 2017. He not
only hopes this will raise public awareness that sycamore pastures constitute a
hitherto neglected habitat type with great biodiversity, but also that more
sycamore pasture conservation projects will be implemented.