![Hier klicken, um den Treffer aus der Auswahl zu entfernen](images/unchecked.gif) |
Titel |
Experimental investigation of the early interaction between cyanobacterial
soil crusts and vascular plants |
VerfasserIn |
Markus Klemens Zaplata, Maik Veste, Ina Pohle, Sabine Schümberg, Iballa Abreu Schonert, Christoph Hinz |
Konferenz |
EGU General Assembly 2016
|
Medientyp |
Artikel
|
Sprache |
en
|
Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 18 (2016) |
Datensatznummer |
250128594
|
Publikation (Nr.) |
EGU/EGU2016-8595.pdf |
|
|
|
Zusammenfassung |
While there are hints that biological soil crusts (BSCs) can constitute physical barriers for the
emergence of vascular plants, a conceptual approach for the quantitative evaluation of these
effects is still missing. Here we present an experimental design to test the emergence of
seedlings in situ with (i) capping natural intact, (ii) destroyed and (iii) removed BSC. The
selected field site is directly adjacent to the constructed Hühnerwasser catchment (Lusatia,
Germany). This site exists since the end of 2008 and consists of loamy sand. Serving as proxy
for seedling thrust, we inserted pre-germinated seeds of three confamiliar plant species with
different seed masses (members of the Fabaceae family: Lotus corniculatus L.,
Ornithopus sativus Brot., and Glycine max (L.) Merr.). In each treatment as well as in the
control group planting depths were 10 mm. We took care that experimental plots had
identical crust thickness, slightly less than 4 mm, serving as proxy for mechanical
resistance.
A plot became established as follows: Firstly, the pristine crusted surface was vertically
cut. To the windward side the BSC remained intact (i: “with BSC” stripe). To the downwind
side soil material was temporarily excavated for laterally inserting the seeds beneath the
surface of the first stripe. Then at the thereby disturbed second stripe pulverised BSC material
became filled as a top layer (ii: “BSC mix” stripe). From the next stripe the BSC was
removed (iii: “no BSC” stripe). Thus each plot had each experimental group in
spatial contiguity (within 50 cm × 50 cm). The overall 50 plots were distributed
across an area of 40 m × 12 m. When individuals of a species either emerged at all
stripes, “× × ×”, or at no stripe of a plot, “– – –“, there was no reason to
suppose any effect of a crust. The “– × ×” emergence pattern (depicting the
appearance of seedlings in both stripes possessing manipulated surfaces) points towards
hindrance more clearly than “– × –” or “– – ×”. Altogether eight possible combinations
exist.
Combinatorial analysis turned out that seedling emergence had been notably impeded for
light-weighted seeds but little for heavy seeds. Repeated recordings enable to account for
adaptable emergence of seedlings according to varying crust conditions – in spatial as well as
temporal terms. The proposed experimental procedure hence is highly recommended as a
viable instrument to further investigate filter and facilitation processes between BSCs and
vascular plants. |
|
|
|
|
|