Search results
Results From The WOW.Com Content Network
Compared to other Sphagnum species, Sphagnum squarrosum retains fewer spores within its capsules after dispersal, resulting in greater spore release and wider distribution. [ 9 ] Research on island colonization reveals that S. squarrosum is an effective long-distance disperser, successfully establishing populations as far as 40 km (25 mi) from ...
Sporophytes are raised on stalks to facilitate spore dispersal, but unlike other mosses, Sphagnum stalks are produced by the maternal gametophyte. Tetrahedral haploid spores are produced in the sporophyte by meiosis, which are then dispersed when the capsule explosively discharges its cap, called an operculum , and shoots the spores some distance.
Sphagnum fimbriatum faces the same threats as other European wetland species: habitat drainage for agriculture, nutrient pollution from farming, dam construction, and peat extraction. The species shows more resilience than other bog-mosses through effective spore dispersal and colonisation.
A spore print is made by placing the spore-producing surface flat on a sheet of dark and white paper or on a sheet of clear, stiff plastic, which facilitates moving the spore print to a darker or lighter surface for improved contrast; for example, it is easier to determine whether the spore print is pure white or, rather, very slightly pigmented.
In leptosporangiate ferns, the fern catapults its spores 1-2 cm so they can be picked up by a second dispersal vector, often the wind. [4]Autochory is the dispersal of diaspores, which are dispersal units consisting of seeds or spores, using only the energy provided by the diaspore or the parent plant. [5]
Under moist conditions, the elaters curl tightly around the spore. The wet spores tend to stick to each other and to nearby surfaces because of surface tension. When conditions are dry, the spores no longer stick to each other and are more easily dispersed. At that time, the elaters uncoil to extend out from the spore and will catch air currents.
In mosses, the peristome is a specialized structure in the sporangium that allows for gradual spore discharge, instead of releasing them all at once. Most mosses produce a capsule with a lid (the operculum ) which falls off when the spores inside are mature and thus ready to be dispersed.
A simplified version of the Emerson soil dispersion test [3] can be completed in the field on a 20-minute to two-hour timescale. Laboratory tests used to diagnose a soil as dispersive focus on the cation exchange capacity of a soil sample and its cation breakdown.