Ecology of the endangered species Solidago shortii. VI. Effects of habitattype, leaf litter, and soil type on seed germination

Solidago shortii T. & G. (Asteraceae) is a federal-endangered species endem ic to a small area in northeastern Kentucky. Seeds sown in December 1994 in a Festuca arundinacea-dominated meadow, in two Juniperus virginiana stands , and in an oak-hickory forest germinated to 39-59% in spring 1995; those s own in gaps of a J. virginiana stand and in the open germinated to 48-66%. Peak germination occurred before the oak-hickory canopy leafed-out and befo re F. arundinacea produced new (green) growth. Seeds covered with leaf litt er either immediately after sowing (on 23 December 1994) or 40 d after sowi ng germinated to 79-87% in spring 1995; those kept free of litter or with l itter removed 40 d after being covered with litter germinated to 58%. Only seeds continuously covered with litter from time of sowing germinated (3%) the second spring. In the laboratory, cold-stratified (nondormant) seeds ge rminated to 96-100% after 2 wk incubation at a 12/12 h daily thermoperiod o f 30/15 degrees C on soil derived from sandstone, black shale, dolomite, ca lcareous shale, and phosphatic limestone. These and previously-published re sults show that seeds of S. shortii germinate over a broad range of environ mental conditions; thus, this phase of the life cycle probably does not con tribute to the narrow endemism of the species.