The distribution, ecology, and life history of Buxbaumia aphylla Hedw. in Newfoundland

Hancock, James A. (1973) The distribution, ecology, and life history of Buxbaumia aphylla Hedw. in Newfoundland. Masters thesis, Memorial University of Newfoundland.

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Abstract

The moss Buxbaumia aphylla has been found at 75 localities in southeastern Newfoundland and 2 localities on the west coast of the island, mostly in open Kalmia heaths on thin, acid (pH 5) humus. It is very abundant at 13 sites, moderately abundant at 24 sites, and scarce at 40 sites. The species' density, associated plant species, and fire succession have been recorded at some sites where the species was particularly abundant. -- The mineral element content of plant tissues and substrate were analyzed and represent the first data for bryophyte sporophytes. Almost all elements found in gametophytes were found in the sporophyte of- Buxbaumia aphylla. -- Silver, previously found only In Polytrichum and Atrichum, was found in Buxbaumia. -- Permanent plots enabled observations to be made on annual production of sporophytes and on their development and maturation. Sudden frosts appear to have adverse effects on development, often resulting in high mortality of capsules. The first plants of a hew sporophyte generation appear in mid-September but do not mature until the following June, overwintering, as immature capsules. Spore dispersal begins in mid-June. From September to June twelve morphological stages of sporophyte development are recognized. -- Protonemata of Buxbaumia aphylla were maintained in culture for ten months without producing sex organs, but possible asexual propagules were observed. – Of three possible theories to explain the life history of Buxbaumia aphylla, the most likely is that the protonemata persist from year to year producing new sporophytes each September. This would refute the assumption that B. aphylla is an annual moss and possibly indicate that it is actually a biennial or perennial moss.

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