Refine
Document Type
- Article (5)
Language
- English (5)
Has Fulltext
- yes (5)
Is part of the Bibliography
- no (5)
A project dealing with the hepatic and moss floras of New Guinea and the Solomon Islands has proceeded more than halfway. The revision of the flora is based on the study of ca 17000 specimens collected in 1981. Two new genera and ca 50 new species have been described in 33 published papers and seven manuscripts. Many families, genera and species not previously recorded for the area have been added to the flora. More than 300 names have been reduced to synonyms. The percentage of endemic species of liverworts (40 %) is higher than that of mosses (18 %). Most of the endemic species occur at elevations above 1700 m. The geological history of New Guinea suggests that these high altitude endemics may be relatively young, i.e. less than 10 million years old. The moss flora is more closely related to the floras of Indonesia and the Philippines and continental Asia than to that of Australia. This can be explained by plate tectonics. The altitudinal distribution of hepatic and moss floras partly coincides with the zonation of vegetation proposed earlier. Human influence on bryophyte floras is devastating but a part of the flora may survive in gardens and plantations.
Decomposing wood forms the substrate for special lignicolous, hygrophilous, and sciophilous plant communities. In a moist tropical forest, vegetation on this substrate consists mostly of bryophytes. The material gathered from Mt. Meru and the Usambara Mts. in Tanzania comprises 102 taxa or genera of bryophytes. Of these 86 taxa are mosses and 16 hepatics. They were collected from a number of rotten logs at different stages of decay both in primeval and in cultivated forests. The bryophyte vegetation on these logs was examined by use of quadrats 20 x 20 cm. A total of 71 taxa occurred in 51 plots.
The specimen represents a rather typical African form of this taxon. The marginal teeth of the leaf are small and the leaf cells near isodiametric, but on the basis of the clearly differentiated juxtacostal cells, the specimen belongs to var. rhynchophyrum. Two other tropical African species are Plagiomnium cuspidatum (Hedw.) T. Kop. and P. undulatum (Hedw.) T. Kop. which differ by having an acute or cuspidate leaf apex, which in P. rhynchophorum tends to be emarginate and apiculate, and having sharper and larger projecting marginal teeth on their leaves. The distribution of P. rhynchophyrum is mapped and African specimens listed in Koponen (1981).
In the genus Rhizomnium T. Kop. most taxa have a strong leaf border several cells broad and bi- to tristratose. Rhizomnium striatulum (Mitt.) T. Kop. belongs to that group. In Northeast China one population of R. striatulum was found with a very weak leaf border, and also the costa of these plants is weaker than is characteristic for the species. The deviating population is figured and its significance discussed. The distribution of R. striatulum is mapped.
Manual of tropical bryology
(2003)
Bryophytes belong to the oldest land plants. They existed already in the Palaeozoic 300 mio years ago in forms which were hardly different from the extant species. They remained relatively unchanged with relatively low evolution rates (and are thus often called a „conservative“ plant group), but could successfully establish themselves in an always varying environment from Devonian swamps to Permian forests, Mesozoic deserts and as epiphytes in Tertiary rainforests. They are not eaten by snails or insects, and are resistant against fungi and bacteria.