Ecology of the Pteridophytes on the Southern Slopes of Mt. Kilimanjaro. Part II: Habitat Selection
Ecology of the Pteridophytes on the Southern Slopes of Mt. Kilimanjaro. Part II: Habitat Selection
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乞力马扎罗山南坡蕨类植物生态学。
DOI：
10.1055/s-2001-17729
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发表时间：
2001
期刊：
影响因子：
3.9
通讯作者：
A. Hemp
中科院分区：
文献类型：
--
作者：
A. Hemp
通过对乞力马扎罗山南坡957个植被样地的评价，对140种蕨类植物的生境偏好进行了评价。利用平均盖度值，综合考虑蕨类植物区系组成、生命形态谱及其季节生长格局谱，识别出8种植被组。盐沼、原始植被、草原和（亚）高寒石楠地蕨类植物对植被覆盖的贡献率不足1%。而蕨类植物是岩石上最重要的维管植物类群，共发现64种，约占植被覆盖的三分之二。在α和β多样性和蕨类生物量方面，茂密的山地林是乞力马扎罗山蕨类植物的主要栖息地。这里有130种蕨类植物（占研究区全部蕨类植物区系的93%），平均占植被覆盖总量的16%。附生蕨类、乔木蕨类和覆膜蕨类主要分布在海拔1900 ~ 2400 m之间，与乞力马扎罗山南坡降雨量最大的区域重合。
: Based on the evalutation of 957 vegetation plots on the southern slope of Mt. Kilimanjaro, habitat preferences for 140 species of pteridophytes were evaluated. Using the average percentage cover value, and taking into account the pteridophyte flora's composition, life form spectra and its spectra of seasonal growth pattern, eight vegetation formations were recognized. Ferns contributed less than 1 % of the vegetation cover of salt marshes, ruderal vegetation, grasslands and (sub-)alpine heathlands. In contrast, pteridophytes constituted the most important vascular plant group on rocks, where 64 species were found, forming about two-thirds of the vegetation cover. With respect to alpha and beta diversity and fern biomass, luxuriant montane forest was the main habitat for pteridophytes on Mt. Kilimanjaro. Here 130 pteridophyte species (93 % of the whole pteridophyte flora of the study area), on average, contributed 16 % of the total vegetation cover. Epiphytic ferns, tree ferns and filmy ferns had their main distribution between 1900 and 2400 m, in a zone coinciding with the maximum rainfall on Mt. Kilimanjaro's southern slope.
Poikilohydrous species were typical of dry habitats, such as on rocks, in meadows or along roadsides, but they also occurred in the often sun-exposed epiphyte layer in moist montane forests. Deciduous species, which were in many cases fire resistant, had a similar distribution; however, inside the forest belt they were restricted to the lower and upper parts, where fires are a common phenomenon. Evergreen species were the dominant group in swamps, forests and forest clearings.
Compared to other volcanoes in East Africa, Mt. Kilimanjaro is distinctly richer in fern species in general and in filmy ferns, tree ferns and epiphytic ferns in particular, suggesting that the forest belt of the southern slope of Mt. Kilimanjaro is wetter than those of other high mountains in East Africa.