Species on Fossil Hill
Twenty-one species divided in thirteen families of mosses are recorded for the ASPA 125a site (Table 1). This represents about 41% of what is reported for the Fildes Peninsula [5] and about 18% of the whole Antarctic moss flora. Considering the relatively small area of the site, it shows its high importance and the relevance of the site in protecting the vegetation.
Key to the moss species present at Fossil Hill
1. Plants Pleurocarpous … 2
1. Plants Acrocarpous … 4
2. Costa extending into apex, leaves strongly falcate … Sanionia uncinata
2. Costa ending below apex, leaves non falcate … 3
3. Leaves plane, oblong-ovate with rounded apex … Warnstorfia sarmentosa
3. Leaves strongly concave, ovate-lanceolate with acute to long-acuminate apex … Brachythecium austrosalebrosum
4. Costa absent … Andreaea gainii
4. Costa present … 5
5. Leaves with ventral lamellae in cross section … Polytrichastrum alpinum
5. Leaves without ventral lamellae in cross section … 6
6. Cells at leaf base differentiated, hyaline … 7
6. Cells at leaf base not differentiated, non hyaline … 11
7. Leaves with subula … Batramia patens
7. Leaves without subula … 8
8. Basal cells thick walled … Encalypta procera
8. Basal cells thin walled … 9
9. Transition from hyaline basal cells to chlorophyllose upper cells gradual, leaf base without border … Hennediella heimii
9. Transition from hyaline basal cells to chlorophyllose upper cells abrupt, leaf base with narrow border … 10
10. Costa percurrent, rarely short-excurrent, absence of hyaline hair point, leaves lanceolate to oblong-lanceolate, apex narrowly acute … Syntrichia saxicola
10. Costa always excurrent, presence of hyaline hair point, leaves ovate to ovate-lingulate, apex obtuse … Syntrichia caninervis
11. Leaves tightly appressed or crisped when dry; capsules immersed … 12
11. Leaves usually erect to erect-spreading, rarely crisped when dry; capsules emerged … 13
12. Leaf margins entire, apex forming a hair point … Schistidium andinum
12. Leaf margins serrulate to denticulate in the apex, apex not forming a hair point … Schistidium rivulare
13. Leaves distichous or not; leaf cells subquadratic, small lumen, thick walled … 14
13. Leaves never distichous; leaf cells hexagonal or fusiform, lax, thin walled … 16
14. Leaves always distichous … Distichium inclinatum
14. Leaves never distichous … 15
15. Leaves often forming a sheathing base, abruptly narrowed forming a long subula, leaf margins plane at least in the base … Ditrichum hyalinum
15. Leaves not forming sheathing base nor subula, leaf margins often strongly recurved throughout whole lamina … Ceratodon purpureus
16. Leaf apex shortly acute to obtuse, laminal cells quadratic to rectangular throughout … Meesia uliginosa
16. Leaf apex acute to apiculate, laminal cells hexagonal or fusiform … 17
17. Presence of leaf border … 18
17. Absence of leaf border … 20
18. Plants whitish, leaf base yellowish or green, costa subpercurrent … Bryum argenteum
18. Plants never whitish, leaf base red, costa percurrent to excurrent … 19
19. Costa percurrent to short-excurrent, leaves decurrent, acute to short acuminate … Bryum pseudotriquetrum
19. Costa long-excurrent, leaves non-decurrent, commonly long-acuminate … Bryum archangelicum
20. Costa brownish to red near leaf base, cells thin walled, upper laminal cells vermicular … Pohlia cruda
20. Costa dark green to brownish near leaf base, cells thick walled, upper laminal cells elongate-hexagonal … Pohlia nutans
Species for Fildes Peninsula
According to data presented here, together with previous reports for the same location, there are 48 species of mosses divided in 17 families in the Fildes Peninsula (Table 2). This represents about 43% of all mosses known to Antarctica [4].
Comments
Batramia patens Brid. It was only reported in Fildes for lake Kitiesh, but it is much more widely distributed in the Peninsula, including areas like Chilean Collins refuge, Uruguayan base Artigas, Fossil Hill and Chinese station Great Wall and its surroundings, being actually quite frequent. Putzke and Pereira [7] also reported it for Fildes, but the exactly location was not mentioned. Unfortunately we did not have the chance to study this material.
Conostomum magellanicum Sull. This species is not mentioned by Ochyra et al. [4] as occurring in Fildes Peninsula. We also did not collect it during our expedition and its report was maintained since it is present in Peter et al. [5].
Schistidium urnulaceum (Müll. Hal.) B.G. Bell. This species is not mentioned by Ochyra et al. [4] as occurring in Fildes Peninsula. We also did not find any sample of this taxon on our collections. Like C. magellanicum, it was maintained based on Peter et al. [5].
Final considerations
Mosses are the second largest group of land plants, second only by Angiosperms [3]. In Antarctica, where there is only two species of native Angiosperms, mosses are the dominant vegetation, being present in both continental and maritime Antarctica.
Mosses are well known as bioindicators and for producing chemicals with pharmacological potential [2]. Unfortunately, not much is known about its ecological role and conservation status, especially in Antarctica. Very few ASPA management plans have a comprehensive list of moss species in their area, limiting more complex studies regarding the group in these places.
Fossil Hill with only 0.568 Km2 contains almost 20% of all moss diversity in Antarctica. The Fildes Peninsula with about 1400 Km2 contains 43% of all moss diversity in Antarctica. The knowledge of these areas continues to expand, as six new occurrences were found in this study.
The low level of understanding of the local flora associated with a highly impacted area of which only a fraction is protected highlights the necessity to invest in broader and detailed sampling studies, as well as in a better understanding of the floras in specific areas, both protected and not.
Antarctica is a fragile system and the Fildes Peninsula is already a highly impacted place. It can be expected that changes in climate conditions associated with local human activities may disturb the flora, reinforcing the need of understanding the true moss diversity of this region and its relation to other sites in South Shetlands.