Contributions to the bryological knowledge of ASPA 125, Fildes Peninsula, King George Island

Background With 29 Km2, the Fildes Peninsula is the largest ice free area in King George Island and probably in Antarctica. The region is house of six permanent bases including the only airport in the South Shetlands, which led to impacts on its original landscape and vegetation. In recognition for the need to protect natural values, an Antarctic Specially Protected Area (ASPA 125) was established in the region. Focused mostly on protecting the fossils, the ASPA also plays a role in protecting the vegetation but so far, the management plan for the area does not contain a list of moss species present there. Results We provided an updated study and checklist of mosses present in ASPA 125. A key to species identification and photographs of main morphological features are also available in this paper. Also, six new occurrences are reported for Fildes Peninsula. Conclusion Considering the scarce knowledge about specific local floras in Antarctica associated with highly impacted area, of which only a fraction is protected, it is suggested the necessity to invest in detailed sampling studies, as well as in a better understanding of the local floras interactions in Antarctica.


Background
The Fildes Peninsula (62°08′ to 62°14′S and 59°02′ to 58°51′W), located southwest on King George Island is the largest ice free area in the South Shetland archipelago. Its vegetation is composed by mosses, lichens and only two species of flowering plants [Deschampsia antarctica E. Desv. and Colobanthus quitensis (Kunth) Bartl.]. The first and only comprehensive checklist of mosses for the region listed 40 species [5], including Ardley Island, but not much is known about species distribution and conservation status.
Fildes Peninsula is also probably one of the areas with higher human impact in the South Shetlands, as it houses six permanent Antarctic Bases (Chilean stations Escudero, Frei and Fildes, Chinese station Great Wall, Russian station Bellingshausen and Uruguayan station Artigas), plus many refuges and modules. Dirt roads also exist connecting them, where you can also find an airport and a small village (Villa de las Estrellas), which includes small facilities like houses, postal office and a school.
Due to its proximity with South America, the area has become a major hub for tourism, logistics, scientists and whoever is coming back and forth from Antarctica. This leads to a high permanent concern on the negative impacts of such activities and how to comply with the environmental protection protocols in the region.
According to Annex V of the Environment Protocol, an ASPA is created to "protect outstanding environmental, scientific, historic, aesthetic or wilderness values, any combination of those values, or ongoing or planned scientific research" (ATS 2016). The ASPA 125 was created due to its unique fossil composition, being probably the area with higher paleontological importance in Antarctica (ASPA 125 management plan, 2009). The region is divided on eight different regions or zones labeled as ASPA 125 a-h.
As the main goal of the area is to protect its fossil richness, not much has been done in order to better understand its floristic composition. As a result, the area management plan does not provide a list of the plant species present in the area, but only mentions the presence of 40 species of mosses, 175 lichens and 2 flowering plants. However, this list actually refers to a study area at the Fildes Peninsula and Ardley [5] and not to the ASPA at all, as a consequence the number and species composition of ASPA 125 remains unknown.
In this study we provide a list of all moss species occurring in Fossil Hill (ASPA 125a), providing a key to its identification and general comments for some taxa of the moss flora of the Fildes Peninsula.

Study area
Fossil Hill (ASPA 125a) is located at the south center of Fildes Peninsula, it is easily accessible by both Chinese Station and Chilean bases. It has an area of about 0.568 Km 2 (ASPA 125 management plan, 2009), and its higher elevations are ca. 130 m a.s.l. [5]. The area includes two main elevations: Büdel Hill and Fossil Hill.
ASPA 125a is the second largest zone after ASPA 125c, which is the buffer zone surrounding the Bellingshausen glacier dome, but it presents a more heterogeneous habitat and has marked altitudinal gradient.

Collections
Material was collected during the austral summer of 2017. Collections were made with the use of knife or by hand following the recommendations of Schofield [8]. Species were identified with the use of proper literature, especially Ochyra et al. [4]. Vouchers are preserved at herbarium UB [9] and classification system follows Goffinet et al. [3].

Fossil Hill checklist and identification key
Since there is no record of mosses specifically for the area, the list (Table 1) and key presented here are based solely on our own collections.

Illustration
Specimens were dissected and important morphological characteristics were photographed under light microscope using a coupled camera to capture the images. Those were edited and assembled in two plates to illustrate the species (Figs. 1 and 2).

Fildes Peninsula checklist
We used the checklist provided by Peter et al. [5] and compiled data from Ochyra et al. [4] as base for the list.

Table 1 Checklist of moss species in ASPA 125a, Fossil Hill, Fildes Peninsula
Taxa are systematically organized according to Goffinet et al. [3]. Species photographs are indicated in parenthesis a Indicates new occurrence for Fildes Peninsula

Moss families and their respective species
Amblystegiaceae Sanionia uncinata (Hedw.) Loeske (Fig. 1o,   We also checked for taxonomic updates, novelties and errors, resulting in the exclusion of some names. After that, we added data from our collections and updated the list for Fildes Peninsula (Table 2), following the classification system of Goffinet et al. [3]. For the family Pylaisiaceae, we followed the current concept of Câmara et al. [1].

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.  Scales a, f, i, l, o, r, s and v 500 μm; d, m and x 200 μm; c, h, p, q, t and u 100 μm; b, e, g, j, k, n and y

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 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 Km 2 contains almost 20% of all moss diversity in Antarctica. The Fildes Peninsula with about 1400 Km 2 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. Authors' contributions DKH collected and identified the samples, helped writing, illustrating and revising the manuscript. BGCS assisted in collection and revision of manuscript. GEZ provided the logistics and equipment in Fildes Station for collections and identification of samples and revised the manuscript. PEASC is the coordinator of Brazilian project "Evolution and Dispersion of Bipolar Antarctic Species of Mosses and Lichens" from where this paper originated, he wrote the manuscript, as well as collected and identified samples. All authors read and approved the final manuscript.