ArticlePDF Available

Rapid denudation processes in cryptogamic communities from Maritime Antarctica subjected to human trampling

Authors:

Abstract and Figures

This study explores the impact of human trampling on moss and lichen dominated communities of Maritime Antarctica. A simulation of trampling was performed on previously unaffected plots of different terricolous cryptogamic assemblages at Byers Peninsula, Livingston Island. The communities studied were: 1) a uniform moss carpet, 2) a heterogeneous moss assemblage composed of hummocks and turfs, and 3) a fellfield lichen community. All communities analysed were extremely sensitive but different denudation processes were observed. None of the plots maintained 50% of initial coverage after 200 pedestrian transits. Even very low trampling intensity resulted in disturbance at all plots. Sensitivities of the different communities were identified in order to formulate recommendations for minimizing the trampling impacts. In our study the lichen dominated community on dry exposed soils exhibited the lowest resistance to trampling. For moss communities, lower resistance was found in peat soils with higher water content and biomass. With the current trend of increasing human presence in Antarctica, we predict that the cumulative impacts of trampling over future decades will adversely affect all types of moss and lichen communities.
Content may be subject to copyright.
Antarctic Science 25(2), 318–328 (2013) &Antarctic Science Ltd 2013 doi:10.1017/S095410201200082X
Rapid denudation processes in cryptogamic communities from
Maritime Antarctica subjected to human trampling
L.R. PERTIERRA
1
, F. LARA
2
, P. TEJEDO
1
, A. QUESADA
2
and J. BENAYAS
1
*
1
Dpto. Ecologı
´a, Universidad Auto
´noma de Madrid, c/ Darwin 2, 28049 Madrid, Spain
2
Dpto. Biologı
´a, Universidad Auto
´noma de Madrid, c/ Darwin 2, 28049 Madrid, Spain
*Corresponding author: javier.benayas@uam.es
Abstract: This study explores the impact of human trampling on moss and lichen dominated communities of
Maritime Antarctica. A simulation of trampling was performed on previously unaffected plots of different
terricolous cryptogamic assemblages at Byers Peninsula, Livingston Island. The communities studied were:
1) a uniform moss carpet, 2) a heterogeneous moss assemblage composed of hummocks and turfs, and
3) a fellfield lichen community. All communities analysed were extremely sensitive but different denudation
processes were observed. None of the plots maintained 50% of initial coverage after 200 pedestrian transits.
Even very low trampling intensity resulted in disturbance at all plots. Sensitivities of the different
communities were identified in order to formulate recommendations for minimizing the trampling impacts. In
our study the lichen dominated community on dry exposed soils exhibited the lowest resistance to trampling.
For moss communities, lower resistance was found in peat soils with higher water content and biomass. With
the current trend of increasing human presence in Antarctica, we predict that the cumulative impacts of
trampling over future decades will adversely affect all types of moss and lichen communities.
Received 27 January 2012, accepted 11 July 2012
Key words: fellfield soils, human impact, management, moss and lichen communities, recreation ecology,
trampling simulation
Introduction
Bryophyte and lichen communities constitute one of the
few types of terricolous vegetation in Maritime Antarctica,
being especially developed in favourable coastal locations.
Ice-free areas of coastal sites experience most of the human
impact from ship-borne tourism and scientific research on
the Antarctic Peninsula and offshore islands (Lynch et al.
2010, Hughes et al. 2011). Therefore terrestrial vegetation
is especially vulnerable to human foot traffic. The increase
of visitors to the Antarctic has been exponential during
the last twenty years with cumulative trampling impacts
detected at or near tourist landing sites (Bastmeijer &
Roura 2004) and around scientific field camps (Tejedo
et al. 2009). Increased human presence is relatively well
documented. Data on national research programmes
activities are available on the Antarctic Treaty Secretariat
(ATS) website (http://www.ats.aq/e/ie.htm). Information on
tourist visits is published on the International Association
of Antarctica Tour Operators (IAATO) website (http://
iaato.org/es/tourism-statistics). Tourist visits are largely
concentrated in the Antarctic Peninsula region. Tourists
arrive on cruise ships and make shore visits on the ice-free
coastal zones of two to three hours each, one to three times
daily (Bertram 2007). Scientific expeditions are far more
widespread along the Antarctic Peninsula, as personnel can
work out of stations, ships or field camps (Hughes et al.
2011). As a result, both diffuse and concentrated trampling
patterns can be expected to result from human activities on
the Antarctic Peninsula.
Other factors, such as climate change (Vaughan et al.
2003, Turner et al. 2005) and human induced biological
invasions (Frenot et al. 2005, Hughes & Convey 2010),
could act in synergy with the deterioration of terrestrial
ecosystems resulting from trampling (Smith 1994, Olech
1996, Smith & Richardson 2011). Moreover, other human
activities could also have indirect effects. For example, in
the case of the South Orkney Islands, sealing activities
in the 18th century may have indirectly led to the severe
damage to vegetation caused by expanding fur seal
populations (Smith 1988). Available knowledge on the
effects of trampling in the Antarctic is currently rather
sparse (Tin et al. 2009, Convey 2010).
This study offers a first attempt to assess the sensitivity
of bryophyte and lichen terricolous communities under
experimental trampling conditions in Antarctica. Previous
studies of trampling on bare soils conducted by Ayres et al.
(2008) in the McMurdo Dry Valleys showed that even low
levels of human traffic could produce impacts on soil biota.
Tejedo et al. (2005, 2009) developed indicators and measured
the effects of experimental trampling on bare soils on Byers
Peninsula. On Cuverville Island, de Leeuw (1994) and Beyer
&Bo¨lter (2002) reported that low trampling intensities
rapidly led to disturbances to terrestrial vegetation. Thor
(1997) and Johansson & Thor (2008) studied the possible
impacts of human activities on terrestrial vegetation around
318
research stations in Dronning Maud Land and reported
no severe damage but a decline in the number of lichen
species. In our study area, the South Shetland Islands,
significant damage to terrestrial vegetation has already been
documented at sites with a high concentration of scientific
stations, such Fildes Peninsula, King George Island (ASOC
2004), or tourist visited sites such Barrientos Island, Aitcho
Archipelago (Ecuador & Spain 2012).On a larger scale,
Scott & Kirkpatrick (1994) conducted studies of the effects
of trampling on the biodiversity of sub-Antarctic Macquarie
Island. Also in the sub-Antarctic, Gremmen et al. (2003)
examined the different habitats crossed by paths on Marion
Island. In the Arctic, West & Maxted (2000) examined the
effects of trampling around field camps in Svalbard. To our
knowledge, no experimental trampling studies focused on
the sensitivity of cryptogamic formations have been
performed in the Antarctic Peninsula.
Experimental trampling studies of vegetation have been
frequently conducted in more temperate areas (Cole &
Bayfield 1993, Cole 1995a, 1995b, Marion & Cole 1996,
Marion & Leung 2001, Farrell & Marion 2001, 2002),
providing an extensive framework of procedures. The specific
aim of the current study is to measure the resistance capacity
of different Antarctic terricolous cryptogamic communities
to human trampling. The resistance of vegetation to
trampling is defined by the amount of damage in terms of
cover loss caused by a given trampling intensity (Cole &
Bayfield 1993). To this end, we used a linked set of
indicators and field observations. Our objectives were to
identify effective indicators for assessing the consequences
of trampling on cryptogamic vegetation, and to estimate
the magnitude of this impact on different bryophyte and
lichen communities. With this study, we hope to advance
our baseline knowledge on crytogamic formations in the
Antarctic Peninsula, contribute towards minimizing the
environmental impacts of scientific expeditions, and alert
the scientific community to the challenges faced by these
most sensitive plant formations in the context of increased
human activity in the Antarctic.
Material and methods
Description of the study area
Byers Peninsula is situated on the western side of Livingston
Island (62834'35''–62840'35''S, 60854'14''–61813'07''W) and is
Fig. 1. Study site at Byers Peninsula ASPA No. 126 topographic map (modified). Inset: the location of the three cryptogamic
communities in the South Beaches of Byers Peninsula. Source: ASPA 126 Management Plan, Byers Peninsula (Map 2).
TRAMPLING EFFECTS ON CRYPTOGAMIC COMMUNITIES 319
the largest ice-free area in the South Shetland Islands
(Lo´pez-Martinez et al. 1996). Its numerous freshwater
bodies are of interest for limnological studies (Quesada
et al. 2009). The periglacial landscape comprises tens of
lakes and streams with diverse biological conditions (Toro
et al. 2007). The landforms and deposits with various origins
support varied types of vegetation. The cryptogamic flora of
Byers Peninsula is remarkably rich, including 42 species
of mosses (Ochyra et al. 2008, ATCM 2011), similar to that
of South Bay, another important ice-free area on Livingston
Island (Sancho et al.1999).
Although lichen communities can be found throughout
Byers Peninsula, bryophyte vegetation is more developed
on the south coast (Lindsay 1971), and especially in
areas at low altitudes that benefit from nearby meltwater.
We analysed three terricolous cryptogamic communities
situated inland and on the southern beaches (Fig. 1)
which have different appearances and ecological affinities
(Fig. 2). Community A (‘‘moss carpet community’’)
comprises uniform moss carpets of highly hydrophilous
pleurocarpous mosses growing on wet coastal plains,
permanently bathed by melting snowpacks. Community B
(‘‘moss hummock community’’) corresponds to heterogeneous
moss assemblages dominated by large hummocks of
pleurocarpous mosses, irregularly patched with turfs and
cushions of acrocarpous mosses, developed on seepages
areas of raised beach terraces not permanently wetted.
Community C (‘‘lichen fellfield community’’) is an
example of a fellfield cryptogamic community dominated
by small foliose lichens accompanied by different mosses,
growing on seepage areas of exposed upland slopes that
dry out after the spring melt. Following the classification
by Smith (1996) and Ochyra et al. (2008) the three
communities can be related to three different types of
sub-formations within the non-vascular cryptogam tundra
formation. Community A corresponds to the bryophyte
carpet and mat sub-formation, Community B the tall moss
cushion (hummock) sub-formation, whereas Community C
is placed in the crustaceous and foliaceous lichen sub-
formation.
Fig. 2. Diagram of cryptogamic communities in South Beaches. Main image: large moss covered lowland area containing communities
A and B. Author: L.R. Pertierra. January 2010. Top left-hand image (1): highland containing Community C. Top right-hand image
(2): detail of fellfield lichen community (C) on exposed upland slopes. Bottom left-hand image (3): detail of a moss hummock
community (B) on a raised beach terrace. Bottom right-hand image (4): detail of a uniform moss carpet community (A) on
a coastal plane.
320 L.R. PERTIERRA et al.
Determination of baseline conditions
At the start of each experiment, before any trampling has
been initiated, the baseline conditions of each cryptogam
community were referred to as 'Level Zero' (0). In order to
conduct initial descriptions of the bryophyte and lichen
composition of each community, experimental plots of 6 m
2
that were representative of each community were selected.
Species composition was determined in the laboratory from
samples from the plots, following established procedures
(Sancho et al. 1999, Bednarek-Ochyra et al. 2000, Øvstedal
& Smith 2001, Putzke & Pereira 2001, Ochyra et al. 2008).
Specimens are stored in the MAUAM herbarium.
Edaphic parameters were determined in the laboratory
from triplicate core samples of each community. Soil organic
matter was quantified by the Walkley & Black wet oxidation
method (Nelson & Sommers 1982). Total nitrogen (N)
content was determined by the Kjeldahl method (Bremner
& Mulvaney 1982). Exchangeable potassium (K) was
determined by atomic absorption spectrometry using an
ammonium acetate extraction method (Thomas 1982). The
method of Olsen et al. (1954) was used to estimate available
phosphorus (P). Soil acidity (pH) was measured in water and
in 0.1 M potassium chloride (KCl) using a 1:2.5 soil/solution
ratio. Electrical conductivity was measured in a 1:5 soil:
water extract. General geomorphological information was
extracted from local cartography (Lo´pez-Martinez et al. 1996,
Navas et al. 2008).
Procedures for trampling experiments
Trampling was measured as the number of pedestrian
transits. For the purpose of standardization (Cole 1995a,
1995b), experiments were performed by a person 1.80 m
tall, weighing 85 kg and wearing rubber boots. Transects
followed the dimensions suggested by Cole & Bayfield
(1993). Dimensions of 6 m x 1 m were selected in order that
three random plots, each 25 cm x 25 cm, could be sampled
at each of five semi-quantitative stages. The five sampling
stages were defined by the resistance of the cryptogam
communities to trampling. The first sampling stage took
place when the first evidence of damage as a result of
trampling could be seen, or when 95% of the vegetation cover
remained intact. This stage was labelled as 'Level One' (1).
Trampling would continue and measurements were made at
subsequent levels of degradation including: 'Level Two' (2),
where c. 75% of the vegetation cover remained intact,
'Level Three' (3), where c. 50% of the vegetation cover
remained intact, 'Level Four' (4), where c. 25% of the
vegetation cover remained intact and 'Level Five' (5),
where less than 5% of the initial vegetation cover remained
intact. This approach was selected in order to fully cover
the dynamics of vegetation denudation. Since it represents
50% of vegetation denudation, 'Level Three' serves as an
indicator of resistance of the moss and lichen communities
that can be used for comparing with other studies. In the
remainder of this paper, we will refer to the various states
of the cryptogam communities by means of a code
combining the letter of the community (A-B-C) with the
level of degradation (0 to 5).
For the purpose of monitoring when the next sampling
stage was reached, the amount of vegetation cover was
estimated every time trampling intensity was doubled.
A grid of 25 squares was laid over a random plot
of 5 cm x 5 cm and photographically documented. The
percentage of area with complete loss of macroscopic
structure was estimated and used as a measure of the
loss of vegetation cover. Trampling intensity was increased
until total disruption of the crytogamic community was
reached.
At each sampling stage, physical and biological indicators
were measured in three random 25 cm x 25 cm sampling
plots. Soil resistance to penetration was used as an indicator
of the effective gradual impact on soil compaction (Tejedo
et al. 2005, 2009). Five measurements were taken at each
sampling stage on the soil of each cryptogam community
with a hand edaphic penetrometer. For total biomass and
water content, core samples were removed from the sampling
plots. In total, 54 circular cores were collected. Core
dimensions ( 7 cm diameter x 7 cm len gth) were s ufficient
to obtain approximately 200 g of wet samples. A core depth
of 7 cm was selected in order that all biomass could be
recovered after trampling. As a result, the measured biomass
and water content need to be considered at these conditions.
Soil fraction from additional samples was sieved in a 2 mm
mesh to measure soil moisture. Cores collected were frozen
at -208C in sealed bags until analysis.
Soil moisture, water content and total organic matter
were respectively quantified in triplicates through loss-on-
ignition technique with wet & dry weight calculation after
heating in porcelain crucibles in a muffle furnace. Soil
moisture (% soil weight) and water content (% sample weight)
Table I. Chemical properties and nutrient content of the soils from the terrestrial cryptogamic communities from Byers Peninsula.
Community nOrganic matter N C/N K
1
P pH Electric conductivity
(%) (%) (cmol
1
/Kg) (ppm) (1:2.5) (dS/m)
Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD Mean SD
A. Moss Carpet 3 1.70 1.21 0.14 0.08 11.53 2.87 0.66 0.19 1.22 0.23 6.33 0.26 0.05 0.00
B. Moss Hummock 3 1.60 0.62 0.15 0.06 12.24 0.97 0.61 0.08 1.27 0.99 6.06 0.16 0.07 0.04
C. Lichen Fellfield 3 2.53 0.90 0.23 0.07 10.98 1.58 0.35 0.03 0.43 0.18 6.99 0.98 0.22 0.06
TRAMPLING EFFECTS ON CRYPTOGAMIC COMMUNITIES 321
Fig. 3. Visual features. Visual status of experimental plots along trampling simulation respectively in A-B-C communities.
Author: L.R. Pertierra. January 2010.
322 L.R. PERTIERRA et al.
were measured after 24 hr at 1058C, while biomass
(mg carbon (C) cm
-2
soil) was measured after 4 hr at 4508C.
Results from soil resistance to penetration, water
content and total biomass were expressed with standard
deviations and represented in graphs. On these graphs the
model fit which best represented the observed trend was
also calculated with its coefficient of determination (r
2
).
Vegetation coverage loss trends were also represented.
It was estimated once per stage and thus no standard
deviations were obtained.
Experiments were conducted in the late summer on days
where there had been minimal precipitation on previous
days. Results on soil resistance to penetration and water
content are circumscribed within these conditions and
cannot be easily extrapolated to other studies. Nonetheless
all measurements were performed on the three communities
in parallel and they can therefore be compared.
Results
Floristic composition
Community A was made up of dense, uniform and
extensive moss carpets that developed on flat terrain,
and dominated by the hydrophilous pleurocarpous moss
Warnstorfia sarmentosa (Wahlenb.) Hedena¨s. Other
large mosses could be occasionally found, particularly
Sanionia georgicouncinata (Mu
¨ll. Hal.) Ochyra & Hedena¨s
and Polytrichastrum alpinum (Hedw.) G.L. Sm. The
community was heavily flooded, with a water content of
87% in core samples and a soil moisture content of 28%
(see Supplemental Table at http://dx.doi.org/10.1017/
S095410201200082X).
Community B comprised heterogeneous, moss dominated
vegetation growing on sandy pebble-rich substrate of raised
terraces, frequently adjacent to Community A but under
drier conditions. It was dominated by the pleurocarpous
Sanionia georgicouncinata and, to a lesser extent, by the
acrocarpous Polytrichastrum alpinum. Depending on
microtopographical conditions, which favoured greater or
lesser water supply, other species could be present, such
as Warnstorfia sarmentosa or Polytrichum juniperinum
Hedw. Intermixed with all these large mosses, many very
small species could appear in small proportions, and
we found Bartramia patens Brid., Pohlia wahlenbergii
(F. Weber & D. Mohr) A.L. Andrews, Andreaea regularis
Mu
¨ll.Hal., Brachythecium austrosalebrosum (Mu
¨ll.hal.)
Kindb., and the leafy liverwort Cephaloziella varians
(Gottsche) Steph. The Antarctic hairgrass Deschampsia
antarctica E. Desv. was also present in small patches.
Samples from this community had a water content of
53% and a soil moisture content of 19% (Supplemental
Table). The substrate was sandier, resulting in moderate
drainage, and bedrock was more evident and was
occasionally visible.
Community C was a cryptogam assemblage that
developed on upland terrains and was dominated by the
blackish foliose cyanolichen Leptogium puberulum Hue.
The pleurocarpous mosses Brachythecium subpilosum
(Hook. f. & Wilson) A. Jaeger and Sanionia uncinata
(Hedw.) Loeske were also abundant. Other mosses found in
lower proportions were Bartramia patens,Polytrichastrum
alpinum,Schistidium lewis-smithii Ochyra, and Pohlia
cruda (Hedw.) Lindb. This community grew on moraine
soils which were among the driest conditions included in
this study. Water content in the samples was c. 21% and
soil moisture was also around 20%.
Soil characteristics
Soil characteristics are shown in Table I. Organic matter (OM)
content was very poor for the moss dominated communities
A and B (mineralised soil), and was deficient in the
lichen fellfield Community C (soil mineral-organic).
Results are consistent with the C/N ratios, which indicates
that these nutrients do not act as constraints in the
humidification–mineralization process. Nitrogen content
is normal in Communities A and B, whereas it is
comparatively high in Community C which probably has
a higher mineral nitrogen ratio. Soils from all communities
have a low salt content, and hence low electrical
conductivity. All soils have very low values of phosphorus.
Levels of potassium in all soils can also be considered as low
but they lie within normal limits (Thomas et al. 2008).
Physical effects of trampling
The effects of trampling on cryptogamic vegetation are
influenced by several factors, such as hydrological
conditions, geography and topography. These factors may
influence the response of the plant communities to human
activity. Visual effects of trampling experiments were
Fig. 4. Physical features. Trampling intensity (passes) and
resistance to penetration (kilogrammes per square centimetre)
for trampling experiments at communities A, B and C.
TRAMPLING EFFECTS ON CRYPTOGAMIC COMMUNITIES 323
photographically documented (Fig. 3). In the case of
the moss carpet community (A), the first visible effects
were detected after the first 25 passes (A1). Macroscopic
destruction of the vegetation cover was detected after
300 passes (A5). The moss hummock community (B)
exhibited visible effects after 50 passes (B1) and reached
macroscopic destruction after 600 passes (B5). The lichen
fellfield community (C) exhibited visible effects after only
10 passes (C1) and reached macroscopic destruction after
only 160 passes (C5).
Soil characteristics differ between communities
(Table I). Data obtained on resistance to penetration are
shown in Fig. 4. Whereas initial values on soil compaction
were similar (c. 1kgcm
-2
) for communities A, B and C,
final values varied. Moss carpet community (A) soils’
compaction reached c. 300 passes without saturation when
the simulation ended due to the total loss of vegetation in
the community. Moss hummock community (B) has an
intermediate compaction on a slow rate up to 600 passes
when the experiment finished. Finally, lichen fellfield
community (C) has the fastest saturation at 160 passes with
the lowest maximum compaction of the three communities
at the end of the simulation.
The moss carpet community (A) was the richest in water
content. It contained 87% water content prior to the
experiment and at the end of the experiment, water content
fell to 67% (Fig. 5). All of the three communities showed
water loss as a result of trampling. Water content in the
moss hummock community (B) dropped from an initial
value of 55% to 26%. In the lichen fellfield community (C)
water content fell from 24% to 18%.
Biological effects of trampling
Trends of biological parameters are shown in Figs 6 & 7.
For all three communities, loss of vegetation coverage
as a consequence of increased trampling followed a
negative exponential model, although the variation rate was
different for each community (Fig. 6). The lichen fellfield
community (C) exhibited the fastest rate, whereas the moss
hummock community (B) showed the lowest of the three.
The visual details of the denudation process were quite
different for each community (Fig. 3). The moss carpet
community (A) showed an initial resistance. During the
first 10–15 passes, while footprints were visible, the
structure of the community was apparently unaffected. At
around 25 passes, first scars were observed and, as soon as
the cohesion was damaged, the fissures advanced rapidly.
Due to the high water content of this vegetation the
fragmented portions formed a muddy mass. At c. 300
passes the muddy mass had become sufficiently eroded to
reveal bare ground and allow puddles of water to form.
Seventy-eight passes were sufficient to result in loss of 50%
of the vegetation cover (Fig. 6).
Fig. 5. Hydrological features. Trampling intensity (passes) and
water content (percentage in weight) for trampling
experiments at communities A, B and C.
Fig. 6. Biological features (I). Trampling intensity (passes) and
vegetation coverage (percentage) for trampling experiments at
communities A, B and C.
Fig. 7. Biological features (II). Trampling intensity (passes) and
total biomass (milligrams per cm
2
soil) for trampling
experiments at communities A, B and C.
324 L.R. PERTIERRA et al.
The moss hummock community (B), growing on raised
beach terraces, was drier and easier to walk on. The
vegetation appeared to be firmer and exhibited a higher
resistance than that of Community A. To disturb the
cohesion required around 50 passes and scars were only
produced in the bigger tufts which were more exposed as
trampling continued and the vegetation was crushed instead
of turning into a muddy mass as in the case of Community A.
Loss of macroscopic moss coverage was not seen even up to
600 passes. One hundred and forty seven passes were needed
to cause a loss of 50% of the vegetation cover (Fig. 6).
Lichen fellfield community (C) was easily fractured with
less than 10 passes, as the dominant lichen had a crunchy
texture when dry. Total loss of plant cover was evident at
160 passes. Thirty-nine passes were sufficient to result in
50% loss of vegetation cover (Fig. 6).
Finally, total biomass per square centimetre of soil on
experimental plots was quantified to contrast with plant
coverage loss (Fig. 7). The moss carpet community (A)
contained the highest initial biomass of 629 mg C cm
-2
.
Approximately 74% of the initial biomass was removed
in the experimental process, leaving a final 165 mg C cm
-2
soil at the end of the trampling experiment. The moss
hummock community (B) had initially a 52% lower
biomass content than in A. Biomass content in B was at
328 mg C cm
-2
soil prior to trampling and was 121 mg C cm
-2
soil after trampling, corresponding to a 63% loss. The
lichen fellfield community (C) contained the lowest
biomass content. It was slightly lower than in B (60%)
and much lower than in A (31%). Biomass content in C
began at 200 mg C cm
-2
soil before trampling and ended at
72 mg C cm
-2
soil after trampling, corresponding to a 68%
biomass loss.
Discussion
Most of the mosses found in the samples from the
three communities are common on Livingston Island
(Sancho et al. 1999, Putzke & Pereira 2001, Ochyra et al.
2008), but two of them were reported for the first time for
the island: Pohlia wahlenbergii, already known from other
islands in the South Shetland Islands, and Brachythecium
subpilosum, a new report for the archipelago (Lara &
Pertierra 2012). Both species have small known Antarctic
populations (Ochyra et al. 2008). Liverworts are not
well represented in Antarctica, and the tiny Cephaloziella
varians is the most common and most widespread
liverwort in Antarctica (Newsham 2010), and is abundant
on Livingston Island (Sancho et al. 1999). The lichen
Leptogium puberulum and the vascular plant Deschampsia
antarctica one of the two phanerogams native to maritime
Antarctica are representative components of the local flora
(Lindsay 1971, Sancho et al. 1999). Communities that are
richer in biodiversity are likely to harbour rare species,
presumably with populations that are easily disturbed,
although further studies will be needed before it could be
determined if these populations are threatened.
Physical effects on soils
The pH ranges from slightly acidic (Communities A and B)
to neutral (Community C), which is consistent with data
obtained for this area by other authors (Navas et al. 2008).
These results correspond to oligotrophic sand soils. Organic
matter and electrical conductivity in Community C were
found to be slightly higher than in the other two sites,
but within the range of values quoted in previous studies
(Roser et al. 1994).
Soil resistance to penetration proves to be a good
indicator for assessing cumulative trampling effects in
soils. It is noteworthy that, after the plant layer is pierced,
the soil surface starts to act in the same way as bare
soils (Fig. 3). The increase in penetration with increased
trampling in Fig. 4 are similar to those found by Tejedo
et al. (2009) for bare soil, and these values could in
themselves be sufficient to disturb the existing edaphic
fauna. Soil characteristics such as texture also differed
among communities (Table I). Therefore the observed
differences can be also explained by the physical properties
of the soils of the different communities soils, such as bulk
density (Tejedo et al. 2009). Our results show that drier
areas with less dense vegetation were more sensitive to
disturbance from trampling. The presence of vegetation
prevented compaction by protecting the soil below.
In all three cryptogamic communities, water loss was
consistently proportional to trampling (Fig. 5). We found
that extreme conditions in water content affected negatively
the plant resistances. As a result the moss hummock
community (B) had in this case the highest resistance
capacities. The moss carpet community (A) had the highest
water content and hence exhibited the least resistance to
trampling. In the lichen fellfield community (C), we also
detected a diminished resistance that could be explained by
the extreme dryness of the vegetation due to the particular
environmental conditions that were present during the
period of our experiments. For this reason it can be argued
that resistance of the communities to trampling can be
severely affected by meteorological conditions. Differences
in resistance to penetration could be also linked to the
initial water content of the community.
In contrast, soil moisture did not change much between
communities nor along the transect (Supplemental Table),
indicating that it was not affected by the trampling process.
Long-term effects of trampling remain to be seen. Lower
water retention due both to compaction increase and
vegetation loss by trampling could lead to shifts in species
composition. This projection can be exemplified by the
results of Gremmen et al. (2003) who found significant
differences in species composition and soil moisture between
control plots and frequented paths on Marion Island.
TRAMPLING EFFECTS ON CRYPTOGAMIC COMMUNITIES 325
Biological disturbances
Damages to vegetation are perhaps the most evident
impacts from trampling (Fig. 3). The continuous and
spongy moss carpets, rich in biomass and with a high water
content, can absorb a small amount of disturbance. But,
as soon as their initial capacity to resist disturbance is
surpassed, the damage grows linearly with the amount of
disturbance. Our results are similar to those of de Leeuw’s
(1994) obtained from moss peat vegetation on Cuverville
Island, Danco Coast. In moss hummock communities
the damage is gradual and is tempered by the physical
characteristics of the community. Drier soils and strong
attachment to the substrate could prevent moss from direct
damage. These communities appear to be more resistant to
trampling, but we must ascertain whether, when certain
levels are surpassed, the damage becomes irreversible due
to extreme loss of water availability or a thinner soil layer.
Finally, lichen fellfield communities show a low degree of
vegetation resistance to trampling due to its extreme
dryness and the morphology of the dominant lichen with
the mixed mosses, which are weakly attached to the
substrate. Direct damage can be observed after a very small
amount of disturbance.
Amount of vegetation cover and visual changes served
as preliminary indicators for assessing degradation status
and resistance capacity of cryptogamic communities in
relation to different intensities of trampling (Figs 3 & 6).
However, vegetation is frequently patchy and circumstantial
disaggregation can be difficult to unequivocally distinguish
from the effects of human trampling. If new species are
found, it might be necessary to monitor small plots in order
to assess the effects of disturbance on plant richness. Thus,
this indicator relies on the existing reference conditions
(Fretwell et al. 2011). Alternatively the technique applied
by Gremmen et al. (2003) involved comparing species
composition along the path against composition on either
side of it. That technique overcomes the need for long time
series in sites without information on possible changes in
species composition when assessing already impacted areas.
With the present results, i.e. 50% cover loss within less
than 200 passes (Fig. 6), we consider all three communities as
extremely sensitive to human trampling (Cole 1995a, 1995b,
Farrell et al. 2001, 2002). Our results are similar to those of
the most sensitive species described by Cole & Bayfield
(1993), although their study was conducted on herbaceous
vascular plants. While our trampling experiments may be
indicating that these three cryptogamic communities in the
Antarctic Peninsula have low short-term resistance to
disturbance, it is possible that these communities possess
high recovery capacities since cryptogams are characterized
by their capacity for vegetative growth from fragmented units
(Smith 1993, Johansson & Thor 2008).
Total biomass decreased as the amount of disturbance
increased (Fig. 7). This was particularly evident in the case
of Community A (moss carpet community), where initial
biomass was the largest. Trampling fragmented the vegetation
which was scattered across the transect or washed away.
A large fraction of the fragmented vegetation (c.50%of
biomass) remained in the transect in a damaged condition
which can potentially act as a propagule bank. A key issue
here involves whether the erosion exceeds the recovery
capacity of the remaining biomass or the growth rate of new
propagules (Smith 1993, Johansson & Thor 2008).
Impact mitigation
Spatial strategies for minimizing impacts of trampling by
visitors in national parks are discussed in Leung & Marion
(1999) and, for the case of Antarctica, in Tejedo et al.
(in press). Here we detail some lessons learnt from the
present study for the minimization of damages to existing
communities. First, due to the extreme sensitivity of
cryptogamic communities, the best approach should always
be to avoid disturbing them. Alternative routes should be
considered. For instance, bare soils could be more resilient to
low traffic. For this approach Tejedo et al. (2009) contains
more detailed recommendations. Also, stream beds have
traditionally been considered as another alternative route;
however, there is little knowledge about the effects of human
traffic on freshwater ecosystems.
To avoid short-term irreversible damage to moss
carpet communities (A), access should be forbidden to
any large groups. In general, shore visits for tourist groups
are managed so that only 100 people are on shore at any
one time, with one guide for every 20 tourists (IAATO
2011). These numbers are sufficient to cause severe damage
which can easily spread over a large area. If the only
option is to cross over an area covered by moss carpet
communities, a sacrificial path that is precisely defined will
be a more preferable solution than letting the group spread
over a large area. Nonetheless this will not only inevitably
lead to the destruction of the moss community along the
path but will also turn the path into a muddy area. This is
due to the relatively high contents of water and biomass.
These muddy areas are likely to expand as people try to
avoid the existing muddy area by making detours, thereby
increasing the width of the path and creating even more
muddy areas, an idea expressed already in Gremmen et al.
(2003) and recently reported in Barrientos Island (Ecuador
& Spain 2012). Thus, from the perspective of the protection
of these cryptogam communities group leaders should
ensure that members of their group remain on the path. For
small groups of no more than 1–5 people passing through
this area once or twice, such as scientific expeditions,
our recommendation would be that they spread out, since
the trampling intensity is insufficient to produce direct
impact as long as the trampling pressure is not reproduced.
The impact can be easily spotted by the characteristic
indentations on the moss carpet (Fig. 3).
326 L.R. PERTIERRA et al.
In contrast, damage on moss hummock communities (B)
can become difficult to detect since the visual impact is less
identifiable than in A (Fig. 3). Large groups might not
observe any visible damage after their pass and may feel
free to walk there, but the damage is gradual and cumulative,
and visitors should be restricted to the sacrificial path in
order to avoid extended denudation processes. It should be
remembered that, as found in the samples studied, this
community contains a high diversity of bryophytes with rare
moss species.
The lichen fellfield community (C) shows a high degree
of sensitivity. Each pedestrian transit creates direct impact
and spreading is not an option, not even for small groups.
The impact on this community is not easily visualized due
to the low biomass and cryptic colours, with dominant
black and grey shades (Fig. 3). Elevated zones with
exposed lichen formation should be avoided by groups to
the maximum extent.
Conclusions
The three cryptogam communities studied are all highly
sensitive to trampling. Vegetation cover, soil characteristics,
water content and biomass were identified as relevant
aspects for the understanding of the denudation process.
High sensitivity was related to extreme hydration and
relatively large biomass in one community and to extreme
dryness and a weak attachment of plants to the substratum
in another community. The three communities behaved
differently in the trampling experiments but they all
exhibited low resistance of the vegetation to trampling.
Different strategies are suggested to minimize the impacts of
trampling; nonetheless the basic recommendation provided
by SCAR (2009) to directly avoid sensitive habitats would
be the first measure to apply to all these communities.
The capacity for a sustainable recovery from trampling
disturbances within the context of global change relies on
appropriate management systems addressing the relative
vulnerabilities of terrestrial ecosystems in Maritime
Antarctica (Reid 2007, Tin et al. 2009, Convey 2010).
Thus, a key issue for the future would then involve the study
and monitoring of the resilience of the plant communities.
Acknowledgements
This paper was contributed to by two projects:
LIMNOPOLAR and EVA-ANTARCTICA. They were
supported by the Spanish Government (POL2006-06635,
CGL2007-28761-E/ANT and CTM2009-06604-E).
Permission to work in the study area for the 2009–10
season was granted by the Spanish Polar Committee.
Logistical support was provided by the UTM (Marine
Technology Unit, CSIC) and the Spanish Navy. We thank
Dr Lars Wormer (University of Bremen, Germany) for his
‘trampling’’ field support. Thanks also to Dr Jero´ nimo
Lo´pez-Martinez from the Autonomous University of
Madrid, for the provision of Byers cartography. We also
thank two anonymous reviewers for their useful comments.
Finally, we have special thanks to Dr Tina Tin for her
frequent advice that greatly improved the paper.
Supplemental material
A supplemental table will be found at http://dx.doi.org/
10.1017/S095410201200082X
References
ASOC (ANTARCTIC AND SOUTHERN OCEAN COALITION). 2004. Environmental
reports of Fildes Peninsula, 1988–1997: benchmarks for environmental
management. Antarctic and Southern Ocean Coalition Report,
December 2004, 15 pp.
ATCM (ANTARCTIC TREATY CONSULTATIVE MEETING). 2011. Management
Plan for Antarctic Specially Protected Area No. 126 Byers Peninsula,
Livingston Island, South Shetland Islands. Measure 4,XXXIV Antarctic
Treaty Consultative Meeting, Buenos Aires, June 2011, 23 pp.
AYRES,E.,NKEM,J.N.,WALL, D.H., ADAMS, B.J., BARRETT, J.E., BROOS,E.J.,
PARSONS, A.N., POWERS,L.E.,SIMMONS,B.L.&VIRGINIA,R.A.2008.
Effects of human trampling on populations of soil fauna in the McMurdo
Dry Valleys, Antarctica. Conservation Biology,22, 1544–1551.
BASTMEIJER, C.J. & ROURA, R. 2004. Regulating Antarctic tourism and the
precautionary principle. American Journal of International Law,98,
763–781.
BEDNAREK-OCHYRA,H.,VA
´N
ˇA,J.,OCHYRA,R.&SMITH, R.I.L. 2000. The
liverwort flora of Antarctica. Cracow: Polish Academy of Sciences, 236 pp.
BERTRAM, E. 2007. Antartic ship-borne tourism: an expanding industry. In
SNYDER, J.M. & STONEHOUSE, B., ed. Prospects for polar tourism.
Trowbridge: CABI, 149–169.
BEYER,L.&BO
¨LTER, M. 2002. Geoecology of Antarctic ice free coastal
landscapes. Berlin: Springer, 463 pp.
BREMNER, J.M. & MULVANEY, J.L. 1982. 1982. Nitrogen - total. In PAGE,
A.L., MILLER R.H. & KEENEY, D.R., eds. Methods of soil analysis, part 2.
Madison, WI: American Society of Agronomy, 595–624.
COLE, D.N. 1995a. Experimental trampling of vegetation. I. Relationship
between trampling intensity and vegetation response. Journal of Applied
Ecology,32, 203–214.
COLE, D.N. 1995b. Experimental trampling of vegetation. II. Predictors of
resistance and resilience. Journal of Applied Ecology,32, 215–224.
COLE, D.N. & BAYFIELD, N.G. 1993. Recreational trampling of vegetation:
standard experimental procedures. Biological Conservation,63, 209–215.
CONVEY, P. 2010. Terrestrial biodiversity in Antarctica: recent advances
and future challenges. Polar Science,4, 135–147.
DELEEUW, C. 1994. Tourism in Antarctica and its impact on vegetation.
PhD thesis, Groningen: Arctic Centre, University of Groningen, 38 pp.
[Unpublished].
ECUADOR &SPAIN. 2012. Revision of the visitor guidelines for visited sites:
Barrientos Island (Aitcho Is.). Working Paper 59, XXXV Antarctic
Treaty Consultative Meeting, Hobart, 10–20 June 2012.
FARRELL, T.A. & MARION, L.J. 2001. Identifying and assessing ecotourism
visitor impacts at selected protected areas in Costa Rica and Belize.
Environmental Conservation,28, 215–225.
FARRELL, T.A. & MARION, L.J. 2002. Trail impacts and trail impact
management related to ecotourism visitation at Torres del Paine
National Park, Chile. Journal of the Canadian Association for Leisure
Studies,26, 31–59.
FRENOT, Y., CHOWN, S.L., WHINAM, J., SELKIRK, P., CONVEY, P., SKOTNICKI,
M. & BERGSTROM, D. 2005. Biological invasions in the Antarctic: extent,
impacts and implications. Biological Reviews,80, 45–72.
TRAMPLING EFFECTS ON CRYPTOGAMIC COMMUNITIES 327
FRETWELL, P.T., CONVEY, P., FLEMING, H.A., PEAT, H.J. & HUGHES, K.A.
2011. Detecting and mapping vegetation distribution on the Antarctic
Peninsula from remote sensing data. Polar Biology,34, 273–281.
GREMMEN, N.J.M., SMITH, V.R. & VAN TORENGEN, O.F.R. 2003. Impact of
trampling on the vegetation of subantarctic Marion Island. Arctic,
Antarctic, and Alpine Research,35, 442–446.
HUGHES, K.A. & CONVEY, P. 2010. The protection of Antarctic terrestrial
ecosystems from inter- and intra-continental transfer of non-indigenous
species by human activities: a review of current systems and practices.
Global Environmental Change,20, 96–112.
HUGHES, K.A., FRETWELL, P., RAE, J., HOLMES,K.&FLEMING, A. 2011.
Untouched Antarctica: mapping a finite and diminishing environmental
resource. Antarctic Science,23, 537–548.
IAATO (INTERNATIONAL ASSOCIATION OF ANTARCTIC TOUR-OPERATORS).
2011. Guidelines for visitors to the Antarctic. http://iaato.org/es/
visitor-guidelines accessed 30 June 2012.
JOHANSSON,P.&THOR, G. 2008. Lichen species density and abundance
over ten years in permanent plots in inland Drowning Maud Land,
Antarctica. Antarctic Science,20, 115–121.
LARA,F.&PERTIERRA, L.R. 2012. Brachythecium subpilosum (Hook. f. &
Wilson) 645 A. Jaeger. In ELLIS, L., ed. New national and regional
Bryophyte records, No. 32. Journal of Bryology.
LEUNG,Y.&MARION, J.L. 1999. Spatial strategies for managing visitor
impacts in National Parks. Journal of Park and Recreation
Administration,17, 20–38.
LINDSAY, D.C. 1971. Vegetation of the South Shetland Islands. British
Antarctic Survey Bulletin, No. 25, 59–83.
LO
´PEZ-MARTI
´NEZ, J., MARTI
´NEZ DE PISO
´N, E., SERRANO,E.&ARCHE,A.
1996. Geomorphological map of Byers Peninsula, Livingston Island.
BAS GEOMAP series, sheet 5-a, 1:25 000, with supplementary text.
Cambridge: British Antarctic Survey, 65 pp.
LYNCH, H.J., CROSBIE, K., FAGAN, W.F. & NAVEEN, R. 2010. Spatial patterns
of tour ship traffic in the Antarctic Peninsula region. Antarctic Science,
22, 123–130.
MARION, J.L. & COLE, D.N. 1996. Spatial and temporal variation in soil and
vegetation impacts on campsites. Ecological Applications,6, 520–530.
MARION, J.L. & LEUNG, Y. 2001. Trail resource impacts and an examination
of alternative assessment techniques. Journal of Park and Recreation
Administration,19, 17–37.
NAVAS, A., LO
´PEZ-MARTI
´NEZ, J., CASAS, J., MACHI
´N, J., DURA
´N, J.J.,
SERRANO, E., CUCHI,F.&MINK, S. 2008. Soil characteristics on varying
lithological substrates in the South Shetland Islands, maritime
Antarctica. Geoderma,144, 123–139.
NELSON, D.W. & SOMMERS, L.E. 1982. Total carbon, organic carbon and
organic matter. In PAGE, A.L., MILLER R.H. & KEENEY, D.R., eds.
Methods of soil analysis, part 2. Madison, WI: American Society of
Agronomy, 539–579.
NEWSHAM, K.K. 2010. The biology and ecology of the liverwort
Cephaloziella varians in Antarctica. Antarctic Science,22, 131–143.
OCHYRA, R., SMITH, R.I.L. & BEDNAREK-OCHYRA, H. 2008. The illustrated
moss flora of Antarctica. Cambridge: Cambridge University Press,
685 pp.
OLECH, M. 1996. Human impact on terrestrial ecosystems in West Antarctica.
NIPR Symposium on Polar Biology Proceedings, No. 9, 299–306.
OLSEN, R.S., COLE, V.C., WATANABE, F.S. & DEAN, L.A. 1954. Estimation
of available phosphorus in soils by extraction with sodium bicarbonate.
Washington, DC: USDA Circular 939.
ØVSTEDAL, D.O. & SMITH, R.I.L. 2001. Lichens of Antarctica and South
Georgia: a guide to their identification and ecology. Cambridge:
Cambridge University Press, 424 pp.
PUTZKE,J.&PEREIRA,A.B.2001.The Antarctic mosses, with special
reference to the South Shetland Islands. Ulbra: Editora Da Ulbra, 196 pp.
QUESADA, A., CAMACHO, A., ROCHERA,C.&VELA
´ZQUEZ, D. 2009. Byers
Peninsula: a reference site for coastal, terrestrial and limnetic ecosystem
studies in maritime Antarctica. Polar Science,3, 181–187.
REID, K. 2007. Monitoring and management in the Antarctic making the
link between science and policy. Antarctic Science,19, 267–270.
ROSER, D.J., SEPPELT, R.D. & NORDSTROM, O. 1994. Soluble carbohydrate
and organic acid content of soils and associate microbiota from the
Windmill Islands, Budd Coast, Antarctica. Antarctic Science,6, 53–59.
SANCHO, L.G., SCHULZ, F., SCHOETER,B.&KAPPEN, L. 1999. Bryophyte and
lichen flora of South Bay, Livingston Island: South Shetland Islands,
Antarctica. Nova Hedwigia,68, 301–337.
SCAR (SCIENTIFIC COMMITEE ON ANTARCTIC RESEARCH). 2009. Environmental
code of conduct for terrestrial scientific field research in Antarctica.
www.scar.org/researchgroups/lifesciences/Code_of_Conduct_Jan09.pdf
accessed 21 December 2011.
SCOTT, J.J. & KIRKPATRICK, J.B. 1994. Effects of human trampling on the
sub-Antarctic vegetation of Macquarie Island. Polar Record,30, 207–220.
SMITH, R.I.L. 1988. Destruction of Antarctic terrestrial ecosystems by a
rapidly increasing fur seal population. Biological Conservation,45, 55–72.
SMITH, R.I.L. 1993. The role of bryophyte propagule banks in a primary
succession: case study of an Antarctic fellfield soil. In MILES,J.&
WALTON, D.W.H., eds. Primary succession on land. Oxford: Blackwell
Scientific Publications, 55–78.
SMITH, R.I.L. 1994. Vascular plants as bioindicators of regional warming in
Antarctica. Oecologia,99, 322–328.
SMITH, R.I.L. 1996. Terrestrial and freshwater biotic components of the
western Antarctic Peninsula. Antarctic Research Series,70, 15–59.
SMITH,R.I.L.&RICHARDSON, M. 2011. Fuegian plants in Antarctica: natural
or anthropogenically assisted immigrants? Biological Invasions,13,15.
TEJEDO, P., JUSTEL, A., RICO, E., BENAYAS,J.&QUESADA, A. 2005.
Measuring impacts on soils by human activity in an Antarctic Special
Protected Area. Terra Antarctica Reports,12, 57–62.
TEJEDO, P., JUSTEL, A., BENAYAS, J., RICO, E., CONVEY,P.&QUESADA,A.
2009. Soil trampling in an Antarctic Specially Protected Area: tools to
assess levels of human impact. Antarctic Science,21, 229–236.
TEJEDO,P.,PERTIERRA,L.,BENAYAS,J.,CONVEY,P.,JUSTEL,A.&QUESADA,A.
In press. Trampling on maritime Antarctica: can soil ecosystems be
effectively protected through existing codes of conduct? Polar Research.
THOMAS, D.N., FOGG, G.E., CONVEY, P., FRITSEN, C.H., GILI, J.M.,
GRADINGER, R., LAYBOURN-PARRY, J., REID,K.&WALTON, D.W.H.
2008. The biology of Polar Regions, 2nd ed. Oxford: Oxford University
Press, 394 pp.
THOMAS, G.W. 1982. Exchangeable cations. In PAGE, A.L., MILLER, R.H. &
KEENEY, D.R., eds. Methods of soil analysis, part 2. Madison, WI:
American Society of Agronomy, 154–165.
THOR, G. 1997. Establishment of permanent plots with lichens and mosses
for monitoring local human impact on environment in Heimefrontfjella
and Vestfjella, Dronning Maud Land, Antarctica. Antarctic Record,41,
652–672.
TIN,T.,FLEMING,Z.L.,HUGHES, K.A., AINLEY, D.G., CONVEY,P.,MORENO,C.A.,
PFEIFFER, S., SCOTT,J.&SNAPE, I. 2009. Impacts of local human
activities on the Antarctic environment. Antarctic Science,21, 3–33.
TORO, M., CAMACHO, A., ROCHERA, C., RICO, E., BAN
˜O
´N, M., FERNA
´NDEZ-
VALIENTE, E., MARCO, E., JUSTEL, A., VINCENT, W.F., AVENDAN
˜O, M.C.,
ARIOSA,Y.&QUESADA, A. 2007. Limnological characteristics of the
freshwater ecosystems of Byers Peninsula, Livingston Island, in
maritime Antarctica. Polar Biology,30, 635–649.
TURNER, J., COLWELL, S.R., MARSHALL, G.J., LACHLAN-COPE, T.A.,
CARLETON, A.M., JONES, P.D., LAGUN, V., REID, P.A. & IAGOVKINA,S.
2005. Antarctic climate change during the last 50 years. International
Journal of Climatology,25, 279–294.
VAUGHAN, D.G., MARSHALL, G.L., CONNOLLEY, W.L., PARKINSON, C.,
MULVANEY, R., HODGSON, D.A., KING, J.C., PUDSEY, C.J. & TURNER,J.
2003. Recent rapid regional climate warming on the Antarctic
Peninsula. Climatic Change,60, 243–274.
WEST, M.H. & MAXTED, A.P. 2000. An assessment of tundra degradation
resulting from the presence of a field camp in Kongsfjorden, Svalbard.
Polar Record,36, 203–210.
328 L.R. PERTIERRA et al.
... Although numerous studies have documented vegetation responses to trampling disturbance, research on trampling impacts at different organizational levels is often limited [36]. Most of the previous studies on vegetation disturbance by trampling have focused on the impacts on communities and vascular plants [14,21,24,[37][38][39][40], but the impacts of trampling on lichens and bryophytes are less well documented [25,41,42]. ...
... In terms of species richness [43,44], biomass [45][46][47] and, especially, nutrient cycling [46,[48][49][50], lichens and mosses play a role, especially, at higher latitudes and altitudes [43,44]. Lichens and bryophytes are significant parts of ecosystem functioning in areas that are considered to be particularly vulnerable to human disturbance [41]. Knowledge concerning the trampling of lichens and mosses in a recreational alpine area is important. ...
... However, trampling's effects on the species richness and diversity of lichens and bryophytes have seldom been examined [42,75,76], and the impacts on the abundance and cover vary. The abundance of both bryophytes and lichens may be reduced [7,41] or increased [20,42], or there may be a delayed reduction in the lichen and bryophyte abundance [20]. The importance of lichens and mosses in alpine ecosystems is understudied and, therefore, further studies on the effects of trampling are needed [74]. ...
Article
Full-text available
Due to the destruction of alpine ecosystems by extreme human trampling, some alpine areas are closed to tourists. After years of regeneration, a tendency toward reopening these areas for tourism is envisaged. Although numerous studies have documented vegetative responses to trampling disturbance, research that thoroughly examines the trampling impacts on the vegetation at different organizational levels is often limited. Most of the previous studies on the human disturbance of vegetation focused on the impacts on vascular plants, while the impacts on lichens or mosses are less well-documented. To understand how regenerated communities respond to further trampling disturbance, we repeated the experimental research on short-term trampling after 14 years in three high-altitude communities in the Tatras in northern Slovakia. According to Cole and Bayfield’s protocol, we evaluated the resistance of communities trampled in 2008 and 2022, with a focus on groups of lichens and mosses and their individual species. This research brings new knowledge regarding the different behaviors of regenerated vegetation, especially lichens and mosses, to trampling disturbance. The results show that human trampling in alpine communities has a large negative impact and, therefore, management plans should discourage off-trail hiking and limit recreational activities in sensitive or reopened alpine areas.
... Trampling reduces the cover, height, and species density of ground vegetation (Liddle, 1975a;Jägerbrand & Alatalo, 2015). Several studies have shown that there is a delay between trampling impact and vegetation decline (Forbes et al., 2004;Pertierra et al., 2013). ...
... The responses of vegetation to trampling have been reported to be affected by trampling intensity (Cole, 1987;Cole, 1995a), frequency (Cole & Monz, 2002), distribution (Gallet et al., 2004), season (Gallet & Rozé, 2002), weather (Gallet & Roze, 2001), habitat (Liddle, 1975b), species (Gallet et al., 2004), Raunkiaer life-form (perennating bud position) and growthform (Cole, 1995b), and soil type (Talbot et al., 2003). Most previous studies of human disturbance of vegetation have focused on the impacts on vascular plants (Bernhardt-Römermann et al., 2011;Pescott & Stewart, 2014), while the impacts on plant community composition, bryophytes or lichens are less well documented (Crisfield et al., 2012;Pertierra et al., 2013). ...
Article
Full-text available
Trampling of vegetation as a result of recreation can adversely affect natural habitats, leading to loss of vegetation and degradation of plant communities. Many studies indicated that intrinsic properties of plant communities appear to be the most important factors determining the response of vegetation to trampling disturbance. Specifically, the dominant life-form of a plant community accounts for more variation in the resistance of communities to trampling than the intensity of the trampling experienced, suggesting that simple assessments based on this trait could guide decisions on access to natural sites. We verify these claims in the Belianske Tatry National Nature Reserve in Slovakia, which has been closed since 1978 due to destruction by mass tourism, with the exception of one trail made accessible since 1993. In researching the resistance of communities according to dominant life forms we adjusted the number of passes according to the minimum (75 tourists) and maximum (225 tourists) daily visitation during the tourist season. The studied communities occur in close proximity to the trails on the saddles through which the open trail passes. Available evidence from our studies suggests that vegetation dominated by hemicryptophytes is more resistant to trampling and recovers from trampling to a greater extent than vegetation dominated by other life forms. Therefore, we selected three alpine communities dominated by hemicryptophytes. In the Juncetum trifidi community, they almost completely dominate, they are mainly composed of grasses. Although they dominate the Junco trifidi-Callunetum vulgaris community, the species, Calluna vulgaris has been added to the woody chamephytes, and thus the woody Chamaephytes achieve a higher cover than in the Juncetum trifidi community. Although in the community Seslerietum tatrae biscutelletosum laevigatae hemicryptophytes dominate, it consists of several plant life forms and its grasses reach greater heights than in previous communities. We found that it is not possible to estimate the resilience of communities to trampling by dominant life forms. Life forms within one community react very similarly, but this statement cannot be generalized globally for all communities. At the same time, we found that if we damage the native community, which subsequently regenerates, the life forms of the community behave differently when damaged repeatedly. More detailed research is needed worldwide, which would point out patterns of behaviour of alpine plant vegetation to trampling.
... Its negative impacts might be propagated to higher levels, such as weakening ecosystem stability and functioning due to species loss [17,18]. Even very small numbers of visitors can cause ecological changes [19,20]. ...
... Although numerous studies have documented vegetation responses to trampling disturbance, research that thoroughly examines trampling impacts on vegetation at dif-ferent organizational levels (e.g., species, population, and community levels) is often limited [21]. Most previous studies of human disturbance on vegetation have focused on the impacts on vascular plants [12,14,[22][23][24][25][26][27], while the impacts on plant community composition, bryophytes or lichens are less well documented [13,20,28]. However, bryophytes and lichens at high latitudes play a significant role in terms of species richness [29,30]. ...
Article
Full-text available
Over the past decades, outdoor recreation in mountains has become progressively more important and as a result human induced potential damage has increased. Alpine communities are particularly susceptible to human recreational activities, such as tourist trampling. Although there are a number of studies that explicitly assess the effects of trampling on alpine communities, they do not reflect on terrains with a rich topography and the presence of more communities in very small areas. In this study, effects of short-term trampling on some alpine communities in the Tatras, the highest mountains of the Carpathians, were studied experimentally. Vulnerability to disturbance was compared among plant communities in terms of resistance and resilience, which are based on cover measurements. With proximity to trampling intensity, we found a significant decrease in plant cover and abundance of deciduous shrubs, lichens, and mosses. These results demonstrate that human trampling in alpine communities has major negative impacts on lichen and moss abundance and species richness. A short-term trampling experiment required several years of community regeneration. Therefore, management plans should discourage hiking activity off paths and restrict recreational activities.
... Trampling is one of the most significant disturbances in this context. Trampling can change the substrate's physiochemical properties (such as the bulk density and penetration resistance [Tejedo et al., 2005;O'Neill et al., 2015]), biology (mostly through direct plant cover decrease [Cajiao et al., 2020]), and nutrient availability (Pertierra et al., 2013). Most intense trampling and disturbance occur in the vicinity of research stations or field camps and at key tourist sites. ...
Article
Full-text available
Antarctica plays a central role in regulating global climatic and oceanographic patterns and is an integral part of global climate change discussions. The functioning of Antarctica's terrestrial ecosystems is dominated by poikilohydric cryptogams such as lichens, bryophytes, eukaryotic algae, and cyanobacteria and there are only two native species of vascular plants. Antarctica's vegetation is highly adapted to the region's extreme conditions but, at the same time, it is potentially highly susceptible to climatic fluctuations. Biological responses to shifts in temperature, water availability, wind patterns, snow, and ice cover are complex, taxa‐specific and act on different temporal and spatial scales. In maritime Antarctica, where warming and mass loss of outlet glaciers have been mainly observed, the vegetation is expected to show increases in productivity, abundance, and cover. In continental Antarctica, observational and experimental evidence is still sparse, but it is pointing toward even drier and harsher conditions for survival. We need more information on what the observed and predicted changes in Antarctic vegetation are for different regions and ecosystems. This will inform us how environmental change and human impact will shape the future of these ecosystems, and whether the speed and magnitude of change have habitat‐specific effects and implications. Antarctica's unique ecosystems are changing and in this review, we describe the current situation, tools to measure, and evaluate change and how change is likely to look in the future. This article is categorized under: Climate, Ecology, and Conservation > Observed Ecological Changes Assessing Impacts of Climate Change > Evaluating Future Impacts of Climate Change Climate, Ecology, and Conservation > Modeling Species and Community Interactions Assessing Impacts of Climate Change > Observed Impacts of Climate Change
... Various studies have warned of the potential negative impacts of increasing scientific and tourism activity, further facilitated by synergy with rapid regional climate change, with vegetation being particularly sensitive to destruction (Tin et al. 2009, Chown et al. 2012, Tejedo et al. 2012, Convey & Peck 2019. This damage derives from various mechanisms, including direct trampling (Pertierra et al. 2013), the overall scale of the footprint of human activity (Pertierra et al. 2017) and the areal extent of the built environment directly incorporated within stations (Brooks et al. 2019). Furthermore, low rates of energy flow and nutrient cycling, associated with the slow development of moss communities, exacerbate the sensitivity of these ecosystems to disturbance (Walker et al. 1997), leading to extended recovery times and highlighting the need for conservation not only within protected area boundaries but throughout the entire bay. ...
Article
Full-text available
We set out to document the diversity and distribution of bryophytes in Admiralty Bay and thereby enable the identification of patterns in local diversity and their possible drivers. Combining data extracted from different sources and recent collections, we documented the presence of 63 species. Similarity analyses of moss species diversity in relation to underlying geology and ornithogenic influence identified an identical cophenetic correlation coefficient of 0.744 for both factors. The Sørensen index was < 0.6, indicating that the groups share < 60% of the species recorded. The data showed that the selected filters (ornithogenic soils, non-ornithogenic soils and different geological extracts) did not underlie consistent species groupings, and we conclude that other environmental and topographical factors are likely to be responsible for shaping the moss community structure in Admiralty Bay. To enable effective management of Antarctic Specially Managed Area (ASMA) No. 1 and Antarctic Specially Protected Area (ASPA) No. 128, robust assessments of the local ecosystem and biodiversity are necessary to assist in the decision-making processes mandated under the Antarctic Treaty System, one of whose founding principles is the preservation of the Antarctic ecosystem.
... While many articles have cited the adverse effects of trampling as a potential impact of tourism (e.g., Chen and Blume, 1997;Tin et al., 2009), only very few empirical studies have been developed to date. Much research on this topic corresponds to experimental studies not specifically designed to evaluate the consequences of tourism, but of researchers doing fieldwork (e.g., Pertierra et al., 2013). Actual data on trampling and footpath development by Antarctic tourists are rare (e.g., Tejedo et al., 2016). ...
Article
Full-text available
Human activities in Antarctica were increasing before the COVID-19 pandemic, and tourism was not an exception. The growth and diversification of Antarctic tourism over the last few decades have been extensively studied. However, environmental impacts associated with this activity have received less attention despite an increasing body of scholarship examining environmental issues related to Antarctic tourism. Aside from raising important research questions, the potential negative effects of tourist visits in Antarctica are also an issue discussed by Antarctic Treaty Consultative Parties. This study presents the results of a meta-analysis of scholarly publications that synthesizes and updates our current knowledge of environmental impacts resulting from Antarctic tourism. A first publication database containing 233 records that focussed on this topic was compiled and subjected to a general bibliometric and content analysis. Further, an in-depth content analysis was performed on a subset of 75 records, which were focussed on showing specific research on Antarctic tourism impacts. The main topic, methods, management proposals, and research gaps highlighted by the respective authors of these 75 publications were assessed. The range of research topics addressed, the methods used-including the application of established research designs from the field of environmental impact assessment-, and the conclusions reached by the study authors are discussed. Interestingly, almost one third of the studies did not detect a direct relationship between tourism and significant negative effects on the environment. Cumulative impacts of tourism have received little attention, and long-term and comprehensive monitoring programs have been discussed only rarely, leading us to assume that such long-term programs are scarce. More importantly, connections between research and policy or management do not always exist. This analysis highlights the need for a comprehensive strategy to investigate and monitor the environmental impacts of tourism in Antarctica. A first specific research and monitoring programme to stimulate a debate among members of the Antarctic scientific and policy communities is proposed, with the ultimate goal of advancing the regulation and management of Antarctic tourism collaboratively.
... Es importante destacar también que B. orbiculatifolium es una especie poco conocida, y probablemente no ha sido recolectada en todos los sitios donde eventualmente habitaría dentro de su amplio rango geográfico . Además, al igual que muchas otras especies de musgos, es probable que sea altamente vulnerable al pisoteo humano (Pertierra et al. 2013), por lo que conocer acerca de su presencia fuera de las zonas ZAEP, y alejada de las zonas de principal actividad geotérmica en la Isla Decepción, permitiría obtener nueva información de esta especie, lo que favorecería su conservación. En este sentido, el resto de las especies detectadas en el transecto (y en la isla en general) no quedan ajenas al peligro de la actividad humana: la Isla Decepción es una de las más visitadas por turistas. ...
Article
Full-text available
Con el objetivo de determinar la influencia de las pingüineras sobre la diversidad de la vegetación en la Isla Decepción, se estudió la composición de briófitas de un transecto de aproximadamente 2 km entre el Lago Irízar y la pingüinera (Pygoscelis antarcticus) de Punta La Descubierta. Fueron detectados un total de 39 carpetas de vegetación formadas principalmente por briófitos, distribuidas en tres sectores principales, aledaño al Lago Irízar, en Collado Vapor y en Punta La Descubierta. Los briófitos registrados corresponden a 15 especies de musgos y sólo 2 hepáticas, con 11 familias representadas. Se detectó que dos musgos, Sanionia uncinata y Politrychastrum alpinum, con 31 y 9 registros, dominaban las carpetas, con mayor abundancia y frecuencia. Además, se encontró un nuevo registro para la isla del musgo Bryum orbiculatifolium, el cual crece directamente asociado a la pingüinera. Además, se encontró que hay 5 especies de musgos comunes a los tres sectores, aunque otras 5 especies crecen solo en el sector de la pingüinera, diferenciándose esta comunidad de las otras dos. No se detectaron plantas vasculares en todo el sitio de estudio, por lo que se discute la posibilidad de que estos sitios se encuentran en estados de colonización temprana y donde su biota está marcada por la presencia de musgos pioneros que crecen alrededor de las pingüineras, influenciadas probablemente por el aporte de nutrientes del guano depositado.
... Previous studies have found a negative effect of trampling on lichens in alpine ecosystems and maritime Antarctica ( Czortek et al., 2018a ;Grabherr, 1982 ;Jägerbrand and Alatalo, 2015 ;Pertierra et al., 2013 ). Similarly, in the present study three of the eight most common lichen species included in the analysis showed a significant decrease with proximity to the trail. ...
Article
Full-text available
Alpine ecosystems are under increasing pressure due to tourism and recreational activities. When leaving designated trails as is frequently observed, visitors can cause unintentional damage to vegetation. This study investigated the effect of human trampling on the dominant species of vascular plants, bryophytes and lichens along an infrequently used hiking trail in an alpine ecosystem in sub-arctic Sweden. The hypothesis tested was that proximity to the trail (as an effect of more people leaving the trail for a short distance compared to a longer distance) causes a decrease in species with low resistance to trampling. With a greater decrease in taller forbs and shrubs than in graminoids and prostrate plants, a greater decrease in lichen than in bryophyte species, and a change in vegetation composition. The results showed that proximity to the trail did not cause a decrease in the majority of dominant species, with none of the eight most dominant vascular plants showing any significant effects of proximity to the trail. One bryophyte species (Dicranum elongatum) among the six most commonly found decreased with proximity to the trail. Three lichen species (Cladonia arbuscula, Cladonia uncinalis, Ochrolechia frigida) among the eight most common species decreased with proximity to the trail. There was no evidence that taller species decreased with proximity to the trail, although the deciduous shrub Betula nana showed a tendency for a decrease. Proximity to the trail caused a greater decrease in lichen species than in bryophyte species. Multivariate analyses showed that distance from trail and transect direction had significant effects on overall vegetation composition. The level of low-intensity trampling recorded indicates that current numbers of hikers at the site can be sustained for longer periods with minimum impact on vascular plant species, but to get a more general understanding of the impact of low-intensity trampling data from additional sites are needed.
Article
Full-text available
The Antarctic Specially Protected Areas (ASPAs) are zones with restricted access to protect outstanding environmental, scientific, historic, aesthetic, or wilderness values adopted inside the Antarctic Treaty System. Meanwhile, in southern Patagonia, conservation initiatives are implemented by the state of Chile and private entities. However, both are considered unrepresentative. Our work evaluates the representativeness of the in situ conservation through a genetic approach of the moss Sanionia uncinata (Hedw.) Loeske among protected and neighboring free access areas in Maritime Antarctica and southern Patagonia. We discuss observed presence with both current and reconstructed past potential niche distributions (11 and 6 ka BP) in the Fildes Peninsula on King George Island. Results showed occurrence of several spatially genetic subpopulations distributed inside and among ASPA and free access sites. Some free access sites showed a higher amount of polymorphism compared with ASPA, having ancestry in populations developed in those places since 6 ka BP. The different spatial and temporal hierarchies in the analysis suggest that places for conservation of this species in Maritime Antarctica are not well-represented, and that some free access areas should be considered. This work represents a powerful multidisciplinary approach and a great challenge for decision-makers to improve the management plans and the sustainable development in Antarctica.
Article
Full-text available
There has been an ongoing increase in tourist visits to the Antarctic since 2010. These visits primarily concentrate on a small number of sites, increasing the possible environmental impact. One of the tourism hotspots is the central Argentine Islands in Wilhelm Archipelago. These islands, being one of the top 20 most visited Antarctic sites, consist of Galindez Island, Winter Island, and Skua Island. They are known for wildlife, rich vegetation (old moss banks, rich bryophyte and lichen communities, Antarctic pearlwort Colobanthus quitensis and hairgrass Deschampsia antarctica populations), spectacular views. They include one of the oldest Antarctic research stations: the Ukrainian Antarctic Akademik Vernadsky station. Previously no measures have been developed to minimize the impact of tourism on this region. Thus, the Visitor Site Guidelines (VSG) approach and the numerous studies in the region were used to determine the central values of this site and to identify those key features that can be opened for tourists. In addition to the most frequently mentioned values, such as seabirds and mammals, we considered it necessary to mention the vegetation. We assessed threats to these values, distinguishing known and potential impacts. We have also analyzed and developed landing requirements for the studied area, including the most critical requirement to be considered, namely the number of visitors. We think that the maximum number of visitors should be 36 at any time and 270 per day, not counting passengers of yachts. This is the first time that the Visitor Site Guidelines were modified to limit the number of yachts visiting the site to three yachts per day. To reduce the tourist load at the station itself and at the same time to concentrate tourists in the studied region, we proposed two tourist trails: one for Galindez Island, the other — the existing trail for Winter Island. The prepared draft of Visitor Site Guidelines is given in Appendix 2.
Article
Full-text available
One hundred and ten lichen and fifty bryophyte species are reported from the vicinity of the Spanish Antarctic research station Juan Carlos I. (BAE; Livingston Island, South Shetland Islands). The study site consists of an ice-free area of around 3 km2 on the southern coast of South Bay. Considering its small extent this area has a remarkably large biodiversity. The present catalogue is the largest so far reported for any single Antarctic locality. For some lichen genera such as Caloplaca, Cladonia and Umbilicaria, this part of Livingston Island probably has the highest species diversity of any site in the Antarctic region. We found very different phytogeographic patterns for lichens and bryophytes. Whereas 21% of the lichen species are endemic, only 10% of the bryophyte species have an exclusively Antarctic distribution. In contrast, bryophytes with a Southern Hemisphere distribution contribute 31% to the bryophyte flora, while only 10% of the studied lichens have this pattern of distribution. Ecology, distribution and taxonomic status of some of the recorded species are also briefly discussed.
Article
Full-text available
Protected area visitation is an important component of ecotourism, and as such, must be sustainable. However, protected area visitation may degrade natural resources, particularly in areas of concentrated visitor activities like trails and recreation sites. This is an important concern in ecotourism destinations such as Belize and Costa Rica, because they actively promote ecotourism and emphasize the pristine qualities of their natural resources. Research on visitor impacts to protected areas has many potential applications in protected area management, though it has not been widely applied in Central and South America. This study targeted this deficiency through manager interviews and evaluations of alternative impact assessment procedures at eight protected areas in Belize and Costa Rica. Impact assessment procedures included qualitative condition class systems, ratings systems, and measurement-based systems applied to trails and recreation sites. The resulting data characterize manager perceptions of impact problems, document trail and recreation site impacts, and provide examples of inexpensive, efficient and effective rapid impact assessment procedures. Interview subjects reported a variety of impacts affecting trails, recreation sites, wildlife, water, attraction features and other resources. Standardized assessment procedures were developed and applied to record trail and recreation site impacts. Impacts affecting the study areas included trail proliferation, erosion and widening, muddiness on trails, vegetation cover loss, soil and root exposure, and tree damage on recreation sites. The findings also illustrate the types of assessment data yielded by several alternative methods and demonstrate their utility to protected area managers. The need for additional rapid assessment procedures for wildlife, water, attraction feature and other resource impacts was also identified.
Book
Research in Antarctica in the past two decades has fundamentally changed our perceptions of the southern continent. This volume describes typical terrestrial environments of the maritime and continental Antarctic. Life and chemical processes are restricted to small ranges of ambient temperature, availability of water and nutrients. This is reflected not only in life processes, but also in those of weathering and pedogenesis. The volume focuses on interactions between plants, animals and soils. It includes aspects of climate change, soil development and biology, as well as above- and below-ground results of interdisciplinary research projects combining data from botany, zoology, microbiology, pedology, and soil ecology.
Article
Bryophyte colonists develop from sexual and asexual propagules deposited over a long period from both local and distant provenances. Some may rapidly establish new plants; others remain dormant indefinitely on or beneath the surface of the substratum. The viable component of these diaspores, the soil propagule bank, constitutes a reservoir of potential colonists. An environmental stimulus or suite of stimuli may activate the dormant viable propagules into developing as new plants. Before this, microbial modification of the soil surface is usually required to bind and stabilize soil particles and provide a nutrient base. Laboratory and field experiments on maritime Antarctic soils are used to illustrate aspects of the bryophyte propagule bank. The importance of ice fields as a sink for spores and vegetative propagules is stressed. Their release in meltwater onto terrestrial habitats near the ice margins is of particular importance in colonziation of newly exposed substrata. Possible efects of global warming, especially in polar regions, on these propagule banks, on the rate of colonization and on the species composition of the developing communities is considered. -from Author
Chapter
Total carbon (C) in soils is the sum of both organic and inorganic C. Organic C is present in the soil organic matter fraction, whereas inorganic C is largely found in carbonate minerals. The wet combustion analysis of soils by chromic acid digestion has long been a standard method for determining total C, giving results in good agreement with dry combustion. Methods for total C are basic for many of the procedures used to determine organic C in soils. In contrast to noncalcareous soils, inorganic C must be removed from calcareous or limed soils before the analysis if wet or dry combustion techniques are used to directly measure the organic C present. The organic matter content of soil may be indirectly estimated through multiplication of the organic C concentration by the ratio of organic matter to organic C commonly found in soils.