impact of the black-capped marmot (marmota camtschatica bungei) on floristic diversity of arctic...

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Impact of the Black-Capped Marmot (Marmota camtschatica bungei) on Floristic Diversity ofArctic Tundra in Northern SiberiaAuthor(s): Youri Semenov, Raymond Ramousse, Michel Le Berre and Youri TutukarovSource: Arctic, Antarctic, and Alpine Research, Vol. 33, No. 2 (May, 2001), pp. 204-210Published by: INSTAAR, University of ColoradoStable URL: http://www.jstor.org/stable/1552221 .

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Arctic, Antarctic, and Alpine Research, Vol. 33, No. 2, 2001, pp. 204-210

Impact of the Black-capped Marmot (Marmota camtschatica bungei) on Floristic Diversity of Arctic Tundra in Northern Siberia

Youri Semenov, Raymond Ramousse, * and Michel Le Berre Equipe de Socioecologie et Conservation, Laboratoire de Biom6trie et Biologie Evolutive UMR CNRS 5558, Universite Claude Bernard Lyon 1, 43 bd du 11 Novembre 1918 bat. 403, 69622 Villeurbanne Cedex, France. * Author for correspondence. ramousse @biomserv.univ-lyon 1 .fr

Youri Tutukarov Faculty of Biology, Yakutsk State University, 58 Belinsky Prospect, 677891 Yakutsk, Russia.

Introduction

In any ecosystem, dynamic relations between plants and animals influence vegetation in many different ways. Selective feed- ing can affect plant populations directly by reducing growth (Ar- cher et al., 1987) and survival of preferred plant species and there- by indirectly benefit other less preferred species (Archer and De- tling, 1984; Pacala and Crawley, 1992; McKendrick et al., 1997). Herbivores may also affect the availability of resources that limit plant development. Animals can alter soil physically and chemi- cally by burrow digging, trampling, and depositing urine or feces. Studies have shown that burrowing animals have significantly affected plant communities (Marmota bobac and M. baibacina

[Zimina and Zlotin, 1980]; M. monax [Swihart, 1991]; M. olympus [Del Moral, 1984]; Cynomys ludovicianus [Archer et al., 1987]; Geomys bursarius [Reichman and Smith, 1985; Inouye et al., 1987]; Thomomys bottae [Koide et al., 1987; Hobbs et al., 1988]; Taxidea taxus [Platt, 1975]). There is reason to believe that animals have similarly affected plant communities in the Arctic.

Arctic tundra is characterized by severe environmental conditions, including low temperatures and permafrost. Tundra eco- systems are generally limited by low availability of nutrients, often nitrogen; productivity increases when nutrients are added (Shaver and Chapin, 1980, 1986). The typical flora includes lichens, bryophytes, shrubs, and herbs. Some plant species are listed as endangered (Labutin et al., 1985). Mammalian species in particular appear to have substantial effects on soil nutrients and vegetation in arctic tundra: arctic ground squirrel (Spermo- philus parryii) mounds (McKendrick et al., 1980; Mallory and Heffernan, 1987) and caribou (Rangifer tarandus) carrion (McKendrick et al., 1980) significantly alter the floristics of the

plant community, with increasing importance of graminoids and decreasing importance of lichens and shrubs.

In some areas of the arctic tundra of Northern Siberia, black- capped marmots (Marmota camtschatica bungei Kastchenko 1901) are found between 100 and 1500 m above sea level (a.s.l.). Two

Abstract The impact of black-capped marmots on arctic tundra vegetation was examined by descriptive and quantitative methods in three marmot home ranges. Vegetation in the home range core area (main burrows) differed from the peripheral zone

(secondary burrows, paths, scratching areas) or from marmot-free tundra area. In main burrow plots species richness, diversity, and equitability were low. In the same places graminoid abundance were increased, whereas dominance of shrubs and presence of cryptogams (bryophytes and lichens) were declined. Some forbs were more often found around marmot main burrows. Some of these are rare and listed as protected species in Siberian Arctic tundra. This suggests that through activities such as burrowing, trampling, and excretion black-capped marmots

modify microrelief and soil properties, which influence the floristic structure and

composition of the arctic tundra.

endangered populations (Kondakovskaya and Ioujno-Yakoutskaia) are listed in the Red Book of the Sakha Republic (Yakutia, Russian Federation; Revin et al., 1987). These are medium-sized, ground- dwelling animals, which as adults average 2-4 kg (Kapitonov, 1978); they are well adapted to the harsh arctic environment. They are active during the polar day and hibernate from mid-September to May. Marmots are sedentary animals living in family groups on home ranges which they often occupy for very long periods, some- times centuries (Zimina and Zlotin, 1980). Home ranges extend on 10-15 ha including a core area and a peripheral zone (Kapitonov, 1978; pers. observ.). The core area is centered on a main burrow system with large mounds and latrines on top of the tundra surface. The main burrow consists of several meters of galleries and one or two rooms at a depth of 0.25 to 0.6 m, where the family group hibernates and where the female gives birth. The peripheral zone is characterized by several paths on the tundra surface, secondary burrows, shelters, and scratching places (Kapitonov, 1978).

Kapitonov (1960, 1978) emphasized visible changes in vegetation growth and greenness always associated with marmot core areas, strongly contrasting with the usual brown aspect of the tundra. Sofronov (1997) suggested that floristic composition differed between marmot-active and marmot-free areas. Quan- titative analysis and direct evidence for these conclusions, however, are not available.

The black-capped marmots develop extensive burrow and path systems, which disturb soil and vegetation. The objective of this study was to test the hypothesis that black-capped marmots have a substantial impact on certain characteristics of arctic flora. We compared floristics and plant cover between marmot- active areas and marmot-free areas. Results are discussed in relation to vegetation-animal interactions in the arctic ecosystem.

Methods STUDY AREA

This work was conducted in the Lena Delta Nature Reserve near the Arctic Ocean coast (71?57'N, 127?17'E, 250 m a.s.l.),

204 / ARCTIC, ANTARCTIC, AND ALPINE RESEARCH



in Sakha Republic (Yakutia, Russian Federation). In this region the mean temperature varies from 34.0?C below zero in winter to 8.9?C in summer (Spravochnik po klimatu SSSR, 1967). The permafrost layer reaches 400 to 600 m in depth (Kudryavtsev et al., 1978). The summer melting depth varies from 0.1 to 1.0 m depending on several factors including plant distribution, soil moisture, slope aspect, and topography (Karavaeva, 1969). In- vestigations took place on shrub tundra with high abundance of Dryas punctata and Cassiope tetragona (Labutin et al., 1985). During July and August 1998, three black-capped marmot home ranges located on southwest-facing rocky hills were chosen as three sample sites: HR1, HR2, and HR3.

SAMPLING METHODS

Two perpendicular transects, each 100 m long, were centered on the main burrow of the marmot home ranges (HR1, HR2, and HR3). One-square-meter plots were established every 5 m on both sides of the transects for a total of 80 plots per marmot home range. Characteristic activity marks of marmots were recorded: burrows, scratching areas (5 to 10 cm depth, 10 cm diameter), temporary shelters (one entrance only), paths, and outside latrines (30 cm depth, 15-40 cm diameter). Three plot categories were defined based on evidence of marmot activity: (P1) heavily impacted plots (core area of marmot home range with main burrows and outside latrines); (P2) lightly impacted plots (peripheral zone of marmot home range including secondary burrows, path or scratching area); (P3) marmot-free tundra plots (tundra area without marmot marks). Vegetation (lichens, bryophytes, and vascular plant species) was sampled in each plot by estimating number of floristic species (species richness), height, and the cover of each plant species. Median species diversity and equitability were calculated for each plot and each home range using the Shannon-Weaver diversity index (H; log base 10) and the equitability index (J; log base 10; Begon et al., 1990).

STATISTICAL ANALYSES

Because data failed to meet normal statistical assumptions, nonparametric statistics were used with a significance level of 0.05. Frequency of vegetation species in the three plot categories (P1, P2, and P3) was tested using Fisher's exact probability (Sie- gel, 1956). Kruskal-Wallis one-way analysis of variance and multiple comparisons of medians (smallest significant difference; Sprent, 1992) were used to test for significant differences between medians in floristic species richness, percent cover, average height, species diversity (H), and species equitability (J) between the three plot categories.

Percent cover was ranked among six classes: 0, 0-<5, 5- <15, 15-<25, 25-<50, 50-<100. The resulting matrices (plots X species) of cover rankings were analyzed by correspondence analysis (COA) using ADE-4 software (Thioulouse et al., 1997) to describe the vegetation composition with respect to marmot activity.

For analyses of percent cover and average height of plant species in relation to activity of marmots, the data for the species of the three home ranges were regrouped to increase the sample sizes.

Results GENERAL VEGETATION IN THE THREE HOME RANGES

In the three home ranges, general vegetation was primarily dominated by Dryas punctata and secondarily by Cassiope te-

TABLE 1

Mean percent cover of the five main species in each home range

HR1 HR2 HR3

N 80 80 80

SHRUBS

Dryas puncata 27.0 19.4 21.6

Cassiope tetragona 10.0 12.1 12.2 Salix glauca 7.4

CRYPTOGAMS Aulacomnium turgi-

dum 7.7 6.7 4.4

Hylocomium splendens 9.4 7.4 Cetraria juniperina 4.9

Stereocaulon alpinum 9.1 4.2

HR: home range; N: total number of plots.

tragona (Table 1). Fifty-one vascular plant, four bryophyte, and ten lichen species were found on the three home ranges. The same species of bryophytes and lichens occurred in the three home ranges. Only 31 of the 51 vascular plant species were common to the three home ranges. Three of these are listed as endangered in Siberian arctic tundra: Potentilla gelida, Rhodiola rosea, and Sausserea schanginiana (Labutin et al., 1985). Ten

plant species were present in only two home ranges and 10 were present in only one home range.

DOMINANT VEGETATION SPECIES IN EACH PLOT CATEGORY

The floristic description shows the same organization in the three marmot home ranges (Table 2). Lightly impacted and marmot-free tundra plots (P2 and P3) are characterized by a great abundance of shrubs (Dryas puncata and Cassiope tetragona) and a presence of cryptogams. Heavily impacted plots (P1) are characterized by a great abundance of graminoids (Poa arctica) and critical reducing of cryptogams.

VEGETATION SPECIES RICHNESS, SHANNON-WEAVER DIVERSITY (H) AND EQUITABILITY (J)

Analyses of species richness, diversity and equitability of vegetation in relation to activity of marmots revealed significant differences among the plot categories (Table 3). The number of vascular plant, bryophyte, and lichen species in P1 were significantly lower than in P2 and P3 plots. In the plots P1 corresponding to core area of black-capped marmot home ranges, bryophytes, and lichens were very rare.

In any of the home ranges, the Shannon-Weaver diversity index among vascular plants and cryptogams in P1 plots was significantly lower than in P2 and P3 plots (Table 3). The same trends were detected when comparing Shannon-Weaver equitability index among vascular plants and cryptogams.

FLORISTIC COMPOSITION IN RELATION TO ACTIVITY OF MARMOTS

The floristic community associated with heavily impacted plots (P1) differed from that beyond them in lightly impacted and marmot-free tundra plots (P2 and P3). For the three home ranges, the distribution of sample scores defined by the two first axes of COA indicated that Fl axis was for the clustering of P1 plots (Fig. la, 2a, 3a). This was confirmed by their important

Y. SEMENOV ET AL. / 205



TABLE 2

Mean percent cover of dominant species and cryptogams in three plots categories

HR1 HR2 HR3

P1 P2 P3 P1 P2 P3 P1 P2 P3

N 10 16 54 12 14 54 12 4 64

DOMINANT SPECIES

Poa arctica 24.6 0.2 0.4 24.7 1.5 0.4 21.3 0.1 0.4

Cassiope tetragona 0.1 4.1 10.0 0.2 12.6 14.6 0.7 23.0 13.7

Dryas puncata 5.3 43.1 24.0 4.7 31.6 19.5 19.8 19.0 21.7

CRYPTOGAMS

Bryophytes Aulacomnium turgidum 0.0 2.4 7.7 0.8 6.0 8.2 0.6 7.9 4.9

Dicranum acutifolium 0.1 0.9 2.1 0.2 0.7 0.9 0.4 3.1 2.2

Hylocomium splendens 0.0 0.8 1.1 0.0 7.6 11.8 0.0 2.6 9.1

Pohlia cruda 0.0 0.1 1.4 0.0 0.8 0.7 0.0 0.4 0.9 Lichens

Alectoria ochroleuca 0.0 0.1 0.3 0.0 0.3 0.3 0.0 0.1 0.6 Cetraria chrysantha 0.0 0.1 0.5 0.0 0.0 0.1 0.0 0.1 0.5 Cetraria juniperina 0.0 0.7 4.9 0.0 3.6 2.6 0.0 2.8 4.8 Cetraria laevigata 0.0 1.2 2.0 0.0 0.9 1.0 0.0 1.8 2.7 Cladonia chlorophaea 0.0 0.1 0.1 0.0 0.1 0.1 0.0 0.3 0.1

Cladonia sylvatica 0.0 0.8 1.8 0.0 0.1 0.3 0.0 0.3 1.5

Dactylina arctica 0.0 0.3 1.0 0.0 0.7 0.6 0.0 0.5 0.8

Peltigera aphthosa 0.0 0.2 0.2 0.1 0.6 0.2 0.0 0.1 0.2

Stereocaulon alpinum 0.0 2.6 9.1 0.1 1.8 3.1 0.0 1.3 5.1

Thamnolia vermicularis 0.0 1.0 2.8 0.0 1.4 1.2 0.0 0.4 2.2

HR: home range; N: total number of plots; P1: heavily impacted plots (main burrows and latrines); P2: lightly impacted plots (secondary burrows and paths); P3: marmot-free tundra plots.

absolute and relative contributions to Fl. For every home range, in factorial plans Fl and F2 the points corresponding to P2 and P3 plots are grouped near the center of gravity of the graph.

In the second graph for each home range (Fig. lb, 2b, 3b) floristic points were projected. The limited dispersion of these

points indicated a high floristic homogeneity within P2 and P3

plots. Conversely, the great dispersal of P1 data indicated im-

portant floristic heterogeneity among heavily impacted plots. A common effect was observed in the home ranges (Fig.

1, 2, 3). On F1, P1 data were different from P2 and P3 data clustered near the origin of the Fl and F2 axes. This may have resulted in differences in species composition among the plots. For some species, which for a great part were common to the three home ranges, the points were projected in the vicinity of the P1 plots (Fig. 1, 2, 3). This suggested a particular abundance

or even the exclusive presence of these vegetation species in the P1 plots.

VEGETATION SPECIES FREQUENCY

The number of plots containing species associated with P1

plots (Fig. 1, 2, 3), indicated their frequency in core areas (P1) was significantly higher than P2 or P3 for any of the three home

ranges (Fisher's exact probability test, Table 4). Comparisons of

species frequency between P2 and P3 plots revealed significant differences only for Poa arctica and Polygonum laxmannii (Ta- ble 4). Species more often found only around main burrows and outside latrines of marmots were these vascular plants: Alope- curus alpinus, Delfinium chamissonis, Myosotis suaveolens, Poa

arctica, Polygonum laxmannii, Potentilla gelida, Rhodiola ro-

TABLE 3

Comparisons of species richness, Shannon-Weaver diversity (H) and equitability (J) among three plot categories of each home range

HR1 HR2 HR3

P1 P2 P3 KW P1 P2 P3 KW P1 P2 P3 KW

N 10 16 54 12 14 54 12 4 64

MRV 6.5b 9 10 <0.01 5a,b 8.5 9 <0.001 5a,b 8.5 10 <0.001 MRB Oab 2 3 <0.001 0a,b 3 2 <0.001 Oa.b 4 3 <0.001 MRL 0a,b 5 6 <0.001 Oab 6 4 <0.001 Oab 6 6 <0.001 MH 0.35ab 0.52C 0.9 <0.001 0.35a,b 0.7 0.77 <0.001 0.39a,b 0.81 0.84 <0.001 MJ 0.44b 0.45c 0.71 <0.001 0.49 0.59 0.65 ns 0.59b 0.64 0.66 <0.001

HR, N, and plot descriptions as in Table 2. MRV: median richness of vascular plants; MRB: median richness of bryophytes; MRL: median richness of lichens; MH: median Shannon-Weaver diversity index; MJ: median Shannon-Weaver equitability index; KW: Kruskal-Wallis one-way analysis of variance; multiple comparisons: astatistically significant difference between P1 and P2; bstatistically significant difference between P1 and P3; cstatistically significant difference between P2 and P3; ns: not statistically significant; significance level 0.05.




FIGURE 1. Home range 1. Factorial plans F] and F2(COA) obtained from species abundance data. Plot coordin- dates (a) are expressed as closed cirles (heavily impacted plots regrouped by ellipse 1); open cirles (medium and lightly impacted plots regrouped by ellipse 2 and 3). Floristic coor- dinates (b) regrouped in relation to plot categories. Eigen- values diagram (c) shows the data structure. Species associated with PI plots; dech-Delfi- nium chamissonis; mysu-Myo- sotis suaveolens; poar-Poa arctica; plla-Polygonum laxmannii; ptge-Potentilla gelida; rhro-Rhodiola rosea; tach-Ta- raxacum chamissonis.

sea, and Taraxacum chamissonis. Most of the species associated with P1 plots were common to the three home ranges.

PERCENT COVER AND AVERAGE PLANT HEIGHT

Median cover percent and median average height of Poa arctica associated with P1 plots were significantly higher than in P2 and P3 plots (Table 5). We conclude that Poa arctica biomass increased in the core area of black-capped marmots. This results in light green patches of vegetation that conspicu- ously distinguishes these locations from the general tundra during summer.

Discussion

Concepts of coexisting species in ecological communities are based on partitioning and utilization of common resources, whereas many species have been implicated in adaptations to particular forms of competition, stress or disturbance (Grime, 1974). Competition may be defined as the attempt by neighbor- ing plants to utilize the same units of light, water, mineral nu-

trients or space (Grime, 1973). Stress is the result of environmental impact induced by factors such as drought and changes in availability of mineral nutrients (Grime, 1973). Disturbance is brought about by phenomena such as grazing, mowing, and trampling, which by defoliation or other forms of vegetation damage tend to give resistant plants a competitive advantage (Grime, 1973; Platt, 1975; Archer and Detling, 1984). Stress and disturbance together comprise those phenomena which affect the resolution of competition (Grime, 1974).

Core areas of black-capped marmot home ranges are associated with the most intensive marmot activities such as burrowing, trampling, hibernation, and reproduction (Kapitonov, 1978; Perrin, 1993). They induce damage for local vegetation and disturbance of microrelief and edaphic condition: changing soil moisture retention and aeration, which influence mineralization or decomposition rate (Zimina and Zlotin, 1980; Inouye et al., 1987; Koide et al., 1987). During the activity period, marmots fertilize the soil around the main burrow entrances by excretion, or removal of nest litter and cadavers of animals died in hibernation (Kapitonov, 1978; Zimina and Zlotin, 1980; Bibikov, 1989). Soil fertilization brings changes in vegetation aspect:

a b

FIGURE 2. Home range 2. Descriptions as for Figure 1. Species associated with P1 plots: alal-Alopecurus; dech- Delfinium chamissonis; mysu- Myosotis suaveolens; poar-Poa arctica; ptge-Potentilla gelida; rhro-Rhodolia rosea; tach-Ta- raxacum chamissonis.




FIGURE 3. Home range 3. Descriptions as for Figure 1. Species associated with P1 plots: dech-Delfinium chamissonis; mysu-Myosotis suaveolens; poar-Poa arctica; ptge- Potentilla gelida.

brighter colors, rapid growth rates, and increase of plant biomass and growing time (Shubin et al., 1978; Laundr6, 1998). These local disturbances increase environmental heterogeneity by opening space and altering the microhabitat that may then be

exploited by different species (Platt, 1975). Colonizing species like Poa arctica occupy the free space and become dominant. The smallest vascular plants, dominant shrubs (Dryas punctata, Cassiopa tetragona), bryophytes and lichens are easily over-

grown and shaded by Poa arctica, with a decline of species richness and diversity as a consequence. Similar development of Poa arctica has been observed around reindeer breeders' camps or other places where tundra plants are heavily grazed and soil is trampled and highly fertilized (Arkticheskaya flora SSSR, 1964). Experimental fertilization studies in arctic and subarctic tundra reported an increase in the abundance of graminoids and reduced the abundance of cryptogams (McKendrick et al., 1980; Jonasson, 1992; Parson et al., 1995). Other vascular plant species (Alopecurus alpinus, Delphinium chamissonis, Myosotis suav-

eolens, Polygonum laxmannii, Potentilla gelida, Rhodiola rosea, Taraxacum chamissonis) then find adequate environment and es- tablish near latrines and around main burrow entrances. For ex-

ample, Potentilla gelida exploits disturbed sites (Arkticheskaya

flora SSSR, 1964). Rhodiola rosea, a succulent plant, exhibits

rapid growth rates early in the growing season when water is more available (Arkticheskaya flora SSSR, 1984). Delphinium chamissonis and Myosotis suaveolens are associated with a high concentration of nitrogenous organic matter. In Arctic tundra, these plants are found around nests of prey bird and near arctic fox burrows, and are considered nitrogen indicator species (Ark-

ticheskaya flora SSSR, 1971, 1980; Labutin et al., 1985). Some of these plant species linked to main burrows of black-capped marmots are rare and protected in the Siberian Arctic tundra, such as Potentilla gelida and Rhodiola rosea (Labutin et al., 1985).

A similar effect has been described for the impact of the arctic ground squirrel (Spermophilus parryii) on tundra vegetation in North America (McKendrick et al., 1980; Mallory and Heffeman, 1987). Where ground squirrels are numerous, abundance of lichens and shrubs decreases and cover of graminoids and some dicotyledon species increase.

The peripheral areas of marmot home ranges, with paths and secondary burrows, are associated with occasional presence of marmots. Consequently, these represented a moderate inten-

sity of disturbance. Our analyses of vegetation revealed no sig-

TABLE 4

Numbers of plots containing plant species in common with P1 plots (obtained by COA)

HR1 HR2 HR3

P1 P2 P3 F-t P1 P2 P3 F-t P1 P2 P3 F-t

N 10 16 54 12 14 54 12 4 64

Alopecurus alpinus 9 0 1 a,b

Delfinium chamis- 4 1 0 b 3 1 1 b 2 1 0 b

sonis

Myosotis suaveolens 5 1 0 a,b 6 1 1 a,b 2 0 0 b Poa arctica 10 6 5 a,b,c 11 7 12 a,b,c 11 1 17 a,b Polygonum laxmannii 9 2 0 a,b,c Potentilla gelida 6 0 0 a,b 3 2 2 b 3 0 0 b Rhodiola rosea 4 2 1 b 5 2 5 b 0 0 3 ns Taraxacum chamissonis 2 1 0 b 3 2 1 b

HR, N, and plot descriptions as in Table 2. F-t: Fisher exact probability test; a: statistically significant difference between P1 and P2; b: statistically significant difference between P1 and P3; c: statistically significant difference between P2 and P3; ns: not statistically significant; significance level 0.05.




TABLE 5

Percent Cover and Average Height comparison for Poa arctica

HR1, HR2, HR3

P1 P2 P3 KW

N 33 14 34

Median Percent Cover 20a,b 0.5 0.5 <0.001

Median Average Height 17a,b 15 14 <0.001

HR, and plot descriptions as in Table 2. N: total number of plots containing Poa arctica; KW: Kruskal-Wallis one-way analysis of variance; multiple com-

parisons: astatistically significant difference between P1 and P2; bstatistically

significant difference between P1 and P3; significance level 0.05.

nificant difference between these habitats and marmot-free tundra.

The change observed in floristic distribution in the vicinity of black-capped marmot main burrows suggests a favorable effect for the marmots. In such locations, they easily find plant material for stuffing burrows. The amount of hay litter trans- ported into each main burrow varies from 9 to 12 kg (Kapitonov, 1978). On the other hand, lengthening the plant life cycle is a guarantee of fresh green food at the end of summer when the whole tundra flora has become dry (Kapitonov, 1978; pers. observ.).

Results of this study show that vegetation in the core area of black-capped marmot home range differed qualitatively and quantitatively from the peripheral zone and from marmot-free tundra. Through their activities such as burrowing, trampling, excretion, and removal of nest litter and cadavers of animals that died in hibernation, black-capped marmots probably modify microrelief and soil properties, which influence the floristic structure and composition of the arctic tundra. However, long- term experimental manipulations of animals, soil, and plants will be necessary to understand the actual mechanisms of the impacts and plant species succession in a long time scale.

Acknowledgments We would like to thank the Lena Delta Nature Reserve for

providing accommodation and Prof. R. Grantham and the ref- erees for their corrections of the English manuscript. This work was supported by INTAS 941428 and by French Environment Agency 95-087.

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Ms submitted May 2000




impact of the black-capped marmot (marmota camtschatica bungei) on floristic diversity of arctic...

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