Kamchatka is a peninsula of approximately the same size as the Scandinavian Peninsula. Although far away from each other on the northern hemisphere, both areas have northern connections to the mainland and a rather similar fauna and flora. However, one main difference is that Kamchatka is highly influenced by volcanic activity. Another difference is that the past vegetation in the Beringia area has been shaped by a somewhat different herbivore fauna (e.g. mega-herbivores) than has the vegetation in Scandinavia. These similarities and dissimilarities offer unique possibilities for comparative studies between Kamchatka and Scandinavia on plant – herbivore systems. Further, the fact that the two areas have rather similar natural resources but are managed within different societal systems offers many interesting comparisons.

The aims

During the Beringia 2005 expedition our main task was to perform the fieldwork in Kamchatka. Later, studies with the same methodological approach will be performed in Scandinavia and also, if possible, in Alaska.

Our aims were to:

• Estimate the abundance of different herbivores in terrestrial systems
• Estimate the impact of various functional groups of herbivores on their environment
• Collect information on plant morphological traits and to collect samples for chemical analyses
• Gather information on various land uses, especially those related to wildlife.

The sites

We studied the terrestrial habitats of four main sites:

1. Utka River (53°14,91’N, 156°50,61’E; approx. 170 m a.s.l., 15–19 July 2005). The area is undulating, with height differences of approx. 30 m and with bow-shaped rises, seemingly an old river landscape. The vegetation is characterized by comparatively dry mires dominated by Myrica tomentosa and without Sphagna. On higher ground are extensive Betula ermanii forests, seemingly untouched by forestry. Utka River is fringed by riparian forest of Alnus hirsuta and Salix udensis and of tall herb (1.5–2.0 m) meadows with Filipendula kamchatica. 
2. Ichinskaya Sopka Volcano (55°46,08’N, 157°45,00’E, approx. 1 225 m a.s.l., 20–27 July). The landscape is dominated by up to 3 607 m high volcanoes with glaciers and snow-covered peaks, separated by wide U-shaped valleys with braided rivers. The whole area is above the tree line and the vegetation is dominated by alpine dwarf-shrub heaths with dwarf willows, Ericaceae spp., including two small Rhododendron species, and lichens. In the valley bottoms on gravel and boulder-fields one can find approx. 1 m tall herbaceous grass-dominated vegetation including Leymus interior and Chamaenerion latifolium.
3. Karaginsky Island (58°57,84’N, 164°13,56’E, approx. 205 m a.s.l., 31 July–6 August). The interior of Karaginsky Island is mountainous, with peaks of >900 m and frequent snow beds, intersected by usually fairly narrow river valleys, occasionally widening to open meadows. Below approx. 150 m Betula ermanii forests can be found and on higher altitudes there are extensive impenetrable thickets of Alnus fruticosa or Pinus pumila intermixed with small areas of dry heaths with dwarf-shrubs or wet fens.
4. Vilyuchinskaya Sopka Volcano (52°39,059’N, 158°10,378’E, approx. 535 m a.s.l., 9–11 August). The area is situated >500 m above sea level and the highest volcanoes have snow-covered peaks, but landforms are relatively soft. The vegetation is dominated by alpine heath, with Ericaceae spp., dwarf willows, Betula nana and many herbs, e.g. Oxytropis sp. On lower slopes there are extensive thickets of Alnus fruticosa and a little Pinus pumila, and along rivers there are Salix udensis and tall herbs like Cirsium kamchaticum.

The herbivores

We focused on the herbivores feeding on the leaves/needles of woody plants, as well as on forbs and grasses. The main effort was directed to mammals (table 1) and herbivorous insects (mainly sawflies, beetles and butterflies). Information on mammals was collected by systematic observations along transects, collections with traps and to some extent observations on mountain slopes with spotting scopes. Site 2 had the highest species richness of mammalian herbivores while the other three sites had lower richness. When possible we collected insects using sweep nets and pitfall traps.

The impact of herbivores

We estimated the impact of mammalian herbivores using line transects. Our field protocol was designed to be analysed with distance sampling. Along the transects we recorded mammalian herbivory and other ecological “disturbances” by mammals.

Distance sampling does not require a certain shape or travel route. However for logistic reasons we aimed at collecting data along the sides of a triangle, terrain permitting, with equal sides of 1 km. In total we logged two triangles, or approx. 6 km, at each of the four main sites, plus an extra 1 km-transect in riverine vegetation at site 1. When walking along the legs we recorded all signs of browsing and grazing, as well as tracks, trails, diggings, scrapings and faeces. Two persons performed the survey. The first person used the GPS to follow the pre-determined route. He furthermore surveyed the ground for faeces and tracks. The second person surveyed the ground for herbivory and all other impacts. The equilateral distance from the walked line to each observation was measured. The route and all observations, together with borders of major vegetation types were given GPS coordinates.

The data indicate that the brown bear is the main large herbivore, at least in nonalpine areas. Along a 1 km transect through riverine forests and tall-herb communities we observed a bear activity (feeding, track or faeces) every 17 m and a feeding activity every 50 m. The feeding was mainly observed on 1–4 m tall herbs like Filipendula kamchatica. The preliminary analyses also suggest that at Sites 1 and 4, the brown bear, in the absence of other large herbivores, causes most of the vegetation impact, both directly by grazing, and indirectly by e.g. trampling. Characteristic features of several other studied sites were mammal disturbances of the soil through digging and scraping. Several species, but mainly voles and ground squirrels (sousliks) are diggers. Within about 1.5 m from a 1 km long line on site 2, we found more than 200 holes of various sizes. Transect observations of a high density of soil disturbances through digging led to an extra study to better understand the spatial distribution of holes in an alpine area (site 2).

To estimate the insect herbivory we collected leaves of the dominant woody plants, herbs and grasses on the sites. The leaves were measured for morphological characters and we recorded length, breadth and the percentage of the leaf area affected by different types of herbivory (leaf-feeding and miners). On site 3 we also studied the level of insect herbivory along an altitudinal gradient.

At each site we selected 10–20 of the most common or apparent plant species and sampled shoots and leaves for later chemical analyses. In all 34 species were sampled, of which 2 species were taken at all 4 sites, 4 were taken at 3 sites and the majority of species were sampled just once. Five species were trees, 6 shrubs, 6 dwarf shrubs, 14 dicotyledonous herbs and 3 graminoids. For each species leaf length and leaf width were recorded, together with % leaf area consumed by herbivores (almost exclusively insects) and % leaf area that was necrotic, possibly a sign of hypersensitive response to insect herbivory.

Loss to herbivory was low, and on average across all species 0.6% of the leaf area was eaten and 0.17% was necrotic. Susceptibility varied both between species and between sites (tables 2 and 3). Neither herbivory nor necrosis were linearly related to leaf size, altitude or latitude when calculated across species.

Leaf width, but not length, across species was negatively correlated to altitude (at main sites: Regression analysis; R=0.390; F=9.529: p=0.003; N=34). Also within species and genera leaf size variables were in many cases negatively related to altitude (Alnus fruticosa, Betula spp., Pinus pumila, Rhododendron aureum, Salix spp., S. arctica).

The chemical defenses of plants

In order to test the hypothesis that Beringia plants have a different secondary plant chemistry we collected plant material from plants unique to Beringia and plants with a circumpolar distribution.

Relations to other projects on the Beringia 2005 expedition

To a large extent we collaborated with other projects on the Kamchatka part of the expedition and we used similar methods (estimates of herbivores and their impact; sampling of plants) to other scientists on the other legs of the Beringia 2005 expedition.

Some general impressions and ideas

Superficially the Kamchatka landscape and vegetation is rather similar to the one found in northern Scandinavia. The main difference is its volcanic origin, which has mainly affected soil properties. The Kamchatka landscape gives a “greener” impression than we see for example in the Scandinavian mountain range. On the slopes on Kamchatka there are two vegetation types (the Pinus and Alnus shrubs) which do not occur in Scandinavia. Besides giving the “green” impression, they really slow down walking. The lusher impression also persists in the mountain valleys, with impressive, high herb vegetation dominated by e.g. Filipendula kamchatika. The biological production is high, and the extensive cover of the nitrogen-fixing alder shrubs may be one main explanation. The nitrogen fixed on the mountain slopes is slowly transported to the mountain valleys with their luxurious vegetation. Our studies were to a large extent aimed at an increased understanding of how the soilplant–herbivore interactions may differ from Scandinavia and maybe, at a later stage, Alaska.