Mountain Taiga Research Articles

Insect and small mammal herbivores limit tree establishment in northern Mongolian steppe

The extent to which human activities expanded the range of central and north-eastern Asian steppes into the forest is controversial. Natural versus anthropogenic causes of the inhibition of tree growth were investigated in a case study in the western Khentey Mountains in montane meadow steppe on sun-exposed southern slopes, representing treeless outposts within the northern Mongolian mountain taiga. Sowing and planting experiments with Mongolia’s most common tree species, Larix sibirica, did not result in the successful establishment of any tree during one growing season, despite the exclusion of grazing by large herbivores from the sample plots by fencing. Less than 1% of the seeds germinated 4 weeks after sowing in spring. All seedlings died within a further 3 weeks due to drought and heat. Two-year-old seedlings suffered from drought as well as from feeding by of gypsy moth larvae (Lymantria dispar), grasshoppers and rodents. While the gypsy moth was effective at damaging L. sibirica only during few weeks at the beginning of the growing season, feeding by grasshoppers and rodents persisted through the entire growing season. At the end of the growing season two thirds of the seedlings died due to insect and small mammal herbivory and one third due to drought-related damage. Herbivores attacked larch seedlings more rapidly on the open meadow steppe than at the forest edge. Drought and high temperature at the soil–air interface are crucial for inhibiting tree encroachment on the studied steppe slopes. Competition by non-arboreal plants is of subordinate significance for the establishment of L. sibirica. Trees can only establish at especially favorable microsites under humid weather conditions. Such trees, however, are exposed to a high risk of mortality from insect or small mammal herbivory.

Trends of changes in the floristic composition of forest vegetation in the northern Baikal region upon climate warming

Parameters characterizing the activity of species in altitudinal zonal elements of the flora have been analyzed in the northern Baikal region. The results provide evidence for the weakening status of xerophilic species in the cenoflora of hemiboreal light coniferous forests of the class Rhytidio-Laricetea, which form the lower part of the forest belt bordering the steppe. This fact indicates that climate on the slopes of mountain ridges is becoming more humid. The increase in humidity may be explained by both progressing degradation of permafrost and increasing precipitation. On the other hand, no significant change has been observed in the cenoflora of mountain taiga forests of the class Vaccinio-Piceetea, which form the upper part of the forest belt.

Snow ablation in an open field and larch forest of the southern mountainous region of eastern Siberia

The southern mountainous taiga region of eastern Siberia is the runoff source area of the basins of the rivers Lena and Amur, where snowmelt discharge is an important hydrological process. To evaluate the effect of the sparse larch forest canopy on snow ablation and energy balance in the snow-pack, meteorological conditions and snow ablation were observed in a larch forest (LF) and an open field (OP). At the beginning of snowmelt, the snow water equivalent was 54.4 and 95.5 mm at OP and LF, respectively. The snow disappeared at LF three days later than at OP. Sublimation accounted for about 8% of snow ablation at both sites from 1 April to 5 May 2002, the snowmelt period. The energy balance of the snowpack at the two sites was dominated by the net all-wave radiation onto the snow surface. The difference in snowmelt between the sites was primarily caused by a difference in the net all-wave radiation. Snow surface albedo correlated with snow surface density for densities from 150 to 350 kg m−3 at both sites.

Transport of organic carbon from the Mogot Experimental Watershed in the southern mountainous taiga of eastern Siberia

More than 60% of river runoff from the Lena River basin originates in the southern mountainous region of eastern Siberia within the permafrost zone. We studied the transport of dissolved organic carbon (DOC) and particulate organic carbon (POC) within the Mogot Experimental Watershed, which is close to the drainage divide between the Lena and Amur River basins in the southern mountainous taiga region, from 1 August 2000 to 12 November 2001. DOC concentration was strongly related to thawing depth at the bottom of the main valley when thawing depth was less than 20 cm during snowmelt runoff. When thawing depth was equal to or greater than 20 cm, DOC concentration was more closely related to the rate of river discharge in summer runoff. On the basis of our observations, we extrapolated the annual transport of DOC and POC to be 4.75 g C m−2 yr−1 and 0.03 C kg C m−2 yr−1, respectively. Transport of organic carbon from the catchment was about 4.78 g C m−2 yr−1 during 2001. DOC is the main form of organic carbon flux in the study area.

Influence of snow ablation and frozen ground on spring runoff generation in the Mogot Experimental Watershed, southern mountainous taiga of eastern Siberia

Snowmelt runoff is one of the most important discharge events in the southern mountainous taiga of eastern Siberia. The present study was conducted in order to understand the interannual variations in snowmelt infiltration into the frozen ground and in snowmelt runoff generation during the snowmelt period in the southern mountainous taiga in eastern Siberia. Analysis of the obtained data revealed the following: (1) snowmelt infiltration into the top 20 cm of frozen ground is important for evaluating snowmelt runoff generation because frozen ground absorbed from 22.9% (WY1983) to 61.5% (WY1981) of the maximum snow water equivalent. The difference in snowmelt infiltration for the two years appears to have been caused by the difference in snowmelt runoff generation; (2) the snowmelt runoff ratio increased with (i) increase in the fall soil moisture just before the soil surface froze and (ii) increase in the maximum snow water equivalent. The above results imply that the parameters governing snowmelt infiltration in the boreal taiga region in eastern Siberia are fall soil moisture and the maximum snow water equivalent, as is the case in the simple model presented by Gray et al.

Life Cycles of Ground Beetles (Coleoptera, Carabidae) from the Mountain Taiga and Mountain Forest-Steppe in the Eastern Sayan

Seasonal dynamics and demographic structure was studied in 15 dominant ground beetle species in the mountain taiga and mountain forest-steppe belts of the Eastern Sayan (Okinskoe Plateau). Life cycles of the dominant ground beetle species were classified by developmental time, seasonal dynamics, and intrapopulation groups with different reproduction timing. The strategies of carabid life cycles adapted to severe mountain conditions of the Eastern Sayan were revealed.

Correction to “Sublimation from snow surface in southern mountain taiga of eastern Siberia”

[1] In the paper ‘‘Sublimation from snow surface in southern mountain taiga of eastern Siberia’’ by Yiensheng Zhang, Kazuyoshi Suzuki, Tsutomu Kadota, and Tetsuo Ohata (Journal of Geophysical Research, 109, D21103, doi:10.1029/2003JD003779, 2004), the first author’s name was misspelled. The correct spelling appears above. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 110, D08109, doi:10.1029/2005JD005902, 2005

Features of the life cycles of Pterostichus montanus (Motschulsky, 1844) and Carabus loschnikovi (Fischer-Waldheim, 1822) (Coleoptera, Carabidae) in conditions of the mountain taiga belt in the Eastern Sayan

We studied the seasonal dynamics and demographic structure of abundant ground beetle species from the mountain taiga belt in the Eastern Sayan. Data on the dynamics of the sexual and age structure of the populations as well as on the reproductive capacity of females in the biotopes on the slopes with different exposure and height were obtained. Life cycles with one- and two-year development were revealed for the ground beetles typical for the mountain taiga belt. As an example, data on the life cycles of Pterostichus montanus (Motschulsky, 1844) with one-year spring development and Carabus loschnikovi (Fischer-Waldheim, 1822) with two-year polyvariant multiseasonal development are given for the first time. Two strategies were revealed in the life cycles of ground beetles under alpine conditions: an accelerated population development in spring one-year species and a two-year development with pronounced polyvariance in two intrapopulation groups of ground beetles of the Carabus genus. The seasonal dynamics of the activity and reproduction periods proved to vary for these species on the slopes along the height gradient.

The Impact of Snow Processes on Snowmelt Runoff Generation in the Southern Mountain Taiga, Eastern Siberia

The Impact of Snow Processes on Snowmelt Runoff Generation in the Southern Mountain Taiga, Eastern Siberia

Sublimation from snow surface in southern mountain taiga of eastern Siberia

Through intensive observations of snow sublimation and meteorological elements, cold season processes at the snow‐atmosphere interface were clarified for both forested and open field conditions in the taiga region of eastern Siberia. Sublimation from snow surfaces differed with atmospheric stability. During early spring a significant difference in snow sublimation was observed between slopes and valley bottoms, despite variable vegetation cover. However, during the observation period, only one episode of significant snow sublimation was observed, which was caused by strong wind and ensuing light snowmelt. The sublimation for that week was ∼50% of the sublimation observed in the study period (29 days). As atmospheric stability decreased, the effect of forest cover on snow sublimation was clear, with a significant difference between forested areas and open fields. Later in the spring, increased net all‐wave radiation did not lead to an increase in sublimation but was consumed in meltwater production. The effect of forest cover on snow sublimation can be seen from the estimated bulk transfer coefficient for latent heat. The bulk transfer coefficient was larger for a larch forest than was that of open site. In the period 13 March–22 April (48 days), total snow sublimation was 15.7, 12.1, and 10.4 mm for open field, larch forest, and larch forest on a slope, respectively. This represents 14.3%, 13.0%, and 7.6% of the maximum water‐equivalent snow cover, respectively. However, the study period was only a part of the entire snow season, so totals for the whole winter would be larger.

Palaeoecological evidence of changes in vegetation and climate during the Holocene in the pre‐Polar Urals, northeast European Russia

AbstractThis study investigated Holocene tree‐line history and climatic change in the pre‐Polar Urals, northeast European Russia. A sediment core from Mezhgornoe Lake situated at the present‐day alpine tree‐line was studied for pollen, plant macrofossils, Cladocera and diatoms. A peat section from Vangyr Mire in the nearby mixed mountain taiga zone was analysed for pollen. The results suggest that the study area experienced a climatic optimum in the early Holocene and that summer temperatures were at least 2°C warmer than today. Tree birch immigrated to the Mezhgornoe Lake area at the onset of the Holocene. Mixed spruce forests followed at ca. 9500–9000 14C yr BP. Climate was moist and the water level of Mezhgornoe Lake rose rapidly. The hypsithermal phase lasted until ca. 5500–4500 14C yr BP, after which the mixed forest withdrew from the Mezhgornoe catchment as a result of the climate cooling. The gradual altitudinal downward shift of vegetation zones resulted in the present situation, with larch forming the tree‐line. Copyright © 2003 John Wiley & Sons, Ltd.

Displaying behaviour and mating system in the Siberian Spruce Grouse (Falcipennis falcipennis Hartlaub 1855)

The Siberian Spruce Grouse (Falcipennis falcipennis) is a species endemic to far-eastern Russia and a close relative toF. canadensis andF. franklinii of North-America. Prior to this study, little was known about the display behaviour, social organisation and seasonal movements of this grouse. We investigated these topics in 1990–1997, in 2 areas, 100 km N and 200 km NW of Komsomolsk/Amur. We caught, measured and marked 80 individuals. We determined the age of cocks by the size of combs and the length of neck feathers. Spatial organisation of the local population was studied by equipping 60 birds with transmitters and following them all-year-round. During the reproductive period males and females were territorial. Winter flocks (2–6 birds) break up by late March or early April, and spring flocks break up 1 month later. Cocks were present at the display ground from April 1 to May 25. Females visited the display grounds from April 25 to May 10. Eggs were laid between May 7 and May 20. The main display performances of cocks (upright posture and tail flicks, walks with tail swish, flutter jumps, flutter flights, drumming flights), courtship and agonistic behaviour were analysed from photographs and video recordings. Three-year-old cocks carried out most of the copulations. During the “high season” of display, we recorded activity (morning and evening displays, moving versus roosting) during continuous observations and counted flutter jumps, flutter flights and drumming flights. Parts of the displays of the Siberian spruce grouse are more diversified than those of the North-American species. The communication system is perfectly adapted to the dense habitat of the mountain taiga. Different acoustic signals for communication at very short, medium and longer distances seem to have evolved under specific predation pressure. The territorial system is very flexible, ranging from individual display grounds to an arena-like structure. The mating system is polygyny.

Environmental Safety of the Development of Water Resources at Hydromineral Deposits: Water Protection Zoning

The development of the Znamenskoe deposit of industrial brines, situated in the valley of a mountain taiga river, with account taken of the legal regulations and scientific recommendations, is used to work out a method of water protection zoning.

Картографирование динамики растительного покрова Саяно-Шушенского заповедника

The character of forest dynamics in the last century may be traced on the key area of the Altai-Sayan mountain country — the Sayan-Shushensky Biosphere Reserve of total area 389 000 ha. It is situated at the border of humid mountain region of South Siberia and the arid areas of Tuva. The basement for creation of prognosis map of potential state of the Reserve vegetation cover for 2050 year includes: 1) the data on inventory, ages structure, and conditions of forests; 2) the results of the earlier studies of dynamics of mountain open woodlands; 3) materials of dendroclimatic investigations at the upper and lower forest boundaries in the Sayan Mts.; 4) prognosis of climatologists. While classifying the Reserve vegetation, 1500 biogeocoenoses have been united into 362 types of biogeocoenoses which have been included into 112 groups of associations identified in altitudinal vegetation belts: goltsy, meadows and shrub thickets; high elevation open woodlands; mountain taiga; subtaiga—forest- steppe complexes. Local expansion of forest boundaries, at the expense of forming the 40— 80 years old forest stands in goltsy and open woodlands, testifies to climate warming, and a rise of the subtaiga—forest-steppe pine and larch forests of the 40—80 years old is the evidence of climate humification in this region during the last century. According to the prognoses of climatologists this tendency will continue in the future 50 years. On the territory of the Sayan-Shushensky Reserve, within the strip of 200 m width at the age of steppefied forests as well as within the steppes with shrubs, mesophilous species will be developed in the shrub, herb-dwarf shrub and moss cover. Under protection of shrubs, young open stands of larch and pine will spring up (on the area of 200 ha) and in subtaiga forests Abies sibirica and Pinus sibirica will appear among the regrowth. Under canopy of the mountain taiga and the subtaiga larch forests, the second layer of dark needle-leaved species will be formed. In the places of present pyrogenic derivatives — birch and aspen forests — the fir forest with admixture of Pinus sibirica and Picea obovata will be restored. On the area of 49 322 ha, occupied by mountain woodlands (87% of the total area), the closed mountain taiga forest of Pinus sibirica will spread. The area of goltsy and shrub thickets will decrease by 44.4% (19 214 ha), being replaced by the high elevation open woodlands of Pinus sibirica and Larix sibirica. In accordance with changes in vegetation cover the boundary between the Altai-Sayan and the Central-Asian forest areas within the Reserve's territory will deviate from the modern one approximately by 25 km.

Возможные изменения растительности Горного Алтая при потеплении климата и составление прогнозных карт

Global climate warming is expected to be a new factor influencing vegetation redistribution and productivity in the XXI century. In this paper possible vegetation change in Mountain Altai under global warming is evaluated. The attention is focused on forest vegetation being one of the most important natural resources for the regional economy. A bioclimatic model of correlation between vegetation and climate is used to predict vegetation change (Parfenova, Tchebakova 1998). In the model, a vegetation class — an altitudinal vegetation belt (mountain tundra, dark- coniferous subalpine open woodland, light-coniferous subgolets open woodland, dark-coniferous mountain taiga, light-coniferous mountain taiga, chern taiga, subtaiga and forest-steppe, mountain steppe) is predicted from a combination of July Temperature (JT) and Complex Moisture Index (CMI). Borders between vegetation classes are determined by certain values of these two climatic indices. Some bioclimatic regularities of vegetation distribution in Mountain Altai have been found: 1. Tundra is separated from taiga by the JT value of 8.5°C; 2. Dark- coniferous taiga is separated from light-coniferous taiga by the CMI value of 2.25; 3. Mountain steppe is separated from the forests by the CMI value of 4.0. 4. Within both dark-coniferous and light-coniferous taiga, vegetation classes are separated by the temperature factor. For the spatially model of vegetation distribution in Mountain Altai within the window 84 E — 90 E and 48 N — 52 N, the DEM (Digital Elevation Model) was used with a pixel of 1 km resolution. In a GIS Package IDRISI for Windows 2.0, climatic layers were developed based on DEM and multiple regressions relating climatic indices to physiography (elevation and latitude). Coupling the map of climatic indices with the authors' bioclimatic model resulted into a vegetation map for the region of interest. Visual comparison of the modelled vegetation map with the observed geobotanical map (Kuminova, 1960; Ogureeva, 1980) showed a good similarity between them. The new climatic indices map was developed under the climate change scenario with summer temperature increase 2°C and annual precipitation increase 20% (Menzhulin, 1998). For most mountains under such climate change scenario vegetation belts would rise 300—400 m on average. Under current climate, the dark-coniferous and light-coniferous mountain taiga forests dominate throughout Mountain Altai. The chern forests are the most productive and floristically rich and are also widely distributed. Under climate warming, light-coniferous mountain taiga may be expected to transform into subtaiga and forest-steppe and dark-coniferous taiga may be expected to transform partly into chern taiga. Other consequences of warming may happen such as the increase of forest productivity within the territories with sufficient rainfall and the increase of forest fire occurrence over territories with insufficient rainfall.

Maximum oxygen consumption and heat loss facilitation in small homeotherms by He-O2.

ROSENMANN, MARIO, AND PETER MORRISON. Maximum oxygen consumption and heat loss facilitation in small homeotherms by He-02 . Am. J. Physiol. 226(3) : 490495. 1974.-The high thermal conductance of an 80% He-20y0 02 atmosphere was used to elicit maximum metabolism (Mmax) in moderate cold in species ranging from 7-g pygmy mice (Baiomys taylori) to 250-g white rats, including redpolls (Acanthis J?ammea), two vesper mice (Calomys d&la, C. callosus), tundra voles (Microtus oeconomus), and four strains of Mus musculus. Values slightly exceeded those in similar animals using other methods to confirm the low metabolic ratio (Mmax/M, in) in rodents (4-8 X). Submaximal values at higher temperatures defined thermal conductance in He-02 and air. In different species the ratios of these conductances ranged from 1.4 to 2.6, differences which relate to the extent and quality of the respective insulation. M,,, was obtained at 13-70°C warmer in He-02 than required in air for the same metabolic effort. Avoidance of low-temperature technology and freezing injury, elimination of treadmills and training in running, prompt attainment of M,,., (3-10 min after He-02 exposure), and obviation of shaving or wetting procedures are advantages of the present technique.