Larch Stands Research Articles

Ecophysiological Responses of Larix sibiricaLedeb. and Pinus sibiricaDu Tour Undergrowth to Climate Change

The effects of probable climate change—an increase in atmospheric CO2(by two times), air temperature, precipitation—on CO2exchange and temperature dependence of net photosynthesis in the larch and Siberian stone pine undergrowth formed in the light larch forests of West Siberia were studied in chambers with an artificial climate. The change of the aforementioned ecological factors caused an increase in the temperature optima of photosynthesis and the range of optimum temperatures (in the case of Siberian stone pine, to a slightly greater degree). Therefore, the ranges of both species may broaden, and the Siberian stone pine can expand to the north, displacing larch tree stands.

Damages to Trees by Sika Deer (Cervus nippon yezoensis HEUDE) in Young Artificial Larch Stands (I) : Relationships between Damage Rate and Typographical Factors

Damages to Trees by Sika Deer (Cervus nippon yezoensis HEUDE) in Young Artificial Larch Stands (I) : Relationships between Damage Rate and Typographical Factors

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.

Self-thinning exponents based on the allometric model in Chinese pine ( Pinus tabulaeformis Carr.) and Prince Rupprecht's larch ( Larix principis-rupprechtii Mayr) stands

The allometric power relationships of mean tree height H(∝ v θ) and stem volume packing d(∝ v δ) to mean stem volume v were investigated in 182 Chinese pine ( Pinus tabulaeformis Carr.) stands and 56 Prince Rupprecht's larch ( Larix principis-rupprechtii Mayr) stands. According to Weller's allometric model, the slope of the self-thinning boundary line, i.e. −1/[1−(θ+δ)], was calculated from the exponents of the allometric power relationships. The resulting slope was −1.79 for the larch and −1.72 for the pine. The self-thinning boundary lines corresponded well with the combinations of mean stem volume and density in the nine densest stands of pine and larch. The steeper slope for larch was attributed to allocation of more resources to height growth and to greater stem volume in space already occupied in the larch than in the pine, resulting in higher exponent values of θ and δ in the larch than in the pine.

Effect of vegetation and land use on soil fertility in Wutai Mountains of Shanxi Province

By comparison of several kinds stands, effect of vegetation and land use on the surface soil was investigated in Wutal Mountains of Shanxi Province. The result shows that larch (Larix principis-rupprechtii) and birch stands (Betula platyphylla) have more favourable influence on the properties of surface soil than pine (Pinus tabulaeformis) plantation and mixed plantation of pine and poplar (Populus cathayana). Since deciduous species forest had more annual litter and higher nutrient contents in the litter, thus much more nutrient returned to soil. Mixed planting of pine and poplar could largely improve the soil fertility because litter of poplar is greater in amount and decomposes within 1≈2a. The shrub lands contained high nutrient contents in leaves and relatively few human intervention, much of nutrient accumulates in the soil over a long period, resulting in higher nutrient contents in shrub land soil than that in pine plantation soil. Some of them, such as rose (Rosa bella), spiraea (Spiraea trilobata), ostryopsis (Ostryopsis davidiana) and bushclover (Lespedeza bicolor) dominant stands, have even higher nutrient status than larch and birch stands. Land-use could significantly change the soil fertility. Soil organic matter and nutrient contents decreased after shrub stand was cultivted as cropland, but increased largely to the pre-cultivated level during following period. It is recommended that larch is the optimum species in the afforestation activities in this area. Natural birch stand should be protected from further damage. Cultivation of shrub land should be stopped. The development and comprehensive utilization of shrub resources should be strengthened by the way of alternative cultivation.

Soil organic matter in European forest floors in relation to stand characteristics and environmental factors

Published data on the quantities of organic matter in the forest floor (SOMfl) of European forest stands were collated. Studies of SOMfl were included if the total sampled surface was at least 0.15 m2, the surface of a single sample was at least 100 cm2, live material was sorted out, and ash or carbon content was determined. Data from 59 forest stands were compared with regard to stand characteristics and environment. Using a single variable, tree genus was most important for the amount of SOMfl (R 2 adj = 0.34). The amounts in spruce stands (41 × 103 kg ha−1) were significantly higher than those in larch, Douglas fir, oak and birch stands (4–11 × 103 kg ha−1). The best significant multiple model was genus combined with stand age and basal area (R 2 adj. = 0.72). The importance of litter quantity and quality for differentiating the tree genera is discussed.

Soil nitrogen mineralization in adjacent stands of larch, pine and oak in central Korea

Afin d'examiner les effets de trois especes forestieres sur la mineralisation de l'azote du sol, nous avons mesure la vitesse de mineralisation de l'azote et de la nitrification dans les sols par la technique des sacs in situ dans des peuplements de meleze du Japon (Larix leptolepis Gordon), de pitchpin (Pinus rigida Mill) et de chene (Quercus serrata Thunb), âges de 37 ans et situes sur des sols similaires de Coree centrale. Litiere et sol mineral (0-15 cm) ont ete incubes pendant des periodes de 45 jours du 1 er septembre 1994 au 31 aout 1995. Les moyennes journalieres de mineralisation de l'azote etaient significativement differentes entre les trois especes forestieres. La mineralisation azotee annuelle a ete estimee a 44 kg/ha/an pour P rigida, a 92 pour L leptolepis et a 112 pour Q serrata. Le pourcentage de nitrification varie de 45 % pour P rigida a 90 % pour L leptolepis. La quantite d'azote apportee par la chute des litieres semble influencer la mineralisation de l'azote au sol. Cette etude montre que, dans des conditions stationnelles equivalentes, la mineralisation de l'azote peut varier, dans des rapports superieurs a un, sous l'effet de l'espece.

Wild boar ( Sus scrofa scrofa L.) rooting and forest regeneration on podzolic soils in the Netherlands

Phenology and the effects of rooting by wild boar on soil chemistry and forest regeneration were studied by stratified sampling, in deciduous and coniferous forests on acidic, podzolic soils in the central part of the Netherlands. At increasing degrees of soil scarification, three types of rooting were distinguished. Rooting phenology was dominated by superficial rooting in the litter layer, with highest frequencies in deciduous forests. Mast availability increased rooting activities in winter and summer, but the effects of season, soil morphology, or root abundance could not be established. No effect of rooting on soil pH, organic matter, and N-contents could be established. No evidence was found that singular, very intensive rooting, resulting in mixture of soil horizons, favoured conditions for germination and growth in stands of beech ( Fagus sylvestris), Douglas-fir ( Pseudotsuga menziesii), Japanese larch ( Larix kaempferi), and pedunculate oak ( Quercus robur). In practice, the boar visited the same spots regularly, and no effect of rooting could be established on regeneration of European black cherry ( Prunus padus), American black cherry ( P. serotina), birch ( Betula pubescens and B. pendula), rowan ( Sorbus aucuparia), holly ( Ilex aquifolium), Scots pine ( Pinus sylvestris), Douglas-fir, Norway spruce ( Picea abies), and Japanese larch. Regeneration of oak ( Quercus robur and Q. petraea), red oak ( Q. rubra), and beech was negatively correlated with rooting frequency.

Capercaillie habitat, diet and management in a Sitka spruce plantation in central Scotland

The ancestral habitat of capercaillie in most of its range is Scots pine forest with an understorey of blaeberry. Keillour forest in Perthshire is dominated by Sitka spruce, has little blaeberry, yet had a high density of capercaillie. Food and habitat use by capercaillie were studied there from 1991 to 1994. Seven cocks and two hens were caught, and marked with small radio transmitters. The habitats they occupied and food remains in their droppings provided information on home range, habitat utilization and diet through the year. Sitka spruce was the main food in autumn, winter and spring but was equalled by the fruiting heads of sedge in summer. Larch was the second most abundant item in spring and autumn diets. Sedge was plentiful on the wet restocks associated with the gleyed soils at Keillour and may provide a partial substitute for blaeberry in summer. Capercaillie showed a clear preference for the oldest blocks of trees, especially in winter. Sitka spruce, Norway spruce and Scots pine were used roughly in proportion to their availability in the birds' home range, but larch stands were used more than expected from availability. In summer, all birds used restocks to some extent. Management recommendations to encourage capercaillie in commercial plantations largely comprising exotics are that mature stands over 45 years and well-vegetated restocks should each occupy at least 20 per cent of the forest, larch and blocks of mixed conifers each at least 15 per cent of the ground. Blaeberry should be encouraged and, if possible, patches of windthrow involving living trees with the main root intact should be retained.

Wood properties of exotic larch grown in eastern Canada and north-eastern United States

The rapid growth performance of exotic larch such as Japanese larch (Larix leptolepis (Sieb. et Zucc) Gord.) and European larch (Larix decidua Mill.) has attracted the attention of the forestry sector in eastern Canada and north-eastern United States for lumber and pulp production. While growth performance of these species in North America has been well documented, little is known with regards to their wood properties. The objective of this study was to evaluate the primary lumber grade yields, mechanical properties, fiber length, specific gravity and cold-water soluble extractives of larch from plantations in Maine, Nova Scotia, New Brunswick and Prince Edward Island. Samples were obtained from a Japanese (age 31), three European (age 17, 34 and 63) and one Japanese × European hybrid (age 22-27) larch stands. It was found that the structural grade yields of these species were relatively low because of the influence of knots. The mechanical properties (modulus of rupture and modulus of elasticity) of the mature European larch appeared to be comparable with published data for some native softwood species. Fiber length, specific gravity and cold-water soluble extractive content of all samples were similar to those found for other softwood species which are used for pulp production. Fiber length of the juvenile wood of European larch was significantly shorter than that of mature wood. Extractive content was highest in newly formed heartwood. Contrary to common belief, extractive content in young trees may not be low. Key words: Japanese larch (Larix leptolepis Gord.), European larch (Larix decidua Mill.), European × Japanese hybrid (Larix eurolepis), Wood properties, Lumber yields

Causes of outbreak of the larch caterpillar (Dendrolimus superans Butler) in Daxingan Mountain and its control strategy

In 1991, in Daxingan Mountain, an outbreak of larch caterpillar (Dendrolimus superans Butler) happened on large areas of more than one million hectares, where stands of larch were seriously damaged because needles on the trees were almost eaten up by the pest, causing enormous economic losses. Analysis of data collected indicated that the main cause of the outbreak of larch caterpillar on large areas was that, after thirty years of exploitation, mature and overmature forests decreased rapidly, middle-aged and young forests incresed in large amount, significant changes occurred in individual ecological conditions of stands, especially those tended, with decreasing canopy density and better light condition in the forest, and all these were adventageous to the outbreak of the pest. In addition, in recent years, the climatic condition in Daxingan Mountain changed significantly. The yearly average temperature raised gradually and the soil surface temperature in April and October increased year by year, which were advantageous to the outbreak of larch caterpillars. In short, the significant changes in the ecological conditions in Daxingan Mountain provided suitable conditions for the outbreak of the larch caberpillar, and after several years of increase in population number, the larch caterpillar outbroke into a serious disaster on vast areas. In the paper, composite control strategy was also discussed.

Temperature Effects on Bud-Burst and Leaf-Fall in Subalpine Larch

Phenology was monitored in natural stands of subalpine larch (Larix lyallii Parl.) in parts of four decades. Bud-burst date varied by about six weeks from year to year, and leaf-fall date by a month, suggesting that the importance of photoperiod in these processes has been over emphasized, even in the case of leaf-fall. Most of the variation in bud-burst date is accounted for by spring temperature, while date of leaf-fall depends on both spring and summer temperatures. This rather curious observation might be explained in terms of heat-mediated leaf aging. Early bud-burst, due to warm temperatures in spring, results in early leaf-fall, and warm summers also tend to terminate the life of the leaves sooner, from which it might be inferred that longevity is governed by a heat-sum above a certain threshold temperature. In controlled environments it was shown that the threshold temperature for bud-burst is very low, less than 1.5OC, and the heat-sum requirement is less than 75 degree-days above this threshold. This is the cause of the extremely early flushing date of subalpine larch relative to that of it's common associates.

Arthropod Diet of Pileated Woodpeckers in Northeastern Oregon

We examined 330 samples of scat collected from 23 individual pileated woodpeckers (Dryocopus pileatus) from August 1989 to August 1990. Based on arthropod mandibles found in the scats, the diet was 68% carpenter ants (Camponotus spp.), 29% thatching ants (Formica spp.) and other ants, 0.4% beetles (Coleoptera), and 2% other. Diet changed seasonally with none or few (0-11%) of the thatching and other ants found from November to February, but these ants comprised most of the diet from June until September. Carpenter ants were found in the diet in all months. Scats collected from the roost cavity of one bird contained 170 mandibles of western spruce budworm (Choristoneura occidentalis) and 259 mandibles of an unknown Isoptera. Knowing the diet of any species is important in understanding its foraging ecology. Diet of the pileated woodpecker (Dryocopus pileatus) has been described in the eastern United States and includes insects (primarily ants and wood-boring beetle larvae) all year and some fruits and nuts in the fall (Conway 1957; Hoyt 1957). Bent (1939) reported stomach contents of three birds to contain ants, beetle larvae, and fruits and seeds. Beckwith and Bull (1985) found that this species feeds primarily on ants in northeastern Oregon. Our objective was to determine the arthropod diet of D. pileatus over time in northeastern Oregon. STUDY AREA AND METHODS The study was conducted in the Blue Mountains in northeastern Oregon in Baker, Umatilla, Union, and Wallowa Counties. We collected scats from birds in six study areas within 200 km of either La Grande or Wallowa, Oregon. The study areas were in mixed conifer forests; scattered grasslands comprised 4-14% of these areas. The forests were predominantly mature, uneven-aged stands of grand fir (Abies grandis), Douglas-fir (Pseudotsuga menziesii), ponderosa pine (Pinus ponderosa), western larch (Larix occidentalis), and lodgepole pine (Pinus contorta). Two of the study areas had been high-graded 40 years ago, three had partial overstory removals about 20 years ago, and one had been extensively logged (clearcut and shelterwood) within the last 15 years. We captured 23 adult D. pileatus in summer (mid-June to mid-August) 1989 and attached 11 g 2-stage transmitters to them. Each bird was followed 1-3 times each week for 1-3 hours until March 1990 when we retrapped the birds and removed the transmitters. During the time each bird was followed, we collected scats when possible. To locate fresh scats, we searched each foraging site or resting site after the bird flew away. We found scats in June 1989, in each month from August 1989 to March 1990, and in August 1990. The scats found 1 August 1990 were collected from the roost cavity of a pileated woodpecker. These probably had been defecated in July because the bird had been roosting in this cavity for several weeks, so we included this sample in July. Scats were difficult to collect in June and July because the birds were often feeding in the tops of trees, and scats were virtually impossible to find on the ground. The characteristic large size of the scat is unique to this woodpecker, and we used the technique of scat analysis described by Beckwith and Bull (1985). This technique primarily identifies arthropod parts because plant material may not be detected. We assumed that the mandibles and other arthropod remains in the scat represented the entire diet. We collected 330 samples: 313 were subsampled, 11 were used in a regression analysis, and 6 (32 individual scats) were collected from a roost. Each of 313 scat samples was dried for 12 hours at 300C and weighed to the nearest 0.001 g on an analytic balance. A subsample was taken for examination

REMOTE SENSING IN THE ASSESSMENT OF VEGETATION CONDITION

A survey of test sites is undertaken to determine the general correspondence between various biological and spectral characteristics of the plant cover. More specifically, the relationships are explored between such vegetation characteristics as leaf pigmentation, moisture content, phytomass, and pollution by coal and cement dust and such spectral parameters (and their derivatives) as spectral brightness coefficients and normalized vegetation indices. The sensors employed include a spectrometer and two different radiometers (overall spectral resolution 0.4 to 22 μm) and the features analyzed include pine, larch, aspen, birch, and mixed tree stands, as well as a grassland plot. Translated by Elliott B. Urdang, Providence, RI 02906 from: L. N. Vasil'yev, ed., Kosmicheskiye metody izucheniya biosfery [Remote Sensing Methods in the Study of the Biosphere]. Moscow: Nauka, 1990, pp. 59–66.

Susceptibility of injury-experienced trees to vole attacks and shape of gnawing traces in old larch (Larix leptolepis) stands

Susceptibility of injury-experienced trees to vole attacks and shape of gnawing traces in old larch (Larix leptolepis) stands

Effects of Thinning on Volume Growth of Western Larch Infected with Dwarf Mistletoe in Northeastern Oregon

Abstract Cubic volume growth and tree vigor of 70-year-old western larch (Larix occidentalis) with and without dwarf mistletoe (Arceuthobium laricis) were measured 15 years after thinning from above or below to residual densities of 50 to 170 ft²/ac. Vigor was assessed by cambial electrical resistance (CER). Proportional volume growth increased after thinning; was significantly related to the interaction of thinning method and residual density; and decreased with increased dwarf mistletoe severity. Thinning from above was associated with significantly higher proportional volume growth, but led to increased mortality from snow and ice damage to infected trees. CER was significantly related to severity of infection but not to treatment. Thinning is recommended in dwarf mistletoe infested stands of western larch to increase volume growth and reduce new infections in residual trees. West. J. Appl. For. 4(4):143-145, October 1989.

PRODUCTIVITY OF WESTERN LARCH AND SUBSOIL PERCOLATION RATES ON POOR ANDIC SOILS

We observed low nutrient levels and poor productivity in andic soils overlying glacial till with differential percolation characteristics in northwestern Montana. The objective of this study was to determine whether variation in the subsurface percolation rate of underlying glacial till significantly affected (1) the nutrient content of the andic surface soil and (2) timber production on the andic soils. Twenty sample sites supporting 50-year-old stands of western larch (Larix occidentalis Nutt.) were selected on the Kootenai National Forest. Grouping of the soils was based on slow, (<2.54 cm/h), moderate (2.54 to 25.4 cm/h), and fast (>25.4 cm/h) internal subsoil (till percolation). Soil nutrient concentrations and availabilities, tree growth indicators, xylem sap nutrient contents, and tree moisture stress were measured. The results supported the hypothesis that the rate of subsoil percolation affected the overall fertility of andic soils. Tree growth was affected by the subsoil percolation rate as it related to moisture availability. There is some evidence that trees on the slowly draining sites that had the best juvenile growth were growing more slowly with age because of nutrient depletion in the shallow andic soil where the roots were confined by compacted silts. Trees on the rapidly draining sites were growing better with age, because the roots were able to penetrate more broadly into the underlying gravel that was not strongly compacted.

Evaluation of (Z)-5-Decen-1-ol as an Attractant for Male Larch Casebearer Moths, Coleophora laricella

Electroantennogram studies on C. laricella males demonstrated that the title compound, (Z)-5-decen-l-ol (Z5-10:OH), elicited the highest response among a series of straight-chain, C10 to C16 alcohols, acetates and aldehydes tested. From selective adaptation of antennal responses it was concluded that an additional type of receptor cell responded to the corresponding acetate, Z5-10: Ac. Field attraction experiments were carried out by using delta-type sticky traps and rubber-cap odour dispensers. The main test sites were located in the Swiss Alps, Black Forest and northwestern Germany, and included both European and Japanese larch stands, having different degrees of C. laricella infestations. At all test sites pure Z5-10:OH proved to be highly attractive to native male moths over a range of different lure doses, with a progressive increase of captures towards the higher (100 μg, 1000 μg) attractant sources. However, following captures of 200-400 moths/trap the “retaining capacity” of the sticky surfaces of the traps were found to decline markedly; in tests of the higher attractant doses at sites of higher moth densities, this “saturation effect” frequently occurred within a few hrs of trap exposure, thus demonstrating the limitation in the use of sticky traps for monitoring economically-relevant C. laricella populations. Trap placement studies (using the standard attractant of 100 μg Z5-10:OH) showed substantial captures only for those traps placed on green branches within the host crowns. The acetate analogue (Z5-10:Ac) strongly reduced male responses to the attractant alcohol (Z5-10:OH) when evaporated from the same trap, admixtures of 0.3% and 1% of this acetate reducing captures by 90% and almost 100% respectively. Possible functions of this inhibitor are briefly considered. No evidence for attractant synergism was obtained during the present study. The results suggest that Z 5-10: OH is a major constituent of the yet unidentified C. laricella sex pheromone.

The Place of the Self-Thinning Rule in Population Dynamics

The Place of the Self-Thinning Rule in Population Dynamics

Sampling Distributions of Larch Casebearer, Coleophora laricella , on Western Larch 1

Intensive sampling of larch stands in northern Idaho shows that densities of overwintering larch casebearer larvae are clustered on the distal tips of branches. There is no difference in densities of pupating larvae on roadside larch trees as opposed to larch trees interior to a stand. With appropriate scaling, sample densities of overwintering and pupating larvae on the same or different plots can be compared. The distributions of sample densities among diverse larch stands are similar enough that a standardized sequential procedure can be used to efficiently and confidently monitor predicted defoliation of the larch trees. An appropriate sampling technique is presented.