Timber Line Research Articles

Clean production of laminated bamboo timber and efficient utilization of bamboo

ABSTRACT To reduce the environmental impact, the environmental impact of the Laminated bamboo timber (LBT) line has been assessed using Life Cycle Assessment (LCA), and the environmental impacts of four scenarios has been compared in this article. The environmental impact can be effectively reduced if the bamboo residues is burned instead of lignite to provide steam for the LBT production line. Global warming potential (GWP-100) can be reduced by 21.81%, acidification potential (AP) by 51.73% and eutrophication potential (EP) by 57.18%. In addition, the utilization rate of bamboo can be increased by 29.07% and the economic benefit can be increased by 34.73%. When the bamboo shavings from the bamboo strip rough processing stage are used to produce bamboo barbecue charcoal (BBC), the GWP-100 of the LBT line is reduced by 17.49%. And the utilization rate of bamboo can be further increased by 30.90% and the economic benefit can be further increased by 12.47%. When the GWP-100 of the BBC production is added to the GWP-100 of the LBT production line, there is a slight increase of 5.06% in the total GWP-100. However, it doesn’t make much difference whether the bamboo strip roughing workshop is located next to the LBT production line.

Dynamics of the Alpine Treeline Ecotone under Global Warming: A Review

The alpine treeline ecotone is defined as a forest-grassland or forest-tundra transition boundary either between subalpine forest and treeless grassland, or between subalpine forest and treeless tundra. The alpine treeline ecotone serves irreplaceable ecological functions and provides various ecosystem services. There are three lines associated with the alpine treeline ecotone, the tree species line (i.e., the highest elevational limit of individual tree establishment and growth), the treeline (i.e., the transition line between tree islands and isolated individual trees) and the timber line (i.e., the upper boundary of the closed subalpine forest). The alpine treeline ecotone is the belt region between the tree species line and the timber line of the closed forest. The treeline is very sensitive to climate change and is often used as an indicator for the response of vegetation to global warming. However, there is currently no comprehensive review in the field of alpine treeline advance under global warming. Therefore, this review summarizes the literature and discusses the theoretical bases and challenges in the study of alpine treeline dynamics from the following four aspects: (1) Ecological functions and issues of treeline dynamics; (2) Methodology for monitoring treeline dynamics; (3) Treeline shifts in different climate zones; (4) Driving factors for treeline upward shifting.

Palaeovegetation and climatic variations in the Parvati Valley, Himachal Pradesh, India since last deglaciation

Pollen proxy records from 1.2 m deep sediment profile from Tundabhuj, Parvati Valley (H.P.) reveals that between 15,260 and 13,280 yr BP, the sub–alpine belt supported alpine–scrub vegetation dominated by Betula and thermophillous broad–leaved allies viz. Quercus, Corylus and Carpinus, interspersed with meadows comprising grasses, Asteraceae, Impatiens, etc. under a warm and moderately moist climate. The dry scrubby element, Juniperus occurred in restricted pockets on the sunny mountain slopes. The frequent record of conifers such as Pinus cf. wallichiana, Cedrus, Abies and Picea implies the proximity of the temperate belt to the study site. Around 13,280 to 7,340 yr BP, the considerable expansion of Betula and broad–leaved allies and a simultaneous reduction in Juniperus elucidate the replacement of alpine scrub forests by temperate Betula–broad–leaved forest in response to onset of a relatively warm and more–moist climate. This change occurred by the upward shift of the timber line as reflected by the improvement in the conifers. The climate deteriorated and turned cold and dry around 7,340 to 5,030 yr BP as manifested by the abrupt reduction in the alpine–scrub vegetation and meadow constituents. Subsequently, between 5,030 and 2,000 yr BP this region witnessed a warm and moist climate again as evidenced from moderate expansion in the alpine–scrubs and conifers. Since 2,000 yr BP onwards deterioration in climate is demonstrated by the depletion in Betula and broad–leaved associates and substantial increase in Juniperus and Ephedra.

Snow Cover Dynamics and its Spatio-Temporal Distribution in the Central Higher Himalaya of India

Retreating glaciers, changing timber line and decreasing accumulation of snow in the Himalaya are considered the indicators of climate change. In this study, an attempt is made to observe the snow cover change in the higher reaches of the Central Himalayas. Investigation of climate change through snow cover is very important to understand the impact and adaptation in an area. Landsat thematic and multi spectral optical data with a spatial resolution of 60m and 30m are considered for the estimation and extraction of snow cover. Total 3,369 Km2 snow cover area is lost since 1972 out of total geographical area i.e. 17,227 Km2. The accumulation of snow during winter is lower than the melting rate during summer. The current study identified the decrease of 19.6 % snow cover in 47 years since 1972 to 2019. Composite satellite imageries of September to December show that the major part of the study area covered with snow lies above 3600m. Overall observation indicates that in 47 years, permanent snow cover is decreasing in Central Himalayas.

Elevational variation in voltinism demonstrates climatic adaptation in the dark bush‐cricket

1. Phenotypic plasticity and/or genetic adaptation may allow species to live in a variable environment. It has been shown that eggs of the dark bush‐cricket, Pholidoptera griseoaptera, which experienced an insufficient warm treatment (shorter and/or colder), had a longer development time and hatched predominantly after the second diapause.2. Given the broad distribution of this species from sea level to the timber line, we expected variation in voltinism along a climatic gradient. To reveal the role of natural selection in egg‐hatching patterns, we compared different and unrelated populations sampled along a 1000 m elevational gradient in a common laboratory experiment.3. In the same rearing microclimate, we found that populations from mountains had mostly a shorter life cycle, whereas semivoltinism prevailed in lowland populations.4. This demonstrated the genetically underpinned local adaptation of this insect to harsh mountain environments with a shorter growing season determined by elevation.

Tree Line Identification and Dynamics under Climate Change in Wuyishan National Park Based on Landsat Images

The alpine tree line ecotone, reflecting interactions between climate and ecology, is very sensitive to climate change. To identify tree line responses to climate change, including intensity and local variations in tree line advancement, the use of Landsat images with long-term data series and fine spatial resolution is an option. However, it is a challenge to extract tree line data from Landsat images due to classification issues with outliers and temporal inconsistency. More importantly, direct classification results in sharp boundaries between forest and non-forest pixels/segments instead of representing the tree line ecotone (three ecological regions—tree species line, tree line, and timber line—are closely related to the tree line ecotone and are all significant for ecological processes). Therefore, it is important to develop a method that is able to accurately extract the tree line from Landsat images with a high temporal consistency and to identify the appropriate ecological boundary. In this study, a new methodology was developed based on the concept of a local indicator of spatial autocorrelation (LISA) to extract the tree line automatically from Landsat images. Tree line responses to climate change from 1987 to 2018 in Wuyishan National Park, China, were evaluated, and topographic effects on local variations in tree line advancement were explored. The findings supported the methodology based on the LISA concept as a valuable classifier for assessing the local spatial clusters of alpine meadows from images acquired in nongrowing seasons. The results showed that the automatically extracted line from Landsat images was the timber line due to the restriction in spatial autocorrelation. The results also indicate that parts of the tree line in the study area shifted upward vertically by 50 m under a 1 °C temperature increase during the period from 1987 to 2018, with local variations influenced by slope, elevation, and interactions with aspect. Our study contributes a novel result regarding the response of the alpine tree line to global warming in a subtropical region. Our method for automatic tree line extraction can provide fundamental information for ecosystem managers.

Habitat Selection of Skylarks During the Breeding Season on the Volcanic Slope of Mt. Tarumae

The Eurasian Skylark, Alauda arvensis, is a passerine bird that mainly breeds in open habitats, such as lowland grasslands and farmlands. However, recent studies have shown that they form breeding territories on volcanic and alpine slopes in central/northern Japan. During the 2018 breeding season, we investigated the density and habitat selection of Skylarks on the volcanic slopes above timber line, of Mt. Tarumae, Hokkaido. Our results showed that there were 27 Skylark territories in the study area, with a density of 7.26 territories per square kilometer. This spatial arrangement was dense around the eastern slope. Skylarks favored habitats with a low vegetation height. The quantity of short plant species, i.e. Carex oxyandra and Arcterica nana was larger in territories than in randomly selected points. C. oxyandra plays important roles not only in forming low vegetation, but also in available and limited nest material in their breeding territories on the volcanic slopes. These results suggest that Skylarks occupy areas of low vegetation with C. oxyandra, as there are limited resources available for nest materials within the breeding territories that are on the volcanic slope above a timber line.

Reconstruction of maximum temperature on Zhegu Mountain, western Sichuan Plateau (China)

Historical temperature reconstructions at high altitudes are still insufficient in southwestern China, which is considered one of the most sensitive areas to climate change in the world. Here we developed a tree ring-width chronology of Faxon firAbies fargesiivar.faxonianaat the upper timber line on Zhegu Mountain, Miyaluo Scenic Area, western Sichuan, China. The climate-tree growth relationship analysis indicated temperature as the dominant regulator on radial tree growth in this region. The reconstruction of aggregated maximum temperature (TMX) of autumn and winter for the period 1856-2016 was achieved with a linear regression model that accounted for 43.6% of the actual variability in the common time series (1954-2016). The reconstruction identified 4 warm periods and 3 cold periods. Similarities of warm and cold periods with previously published reconstructions from nearby sites indicated the reliability of our reconstruction. The significant positive correlation between TMX reconstruction and the Asian-Pacific Oscillation index and the Atlantic Multi-decadal Oscillation index suggested a linkage between large-scale climate circulations and the thermal variability at a multi-decadal scale on the western Sichuan Plateau. We also found that solar activity exerted a strong influence on decadal temperature variability in this region. The cold periods were matched well with historical large volcanic eruptions. Our results strengthen the historical climatic information in southwestern China and contribute to further understanding the regional thermal variability as well as its driving mechanism.

Pakistan�s Timberline Forest Ecosystem Dynamics vis-a-vis Changing Climate Across Three Provinces (KPK, AJK and GB) Using GIS/RS Techniques

World`s forests have always been under anthropogenic threats leading to instantaneous and sound supervision using satellite-based data collecting capabilities through GIS/RS. Timber line in Pakistan consists of sub-alpine forests and alpine pastures of KPK, AJK and GB. Research findings showed that earth`s climate was changing rapidly than previously assumed, demanding the spatio-temporal dynamics analysis using GIS/RS techniques in prevalent climate change scenarios. Two separate methods were used; 1) Visual Interpretation of Supervised Classification Technique for AJK & GB and 2) object Oriented Classification of Supervised Classification Technique for KPK. The primary data for T (max), T (min) & Ppt. (1980-2013) was taken from PMD, Islamabad. Province wise data showed 15 % change in forest cover area for timber line in both KPK (142780 Ha) & AJK (24990 Ha), followed by GB (39267 Ha) as13 % across 2005-2014. The results calculated that the average upward shift in timberline was highest in KPK (285 m), followed by AJK (233 m) and GB (170m) across 2005-2014.The data also showed change in avg. T (max) was 3.4�, -1.8� and 0.6� C, avg. T (min) was -2�, -1.5� and -2� C while change in total precipitation was 88.5, -3.7 and 75.5 mm for AJK, GB and KPK respectively. The Pearson`s Correlation Co-efficient chart concluded that climatic factors showed a strong and positive correlation among themselves as well as with change in elevation. However, the correlation among climatic factors and change in forest cover area was weak concluding deforestation to be exclusively an anthropogenic phenomena. Change in elevation showed a weak and negative correlation with change in area while all other correlations were non-significant.

Tree ring–based minimum temperature reconstruction in the central Hengduan Mountains, China

We developed a tree ring-width chronology of Abies georgei at the timber line in the Big Snow Mountain Scenic Area in northwestern Yunnan, China. The climate-tree growth response analysis indicated that temperature was the predominant regulator of A. georgei growth in this region. An annual mean minimum temperature (AMMT) reconstruction spanning A.D. 1837–2016 was developed with a linear regression model (y = 1.0x − 6e − 5) that accounted for 50.7% of the actual temperature variance during the common period (1960–2016). Based on the reconstructed temperature series, the warmer periods were 1840–1845, 1855–1865, 1880–1895, 1945–1965, and from 1995 until the present day, and the cold periods were 1870–1880, 1900–1930, and 1966–1980. By comparing our results with other regional tree ring records from surrounding areas, a distinctive amount of common warm and cold periods were found, indicating the reliability of our temperature reconstruction and suggesting that the climate in the study area was part of a large-scale climate system.

Shifting of Vegetation and Timber Lines in Pinder Watershed Central Himalaya Using Geospatial Technology

Greenhouse gases are the most responsible for climate change due to global warming. The Himalayan region, which covers eight countries across Asia, is home to some of the world’s largest and most spectacular glaciers. In the Himalaya, large areas are covered by glaciers and seasonal snow. They are an important source of water for the Himalayan rivers. The Himalaya has been a perennial source of attraction, curiosity, and challenge to human intellect throughout the ages. Among several assets, the vegetation provides an everlasting and interesting field of investigation. The results of this study are highly relevant to glaciers in the central Himalaya, which exhibit some of the most rapid retreat rates on earth in recent decades. This paper is an attempt to examine the variations in vegetation line and timber line altitude using Normalized Difference Vegetation Index and Normalized Difference Snow Index in Pinder Watershed, Uttarakhand (India). Landsat satellite imageries of four decades (1990, 2001, 2011, and 2019) were used to quantify vegetation line and timber line altitude. In the last few decades, the impact of human activities as well as climatic impact in glacier has become more accelerated and pronounced. Heavy biotic pressures have started to exert tremendous stress on natural resources and hence many of the plant species are under various degree of threat. So, human beings need to be educated for understanding, solution, and preventing of these problems.

Discovery, Controls, and Hazards of Widespread Deep‐Seated Gravitational Slope Deformation in the Etsumi Mountains, Central Japan

AbstractDeep‐seated gravitational slope deformation (DSGSD) is a largely unnoticed but important long‐term mass wasting process that may result in catastrophic failure of mountain slopes. Manifested by small topographic irregularities such as ridge‐parallel scarps and linear depressions, it has been predominantly reported in alpine landscapes above timber lines. On the basis of area‐wide high‐resolution topographic data acquired by light detection and ranging (lidar) surveys, we here show that ~96% of existing gravitational scarps have been hidden under forest canopies in the Etsumi Mountains, central Japan. The scarps are surprisingly widespread over the mountains with a mean line density of as large as 0.87 km/km2. Our analyses of the scarp distribution suggest that uphill‐facing scarps are primary geomorphic signals of DSGSD with a destabilized rock mass larger than ~105 m2, whereas downhill‐facing scarps principally occur in response to more localized slope deformation. In terms of controls, topography is by far the most influential factor in triggering and promoting DSGSD. Despite theM7.5 earthquake in 1891, impact of large local earthquakes proves to be not very strong. Comparison with preexisting landslide maps further suggests that DSGSD and large‐scale landslides are not different slope processes but represent different stages of the same process. Our results highlight limitations of aerial‐photograph interpretation in forest‐covered mountains and the need for lidar‐assisted mapping for deeper understanding of this long‐term process and interactions between surface and tectonic processes.

A new species in the Simulium vernum group from the Alps of southern Germany: Simulium arminii (Diptera: Simuliidae).

Simulium arminii new species is described from the Alps of southern Germany. It is characterized by a broad trapezoidal ventral plate in the male, long slender arms of the genital fork in the female, a weakly developed or absent anterodorsal projection on the thinly woven cocoon, and a long median hypostomal tooth in the larva. The species is chromosomally similar to Simulium beltukovae (Rubtsov) but differs most conspicuously by the absence of a chromocenter. It is known from two small, springfed streams above the timber line, in association with Prosimulium latimucro (Enderlein) and Simulium bavaricum Seitz and Adler.

Ozone phytotoxicity in the Western Carpathian Mountains in Slovakia

Abstract In this work, the response of temperate coniferous forests to ozone air pollution (O3) in the mountain environment of the High Tatra Mts. (Western Carpathians) was analyzed. The modelling of stomatal O3 flux is a complex method for the estimation of phytotoxicity of O3 pollution to forest vegetation. Stomatal flux-based critical levels (CLef) for effects of O3 on radial growth take into account the varying influences of O3 concentration, meteorological variables, soil properties, and phenology. The application of the model DO3SE (Deposition of Ozone for Stomatal Exchange) at five experimental plots with altitudes varying from 810 to 1,778 m a.s.l. along vertical and spatial profile in the High Tatra Mts. revealed the high phytotoxic potential of O3 on spruce forests during the growing season 2014. The accumulated stomatal O3 flux above a threshold of Y (1 nmol m−2 s−1), i.e. POD1 (Phytotoxic Ozone Dose) ranged from 13.6 mmol m−2 at the Kolové pleso site (1,570 m a.s.l.) to 16.2 mmol m−2 at Skalnaté Pleso site (1,778 m a.s.l.). CLef for POD1 (8 mmol m−2) recommended for the protection of spruce forests were exceeded at all experimental plots from early July. Similarly, AOT40 index suggests vulnerability of mountain forests to O3 pollution. AOT40 values increased with altitude and reached values varying from 6.2 ppm h in Stará Lesná (810 m a.s.l.) to 10.7 ppm h at Skalnaté Pleso close to the timber line (1,778 m a.s.l.). Concentration-based critical level (CLec) of 5,000 ppb h was exceeded from June to August and was different for each experimental site.

The seasonal trade-off between food and cover in the Alpine mountain hare (Lepus timidus)

Habitat use of prey species is often subjected to strong trade-offs when foraging needs and predator avoidance cannot be met simultaneously. Trade-offs may be particularly pronounced for species dwelling above ground throughout the year. Identifying habitat use of such species may help to determine crucial and limited environmental resources and has strong implications for habitat management. We investigated the relative importance of habitat structure and composition for mountain hares in the Swiss Alps at the small scale for two time periods, throughout the year and during the reproductive period. Habitat use was assessed by a non-invasive approach that considers the spatio-temporal distribution of fecal pellets, sampled along systematically distributed transects. We found that heterogeneous habitats with high diversity of vegetation layers and/or abundance of saplings and storeyed vegetation structures are strongly used. The availability of shelter was more important in summer when hares strongly used dense habitats that offered protection from predators. The availability of food was more important as predictor for year-round use compared to the reproductive period when food is overabundant for hares. A heterogeneous habitat provides an optimal distribution and availability of shelter and food resources and allows the hare to adjust its activity pattern to changing environmental conditions. Therefore, the occurrence of a structurally heterogeneous ecotone at the upper timber line with a mosaic of different vegetation types and hiding structures should be considered in the management of the species.

Mensularia rhododendri (Hymenochaetaceae, Basidiomycota) from southwestern China

A new species Mensularia rhododendri is described from southwestern China on the basis of both morphological characters and molecular evidence. Phylogenetic analysis based on nuclear large subunit (nLSU) ribosomal RNA gene shows that the new species belongs to Mensularia. Morphologically, the new species is mostly similar to Mensularia hastifera by sharing similar hymenial setae and basidiospores in shape and size. However, M. rhododendri differs in smaller pores (5–6 per mm), thinner fruit body (up to 2.5 mm), shorter and unbranched hyphoid setae (up to 110 µm long) present in trama only, basidiospores not collapsed, and growth on Rhododendron in nearly the timber line of southwest China, while M. hastifera has relatively larger pores (3–4 per mm), thicker fruit body (up to 10 mm), longer and sometimes branched hyphoid setae (up to 300 µm long) frequently present in both trama and dissepiments, and mostly collapsed basidiospores, and occurs mostly on Fagus in the temperate area of Central Europe. The morphological differences between M. rhododendri and other similar species of Mensularia are also compared.

Ландшафтний метод у дослідженні верхньої межі лісу

Analyzed and generalized is a short historiography of the problem. Considered scientific approaches in the study of the forest timber-line. Showed the benefits of landscape approach in the study of the forest timber-line. The leading role is given to factors lithogenic group due to their stability and inertness. In most cases, geological structure and topography influence on the formation of the forest timber-line satisfactory, affecting the nature and speed of the wind, the temperature increase of the show up, insolation, flow regime of surface and groundwater, etc. Highlighted two types and subtypes offorest timber-line in the Ukrainian Carpathians. Key words: forest timber- line (TL), polonynas, highland.

Aboveground Biomass Carbon in the Alpine and Arctic Treeline Ecotones in the Ural Region

This paper reports on measured carbon stocks in the forests of two treeline ecotones of the Ural region where climate change might improve growing conditions. The first is an alpine ecotone that is represented by an altitudinal gradient of the spruce-dominated forests on the Western slope of the Tylaiskii Kamen Mountain (Western part of the Konzhakovskii-Tylaiskii-Serebryanskii Mountain system, 59030'N, 59000'E), at the alpine timber line that has risen from 864 to 960 m above sea level in the course of the last 100 years. The second is an arctic ecotone in larch-dominated forests at the lower course of the Pur River (670N, 780E), at the transition zone between closed floodplain forests and open or island-like communities of upland forests on tundra permafrost. According to our results, there are large differences in the carbon of the aboveground biomass of both ecotones across environmental gradients. In the alpine treeline ecotone, a 19-fold drop of the carbon stocks was detected between the lower and higher altitudinal levels. In the arctic ecotone the aboveground biomass carbon stock of forests of similar densities (1300 to 1700 trees per ha) was 7 times as much in the river flood bed, and 5 times as much in mature, dense forests as the low density forests at higher elevations.

Верхня межа лісу в ландшафтах Українських Карпат, її охорона та оптимізація

Forest timberline (TL) is a compound and dynamic organism, whish is situated on the boundary of the forest zone and the highland. The study embraces regions of the Ukrainian Carpathians. In the Carpathians are determined 2 types of TL: natural and anthropogenic. Subtypes of natural TL: thermal, orographical, winddepen, avalanche depend, biotic, peat- swamp, gregot, talus trail. It was defined 2 options of TL: firry and beechy. Key words: The Ukrainian Carpathians, forest timber – line (TL), polonynas, highland.

Ground beetles (coleoptera, carabidae) of the Ola Plateau highlands, Kolyma Uplands

The ground beetle fauna was studied in 12 biotopes of the tundra belt on Ola Plateau, 130 km NW of Magadan. In all, 16 species were found above timber line (900–1220 m), which is comparable with the diversity in the mountain tundras of the upper reaches of the Kolyma (Berman et al., 1984; Bukhkalo, 1997), but the faunistic similarity of these regions is low (Jaccard’s coefficient 22–29%). Besides the widespread species, a group of ground beetles with limited ranges is present; it includes Carabus kolymensis Lafer, 1989 occurring in the East Siberian mountain tundras, the Siberian-Nearctic, mainly arctic Pterostichus agonus G. Horn, 1880, and the East Siberian Pterostichus eximius A. Mor., 1862. The use of the term “arctic species” in arealogical and ecological studies is discussed.