Search

The intertwining of agriculture and economic development during Morocco's period of French colonialism holds a fascinating historical significance. This paper attempts into how this relationship shaped the local characteristics of Morocco's economy, offering insights into the complex dynamics of colonial influence on agricultural practices and their impact on the nation's economic trajectory. This research aims to investigate the agriculture and economic development of the Ait Werra tribe during the French protectorate in Morocco. The French protectorate, established on March 30, 1912, brought about various changes in the agricultural and economic policies of Morocco in the first half of the twentieth century. These changes affected both urban and rural areas, but the tribal economy experienced the most significant impact. While the cities had already opened up to European countries and welcomed their traders, the Moroccan villages remained isolated from the outside world, and the authority of the Makhzen was not prevalent in many mountain tribes. Thus, colonization was a massive shock that transformed all aspects of life, especially for tribes like Ait Werra, which is a part of the Berber confederation and situated in the Middle Atlas Mountain range near to El Kssiba. This article will explore the fixations and transformations of the Ait Werra tribe's economy as it transitioned from the pre-Makhzen to post-colonial era in Morocco. [ABSTRACT FROM AUTHOR]

Permafrost is a sub-ground phenomenon and therefore cannot be directly observed from space. It is an Essential Climate Variable and associated with climate tipping points. Multi-annual time series of permafrost ground temperatures can be, however, derived through modelling of the heat transfer between atmosphere and ground using landsurface temperature, snow- and landcover observations from space. Results show that the northern hemisphere permafrost ground temperatures have increased on average by about one degree Celsius since 2000. This is in line with trends of permafrost proxies observable from space: surface water extent has been decreasing across the Arctic; the landsurface is subsiding continuously in some regions indicating ground ice melt; hot summers triggered increased subsidence as well as thaw slumps; rock glaciers are accelerating in some mountain regions. The applicability of satellite data for permafrost proxy monitoring has been demonstrated mostly on a local to regional scale only. There is still a lack of consistency of acquisitions and of very high spatial resolution observations. Both are needed for implementation of circumpolar monitoring of lowland permafrost. In order to quantify the impacts of permafrost thaw on the carbon cycle, advancement in wetland and atmospheric greenhouse gas concentration monitoring from space is needed. [ABSTRACT FROM AUTHOR]

At present, there is an increasing pressure to reduce the chemical load in plant-based foods, a situation especially driven by European consumers, so it is urgent to develop clean production practices such as the use of organic fertilizers in crop production. The present study aimed to determine the effect of the edaphic dose of earthworm humus and water hyacinth in bell pepper production used as organic fertilizers. The research was carried out at the Experimental Center "La Playita", Technical University of Cotopaxi, La Maná Extension, located at 120 m above sea level. Two organic fertilizers were evaluated in doses of 1.0; 2.5; 3.0; 5.0; 6.0; 7.5 and 8.0 kg-m-² established in a randomized block design. The variables evaluated were: plant height (cm), number of fruits and fruit biomass (g), recorded during six years. The result of the 5 and 8 kg-m-² dosages allowed a better development and production of the pimento crop with organic fertilizer, water hyacinth. In conclusion, it is necessary to nourish a soil based on the soil and compost analysis where the exact dosage of organic matter required by a soil can be rescued. in urban-marginal and rural areas of the province of Guayas (Ecuador). By means of an applied study with a qualitative, quantitative, field, descriptive-prospective-analytical-transversal approach, fecal samples of humans and their domestic dogs from the indicated areas will be analyzed, in order to know: The relationship between the environment-helminths-and hosts, prevalence of neglected intestinal helminthiases, zoonotic association, characterization of environmental variables, specification of social determinants of health and generate scientific production. [ABSTRACT FROM AUTHOR]

Aim: Most biodiversity studies have considered species to be isolated entities, neglecting the fact that their biotic interactions and spatial variation are fundamental to their persistence across elevational gradients. Here, using a standardized sampling methodology, we evaluated how and why the composition of flower–visitor interactions (i.e. beta diversity) varies over an extensive elevational gradient. Specifically, we aimed to identify which biotic (species turnover) and abiotic factors (temperature, precipitation and primary productivity) inherent to elevational gradients can explain the distribution of floral visitor–plant interactions. Location: Mexican Transition Zone. Taxon: Angiosperms, Hymenoptera, Lepidoptera, Diptera, Hemiptera and Coleoptera. Methods: We sampled ecological interactions between floral visitors and flowering plants at 10 sites along an elevational gradient from 4 to 3425 m.a.s.l. We measured the additive partitioning of the beta diversity of species interactions and used generalized dissimilarity modelling to assess how spatial and environmental factors can explain the observed dissimilarity. Results: We found that the composition of interactions between floral visitors and plant species differs from lowlands to highlands mainly due to differences in temperature across the studied elevation gradient, rather than geographical distance or other environmental factors (i.e. mean annual precipitation and net primary productivity). We also observed that the main component of the beta diversity of interactions was interaction turnover driven by the turnover of both plants and floral visitors along the elevation gradient studied, which may be influenced by both temperature and the biogeographical affinity of biotas. Main Conclusions: We conclude that environmental filters play a crucial role in the establishment of novel interactions, as temperature can filter species and impact the behaviour and traits of floral visitors and plants across an elevational gradient. These findings underscore the importance of considering the role of abiotic factors in predicting and explaining the distribution of species interactions across different elevational gradients. [ABSTRACT FROM AUTHOR]

Tropical cyclones (TCs) making landfall in Luzon weaken due to the surface friction of Luzon's mountainous terrain and the reduced ocean heat, momentum, and moisture fluxes over the landmass. Landmass also influences TC rain distribution by orographic enhancement or blocking of a TC's moisture-laden circulation. In this study, we investigated the influence of the effects of the Sierra Madre and the Cordillera Mountains Ranges (SMMR and CMR) on TC-associated wind and rainfall hazards to answer the question of whether the SMMR or the CMR mitigates TC hazards. We used the Weather Research and Forecasting (WRF) model with modified SMMR and CMR terrains to disentangle the effects of the orography with flat land. Results show that Luzon-passing TCs maintain their intensities at landfall regardless of the frictional effects of the mountain ranges, but the CMR inhibits the re-intensification of westward-moving TCs emerging from landmass after traversing Luzon. The SMMR reduces wind exposure and basin-wide rainfall of the Cagayan Valley. Hence, the SMMR can be considered a barrier for that region. In addition, the weakening effect of the SMMR reduces the wind exposure of the island of Catanduanes and eastern Bicol the most. However, for the rest of Luzon, the SMMR enhances rainfall, which will likely compensate for the slight decrease in wind exposure - especially considering that most TC-related damages are water/rainfall related. The CMR, overall, has a larger hazard-mitigating effect than the SMMR. In any case, we believe that shifting the discourse to these mountains' biodiversity conservation and restoration - rather than their purported TC mitigating effects - will be more strategically constructive. [ABSTRACT FROM AUTHOR]

Informatization is an important trend in the field of mountain highway management, and the digital twin is an effective way to promote mountain highway information management due to the complex and diverse terrain of mountainous areas, the high complexity of mountainous road scene modeling and low visualisation efficiency. It is challenging to construct the digital twin scenarios efficiently for mountain highways. To solve this problem, this article proposes a knowledge-guided fusion expression method for digital twin scenes of mountain highways. First, we explore the expression features and interrelationships of mountain highway scenes to establish the knowledge graph of mountain highway scenes. Second, by utilizing scene knowledge to construct spatial semantic constraint rules, we achieve efficient fusion modeling of basic geographic scenes and dynamic and static ancillary facilities, thereby reducing the complexity of scene modeling. Finally, a multi-level visualisation publishing scheme is established to improve the efficiency of scene visualisation. On this basis, a prototype system is developed, and case experimental analysis is conducted to validate the research. The results of the experiment indicate that the suggested method can accomplish the fusion modelling of mountain highway scenes through knowledge guidance and semantic constraints. Moreover, the construction time for the model fusion is less than 5.7 ms; meanwhile, the dynamic drawing efficiency of the scene is maintained above 60 FPS. Thus, the construction of twinned scenes can be achieved quickly and efficiently, the effect of replicating reality with virtuality is accomplished, and the informatisation management capacity of mountain highways is enhanced. [ABSTRACT FROM AUTHOR]

Water temperature is recognized as an important driver of aquatic ecosystems and is of increasing interest because of global warming. However, to date, no studies have disentangled the contribution of annual thermal variability from the contributions of annual thermal mean and other environmental variables to spatiotemporal patterns of macroinvertebrate assemblages in mountain streams. In this study, we explored patterns of macroinvertebrate biodiversity within and among 5 mountain stream sites in the Serio watershed (Orobic Alps, Northern Italy) along a gradient of annual water thermal variability (annual range: ~1–16°C) but with similar means. At each site, macroinvertebrates were sampled; physicochemical variables, flood disturbance, and resource availability were measured monthly over a year; and water temperature was monitored continuously. The relationship between macroinvertebrate assemblages and environmental conditions was described by separating time and space through co-inertia analyses. Results showed a strong temporal co-inertia, with floods and mean monthly temperature most associated with within-site macroinvertebrate temporal patterns (70% of total variance) and with the greatest effects on the abundance of stoneflies. Synchronous floods occurred in all sites and promoted changes in macroinvertebrate community composition through a loss of taxa and individuals, whereas monthly water temperature variations were associated with the replacement of individuals among taxa. Spatial differences (30% of the total variance) were mainly linked to geographical proximity, although annual thermal variability covaried with annual temporal dissimilarity in taxonomic composition, suggesting that temporal patterns also explain spatial differences. Overall, the study indicates that even when accounting for the overall environmental setting, the thermal regime remains an important driver of macroinvertebrate spatiotemporal patterns. Mountain streams are particularly subject to thermal variation, and an increase in mean water temperature and thermal variability will substantially influence community composition, with the strongest effects on cold stenothermal taxa. Large-scale research across mountain ranges is essential to properly assess how spatiotemporal thermal heterogeneity influences the distribution of macroinvertebrates, as well as to guide conservation strategies in the context of increasing global warming. [ABSTRACT FROM AUTHOR]

Ancient Chinese civilization was deeply rooted in a profound understanding of the environment. This understanding formed the primitive worship and unique culture of mountains and rivers, which found expression in both official and folk contexts. This essay delves into the significant influence of mountains and rivers on the site selection, positioning, and composition of ancient Chinese settlements. Through an in-depth analysis of cases, this study demonstrates that iconic mountain and river elements served as the foundation for determining the spatial locations of ancient Chinese settlements and the core references for designed landscapes. The settlement and surrounding mountains and rivers form a well-conceived integrated spatial composition, which threads the whole planning and construction process. As the determining factors for the spatial axes and forms of settlements, mountains and rivers also became the central objects of the feng shui theory. Therefore, the human geography of ancient China is not only a reflection of functions but also the result of the builders' diligent pursuit of spatial and cultural layouts. The study of the cultural genes allows for a deeper understanding of the cultural landscape of ancient China, leading to a commitment to protecting traditional settlements and their intact environmental systems. [ABSTRACT FROM AUTHOR]

In mountain regions, biological soil crusts (BSCs) provide essential ecological services by being involved in primary production and nitrogen fixation. Eukaryotic algae and cyanobacteria are important photosynthetic components of these unique cryptogamic communities. Here, we present an overview of the eukaryotic and prokaryotic diversity of such phototrophs in BSCs in the mountain tundra of the northern Ural Mountains. Such assessment is based on morphological surveys and the first metabarcoding analysis in the region. In total, 166 taxa of Cyanobacteria and 256 eukaryotic algae (including Euglenophyta, Ochrophyta, Dinophyta, Bacillariophyta, Chlorophyta, and Charophyta) were identified. For the first time, 86 taxa new to the BSCs of the high-mountain belt of the region were discovered. Considering species composition, Cyanobacteria and Chlorophyta are the most abundant taxa in all the analyzed BSCs. The genera Nostoc, Coccomyxa, Chlamydomonas, Leptolyngbya, Stenomitos, Pycnacronema, Stigonema, and Eunotia had the highest number of taxonomic units. These groups shape the structure, function, and ecology of the BSC communities in the studied region. Our results show that BSCs in the tundras of the Ural Mountains have a high active and passive biodiversity of terrestrial cyanobacteria and algae. Both implemented methods resulted in similar results with a comparable number of algae and cyanobacteria species per sample. Metabarcoding could be implemented in future in the region to accurately screen photosynthetic organisms in BSCs. [ABSTRACT FROM AUTHOR]

The article examines Döblin's novelistic treatment of geographical information with regard to China. By means of sketches and choice quotations, proof was found that Döblin not only adopted findings by Ferdinand Baron von Richthofen, but implicitly stressed the German geographer's intention to utilise China's large coal deposits for colonial interests. The example of the Nan‐ku mountains, where in the novel the political/religious movement of the 'Truly Weak' alliance first formed itself, serves to examine how Döblin makes use of geological and historical facts from von Richthofen's scientific studies. This reveals itself, for instance, in his only slightly differing description of the Nan‐ku mountain range from what von Richthofen had noted. In its attempted exactitude, the former notion can be considered a typical feat of literary Realism. We also further examine the crucial role this much sought‐after Chinese mineral wealth – coal – plays in the later rebellious upheaval. Our results contradict the current notion that Döblin depicted a historically divested, contrapuntal view of China as compared to the Western Hemisphere. Instead, the novel markedly deals with real geographical, social and political facts about China in the colonial era. A merely expressionist view on Döblin's novel does not seem to hold. [ABSTRACT FROM AUTHOR]

The main purpose of this research is to determine the thickness of the crust and lithosphere in the northeastern regions of the Iranian plateau. There are different methods to determine these two parameters. According to the definitions and how to determine this thickness, each of the methods has advantages and disadvantages. In this research, large-scale satellite data is used, so we do not need data acquisition that makes it a great advantage, and inversion in this way will give us the final model of the crustal and lithospheric structure in the shortest time. For this purpose, a joint inversion of geoid topography and gravity data is used. First, we obtain a 1D model that is close to reality using the simultaneous modeling of geoid data, topography, basic concepts of physics and mathematics and local isostasy, for the thickness of the Moho and lithosphere. Then we use a 3D inversion method to reduce the difference between the measured and calculated data. The initial model that is given to the program in 3D inversion is the output of 1D modeling. The studied area, the northeastern region of the Iranian plateau (including Kopeh-dagh) is an area with great potential in natural resources (mainly oil and gas). The highlands of northeastern Iran are formed in the Alpine-Himalayan folds and are similar to the Zagros mountains from a geological point of view. The Kopeh-dagh mountain range starts from the east of the Caspian Sea and enters Afghanistan after passing through Turkmenistan. The Kopeh-dagh mountain range separates the Turan plate from the central Iranian plate (a part of the Eurasian shield) and reaches a maximum height of 3000 meters. Most geologists consider Kupe-dagh to be the southern edge of the Turan shield and a part of the Eurasian plate. The main fault of Kopeh-dagh (Eshgabad) along the N130 direction forms the southern border of the Turan plate with the Kopedagh mountain range. A very small anomaly, the free-air gradient in the northeast of the Ashgabat fault, indicates the subduction of the southwest-trending Turkmenistan plate beneath Kupeh-dagh. In this way, less displacement is observed between the Turkmenistan plate and the southeastern Caspian lowlands compared to the displacement between the Turkmenistan and Iran plates that can be proved from the value of the gravity anomaly in the west. There are large gas fields shared by the three countries of Iran, Turkmenistan and Afghanistan in the Kopeh-dagh region and its surrounding areas. Huge gas fields in Iran, Daulatabad-Donmez, Ghazli, Shatlik, Mehri and Bayran Ali in Turkmenistan and Gogar in Afghanistan have been discovered in this area. Geographically, Kopeh-dagh is part of the eastern continuation of the Alborz Mountains, but its geological and structural features are different from the surrounding areas. One of the main goals in the exploration of oil resources is to describe the structure of the sedimentary cover and underground topography. Furthermore, oil production is very sensitive to heat storage by the source rock and thus to the tectonic evolution of the entire lithosphere. Results show that the thickening of the Moho is observed under the Kopeh-dagh mountain range and the thickness decreases gradually when moving towards the northeast and southwest of the Kopeh-dagh mountain range. The depth of the Moho in the studied area varies from 40 to 60 km. According to the modeling results, the lithosphere-asthenosphere boundary in the southwestern part of the studied area (Central Iran) is approximately 100 km, and it reaches approximately 200 km towards the northeast of the this area. [ABSTRACT FROM AUTHOR]

Appropriate nutritional preparation for a high-mountain expedition can contribute to the prevention of nutritional deficiencies affecting the deterioration of health and performance. The aim of the study was to analyze the dietary habits, supplementation and nutritional value of diets of high mountain climbers. The study group consisted of 28 men (average age 33.12 ± 5.96 years), taking part in summer mountaineering expeditions at an altitude above 3000 m above sea level, lasting at least 3 weeks. Food groups consumed with low frequency during the expedition include vegetables, fruits, eggs, milk and milk products, butter and cream, fish and meat. The energy demand of the study participants was 4559.5 ± 425 kcal, and the energy supply was 2776.8 ± 878 kcal. The participants provided 79.6 ± 18.5 g of protein (1.1 ± 0.3 g protein/kg bw), 374.0 ± 164.5 g of carbohydrates (5.3 ± 2.5 g/kg bw) and 110.7 ± 31.7 g of fat (1.6 ± 0.5 g/kg bw) in the diet. The climbers' diet was low in calories, the protein supply was too low, and the fat supply was too high. There is a need to develop nutritional and supplementation recommendations that would serve as guidelines for climbers, improving their well-being and exercise capacity in severe high-mountain conditions, which would take their individual taste preferences into account. [ABSTRACT FROM AUTHOR]

The emergence of human settlements has always been based on natural factors; Factors such as altitude, water resources, communication routes, slope, temperature, and rainfall are the natural etiologies affecting the distribution of human settlements, which of course, some of them play a more effective role in this regard. This study investigates the correlation between the chalcolithic sites of Sarfirouzabad plain and environmental factors according to natural criteria. Sarfirouzabad plain is one of the environs of Firouzabad district, located 35 km southeast of Kermanshah province, along the natural plain of Mahidasht. This plain is extended to the southern and southeastern parts of Mahidasht in terms of natural geography. Six natural variables as affective factors in the establishment of settlements include altitude, distance from rivers and roads, the extent and continuity of periods of the sites, and position in the plains or mountainsides being selected and have been analyzed by using statistical methods and Moran I regional area index by GIS. Exploratory spatial data analysis is a method for studying random and non-random spatial distribution patterns of these variables, and spatial autocorrelation is one of the most practical and substantial analytical tools for research on spatial data. The results show that the archaeological sites are formed in connection with each other in addition to environmental factors. The spatial distribution of the archaeological sites in the area of research is cluster type. Based on hotspot analyses, past humans may have chosen to settle in two regions, namely the plain floor and the southern margin of the Sarfirouzabad plain, to adapt to their environment. These two types of settlements are indicative of two lifestyles and livelihoods. [ABSTRACT FROM AUTHOR]

Return migration has become a recent trend in the mountain regions of Pakistan, primarily driven by a rise in economic opportunities. To understand the perception of return migrants about the economic opportunities available to them and to highlight the various challenges they face in the reintegration process, this study was conducted in the Hunza Valley of Gilgit-Baltistan. This study employed a mixed research approach where quantitative data were collected using field surveys from 153 return migrants while qualitative data were obtained through in-depth interviews with thirty return migrants. The study reveals that return migrants face difficulties in finding economic opportunities in their home regions due to insufficient support for new initiatives. The study highlights that return migrants possess diverse skills and untapped potential that can be utilized to revitalize the mountain economy, given appropriate support and policies. In this regard, governmental and non-governmental institutions play a crucial role in facilitating the reintegration process by offering assistance in areas such as tourism and entrepreneurship. This study recommends that by developing comprehensive reintegration policies, the government should effectively leverage the skills and potential of return migrants, thereby driving economic growth and development in rural mountain communities across Pakistan. [ABSTRACT FROM AUTHOR]

Mountains harbour a disproportionate amount of biodiversity that is explained by both biotic and abiotic factors. Understanding the ultimate factors that shape these gradients including the interaction between trophic levels is important to highlight management practices that may help maintain biodiversity. Here we report an experiment carried out in a Pyrenean valley where a transhumant cattle herd grazes every year subalpine grasslands in a 700 m altitudinal range (1300–2000 m). In 2018 we measured species richness and abundance of plants and two groups of herbivorous insects (butterflies and grasshoppers) in 20 plots, and then we established 10 exclusion plots to study the effect of grazing during 2019 and 2020. Our results show that there were differences among the relative weight of abiotic and biotic factors that shape biodiversity gradients. Overall, the elevation gradient strongly affected plant, butterfly and grasshopper richness, as well as insect abundances. Plant and butterfly richness's were correlated via a cascading trophic effect while the slope played a very important role for grasshoppers. Livestock exclusion had a negative effect on plant richness through rapid growth of grass species but there were almost no changes in insect community composition after two years. The intra-annual effects of grazing showed early grazing to be positive for butterflies flying later during the season, as seen for a subset of plots within a narrow altitudinal range. In grazed plots, butterfly richness and abundance increased over the summer when the herd moved to alpine environments and exceeded those of non-grazed plots, indicating that a traditional transhumance management system can help sustain biodiversity in subalpine grasslands as a type of extensive grazing. Implications for insect conservation. Traditional grazing by transhumance systems allows grasslands maintenance in subalpine areas, which helps sustain butterfly and grasshopper populations. [ABSTRACT FROM AUTHOR]

Copyright of Annuario di Antropologia is the property of Ledizioni-LediPublishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Mountains represent 'experiments by nature' that permit testing ecological theory. Using herbarium samples of 92 Rhododendron species collected between 800 and 4500 m a.sl. in the Himalaya-Hengduan Mountains region, SW China, we explored congeneric elevational trends in key plant traits at the among- and at the within-species level. We aimed at identifying the contributing factors to phenotypic trait expression across a climatic gradient, distinguishing effects in response to elevation from those due to phylogenetic relatedness, non-phylogenetic species effect, and within-species trait variability. We found that a substantial fraction of the trait variation (up to 88%) is deeply rooted in phylogeny, with species elevation also revealing a strong phylogenetic signal. While accounting for these phylogenetic influences, we still found consistent associations with elevation of anatomical (increasing leaf thickness and decreasing specific leaf area), morphological (decreasing plant and leaf size, annual length increment), physiological (less negative foliage δ13C signal), and reproductive traits (flower size largely conserved, while leaf size declines, hence relative investment in flowers increases). Our findings support a combined action of phylogenetic inertia and phenotypic adjustments of plants to life conditions at high elevation. Given that our samples come from one genus and a natural climatic gradient (rather than botanical gardens) with temperature the dominant variable, such patterns represent a robust and representative signature of the multiple causes of trait-environment associations in woody species. [ABSTRACT FROM AUTHOR]

The article focuses on prospector Edward L. Schieffelin who explored city of Tombstone, Arizona and discovered a bonanza silver strike in a desolate section of Arizona. It mentions Ed returned to Nevada and worked hard for the next year and a half trying to save money to return to Arizona to prospect. It also mentions Ed followed them through the mountains and lower desert regions between Camp Huachuca.

Introduction. The article attempts to localize Tamerlane’s campaigns of 1395–1396 in Central Ciscaucasia aimed to weaken the Golden Horde, eliminate chief forces of Tokhtamysh and his allies native to the region invaded. Goals. The study seeks to analyze and compare data from artefacts, written and phonic sources relating to Tamerlane’s campaigns in Central Ciscaucasia, clarify the roles once played therein by archaeological sites investigated across Stavropol Krai. Materials and methods. The paper focuses on artefacts, written and phonic sources. The former include ones contained in the occupation layer of Majar hillfort and bearing traces of the city’s demolition in the late 14th century CE, as well as those from two other sites of the Golden Horde era — Novopavlovka and Kochubeevskoe-1 settlements. The examined written sources are works by Arab, Persian and Western European authors, including modern ones. As for medieval Arab and Persian sources, the most detailed accounts for further analysis are contained in Books of Victory by Nizam al-Din Shami and Sharaf al-Din ‘Ali Yazdi, as well as in chronicles by Abd-al-Razzāq Samarqandī. Most precious data has been discovered in J. Schiltberger’s writing, oral accounts summarized by E. Çelebi and A. Firkovich. The work employs the historical-systemic, historical-comparative, and cartographic methods. The analysis is supplemented with results of scientific surveys recently conducted across glaciers of the Central and West Caucasus. Results. In spring of 1395, Tamerlane invaded the East and Central Caucasus to defeat Tokhtamysh in the decisive battle that took place in the Malka-Kura interfluve. Later in autumn and winter of 1395–1396, the invaders would return to the North Caucasus for raids throughout the lands of Kuban and Beshtau. Conclusions. In 1395–1396, Tamerlane was following a certain plan of his compiled with due regard for natural/climatic conditions of the region and seasonal economic cycles of Central Ciscaucasia’s nomads. The invading troops kept the field with the use of local resources — foodstuffs of Dzhulat county, summer pastures of Bishdag, and winter pastures of the Kuma-Manych Depression. Tamerlane was devastating the right wing of the Ulus of Jochi to take into possession the resources previously deployed by rulers of the Golden Horde.

Alpine scrubs (Roso pendulinae-Pinetea mugo) and dwarf heaths (Loiseleurio procumbentis-Vaccinietea) are an exceptional assemblage of rich floristic units which contribute significantly to the overall diversity on the Balkan Peninsula. The main edificators of these types of habitats are mostly glacial relicts. Additionally, they are of the arctic, alpine, and boreal distribution types, which further emphasises their importance from the conservation point of view. We investigated their taxonomic richness, endemism, patterns of spatial distribution and diversification in the central Balkans as well as their coenotic composition using a comprehensive dataset (15,609 species occurrence data). The analyses were conducted at three hierarchical levels taking into account the ecological and geographic diversity of the alpine scrubs and dwarf heaths in the study area. The results obtained showed that in the alpine scrubs and dwarf heaths of the central Balkans 902 taxa (829 species and 73 subspecies) had been recorded, and that the proportion of endemics in these habitats is extremely high (ca. 22%). Our results further showed that in 180 randomly selected plots of medium size (≥ 10 and < 100 m2 ), the registered regional floristic richness for the unique sample size was 527 species, placing the alpine region of the Balkan Peninsula in second place among the richest alpine regions in the world. Moreover, significant regional differences in species composition were observed within the research area, with floristic richness and diversity increasing from north to south.

Alexander von Humboldt and Aimé Bonpland in their Essay on the Geography of Plants discuss what was known in 1807 about the elevational limits of vascular plants in the Andes, North America, and the European Alps and suggest what factors might influence these upper elevational limits. Here, in light of current knowledge and techniques, I consider which species are thought to be the highest vascular plants in twenty mountain areas and two polar regions on Earth. I review how one can try to compare elevational limits in different parts of Earth. I discuss recent advances in high-elevation plant ecology that would surely have fascinated von Humboldt such as the special snow-roots in some snow-bed plants and the coldest place on Earth where a vascular plant is growing. I briefly outline an ignored von Humboldt legacy, Mendelssohn’s Humboldt Cantata. In conclusion I summarise the foundations and legacies that von Humboldt created for global high-elevation ecology and biogeography.

Elevational gradients impact organisms in diverse ways because of lower temperatures and oxygen levels at higher elevations. Birds adapt to these constraints through changes in body size, plumage, metabolism, and behaviors such as elevational migration. But whether species show variation across multiple axes of adaptations along a single elevational gradient is not well demonstrated in the literature. The broad elevational distribution of the House Sparrow Passer domesticus in the Himalayas provides a rare insight into whether morphological and plumage modifications can simultaneously arise within a species across its elevational distribution. Drawing insights from eco-physiological patterns, we hypothesized that sparrows at higher elevations would exhibit larger body sizes (Bergmann’s rule), shorter extremities (Allen’s rule), and a more insulative feather structure. We sampled sparrows at 13 sites (n = 169) from 300 m to 3500 m along an elevational gradient in the western Himalayas and found that sparrows at higher elevations were significantly larger following Bergmann’s rule, and had more downy dorsal feathers likely giving higher-elevation sparrows thermal advantages at low temperatures. We show that House Sparrows may show convergent modifications in response to temperature clines whether they are elevational or latitudinal.

The intermittency of gravity wave potential energy (GWPE) in the upper troposphere and stratosphere was investigated using the Constellation Observing System for Meteorology, Ionosphere, and Climate-2 (COSMIC-2) temperature data over three typical mountains (Tibetan Plateau, Rocky Mountains, and Andes). These typical mountains have high sea level elevations but different land–sea contrast. The probability density function (PDF) of GWPE has the independent variable of GWPE and dependent variable of occurrence probability of GWPE over a region. Our analysis showed that the PDFs of GWPE over these three mountains roughly followed lognormal distributions in all heights and months. But, the key parameters (mean value and standard deviation) of lognormal distribution varied with heights and months. Above each mountain, the two key parameters exhibited similar temporal and spatial distributions. They had the largest values around the tropopause region, smaller values in the lower stratosphere (~20–30 km), and larger values in the upper stratosphere (~35–45 km). The intermittency of GWs is represented as the ratio of the GWPE at 50th percentile to the GWPE at 90th percentile. The weakest intermittency was at ~20–30 km (above the zonal mean winds of zero) over the Tibetan Plateau and Rocky Mountains in all months and over the Andes from November to March, respectively. Generally, the weakest intermittency (~0.4) occurred in the region where the key parameters were the smallest around summer. The key parameters of lognormal distribution were dominated by annual variation over the Andes throughout the height range, 8–50 km. However, the semiannual variations are also significant in the lower stratosphere over the Tibetan Plateau and Rocky Mountains. The seasonal variations in the intermittency were not as obvious as those of the key parameters. The lognormal distributions and the intermittencies derived here provide an observational constraint on the tunable parameters in GW parameterization schemes.

The article focuses on Hamlin Garland, novelist and prominent man of letters, enthusiastically boarded a train in Chicago for Colorado Springs and the refreshing Rocky Mountains. It mentions Englishmen raised polo ponies and maintained a polo field and volunteered to accompany him on a camping trip into the remote mountains. It also mentions mountain sheep hunting and their alleged discovery of a lost mine and lived high in the mountains.

In this autoethnography, I read my history of and connection to outdoor culture, with an eye toward interrogating my complicity in historical and ongoing settler-colonial violence that has rendered my love of "the mountains" both possible and ostensibly unproblematic. In so doing, I unsettle (my) understandings of the connections between land, embodiment, masculinities, and able-bodiedness, exploring how settler attachment to the mountains is predicated on and serves to perpetuate, a(n ongoing) history of land dispossession. I also, however, consider a "different temporal horizon" through a discussion of settler futurity as it relates to outdoor recreation, complicating settler mobility in the process. [ABSTRACT FROM AUTHOR]

Changes in hydrothermal conditions have significant effects on vegetation, but there is still a lack of understanding of how vegetation responds to land surface (surface temperature and soil moisture) and meteorological (temperature and precipitation) conditions in mountain regions. This study examined the trends of leaf area index (LAI) in the Yan Mountains over the last four decades using Global Land Surface Satellite (GLASS) data. The results showed a persistent increase of LAI (greening) over 20 % to 80 % of the study area in growing season, spring, summer and autumn. Anthropogenic activities caused the greening trend by crop management before 2000 and afforestation after 2000. The increasing rate of LAI varied with elevation, and the most significant increase occurred in areas between 300 and 900 m, and the lowest increase occurred in areas below 300 m. Moreover, we found that LAI was negatively correlated with land surface temperature and soil moisture, but positively correlated with precipitation and air temperature. The time-lag effect was found between hydrothermal factors and LAI in the past four decades. There was a time lag of 2–3 months between LAI changes and temperature/precipitation during the early and late stages of the growing season, and a time lag of 0–1 month during the middle stage. Specifically, there was no time lag in vegetation response to surface soil moisture, and a time lag of 2–3 months in vegetation response to land surface temperature from July to October. Our findings provide insights into how vegetation adapts to land surface and climatic hydrothermal conditions in mountain regions and can be used by governments to develop policies for ecological protection.

The climatic changes that took place in Europe during the Quaternary period influenced plant habitats as well as their species and vegetation composition. In this article, biogeographical studies on Hercynian mountain plants that include data for the Alps, Carpathians, and European lowlands are reviewed in order to discuss the phylogeographical structure and divergence of the Hercynian populations from those in other European mountain ranges, Scandinavia, and lowlands. The analyzed studies show specific phylogeographical relations between the Hercynian mountains, Alps, Scandinavia, Carpathians, and European lowlands. The results also indicate that the genetic patterns of plant populations in the Hercynian Mountains may differ significantly in terms of origin. The main migration routes of species to the Hercynian ranges began in the Alps or Carpathians. Some species, such as Rubus chamaemorus L., Salix lapponum L., and Salix herbacea L., are glacial relics that may have arrived and settled in the Hercynian Mountains during the Ice Age and that survived in isolated habitats. The Hercynian Mountains are composed of various smaller mountain ranges and are a crossroads of migration routes from different parts of Europe; thus, intensive hybridization has occurred between the plant populations therein, which is indicated by the presence of several divergent genetic lines. [ABSTRACT FROM AUTHOR]

Background Euphorbia resinifera is a melliferous, medicinal, and endemic plant to Morocco. Nevertheless, its ecological and genetic diversity still unknown. The objective of this study is to analyze the diversity and genetic structure of Moroccan wild populations of E. resinifera using ISSR markers. Twelve natural populations collected from its geographical range in Morocco were analyzed using 14 ISSR primers. Results A total of 125 bands were obtained, with polymorphism of 74.81%. The polymorphic information content (PIC), resolving power (Rp), Shannon's information index (I), and total genetic diversity (Ht) were 0.33, 2.8, 0.35, and 0.21, respectively. The analysis of molecular variance showed that 75.56% of the total variability is present within populations and that 24.44% exists among populations. Also, the analysis showed a very low genetic differentiation between groups of mountain range type (FCT = 0.066), mountain versant type groups (FCT = -0.024), and altitude groups (FCT = -0.022). Moreover, the geographical distances between populations are correlated with their corresponding genetic distances according to the Mantel test (r = 0.507; P < 0.0001). Conclusion These results suggest that the population structuring follows a model of isolation by geographical distance. Indeed, the genetic structuring of populations into two groups obtained from PCoA and structure analysis revealed a dependence on the geographical origin of the populations. By contrast, the genetic distances are not correlated with the altitude. [ABSTRACT FROM AUTHOR]

Hypoxia can correct the development of diabetes and its complications in animals and humans, and diabetes exacerbates the gastric ulceration. However, the effect of hypoxia on the gastric ulceration in diabetes remains unknown. The task of the work was to compare the effect of keeping rats in the mountains under moderate natural hypoxia and on the plains on the development of type 1 diabetes and the gastric ulceration. Two weeks after the rats acclimatized to hypoxia (Elbrus region, 2125 m above sea level), they were injected with streptozotocin (STR, 50 or 70 mg/kg) or its vehicle. Simultaneously, rats on the plains were injected with STR (or its vehicle) at the same doses. Indomethacin (IM, 35 mg/kg) was administered two weeks after STR or its vehicle injection in rats after 24 h of starvation, both in the mountains and on the plains, which led to the gastric erosion formation 4 h later. The injection of STR (50 and 70 mg/kg) caused a dose-dependent increase in blood glucose levels in rats both in the mountains and on the plains, which indicates the development of diabetes of varying severity. In rats on the plains the administration of STR (50 and 70 mg/kg) led to a dose-dependent increase in the area of erosions induced by IM compared with those in control animals (STR vehicle). In rats in the mountains, an aggravation of gastric mucosal injury caused by IM was observed, both in control rats (STR vehicle) and in animals with STR-induced diabetes, compared with the gastric injury in rats of the corresponding groups on the plains. The greatest increase in the proulcerogenic effect of STR in the mountains was observed when it was administered at a dose of 70 mg/kg. Thus, persistent moderate hypoxia may lead to an increase in IM-induced gastric ulceration in rats with type 1 diabetes, and, in addition, by itself exacerbate the ulcerogenic effect of IM. [ABSTRACT FROM AUTHOR]

Sustainable landscape management is a key aspect for the development of mountain areas, especially where communities historically held common lands. Mountains face depopulation and abandonment, and transition to multifunctional landscapes emerges as an opportunity. We present a village case study (NW Portugal) focusing on people's perceptions and practices around the common land. Results confirm the common plays a central role in local identity, being perceived as shared heritage with potential to provide multiple benefits. Traditional uses and governance practices are prevalent, revealing inertia in adapting to new users and goals. Public support targeting common land management skills would facilitate these transitions, as well as to overcome lasting effects of former authoritarian regime. [ABSTRACT FROM AUTHOR]

Aim: Climate change is transforming mountain summit plant communities worldwide, but we know little about such changes in the High Andes. Understanding large‐scale patterns of vegetation changes across the Andes, and the factors driving these changes, is fundamental to predicting the effects of global warming. We assessed trends in vegetation cover, species richness (SR) and community‐level thermal niches (CTN) and tested whether they are explained by summits' climatic conditions and soil temperature trends. Location: High Andes. Time period: Between 2011/2012 and 2017/2019. Major taxa studied: Vascular plants. Methods: Using permanent vegetation plots placed on 45 mountain summits and soil temperature loggers situated along a ~6800 km N‐S gradient, we measured species and their relative percentage cover and estimated CTN in two surveys (intervals between 5 and 8 years). We then estimated the annual rate of changes for the three variables and used generalized linear models to assess their relationship with annual precipitation, the minimum air temperatures of each summit and rates of change in the locally recorded soil temperatures. Results: Over time, there was an average loss of vegetation cover (mean = −0.26%/yr), and a gain in SR across summits (mean = 0.38 species m2/yr), but most summits had significant increases in SR and vegetation cover. Changes in SR were positively related to minimum air temperature and soil temperature rate of change. Most plant communities experienced shifts in their composition by including greater abundances of species with broader thermal niches and higher optima. However, the measured changes in soil temperature did not explain the observed changes in CTN. Main conclusions: High Andean vegetation is changing in cover and SR and is shifting towards species with wider thermal niche breadths. The weak relationship with soil temperature trends could have resulted from the short study period that only marginally captures changes in vegetation through time. [ABSTRACT FROM AUTHOR]

Świętokrzyski National Park protects a low forested mountain range in SE Poland. Its bat fauna is understudied, with ten species listed from the area so far but with no knowledge of their reproductive status and distribution. We recorded 15 species, eight of them reproducing in the park. For seven species, the present study is the first record in the park. Among the netted bats, Myotis brandtii and Barbastella barbastellus were the most numerous. The ultrasound recordings were dominated by the small Myotis spp., with only a little share of Pipistrellus spp. We found predominance of Myotis mystacinus/brandtii/alcathoe complex and significantly male-skewed sex ratio, both features typical for the bat assemblages of the higher mountain ranges (e.g., Carpathians). Comparison of individual rarefaction curves with the two other Polish montane national parks revealed, however, much faster species accumulation due to the lower altitude and milder climate. Capture data suggest elevational gradient of bat species composition, with a shift in the structure of the bat assemblages around 330 m a.s.l., resulting in formation of two zones. These zones roughly correspond to the belt of lowland oak-hornbeam forests and montane beech and fir forests. However, no such pattern was revealed by the acoustic survey. [ABSTRACT FROM AUTHOR]

There are different ideas about the classification and distribution of permafrost in Mongolia. Terms such as continuous, discontinuous, sporadic, and isolated permafrost are inconsistently applied; hence, maps of permafrost display different distribution patterns. Particularly, the southern border of the Siberian permafrost in Mongolia is still debated. Furthermore, comparing these maps is challenging when studying impacts of climate change on permafrost. While, without a doubt, Mongolia's permafrost is in a stage of significant degradation and has receded from vast regions, telling this story is difficult when data are not easily comparable. Today, all permafrost is restricted to Mongolia's mountains. To better describe permafrost that depends on orography and elevation, we propose to use the more appropriate term 'mountain permafrost.' Surprisingly, the term 'periglacial' is mostly absent in the literature on Mongolia's permafrost. We here aim to clarify definitions of terms and hope that future studies will pay attention to both periglacial environments and mountain permafrost. [ABSTRACT FROM AUTHOR]

Copyright of Flora Montibérica is the property of Flora Montiberica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper presents ecological properties of plant species, occurring in the forest of the sessile oak and hornbeam community (Querco petraeae-Carpinetum betuli Rudski 1949. s.l.) in the area of Kosmaj in Serbia. The sessile oak and hornbeam forests in Serbia are conditioned by orographic and edaphic factors, i.e., they occur as extrazonal vegetation and cover significantly smaller areas than in the Illyrian province. In the area of Kosmaj, these forests occur at lower altitudes (300 - 400 m), with eastern to northeastern aspects, and the slope of 15-23°. Differentiation of flora was done according to membership in certain ecological plant groups, according to most significant ecological factors: soil humidity, soil acidity, quantity of nitrogen in the soil, light and temperature. According to the indicator values of plant species, the community of sessile oak and hornbeam is mesophilic in terms of humidity (F - 2.88), neutrophilic-basophilic (R - 3,32) in terms of acidity, mesotrophic in terms of soil nitrogen supply (N - 2,82), semisciophilic regarding light (L - 2,85), and mesothermal in terms of heat (T - 3,39). Indicator values of plants are suitable to indirectly assess environmental conditions and can help to estimate the conditions, for which no measurements are available. Therefore, they can be used as useful indicators in monitoring environmental changes. [ABSTRACT FROM AUTHOR]

Convolutional neural networks (CNNs) have demonstrated their efficacy in remote sensing applications for mountain forest classification. However, two-dimensional convolutional neural networks (2D CNNs) require a significant manual involvement in the visual interpretation to obtain continuous polygon label data. To reduce the errors associated with manual visual interpretation and enhance classification efficiency, it is imperative to explore alternative approaches. In this research, we introduce a novel one-dimensional convolutional neural network (1D CNN) methodology that directly leverages field investigation data as labels for classifying mountain forest types based on multiple remote sensing data sources. The hyperparameters were optimised using an orthogonal table, and the model's performance was evaluated on Mount Emei of Sichuan Province. Comparative assessments with traditional classification methods, namely, a random forest (RF) and a support vector machine (SVM), revealed superior results obtained by the proposed 1D CNN. Forest type classification using the 1D CNN achieved an impressive overall accuracy (OA) of 97.41% and a kappa coefficient (Kappa) of 0.9673, outperforming the U-Net (OA: 94.45%, Kappa: 0.9239), RF (OA: 88.99%, Kappa: 0.8488), and SVM (OA: 88.79%, Kappa: 0.8476). Moreover, the 1D CNN model was retrained using limited field investigation data from Mount Wawu in Sichuan Province and successfully classified forest types in that region, thereby demonstrating its spatial-scale transferability with an OA of 90.86% and a Kappa of 0.8879. These findings underscore the effectiveness of the proposed 1D CNN in utilising multiple remote sensing data sources for accurate mountain forest type classification. In summary, the introduced 1D CNN presents a novel, efficient, and reliable method for mountain forest type classification, offering substantial contributions to the field. [ABSTRACT FROM AUTHOR]

In Mediterranean areas, fire has increased soil degradation and erosion. For this reason, the application of soil quality indices can help to determine soil recovery and degradation levels. By using a multiparameter soil quality index fitted to undisturbed forest soils, we can show the right information on soil functionality. In this study, the objectives were to evaluate soil functionality after suffering a fire, to subsequently treat with various soil treatments (wood mulching), and then check a soil quality index (SQI) to assess the soil quality recovery in burned Pinus nigra stands. For this purpose, a burned area was selected in the Cuenca Mountain range (Spain) under a Mediterranean climate. Experimental plots were established in the study area, with three slope gradients and applying three methods of covering soil using: (1) wood chips; (2) piles of branches; and (3) trunks of contour-felled logs. The experiment was conducted for 4 years. Results showed that the properties of soil were enhanced under wood chips and logs as a surface-covering material, and in a short time (less of 3 years). In consequence, the values of the SQI index were higher after applying these two treatments, thus reflecting the effectiveness of the SQI for monitoring post-fire recovery. [ABSTRACT FROM AUTHOR]

Arctic outflow winds bring cold air from the continent to the coastline through mountain passes. Using observational data and a 2‐D model, we show that a February 2019 outflow event caused the upper 100 m in Bute Inlet, British Columbia (within the traditional territory of the Homalco Nation) to cool up to 1.9°C and gain up to 4.1 mLL−1 of oxygen. The cold, oxygenated water persisted for almost 1 year within the 1,023–1,023.5 kgm−3 isopycnal range (∼50–150 m). Atmospheric (from 1929 to 2022) and oceanographic (from 1951 to 2022) data showed a statistically significant relationship between continental air temperature at Tatlayoko Lake and temperature and oxygen in Bute Inlet. This local mechanism that counters some effects of climate change could create a biological refugium as surrounding waters warm and lose oxygen at a faster rate. The number of outflow events decreased from 1951 to 2018, and increased since. Plain Language Summary: There are times during most winters that Arctic air masses settle over the British Columbia (BC) interior east of the coast mountain range. Some of this cold air is transported to the coast as an outflow wind via coast mountain valleys. Using observational air and ocean data and a model, we examine an outflow event in February 2019. During this event, we find that outflow winds can cause mixing of the upper 100 m in Bute Inlet and this mixing can cause the ocean to rapidly cool and gain oxygen. Historical air data from 1929 to 2022 and ocean data from 1951 to 2022 were examined and it was found that the number of outflow events have generally decreased from the 1950s to 2018s, and increased afterward. This work identifies an important mechanism that could protect parts of BC's coastal ocean from climate change induced warming and loss of oxygen. Key Points: In February 2019, Arctic outflow winds caused the upper 100 m in Bute Inlet to cool by up to 1.9°C and gain up to 4.1 mLL−1 of oxygenApril to October Bute Inlet intermediate water properties are significantly correlated continental air temperature from the previous winterArctic outflow events decreased since the 1950s, but disruption of the polar vortex may increase these events with climate change [ABSTRACT FROM AUTHOR]

Snow cover plays a critical role in global energy and water cycles. Snow cover on the Tibetan Plateau (TP) provides vital water sources in western China and Himalayan regions, in addition to its weather and climate significance. The massive high mountain topography of the TP is the main condition for the presence and persistence of snow cover on the plateau at the mid-low latitudes of the Northern Hemisphere (NH). However, how the mountain topography controls snow-cover distribution on the TP remains largely unclear, and the relationship is not well quantified. Here, the spatial distribution and the topographic controls of snow cover on the TP are examined based on snow cover frequency (SCF) derived from MODIS snow cover product (MOD10A2 v005) and digital elevation model (DEM) data. The results show that snow cover on the TP is spatially unevenly distributed, and that it is characterized by rich snow and high SCF on the interior and the surrounding high mountain ranges, with less snow and low SCF in inland basins and river valleys. Snow cover on the TP presents elevation dependence: the higher the altitude, the higher the SCF, the longer the snow cover duration, and the more stable the intra-annual variation. The annual mean SCF below 3000 m above sea level (m a.s.l) is less than 4%, and it reaches 77% above 6000 m a.s.l. The intra-annual snow cover variation below 4000 m a.s.l features a unimodal distribution, while above 4000 m a.s.l it presents a bimodal distribution. The mean minimum SCF below 6000 m a.s.l occurs in summer, while above 6000 m a.s.l it occurs in winter. Due to differences in solar radiation and moisture condition caused by the mountain slope and aspect, the mean SCF generally increases with mountain slopes, and it is the highest on the north-facing aspect and the lowest on the south-facing aspect. [ABSTRACT FROM AUTHOR]

This study documented land degradation resulting from initial trail development and further high‐intensity touristic activity in a high‐altitude setting (>4000 m a.s.l.) in the Andes. Peru's Rainbow Mountain (also named Vinicunca or Montaña de Siete Colores) only became a world‐renowned tourist destination in recent years (after 2015/2016). A high‐mountain setting as such is fragile and does not recover fast, meaning the rapid influx of visitors has caused severe landscape degradation from which it will take several decades to recover. The main objectives of the study were to (1) characterise and map different types of impacts related to direct visitor pressure, (2) document and evaluate activities aimed at limiting degradation while enhancing visitors' experience, and (3) propose a conceptual model of trail functioning in the tropical high‐mountain environment. Data were collected using ground‐based surveys, unmanned aerial vehicles and high‐resolution satellite images. We identified eight dominant morphogenetic processes responsible for the transformation of landscape surface: (1) trampling, (2) abrasion/shearing by visitors and service animals and (3) transformation of water and sediment circulation—these direct human activities can initiate and/or intensify further degradation by the following natural processes: (4) water erosion, (5) freeze–thaw cycles, (6) dry‐wet cycles, (7) aeolian activities and (8) mass movements. The five main trail impacts identified were: trail widening, trail incision, formation of braided trail networks, development of muddy sections and development of informal (visitor‐created) trails. These observed impacts have left a clear imprint on the landscape after just one to two seasons of intensive recreational use. [ABSTRACT FROM AUTHOR]