旅游活动对黄石寨景区步道的影响评估

作为旅游景区基础设施的步道,高频率旅游利用会对其产生一定程度的影响。选取张家界森林公园的黄石寨景区为研究对象,运用"既成事实调查法",设置30个样点,选取了若干特征与指标来评估步道的受影响情况。结果显示,景区的步道扩展率为13.5%,步道冲蚀发生率为73.3%,步道损毁有14处,步道边缘的土壤性状和植被状况也发生了改变,这说明旅游活动对黄石寨景区步道产生了负面影响。而且山顶环寨游道受到旅游活动的影响最大,上山游道次之,下山游道最小,这与旅游利用强度密切相关。     

Geoecological approach to infrastructural development of hiking trails in federal-level SPNA (as exemplified by the Baikalskii nature reserve)

The comprehensive utilization of the technique for substantiating the promotion of hiking tourism, with emphasis on infrastructural development to ease access to recreational sites for different categories of visitors. The goal of using specialized hiking trails is to furnish a means of acquiring a familiarity with the unique landscapes of the Khamar-Daban mountain range. The technique contains four consecutive stages, and their implementation is illustrated in terms of the model territory. An analysis is made of the socioeconomic and geoecological characteristics of the Baikalskii Biosphere Reserve, which, together with landscape assessment, serves as a basis for the generation of the zoning map for possibilities and restrictions as regards the promotion and development of hiking tourism. A zoning is provided, which takes into consideration the possibilities of hiking tourism, based on assessing a territory’s transport accessibility, estimating the cost of preparing a trail of each class, and on the geoecological characteristics of landscape. The map that identifies seven zones of different-intensity transformation of the territory for an integral development of hiking tourism is used in making recommendations for the preparation of hiking trails in the Baikalskii Nature Reserve. The landscapes are combined into zones according to the degree of suitability for the construction of trails of different classes. The algorithm for preparation of trails consisting of 10 consecutive stages (three stages of planning, and seven stages of preparation) is applied for a number of linear features. The most suitable classes of preparation are indicated for these trails, in accordance with the characteristics of landscapes and engineering restrictions within their boundaries.     

Estimated travel time for walking trails in natural areas

An increase in walking or hiking activities in natural areas requires improvements in information and advice about trails, including their difficulty, available services and estimated travel time. Comparative studies show remarkable differences between measured and calculated travel times obtained by available predictive procedures (Naismith’s rule, Tobler’s hiking function or MIDE). A new procedure has been designed by combining pre-existing methods (Tobler’s and MIDE), and travel times have been calculated for 21 trails located in different protected natural areas of Spain. Times obtained are compared with travel times measured by individual users and uploaded into specialized walking-hiking websites (Wikiloc). Results show that the new procedure (Modified Tobler) reduces differences between calculated and measured travel times, which makes it suitable not only for trail managers to estimate travel times but also as a key part of pedestrian transport analysis in trail networks.     

Drought is the major limiting factor for tree-ring growth of high-altitude Canary Island pines on Tenerife

This is a detailed study of 50 wood cores sampled from 25 Canary Island pines ( Pinus canariensis ) growing in a subtropical climate close to the tree limit (at Lomo de Retamar, 2000–2100 m a.s.l.) on the southern, leeward side of Tenerife.
The Canary Island pines form tree-rings and, similarly to temperate pines, earlywood is formed during spring. But many pines fail to form tree-rings every year and one purpose for this paper has been to find a way to overcome this problem. Another purpose has been to see what correlations, if any, exist between the ring widths and meteorological data. Meteorological data have been collected since 1916 at the nearby Izaña meteorological observatory. It was also important to find the limiting factor for growth of Canary Island pines close to the tree limit.
Through cross-dating, missing rings were found to be typical for younger parts of older trees; in the same years younger trees instead had low growth. Some trees lacked more than 20 rings in a century. This study shows that it is possible to compensate for missing rings, at least when the number of missing rings is less than 10%.
Correlation studies showed that the growth of the tree rings was mainly due to the precipitation factor, particularly the annual precipitation one year before the ring formation, but also due to temperature. Strangely enough, multiple linear regression gave the highest correlation coefficient (0.50) for a combination of annual precipitation one year earlier and temperature four years earlier.     

Planning of recreational trails in protected areas: Application of regression tree analysis and geographic information systems

One of the most important tasks for managers of many natural protected areas is achieving a balance between conservation of nature and recreational opportunity. This paper presents a framework based on geographic information system (GIS) and regression tree analysis of optimized recreational trail location for flexible, user-defined input parameters. The method utilizes: (1) the GIS to create a database containing field data and existing GIS/cartographic materials; (2) regression tree analysis to establish the relationships between indicators of degradation and environmental and use-related factors for existing trails, as well as to predict trail degradation for potential new trials; (3) least-cost path algorithm within a GIS framework to optimize trail route.The framework was applied to the Gorce National Park in the south of Poland. A large sample (>4500) of the field collected data about degradation of the existing trail network was linked with data about soil, geology, geomorphology and relief, and with information about the type and amount of recreational use. Based on the existing relationship, predicted trail degradation was calculated and routes for two examples of trails (hiking and motorized) were designated. The proposed methodology is objective and quantitative, and can also include knowledge of local stakeholders. The framework has the potential to design new trails (or to re-route old ones), characterized by the best possible solution for recreational and conservation functions to coexist, by routing visitors through trails with the lowest possible impact.     

Tree roots — Methodological review and new development in dating and quantifying erosive processes

Exposed roots have been used in Dendrogeomorphology since the 1960s to determine erosion rates. This was done by using the root axis as the relative position of the former soil layer and then relating this measure to the age of the root in order to quantify the amount of soil erosion over time. Recently, wood anatomical research revealed the possibility of determining the first year of exposure of roots due to specific anatomical changes within the respective annual ring. As a consequence, using exposed roots that are still in contact to the soil surface, it is possible to reconstruct the size and position of the root at the time of exposure. Consequently, a new equation is presented to calculate the thickness of the eroded soil layer allowing a detailed reconstruction of erosion rates. The technique also helps to determine if the root was exposed by erosional processes or just by its ongoing secondary growth without any erosion involved.     

基于根系解剖结构的金沙江干热河谷土壤侵蚀速率估算

基于侵蚀过程会导致树木生长环境变化,进而改变根系生长生理特征的基本研究思想,以金沙江干热河谷龙川江流域为典型区,从树根细胞解剖结构和组合特征的变异中提取土壤侵蚀信息,探索和发展了基于树木生理生态的土壤侵蚀研究新方法与技术。结果表明,不同侵蚀强度下根系的年轮分布特征不一致,其中偏心率大小顺序为:局部暴露根系>浅埋根系>完全暴露根系,且偏心率与根系以上土层厚度、暴露程度存在显著性相关;根系导管面积是反演侵蚀过程的敏感指标,早材导管面积的变异是确定根系暴露时间的重要依据之一;龙川江流域土壤流失厚度为1.47~4.47 mm/a,平均侵蚀模数约为3 692 t(/km2.a)。     

Dating of small gully formation and establishing erosion rates in old gullies under forest by means of anatomical changes in exposed tree roots (Southern Poland)

Small gullies occur in forested gully systems on the undulating loess plateau in southern Poland. The old gully hillslopes are mainly covered with 200-year old beech trees in contrast with the surface of the summit plateau, which is cultivated agricultural land. Beech roots are exposed in the gullies through erosion. Wood vessels in the root tree rings divide into early wood and late wood and, after the roots are exposed, start to make fewer vessels. These anatomical changes in root tree rings allow us to date erosion episodes.Small gullies form in a different manner on the valley floor and on hillslopes. In valley bottoms, erosion features are often formed at some distance from one another, and in time small gullies combine to form a single, longer one. Depending on local conditions, such as the hillslope profile, hillslopes may exhibit headward erosion or may be eroded downwards. Hilllope gullies may be transformed into side valleys as a result of gradual widening and deepening.Dating the exposure of roots indicates that small gullies had already formed in the valley system by 1949. Intensive gully erosion was recorded between 1984 and 2002, during intense precipitation in 1984 and, of particular note, during the extraordinary flood of 1997 which affected all of Central Europe. The mean rate of small gully erosion in the old gully system studied is 0.63 m/year. On hillslopes the mean gully erosion rate is 0.21–0.52 m/year, and on the valley bottoms 0.18–1.98 m/year. High bottom erosion rates resulted from the emergence of long gullies during the erosion episodes in 1984 and 1997. Sheet flow in valley floors intensifies at times of heavy rainfall which causes long gullies to form.Taking into account the fact that conditions favoured erosion, the rate at which the old gullies under forest were transformed should be considered slow. New side gullies form slowly within the valley and it appears that if erosion progressed at the rate observed, new side valleys would take a few hundred years to form.     

A 200-Year Tree-Ring Chronology of Pine from a Raised Bog in Sweden: Implication for Climate Change?

A dendrochronological study was made on fossil tree trunks of Scots pine, Pinus sylvestris , preserved in a peat bog at Hanvedsmossen, 50 km SW of Stockholm, Sweden. Of 56 sampled pines, 48 were assembled in a 204-year long floating chro-nology. The chronology spans 1686-1483 BC ± 23 years. The trunks are found at the very bottom of the peat accumulation. Because the roots stand in underlying clay, the tree stand germinated before or simultaneously with bog growth and provides maximum age for bog vegetation development which started c . 1480 BC. The pine growth steadily decreased during the last 30 years of the chronology and most trees died during the same period. It is proposed that the drainage outlets from Hanvedsmossen overgrew with brushwood simultaneously with the succession of pines, resulting in a higher sensitivity of tree growth to small changes in water levels. The preservation of the logs is suggested to be a result of a raised water table providing anaerobic conditions and later the logs were enveloped by peat growth. It is suggested that this period was the initial phase of the ensuing climate deterioration. The climate shifted to wetter conditions, i.e. higher amounts of precipitation, lower temperature or both. This resulted in lower evaporation giving additional peat bog growth and a locally raised water table.     

Soil erosion rates in rangelands of northeastern Patagonia: A dendrogeomorphological analysis using exposed shrub roots

Soil erosion is an important process of land degradation in many rangelands and a significant driver of desertification in the world's drylands. Dendrogeomorphology is an alternative to traditional methods for determining soil erosion rate. Specifically, the vertical distance between the upper portion of exposed roots and the actual soil surface can be used as a bioindicator of erosion since plant establishment. In this study, we determined (i) the soil erosion rate from exposed roots of the dwarf shrub Margyricarpus pinnatus [Lam.] Kuntze in two ecological sites in the northeastern rangelands of Patagonia and (ii) the relationship between shrub age and upper root diameter. We selected two ecological sites, a pediment-like plateau and a flank pediment, where the dominant soils were Xeric Haplocalcids and Xeric Calciargids, respectively. The soil erosion rates in the pediment-like plateau and in the flank pediment were 2.4 and 3.1 mm yr^− 1, respectively. Data clearly indicate a high rate of soil erosion during the mean 8-year life span of the dwarf shrubs in degraded patches, which represent ~ 10% of surface cover in the study area. Simple linear regression analysis yielded a highly significant predictive model for age estimation of M. pinnatus plants using the upper root diameter as a predictor variable. The measurement of ground lowering against datable exposed roots represents a simple method for the determination of soil erosion rates. In combination with other soil surface features, it was used to infer the episodic nature of soil erosion. This approach could be particularly useful for monitoring the effects of land management practices on recent soil erosion and for the establishment of records in regions where historical data regarding this process are scarce or absent.     

Ecological criteria, participant preferences and location models: A GIS approach toward ATV trail planning

This paper presents a geographic information system (GIS)-based method for recreational trail location for all-terrain vehicles (ATVs) which considers environmental factors, as well as rider preferences for trail attributes. The method utilizes the Least-Cost Path algorithm within a GIS framework to optimize trail location. The trail location algorithm considered trail impacts and benefits associated with water bodies, slope, land ownership, noise, trail separation, views, and rider preferences for vegetation types and loop trails. Alternative trails were generated to highlight the influence of different preferences for trail attributes and to demonstrate the capabilities of the Least-Cost Path algorithm as applied to trail location. The method shows promise for use in generating ATV trails, as well as other types of recreational trails, for consideration in recreational planning and analysis.     

浑善达克沙地黄柳人工林根系分布及生物量研究

 对浑善达克沙地一年生、二年生、三年生黄柳人工林根系分布及生物量进行了调查、测定。结果表明:①在流动沙丘上人工栽植的黄柳,其根系主要由直径小于2.0 mm的中根和细根构成,其数目占剖面根系总数的90%以上,其中又以直径小于0.5 mm细根所占比例最高,其数目占剖面根系总数的50%以上。②根系主要分布在10～30 cm的土层中,可见其根系主要吸收10～30 cm土层内的水分和养分。③根系重量在各土层中呈随土层深度加深而降低的分布趋势。④根系主要呈水平分布,水平根非常发达,随着植株的不断生长,这一特征越来越明显。     

高寒沙地乌柳(Salix cheilophila)林根系分布特征

对青海共和高寒沙地植被恢复区不同林龄(6年、11年、16年和21年)乌柳(Salix cheilophila)人工防护林根系分布及根量进行了调查、测定,同时测定了土壤有机质含量的垂向变化。结果表明:①不同林龄乌柳林根系主要由中根和细根构成,其数目占土壤剖面根系总数的90%以上,其中又以直径小于2.0mm细根所占比例最高,细根占剖面根系总数的50%以上;②各林龄乌柳根系在0~50cm土层分布较为集中,在30cm以下土层,根量随深度的增加逐渐减少,6年生乌柳林根系垂直分布在0~130cm,20年生乌柳可达200cm,随植被恢复时间的增长,各林龄根量显著增加(p0.05);③各林龄乌柳林有明显发达的垂直主根,属典型的垂直状根系,随植株不断生长,根系表现出深根性;④以不同深度根系重量作为解释变量,以土壤有机质含量作为响应变量,回归结果显示不同林龄乌柳林根系重量显著影响土壤有机质含量(p0.001),这也为评价沙地植被改良土壤功能提供了依据。     

Access,Equity, and Urban Greenways: An Exploratory Investigation

Recurring issues in the social sciences concern the distribution of public facilities such as parks and equity of access to them. Geographers have observed that access has perceptual as well as physical dimensions and that perceptions of difference can affect use of public space. This study explores the nature of greenways as public space and a set of issues related to equity of access to greenway trails in Indianapolis, Indiana. The study uses proximity as a measure of access and simple GIS analyses of census and other data to assess equality of access. Evidence is provided that suggests that minorities and the poor have disproportionate access to trails. It is also shown that populations adjacent to the trails differ and that the populations along particular trails are segregated. Spatial differences in trail populations are associated with historic land use patterns and population movements within the city. The implications of the findings of difference for use of the greenways system are explored. Implications for management of the greenways system—including achievement of the goal of linking neighborhoods—are also discussed.     

Footpath erosion in the English Lake District

Footpath erosion is a matter of concern in the English Lake District, where recreational pressure on the fells is increasing. Erosion may be expected to result from the interaction of recreational geomorphological and climatic forces with the inherent resistance of vegetation and soil conditions. A broad-scale survey of 485 sites on 25 paths in the Lake District demonstrated the importance of specific variables for footpath erosion. Erosion (measured as path width, extent of bare ground or maximum depth) is found to increase with the square root of the slope angle and the square of the recreation pressure. These two variables also interact with each other, while other factors, such as vegetation type, soil type and topographic position, also influence rate of erosion. A threshold slope angle of 15–17° seems to separate actively eroding from stable slopes.     

Frequency of debris flows and their relation with precipitation: A case study in the Central Alps, Italy

Debris flows are very important and widespread mass movements, and represent a remarkable geomorphological hazard. This research deals with debris flows in an alpine environment, studied using dendrogeomorphological dating techniques, outlining their relation with precipitation, and analysing possible changes in their frequency and intensity over time. The study area is the upper Valle del Gallo (Northern Italy), a typical high mountain environment dominated by mass wasting processes, where many debris-flow fans occupy the valley bottom. Dendrogeomorphological research was conducted on twelve of these fans and two channels located on slopes. Tree growth anomalies (abrasion scars, compression wood and abrupt growth changes) were used as dating methods. Two hundred and thirty nine debris debris-flow events between 1875 and 2003 were dated using 757 trees (Pinus montana Mill.). Analysis between dated events and precipitation suggests that debris flows in the study area could be triggered by 20–30 mm of rain concentrated in a few hours. The debris-flow frequency tends to increase gradually, but the highest value seems to have occurred in the period 1974–1983. This trend agrees with the historical occurrence of flooding events in Northern Italy as inferred by literature, and with similar studies conducted in the Swiss Alps. The results of this research are intended as a contribution for understanding the response of geomorphological processes to climatic changes.     

杉木人工林细根寿命研究

林木细根（≤2mm）是树木水分和养分吸收的主要器官,是陆地生态系统净生产力的重要组成部分,深入理解细根生长过程及其寿命是建立全球碳及养分循环模型的关键．本试验采用微根管技术对11年生杉木（Cunninghamia lanceolata）人工林细根生长、衰老、死亡的动态过程进行了为期1年半的监测,运用Kaplan—Meier方法估计细根存活率及中值寿命（Median root longevity,MRL）,生成存活曲线（Survival curve）．用对数秩检验（Log—rank test）比较不同直径、不同土层、不同季节出生的细根寿命差异程度．结果表明,细根主要出．现在雨季（3q月）,以直径0～1mm的细根为主,并随观测期的延长,细根存活率下降,中值寿命为236d．直径0～1mm的细根累积存活率小于1～2mm的细根．土壤下层（20～40cm）的生存曲线在细根累积存活率达到50％以后始终高于上层（0～20cm）,上下层中值寿命分别为236d和243d,这可能与土壤环境因素的垂直分布相关,下层土壤有利于延长细根寿命．不同出生时间的细根寿命不同,雨季与干季出生的细根中值寿命分别为86d和270d．     

Biogeomorphological influence of slope processes and sedimentology on vascular talus vegetation in the southern Cascades, California

The vascular vegetation of alpine talus slopes between 2035 and 3095 m altitude was studied at Lassen Volcanic National Park (California) in the Cascade Range. Taluses show a diverse flora, with 79 plant species; growth forms include coniferous trees, shrubs, suffrutices, herbs, graminoids, and ferns. Spatial patterns of plant distribution were studied along 40 point-intercept transects. Plant cover was low (0-32.7%) on all slopes, spatially variable, and showed no consistent trends. Sedimentological characteristics were determined by photosieving next to 1500 plants; this census indicated preferential plant growth on blocks and cobbles, with 43.2% and 23.3% of the plants growing on these stones, respectively; fewer specimens were rooted on pebbles (13%) or on stone-free gravel areas (20.5%). Growth forms displayed different substrate preferences: 92.5% of the shrubs and 83% of the suffrutices colonized blocks or cobbles, but only 57.2% of the herbs and 59.8% of the graminoids grew on large stones. Plants are associated with large clasts because (1) coarse talus is more stable than fine sediment areas, which are more frequently disturbed by various geomorphic processes, and (2) large stones help conserve substrate water beneath them while moisture quickly evaporates from fine debris.Root patterns were studied for 30 plant species; 10 specimens for each species were excavated and inspected, and several root growth ratios calculated. All species exhibited pronounced root asymmetry, as roots for most plants grew upslope from their shoot base. For 23 species, all specimens had 100% of their roots growing upslope; for the other 7 species, 92.2-99.3% of below-ground biomass extended uphill. This uneven root distribution is ascribed to continual substrate instability and resulting talus shift; as cascading debris progressively buries roots and stems, plants are gradually pushed and/or stretched downhill. Various disturbance events affect root development. Slope erosion following rubble removal often exposes plant roots. Debris deposition can completely bury plants; some may survive sedimentation, producing new shoots that grow through accumulated debris. Shrubs may propagate by layering, as adventitious roots develop along buried stems; or produce new clones along their roots. Slope processes may damage and transport plant pieces downhill; some species can sprout from severed, displaced root or stem fragments. Vegetation interacts with several geomorphic processes, including debris flows, grain flows, rockfall, snow avalanches, frost creep, and runoff. Larger plants may alter local patterns of debris movement and deposition, damming cascading debris on their upslope side and deflecting sediments laterally to plant margins, where they form narrow elongated stone stripes.     

Historical and Projected Climate Trends Along the Appalachian Trail,USA, and the Implications for Trail Usage

Recent climate analyses indicate that average global temperature is rising and both global drought occurrence and precipitation intensity are increasing. The nature of climate change is unique to each location, and its impact, both positive and negative, is predicted to be widespread. One area to be potentially affected includes management and use of outdoor natural resources such as the Appalachian Trail (AT), a 3500 km continuous hiking trail in the eastern United States. Observed historical (1895-2008) and projected future (to 2099) seasonal temperature and precipitation trends were examined along the AT. The AT has generally warmed since 1895, with greater warming occurring more recently. The warming has been greatest in the northern part of the AT and during winter. Precipitation trends show wide spatial variation depending upon the season, but generally precipitation has increased more in the northern than southern AT. Temperature and precipitation are projected to increase for all regions during all seasons in the future. Implications of these changes are discussed with respect to hiker experience and trail management.     

基于SPSS大连徒步旅游游客满意度研究

徒步旅游已成为旅游市场主流,作为一种时尚的自助旅游形式,深受独立旅行能力的旅游者所喜爱。徒步旅游市场前景广阔,研究徒步旅游满意度对发展徒步旅游意义重大。以大连徒步旅游为研究对象,采用问卷调查方法和spss统计分析方法,通过相关分析以及配对样本r检验,了解到徒步者对徒步体验的重视度与满意度之间存在显著性差异,普遍存在高重视程度、低满意度的情形。徒步者最为满意的是“滨海、山体风景”,而“洗手间问题”、“休息饮水处”、“交通距离”、“医疗应急安全措施”以及“购物便利度及价格”这5项满意度最低。