Effects of ski resort management on vegetation

We investigated species composition and characteristics of plant communities in plots at seven site types within a ski resort: forests, an abandoned ski slope, an area under the gondola lines, forest waterfronts, open waterfronts, edges of ski slopes, and an active ski slope. On the abandoned ski slope, under the gondola lines, at the edges of ski slopes, and on the ski slope, canopy closure was low, tall herbs were present, and species diversity was high. Some wetland species were present at waterfront plots. Differential species composition was caused by vegetation cutting, which was necessary to manage the ski resort. We found various plants, including herbs, some rarely seen because their habitats have decreased. Despite their negative effects, such as surface-soil erosion and magnification of plant size due to the use of ammonium sulfate, ski resorts can be important plant habitats with highly diverse species composition.     

Effect of snowpack management on grassland biodiversity and soil properties at a ski resort in the Mediterranean basin (central Italy)

In the Mediterranean basin, the activity of ski resorts below 2000 m of altitude strongly affects grassland ecosystems because of the increasing use of artificial snow (AS). In a representative ski resort of central Apennines (Italy), we studied soil, vegetation and topographic variables of three adjacent grasslands: undisturbed grassland (UG), ski-runs with natural snow and ski-runs with amassed and AS. The winter temperature at the soil surface was colder in the ski-runs (even more in AS) than in the UG with an increase in dissolved organic matter and a biomass decrease. We identified 21 diagnostic species and 14 functional bioindicators linked to soil indicators like surface temperature and moisture. Conversely to observations made in the Alps and in other sites of the Apennines, we did not record any significant decrease in the floristic diversity between ski-runs and UG. Ski-run management aimed to prolong the snowpack duration-induced higher soil humidity and a short vegetative growth that produced a significant shift of the natural structure and composition of the grassland. To preserve key habitats for biodiversity, the construction and extension of ski resorts below the altitude of 2000 m should be avoided in the climatic belt of the Apennines.     

Ski slope vegetation at Snoqualmie Pass, Washington State, USA, and a comparison with ski slope vegetation in temperate coniferous forest zones

Ski slope vegetation at Snoqualmie Pass in Washington State, USA, was surveyed in order to identify community types and to compare it with vegetation development patterns in Japan. Ski slopes in Japan, most of which were constructed after 1960, underwent heavy land recontouring, while those at Snoqualmie Pass were constructed before 1950 with less modification. Three points apply to Japanese ski slope vegetation and differentiate these slopes from those at Snoqualmie Pass: (i) grasslands of introduced species are widespread and persistent; (ii) unvegetated patches are uncommon; and (iii) wetland vegetation has developed. These differences are mainly derived from the intensity of human impact, history of the slope and its scale: namely, ski slopes in Washington are older and larger than those in Japan. Ski slope vegetation in Washington was primarily differentiated by a soil moisture gradient. The large size of Washington ski slopes permitted the inclusion and development of wetland habitats, whereas most ski slopes in Japan are constructed on ridges and do not contain wetlands. Most introduced species in Japan are eliminated soon after seeding. In contrast, the long-term management of ski slopes decreased soil erosion and/or unvegetated patches in Washington and created relatively permanent grasslands composed of introduced species. Tsuga heterophylla and Abies amabilis were found established on the ski slopes in Washington, whereas in Japan the pioneer tree species are shade-intolerant broadleaved species. These differences may be a result of the different disturbance histories of ski slopes in the two countries. In addition, along with the conifers, early successional forbs such as Anaphalis margaritacea and Epilobium angustifolium are well established on Washington ski slopes. Results show that disturbances created by ski slope development greatly affect the vegetation, even on older, less heavily impacted ski slopes.     

Miscanthus sinensis grassland is an indicator plant community to predict forest regeneration and development on ski slopes in Japan

Most ski slopes in Japan are established by forest clearcutting, scraping off the ground surface and thereby artificial seeding in well-developed forests. Recently, some ski slopes have been abandoned owing to economical failure, and more skis resorts will go bankrupt. To restore abandoned ski slopes, therefore, we have to find out appropriate indicators to restore forest cover with low cost. Vegetation data were collected in Yuzawa, central Honshu, Japan (500–760 m elevation), where ski slopes are over-concentrated. To predict the possibility of forest development, relationships between tree stem density and vegetation characteristics were examined. Trees did not establish in areas where the introduced plant cover was more than 40%. Of native grasslands, Miscanthus sinensis grassland showed the highest stem density but did not show high species richness. In particular, stem density increased with increasing M. sinensis cover. To indicate advanced successional sere towards forests, therefore, M. sinensis cover is a more appropriate indicator rather than species richness.     

Direct and indirect effects of ski run management on alpine Orthoptera

Alpine landscapes are heavily influenced by ski run management, which can have severe impacts on alpine biodiversity. To assess these impacts on alpine Orthoptera, we compared species richness and species abundance in 41 plot pairs on ski runs and adjacent off-slope control plots in three ski resorts in Austria and Germany. A mixed modelling approach was used to assess the impacts of ski run preparation, artificial snow-making and environmental variables such as altitude, cover of dwarf shrubs and the application of fertilizer. Ski run plots showed a significantly lower species richness and number of individuals than control plots. Moreover, artificial snow led to a further decrease in species number. Hierarchical variance partitioning revealed that Orthoptera community composition is best predicted by environmental variables indirectly related to ski run management (fertilization, cover of dwarf shrubs) and to altitude. Only one out of five species significantly decreased in abundance after artificial snow-making. Other species were more sensitive to fertilizing and altitude. Dwarf shrubs were negatively associated with ski run management but positively associated with abundance of three species and species richness. Our data provide evidence for both direct and indirect consequences of ski runs and artificial snow-making on alpine Orthoptera. Overall, Orthoptera communities are suitable indicators for human-induced changes in alpine environments. In particular, a shift towards generalist species such as Chorthippus parallelus along with a decrease in typical alpine species gives cause for concern as this implies a homogenisation of biodiversity owing to ski run management.     

Influence of soil heterogeneity on water regime and yields of lucerne,sugar beet and wheat

Lucerne plants in the first crop year as well as plants of spring wheat from different sites of the respective experimental plots showed differences in sap exudation from detopped roots or from stumps of the main shoots, reflecting differences in properties of the soil profile. The differences in sap exudation were observed at a time when the plants did not show any visible differences in water availability. Differences in the water potential deficit of the leaf blades of lucerne plants in the second crop year and of sugar beet plants, related to differences in soil profile properties, were observed in another series of experiments. Sugar beet plants showed a higher physiological lability than lucerne plants. The sites characterized by unfavourable plant-water-relations usually gave lower yields. The coefficients of variability for the yields of lucerne fresh matter from irrigated plots were three times lower than those for yields from plots without irrigation, influenced by soil heterogeneity.     

Nitrogen fertilizer enhances vegetation establishment of a high-altitude machine-graded ski slope

Machine grading is frequently required to prepare the terrain when building high-altitude ski slopes in the Alps. However, this kind of disturbance alters the natural environment, destroying the vegetation and hampering its reestablishment. Thus, specific restoration plans are necessary to encourage the recovery of vegetation, which is already affected by different natural constraints in this harsh environment. One of the main critical factors affecting plant growth in high-altitude areas is the lack of available nitrogen (N) in the soil. In this context, the addition of a slow-release N fertilizer was carried out in an experimental revegetated ski slope between 2,800 and 2,900 m above sea level in the western Italian Alps. Both vegetation and soil were monitored during a 5-year period in order to test the effectiveness of N addition on the restoration process. Even if effects on soil carbon and N contents were negligible, vegetation was remarkably affected by the fertilization, since the total vegetation cover and the species richness significantly increased. Against the expectations, there was a remarkable increase in spontaneous forbs, rather than in most of the sown graminoids, which slightly varied during the experimental period. Actually, graminoids responded in different ways, mostly increasing (likewise forbs), but the slight decrease of the dominant Festuca nigrescens (Chewing's Fescue) masked their spread. This study confirms the noteworthy role of N in high-altitude alpine soils and consequently its importance to improve the restoration process of degraded ecosystems.     

Responses of assemblages of Orthoptera to management and use of ski slopes on upper sub-alpine meadows in the Austrian Alps

The Orthoptera assemblages occurring on sub-alpine ski slopes were compared with those found on neighbouring unskied meadows by making frequent transect counts at two pairs of sites in the Gastein valley in the Austrian Central Alps. On one of the ski slopes no Orthoptera were present, although two species were abundant on the control meadow a few meters away. On the second ski slope, the Orthoptera assemblage exhibited reduced species richness, lower densities of individuals and a generally accelerated rate of nymphal development compared to the control meadow populations. These results may be explained in terms of the changed habitat conditions on the ski slopes and the known biologies of the species concerned. The implications of the findings for winter tourism management in high altitude ecosystems are briefly discussed.     

Uptake of water by lateral roots of small trees in an Amazonian Tropical Forest

A pulse chase technique was used to determine depth and breath of plant water uptake in an Amazonian evergreen forest. Two 2×2 m² plots were irrigated with deuterated water. The deuterium pulse, measured as D values of soil and plant sap water, was followed in the soil water profile and in stem water of small trees inside and up to 12 m away from the irrigated plots. The deuterium pulse percolation rate was measured to be approximately 0.25 m/month and similar to a previous study in central Amazon. There was little horizontal movement of label through the soil profile; allowing us to conclude that any evidence of label in plants away from the irrigation plots implies the presence of their roots inside the irrigation plots. The bulk of label uptake occurred in plants inside the irrigation plots. However, there were a few individuals as far as 10 m away picking up the label from the irrigation plots. This labeling pattern leads to the conclusion that small trees may have a core of water absorbing roots close to their main trunk, with some roots meandering far from their main trunk.     

Restoration ecology research above the timberline: colonization of safety islands on a machine-graded alpine ski run

Colonization was studied in safety islands installed on a machine-graded downhill ski run (ca 2500m asl) and respectively aged 7, 8, and 9 years. For comparison, the neighbouring non-restored plots were investigated. The study included assessment of species richness (alpha diversity), size and spatial structure of the immigrant populations, and the nearest possible diaspore sources. The number of colonizing species recorded in the safety islands totalled 44 whereas only 25 species were found in the non-restored ski run plots close by. The mean species number per whole plot, per 1m2 and per 0.1m2 was significantly higher in the safety islands than in the non-restored ski run plots. Population founders and small populations represented more than half of all immigrant species in the safety islands, but medium-sized and large populations were also present. The overall distribution of plants was patchy but the number of individuals per 1m2 was significantly higher in the safety islands than in the ski run. Travelling distances separating the safety islands from the nearest possible diaspore source were often exceedingly short and ranged between 0.10m and 1m in 47.7% of all populations studied. It seems that the diaspore sources were mostly secondary i.e. plants scattered over the non-restored ski run, and those previously used in restoration trials, served as diaspore donors. The results of the study clearly demonstrate that successful colonization of machine-graded alpine ski runs in the study area is ultimately limited by safe-site availability and not by deficiencies in seed rain or remote diaspore sources. The colonization process in the safety islands is apparently well-advanced. This revised version was published online in August 2006 with corrections to the Cover Date.     

EMG activities and plantar pressures during ski jumping take-off on three different sized hills.

Different profiles of ski jumping hills have been assumed to make the initiation of take-off difficult especially when moving from one hill to another. Neuromuscular adaptation of ski jumpers to the different jumping hills was examined by measuring muscle activation and plantar pressure of the primary take-off muscles on three different sized hills. Two young ski jumpers volunteered as subjects and they performed several trials from each hill (K-35 m, K-65 m and K-90 m) with the same electromyographic (EMG) electrode and insole pressure transducer set-up. The results showed that the differences in plantar pressure and EMGs between the jumping hills were smaller than expected for both jumpers. The small changes in EMG amplitudes between the hills support the assumption that the take-off was performed with the same intensity on different jumping hills and the timing of the gluteus EMG demonstrates well the similarity of the muscle activation on different hills. On the basis of the results obtained it seems that ski jumping training on small hills does not disturb the movement patterns for bigger hills and can also be helpful for special take-off training with low speed.     

The influence of ants on soil and water losses from an orange orchard in eastern Spain

Herbicide applications have greatly reduced plant cover, and increased soil erosion on a new orange orchard planted on valley slopes in eastern Spain. This has increased the importance of soil fauna, such as ants, in regulating soil erosion processes. Ants increase water infiltration rates by forming soil macropores during nest construction, but new soil brought to the surface by ant activity could increase the sediments available for erosion. Simulated rainfall experiments were conducted on 20 paired plots (20 with ant activity and 20 controls) to study the impact of ants on surface water flow and sediment movement in an intensively managed orange orchard near Valencia, Spain. Simulated rainfall was applied to each plot at a rate of 55 mm/h on a 0.25 m² area for 1 h. We found a reduction of soil bulk density, an increase in soil organic matter, and an increase in macropore flow in ant‐affected soils, as compared to soil without ant activity. These ant‐induced soil changes increased water infiltration rates and runoff discharge. However, the fresh, unconsolidated soil brought to the surface during nest construction resulted in greater soil loss on two plots than their ant‐free controls. Ants can be an important factor in soil erosion processes when surface vegetation is removed by intensive herbicide use.     

Take-off aerodynamics in ski jumping

The effect of aerodynamic forces on the force-time characteristics of the simulated ski jumping take-off was examined in a wind tunnel. Vertical and horizontal ground reaction forces were recorded with a force plate installed under the wind tunnel floor. The jumpers performed take-offs in non-wind conditions and in various wind conditions (21-33 m s(-1)). EMGs of the important take-off muscles were recorded from one jumper. The dramatic decrease in take-off time found in all jumpers can be considered as the result of the influence of aerodynamic lift. The loss in impulse due to the shorter force production time with the same take-off force is compensated with the increase in lift force, resulting in a higher vertical velocity (V(v)) than is expected from the conventional calculation of V(v) from the force impulse. The wind conditions emphasized the explosiveness of the ski jumping take-off. The aerodynamic lift and drag forces which characterize the aerodynamic quality of the initial take-off position (static in-run position) varied widely even between the examined elite ski jumpers. According to the computer simulation these differences can decisively affect jumping distance. The proper utilization of the prevailing aerodynamic forces before and during take-off is a very important prerequisite for achieving a good flight position.     

Soil and plant water relations in a crested wheatgrass pasture: response to spring grazing by cattle

Summary Few field studies have attempted to relate effects of actual livestock grazing on soil and plant water status. The present study was initiated to determine the effects of periodic defoliations by cattle during spring on soil moisture and plant water status in a crested wheatgrass (Agropyron cristatum (L.) Gaertn. and A. desertorum (Fisch. ex Link) Schult.) pasture in central Utah. Soil moisture in the top 130 cm of the soil profile was depleted more rapidly in ungrazed plots than in grazed plots during spring and early summer. Soil moisture depletion was more rapid in grazed plots in one paddock after 1 July due to differential regrowth, but there was no difference in soil water depletion between plots in another paddock during the same period. This difference in soil water depletion between paddocks was related to a difference in date of grazing. Although more water had been extracted from the 60 cm to 130 cm depths in ungrazed plots by late September, cumulative soil moisture depletion over the entire 193 cm profile was similar in grazed and ungrazed plots. Prior to 1 July, grazing had no effect on predawn leaf water potentials as estimated by a pressure chamber technique; however, after 1 July, predawn leaf water potentials were lower for ungrazed plants. Midday leaf water potentials were lower for grazed plants before 1 July, but did not differ between grazed and ungrazed plants after 1 July. A 4- to 8-day difference in date of defoliation did not affect either predawn or midday leaf water potentials. The observed differences in water use patterns during spring and early-summer may be important in influencing growth and competitive interactions in crested wheatgrass communities that are subject to grazing by domestic livestock.     

Seasonal changes in water source of four families of loblolly pine (<Emphasis Type="Italic">Pinus</Emphasis><Emphasis Type="Italic">taeda</Emphasis> L.)

Source water utilized by four families of loblolly pine (Pinus taeda L.) was assessed by comparing the H isotope composition ('D) of xylem sap and of soil water from four depths (0-20 cm, 20-40 cm, 1.2 m, and 2.1 m) across 1 year. Soil water 'D values varied with soil moisture content in the well-drained, sandy site and at each of the four soil depths. In September and November 1997 and May through November 1998, xylem sap 'D values closely matched the soil water 'D values of the upper soil horizons (0-20 and 0-40 cm) and, therefore, reflected significant water uptake from upper regions of the soil profile. In March 1998, xylem sap 'D values closely matched the soil water 'D values of the 1.2 m soil depth and, therefore, indicated that trees during this portion of the growing season were obtaining their water from deep in the soil profile. Analysis of source water use with a two-ended mixing model in the 3 months of collection that exhibited a range of soil water 'D values across the soil profile confirmed that trees utilized different sources of water depending upon season of the year. In September 1997 and November 1998, source water uptake was primarily from the upper soil profile while in March 1998, source water uptake was from deep in the soil profile. With few exceptions, we did not find striking differences in source water use between drought-hardy families and those that were locally adapted.     

Effects of biological soil crusts on profile distribution of soil water,organic carbon and total nitrogen in Mu Us Sandland,China

Aims Biological soil crusts (BSCs) can affect soil properties including water dynamics and cycling of soil carbon and nitrogen in dryland ecosystems. Previous research has mostly focused on effects of BSCs on soil water distribution or carbon and nitrogen fixation in the surface soil layer. Thus, little is known about effects of BSCs on properties throughout the soil profile. In the current study, we assessed the effects of BSCs on the distribution of soil water content (SW), soil organic carbon content (SOC) and soil total nitrogen content (STN) throughout the soil profile as well as the influence of water conditions on the effects of BSCs.Methods In a field investigation in Mu Us Sandland, North China, soil samples were taken from plots with and without BSCs on 13 and 28 September 2006, respectively. On the two sampling dates, average soil gravimetric water content was 3.83% (±1.29%) and 5.08% (±0.89%), respectively, which were regarded as low and high water conditions. Soil samples were collected every 5 cm to a depth of 60 cm, and SW, SOC and STN were measured in the laboratory.Important findings (i) BSCs affected profile distribution of SW, SOC and STN. In addition, water conditions within the plots significantly modified BSCs' effects on the profile distribution of SW, but marginally affected the effects on SOC and STN. (ii) Under high water conditions, SW in the surface soil layer (0–10 cm) was higher in soils with BSCs compared to those without BSCs, while the opposite was true in the deep soil layer (30–55 cm). (iii) Under low water conditions, SW was lower with BSCs compared with no BSCs in near-surface (5–20 cm) and deep (25–40 cm) soil layers. (iv) BSCs affected SOC and STN only in the surface soil layer (0–5 cm) and were modified by plot water conditions.     

冻融期去根处理对小兴安岭6种林型土壤微生物量的影响

春季冻融期,在小兴安岭的阔叶红松(Pinus koraiensis)林、谷地云冷杉(Picea koraiensis-Abies nephrolepis)林、阔叶红松择伐林、白桦(Betula platyphylla)次生林、红松人工林、兴安落叶松(Larix gmelinii)人工林的去根处理样地和对照样地进行野外取土实验,分析了根去除对上述林型土壤微生物量的影响以及与土壤环境因子的关系。结果表明:冻融循环期间对照样地和去根处理样地的林型、土壤层次、取样时间均显著地影响土壤微生物量碳(MBC)(P0.05),对照样地中各林型的土壤微生物量氮(MBN)差异显著,而去根处理样地中各林型的MBN没有显著差异(P0.05);冻融循环期间去根处理显著地减少了大部分林型及土层(谷地云冷杉林0—10 cm及择伐林外)的MBC,而去根处理对大部分林型及土层(阔叶红松林0—10 cm,谷地云冷杉林和择伐林的10—20 cm除外)的MBN没有显著影响。说明在小兴安岭春季冻融期根系对土壤微生物量的影响不可忽视。     

Managing ski resorts to improve biodiversity conservation: Australian reptiles as a case study

Alpine/subalpine environments are diverse systems that support many endemic species. Worldwide, these ecosystems are under threat from ski resort disturbances – even in areas broadly designated for biodiversity conservation. The effects of ski resorts on reptiles are largely unknown, making it difficult to implement effective conservation actions. Many ski resorts do not currently address the needs of reptiles, even those listed as threatened, in their management plans. If reptiles are to continue inhabiting ski resorts in Australia, strategies must be implemented that target their conservation. To begin to address this problem, we summarise current research investigating the effects of ski resorts on reptiles. Based on this information, we recommend strategies that will enhance the conservation of reptiles in areas affected by ski‐related disturbances. Suggested strategies include (i) restricting intensive disturbances to already highly modified areas of Australian ski resorts, (ii) avoiding disturbance of remaining native vegetation and structural complexity in ski resorts and (iii) re‐establishing structural complexity at highly modified sites through revegetation programmes, or through the cessation of mowing during peak reptile activity periods. While these strategies are designed to facilitate the persistence of reptiles in ski resorts, their long‐term success can only be evaluated by monitoring their effectiveness.     

冲积平原区高程因子对土壤剖面质地构型的影响--以封丘县为例

河流冲积平原区土壤剖面质地构型对土壤水肥保持、供给能力以及水盐运动产生极为重要的影响。区域土壤的六大成土因素中,地形的影响最为突出。分析土壤剖面质地构型的地形影响,对于指导农业生产具有重要的理论与现实意义。本研究应用模糊c-均值算法模型,基于土壤剖面特征质地层厚度数据,得到研究区9种土壤剖面质地构型。对比分析典型区和研究区土壤剖面质地构型的地形影响结果表明：隶属于土壤剖面质地构型砂-砂-砂的隶属度值与高程之间始终存在正相关,说明地形较高部位发育的土壤质地偏砂的规律性始终存在,而从典型区到研究区,其它土壤剖面质地构型、0-60cm土层质地类型、以及表土层、心土层和底土层质地类型受地形影响的规律性减弱。地形较低部位发育的土壤剖面质地构型相对复杂,而地形较高处,发育的土壤剖面质地构型相对简单。土壤剖面质地构型复杂的地区可能更多地受到人为因素的干扰,从而表现出受地形影响的规律性不明显。     

Effect of ski boot settings on tibio-femoral abduction and rotation during standing and simulated skiing

Ski boots are designed to transfer high forces from the skier to the ski. For this purpose they are made of stiff materials and constrain the leg of the skier to an unnatural position. To overcome the problem of unnatural knee posture, the ski boots can be adjusted in the frontal plane as well as in the horizontal plane by the canting mechanism and the "v-position", respectively. Canting enables lateral and medial orientation of the shaft with respect to the base of the boot. The "v-position" is a pronounced outward rotation of the boot's base with respect to the ski's long axis. The purpose of this study is to investigate the effect of different foot rotations and ski boot canting settings on knee kinematics during standing and simulated skiing. Knee kinematics was measured by means of motion analysis and with the help of skin-mounted markers on 20 subjects. The ski boots in their standard settings significantly constrained the skier to an unnatural valgus position. Ski boot base rotation had a significant effect on internal external knee rotation, whereas canting had an effect on varus-valgus angles during standing. However, for the simulated skiing position no effects were observed. The study suggests that the constraints of the ski boots result in a clinically relevant valgus misalignment. Canting settings reduced the misalignment but only by about 10%. Increased ski boot canting settings would therefore be desirable. Knee kinematics showed that rotational misalignment could not be linked to any significant increase in injury risk.