Caddisfly assemblages of high mountain streams (The High Tatra Mts, Slovakia) influenced by a major windstorm event

Hydrobiological research of high mountain streams in the High Tatras was carried out in 2009–2010. We evaluated the influence of windstorm on caddisfly assemblages. To assess the influence of windstorm we focused on river morphology using the RHS method and evaluation of TAM, TOM and BOM (CPOM, FPOM, UFPOM) amount in seven streams. Site 1 was a control and the other six were disturbed by the windstorm in different ways. The most remarkable differences compared to the control site was in feeding structure at sites most affected by erosion. In these streams there was a noticeable dominance of predators from the family Rhyacophilidae (mainly Rhyacophila tristis; sites 3, 4, 5, 6) and a remarkable decrease of passive filter feeders (site 4, 5). Using Spearman coefficient we confirmed a positive correlation between the proportion of predators and amount of TAM caused by erosion of steep deforested slopes of windstorm affected sites. In contrast, we did not observe such an increase in the proportion of predators at site 7, which was affected by both windstorm and subsequently by fire. This might be explained by the shallow vee valley with no observed erosion, where this site is situated. We also found a negative correlation between predators and evenness, indicating unstable community structure clearing succesion in the streams disturbed by erosion, and a negative correlation between passive filter feeders and UFPOM. We found out that overhanging tree boughs and LWD had an influence on species composition. RHS was a useful tool in characterising the influence of hydromorphology on caddisfly assemblages.     

The influence of environmental variables on larval growth of stoneflies (Plecoptera) in natural and deforested streams

A total 14 streams located in the Tatra Mts (Slovakia) were investigated. The studied river basins have different deforestation range (0–45.5%) influenced by windstorm. Daily and annual water temperature suggested that in streams overflowing through the area deforested by windstorm the temperature was higher than in selected non-disturbed streams. Higher average nutrient concentrations in samples from these streams are connected with nutrient mobilization from disturbed forest soils after the windstorm. Most of the damaged streams have higher trophic status, including POM and biofilms. The growth of the most abundant larvae increases with deforestation. Growth of species Leuctra rauscheri, Protonemura Montana, and Perlodes intricatus correlates with the sum of daily temperatures over a given time interval. Growth of species Brachyptera seticornis, Leuctra autumnalis and Isoperla sudetica are affected by stream trophy.     

Does environmental disturbance also influence within-stream beta diversity of macroinvertebrate assemblages in tropical streams?

Riparian deforestation is a major threat to the ecological integrity of streams and aquatic biodiversity, influencing microhabitat availability and susceptibility to disturbances. Here we tested if riparian deforestation of tropical streams influenced beta diversity of macroinvertebrate assemblages, by comparing indices that weighted differentially rare and dominant taxa, and testing if nestedness in community composition increased in deforested streams. Within-stream beta diversity was higher in deforested than forested streams, mainly due to taxon loss and higher dominance. In disturbed streams, higher sedimentation in pool mesohabitats resulted in larger differences in community composition, whereas mesohabitats in forested streams were more stable.     

Caddisflies (Trichoptera) as good indicators of environmental stress in mountain lotic ecosystems

We analysed the influence of environmental stress (mainly deforestation of catchment due to windstorm) on taxonomic structure as well as composition of functional groups (FG) based on zonation preferences and feeding types of caddisfly species in 11 streams (12 sites) with various environmental conditions situated in the High Tatra Mts, Slovakia. Using Spearman correlation, we confirmed an expected positive association between taxonomic and functional groups richness (Ri), diversity (Shannon — Wiener Index) (Di) and equitability (Eq), but not with habitat diversity (HQA indices). By testing measured physiographical, physico-chemical and hydromorphological factors using CCA analysis we found that stream order and temperature best explained the functional and taxonomic structure of caddisfly assemblages. The occurrence of Rhyacophila glareosa decreased with increasing daily mean water temperature positively correlated with deforestation, whereas R. tristis (dominating at sites most affected by erosion) showed the opposite pattern. Composition of functional groups based on zonation preferences and feeding types distinguished well near natural sites from impacted ones, dominated by crenal/rhithral predators, and explained more of the overall variance of the species-environment relationships than taxonomic composition of caddisfly assemblages.     

Late Holocene vegetation history suggests natural origin of steppes in the northern Mongolian mountain taiga

Insular occurrences of steppe vegetation are a common feature of the northern Mongolian mountain taiga. Steppe vegetation is limited here to southern slopes, whereas northern slopes and valley bottoms are principally wooded with light and dark taiga forests. In a case study in the valley of the river Eroo at Khonin Nuga Research Station in the western Khentey Mountains, we searched for evidence of an anthropogenic versus natural origin of steppe vegetation on the southern slopes. Pollen data of three profiles covering the last 2500 years showed continuous presence of steppe throughout the late Holocene with human influence restricted to the recent past. Virtual absence of charcoal in the soil on and beneath three steppe slopes suggested that the present steppe grasslands are not replacing former forests burnt by humans or lightning. The floodplains in the center of the Eroo valley were recently deforested. This is suggested by the pollen analysis and by interviews with local people on landuse history. Steppe grasslands of the study area have probably never been used as pastures. Pastoral nomads traditionally avoided the Eroo valley near Khonin Nuga because of difficult access and high densities of wolves and bears. All our data suggest that the present vegetation pattern of the western Khentey with steppes (and single small Ulmus pumila trees) on south-facing slopes occurring as islands in the mountain taiga is driven by climate and relief and is not the result of human activities as suggested for other regions of Asia.     

Ecological significance of polyploidy in high mountain plants and plant communities

The frequency of diploids and polyploids in the flora and plant communities of the Temnosmre?inová dolina valley (High Tatras) and the valley dolina Siedmich prameňov (Belianské Tatry mts.) is discussed in connection with environmental conditions and life forms.     

Vegetation coverage,species richness,and dune stability in the southern part of Gurbantünggüt Desert

This study investigated the relationship between vegetation coverage, species richness, and environmental factors, and also analyzed the relationship between vegetation coverage, species richness, and dune stability in different terrains, in the southern part of Gurbantünggüt Desert in China. The results showed that the order of vegetation coverage and species richness was greatest in middle areas, followed by the eastern areas, with the western areas being sparse. On a large scale, precipitation from April to June determined the amount of vegetation coverage. On a small scale, vegetation coverage was influenced by the type of terrain and the water and salt content in soils. Species richness of vegetation was determined by soil water and salt content on both the large and small scales. There were also remarkable differences in relative wind erosion among the different terrains and their order was: crest, slope, and inter-dune in descending order. The correlations between wind erosion and vegetation coverage and species richness were influenced by the type of terrain. Furthermore, there were significant correlations between wind erosion and vegetation coverage and species richness in dune slopes and crests. There was, however, no significant correlation between wind erosion and vegetation coverage and species richness in inter-dune sites. Vegetation coverage was the dominant factor influencing wind erosion in both slopes and crests. Species richness may have an impact on wind erosion through vegetation coverage in both slopes and crests. These results suggest that the effect of terrain type should be fully considered during the establishment of vegetation cover in the desert.     

Benthic diatoms as indicators of eutrophication in tropical streams

Diatoms are frequently used as indicators of eutrophication in temperate systems, but little is known about their application to impacted African tropical systems. Five streams located within Gombe Stream National Park and five streams supporting human settlements draining into Lake Tanganyika, East Africa, were investigated for species composition, richness and diversity of epilithic algae. In addition, a trophic diatom index (TDI) developed for monitoring European rivers was applied to these tropical systems. 54 specific and infraspecific diatom taxa representing 20 genera were identified for all sites with Achnanthes s.l., Gomphonema and Navicula s.l. being the most common genera. Species richness varied between 10 and 21 in disturbed streams and 13 and 19 in undisturbed streams. Nutrients were significantly enriched in streams draining the deforested watersheds but indices of diversity and evenness (Shannon H, J and Simpson–Yule D, E) did not show any significant differences between streams in forested and deforested watersheds. Significant differences were observed between pooled data for the TDI between forested and deforested watersheds. Analysis of percent pollution tolerant diatom taxa indicates that organic pollution of streams in deforested watersheds may be contributing to eutrophication. This study shows that African diatoms, cosmopolitan or resembling well-known North American and European taxa, allows for trophic indices tailored to the autecological preferences of species to be applied to new regions, although intensive studies on these African taxa will lead to more accurate results. Measures of species-richness and diversity, historically used to describe the state of an ecosystem, may not be suitable to evaluate streams which are not grossly polluted. Electronic supplementary material Electronic supplementary material is available for this article at and accessible for authorised users.     

Vegetation structure in relation to micro-landform in an evergreen broad-leaved forest on Amami Ohshima Island,south-west Japan

The relationship between micro-landform and vegetation structure was studied in a plot that was established on a slope from the ridge to the valley bottom in an evergreen broad-leaved forest on Amami Ohshima Island, south-west Japan. Five micro-landform units recognized in the plot were grouped into the upper and lower slopes by their location in relation to the erosion front, and plant distributions and vegetation structure were compared between them. Although small trees with d.b.h. less than 10 cm occurred almost all over the plot, the occurrence of larger trees was limited mostly to the upper slope. Based on the spatial distribution pattern in the plot, woody species are classified into three groups: group A mostly or strictly confined to the upper slope; group B confined to the lower slope; and group C associated statistically with neither slope. A well-developed forest stand, whose dominant species wereCastanopsis sieboldii ssp.lutchuensis andSchima wallichii, was seen on the upper slope, whereas only a poorly developed stand was seen on the lower slope. The difference in stability of the land surface is likely to be the major cause of the observed differences in stand structure between the upper and lower slopes. It is suggested that the erosion front is important as a line demarcating different habitats within a slope from the ridge to the valley bottom.     

Relationships among microclimate,edaphic conditions,vegetation distribution and soil nitrogen dynamics on the Bogong High Plains,Australia

We examined microclimatic conditions and soil nitrogen (N) dynamics of different alpine plant community types on the Bogong High Plains in Victoria, Australia. Three community types are predominant in the High Plains region, namely grassland, heathland and woodland and together they form so‐called inverted treelines, with grassland in valley floors below the treeline. Outdoor temperature loggers were deployed in the three vegetation types to establish differences among microclimatic conditions. We incubated soils to determine rates of N production and collected additional soil samples for analysis of soil properties and soluble N. Temperature data showed that only grassland communities experienced sub‐zero temperatures in winter. Temperature and soil moisture influenced indices of N mineralization and N nitrification in this alpine ecosystem. Rates of N mineralization were significantly faster than nitrification that only produced consequential amounts of nitrate in summer. This information, together with considerably lower pools of nitrate than ammonium and organic N in the soil, implies that ammonium is the dominant form of soluble N in the ecosystem whereas nitrate most likely only has minor importance for plant nutrition. The results of this study provide insight into ecological processes of this alpine ecosystem and demonstrate the vulnerability of the system to altered climatic and edaphic conditions in the course of climate change.     

Lung nematodes of chamois, Rupicapra rupicapra tatrica, from the Tatra National Park, Slovakia.

A larvoscopic examination of faeces collected from localities inhibited by chamois in the Tatra National Park (TANAP) in 1997 demonstrated the presence of the lung nematodes Muellerius spp. (likely to be M. tenuispiculatus and M. capillaris) and Neostrongylus linearis. The overall prevalence of lung nematodes in chamois herds in TANAP was 48.4% with prevalences of 45.6% and 11.9% for Muellerius spp. and N. linearis, respectively. No significant differences in lung nematode prevalences were observed in the biotopes of TANAP with prevalence values of 44.9% being recorded in the High Tatras and 58.5% in the Belianske Tatras. Individual species were in equal proportion in both biotopes, although N. linearis was significantly less prevalent (11.2-13.8%). The prevalence of lung nematodes in the High Tatras varied from 25.0 to 84.2% within individual localities, while in the Belianske Tatras it was more proportionate (50.0-85.7%). In the High Tatras, the prevalence of lung nematodes in the chamois herds peaked during August, declining to its lowest in October. A similar prevalence was also recorded for Muellerius species, while the minimum prevalence of N. linearis was found in July. In the Belianske Tatras, the prevalence of lung nematodes including both species of Muellerius peaked in July and gradually decreased until October. On the other hand, N. linearis was most prevalent in October. The mean L1 count per gram faeces was low (7.6 +/- 13.2 larvae g-1).     

Changes on Streambanks in the Sierra Nevada Mountains: Perspectives from a Dry and a Wet Year

We summarize the findings of a two-year study of vegetation and streambank erosion on incised streams. We conducted the first year of the research during the sixth year of a drought. During the second year of study, precipitation totals ranged from normal to 200% of normal. The focus of the study was to determine if vegetation established on a bank affects the erosion of or deposition on that bank. During the drought year, most banks showed relatively little change. During the high water year, 27% of all vegetated and 32% of all bare lower banks retreated more than 250 mm. This similarity between vegetated and unvegetated banks indicates that, on the streams studied, vegetation had little effect on bank erosion. Bank retreat was not related to near-bank velocities or to bank steepness. It is possible that herbaceous vegetation showed no effect on the incised streams because the streams were too far from a new dynamic equilibrium. The energy of the hydraulic system may have been greater than the vegetation could withstand.     

Performance of Vegetation in Reclaimed Slopes Affected by Soil Erosion

Soil erosion in reclaimed mines may affect plant colonization and performance, and may compromise restoration success; however, the magnitude of this effect has seldom been quantified. We monitored the dynamics of vegetation (seed bank density, seedling emergence, plant mortality, and seed production) during a growing season (2003–2004) in three constructed slopes with differing past erosion rates. The slopes are located in the Utrillas coalfield in Spain, which experiences a Mediterranean‐continental climate. In the most eroded slope, soil water availability was lower—especially in the interrill areas—and seedling emergence rate, plant survival, and seed production were also significantly lower than on the less eroded slopes. We found that vegetation recovery is dramatically constrained when rill erosion rate is 17 t ha^?1 yr^?1 and plant cover is 30%, but this effect disappears when plant cover is higher than 60%. Soil erosion in constructed slopes appears to inhibit natural plant colonization processes by increasing runoff water loss over the long‐term. Thus, when rill erosion networks develop, human intervention would be needed to minimize the loss of water and facilitate vegetation colonization.     

Principles of planning and establishment of buffer zones

Good management of the uplands is essential and effective buffer zones along the streams draining the basin will complete the task of water quality protection. Most basin drainage moves through the riparian zones of first- and second-order headwaters streams. It is important to have continuous buffers on both sides of these streams. For larger streams, protect the flood plains. Several zones of buffer vegetation are most effective. A narrow grass strip at the upland edge traps suspended particulates and phosphorus. A wider zone of woody vegetation traps nitrate, and both cools and provides natural organic matter to the receiving waters. Contour the buffer surface to avoid concentrated storm flows and periodically remove sediment berms that develop. For a completely degraded riparian zone, it is essential to provide soils of the right porosity and organic carbon content. Sub-soils need to be permeable and to have a reasonable groundwater retention time. High organic carbon is required to develop a low redox potential. Provide short-term protection from erosion. Only add native species. Sometimes, exotic plants get established and must be eradicated. Fence livestock out. Control excessive activity by wild ungulates, voles, and beaver.     

南亚热带水土流失地区人工加速植被演替过程

水土流失地区植被在自然条件下从阳生草本到乔灌草复合植被的演替过程常常需要很长的时间,选取适当树种人工造林可以省略先锋物种强阳生草本的发育时间,提早诱发灌木和草本植物发育,大大加速植被恢复演替过程。通过对广东惠州市惠阳区上杨试验站等南亚热带典型水土流失地区的研究发现：自然封育状态下,水土流失地区植被恢复和演替缓慢,25。后植被覆盖度只有35％,且主要以阳生性耐贫瘠的灌木及草本为主,土壤侵蚀仍然比较严重。选择大叶相思树人工造林加速了植被演替进程,控制了水土流失,12a左右植被覆盖度就达90％左右。造林23a左右,林地遮蔽涵养水分和控制侵蚀作用下迅速生长多种当地物种,形成了乔、灌、草、藤、竹多层复合植被。在南亚热带季风气候地区,自然封育状态下严重水土流失区植被恢复至较稳定的次生林阶段需要60a左右的时间;人工造林加速植被演替只需要20a。植树造林是该地区植被恢复发育及控制水土流失的有效措施。     

Ecotones and fluvial regimes in arctic lotic environments

The fluvial regime in arctic streams is influenced by size of stream, the presence and storage capacity of lakes in the drainage basin, groundwater, and permafrost. Exchange of material with terrestrial environments depends on the season and is more or less suspended in winter. Permafrost and water storage in ice and snow control run off and erosion. Damage to vegetation by flooding, fire, animal or human activity can affect the permafrost and result in rapid erosion. Living space and conditions in lotic environments are modified by ice and during break up are very labile. Fish and benthic organisms in streams have behavioural and physiological adaptations which allow them to benefit from the wide range of river and stream environments found in the arctic and to tolerate the range of seasonal conditions. Ecotones are weakly developed in arctic streams and are of minor functional significance. Only farther south does riparian vegetation begin to play a role in regulating stream processes and not until south of the tree line can ecotones be considered important modulators of fluvial environments.     

Management and micro-scale landform determine the ground flora of secondary woodlands and their verges in the Tama Hills of Tokyo,Japan

We investigated the influence of management and micro-scale landform on the species composition and richness of ground flora in secondary woodlands and their verges next to paddy fields in the Tama Hills, Tokyo, Japan. Sites representing various micro-scale landforms and different management regimes were sampled. The results of Detrended Correspondence Analysis and Indicator Species Analysis showed that there was no significant difference between management regimes on species composition in head hollow sites. However, species composition was unique in other landform types having the same management regimes. Micro-scale landform units had less effect on species composition than management regime on crest slopes and side slopes of secondary woodlands. A large variation in species composition of verges, all on the lowermost side slopes, was found within sites, but the composition was different when compared with other sites. We recognized five habitat types associated with species composition that resulted from the combined effects of landform and management regimes. Among habitat types, the verges and the well-managed woodlands had high species richness. Management practices within woodlands have enhanced the species richness on crest slopes and side slopes. High beta diversity of ground flora could be due to the variation in micro-scale landform along soil moisture regimes. Intensive management involving clear-cutting on the lower side slopes (an ecotone of mesic and wet environments) accompanied by paddy cultivation on valley bottoms enhanced the diversity of herbaceous vegetation in the verges.     

Factors Controlling Vegetation Establishment and Water Erosion on Motorway Slopes in Valencia, Spain

In semiarid Mediterranean areas, the widespread environmental impact caused by the construction of motorways, railways, and pipelines has created an increasing need for effective restoration. We examined the influence of slope characteristics on vegetation and water erosion on 71 motorway slopes in a semiarid Mediterranean region. Specifically, we studied the effect of slope angle, type (roadfill vs. roadcut) and aspect (north vs. south) on soil properties, vegetation cover, species richness, floristic composition, and water‐caused erosion. Temporal dynamics of soil water content was monitored and related to the soil water potential in order to explain possible differences in vegetation cover between slope types. The main factors influencing vegetation on motorway slopes were the angle, type, and aspect of the slope. Vegetation was almost completely lacking on roadcuts with slopes greater than 45°. On gentler slopes, vegetation cover was 44–78% on roadfills but did not reach 10% on roadcuts, regardless of aspect. The main soil properties affected by the slope type and aspect were the organic matter content, soil available P, and water content. Rill erosion, gully erosion, and mass movement were all significantly higher on roadcuts than roadfills. A total of 308 spontaneous colonizers and seeded species were recorded. The type and aspect of the slope also controlled species composition. The short duration of available water in the soil with respect to soil water potential proved to be a limiting factor to plant colonization on roadcuts and south‐facing slopes as well as the low soil fertility in the case of roadcuts. Our results underscore the difficulty of revegetating slopes with angles greater than 45°, where the probability of seeds moving downhill is high. Future efforts should focus on increasing the surface roughness or building terraces at regular intervals in order to reduce slope angle to less than 45° and favor seed trapping and germination. On gentler slopes, adjusting of seed mixes according to dominant species associated with each slope type and aspect should improve considerably the success of roadside revegetation.     

乡土植物生活型构成对川渝地区边坡植被水土保持效益的影响

乡土植物灌木化建植是高速公路边坡防护的重要生态模式。为了探讨生态恢复过程中乡土植物的生活型构成对边坡植被水土保持效益的影响,揭示乡土植物生活型-物种多样性-生态系统功能间的偶合关系,借助3个物种配置试验,于2009年4月构建了以草本、灌木或乔木为主体的草本型、灌木型、乔木型绿化配置及草-灌-乔混合型试验区。自建植次年(2010年)起,对试验区进行持续5a生态监测。结果表明:1)边坡植被的物种丰富度与乡土植物的生活型有关,呈现乔木型灌木型草-灌-乔混合型草本型趋势;2)植被的物种多样性(Shannon-Wiener指数、Pielou指数)与乡土植物生活型构成及建植年限有关:建植后第1、第2年,多样性水平呈草本型草-灌-乔混合型灌木型乔木型变化趋势;自建植后第三起(2012—2014年),呈草-灌-乔混合型草本型灌木型乔木型波动;3)植被的水土保持性能(径流系数、侵蚀模数)与群落的物种多样性密切相关:多样性水平越高,水土保持性能越强。可见,乡土植物的生活型构成对提高边坡植被的物种多样性、改善生态性能至关重要。     

Preliminary testing of River Habitat Survey features for the aims of the WFD hydro-morphological assessment: an overview from the STAR Project

The UK River Habitat Survey (RHS) method for the assessment of hydro-morphological features was applied within the EU STAR project simultaneously with the collection of biological data. A subset of data from 79 sites affected by hydro-morphological alteration and belonging to 7 different stream types was analysed. The different features recorded within RHS were evaluated separately considering the characteristics associated with banks, channel and riparian zone. Different scores were assigned to selected features representing hydro-morphological alteration and naturalness of habitat. The ability of the different compartments to represent the quality gradient of sites was investigated. In addition, the link between macroinvertebrate community and hydro-morphological data was investigated, directly relating indices and metrics calculated from taxa list collected in a site to scores assigned to the RHS features. The sections highly affected by morphological alteration were channel geometry and bank profile. Metrics showing the best correlation with the features selected were EPT taxa, ASPT and ICMi (Inter-calibration Common Metric index). Among the indices studied, the HQA score (Habitat Quality Assessment) apparently played the most important role in structuring biological communities and the lentic-lotic character of rivers was also important. Electronic supplementary material Electronic supplementary material is available for this article at and accessible for authorised users.