Spatial patterns of vegetation arise from an interplay of functional traits, environmental characteristics and chance. The retreat of glaciers offers exposed substrates which are colonised by plants forming distinct patchy patterns. The aim of this study was to unravel whether patch-level landscape metrics of plants can be treated as functional traits. We sampled 46 plots, each 1 m × 1 m, distributed along a restricted range of terrain age and topsoil texture on the foreland of the Nardis glacier, located in the South-Eastern Alps, Italy. Nine quantitative functional traits were selected for 16 of the plant species present, and seven landscape metrics were measured to describe the spatial arrangement of the plant species’ patches on the study plots, at a resolution of 1 cm × 1 cm. We studied the relationships among plant communities, landscape metrics, terrain age and topsoil texture. RLQ-analysis was used to examine trait-spatial configuration relationships. To assess the effect of terrain age and topsoil texture variation on trait performance, we applied a partial-RLQ analysis approach. Finally, we used the fourth-corner statistic to quantify and test relationships between traits, landscape metrics and RLQ axes. Floristically-defined relevé clusters differed significantly with regard to several landscape metrics. Diversity in patch types and size increased and patch size decreased with increasing canopy height, leaf size and weight. Moreover, more compact patch shapes were correlated with an increased capacity for the conservation of nutrients in leaves. Neither plant species composition nor any of the landscape metrics were found to differ amongst the three classes of terrain age or topsoil texture. We conclude that patch-level landscape metrics of plants can be treated as species-specific functional traits. We recommend that existing databases of functional traits should incorporate these type of data.

Ecological assessing of forest edges: comparison of two methods In Switzerland, forest edges are mostly man-made. Potentially, forest edge ecotones are very rich in species. In agricultural landscapes, they are also the main element of ecological connectivity. Unfortunately, today's forest edges are mostly far too narrow and monotonous to optimally fulfil their role. Some years ago, therefore, the federal government started a programme to improve the ecological quality of forest edges. Of course, the impact of the programme should be monitored and several assessment methods were developed. In the present paper, we compared the assessment methods of Pro Natura and Krüsi by applying them to eleven upgraded and three untreated forest edges. Even though both methods take into account the structure and the floristic richness of forest edges, they differ in many details. One major difference is that the Pro Natura method is based on estimates while the Krüsi method whenever possible relies on measurements. With both methods, it was possible to distinguish valuable from less valuable forest edges and, fortunately, the results of both methods even highly correlated. In conclusion, for a quick assessment by lay men, the rapid and simple Pro Natura method is recommended, whereas for scientific monitoring, the more reproducible and more sophisticated but also more time-consuming Krüsi method is more suitable.

Upgrading of forest edges: impacts of orientation and site fertility Wide, species-rich forest edges are rare in Switzerland. For some years now, the ecological improvement of forest edges has therefore been encouraged by the federal government. In order to make optimal use of the limited resources, we need a good knowledge of the site factors that influence the success of upgrading treatments. We studied 48 improved forest edges in Canton Aargau to understand the impacts of orientation and site fertility on the success of the improvement measures. The results showed that both orientation and site fertility had a significant impact on the quality of the enhanced forest edges. On south-facing and nutrient-poor sites, the ecological quality of the improved forest edges was significantly better than on nutrient-rich sites oriented towads other directions. On sites which were not south-facing fertility had no significant effect on the ecological quality of the improved forest edges. On nutrient-poor sites, the risk that problematic or invasive plant species become dominant after upgrading treatments was much smaller than on nutrient- rich sites. The orientation of the forest edge, on the other hand, had no significant effect on that risk. In the future, therefore, forest edge enhancement projects should preferably be carried out on south-facing and nutrient-poor sites. On sites with other expositions or with high fertility, successful upgradings are less likely but not impossible.

The role of oak, deadwood and ivy for habitat selection of the middle spotted woodpecker Due to their habitat needs, woodpeckers are generally considered to be excellent indicators of forest habitat quality and biodiversity. In the EU and in Switzerland, the middle spotted woodpecker acts as a flagship species for nature conservation in forests. After several decades of decline in the Canton of Zurich, the population of the indicator species more than doubled between 2002 and 2012. The reasons for this positive development are so far unknown. It is hypothesized that an increased availability of ivy berries, sometimes eaten by the middle spotted woodpecker, may have contributed to the population growth. Based on the woodpecker monitoring 2012 in the Canton of Zurich, in 2013 the availability of trees with ivy berries at sites with and without presence of the middle spotted woodpecker was examined in eight forests. At the same time we also studied the availability of oaks and standing dead trees, two habitat factors well known to be important for the middle spotted woodpecker. Results revealed significantly shorter distances to large oaks and a tendency towards shorter distances to dead trees at points with middle spotted woodpecker presence than at points without. The distance to trees with ivy berries, on the other hand, was the same at presence and absence points. Occurrence probability of the middle spotted woodpecker was best explained by the distances to the closest large oak and to the closest standing dead tree, respectively. The importance of ivy contributing to the structural diversity in forest ecosystems and providing food and refuge to many species is widely recognized. Therefore, ivy should not be eliminated and oaks and dead trees should be continued to be fostered.

Capsule The occurrence of the Middle Spotted Woodpecker in northern Switzerland was related to the availability of large oaks and standing dead trees, but not to trees with fruiting Common Ivy.

The calcifuge rock-dwelling fern Asplenium septentrionale is rare on the Swiss Plateau and in the Jura region, where it exclusively inhabits siliceous erratic boulders. A historical scientific debate on the origin of A. septentrionale on erratic boulders – transportation during the ice ages by glaciers on erratic boulders vs. post-glacial long-distance colonization – underlines the importance of those populations for science history. In the present study, a census of A. septentrionale on erratic boulders on the Swiss Plateau and in the Jura region was conducted, since only little is known about the current distribution of these biogeographically remarkable populations. We reviewed herbaria and literature and revisited locations. In total, historical records from 17 populations were found. Of these, five were confirmed, four were extinct, and the status of eight further populations remained uncertain, because the records were not accurate enough to allow the exact erratic boulders to be found. Two well-documented recent populations in the canton of Zurich showed a decline in population size over the last 100 years. Only 72 individuals were found in total. Destruction of erratic boulders for construction and collection for herbaria were significant historical threats, while shading by vegetation and sport climbing (bouldering) are contemporary threats today. On the Swiss Plateau and in the Jura region, regionally rare lichen and bryophyte species unique to siliceous erratic boulders would also profit from conservation measures for A. septentrionale.

Conservation tillage (CT) is widely considered to be a practice aimed at preserving several ecosystem functions. In the literature, however, there seems to be no clear pattern with regard to its benefits on species diversity and species composition. In Northern Italy, we compared species composition and diversity of both vascular plants and Carabids under two contrasting tillage systems, i.e., CT and conventional tillage, respectively. We hypothesized a significant positive impact of CT on both species diversity and composition. We also considered the potential influence of crop type. The tillage systems were studied under open field conditions with three types of annual crops (i.e., maize, soybean, and winter cereals), using a split-plot design on pairs of adjacent fields. Linear mixed models were applied to test tillage system, crop, and interaction effects on diversity indices. Plant and Carabids communities were analyzed by multivariate methods (CCA). On the whole, 136 plant and 51 carabid taxa were recorded. The two tillage systems studied did not differ in floristic or carabid diversity. Species composition, by contrast, proved to be characteristic for each combination of tillage system and crop type. In particular, CT fields were characterized by nutrient demanding weeds and the associated Carabids. The differences were especially pronounced in fields with winter cereals. The same was true for the flora and Carabids along the field boundaries. For studying the effects of CT practices on the sustainability of agro-ecosystems, therefore, the focus should be on species composition rather than on diversity measures.

(1) The survival of peripheral populations is often threatened, especially in a changing environment. Furthermore, such populations frequently show adaptations to local conditions which, in turn, may enhance the ability of a species to adapt to changing environmental conditions. In conservation biology, peripheral populations are therefore of particular interest. (2) In northern Switzerland and southern Germany, Libelloides coccajus is an example of such a peripheral species. (3) Assuming that suitable oviposition sites are crucial to its long-term survival, we compared oviposition sites and adjacent control plots with regard to structure and composition of the vegetation. (4) Vegetation structure at and around oviposition sites seems to follow fairly stringent rules leading to at least two benefits for the egg clutches: (i) reduced risk of contact with adjacent plants, avoiding delayed drying after rainfall or morning dew and (ii) reduced shading and therefore higher temperatures. (5) Furthermore, the study showed that it is possible to successfully create secondary habitats for L. coccajus , as shown by a road verge in one of our study areas. It is likely that other artificial habitats such as abandoned gravel pits and quarries may also provide suitable habitats.

20 years of ecological forest edge enhancement in the Canton of Aargau: a first evaluation On the Swiss Plateau, 25 000 km of forest edges serve as transition zones between open grasslands and closed forests. They fulfil important functions with regard to ecological connectivity and constitute a habitat for numerous plant and animal species. Since only a fraction of these forest edges are in good ecological condition, most cantons implement programs to enhance their quality. With almost 200 km of upgraded forest edges, the Canton of Aargau takes on a pioneering role throughout Switzerland. To date, however, it was unknown what ecological value the upgraded forest edges have and which factors significantly contribute to the success of the implemented measures. We used a standardised evaluation key and interviews with the responsible forest services to assess the ecological quality of 20 selected forest edges in six forest districts in the Canton of Aargau as well as potential success factors. Our investigations show that enhanced forest edges in the Canton of Aargau are in a very good condition. The two most important structural elements of a forest edge in terms of biodiversity are two to eight times more marked than on average on a national scale, and they nearly conform to the objectives as defined by nature conservancy. With a registered total of 31 domestic deciduous tree species and 58 domestic lignified plant species, floristic diversity is remarkably high. Contrary to the estimation of the responsible forest services, neither the vigour of a location nor its aspect proved to be decisive factors of success. Rather, the frequency of intervention seems to be critical. Maintenance measures should be implemented at least every seven years. More comprehensive analyses are necessary to corroborate the present findings for other regions in Switzerland. Precondition for such analyses are systematic performance reviews that include an examination of the baseline conditions.

The facilitative and competitive effects of shrubs on herbaceous species have been extensively studied, but little is known about the roles of the shrub distribution patterns in such effects. On a heavily grazed pasture on the Tibetan Plateau, we investigated the effects of Potentilla fruticosa Linn. shrubs of different distribution patterns on the small-scale vegetation pattern of the herb layer. We made same-sized releves at five micro-site types, i.e., beneath and outside the canopies of solitary Potentilla individuals, beneath and outside the canopies of edge-of-patch individuals and at the central openings of torus-shaped large Potentilla patches. Shrubs protected certain species by increasing their frequencies of occurrence or flowering. However, only few species benefited from shrubs and more occurred or flowered more frequently outside. The data at community level indicated that species richness and diversity index were higher outside. The patch openings did not benefit species richness, pooled cover, diversity index or evenness of central vegetations. No special species was found growing beneath shrubs exclusively and few species were found with higher occurrences beneath shrubs. Furthermore, no significant difference was found between the two different distribution patterns at either community or species level. Vegetation ordinations confirmed this and vegetations beneath and outside the shrubs were distinguished merely. In conclusion, Potentilla facilitated some species in the herb layer and the patch openings did not show large protective effects. Also, distribution patterns of Potentilla did not affect the difference between vegetations beneath and outside shrub canopies.

Tussocks of graminoids can induce spatial heterogeneity in soil properties in dry areas with discontinuous vegetation cover, but little is known about the situation in areas with continuous vegetation and no study has tested whether tussocks can induce spatial heterogeneity in litter decomposition. In a subalpine grassland in the Central Alps where vegetation cover is continuous, we measured soil properties [concentration of N, C, organic matter (OM) and pH] and monitored litter decomposition traits (dry mass loss, loss of C, N, P and K) inside and outside tussocks of Carex sempervirens. Soil C, N, OM concentrations or pH inside tussocks did not differ significantly from those outside tussocks. After 1 year of decomposition, litter dry mass loss, C and K loss were significantly smaller inside than outside tussocks. The slower litter decomposition inside tussocks was likely caused by the elevated tussock base, which made environmental conditions inside tussocks much dryer than those outside in early spring when snow melts. Our results suggest that in areas with continuous vegetation cover tussocks induce spatial heterogeneity in litter decomposition but not in soil properties.

As study area we selected the glacier foreland of Morteratsch (approx. 1900–2100m a.s.l.) near Pontresina northwest of the Bernina pass, Upper Engadine, Grisons (Switzerland). The aim of this study is a multimethodological approach using floristic inventories, vegetation and soil mapping of the pro-glacial area in order to detect crucial parameters controlling plant resettlement in recently deglaciated areas as related to time, local microtopography and soil development.

Abstract• Canarian Juniper woodlands, now very scarce, are rich in endemic and endangered plants. However, many aspects of juniper regeneration are almost unknown.• This paper relates occurrence and abundance of recruits of Juniperus turbinata ssp. canariensis to (1) small-scale soil characteristics; (2) vegetation cover; and (3) distance to conspecific adults in two contrasting juniper stands in the eastern mountains of Tenerife. We used non-parametric classification trees and generalised linear models (GLM) to evaluate the effect and importance of each explanatory variable on the occurrence of juniper saplings.• Sapling density, vitality and growth rate, as well as fruit production by adult trees, but neither cone density on the ground nor sapling size, varied significantly with respect to slope orientation, representing environmental stress. Within each stand, distance to nearest adult tree was the most important variable explaining the spatial distribution of juniper saplings and availability of seeds in cones. Additionally, saplings were positively associated with shrub cover at the microsite-level, but not with spiny shrub cover. Soil depth and rock cover had a weak negative effect on sapling establishment, but only at the south-facing site and in the open space microhabitat.• Results suggest that recruitment of Canarian juniper is facilitated by microhabitats offered by adults and shrubs. The key factors affecting recruitment are thought to be (1) favourable micro-environmental conditions and (2) high ambient seed availability. Browsing intensity in recent decades was very low. The presence of spiny shrubs did not favour juniper establishment. Facilitation therefore appears to result from amelioration of abiotic conditions rather than from protection against herbivory.

Synthesizing genetic data at population level and vegetation data at community level may give insight into how ecological and evolutionary processes associated with different vegetation influence genetic diversity and differentiation of plant populations. We correlated population genetic patterns of Carex sempervirens with community vegetation patterns in abandoned subalpine grassland in the Swiss Alps. Within-population genetic diversity (percentage of polymorphic bands and Nei's gene diversity) of C. sempervirens was not significantly correlated with plant richness, evenness or Shannon's diversity index (Pearson correlation coefficient |r|<0.32, P>0.10). However, the genetic distance (FST) between C. sempervirens populations was significantly positively correlated with the vegetation dissimilarity between communities (Mantel's r=0.23, P<0.01). The correlation between the population genetic differentiation and the vegetation dissimilarity was not due to the parallel effects of geographic isolation or site conditions, because FST was not correlated with the geographic distance or the pairwise differences in any of the measured site condition parameters. One likely mechanism is that different plant communities were associated with different selective forces, which, in turn, influenced the genetic differentiation between C. sempervirens populations. Another possibility is that the vegetation heterogeneity (dissimilarity) generated ecological barriers against gene flow and thus enhanced the genetic differentiation between C. sempervirens populations.

The species-area relationship (SAR) has been extensively studied in a wide range of plant communities, but very few studies have directly addressed how plant communities affect the SAR and what are the underlying mechanisms. Many graminoids form distinct tussocks where many other plant species grow, but no study has investigated whether the SAR holds true for the vegetation on tussocks. In four plant communities on an abandoned subalpine pasture in the Swiss National Park, we made releves on 600 tussocks of Carex sernpervirens and measured tussock basal area and other tussock traits. In all four communities, species richness on C sempervirens tussocks was strongly positively related to tussock basal area (R-2 >= 0.74), while other tussock traits explained very little (R-2 < 0.04). Slope and intercept of the SAR on C sempervirens tussocks differed significantly among the four communities. This was because plant communities affected richness in smaller tussocks (basal diameter < 10 cm) but not that in large tussocks (basal diameter >= 10 cm). We conclude that the SAR holds true for vegetation on C sempervirens tussocks and changes with plant communities. Changes in the SAR on C sempervirens tussocks are very likely because smaller tussocks are less independent of the plant communities than the larger ones, regarding disturbance or nutrients. (C) 2008 Elsevier GmbH. All rights reserved.