How do biodiversity and conservation values relate to landscape preferences? A case study from the Swiss Alps

The importance of the values underlying different concepts of biodiversity conservation and landscape planning is increasingly recognised, and yet these value judgements of the public and of experts are still poorly understood. Although landscape and conservation management are closely interrelated and measures in one field are likely to have effects on the other, the relationship between biodiversity and conservation values on the one hand, and landscape preferences on the other hand, has been hardly explored so far. This study represents a first attempt to empirically examine this relationship from an integrated perspective, considering philosophical, ecological and economic aspects and using items focused on biodiversity. We used a quantitative survey of the general Swiss population with visualisations of potential landscape developments in the Swiss Alps and items related to biodiversity- and conservation-values. Our research shows that respondents who prefer reforested landscapes tend to be more concerned about the conservation of species, landscapes, and natural processes than people preferring cultural landscapes. Respondents who prefer cultural landscapes are more oriented towards utilitarian values and are overrepresented in mountain areas as compared to the lowlands, thus in areas that are more likely to become the target of conservation measures. Our findings have practical implications for conservation in Switzerland and other mountainous areas, particularly in times of agricultural decline and land abandonment and their associated changes in landscape and biodiversity.     

How do roads affect the habitat use of an assemblage of scavenging raptors?

Scavengers may benefit from the availability of dead animals along roads that result from collisions with vehicles. However, roads are also considered risky places for many species. Animal habitat selection patterns usually balance energy intake with mortality risk. In this work we analyzed the foraging space use of an assemblage of diurnal scavenging raptors in relation to distance from roads in northwest Patagonia. We selected patches at different distances from roads, and placed a sheep carcass in each patch during the night (n = 18 carcasses in total). In general, carcasses near roads were detected by diurnal scavenging raptors much faster than those far from roads. Smaller raptors such as southern caracaras (Caracara plancus), chimango caracaras (Milvago chimango), and black vultures (Coragyps atratus), were commonly associated with roads both in terms of overall detections and scavenging activities. Southern and chimango caracaras proved to be very good at detecting carcasses, were faster to land in order to feed from them, and were found in greater numbers near roads than far from them. Even though Andean condors (Vultur gryphus) and black-chested buzzard-eagles (Geranoaetus melanoleucus) flew all over the area, they chose to feed far from roads. Our work emphasizes that some scavengers have taken advantage of the novel food resources provided by roads whereas others are reluctant to feed near them. Within a scenario of an increasing number of roads, some species can extend their distributions favoring competition and biotic homogenization processes within original communities. We highlight the importance of taking into account large flying scavengers in land-use planning. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Living on the edge: do central and marginal populations of plants differ in habitat suitability?

The performance of populations at the edge of specie’s distribution range may differ substantially from central populations. Here, we develop a modelling framework to estimate ecological niches (i.e. climatic) of four locally endangered plant species and measure the distance of marginal (geographically) populations to the species’ niche centroid in order to analyse whether marginal populations are outside of the optimal ecological niche of each species. Our results show that for three of the four studied species, which have their populations located at the margins of their distribution ranges, are also at the margins of their climate gradients. These results would support the hypothesis that marginality within the set of habitable conditions (i.e. ecological niche) may represent an important determinant on performance of some plant populations, as well as a plausible explanation to the degree of stagnancy or regression experienced by species in those regions where their populations are at the margin of their ecological niche and/or they are restricted to microrefugia with ecological conditions very different from those around them. Finally, this study aims to be a theoretical base from which to advance on, including other types of factors (e.g. biotic interactions, topography, human influence and population fluctuations through time), which will allow for a better understanding of the complex network of factors that occur in marginal plant populations.     

How do plants feel the heat?

In plants, the heat stress response (HSR) is highly conserved and involves multiple pathways, regulatory networks and cellular compartments. At least four putative sensors have recently been proposed to trigger the HSR. They include a plasma membrane channel that initiates an inward calcium flux, a histone sensor in the nucleus, and two unfolded protein sensors in the endoplasmic reticulum and the cytosol. Each of these putative sensors is thought to activate a similar set of HSR genes leading to enhanced thermotolerance, but the relationship between the different pathways and their hierarchical order is unclear. In this review, we explore the possible involvement of different thermosensors in the plant response to warming and heat stress.     

How do misassigned paternities affect the estimation of heritability in the wild?

Studies of birds have recently played an important role in the increasing success of quantitative genetics applied to natural populations. However, these studies mostly base their pedigree relationships on social information, despite the known widespread genetic polygamy in avian species. Here, we study the influence of misassigned paternities, combined with the effect of pedigree size and depth, on the estimation of heritability. First, we compute simulations of a polygenic trait for two levels of heritability (0.1 and 0.4), several extra-pair paternity rates (ranging from 5% to 40%), and varying sample sizes (20, 50 and 100 broods) or pedigree depth (2 or 4 generations). We compare heritability estimates from the social and the genetic pedigree, running a restricted maximum-likelihood 'animal model'. Social pedigree underestimates heritability by an average of 0-17% for 5-20% extra-pair paternities and by up to 18% for 40% extra-pair paternities and a heritability of 0.4. Second, we identifyied extra-pair offspring using microsatellite loci in two populations of blue tits (Parus caeruleus) showing high levels of extra-pair paternities (15% and 25% of extra-pair offspring). We compare heritabilities of tarsus length and body mass estimated with pedigrees of increasing accuracy. These analyses suggest that the bias induced by misassigned paternities on heritability estimation depends on the level of heritability and the rate of paternity error. Typical rates of extra-pair paternities in birds (around 20% of offspring) should result in an underestimation of heritability of less than 15% when estimated over a minimum of 100 broods.     

How do alien plants distribute along roads on oceanic islands? A case study in Tenerife, Canary Islands

Islands are paradigms of the pervasive spread of alien plants, but little work has been done assessing pattern and cause of the distribution of such plants in relation to roads on oceanic islands. We studied richness, composition, and distribution of alien plants and compared them with native species along roads on Tenerife (Canary Islands). We studied a single road transect that sampled two contrasting wind-facing aspects (leeward versus windward) and ran from coastal Euphorbia scrubland through thermophilous scrubland to Makaronesian laurel forest at the top of a mountainous massif. We evaluated the effects of elevation, aspect, distance to urban nuclei, and several road-edge features (including road-edge width and management—implying disturbance intensity), using regression models, analysis of variance, and multivariate ordination methods. Richness of both endemics and native nonendemics was explained by elevation (related to well-defined vegetation belts), steepness of the edge slope, and cover of rocky ground. Despite a short elevational gradient (0–650 m), we found clear altitudinal zonation by biogeographic origin of both nonendemic natives and aliens, and altitudinal distribution of aliens followed the same zonation as that of natives. Alien species’ richness was related to management intensity determining edge disturbance, road-edge width, and distance to the nearest urban nuclei (propagule sources). Different variables explained distribution patterns of natives, endemics, and aliens along roadsides on leeward and windward aspects. Altitude and aspect also had a strong influence on the frequency of life strategies (woody species, annuals and biennial/perennial herbs) of roadside plant communities. Due to harsher environmental filters operating on the leeward aspect, alien species were distributed along the altitudinal gradient in apparent consistency with general biogeographical affinities. Tropical/subtropical taxa showed exponential decrease with increasing elevation, Mediterranean taxa showed a unimodal response (i.e., maximum richness at mid elevation, minimum at the extremes of the gradient), and temperate taxa showed linear increase with elevation. Native but nonendemic species followed analogous trends to those of aliens. This suggests climatic matching as a prerequisite for successful invasion of this topographically complex island. Other road traits, such as edge width, slope steepness, soil cover, and road-edge disturbance intensity may play a complementary role, at a more local scale, to shape the distribution of alien plants on these island roads.     

How do cytokinins affect the cell?

The lecture presents modern knowledge of the mechanisms of cytokinin perception and signal transduction to the genes of primary and secondary responses. It also demonstrates the relations between the rapid cytokinin-induced processes and cytokinin-induced physiological effects. The characteristics of the cytokinin regulatory system and its role in the control of plant growth and development are discussed.     

How do chemical denaturants affect the mechanical folding and unfolding of proteins?

We present the first single-molecule atomic force microscopy study on the effect of chemical denaturants on the mechanical folding/unfolding kinetics of a small protein GB1 (the B1 immunoglobulin-binding domain of protein G from Streptococcus). Upon increasing the concentration of the chemical denaturant guanidinium chloride (GdmCl), we observed a systematic decrease in the mechanical stability of GB1, indicating the softening effect of the chemical denaturant on the mechanical stability of proteins. This mechanical softening effect originates from the reduced free-energy barrier between the folded state and the unfolding transition state, which decreases linearly as a function of the denaturant concentration. Chemical denaturants, however, do not alter the mechanical unfolding pathway or shift the position of the transition state for mechanical unfolding. We also found that the folding rate constant of GB1 is slowed down by GdmCl in mechanical folding experiments. By combining the mechanical folding/unfolding kinetics of GB1 in GdmCl solution, we developed the “mechanical chevron plot” as a general tool to understand how chemical denaturants influence the mechanical folding/unfolding kinetics and free-energy diagram in a quantitative fashion. This study demonstrates great potential in combining chemical denaturation with single-molecule atomic force microscopy techniques to reveal invaluable information on the energy landscape underlying protein folding/unfolding reactions.     

How did environmental disturbances affect carnivoran diversity? A case study of the Plio–Pleistocene Carnivora of the North-Western Mediterranean

The Plio–Pleistocene carnivores from the North-Western Mediterranean (Iberian and Italian peninsulas, and France) are analysed in order to investigate whether their diversity over the last 5.3 Ma was influenced by disturbances of the physical environment. Trends in species diversity over time were analysed in successive unequal time intervals, which were reassessed on the basis of local biochronological schemes. By using a taxon-free characterisation, species were assigned to various ecological categories in accordance with feeding and hunting behaviour, preferred habitat, and average body mass. Principal Component Analysis identified the most important ecological variables in recognising changes among the carnivoran Faunal Complexes that characterised each time interval. The results obtained support the hypothesis that some complex, though not always direct relationships exist between environmental changes and shifts in the diversity of Carnivora (especially for forest dwelling carnivorans). However, progressive changes in carnivoran guilds cannot be interpreted as merely a response to climate changes, because intrinsic biotic control (changes in inter-specific and intra-specific competition) also plays an important role in modifying carnivoran diversity. Therefore, climate change seems to trigger the various factors that contribute to the reconstruction of carnivoran palaeocommunities. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

How do pectin methylesterases and their inhibitors affect the spreading of tobamovirus?

After replication in the cytoplasm, viruses spread from the infected cell into the neighboring cells through plasmodesmata, membranous channels embedded by the cell wall. As obligate parasites, viruses have acquired the ability to utilize host factors that unwillingly cooperate for the viral infection process. For example, the viral movement proteins (MP) interacts with the host pectin methylesterase (PME) and both proteins cooperate to sustain the viral spread. However, how and where PMEs interact with MPs and how the PME/MP complexes favor the viral translocation is not well understood. Recently, we demonstrated that the overexpression of PME inhibitors (PMEIs) in tobacco and Arabidopsis plants limits the movement of Tobacco mosaic virus and Turnip vein clearing virus and reduces plant susceptibility to these viruses. Here we discuss how overexpression of PMEI may reduce tobamovirus spreading.     

Invasion success of alien plants: do habitat affinities in the native distribution range matter?

Aim To assess how habitat affinities in the native distribution range influence the invasion success of 282 central European neophytes (alien plants introduced after ad 1500). Location Czech Republic. Methods Classification trees were used to determine which native habitats donate the most alien species, the correspondence between habitats occupied by species in their native and invaded distribution ranges, and invasion success of species originating from different habitats. Results The species most likely to naturalize in Central Europe are those associated with thermophile woodland fringes in their native range (81%), cultivated areas of gardens and parks (75%) and broad‐leaved deciduous woodlands (72%). The largest proportions of invasive species recruit from those that occur on riverine terraces and eroded slopes, or grow in both deciduous woodland and riverine scrub. When the relative role of habitats in the native range is assessed as a determinant of the probability that a species will become invasive in concert with other factors (the species’ residence time, life history, region of origin), the direct effect of habitat is negligible. However, the effect of native habitats on patterns of invasions observed in central Europe is manifested by large differences in the numbers of species they supply to the invaded region. More than 50 neophytes were recruited from each of the following habitats: dry grasslands, ruderal habitats, deciduous woodland, inland cliffs, rock pavements and outcrops, and tall‐herb fringes and meadows. Main conclusions Casual species recruit from a wider range of habitats in their native range than they occupy in the invaded range; naturalized but not invasive species inhabit a comparable spectrum of habitats in both ranges, and successful invaders occupy a wider range of habitats in the invaded than in the native range. This supports the idea that the invasive phase of the process is associated with changes in biological features that allow for extension of the spectrum of habitats invaded.     

How do trabeculae affect the calculation of structural properties of bone?

One difficulty that arises in an analysis of the cross-sectional properties of bone is whether to include cancellous bone in the analysis. The purpose of this paper is to determine how different amounts of cancellous bone affect the measurement of structural properties of bone cross-sections. Thirty-two tibial and femoral cross-sections were chosen at random from a series of cross-sectioned nonhuman primate bones. Geometrical properties were calculated for the cross-sections, and torsional and bending stress analyses were performed. The results suggest that the effect of including cancellous bone in the analysis is closely related to the amount of bone, where it lies within the cross-section, and the type of analysis performed. Including cancellous bone in calculations of structural properties of bone cross-sections may cause the strength and stiffness of the bone to be exaggerated.     

How do habitat amount and habitat fragmentation drive time-delayed responses of biodiversity to land-use change?

Land-use change is a root cause of the extinction crisis, but links between habitat change and biodiversity loss are not fully understood. While there is evidence that habitat loss is an important extinction driver, the relevance of habitat fragmentation remains debated. Moreover, while time delays of biodiversity responses to habitat transformation are well-documented, time-delayed effects have been ignored in the habitat loss versus fragmentation debate. Here, using a hierarchical Bayesian multi-species occupancy framework, we systematically tested for time-delayed responses of bird and mammal communities to habitat loss and to habitat fragmentation. We focused on the Argentine Chaco, where deforestation has been widespread recently. We used an extensive field dataset on birds and mammals, along with a time series of annual woodland maps from 1985 to 2016 covering recent and historical habitat transformations. Contemporary habitat amount explained bird and mammal occupancy better than past habitat amount. However, occupancy was affected more by the past rather than recent fragmentation, indicating a time-delayed response to fragmentation. Considering past landscape patterns is therefore crucial for understanding current biodiversity patterns. Not accounting for land-use history ignores the possibility of extinction debt and can thus obscure impacts of fragmentation, potentially explaining contrasting findings of habitat loss versus fragmentation studies.     

Food security in 2044: How do we control the fungal threat?

Plant fungal pathogens place considerable strain on agricultural productivity and threaten global food security. In recent decades, advances in crop breeding, farming practice and the agrochemical industry have allowed crop yields to keep pace with food demand. In this opinion article, we speculate on which recent technological advances will allow us to maintain this situation into the future. We take inspiration that it is 25 y since the first plant disease resistance genes were cloned, and imagine if and how agricultural control of pathogens will be achieved by the year 2044. We examine which technologies are best poised to make the jump from lab bench to field application, and propose that future control measures will likely depend on effective integrated disease management.