We investigated the role of N₂-fixation by the colony-forming cyanobacterium, Aphanizomenon spp., for the plankton community and N-budget of the N-limited Baltic Sea during summer by using stable isotope tracers combined with novel secondary ion mass spectrometry, conventional mass spectrometry and nutrient analysis. When incubated with ¹⁵N₂, Aphanizomenon spp. showed a strong ¹⁵N-enrichment implying substantial ¹⁵N₂-fixation. Intriguingly, Aphanizomenon did not assimilate tracers of ¹⁵NH₄⁺ from the surrounding water. These findings are in line with model calculations that confirmed a negligible N-source by diffusion-limited NH₄⁺ fluxes to Aphanizomenon colonies at low bulk concentrations (<250 nm) as compared with N₂-fixation within colonies. No N₂-fixation was detected in autotrophic microorganisms <5 μm, which relied on NH₄⁺ uptake from the surrounding water. Aphanizomenon released about 50% of its newly fixed N₂ as NH₄⁺. However, NH₄⁺ did not accumulate in the water but was transferred to heterotrophic and autotrophic microorganisms as well as to diatoms (Chaetoceros sp.) and copepods with a turnover time of ~5 h. We provide direct quantitative evidence that colony-forming Aphanizomenon releases about half of its recently fixed N₂ as NH₄⁺, which is transferred to the prokaryotic and eukaryotic plankton forming the basis of the food web in the plankton community. Transfer of newly fixed nitrogen to diatoms and copepods furthermore implies a fast export to shallow sediments via fast-sinking fecal pellets and aggregates. Hence, N₂-fixing colony-forming cyanobacteria can have profound impact on ecosystem productivity and biogeochemical processes at shorter time scales (hours to days) than previously thought.

Flight speed is expected to increase with mass and wing loading among flying animals and aircraft for fundamental aerodynamic reasons. Assuming geometrical and dynamical similarity, cruising flight speed is predicted to vary as (body mass)(1/6) and (wing loading)(1/2) among bird species. To test these scaling rules and the general importance of mass and wing loading for bird flight speeds, we used tracking radar to measure flapping flight speeds of individuals or flocks of migrating birds visually identified to species as well as their altitude and winds at the altitudes where the birds were flying. Equivalent airspeeds (airspeeds corrected to sea level air density, Ue) of 138 species, ranging 0.01-10 kg in mass, were analysed in relation to biometry and phylogeny. Scaling exponents in relation to mass and wing loading were significantly smaller than predicted (about 0.12 and 0.32, respectively, with similar results for analyses based on species and independent phylogenetic contrasts). These low scaling exponents may be the result of evolutionary restrictions on bird flight-speed range, counteracting too slow flight speeds among species with low wing loading and too fast speeds among species with high wing loading. This compression of speed range is partly attained through geometric differences, with aspect ratio showing a positive relationship with body mass and wing loading, but additional factors are required to fully explain the small scaling exponent of Ue in relation to wing loading. Furthermore, mass and wing loading accounted for only a limited proportion of the variation in Ue. Phylogeny was a powerful factor, in combination with wing loading, to account for the variation in Ue. These results demonstrate that functional flight adaptations and constraints associated with different evolutionary lineages have an important influence on cruising flapping flight speed that goes beyond the general aerodynamic scaling effects of mass and wing loading.

We explore the distribution of sponges along dissolved silica (dSi) concentration gradients to test whether sponge assemblages are related to dSi and to assess the validity of fossil sponges as a palaeoecological tool for inferring dSi concentrations of the past oceans. We extracted sponge records from the publically available Global Biodiversity Information Facility (GBIF) database and linked these records with ocean physiochemical data to evaluate if there is any correspondence between dSi concentrations of the waters sponges inhabit and their distribution. Over 320,000 records of Porifera were available, of which 62,360 met strict quality control criteria. Our analyses was limited to the taxonomic levels of family, order and class. Because dSi concentration is correlated with depth in the modern ocean, we also explored sponge taxa distributions as a function of depth. We observe that while some sponge taxa appear to have dSi preferences (e.g., class Hexactinellida occurs mostly at high dSi), the overall distribution of sponge orders and families along dSi gradients is not sufficiently differentiated to unambiguously relate dSi concentrations to sponge taxa assemblages. We also observe that sponge taxa tend to be similarly distributed along a depth gradient. In other words, both dSi and/or another variable that depth is a surrogate for, may play a role in controlling sponge spatial distribution and the challenge is to distinguish between the two. We conclude that inferences about palaeo-dSi concentrations drawn from the abundance of sponges in the stratigraphic records must be treated cautiously as these animals are adapted to a great range of dSi conditions and likely other underlying variables that are related to depth. Our analysis provides a quantification of the dSi ranges of common sponge taxa, expands on previous knowledge related to their bathymetry preferences and suggest that sponge taxa assemblages are not related to particular dSi conditions. 

Garden Warblers Sylvia borin were studied during autumn stopover in Crete before

crossing the barrier of theMediterranean Sea and the Sahara Desert. Birds followed

with transmitters show extensive stopover periods, which were longer in first-year

birds, 16 days, compared with adult birds, 14 days. The distribution of body masses

frombirds trapped in fig trees were used to estimate the departure body mass and the

results found indicate that both age categories on average depart with a fuel load close

to 100% of lean body mass. The movement of transmitter birds shows di

fferences between

first-year and adult birds. Adult birds move further away from the release site

and many also left the study area. Several were found settled outside the study area,

up to 17 km away, indicating that they regularly make longer stopover movements. It

is suggested that this might be a result of that they return to a place where they stayed

during an earlier migration. It was shown that stopover site fidelity exists and nine

garden warblers were recaptured in the area during a following autumn. The results

found highlights the importance of stopover areas close to the SaharaDesert.

In spring, long-distance migrants are considered to adopta time-minimizing strategy to promote early arrival atbreeding sites. The phenology of spring migration wasexamined and compared between two insular stopoversites in Greece and Sweden for Icterine Warbler, WoodWarbler, Spotted Flycatcher and Collared Flycatcher. All  of them migrate due north which means that some proportion of birds that pass through Greece are headingto Scandinavia. The Collared Flycatcher had the earliestand the Icterine Warbler the latest arrival time. Thedifferences in median dates between Greece and Swedenwere 3–4 weeks and the passages in Sweden weregenerally more condensed in time. The average overallspeed estimates were very similar and varied between129 and 137 km/d. In most of the species higher speedestimates were associated with years when birds arrivedlate in Greece. After crossing continental Europe birdsarrive at the Swedish study site with significantly higherbody masses compared to when they arrive in Greece andthis might indicate a preparation for arriving at breedinggrounds with some overload.

Land-use changes including agricultural intensification are major drivers of biodiversity loss. As other countries, Switzerland introduced agri-environment schemes (AES) to counteract declining agro-biodiversity. Among numerous bryophytes of the agricultural landscape, arable bryophytes have adapted to recurrent tillage. They are short-lived above-ground, while their diaspores may build up a persistent diaspore bank in the soil. We monitored the field hornwort and the Carolina hornwort, characteristic species of the Central European arable bryophyte flora over a period of almost three decades, and studied effects of Biodiversity Promoting Areas (BPAS), a key element of Swiss AES, on arable bryophyte diversity. Hornwort occurrences strongly declined, and stubble-fields left unprocessed until late autumn, the favourite habitat of arable specialist bryophytes, nearly disappeared from 1991 to 2018. The loss of suitable habitats follows from decreased cereal cultivation and direct post-harvest management. Different BPA-fallows, designed to promote birds, flowering plants, or ecosystem services, harboured arable bryophyte specialists, but their richness decreased with fallow age. Diaspore banks contained arable bryophyte specialists not occurring above-ground and may serve as a reservoir during unsuitable cultivation. Targeted modifications of current AES, aiming to maintain habitats favourable for arable bryophytes, are necessary to safeguard the typical arable bryophytes in the Swiss arable landscape.

Ähnlich wie die Wildkräuter in Äckern sind auch die typischen, hochspezialisieren Ackermoose stark gefährdet und im Rückgang begriffen. Biodiversitätsförderflächen könnten dazu beitragen, ihren Rückgang zu stoppen. Entscheidend für den Erhalt der Ackermoose im Schweizer Kulturland ist jedoch, dass genügend und sorgfältig ausgewählte Getreidestoppelfelder nicht vor Ende Oktober gepflügt oder anderweitig bearbeitet werden. 

Background and aims Plants have evolved an unrivalled diversity of reproductive strategies, including variation in the degree of sexual versus clonal reproduction. This variation has important effects on the dynamics and genetic structure of populations. We examined the association between large-scale variation in reproductive patterns and intraspecific genetic diversity in two moss species where sex is manifested in the dominant haploid generation and sex expression is irregular. We predicted that in regions with more frequent realised sexual reproduction, populations should display less skewed sex ratios, more often express sex, and have higher genetic diversity than in regions with largely clonal reproduction.

Methods We assessed reproductive status and phenotypic sex in the dioicous long-lived Drepanocladus trifarius and D. turgescens, in 248 and 438 samples across two regions in Scandinavia with frequent or rare, respectively, realised sexual reproduction. In subsets of the samples, we analysed genetic diversity using nuclear and plastid sequence information and identified sex with a sex-specific molecular marker in non-reproductive samples.

Key results Contrary to our predictions, sex ratios did not differ between regions, genetic diversity did not differ in D. trifarius and was higher in the region with rare sexual reproduction in D. turgescens. Supporting our predictions, relatively more samples expressed sex in D. trifarius in the region with frequent sexual reproduction. Overall, samples were mostly female. Degree of sex expression and genetic diversity differed between sexes.

Conclusions Sex expression levels, regional sex ratios and genetic diversity were not directly associated with regional frequency of realised sexual reproduction, and relationships and variation patterns differed between species. We conclude that a combination of species-specific life histories such as longevity, overall degree of successful sexual reproduction and recruitment, and historic factors, are important to explain this variation. Our data on haploid-dominated plants significantly complement plant reproductive biology.

Background and Aims. Roughly half of the species of bryophytes have separate sexes (dioecious) and half are hermaphroditic (monoecious). This variation has major consequences for the ecology and evolution of the different species. In some sexually reproducing dioecious bryophytes, sex ratio has been shown to vary with environmental conditions. This study focuses on the dioecious wetland moss Drepanocladus trifarius, which rarely produces sexual branches or sporophytes and lacks apparent secondary sex characteristics, and examines whether genetic sexes exhibit different habitat preferences, i.e. whether sexual niche partitioning occurs.

Methods. A total of 277 shoots of D. trifarius were randomly sampled at 214 locations and 12 environmental factors were quantified at each site. Sex was assigned to the individual shoots collected in the natural environments, regardless of their reproductive status, using a specifically designed molecular marker associated with female sex.

Key Results. Male and female shoots did not differ in shoot biomass, the sexes were randomly distributed with respect to each other, and environmental conditions at male and female sampling locations did not differ. Collectively, this demonstrates a lack of sexual niche segregation. Adult genetic sex ratio was female-biased, with 28 females for every male individual.

Conclusions. The results show that although the sexes of D. trifarius did not differ with regard to annual growth, spatial distribution or habitat requirements, the genetic sex ratio as nevertheless significantly female-biased. This supports the notion that factors other than sex-related differences in reproductive costs and sexual dimorphism can also drive the evolution of biased sex ratios in plants

Patterns of sex expression and sex ratios are key features of the life histories of organisms. Bryophytes are the only haploid-dominant land plants. In contrast with seed plants, more than half of bryophyte species are dioecious, with rare sexual expression and sporophyte formation and a commonly female-biased sex ratio. We asked whether variation in sex expression, sex ratio and sporophyte frequency in ten dioecious pleurocarpous wetland mosses of two different families was best explained by assuming that character states  evolved: (1) in ancestors within the respective families or (2) at the species level as a response to recent habitat conditions. Lasso regression shrinkage identified relationships between family membership and sex ratio and sporophyte frequency, whereas environmental conditions were not correlated with any investigated reproductive trait. Sex ratio and sporophyte frequency were correlated with each other. Our results suggest that ancestry is more important than the current environment in explaining reproductive patterns at and above the species level in the studied wetland mosses, and that mechanisms controlling sex ratio and sporophyte frequency are phylogenetically conserved. Obviously, ancestry should be considered in the study of reproductive character state variation in plants.

We investigated whether the European near-endemic moss Drepanocladus lycopodioides has declined in its core distributionarea in the southern Baltic Sea region and explored potential explanations for this. First, we re-visited sites with documentedrecords from 1854 to 1957 in the Stockholm archipelago and nearby mainland in southern Sweden. Second, we comparedthe numbers and distributions of Swedish occurrences, their habitats, and substrates up to 1950 (289 herbarium records),and from 1951 onwards (347) using different map layers. Third, we explored whether inter-annual variation in reproductiveperformance was related to moisture conditions at five sites on an island in the Stockholm archipelago during nine years. Weestimated moisture conditions based on precipitation data and dry days during the time when fertilization occurs in the yearprior to sporophyte maturation. Drepanocladus lycopodioides has strongly decreased in intensively managed agriculturallandscapes but remains frequent in natural or semi-natural habitats on limestone. Sporophyte development varied betweenyears and depended on the weather condition during the fertilization period. Climate forecasts for the study area predict longerdry spells during late spring to late summer, which coincides with the timing of sexual branch initiation and fertilization inthe species. We expect that sporophyte production will likely decrease in the future, which will affect the species’ abilities tore-colonize spots where it vanishes during years with poor growth conditions.

Die Vorkommen von Hornmoosen in den

Äckern des Mittellandes haben seit den frühen 1990er Jahren stark abgenommen (Abb. 2). Die Feldbewirtschaftung, insbesondere das frühe Pflügen und die Bearbeitung von Stoppelfeldern im Herbst, erklären wesentlich die Abnahme der Hornmoose. Damit verschwinden die bevorzugten Standorte für Hornmoose und andere Ackermoos-Spezialisten. Die Einführung des ÖLN, unter anderem wegen der Bodenschutzauflage, die seit 2015 eine Einsaat zeitig nach der Ernte verlangt, hatte also keinen positiven Einfluss auf die Hornmoosvorkommen. Eine hohe Luftfeuchtigkeit im Sommer fördert andererseits die Hornmoosentwicklung, aber dieser Witterungseffekt ist deutlich geringer als der Bewirtschaftungseffekt.

Ähnlich wie die Wildkräuter in Äckern sind auch die typischen, hoch-spezialisieren Ackermoose gefährdet und im Rückgang begriffen. Im Schweizer Mittelland sind ihre bevorzugten Lebensräume, bis in den Spätherbst unbearbeitete Getreidestoppelfelder, fast vollständig verschwunden. Biodiversitätsförderflächen (BFF) können dazu beitragen, ihren Rückgang zu stoppen, allerdings nur so lange nicht die dichte Vegetationsbedeckung und Streuauflagen in den älteren BFF die Ackermoose verdrängen. Entscheidend für den Erhalt der Ackermoose im Schweizer Kulturland ist deshalb die Förderung von kurzlebigen BFF und vor allem von Getreidestoppelfeldern, in denen die Bearbeitungszeitpunkte sorgfältig angepasst sind.

We asked how arable management and the introduction of AES-measures affect the specialised bryophyte flora of arable land, whether these specialist species do occur in existing BPAs, and how weather conditions affect the development of arable bryophyte populations. 

We  propose tailored amendments of certain directives of the Swiss Agri-environmental Schemes (AES) to safeguard the characteristic arable specialist bryophytes in the Swiss arable landscape. 

Agricultural intensification represents one of the major drivers for the dramatic loss of biodiversity worldwide. To halt the decline of farmland biodiversity, Switzerland adopted agri-environment schemes (AES) in 1998. Here, we monitored the occurrence, abundance and habitats of two species of arable bryophyte specialists, the Field hornwort (Anthoceros agrestis) and the Carolina hornwort (Phaeoceros carolinianus), in 28 crop fields in the intensively cultivated Swiss Plateau from 1991–2018, to investigate the effects of arable management, AES directives, and weather conditions on their performance. The target species are characteristic of the specialized short-lived arable bryophyte flora of Central Europe that depend on bare substrate in low-intensively cultivated and regularly ploughed fields. Trends in their occurrence thus reflect in many respects the status of the arable bryophytes in cultivated fields. Hornwort occurrence significantly declined between 1991 and 2018. A strong decrease in stubble fields that remain unmanaged after harvest, the favourite habitat for many arable specialists in the study area, largely accounted for the decline. Stubble fields nearly disappeared in the study area because of a gradual reduction in the cultivation area of cereals and the increasing practice of immediate post-harvest tillage. The latter is common in intensive arable farming and was accentuated by AES directives amended in 2005. Hornwort occurrences were positively affected by high air humidity during summer, but weather effects were subordinate to management effects. We propose tailored amendments of AES regulations, that aremented at selected sites, to maintain the characteristic arable specialist bryophytes in the Swiss Plateau: crop rotation with adequate proportions of cereals that are regularly ploughed but not before the end of October, no post-harvest processing of stubble fields, and optimization of the existing instrument ‘Biodiversity Promoting Areas’, e.g., short-term fallows in crop fields. Late-autumn or overwintering stubbles and short-term fallows will benefit many other organisms that depend on extensively managed open habitats, for example arableflowers, farmland breeding birds and specialized arthropods

Implications of long-term monitoring of arable bryophytes for the conservation of these species in Switzerland

Ponds are important elements of green areas in cities that help counteract the negative consequences of urbanization, by providing important habitats for biodiversity in cities and being essential nodes in the overall landscape-scale habitat network. However, there is relatively little knowledge about the impacts of pond management intensity, function and environmental variables on urban pond biodiversity. In this study we addressed this gap by investigating which factors were correlated with the level of biodiversity in urban ponds, indicated by species richness of aquatic insects, in Stockholm, Sweden. Our study did not confirm any direct link between the perceived intensity of management or function of ponds and overall biodiversity. However, it seems that management can influence particular groups of species indirectly, since we found that Trichoptera richness (Caddisflies) was highest at intermediate management intensity. We suggest that this is caused by management of vegetation, as the amount of floating and emergent vegetation was significantly correlated with both the overall species richness and the richness of Trichoptera (Caddisflies). This relationship was non-linear, since ponds with an intermediate coverage of vegetation had the highest richness. Interestingly, the amount of vegetation in the pond was significantly affected by pond function and pond management. The overall species richness and richness of Trichoptera were also positively correlated with pond size. Since we found that the pattern of relations between species richness and environmental variables differed between the insect groups we suggest that it will be difficult to provide overall design and management recommendations for ponds in urban green areas. Therefore, it is recommended that to provide high aquatic diversity of species in urban areas one should aim at promoting high diversity of different types of ponds with differing management and environmental factors that shape them.

Urban small water bodies, such as ponds, are essential elements of human socio-economic landscapes. Ponds also provide important habitats for species that would otherwise not survive in the urban environment. Knowledge on the biodiversity of urban ponds and the relationship between their ecological value and factors linked to urbanization and socio-economic status is crucial for decisions on where and how to establish and manage ponds in cities to deliver maximum biodiversity benefits. Our study investigates if the pattern of urban-pond biodiversity can be related to different socio-economic factors, such as level of wealth, education or percentage of buildings of different types. Because of lack of previous studies investigating that, our study is of exploratory character and many different variables are used.We found that the biodiversity of aquatic insects was significantly negatively associated with urbanisation variables such as amount of buildings and number of residents living around ponds. This relationship did not differ depending on the spatial scale of our investigation. In contrast, we did not find a significant relationship with variables representing socio-economic status, such as education level and wealth of people. This latter result suggests that the socio-economic status of residents does not lead to any particular effect in terms of the management and function of ponds that would affect biodiversity. However, there is a need for a finer-scale investigation of the different potential mechanism in which residents in areas with differing socio-economic status could indirectly influence ponds.

Animals and microorganisms often establish close ecological relationships. However, much of our knowledge about animal microbiomes comes from two deeply studied groups: vertebrates and arthropods. To understand interactions on a broader scale of diversity, we characterized the bacterial microbiomes of close to 1,000 microscopic marine invertebrates from 21 phyla, spanning most of the remaining tree of metazoans. Samples were collected from five temperate and tropical locations covering three marine habitats (sediment, water column and intertidal macroalgae) and bacterial microbiomes were characterized using 16S ribosomal RNA gene sequencing. Our data show that, despite their size, these animals harbour bacterial communities that differ from those in the surrounding environment. Distantly related but coexisting invertebrates tend to share many of the same bacteria, suggesting that guilds of microorganisms preferentially associated with animals, but not tied to any specific host lineage, are the main drivers of the ecological relationship. Host identity is a minor factor shaping these microbiomes, which do not show the same correlation with host phylogeny, or ‘phylosymbiosis’, observed in many large animals. Hence, the current debate on the varying strength of phylosymbiosis within selected lineages should be reframed to account for the possibility that such a pattern might be the exception rather than the rule.

Ocean deoxygenation driven by global warming and eutrophication is a primary concern for marine life. Resistant animals may be present in dead zone sediments, however there is lack of information on their diversity and metabolism. Here we combined geochemistry, microscopy, and RNA-seq for estimating taxonomy and functionality of micrometazoans along an oxygen gradient in the largest dead zone in the world. Nematodes are metabolically active at oxygen concentrations below 1.8μmolL−1, and their diversity and community structure are different between low oxygen areas. This is likely due to toxic hydrogen sulfide and its potential to be oxidized by oxygen or nitrate. Zooplankton resting stages dominate the metazoan community, and these populations possibly use cytochrome c oxidase as an oxygen sensor to exit dormancy. Our study sheds light on mechanisms of animal adaptation to extreme environments. These biological resources can be essential for recolonization of dead zones when oxygen conditions improve.

Introduction: Codonoblepharon forsteri is a rare epiphytic moss characteristically associated with water-filled holes in trees. This study aims to review its range and population and assess effects of climate change.

Methods: An inventory of sites from where C. forsteri has been recorded was compiled. Extent of Occurrence (EOO) and Area of Occupancy (AOO) were calculated. Population size was estimated, using an occupied tree as an ‘individual-equivalent’ of the moss. Climatic conditions of its current distribution were characterised, and an ensemble model of its distribution generated. The latter was projected onto present and future climatic layers.

Results: C. forsteri has been recorded from 205 sites in 18 countries, in Europe, N Africa and SW Asia. It has been undergoing an overall decline. Most sites have few occupied trees, and a world population of 1000–10,000 individual-equivalents is estimated. Model projections suggest the species will experience a range increase of +0.27–0.78 by 2050 and +0.34–0.97 by 2070, especially in the NW, in particular across France and the UK. Range loss is predicted to be -0.16–0.23 in 2050 and -0.18–0.32 in 2070, affecting the driest areas of the current range around the Mediterranean, especially in N Africa.

Conclusions: C. forsteri has a relatively large EOO but a relatively small AOO, likely the product of its habitat specialism. A major reason for recent declines appears to be widespread abandonment of traditional ‘pollarding’ of trees. The potential climatic range of the species will shift significantly northwards over the next few decades

Increasing food production while avoiding negative impacts on biodiversity constitutes one of the main challenges of our time. Traditional silvopastoral systems like Iberian oak savannas (“dehesas”) set an example, where free-range livestock has been reared for centuries while preserving a high natural value. Nevertheless, factors decreasing productivity need to be addressed, one being acorn losses provoked by pest insects. An increased and focalized grazing by livestock on infested acorns would kill the larvae inside and decrease pest numbers, but increased livestock densities could have undesired side effects on ground arthropod communities as a whole. We designed an experimental setup including areas under trees with livestock exclosures of different ages (short-term: 1-year exclusion, long-term: 10-year exclusion), along with controls (continuous grazing), using DNA metabarcoding (mitochondrial markers COI and 16S) to rapidly assess arthropod communities’ composition. Livestock removal quickly increased grass cover and arthropod taxonomic richness and diversity, which was already higher in short-term (1-year exclosures) than beneath the canopies of control trees. Interestingly, arthropod diversity was not highest at long-term exclosures (≥10 years), although their community composition was the most distinct. Also, regardless of treatment, we found that functional diversity strongly correlated with the vegetation structure, being higher at trees beneath which there was higher grass cover and taller herbs. Overall, the taxonomic diversity peak at short term exclosures would support the intermediate disturbance hypothesis, which relates it with the higher microhabitat heterogeneity at moderately disturbed areas. Thus, we propose a rotatory livestock management in dehesas: plots with increased grazing should co-exist with temporal short-term exclosures. Ideally, a few long-term excluded areas should be also kept for the singularity of their arthropod communities. This strategy would make possible the combination of biological pest control and arthropod conservation in Iberian dehesas.

Long-term monitoring of species is necessary for estimating trends in abundance and distribution, andassessing impacts of human activities and conservation actions. As the monitoring needs often exceedavailable resources, optimisation of monitoring effort is important. As part of the Swedish nationalmonitoring programme of harbour porpoises, echolocation activity has been measured at 14 stationslocated in five Natura 2000 sites in the Kattegat Sea over four years (2019–2023). We aimed to evaluatewhether monitoring effort could be reduced while still providing the power to detect a 30% decline overthree generations (equivalent to an annual decline of 1.6%) with 80% power and 20% significance, i.e.similar to OSPAR’s threshold for abundance of cetacean assessment units. Stations were divided intofour groups (3–5 stations/group) based on their spatial distribution and the level and variation in the ratioof the weekly buzz-positive minutes (BPM) to detection-positive minutes (DPM). The BPM metrics wereassumed to indicate differences in habitat use. For each station, daily DPM was modelled as a functionof the Julian day and year to create annual indices. For each group, the trend of the annual indices andassociated power was calculated using a log-linear model over the four years. Finally, the power todetect a trend over time using 1–3 stations per group was estimated, assuming three levels of variance.The variance levels chosen were similar to the lowest, mean and highest variance observed for the 14stations over the four monitoring years. For all four groups of stations, a significant trend was estimatedto be detected within 12 years. The power analysis showed that decreasing the number of stations withina group from 3 to 2 delays the time to reach 80% power by approximately 1 year, while decreasing it from2 to 1 delays it by approximately 2 years. Alternating stations within a group has negligible impact on thepower. Depending on the assumed level of variance, a significant trend could be detected using 2 stationsper group within 6 (σ=0.05), 12 (σ=0.15), or 18 years (σ=0.30). The results indicate that monitoring effortcan be moved to other areas, while still providing sufficient power to allow declines in detections to bedetected within 12 years. Further, they demonstrate that clear objectives and evaluation of the effortneeded are crucial for optimisation among areas, populations or species when resources are limited.

Predation is an ecologically important process, and intra-guild interactions may substantially influence the ecological effects of predator species. Despite a rapid expansion in the use of mathematical graph theory to describe trophic relations, network approaches have rarely been used to study interactions within predator assemblages. Assemblages of diurnal raptors are subject to substantial intra- and interspecific competition. Here we used the novel approach of applying analyzes based on network topology to species-specific data on the stable isotopes 13C and 15N in feathers to evaluate patterns of relative resource utilization within a guild of diurnal raptors in northern Sweden. Our guild consisted of the golden eagle (Aquila chrysaetos), the gyrfalcon (Falco rusticolus), the peregrine falcon (Falco peregrinus) and the rough-legged buzzard (Buteo lagopus). We found a modular trophic interaction structure within the guild, but the interactions were less nested than expected by chance. These results suggest low redundancy and hence a strong ecological importance of individual species. Our data also suggested that species were less connected through intra-guild interactions than expected by chance. We interpret our results as a convergence on specific isotope niches, and that body size and different hunting behaviour may mediate competition within these niches. We finally highlight that generalist predators could be ecologically important by linking specialist predator species with disparate dietary niches.

Intense competition with lianas (woodclimbers) can limit tree growth, reproduction, andsurvival. However, the negative effects of liana loadson tree allometry have not yet been addressed. Weinvestigated the hypothesis that liana loading on treecrown alters tree’s allometry, expressed throughslenderness (height–diameter ratio). The relationshipbetween trunk slenderness and percentage of treecrown covered by lianas was investigated for 12 treespecies from 10 fragments of the SemideciduousSeasonal Forest in Southeastern Brazil. We also testedwhether the relationship between slenderness andwood density differ between trees without lianas andtrees heavily infested. Liana loads significantly alteredtree allometry by decreasing slenderness, even whenlianas covered less than 25% of tree crown. Heavywoodspecies decreased their trunk slenderness in agreater ratio than light-wood species. Our findingsindicate that liana infestation shifts tree allometry, andthese effects are stronger on heavy-wood tree species.

QuestionWe aimed to analyze how the topography, temperature and rainfall influence the floristic distribution in three different topographic areas and their surrounding vegetation. We addressed three main questions: (i) How is the distribution of species among the topographic areas? (ii) Which abiotic variable is driving this distribution? and (iii) What is the difference among the mountain forests and between mountain forests and the Caatinga vegetation?LocationThe Maranguape mountain forest were divided into three topographic categories: windward (600–800 m, WMA), leeward (600–800 m, LMA) and top (above 800 m, TMA). We also considered another six areas of mountain forests and four Caatinga areas in Ceará State.MethodsWe calculated different structural parameters and the floristic diversity of each category. A Principal Correspondence Analysis was performed to analyze the indirect ordination of forest sites by species abundance. A Canonical Correspondence Analysis was conducted to evaluate which variables were driving species distribution. We used non‐metric multidimensional scaling distance and the average linkage method to investigate the similarity among mountain forests and Caatinga.ResultsA total of 1,536 individuals belonging to 144 tree species distributed in 44 families and 93 genera were recorded. Myrtaceae, Fabaceae and Rubiaceae were the most species‐rich families. Myrcia splendens had the highest importance value followed by Guapira nitida and Mollinedia ovata. The leeward slope showed the highest richness and diversity index, whereas the windward showed the highest density and the top showed the highest basal area. The ordination indicated a greater similarity between TMA and WMA than LMA.ConclusionOur results suggest that temperature, precipitation and slope angle are the abiotic factors driving species distribution in Maranguape. Those mountains are heavily anthropized and continuously explored, therefore these outcomes will be useful for conservation and restoration purposes in the poorly known semiarid region of Northeast Brazil.

Background and AimsWe examined the relationship between reproductive allocation and vegetative growth in three monoicous sexual systems of bryophytes. The sexual systems show a gradient of increasing distance between the sexes, from gonioautoicous to cladautoicous to rhizautoicous. Here, we investigated the following two hypotheses: (1) reproductive allocation differs between sexes and sexual systems, and male reproductive allocation increases with increasing distance between male and female gametangia; and (2) reproductive allocation is negatively related to vegetative growth.MethodsWe sampled the three sexual systems, represented by three moss species of the genus Fissidens in the Atlantic Forest of Southeastern Brazil. Ramets were washed in the laboratory; the reproductive structures were detached from the vegetative ramets and sorted regarding sex and individual, dried at 70 °C for 72 h, and weighed in an ultramicrobalance. We calculated the mean reproductive and vegetative mass and reproductive allocation and used generalized linear models to test our predictions.Key ResultsReproductive allocation differed between species and sexes. It was higher in the rhizautoicous than in the cladautoicous and gonioautoicous species. Mean reproductive allocation was greater in males than in females of the rhizautoicous species, greater in females than males of the cladautoicous species, and did not differ between the sexes in the gonioautoicous species. Estimates of reproductive and vegetative mass were positively related in females of the rhizautoicous species. Vegetative mass was not related to reproductive allocation in the gonioautoicous species, but negatively related to reproductive allocation in the male and female branchlets of the cladautoicous species and in the female ramets of the rhizautoicous species.ConclusionsThe reproductive allocation patterns differ between the rhizautoicous species and the ‘truly’ monoicous species, with shorter intersexual distances, which implies that our hypotheses were supported only in part. We suggest that the hypotheses should be reformulated and tested further by comparing ‘truly’ monoicous species with dioicous species and by including other genera.