Life History Traits Of Species Research Articles

A multi‐metric index for assessing two decades of community responses to broad‐scale shoreline enhancement and restoration along the Toronto waterfront

Abstract Biodiversity and habitat loss due to historical and continued urbanization and anthropogenic development require continuous efforts to abate ongoing environmental decline. Restoration and enhancement efforts that aim to address biodiversity and habitat loss, have shown some promise at providing suitable habitat for species in the more urbanized nearshore areas of Lake Ontario. Using 20 years of fish community data from the Toronto waterfront, this study examined ecosystem responses in a spatio‐temporal context across wetland and embayment ecotypes. The goals of this study were to (1) assess how fish communities have changed over time in restored, reference and more and less urbanized nearshore ecosystems and (2) determine if restored and enhanced habitats meet the defined fish community management targets. Fish communities were assessed through a newly developed multi‐metric index based on species life history traits and habitat associations like trophic and thermal guild. Fish communities along the waterfront have transitioned from cool and coldwater pelagic species to a higher proportion of native warmwater species, many of them piscivores, associated with cover and vegetation, that meet community targets. These changes are more pronounced at the largest restoration site ‘Tommy Thompson Park’, where community indices approach natural reference levels. This result indicates the benefits and effectiveness of the decade‐long restoration efforts and subsequent monitoring of responses. Our results underline that large‐scale restoration projects in urbanized settings can be of vital importance for freshwater conservation efforts, as well as application scenarios for multi‐metric community indices, and will play an even larger role when looking at Lake Ontario or the Great Lakes as a whole.

Unclear relationships between mean survival rate and its environmental variance in vertebrates.

Current environmental changes may increase temporal variability of life history traits of species thus affecting their long-term population growth rate and extinction risk. If there is a general relationship between environmental variances (EVs) and mean annual survival rates of species, that relationship could be used as a guideline for analyses of population growth and extinction risk for populations, where data on EVs are missing. For this purpose, we present a comprehensive compilation of 252 EV estimates from 89 species belonging to five vertebrate taxa (birds, mammals, reptiles, amphibians and fish) covering mean annual survival rates from 0.01 to 0.98. Since variances of survival rates are constrained by their means, particularly for low and high mean survival rates, we assessed whether any observed relationship persisted after applying two types of commonly used variance stabilizing transformations: relativized EVs (observed/mathematical maximum) and logit-scaled EVs. With raw EVs at the arithmetic scale, mean-variance relationships of annual survival rates were hump-shaped with small EVs at low and high mean survival rates and higher (and widely variable) EVs at intermediate mean survival rates. When mean annual survival rates were related to relativized EVs the hump-shaped pattern was less distinct than for raw EVs. When transforming EVs to logit scale the relationship between mean annual survival rates and EVs largely disappeared. The within-species juvenile-adult slopes were mainly positive at low (<0.5) and negative at high (>0.5) mean survival rates for raw and relativized variances while these patterns disappeared when EVs were logit transformed. Uncertainties in how to interpret the results of relativized and logit-scaled EVs, and the observed high variation in EV's for similar mean annual survival rates illustrates that extrapolations of observed EVs and tests of life history drivers of survival-EV relationships need to also acknowledge the large variation in these parameters.

Identifying global conservation priorities for terrestrial vertebrates based on multiple dimensions of biodiversity.

The Kunming-Montreal Global Biodiversity Framework of the Convention on Biological Diversity calls for an expansion of the current protected areas (PAs) to cover at least 30% of global land and water areas by 2030 (i.e., the 30×30 target). Efficient spatial planning for PA expansion is an urgent need for global conservation practice. A spatial prioritization framework considering multiple dimensions of biodiversity is critical for improving the efficiency of the spatial planning of PAs, yet it remains a challenge. We developed an index for the identification of priority areas based on functionally rare, evolutionarily distinct, and globally endangered species (FREDGE) and applied it to 21,536 terrestrial vertebrates. We determined species distributions, conservation status (global endangerment), molecular phylogenies (evolutionary distinctiveness), and life-history traits (functional rarity). Madagascar, Central America, and the Andes were of high priority for the conservation of multiple dimensions of terrestrial vertebrate biodiversity. However, 68.8% of grid cells in these priority areas had <17% of their area covered by PAs, and these priority areas were under intense anthropogenic and climate change threats. These results highlight the difficulties of conserving multiple dimensions of biodiversity. Our global analyses of the geographical patterns of multiple dimensions of terrestrial vertebrate biodiversity demonstrate the insufficiency of the conservation of different biodiversity dimensions, and our index, based on multiple dimensions of biodiversity, provides a useful tool for guiding future spatial prioritization of PA expansion to achieve the 30×30 target under serious pressures.

The impacts of host traits on parasite infection of montane birds in southwestern China

Parasitic infections have the potential to impact the hosts’ body condition, elevate physiological responses, and ultimately lead to increased mortality. Host-parasite interactions are tied to the ecological and life-history traits of the hosts. While montane birds are susceptible to avian blood parasites, few studies have simultaneously assessed how inter- and intra-specific traits of hosts influence their probability of parasite infection. In this study, we screened for avian blood parasites across 214 individuals from 51 species at two sites, including a lowland farmland at 700 m and a highland forest at 2,500 m, in the Gaoligong Mountains in southwestern China. Overall blood parasite prevalence was 53.74%, with divergent species-specific prevalence ranging from 6.25% to 66.67%. We also measured traits indicative of body condition and physiological responses of each sampled individual. Using Bayesian phylogenetic logistic models, we assessed whether parasite infection probability is associated with ecological and life history traits of host species. Larger bird species were more likely to be infected than smaller bird species, and omnivore species showed lower susceptibility than those with other diets such as insectivores and herbivores. In contrast, foraging strata, nest type, and participation in mixed-species flocks of host species did not affect infection probability. We then used a reduced sample of eight species with more than five individuals, to assess the associations between intra-specific infection probability and host body condition, represented by fat and muscle reserves, and acute stress responses measured through breath rate. While infected individuals were likely to have more fat reserves than non-infected individuals, we did not find any association between infection probability and muscle reserve and body mass, nor with breath rate. Our results revealed that at the species level, specific traits (body mass and diet) of host species predict infection probability and implied a potential link at the individual level between enhanced body condition and increased resilience to parasite infection.

Importance of life history traits for vulnerability to climate change: implications for macroalgal restoration

Fucalean algae are dominant canopy-forming species that create extensive and highly productive ecosystems in the intertidal and subtidal rocky shores of temperate seas. Regrettably, these marine forests are in decline due to various human drivers, with the Mediterranean Sea one of the most threatened areas. To design appropriate restoration strategies adapted to cope with the unavoidable change in future climate conditions, the response to climate change of the candidate species must be considered. It is important to assess how the specific life history traits of the foundational species may determine environmental requirements, and thus responses to future climate change. This knowledge will allow us to predict the potential winners and losers among the species potentially inhabiting the same areas in a future context of global climate change, providing important information to fine-tune future restoration interventions. The aim of this study was to evaluate the response of two canopy-forming species inhabiting similar upper subtidal zones but with different life history traits to a combination of anomalous high temperatures and increased UV radiation. One of the species (Ericaria crinita) was perennial, slightly exposed rocky shores and dwelling in areas where extreme temperatures can be frequent; while the other (Ericaria mediterranea) a semi-perennial species that dwells in wave-exposed zones, with seawater temperatures buffered by the high hydrodynamism. Our results show that the effects of temperature and radiation are species- (mediated by the species life history traits) and life-stage specific. High temperatures strongly affected the adults of both species, especially E. mediterranea. The germlings in addition to being very susceptible to high temperatures, were also vulnerable to UV radiation, exacerbating the impacts of temperature, especially on E. crinita recruits. Interestingly, vulnerability to climate-driven impacts was determined by the specific life history traits, with i) the species dwelling in open areas the most sensitive to warming and, ii) the perennial species the most vulnerable to UV radiation. Last, we discuss how these species-specific responses to climate-driven impacts may be key in terms of species that could foster the resistance and resilience of marine ecosystems to future climate impacts.

Fish microplastic ingestion may induce tipping points of aquatic ecosystems.

Microplastics can be ingested by a wide range of aquatic animals. Extensive studies have demonstrated that microplastic ingestion-albeit often not lethal-can affect a range of species life-history traits. However, it remains unclear how the sublethal effects of microplastics on individual levels scale up to influence ecosystem-level dynamics through cascading trophic interactions. Here we employ a well-studied, empirically fed three-species trophic chain model, which was parameterized to mimic a common type of aquatic ecosystems to examine how microplastic ingestion by fish on an intermediate trophic level can produce cascading effects on the species at both upper and lower trophic levels. We show that gradually increasing microplastics in the ingested substances of planktivorous fish may cause population structure effects such as skewed size distributions (i.e. reduced average body length vs. increased maximal body size), and induce abrupt declines in fish biomass and reproduction. Our model analysis demonstrates that these abrupt changes correspond to an ecosystem-level tipping point, crossing which difficult-to-reverse ecosystem degradation can happen. Importantly, microplastic pollution may interact with other anthropogenic stressors to reduce safe operating space of aquatic ecosystems. Our work contributes to better understanding complex effects of microplastic pollution and anticipating tipping points of aquatic ecosystems in a changing world. It also calls attention to an emerging threat that novel microplastic contaminants may lead to unexpected and abrupt degradation of aquatic ecosystems, and invites systematic studies on the ecosystem-level consequences of microplastic exposure.

Extinction risk of the world's freshwater mammals.

The continued loss of freshwater habitats poses a significant threat to global biodiversity. We reviewed the extinction risk of 166 freshwater aquatic and semiaquatic mammals-a group rarely documented as a collective. We used the International Union for the Conservation of Nature Red List of Threatened Species categories as of December 2021 to determine extinction risk. Extinction risk was then compared among taxonomic groups, geographic areas, and biological traits. Thirty percent of all freshwater mammals were listed as threatened. Decreasing population trends were common (44.0%), including a greater rate of decline (3.6% in 20years) than for mammals or freshwater species as a whole. Aquatic freshwater mammals were at a greater risk of extinction than semiaquatic freshwater mammals (95% CI -7.20 to -1.11). Twenty-nine species were data deficient or not evaluated. Large species (95% CI 0.01 to 0.03) with large dispersal distances (95% CI 0.03 to 0.15) had a higher risk of extinction than small species with small dispersal distances. The number of threatening processes associated with a species compounded their risk of extinction (95% CI 0.28 to 0.77). Hunting, land clearing for logging and agriculture, pollution, residential development, and habitat modification or destruction from dams and water management posed the greatest threats to these species. The basic life-history traits of many species were poorly known, highlighting the need for more research. Conservation of freshwater mammals requires a host of management actions centered around increased protection of riparian areas and more conscientious water management to aid the recovery of threatened species.

Phylogeny, Ecology, and Gene Families Covariation Shaped the Olfactory Subgenome of Rodents.

Olfactory receptor (OR) genes represent the largest multigenic family in mammalian genomes and encode proteins that bind environmental odorant molecules. The OR repertoire is extremely variable among species and is subject to many gene duplications and losses, which have been linked to ecological adaptations in mammals. Although they have been studied on a broad taxonomic scale (i.e., placental), finer sampling has rarely been explored in order to better capture the mechanisms that drove the evolution of the OR repertoire. Among placental mammals, rodents are well-suited for this task, as they exhibit diverse life history traits, and genomic data are available for most major families and a diverse array of lifestyles. In this study, 53 rodent published genomes were mined for their OR subgenomes. We retrieved more than 85,000 functional and pseudogene OR sequences that were subsequently classified into phylogenetic clusters. Copy number variation among rodents is similar to that of other mammals. Using our OR counts along with comparative phylogenetic approaches, we demonstrated that ecological niches such as diet, period of activity, and a fossorial lifestyle strongly impacted the proportion of OR pseudogenes. Within the OR subgenome, phylogenetic inertia was the main factor explaining the relative variations of the 13 OR gene families. However, a striking exception was a convergent 10-fold expansion of the OR family 14 among the phylogenetically divergent subterranean mole-rat lineages belonging to Bathyergidae and Spalacidae families. This study illustrates how the diversity of the OR repertoire has evolved among rodents, both shaped by selective forces stemming from species life history traits and neutral evolution along the rodent phylogeny.

Broad-Scale Assessment of Methylmercury in Adult Amphibians.

Mercury (Hg) is a toxic contaminant that has been mobilized and distributed worldwide and is a threat to many wildlife species. Amphibians are facing unprecedented global declines due to many threats including contaminants. While the biphasic life history of many amphibians creates a potential nexus for methylmercury (MeHg) exposure in aquatic habitats and subsequent health effects, the broad-scale distribution of MeHg exposure in amphibians remains unknown. We used nonlethal sampling to assess MeHg bioaccumulation in 3,241 juvenile and adult amphibians during 2017-2021. We sampled 26 populations (14 species) across 11 states in the United States, including several imperiled species that could not have been sampled by traditional lethal methods. We examined whether life history traits of species and whether the concentration of total mercury in sediment or dragonflies could be used as indicators of MeHg bioaccumulation in amphibians. Methylmercury contamination was widespread, with a 33-fold difference in concentrations across sites. Variation among years and clustered subsites was less than variation across sites. Life history characteristics such as size, sex, and whether the amphibian was a frog, toad, newt, or other salamander were the factors most strongly associated with bioaccumulation. Total Hg in dragonflies was a reliable indicator of bioaccumulation of MeHg in amphibians (R2 ≥ 0.67), whereas total Hg in sediment was not (R2 ≤ 0.04). Our study, the largest broad-scale assessment of MeHg bioaccumulation in amphibians, highlights methodological advances that allow for nonlethal sampling of rare species and reveals immense variation among species, life histories, and sites. Our findings can help identify sensitive populations and provide environmentally relevant concentrations for future studies to better quantify the potential threats of MeHg to amphibians.

Age and growth of the mountain dragon, Diploderma micangshanense (Squamata: Lacertilia: Agamidae)

Abstract Knowledge of life history is important for understanding population ecology. The genus Diploderma is one of the most diverse genera in the family Agamidae, and no data on the life history traits of Diploderma species have been reported to date. Here, the age and growth of a population of D. micangshanense were revealed using skeletochronology for the first time. Females have greater snout-vent length (SVL) than males, but the mean SVL did not significantly differ between the sexes. Age ranged from one to four years in both sexes, and mean ages were 2.24 ± 0.10 years for males and 2.28 ± 0.12 years for females. No significant sexual differences were detected in either age structure or mean age. Age and body size were significantly positively correlated in both sexes. The growth coefficient k (males: 0.510; females: 0.441) and growth rate (males: 4.33 ± 0.38; females: 4.91 ± 0.39) were similar in both sexes. These results have implications for the population dynamics and management of this species.

Animal population decline and recovery after severe fire: Relating ecological and life history traits with expert estimates of population impacts from the Australian 2019-20 megafires

Catastrophic megafires can increase extinction risks; identifying species priorities for management and policy support is critical for preparing and responding to future fires. However, empirical data on population loss and recovery post-fire, especially megafire, are limited and taxonomically biased. These gaps could be bridged if species' morphological, behavioural, ecological and life history traits indicated their fire responses. Using expert elicitation that estimated population changes following the 2019–20 Australian megafires for 142 terrestrial and aquatic animal species (from every vertebrate class, one invertebrate group), we examined whether expert estimates of fire-related mortality, mortality in the year post-fire, and recovery trajectories over 10 years/three generations post-fire, were related to species traits. Expert estimates for fire-related mortality were lower for species that could potentially flee or shelter from fire, and that associated with fire-prone habitats. Post-fire mortality estimates were linked to diet, diet specialisation, home range size, and susceptibility to introduced herbivores that damage or compete for resources. Longer-term population recovery estimates were linked to diet/habitat specialisation, susceptibility to introduced species; species with slower life histories and shorter subadult dispersal distances also had lower recovery estimates. Across animal groups, experts estimated that recovery was poorest for species with pre-fire population decline and more threatened conservation status. Sustained management is likely needed to recover species with habitat and diet specialisations, slower life histories, pre-existing declines and threatened conservation statuses. This study shows that traits could help inform management priorities before and after future megafires, but further empirical data on animal fire response is essential.

Temperature-Driven Selection of Predatory Mirid Bugs for Improving Aphid Control in Sweet Pepper Crops

Recent studies have suggested that predatory mirid bugs may be an effective alternative for controlling aphids in sweet pepper greenhouses. This study examined the effect of three constant temperatures (18, 24, and 30 °C) on the life history traits of predatory mirid species Nesidiocoris tenuis, Macrolophus pygmaeus, and Dicyphus bolivari, preying on the aphid Myzus persicae nicotianae in sweet pepper plants. As the temperature increased, the survival rate decreased for M. pygmaeus and D. bolivari, while for N. tenuis, it was the opposite, and their survival increased. When considering all the biological traits studied together, the estimated intrinsic rate of increase (rm) decreased as the temperature increased for M. pygmaeus and D. bolivari. In contrast, the rate increased as the temperature increased for N. tenuis. These results suggest that M. pygmaeus and D. bolivari are better adapted to lower temperatures than N. tenuis, which is more adapted to warm temperatures. The implications of these results for improving the biological control of aphids in sweet pepper greenhouses through the use of mirid bugs are discussed in relation to different temperature regimes.

The effect of climate change on avian offspring production: A global meta-analysis

Climate change affects timing of reproduction in many bird species, but few studies have investigated its influence on annual reproductive output. Here, we assess changes in the annual production of young by female breeders in 201 populations of 104 bird species (N = 745,962 clutches) covering all continents between 1970 and 2019. Overall, average offspring production has declined in recent decades, but considerable differences were found among species and populations. A total of 56.7% of populations showed a declining trend in offspring production (significant in 17.4%), whereas 43.3% exhibited an increase (significant in 10.4%). The results show that climatic changes affect offspring production through compounded effects on ecological and life history traits of species. Migratory and larger-bodied species experienced reduced offspring production with increasing temperatures during the chick-rearing period, whereas smaller-bodied, sedentary species tended to produce more offspring. Likewise, multi-brooded species showed increased breeding success with increasing temperatures, whereas rising temperatures were unrelated to reproductive success in single-brooded species. Our study suggests that rapid declines in size of bird populations reported by many studies from different parts of the world are driven only to a small degree by changes in the production of young.

Climatic forcing and individual heterogeneity in a resident mountain bird: legacy data reveal effects on reproductive strategies.

Optimization of clutch size and timing of reproduction have substantial effects on lifetime reproductive success in vertebrates, and both individual quality and environmental variation may impact life history strategies. We tested hypotheses related to maternal investment and timing of reproduction, using 17 years (1978-1994) of individual-based life history data on willow ptarmigan (Lagopus l. lagopus, n = 290 breeding females with n = 319 breeding attempts) in central Norway. We analysed whether climatic variation and individual state variables (age and body mass) affected the number of offspring and timing of reproduction, and individual repeatability in strategies. The results suggest that willow ptarmigan share a common optimal clutch size that is largely independent of measured individual states. While we found no clear direct weather effects on clutch size, higher spring temperatures advanced onset of breeding, and early breeding was followed by an increased number of offspring. Warmer springs were positively related to maternal mass, and mass interacted with clutch size in production of hatchlings. Finally, clutch size and timing of reproduction were highly repeatable within individuals, indicating that individual quality guided trade-offs in reproductive effort. Our results demonstrate how climatic forcing and individual heterogeneity in combination influenced life history traits in a resident montane keystone species.

Some fundamental elements for studying social-ecological co-existence in forest common pool resources.

For millennia, societies have tried to find ways to sustain people's livelihoods by setting rules to equitably and sustainably access, harvest and manage common pools of resources (CPR) that are productive and rich in species. But what are the elements that explain historical successes and failures? Elinor Ostrom suggested that it depends on at least eight axiomatic principles of good governance, whereas empirical results suggest that these principles are not sufficient to describe them, especially when applied to CPRs that possess great social and ecological diversity. The aim of this article is to explore the behavior of a mathematical model of multi-species forest dynamics that respects the foundations of ecology and Ostrom's governance theory, in order to detect possible constraints inherent to the functioning of these complex systems. The model reveals that fundamental structural laws of compatibilities between species life-history traits are indeed constraining the level of co-existence (average and variance) between a diversity of co-vulnerable timber resource users (RU) and of competing tree species. These structural constraints can also lead to unexpected outcomes. For instance in wetter forest commons, opening up the access to as many diverse RUs as there are competing tree species, produces a diversity of independently-controlled disturbances on species, collectively improving the chances of coexistence between species with different life-history traits. Similar benefits are observed on forest carbon and on profits from timber harvesting. However in drier forest commons, the same benefits cannot be observed, as predicted on the basis of the constraining laws. The results show that the successes and failures of certain management strategies can be reasonably explained by simple mechanistic theories from ecology and the social-ecological sciences, which are themselves constrained by fundamental ecological invariants. If corroborated, the results could be used, in conjunction with Ostrom's CPR theory, to understand and solve various human-nature coexistence dilemmas in complex social-ecological systems.

Life history traits for Ophryotrocha craigsmithi (Wiklund, Glover &amp; Dahlgren, 2009), a candidate species in integrated multitrophic aquaculture

Ophryotrocha craigsmithi (Wiklund, Glover &amp;amp; Dahlgren, 2009) has repeatedly been observed in high densities at salmonid fish farms in Norway and has been shown to feed on the organic waste released during fish production. This species has therefore been pointed out as a candidate for the benthic component of integrated multitrophic aquaculture (IMTA). Little is known about the life history traits of Ophryotrocha species found at greater depths in temperate waters. Insight into life traits is of key importance in evaluating the bio-mitigation and harvest potential of (benthic) species within IMTA systems. In this study, we aimed to describe key life history traits for O. craigsmithi, such as growth, reproductive pattern, and offset of reproduction. The main findings are as follows: (I) O. craigsmithi exhibits early sexual maturation and rapid growth, going from 5 to 16 mm in length in 8 weeks; (II) their estimated lifetime is approximately 15 weeks with a generation time of 4 weeks; (III) there are strong indications that they are gonochoric semicontinuous spawners; (IV) the majority of mature eggs ranged from 120 to 150 µm; and (V) the larvae developed into a free-swimming stage after approximately 1 week. To this end, we present a framework for assessing the suitability of deposit-feeding polychaetes as candidate species in IMTA, considering environmental adaptiveness, production potential, as well as carbon and nitrogen mitigation capacity. On the basis of this, O. craigsmithi shows a high suitability as an extractive farmed species in benthic IMTA.

Preliminary insight into the reproductive traits of the flapper skate Dipturus intermedius using in-field ultrasonography and circulating hormone concentrations

Due to global population declines, there is a pressing need for data on the life history traits of many elasmobranch species to support the development of species-specific management plans. A lack of information on the reproductive cycle of the Critically Endangered flapper skate Dipturus intermedius was recently identified as a hindrance to its conservation. To address this data gap, we combined non-lethal ultrasound and hormone analysis to investigate the size at maturity and reproductive cycle of the flapper skate in the Loch Sunart to the Sound of Jura Marine Protected Area off the west coast of Scotland. In-field ultrasound imagery revealed encapsulated eggs in utero and was used to determine the presence and size of ovarian follicles. Combining these images with levels of plasma testosterone, progesterone and oestradiol provided valuable insights into the timing of the reproductive cycle and maturity state of the flapper skate. This preliminary study suggests that male skate start to mature at 165 cm and females at 203 cm total length. Oestradiol appears to be the primary hormone controlling the female reproductive cycle and, along with ultrasound images, indicates that females lay pairs of eggs throughout a winter egg-laying season. Our study further highlights how non-lethal methods can be used to investigate the life history of oviparous elasmobranchs in the field. This information will support the identification of important life history groups and their associated habitats and contribute to the development of management strategies for these species.

A Review of the Ecological and Biogeographic Differences of Amazonian Floodplain Forests

Amazonian floodplain forests along large rivers consist of two distinct floras that are traced to their differentiated sediment- and nutrient-rich (várzea) or sediment- and nutrient-poor (igapó) environments. While tree species in both ecosystems have adapted to seasonal floods that may last up to 270–300 days year−1, ecosystem fertility, hydrogeomorphic disturbance regimes, water shortage and drought, fire, and even specific microclimates are distinct between both ecosystems and largely explain the differences in forest productivity and taxonomic composition and diversity. Here, we review existing knowledge about the influence of these environmental factors on the tree flora of both ecosystems, compare species composition and diversity between central Amazonian várzeas and igapós, and show that both ecosystems track distinct species life-history traits. The ecosystem-level and taxonomic differences also largely explain the biogeographic connections of várzeas and igapós to other Amazonian and extra-Amazonian ecosystems. We highlight the major evolutionary force of large-river wetlands for Amazonian tree diversity and explore the scenarios by which the large number of Amazonian floodplain specialist tree species might even contribute to the gamma diversity of the Amazon by generating new species. Finally, we call attention to the urgent need of an improved conservation of Amazonian várzea and igapó ecosystems and their tree species.

SpORtI: The species originality and rarity index combines phylogenetic and functional originality with rarity metrics to provide a new perspective on species rarity

Methods used to assign rarity among species are fundamental to our ecological understanding and conservation of species that are most vulnerable to extinction or extirpation. Bees (Hymenoptera: Apoidea: Anthophila) are at the forefront of declines in pollinator diversity and a comprehensive understanding of their conservation requirements in any landscape is essential. Rarity is generally defined in terms of numerical abundance and geographical distribution, though aspects of species life history, such as degree of specialization and taxonomic relatedness, are also widely recognized as important. Incomplete information on the life histories of many taxa obliges ecologists to rely on species-level classifications of specialization provided by expert opinion or in published site- or region-specific studies. Descriptions of specialization are therefore rooted in characterization of the habitat and introduce subjectivity into rarity calculations through assumptions of how species perceive and use resources. An alternative approach that may reduce this level of subjectivity is to incorporate important life-history elements into species rarity assessments, which are traits of the organism itself and not its environment. Phylogenetic and functional originality are metrics which have been presented as useful for characterizing the uniqueness of species, and thus for developing a more informed index of species rarity. This study describes our Species Originality and Rarity Index (SpORtI) for bees that includes variables reflecting five rarity and originality metrics for each species: numeric rarity, geographic rarity, phenological rarity, phylogenetic originality, and functional originality. We compared species-specific rarity weights generated with this approach against other indices using a bee dataset collected over three years across the 520,000-km2 land area of the Great Lakes Basin and within the United States and found that rankings using our approach differed significantly from other indices. Our index represents an improvement on previous approaches since it incorporates key information identified by other researchers and avoids potential subjectivity associated with assigning habitat specialization. Importantly, SpORtI has the added advantage to incorporate updated species life-history traits reported in the literature to allow for the most comprehensive and timely rarity index. This new index will aid researchers and practitioners in determining what species to focus conservation efforts on, as well as which management treatments and environmental factors affect our most vulnerable species of bees, or other taxa, so that limited resources can be applied to focal areas of conservation concern more effectively and efficiently.

A sea of fireworms? New insights on ecology and seasonal density of Hermodice carunculata (Pallas, 1766) (Annelida) in the Ionian Sea (SE Italy)

Quantitative studies on population dynamics and life history traits of key species are useful to predict changes in the structure and organization of biological communities. In this context, Hermodice carunculata (Pallas, 1766) is a selective scavenger/carnivore polychaete species (known as a fireworm) that, in recent years, has exhibited a northern expansion along the whole basin, including the Italian coasts, and an increasing abundance in its southern areas. Here we report ecological data and fireworm abundances from two shallow stations of the Salento peninsula in the Ionian Sea (Lecce, Italy), characterized by different hydrodynamic exposure levels and structural communities. The observed densities by visual census in the years 2019–2021 (up to 18 ind./15 m2) document a striking shift compared to the past anecdotal reports of the rare occurrence of fireworms along the studied area. Additionally, their abundance seems to be driven by the substrate coverage; in fact, a higher density of fireworms was observed where the biodiversity is richer. Results from this study will serve as a baseline reference for future investigation of the invasiveness potential of a species that can act as a biological marker of ocean warming.