Life-history Attributes Research Articles

From facultative to obligatory parental care: Interspecific variation in offspring dependency on post-hatching care in burying beetles.

Studies on the evolution of parental care have focused primarily on the costs and benefits of parental care and the life-history attributes that favour it. However, once care evolves, offspring in some taxa appear to become increasingly dependent on their parents. Although offspring dependency is a central theme in family life, the evolutionary dynamics leading to it are not fully understood. Beetles of the genus Nicrophorus are well known for their elaborate biparental care, including provisioning of their young. By manipulating the occurrence of pre- or post-hatching care, we show that the offspring of three burying beetle species, N. orbicollis, N. pustulatus, and N. vespilloides, show striking variation in their reliance on parental care. Our results demonstrate that this variation within one genus arises through a differential dependency of larvae on parental feeding, but not on pre-hatching care. In N. pustulatus, larvae appear to be nutritionally independent of their parents, but in N. orbicollis, larvae do not survive in the absence of parental feeding. We consider evolutionary scenarios by which nutritional dependency may have evolved, highlighting the role of brood size regulation via infanticide in this genus.

Long-term bird colonization and turnover in restored woodlands

The long-term effectiveness of restored areas for biodiversity is poorly known for the majority of restored ecosystems worldwide. We quantified temporal changes in bird occurrence in restoration plantings of different ages and geometries, and compared observed patterns with a reference dataset from woodland remnants on the same farms as our plantings. Over time, bird species richness remained unchanged in spring but exhibited modest increases in winter. We found that wider plantings supported significantly greater bird species richness in spring and winter than narrow plantings. There was no evidence of a significant interaction between planting width and time. We recorded major temporal changes in the occurrence of a range of individual species that indicated a clear turnover of species as plantings matured. Our results further revealed marked differences in individual species occurrence between plantings and woodland remnants. Life-history attributes associated with temporal changes in the bird assemblage were most apparent in winter survey data, and included diet, foraging and nesting patterns, movement behaviour (e.g. migratory vs. dispersive), and body size. Differences in bird assemblages between plantings of different ages suggest that it is important that farms support a range of age classes of planted woodland, if the aim is to maximize the number of native bird species in restored areas. Our data also suggest that changes in the bird species occupying plantings of different ages can be anticipated in a broadly predictable way based on planting geometry (especially width) and key life-history attributes, particularly movement patterns and habitat and diet specialisation.

Contrasting responses of small mammals to fire and topographic refugia

AbstractUnburnt patches within burnt landscapes are expected to provide an important resource for fauna, potentially acting as a refuge from direct effects of fire and allowing animals to persist in burnt landscapes. Nevertheless, there is little information about the way refugia are used by fauna and how populations may be affected by them. Planned burns are often patchy, with unburnt areas generally associated with gully systems providing a good opportunity to study faunal use of refugia. We used a before–after control‐impact design associated with a planned burn in south eastern Australia to investigate how two small mammal species, the bush rat Rattus fuscipes and agile antechinus Antechinus agilis, used unburnt gully systems within a larger burnt area. We tested three alternative hypotheses relating to post‐fire abundance: (i) active refugia – abundance would increase in unburnt patches because of a post‐fire shift of individuals from burnt to unburnt areas; (ii) passive refugia – abundance in unburnt patches would remain similar to pre‐fire levels; and (iii) limited or no refugia – abundance would reduce in unburnt patches related to the change induced by fire in the wider landscape. We found the two species responded differently to the presence of unburnt refugia in the landscape. Relative to controls, fire had little effect on bush rat abundance in gullies, supporting hypothesis 2. In contrast, agile antechinus abundance increased in gullies immediately post‐fire consistent with a shift of individuals from burnt parts of the landscape, supporting hypothesis 1. Differences in site fidelity, habitat use and intraspecific competition between these species are suggested as likely factors influencing responses to refugia. The way unburnt patches function as faunal refugia and the subsequent influence they have on post‐fire population dynamics, will to some extent depend on the life history attributes of individual species.

Effects of declining calcium availability on the survival, growth and calcium content of a freshwater crayfish, Orconectes virilis

Summary Calcium (Ca) decline is a severe and widespread phenomenon threatening softwater ecosystems around the world. In north temperate lakes, these declines have been linked with declines in numerous freshwater taxa, in particular, crustacean zooplankton and crayfish. The purpose of this study was to determine, under lab conditions, the effect of low Ca concentrations on survival, growth and Ca content of a freshwater crayfish, Orconectes virilis, originating in a region experiencing Ca decline. We found that survival of juvenile O. virilis was significantly reduced at 0.5–0.9 mg L−1, which is among the lowest requirement reported for a freshwater crayfish. Neither growth nor whole‐body Ca content were related to Ca concentration. Based on these findings, the acute tolerance of O. virilis to low Ca may allow the species to persist under forecast concentrations of lakes in regions experiencing Ca decline; however, most lakes are experiencing stress from multiple environmental agents which could influence the impact of Ca on mortality and potentially other life history attributes.

Population genetic analysis of a medicinally significant Australian rainforest tree, Fontainea picrosperma C.T. White (Euphorbiaceae): biogeographic patterns and implications for species domestication and plantation establishment.

BackgroundFontainea picrosperma, a subcanopy tree endemic to the rainforests of northeastern Australia, is of medicinal significance following the discovery of the novel anti-cancer natural product, EBC-46. Laboratory synthesis of EBC-46 is unlikely to be commercially feasible and consequently production of the molecule is via isolation from F. picrosperma grown in plantations.Successful domestication and plantation production requires an intimate knowledge of a taxon’s life-history attributes and genetic architecture, not only to ensure the maximum capture of genetic diversity from wild source populations, but also to minimise the risk of a detrimental loss in genetic diversity via founder effects during subsequent breeding programs designed to enhance commercially significant agronomic traits.ResultsHere we report the use of eleven microsatellite loci (PIC = 0.429; PID = 1.72 × 10−6) to investigate the partitioning of genetic diversity within and among seven natural populations of F. picrosperma. Genetic variation among individuals and within populations was found to be relatively low (A = 2.831; HE = 0.407), although there was marked differentiation among populations (PhiPT = 0.248). Bayesian, UPGMA and principal coordinates analyses detected three main genotypic clusters (K = 3), which were present at all seven populations. Despite low levels of historical gene flow (Nm = 1.382), inbreeding was negligible (F = -0.003); presumably due to the taxon’s dioecious breeding system.ConclusionThe data suggests that F. picrosperma was previously more continuously distributed, but that rainforest contraction and expansion in response to glacial-interglacial cycles, together with significant anthropogenic effects have resulted in significant fragmentation. This research provides important tools to support plantation establishment, selection and genetic improvement of this medicinally significant Australian rainforest species.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-016-0743-2) contains supplementary material, which is available to authorized users.

Life history variation among four lake trout morphs at Isle Royale, Lake Superior

Abstract Life history traits were compared among four morphs of lake trout at Isle Royale, Lake Superior. Of 738 lake trout caught at Isle Royale, 701 were assigned to a morph (119 humpers, 160 leans, 85 redfins, and 337 siscowets) using a combination of statistical analysis of head and body shape and visual assignment. On average, redfins were longer (544 mm), heavier (1481 g), heavier at length, more buoyant, and older (22 years) than siscowets (519 mm; 1221 g; 19 years), leans (479 mm; 854 g; 13 years), and humpers (443 mm; 697 g; 17 years). On average, leans grew from a younger age at length = 0 and shorter length at age = 0, at a faster early growth rate to a longer asymptotic length than the other three morphs, while redfins grew at a slower instantaneous rate and humpers grew to a shorter asymptotic length than other morphs. On average, leans were longer (562 mm) and older (15 years) at 50% maturity than redfins (427 mm, 12 years), siscowets (401 mm, 11 years), or humpers (394 mm, 13 years). Life history parameters did not differ between males and females within each morph. We conclude that differences in life history attributes of lean, humper, redfin, and siscowet morphs of lake trout are consistent with differential habitat use in waters around Isle Royale, Lake Superior.

Mesohabitat associations in the Mississippi River Basin: a long-term study on the catch rates and physical habitat associations of juvenile silver carp and two native planktivores

Fish community structure is a complex and integrated part of an aquatic ecosystem; a balanced system is often rich in species diversity and abundance. Invasive species can alter this balance, and the expansion of invasive silver carp may have similar deleterious effects. Recently, catches of silver carp in the Midwestern United States have increased and there is evidence of successful spawning and recruitment. However, early life history attributes of silver carp have not been fully evaluated within the Mississippi River Basin. A thorough understanding of early-life history is imperative to facilitate control efforts for silver carp populations. Furthermore, age-0 silver carp survival and subsequent recruitment may be regulated by habitat availability during this critical life stage. Thus, the objective of this study was to evaluate age-0 silver carp mesohabitat (i.e., depth, velocity, and substrate) use in three reaches of the Mississippi River Basin and potential habitat overlap with two native planktivorous fish species, gizzard shad Dorosoma cepedianum and emerald shiner Notropis atherinoides. Using data collected from the three lower most reaches of the Long Term Resource Monitoring Program (Pool 26 at Alton, Illinois, USA; Open River at Cape Girardeau, Missouri, USA of the Mississippi River; and the LaGrange reach at Havana, Illinois, USA of the Illinois River), we investigated age-0 silver carp, age-0 gizzard shad and age-0 emerald shiner habitat associations from 2007 to 2012. Overall, 79,358 age-0 silver carp, 89,990 gizzard shad and 41,119 emerald shiner were captured with mini fyke nets during this long-term study. Generally, all three species were collected most frequently in shallow (< 1.5 meters), low velocity (<0.6 meters/second) habitat with greater variability in substrate use ranging from silt to rock. Given the scarcity of these habitat types in the channelized Mississippi River Basin, our results suggest that invasive silver carp exhibit habitat overlap with gizzard shad and emerald shiner. This overlap may result in reduced growth and body condition of these fishes. To this end, this extensive data set has provided new information about silver carp early life history mesohabitat use and overlap occurring between two age-0 native planktivores in the Mississippi River Basin and potential consequences of this association.

Responses of adult Hydrellia lagarosiphon to a revised diet: implications for life cycle studies and laboratory culturing techniques

AbstractPreservation of an insect culture under laboratory conditions is essential for its study. Numerous diets have been developed for entomophagous insects undergoing screening as biological control agents in attempts to improve the nutritional quality of food provided in laboratory settings. However, less emphasis has been given to developing a more effective laboratory diet for phytophagous insects with the adult life stage not dependant on the target species. The larvae of Hydrellia lagarosiphon Deeming (Diptera: Ephydridae) mine the leaves of Lagarosiphon major (Ridl.) Moss ex Wager (Hydrocharitaceae). This species is currently under consideration as a biological control agent of this aquatic invasive. Rearing techniques for the adult stage of other Hydrellia species have been developed but current diets are not ideal as they result in relatively low reproduction rates. We compared alternative nutritional regimes and quantified their impact on life history attributes of H. lagarosiphon. The diets included the previously developed yeast‐sugar diet, a newly developed insect‐derived diet, and a diet that combined the two. Total fecundity was significantly higher for females on an insect‐derived diet compared with the traditional carbohydrate diet and the net reproductive rate (Ro) was also higher. Population doubling time (Td) was lower, decreasing by 30% compared to the traditional laboratory diet developed for Hydrellia species. Adult females fed the combination diet, including both insect and non‐insect foods, laid 30% fewer eggs than those reared on an insect diet alone. Consequently, insect‐derived nutritional regimes could improve culturing techniques significantly and if permission to release the agent is granted, this diet may benefit mass rearing efforts potentially saving time and reducing associated costs.

Sensitivity of breeding birds to the “human footprint” in western Great Lakes forest landscapes

Breeding birds in forest ecosystems are generally diverse, habitat selective, and easily sampled. Because they must integrate environmental variables over space and time, local populations of forest birds (like other animal and plant taxa) may provide meaningful signals of local forest health or degradation. We evaluated 949 breeding bird surveys in areas ranging from degraded urban/suburban forest remnants to relatively pristine old growth forests in the western Laurentian Great Lakes region of North America. The “human footprint” across this landscape was represented by a one‐dimensional numeric gradient derived from land cover variables, forest fragmentation metrics, and publicly available data on housing density and transportation corridors. We used an iterative, maximum likelihood approach to quantify species‐specific responses to this human disturbance gradient. Many species showed significant directional responses, consistent with known life history attributes. Other species were most commonly detected at intermediate levels of anthropogenic disturbance, yielding unimodal responses. Relationships between the “human footprint” and occurrences of 38 bird species were illustrated by general Gaussian functions that represented both unidirectional and unimodal patterns. These biotic response (BR) functions were combined into a bird‐based index of ecological condition (IEC) ranging from 0 (maximally degraded) to 10 (minimally degraded). We described a successful application of the IEC method at the Wild Rivers Legacy Forest (WRLF), a &gt;260 km2 conservation landscape in northeastern Wisconsin, USA, managed primarily under a working forest conservation easement established in 2006. In general, areas within the WRLF yielded high IEC values (7.0–9.0), but nearby forest areas not under the conservation easement were characterized by significantly lower IEC values based on breeding bird assemblages.

Metabolic theory explains latitudinal variation in common carp populations and predicts responses to climate change

Climate change is expected to alter temperature regimes experienced by fishes, which may also alter life history traits. However, predicting population‐level responses to climate change has been difficult. Metabolic theory of ecology has been developed to explain how metabolism controls a variety of ecological processes, including life history attributes. Thus, this theory may be a useful tool for predicting fish population responses to climate change. To understand how climate change may alter freshwater fish life history, we measured population characteristics (e.g., recruitment, growth, body size, and mortality) of 21 North American common carp Cyprinus carpio populations spanning a latitudinal gradient of &gt;2,700 km. We then evaluated (1) how metabolic rates vary with body size and temperature (i.e., metabolic theory of ecology) to interpret latitudinal patterns in life history traits and (2) how predicted increases in annual temperature as a result of climate change may alter metabolism and population characteristics. Common carp growth and mortality decreased whereas fish size and age increased with increasing latitude. Common carp growth rate was 22% faster but mortality was 31% higher for the most southern population compared to the most northern population. Incorporating latitudinal population patterns into metabolic theory of ecology models explained substantial variation in mortality and longevity among populations and suggested that metabolism will increase with temperature according to three global warming scenarios. The greatest metabolic increase occurred at the largest predicted increase in temperature and metabolism increased more for southern populations compared to northern populations. Combined, our findings suggest common carp and other fishes may experience increased growth and metabolic demands but populations may attain smaller body size due to higher mortality in response to climate change.

High female survival promotes evolution of protogyny and sexual conflict.

Existing models explaining the evolution of sexual dimorphism in the timing of emergence (SDT) in Lepidoptera assume equal mortality rates for males and females. The limiting assumption of equal mortality rates has the consequence that these models are only able to explain the evolution of emergence of males before females, i.e. protandry—the more common temporal sequence of emergence in Lepidoptera. The models fail, however, in providing adaptive explanations for the evolution of protogyny, where females emerge before males, but protogyny is not rare in insects. The assumption of equal mortality rates seems too restrictive for many insects, such as butterflies. To investigate the influence of unequal mortality rates on the evolution of SDT, we present a generalised version of a previously published model where we relax this assumption. We find that longer life-expectancy of females compared to males can indeed favour the evolution of protogyny as a fitness enhancing strategy. Moreover, the encounter rate between females and males and the sex-ratio are two important factors that also influence the evolution of optimal SDT. If considered independently for females and males the predicted strategies can be shown to be evolutionarily stable (ESS). Under the assumption of equal mortality rates the difference between the females’ and males’ ESS remains typically very small. However, female and male ESS may be quite dissimilar if mortality rates are different. This creates the potential for an ‘evolutionary conflict’ between females and males. Bagworm moths (Lepidoptera: Psychidae) provide an exemplary case where life-history attributes are such that protogyny should indeed be the optimal emergence strategy from the males’ and females’ perspectives: (i) Female longevity is considerably larger than that of males, (ii) encounter rates between females and males are presumably low, and (iii) females mate only once. Protogyny is indeed the general mating strategy found in the bagworm family.

Coastal Wetland Support of Great Lakes Fisheries: Progress from Concept to Quantification

AbstractFishery support is recognized as a valuable ecosystem service provided by aquatic systems, but it is harder to quantify than to describe conceptually. In this paper, we combine data on fish inhabiting Great Lakes coastal wetlands (GLCWs) with information on commercial and recreational harvest and the piscivore forage base to develop quantitative understanding of the multiple species involved in direct and indirect fishery support of this complex fishery. We then examine patterns of species co‐occurrence and life history and relationships to GLCW conditions in order to identify fishery support metrics useful in aggregating species patterns and evaluating management outcomes. Our criteria for wetland prevalence (≥10% occurrence) and fishery importance (≥1% of recreational or commercial harvest in one or more of the Great Lakes or having a major forage fish role) yielded 21 wetland‐using, fishery‐relevant species representing multiple taxonomic groups and life history attributes. Wetland‐using species are estimated to make up half the biomass and 60% of the dollar value of the fish landed commercially and ∼80% of the fish numbers harvested recreationally. All of the GLCWs studied supported species of interest to recreational and commercial fishers but with widely varying composition. A few key habitat characteristics (e.g., vegetation structure) are broadly predictive of the types of sport and panfish present, with more degraded GLCWs generally supporting abundant but lower‐value taxa (rough‐fish species) and less degraded GLCWs supporting fewer but higher‐value taxa (sport and panfish species). No single taxonomic or functional metric seems adequate to capture the diversity of fishery‐relevant species supported by GLCWs; fishery support needs to be understood and managed in a multimetric context.Received May 16, 2014; accepted October 15, 2014

The weight of fossil leporids and ochotonids: body mass estimation models for the order Lagomorpha

AbstractLagomorphs are widespread around the world, but little is known about the biology and ecology of their fossil ancestors. In this case, knowing the body mass of these extinct species is of principal interest because it is correlated with physiological, morphological and life history attributes. Moreover, insular fossil rabbits, hares and pikas, which became spectacular giants with huge weights and dramatic shifts in their life histories, encourage curiosity in the research world. Our principal aim is to create allometric models between skeletal parameters and body weights with extant species of the order Lagomorpha (both ochotonids and leporids). These regressions can then be applied to the fossil register to estimate the body mass of the extinct lagomorphs. The models are satisfactory in all cases, although weaker relationships were obtained when we analyzed dental parameters. Multiple models have slightly better results than bivariate ones, but their use is limited to complete bones or skeletons. These body mass estimation models were tested in three different fossil lagomorphs: Prolagus apricenicus, Prolagus cf. calpensis and Nuralagus rex. In all three cases, the results from dental variables were discarded due to the fact that these species may not follow the allometric relationship between teeth and body mass of standard lagomorphs. Other variables, such as the proximal anteroposterior diameter of the humerus in N. rex, were also removed for their implications in fossorial lifestyle. We ultimately estimated a weight of around 600 g for P. apricenicus, 300 g for P. cf. calpensis and 8000 g for N. rex. Differences in extrinsic mortality explain the important differences in body masses between the two Prolagus species. The results of N. rex cannot be compared with the giant Prolagus due to phylogenetic differences.

Ontogenetic diet changes and food partitioning of Haemulon spp. coral reef fishes, with a review of the genus diet

The genus Haemulon contains some of the most abundant and ecologically important reef fishes in the South Atlantic Ocean. However, their life history attributes have not been widely studied. Knowledge of ontogenetic changes in their resource use is critical to understanding the processes structuring natural communities. The present study analysed ontogenetic diet changes and food partitioning in Haemulon spp. We collected stomach contents from 276 individuals of four different size classes from four sympatric species (H. aurolineatum, H. parra, H. plumieri and H. squamipinna). There was a significant difference in the proportions of prey types between both species and size classes, providing evidence of food partitioning. Moreover, the Bray–Curtis similarity index revealed two distinct groups. The first consisted of larger-sized fish that consumed larger food items and the second group consisted of smaller individuals that fed on small invertebrates. There was an abrupt shift in the diet of Haemulon spp. at around 10.0 cm total length, a size that corresponds with the greatest morphological changes in the genus. Additionally, the diet overlap calculated by Pianka’s index was more evident in smaller and larger size classes than in intermediate individuals. Together, these observations suggest Haemulon species undergo ontogenetic diet changes and food partitioning within species and size classes that are associated with changes in their habitat use, alongside morphological changes. Further research is needed to determine their ecomorphology and the competitive mechanisms that allow the coexistence of several sympatric and ecologically similar species of the genus Haemulon.

Evidence for facilitation of Culex pipiens (Diptera: Culicidae) life history traits by the nonnative invasive shrub Amur honeysuckle (Lonicera maackii).

Mosquitoes are one of the most globally important insect pests and vectors of human pathogens, and their populations may be facilitated or inhibited by anthropogenic environmental change. Invasive plant species are an important management concern and environmental modifier in many ecosystems; these plant invasions have the potential to exacerbate or diminish mosquito populations. The purpose of this study was to assess potential effects of a highly invasive plant, Lonicera maackii, on a common mosquito species Culex pipiens L., which is an important pathogen vector in the United States. Three microcosm assays were conducted to determine the responses of C. pipiens life history attributes of larval survivorship, growth, and pupation when subjected to leachate from two native plant leaves (Platanus occidentalis and Acer saccharum) and both the leaves and flowers of L. maackii. Only C. pipiens larvae exposed to L. maackii leachate pupated and emerged as adults. However, in all three assays there were statistically significant differences in survivorship and body size change among treatments, and in each assay the highest survivorship and maximum larval size was found in the L. maackii leachate treatments, suggesting positive effects on certain life history traits. This study is one of the first to demonstrate the potential facilitative effect of this invasive plant species on an insect vector and suggests that plant invasion could have positive feedbacks into mosquito population dynamics and, ultimately, human disease.

Soil factors effects on life history attributes of Leiothrix spiralis and Leiothrix vivipara (Eriocaulaceae) on rupestrian grasslands in Southeastern Brazil.

In this study, we hypothesized that the life history traits of Leiothrix spiralis and L. vivipara would be linked to soil factors of the rupestrian grasslands and that rosette size would be influenced by soil moisture. Soil analyses were performed from five populations of L. spiralis and four populations of L. vivipara. In each area, three replicates were employed in 19 areas of occurrence of Leiothrix species, and we quantified the life history attributes. The microhabitats of these species show low favorability regarding to soil factors. During the dry season, their rosettes decreased in diameter due the loss of its most outlying leaves. The absence of seedlings indicated the low fecundity of both species. However, both species showed rapid population growth by pseudovivipary. Both L. spiralis and L. vivipara exhibit a kind of parental care that was quantified by the presence of connections between parental-rosettes and ramets. The findings of the present study show that the life history traits are linked to soil factors.

First confirmed records of Prussian carp, Carassius gibelio (Bloch, 1782) in open waters of North America

Carassius gibelio (Prussian carp) is considered native from central Europe to Siberia and invasive in Asia, Europe, and the Middle East. Todate, there have been no published occurrences of C. gibelio in open waters of North America. Although there are reports from the late 1800’s that C. gibelio was imported into the USA, some doubt exists regarding the identity of those fish and it is unknown whether any were released into the wild. Here we report the first confirmed records of C. gibelio in the wild in North America and estimate its current distribution by compiling records from private and public sources. Morphology and DNA sequences were used to verify identification. Initial specimens of C. gibelio were found in a shallow lake in 2006 in Alberta, Canada. Routine provincial government and private fish surveys from 2008–2014 further identified C. gibelio throughout natural streams and manmade drainage ditches. These surveys document that C. gibelio is now widely distributed throughout southern Alberta. Further spread is likely due to connectivity of the waterways and the lifehistory attributes of this fish.

Predictors of contraction and expansion of area of occupancy for British birds.

Geographical range dynamics are driven by the joint effects of abiotic factors, human ecosystem modifications, biotic interactions and the intrinsic organismal responses to these. However, the relative contribution of each component remains largely unknown. Here, we compare the contribution of life-history attributes, broad-scale gradients in climate and geographical context of species' historical ranges, as predictors of recent changes in area of occupancy for 116 terrestrial British breeding birds (74 contractors, 42 expanders) between the early 1970s and late 1990 s. Regional threat classifications demonstrated that the species of highest conservation concern showed both the largest contractions and the smallest expansions. Species responded differently to climate depending on geographical distribution-northern species changed their area of occupancy (expansion or contraction) more in warmer and drier regions, whereas southern species changed more in colder and wetter environments. Species with slow life history (larger body size) tended to have a lower probability of changing their area of occupancy than species with faster life history, whereas species with greater natal dispersal capacity resisted contraction and, counterintuitively, expansion. Higher geographical fragmentation of species' range also increased expansion probability, possibly indicating a release from a previously limiting condition, for example through agricultural abandonment since the 1970s. After accounting statistically for the complexity and nonlinearity of the data, our results demonstrate two key aspects of changing area of occupancy for British birds: (i) climate is the dominant driver of change, but direction of effect depends on geographical context, and (ii) all of our predictors generally had a similar effect regardless of the direction of the change (contraction versus expansion). Although we caution applying results from Britain's highly modified and well-studied bird community to other biogeographic regions, our results do indicate that a species' propensity to change area of occupancy over decadal scales can be explained partially by a combination of simple allometric predictors of life-history pace, average climate conditions and geographical context.

Variation in seed germination of 134 common species on the eastern Tibetan Plateau: phylogenetic, life history and environmental correlates.

Seed germination is a crucial stage in the life history of a species because it represents the pathway from adult to offspring, and it can affect the distribution and abundance of species in communities. In this study, we examined the effects of phylogenetic, life history and environmental factors on seed germination of 134 common species from an alpine/subalpine meadow on the eastern Tibetan Plateau. In one-way ANOVAs, phylogenetic groups (at or above order) explained 13.0% and 25.9% of the variance in germination percentage and mean germination time, respectively; life history attributes, such as seed size, dispersal mode, explained 3.7%, 2.1% of the variance in germination percentage and 6.3%, 8.7% of the variance in mean germination time, respectively; the environmental factors temperature and habitat explained 4.7%, 1.0% of the variance in germination percentage and 13.5%, 1.7% of the variance in mean germination time, respectively. Our results demonstrated that elevated temperature would lead to a significant increase in germination percentage and an accelerated germination. Multi-factorial ANOVAs showed that the three major factors contributing to differences in germination percentage and mean germination time in this alpine/subalpine meadow were phylogenetic attributes, temperature and seed size (explained 10.5%, 4.7% and 1.4% of the variance in germination percentage independently, respectively; and explained 14.9%, 13.5% and 2.7% of the variance in mean germination time independently, respectively). In addition, there were strong associations between phylogenetic group and life history attributes, and between life history attributes and environmental factors. Therefore, germination variation are constrained mainly by phylogenetic inertia in a community, and seed germination variation correlated with phylogeny is also associated with life history attributes, suggesting a role of niche adaptation in the conservation of germination variation within lineages. Meanwhile, selection can maintain the association between germination behavior and the environmental conditions within a lineage.

Species associations during the succession of wood-inhabiting fungal communities

We studied fungal succession in decaying wood by compiling time-series data of fruit body observations. We tested the hypothesis that the presence of a primary species affects the probability of a succeeding species occurring later on the same log. Significant associations were detected for 15 species pairs; these were consistent with earlier findings on cooccurrence patterns in single time surveys. We used enrichment analysis to test if species with particular life-history attributes were more often associated with the occurrence of a succeeding species, or vice versa. White rot fungi and fungi abundant as mycelia were more often associated with the occurrence of succeeding species, compared to brown rot fungi and species with low mycelial abundance. Our results indicate that certain primary species cause priority effects and non-random co-occurrence patterns in the field. These successional patterns are likely to be connected both with substrate modification and species interactions.