Taxonomic Membership Research Articles

Dualite, Na30(Ca,Na,Ce,Sr)12(Na,Mn,Fe,Ti)6Zr3Ti3MnSi51O144(OH,H2O,Cl)9, a new zircono-titanosilicate with a modular eudialyte-like structure from the Lovozero alkaline Pluton, Kola Peninsula, Russia

Dualite has been found at Mount Alluaiv, the Lovozero Pluton, the Kola Peninsula in peralkaline pegmatoid as sporadic, irregularly shaped grains up to 0.3–0.5 mm across. K-Na feldspar, nepheline, sodalite, cancrinite, aegirine, alkaline amphibole, eudialyte, lovozerite, lomonosovite, vuonnemite, lamprophyllite, sphalerite, and villiaumite are associated minerals. Dualite is yellow, transparent or translucent, with conchoidal fracture. The new mineral is brittle, with vitreous luster and white streaks. The Mohs hardness is 5. The measured density is 2.84(3) g/cm3 (volumetric method); the calculated density is 2.814 g/cm3. Dualite dissolves and gelates in acid at room temperature. It is nonfluorescent. The new mineral is optically uniaxial and positive; ω = 1.610(1), ɛ = 1.613(1). Dualite is trigonal, space group R3m. The unit cell dimensions are a = 14.153(9), c = 60.72(5) A, V = 10533(22) A, Z = 3. The strongest reflections in the X-ray powder pattern [d, A (I,%)(hkl)] are as follows: 7.11(40)(110), 4.31(50)(0.2.10), 2.964(100)(1.3.10), 2.839(90)(048), 2.159(60)(2.4.10, 0.4.20), 1.770(60)(2.4.22, 4.0.28, 440), 1362(50)(5.5.12, 3.0.42). The chemical composition (electron microprobe, H2O calculated from X-ray diffraction data) is as follows, wt %: 17.74 Na2O, 0.08 K2O, 8.03 CaO, 1.37 SrO, 0.29 BaO, 2.58 MnO, 1.04 FeO, 0.79 La2O3, 1.84 C2O3, 0.88 Nd2O3, 0.20 Al2O3, 51.26 SiO2, 4.40 TiO2, 5.39 ZrO2, 1.94 Nb2O5, 0.58 Cl, 1.39 H2O,-O = 0.13 Cl2; they total is 99.67. The empirical formula calculated on the basis of 106 cations as determined by crystal structure is (Na29.79Ba0.1K0.10)Σ30(Ca8.55Na1.39REE1.27Sr0.79)Σ12 · (Na3.01Mn1.35Fe 0.87 2+ Ti0.77)Σ6(Zr2.61Nb0.39)Σ3 (Ti2.52Nb0.48)Σ3(Mn0.82Si0.18)Σ1(Si50.77Al0.23)Σ51 O144[(OH)6.54(H2O)1.34·Cl0.98]Σ8.86). The simplified formula is Na30(Ca,Na,Ce,Sr)12(Na,Mn,Fe,Ti)6Zr3Ti3 MnSi51O144 (OH,H2O,Cl)9). The name dualite is derived from Latin dualis (dual) alluding to the dual taxonomic membership of this mineral, which is at the same time zirconosilicate and titanosilicate. The crystal structure is characterized by two module types (alluivite-like and eudialyte-like) alternating along a threefold axis with a doubled c period relative to eudialyte and close chemical affinity to rastsvetaevite (Khomyakov et al., 2006a) and labyrynthite (Khomyakov et al., 2006b). According to the authors’ crystal chemical taxonomy of the eudialyte group, the new mineral belongs to one of three subgroups characterized by a 24-layered structural framework. Dualite is a mineral formed during the final stages of peralkaline pegmatite formation. The type material of dualite is deposited at the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow.

Germination time, other plant traits and phylogeny in an alpine meadow on the eastern Qinghai-Tibet plateau

In this paper, 633 species (involving 10 classes, 48 families, 205 genera) collected from the alpine meadow on the eastern Qinghai-Tibet plateau were studied. We tested potential factors affecting variation in mean germination time (MGT), i.e., plant traits (adult longevity, dispersal mode and seed size) or phylogeny, to evaluate if these factors were independent or they had interaction. Nested ANOVA showed that taxonomic membership accounted for the majority of MGT variation (70%), and in the generalized linear model, family membership could explain independently the largest proportion of MGT variation (29%). The strong taxonomic effect suggests that MGT variation within taxonomic membership is constrained. The other plant traits could also explain MGT variation independently (1% by adult longevity and dispersal mode, respectively, and 2% by seed size). Thus, the phylogeny was an important constraint to maintain the stability of species, and we could simplify the question if we regarded the phylogeny as an individual factor, but we could not negate the adaptive significance of the relationship between other plant traits and seed MGT. In addition, a large percentage of the variance remained unexplained by our model, thus important selective factors or parameters may have been left out of this analysis. We suggest that other possible correlates may exist between seed germination time and additional ecological factors (for example, altitude, habitat and post-dispersal predation) or phylogenetic related morphological and physiological seed attributes (e.g., endosperm mass) that were not evaluated in this study.

Seed mass and germination in an alpine meadow on the eastern Tsinghai–Tibet plateau

In this study, we built up a database of 570 species from an alpine meadow on the eastern Tsinghai–Tibet plateau. We examined the correlation of seed mass and germination with phylogeny, habitat and altitude, and the relationship between seed mass and germination. We found that: habitats had no significant effects on seed mass and germinability, which was in accord with the former studies; there was a significant negative correlation between seed mass and altitude, as well as between germinability and altitude, which was opposite to most of the former studies; there was a significant negative correlation between seed mass and germinability, which was in contrast with other studies that have found a positive relationship, and seed mass could explain 24.1% of total variation in germinability; in GLM, family and genus accounted for 43.9% and 83.9% of total variation in seed mass, and 34.1% and 65.4% in germinability, respectively, thus, it was evident that seed mass and germinability were strongly related to phylogeny. We considered that seed mass and germination might be the result of both selective pressures over long-term ecological time and the constraints over long-standing evolutionary history of the taxonomic membership. We suggest that correlates of ecology and phylogeny should be taken into account in comparative studies on seed mass and germination among species.

Ecogeographical stability and climate forcing in the Late Miocene (Vallesian) rodent record of Spain

The composition and structure of rodent taxocenosis from three Iberian basins with a reasonably complete record (Calatayud–Teruel, Duero and Vallès–Penedès) for the latest Aragonian and Vallesian (Middle–Late Miocene) is explored using Correspondence Analysis (CA). CA classifies the assemblages in four great groups that are interpreted as rodent paleocommunity types (RPTs). On the basis of paleobotanical and paleomastological data available for some of the sites considered (or time-equivalent localities) each RPT is considered to be characteristic of certain environmental conditions. Taxonomic membership and relative abundance patterns in the recognized RPTs are quite stable throughout relatively long time intervals in each basin, suggesting the existence of coordinated stasis. However, the predictions of coordinated stasis are only partly achieved, and important differences are shown to occur within certain RPTs. RPTs with a low species richness and dominated by one or two genera characterize the record of the Duero Basin. In the case of the Vallès–Penedès and Calatayud–Teruel more equitative RPTs with a high species richness are present during the Early Vallesian (and also during the latest Aragonian in the Vallès–Penedès). The Late Vallesian sites appear as clearly differentiated of the remaining ones and grouping is strongly influenced by geographic position. The environment seems to have been more open and wet–dry seasonal in the Late Vallesian sites of the Calatayud–Teruel and Duero basins. Instead in the Vallès–Penedès Basin it appears to have been more humid and cool–warm seasonal. This fact points to the existence of a zonation of the Iberian climate during the Late Vallesian that closely matches the pattern observed today.

Ecological Correlates of Flowering Seasons in Korean Angiosperms

Ecological correlates of flowering times often are examined to infer evolutionary mechanisms for flowering time diversities. We examined ecological characteristic associations such as growth habits and pollination modes with flowering times among 3,037 Korean angiosperms experiencing strong climatic seasonalities. We first examined taxonomic membership effects on flowering times across diverse taxonomic levels. Phylogeny constrained flowering times at all levels down to the genus level. We then analyzed the effects of ecological characteristics using subset data consisting of species randomly selected from each genus to control phylogenetic effects. The commonly observed patterns of early flowering of woody species in temperate regions existed. Spring flowering shrubs and trees, however, both being woody, were involved with biotic and abiotic vectors, respectively. In two herbaceous groups of annuals and perennials, annuals flowered later in the growing season than perennials although both herbs tended to be associated with abiotic vectors when flowering in autumn. These results support our hypothesis that species able to decouple vegetative and reproductive growth flower in spring's dry season, but species with different habits, even when they flower within the same season, are subjected to different selective pressures for efficient pollination.

A QUANTITATIVE STUDY OF BENTHIC FAUNAL PATTERNS WITHIN THE PENNSYLVANIAN AND EARLY PERMIAN

Abstract Using abundance data, this study explores quantitative patterns from marine benthos, including implications for paleogeography, depositional environment, stratigraphic position, taxonomic groups (brachiopod or mollusc), substrate preferences, and ecological niches. Twenty-nine brachiopod- and bivalve-dominated fossil assemblages from the Pennsylvanian and Early Permian of North and South America, Thailand, and Australia were analyzed from carbonate-platform environments; specifically, Nevada, Kansas, Oklahoma, Texas, Utah, New Mexico, Venezuela, Kanchanaburi (Thailand), and Queensland (Australia). Samples were categorized by paleogeographic location, depositional environment, and age to help differentiate factors controlling the faunal patterns. Pooled from primary and summary literature resources, 336,321 specimens were identified to genus level and classified in terms of taxonomic membership, substrate preference, and ecological niche. Data were analyzed using detrended correspondence analysis ...

More than numbers matter: The effect of social factors on behaviour and welfare of laboratory rodents and non-human primates

With the development of laboratory animal science, increasing attention has been given to the possible influence of housing and husbandry on the behaviour and welfare of laboratory animals as well as on the scientific integrity. With the present paper, we aim to contribute to this knowledge by reviewing existing literature on how social factors influence laboratory rodents and non-human primates. We use social ecology in the wild as a starting point to understand experimental studies of these social species. Laboratory studies show that preweaning social experiences, and lack thereof, affect the development of social skills and capacity to cope with stressful situations in both primates and rodents. Studies of deprivation, of preference and of demand indicate that both rodents and primates are highly motivated to interact with conspecifics. When housed alone, rodents and primates typically show a more ‘anxious’ reaction in behaviour tests, and are more profoundly affected by certain stressors, although there seem to be some differences in how rodent males and females react to different social situations. However, for social housing to be beneficial for the animals, compatible and stable groups are crucial. When forming groups of monkeys in captivity, the age and sex of individuals and their relative age difference, the taxonomic membership of the animals as well as the introductory technique are factors of importance for success. Kinship is also of importance for the compatibility of both rodent and primate groups. Social instability through changes of group composition is apparently stressful, resulting in behavioural and physiological alterations in both rodents and primates. The effects of social conditions around testing have been given much less attention, but several studies show that animals react differently in behaviour tests when tested in group than when tested individually. Altogether, the most commonly used laboratory rodents and primates belong to social species, and their behaviour and welfare are strongly affected by previous and present social environment. Factors such as group composition and stability, rank and previous social experience therefore need to be taken into account both when designing housing systems and when planning experiments and interpreting results.

Nectar Concentration and Composition of 26 Species from the Temperate Forest of South America

Floral nectar concentration and chemical composition of 26 plant species native to the temperate forest of southern South America are reported and the relationships with the flower type are evaluated. Nectar concentration was measured with a hand refractometer and sugar composition was analysed by gas-liquid chromatography. Plant species were classified into flower type categories based not only on floral features but also on data from the literature and field observations on their pollinators. Most data on nectar are new reports at the generic and/or specific level. Plant species in which more than one population was studied showed significant among-population variation in nectar sugar concentration and composition. Results showed a weak relationship between nectar traits and flower type. Many species had nectar containing 50 % or more sucrose (17 of 26 species), independent of the main pollinator. Considering that (a) nectar characteristics did not show a clear association with different flower types or with plant taxonomic membership, and (b) different populations of the same species showed large variability in sugar composition, the results suggest that other factors (e.g. historical and environmental) could be involved in determining the sugar composition of the highly endemic plant species from this region.

Folk Classification and Capability Assessment of Soils in Two Highland Guatemalan Municipios

Fieldwork involving the elicitation of folk classification and capability assessments of soils was conducted in seven small communities within the Guatemalan highlands, with the original goal of searching for complementarities between scientific and folk soil classification systems. While locals' classification of soils share certain commonalities with scientific classification systems, they differ in at least two aspects: 1) Unlike soil classification systems such as Soil Taxonomy, local classification does not display exclusive relations of taxonomic membership; and 2) local soil classification reflects greater concern with managing soils for crop production than with natural processes of soil landscape development. However, local farmers are aware of soil-landscape-plant relationships that impact soil suitability for crop production. This awareness is best exemplified through an explanation of the criteria that peasant farmers in this highland tropical setting use when applying concepts of "hot" and "cold" to assess soil productivity. An analysis of farmer explanations of the criteria that they use when referring to a particular soil as being "hot" or "cold" indicates the ecological sophistication of local concepts of soil-landscape-plant relationships among both indigenous (Kaqchikel Maya) and non-indigenous (Ladino) peasant farmers within the Guatemalan highlands. El trabajo de campo para elicitar la clasificaci�n popular y una evaluaci�n de la capacidad de suelos fue conducido en siete peque�as comunidades dentro de la sierra guatemalteca, con el prop�sito original de buscar las complementaridades entre los sistemas de clasificaci�n cient�fica y popular. Mientras la clasificaci�n de los campesinos de las localidades comparte algunos aspectos comunes con el sistema cient�fico, hay por lo menos dos diferencias: 1) a diferencia de los sistemas de clasificaci�n como la taxonom�a de suelos, la clasificaci�n popular no muestra relaciones exclusivas de membres�a taxon�mica; y 2) la clasificaci�n popular refleja m�s preocupaci�n por el manejo de los suelos para la producci�n que por los procesos naturales de desarrollo del suelo. Sin embargo, los campesinos son concientes de la relaci�n suelo-plantas con impacto en la conveniencia del suelo para producci�n. Esta conciencia est� mejor ejemplificada a trav�s de la explicaci�n de los criterios que campesinos utilizan en este contexto de la sierra tropical cuando ellos aplican los conceptos de "caliente" y "frio" en la evaluaci�n de la productividad del suelo. Esto indica una sofisticaci�n de conceptos locales de las relaciones entre suelos y plantas tanto dentro el grupo ind�geno (Kaqchikel Maya), como del grupo no-ind�geno (Ladino).

Flowering patterns among angiosperm species in Korea: diversity and constraints

Because of the complexities of their flowering parameters, it is difficult to make generalizations about flowering phenology among temperate angiosperms. We examined patterns of flowering time and duration among 2867 Korean angiosperm species, and these patterns were associated with climatic factors. The effect of taxonomic membership was also tested. Overall data pooled over species from 165 families showed that 63.8% of these angiosperms flowered in summer, 19.5% in spring, 16.5% in autumn, and 0.2% in winter. Summer and autumn flowering periods were significantly longer than springtime events. Both mean monthly temperature and precipitation were strongly positively correlated with the number of species in flower, but not with flowering duration. The seven largest families differed in their flowering season and duration; both parameters were also segregated among genera within large families. In a two-way analysis, both flowering season and family membership exerted significant effects on flowering duration. These results demonstrate that the evolutionary influence on flowering time and duration can be observed at the community level when two factors are considered, i.e., the interaction of flowering parameters and the taxonomic composition of species within those communities.

Development of a meiobenthic nematode community following the intertidal placement of various types of sediment

A field experiment was conducted at an intertidal mudflat in SE England to investigate processes affecting the development of meiobenthic nematode assemblages in response to the placement of different types of sediment, simulating the deposition of fine-grained maintenance dredged material for habitat creation. Natural assemblages were exposed to different types of substrate, including sediment with natural sand and organic content (defaunated control), sediment with elevated sand content (high sand content treatment) and sediment with elevated organic content (high organic content treatment) for a period of 12 months. Differences between colonising assemblages and those from ambient control sediment in terms of total nematode abundance, taxonomic membership (i.e. number of species, species composition) and size (i.e. total biomass, biomass size spectra) were most marked in the plots with elevated organic content. Nematode density, number of species and total biomass in the defaunated control and high sand content treatment came to resemble those in the ambient control sediment after 3 months. In the organically enriched sediment, values only attained background level at the end of the experiment. Multivariate analyses revealed that, although assemblage structure in all treatments, and in particular the defaunated control and the high sand content treatment, became increasingly similar to the ambient sediment over time, recovery to ambient condition had not occurred 1 year after the set-up of the experiment.

Scale-dependent variation in competitive ability among encrusting Arctic species

Finding evidence for climate change in the sea has been less easy than on land. As ice- loading of nearshore waters (through ice sheet collapses) seems a most likely signal of climate warm- ing, we looked at communities likely to be affected by changing disturbance, i.e. those encrusting boulders in shallow water. The structures of such assemblages at high latitude are highly hierarchi- cal in which if uninterrupted by disturbance (ice-scour) succession would lead to domination by just a single species. However, unless pecking orders from place to place involve the same specific spe- cies, with the same competitive rankings, monopolisation will remain only local. To see how pecking orders varied, we examined variability in competitive performance of common species in a high Arc- tic lithophillic assemblage at several spatial scales. These were sampled 10 1 , 10 3 and 10 5 m apart on the west coast of Spitsbergen, and 10 6 m apart, achieved by sampling southern Iceland and the Faeroe islands. We found that higher taxonomic membership was the major factor determining over- growth performance of species. Overgrowth performance of each study species changed relatively little between samples, the same good competitors being top performers in any samples where they occurred. Overgrowth performance of each study species was also most similar in samples at the smallest spatial scale. Apart from this, the performance of each study species did not, however, become more dissimilar with increasing distance between samples. Most noteworthy was that sus- ceptibility to variation in overgrowth performance at the regional 10 5 m scale altered with competi- tive ranking, i.e. pioneer and dominant species lost and won nearly all encounters respectively, wher- ever they were. The performance of mid-ranking species was much more variable. These results suggest that whilst the patterns of succession may differ from place to place, the end results will not. Our study provides data to support the theory that appreciation of scale is crucial to understanding community structure, diversity and potential for response to climate change. If ice-loading (distur- bance) in polar waters does decrease, we suggest from our findings that a very small number of encrusting species may monopolise large areas of the shallows. Before this, though, we predict that different mid-ranked species will become more common from site to site, with limited reduction of ice (disturbance) increasing regional diversity.

Statistical testing of community patterns: uppermost Hamilton Group, Middle Devonian (New York State: USA)

We present an extensive and rigorously controlled quantitative paleoecological study within an interval of inferred coordinated stasis. This Middle Devonian Hamilton Group study completes a 20-yr project by providing data within the unresolved upper Hamilton Group section. Together with other rigorously controlled studies, these data sets have the potential to address the larger question of coordinated stasis in the fossil record. We collected data from the Windom Member, Moscow Formation (uppermost Hamilton Group), to test different statistical approaches to define paleocommunities. We evaluate various techniques, including non-parametric multidimensional scaling and agglomerative hierarchical clustering to decipher community patterns. Additionally, we advocate regular use of cluster significance testing along with ANOSIM (i.e. analysis of similarities) when examining ecological data. Together these techniques test the significance of sample groups more rigorously than conventional testing (e.g. discriminant analysis or analysis of variance (ANOVA)). Our results indicate that communities within this upper Hamilton Group interval exhibit variable taxonomic membership within a relatively stable ecological structure.

A comparative study of interspecific variation in fruit size among Australian eucalypts

We examined variation in woody fruit size among 362 Australian Eucalyptus species with respect to predictions relating fruit size to fire exposure and rainfall. Predictions for fruit size variation were established that focussed on selection for small or large seeds, given a positive allometric relationship between fruit and seed size within the genus, and on the potential for fruits to protect their valuable seed contents. Comparatively smaller fruits were found in species that continually experience frequent disturbance by fire, while both small and large fruits were found among species subjected to both short and long fire intervals. In the latter case where a broad range of fire intervals is possible, some species have adopted a strategy of producing small seeds that provide superior colonisation ability in disturbed conditions, while other species have adopted a strategy of producing large seeds which are more competitive during longer intervals between disturbance by fire. Only when taxonomic membership at the subgeneric level was accounted for in analyses across all species, did a significant relationship emerge between fruit size and rainfall independently of fire interval and plant height; comparatively larger fruits were found in species experiencing lower average annual rainfall in the subgenera Eucalyptus and Symphyomyrtus. In contrast to previous studies, larger fruits were found only in short species, while small fruits were found in both short and tall species. Many short species have adopted a strategy of protecting their seeds from high fire intensity by producing larger fruit. Since tall species can elevate their fruit far above high fire intensity, they make considerable energy savings by producing smaller fruit. It remains an open question as to why small fruit size occurs in some short species, but we suggest that these species may invest more heavily in vegetative regrowth after fire than in re‐establishment by seed.

Seed Size and Phylogeny in Six Temperate Floras: Constraints, Niche Conservatism, and Adaptation

Seed size is correlated with a number of other plant attributes, and such correlations are commonly interpreted as adaptations to different life histories. However, seed size is also strongly related to species phylogeny. In the current comparative literature, correlations between trait variation and taxonomic membership are often interpreted as evidence for phylogenetic constraints, and such phylogenetic explanations of variation are presented as alternatives to adaptive explanations. However, phylogenetic patterns of trait variation should not be discussed exclusively in terms of constraints. Neither should phylogenetic and adaptive explanations for variation be automatically presented as alternatives. Another explanation for similarity among related taxa is phylogenetic niche conservatism (PNC). This process is well known to exist-indeed, it is an inevitable consequence of evolution by natural selection-and is explicitly adaptive. Under PNC, radiation within a lineage is shaped by phylogeny, by the env...

Seed mass of Indiana Dune genera and families: Taxonomic and ecological correlates

Several surveys have documented an association among species between habitat type and seed mass, suggesting that habitat attributes impose a direct selective force on seed mass. Previous comparative surveys, however, have not controlled for the statistical effects of shared phylogenetic history (at the genus or family level) and life form when evaluating the relationship between habitat and seed mass. This study of the Indiana Dunes angiosperm flora provides statistical ‘control’ of genus and family membership by: (i) partitioning out the statistical effect of genus membership prior to measuring the effect of habitat on seed mass, and (ii) seeking an association between habitat and seed mass within eight genera (206 species) and ten families (366 species). To measure the associations between ecological factors, taxonomic membership and seed mass, I examined life form, phenological schedules and seed mass among species in 8 genera distributed among 13 habitat types (assigned to 1 of 4 categories of inferred water and light availability). One-way ANOVAS indicated that genus, life form, habitat, water/light category, the onset of flowering and the duration of flowering accounted for 71%, 51%, 10%, 4%, 14% and 14% of the variance in seed mass, respectively. However, multi-factor ANOVAS measured the variance in seed mass accounted for by each variable independently of the others: only genus explained a significant proportion (11%). Genus membership is strongly associated with the other ecological factors, accounting for the difference between one-way and multi-factor ANOVAS. Within the ecologically widespread genera and families of this study, there was no significant association between water/light category and seed mass, even though this association can be detected across taxa. Among congeners and confamilials, interspecific variation in seed mass (measured as the coefficient of variation) was as high within habitat types as among them, suggesting that habitats do not provide upper limits to the range of seed mass exhibited by the species within them. A previous study of 648 Indiana Dune species showed that species segregate among habitats on the basis of seed size; large-seeded species tend to occupy closed habitats and small-seeded species tend to inhabit open habitats. This segregation creates the ecologically meaningful observation that low-light habitats support larger-seeded species than high-light habitats, even though this pattern cannot be detected independently of taxonomic membership. Generalist taxa may occupy a wide range of habitats for reasons other than their seed size. If this is a common feature of ecological generalists, it may not be possible to detect an association between habitat and seed size independently of taxonomic membership.