The impact of red howler monkey latrines on the distribution of main nutrients and on topsoil profiles in a tropical rain forest

Scarcity of organic matter and nutrients in the topsoil is a typical feature of lowland primary tropical rain forests. However, clumped defecation by vertebrate herbivore troops and further dung beetle processing may contribute to locally improve soil biological activity and plant growth. We studied the impact of clumped defecation by the red howler monkey (Alouatta seniculus), a frugivorous primate, on the vertical distribution of topsoil (0–6 cm) main nutrients and microstructures in a tropical rain forest (French Guiana). Three latrines, where monkey troops regularly defecate, were sampled, together with adjoining controls for carbon, nitrogen, phosphorus and microscopic components. The vertical distribution of C and N was affected by clumped defecation: nutrients were mostly restricted to the top 2 cm in control areas while latrines exhibited homogeneously distributed C and N, resulting in higher C and N content below 2 cm. No marked effect of defecation was registered on Olsen P. A small although significant increase in pH (0.1–0.3 pH units) and a marked increase in soil respiration (×1.5–2.5) were registered in latrines. Soil microstructures were studied by the small‐volume method. Variation according to depth, site and clumped defecation was analysed by Redundancy Analysis. The three latrines were characterized by an increase in root‐penetrated mineral‐organic assemblages, mainly composed of recent and old earthworm faeces. The local stimulation of plant roots, microbial and earthworm activity was prominent, together with an increase in soil fertility. Consequences for the regeneration of tropical rain forests in the Amazonian basin were discussed, in the light of existing knowledge.     

Dissolved carbon leaching from soil is a crucial component of the net ecosystem carbon balance

Estimates of carbon leaching losses from different land use systems are few and their contribution to the net ecosystem carbon balance is uncertain. We investigated leaching of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and dissolved methane (CH₄), at forests, grasslands, and croplands across Europe. Biogenic contributions to DIC were estimated by means of its δ¹³C signature. Leaching of biogenic DIC was 8.3±4.9 g m^?2 yr^?1 for forests, 24.1±7.2 g m^?2 yr^?1 for grasslands, and 14.6±4.8 g m^?2 yr^?1 for croplands. DOC leaching equalled 3.5±1.3 g m^?2 yr^?1 for forests, 5.3±2.0 g m^?2 yr^?1 for grasslands, and 4.1±1.3 g m^?2 yr^?1 for croplands. The average flux of total biogenic carbon across land use systems was 19.4±4.0 g C m^?2 yr^?1. Production of DOC in topsoils was positively related to their C/N ratio and DOC retention in subsoils was inversely related to the ratio of organic carbon to iron plus aluminium (hydr)oxides. Partial pressures of CO₂ in soil air and soil pH determined DIC concentrations and fluxes, but soil solutions were often supersaturated with DIC relative to soil air CO₂. Leaching losses of biogenic carbon (DOC plus biogenic DIC) from grasslands equalled 5–98% (median: 22%) of net ecosystem exchange (NEE) plus carbon inputs with fertilization minus carbon removal with harvest. Carbon leaching increased the net losses from cropland soils by 24–105% (median: 25%). For the majority of forest sites, leaching hardly affected actual net ecosystem carbon balances because of the small solubility of CO₂ in acidic forest soil solutions and large NEE. Leaching of CH₄ proved to be insignificant compared with other fluxes of carbon. Overall, our results show that leaching losses are particularly important for the carbon balance of agricultural systems.     

Nitrogen oxide gas emissions from temperate forest soils receiving long-term nitrogen inputs

From spring 2000 through fall 2001, we measured nitric oxide (NO) and nitrous oxide (N₂O) fluxes in two temperate forest sites in Massachusetts, USA that have been treated since 1988 with different levels of nitrogen (N) to simulate elevated rates of atmospheric N deposition. Plots within a pine stand that were treated with either 50 or 150 kg N ha^?1 yr^?1 above background displayed consistently elevated NO fluxes (100–200 µg N m^?2 h^?1) compared to control plots, while only the higher N treatment plot within a mixed hardwood stand displayed similarly elevated NO fluxes. Annual NO emissions estimated from monthly sampling accounted for 3.0–3.7% of N inputs to the high‐N plots and 8.3% of inputs to the Pine low‐N plot. Nitrous oxide fluxes in the N‐treated plots were generally < 10% of NO fluxes. Net nitrification rates (NRs) and NO production rates measured in the laboratory displayed patterns that were consistent with field NO fluxes. Total N oxide gas flux was positively correlated with contemporaneous measurements of NR and concentration. Acetylene inhibited both nitrification and NO production, indicating that autotrophic nitrification was responsible for the elevated NO production. Soil pH was negatively correlated with N deposition rate. Low levels (3–11 µg N kg^?1) of nitrite () were detected in mineral soils from both sites. Kinetic models describing NO production as a function of the protonated form of (nitrous acid [HNO₂]) adequately described the mineral soil data. The results indicate that atmospheric deposition may generate losses of gaseous NO from forest soils by promoting nitrification, and that the response may vary significantly between forest types under similar climatic regimes. The lowering of pH resulting from nitrification and/or directly from deposition may also play a role by promoting reactions involving HNO₂.     

A new genus of filicalean fern from the Lower Permian of China

Recent investigation on the Cathaysian flora of the Lower Permian Taiyuan Formation in Hebei Province, North China has led to the discovery of a new type of fern, Rastropteris pingquanensis gen. et sp. nov. Preserved as a permineralization, the stem, with a mantle of petiole bases and roots, shows a unique combination of anatomical characters. The vascular strand consists of a solid protostele with uniformly elongated tracheids and mesarch maturation of the xylem. In transverse section, the configuration of leaf trace xylem changes from reniform endarch to a tangentially elongated strand adaxially recurved at each end with several adaxial ridges. Stem and petiole cortex contains abundant sclerotic tissue with an interstitial tissue developed within the mantle of petiole bases and roots. A reinvestigation of Grammatopteris rigollotii , from the Permian of France, the type species of the genus allows interpretation of the latter as closer to Rastropteris than any other fern. Both taxa are provisionally reported to an incertae sedis group of filicalean ferns possibly involved in the origin of Osmundaceae.     

Influence of Protein Factors on the Activation of NADP–malate Dehydrogenase by Dithiothreitol

Leaves of Phaseolus vulgaris L. contained malate dehydrogenase activity dependent on NADP (E. C. 1.1.1.82); it could be detected in extracts only when a dithiol such as dithiothreitol was present. After the addition of dithiothreitol, the activity increased with time, passed through a maximum and then diminished. The activation rate and/or the maximum level of activity were essentially dependent on dithiothreitol concentration, pH, and temperature. The presence of bovine serum albumine or glycerol in the medium decreased the inactivation rate; equivalent results were obtained at low temperatures. A mathematical model was established showing an apparent first-order rate for activation and inactivation only under conditions of alkaline pH near 8.3. These data allowed us to demonstrate that compounds other than dithiothreitol were necessary for the activation process. Evidence suggested that these compounds were protein factors of low molecular weights which increased the activation rate and the maximum level of activity when added to the incubation medium at pH 7.3. Their efficiency in the enzyme activation was higher at alkaline pH than at acid or neutral pH.     

An anatomical investigation of calcicolous endolithic lichens from the Trieste karst (NE Italy)

ABSTRACT

The anatomy of five endolithic lichens (Acrocordia conoidea, Petractis clausa, Rinodina immersa, Verrucaria baldensis, and V. marmorea) from the Trieste Karst (north-eastern Italy) was thoroughly investigated. Samples already used in previous ecophysiological studies were examined by histological and mineralogical techniques, and by SEM. Biomineralisation products were searched for by X-ray diffractometry, X-ray microdiffractometry, and Fourier Transformed Infrared spectrophotometry. The results confirm that the photobiont layer is located approximately at the same depth in the substratum, although the species occur in habitats with strongly different light regimes; the thallus development is relatively constant within populations of a single species, but differs considerably among species. Several peculiarities of each species were revealed, such as the presence of large clews of hyphae in the inner layer of P. clausa, forming large voids in the substratum, or the development of morphologically different oil-hyphae. Calcium oxalate crystals were not detected. Some terms currently used to describe the anatomy of endolithic lichens are critically discussed, and the new term “lithocortex” and “pseudo-medulla” are introduced.     

The complex nature of progenetic species — examples from Mesozoic ammonites

Several examples of progenetic species among Mesozoic ammonites are investigated. The ammonites are Middle Jurassic kosmoceratids, Upper Jurassic oppeliids, and Upper Cretaceous scaphites. As assessed through outgroup comparison, the progenetic species in each of these examples is characterized by small size at maturity and the presence of morphological features typical of those of the juveniles of more primitive species. However, in none of these examples is the progenetic species a duplicate form of the juvenile stage of more primitive species. There are at least three kinds of features of progenetic species that differ from those of the juveniles of more primitive species: (1) symplesiomorphous features associated with maturation, (2) unique features whose presence is not clearly related to progenetic processes, and (3) unique features that may represent epigenetic outgrowths of juvenile morphology. This novel combination of juvenile. adult. and unique features may endow progenetic species with the evolutionary potential to play a role in the origin of higher taxa. □ Progenesis, heterochrony, Ammon-oidea. Jurassic, Cretaceous.     

A phylogenetic study of the neotropical catfish family Cetopsidae (Osteichthyes, Ostariophysi, Siluriformes), with a new classification

A hypothesis on the phylogenetic relationships of the neotropical catfish family Cetopsidae is proposed on the basis of the parsimony analysis of 127 morphological characters and most of the species currently recognized. The family and its two recognized subfamilies, the Cetopsinae and Helogeninae, are corroborated as monophyletic, in agreement with recent studies. Previously proposed classifications of the Cetopsinae, however, were found to be poorly representative of the phylogenetic relationships within the subfamily. Major generic rearrangements are implemented in order that the classification of the Cetopsinae reflects the phylogenetic hypothesis. Pseudocetopsis Bleeker (1862) was found to be polyphyletic and to include several disjunct lineages. One of these lineages, recently named as the genus Cetopsidium Vari, Ferraris, and de Pinna (2005), is the sister group to the rest of the Cetopsinae. Denticetopsis Ferraris (1996) is the next sister group to the remainder of the Cetopsinae. The remaining species of the Cetopsinae belong to one of two sister genera, Paracetopsis Bleeker (1862) and Cetopsis Spix and Agassiz (1829). The latter genus includes species formerly assigned to Hemicetopsis Bleeker (1862), Bathycetopsis Lundberg and Rapp Py‐Daniel (1994) and Pseudocetopsis Bleeker (1862). Continued recognition of Hemicetopsis and Bathycetopsis would have required the creation of several additional new genera for various species previously in Pseudocetopsis that form a series of sister groups to a clade composed of Cetopsis oliveirai (Lundberg and Rapp Py‐Daniel, 1994), C. coecutiens (Lichtenstein, 1819) and C. candiru (Spix and Agassiz, 1829). Cetopsis oliveirai is a highly paedomorphic species that displays surprising similarities with conditions in juvenile specimens of C. coecutiens, a species that attains a large body size. Such similarities are not evident in adult specimens of the latter species. A new classification is proposed, within which the subfamily Cetopsinae consists of three tribes, the Cetopsidiini, the Cetopsini and the Denticetopsini. The results of the study form the basis for a discussion of the phylogenetic position of the family within the Siluriformes, the phylogenetic biogeography of the Cetopsidae, paedomorphosis and gigantism in the family, and the effect of different semaphoronts on the intrafamilial phylogeny. Journal compilation © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society, 2007, 150 , 755–813. No claim to original US government works.     

Morphometric analysis and taxonomic revision of Anisopteromalus Ruschka (Hymenoptera: Chalcidoidea: Pteromalidae) – an integrative approach

We use an integrative taxonomic approach to revise the genus Anisopteromalus. In particular, we apply multivariate ratio analysis (MRA), a rather new statistical method based on principal component analysis (PCA) and linear discriminant analysis (LDA), to numerous body measurements and combine the data with those from our molecular analysis of Cytb and ITS2 genetic markers (on a subset of species) and all available published data on morphology, karyology, behaviour, host associations and geographic distribution. We demonstrate that the analysis of quantitative characters using MRA plays a major role for the integration of name‐bearing types and thus for the association of taxa with names. Six species are recognized, of which two are new: A. cornis Baur sp.n. and A. quinarius Gokhman & Baur sp.n. For Anisopteromalus calandrae (Howard), a well‐known, cosmopolitan parasitoid of stored‐product pests, we have selected a neotype to foster continuity and stability in the application of this important name. The species was sometimes confused with the related A. quinarius sp.n. , another cosmopolitan species that is frequently encountered in similar environments. We also show that several species originally described or later put under Anisopteromalus actually belong to different genera: Cyrtoptyx camerunus (Risbec) comb.n. ; Meraporus glaber (Szelényi) comb.n. ; Dinarmus schwenkei (Roomi, Khan & Khan) comb.n. Neocatolaccus indicus Ayyar & Mani is confirmed as a junior synonym of Oxysychus sphenopterae (Ferrière) syn.n. and Anisopteromalus calandrae brasiliensis (Domenichini) stat.rev. must be considered as a valid but doubtful taxon. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:BDFE96D3‐D0F4‐4012‐90F5‐9A087F7F5864 .     

A fast,highly sensitive double‐nested PCR‐based method to screen fish immunobiomes

Efficient methods for constructing 16S tag amplicon libraries for pyrosequencing are needed for the rapid and thorough screening of infectious bacterial diversity from host tissue samples. Here we have developed a double‐nested PCR methodology that generates 16S tag amplicon libraries from very small amounts of bacteria/host samples. This methodology was tested for 133 kidney samples from the lake whitefish Coregonus clupeaformis (Salmonidae) sampled in five different lake populations. The double‐nested PCR efficiency was compared with two other PCR strategies: single primer pair amplification and simple nested PCR. The double‐nested PCR was the only amplification strategy to provide highly specific amplification of bacterial DNA. The resulting 16S amplicon libraries were synthesized and pyrosequenced using 454 FLX technology to analyse the variation of pathogenic bacteria abundance. The proportion of the community sequenced was very high (Good’s coverage estimator; mean = 95.4%). Furthermore, there were no significant differences of sequence coverage among samples. Finally, the occurrence of chimeric amplicons was very low. Therefore, the double‐nested PCR approach provides a rapid, informative and cost‐effective method for screening fish immunobiomes and most likely applicable to other low‐density microbiomes as well.