On the population dynamics and ecology of the shrimp species (Crustacea,Decapoda, Natantia) in the Central Amazonian river Tarumã-Mirim

Summary Collections over four years in the habitat of submerged litter show that shrimps are abundant the year round. Mean densities vary from 5–45 animals/m² of litter habitat. Finegrained density distribution within litter sites is highly clumped, but coarse-grained distribution in any given month between litter sites along the river is grosso-modo random.Density and species distribution are a function of the annual cycles of inundations. Of the five species (of a total of seven in the area) that were found to be breeding in the litter habitat it could be established that reproduction is restricted to the period of rising and highest water levels. Reproduction is low in all species, namely below 20 eggs per egg batch with essentially a single generation per year.Breeding ecology in relation to the litter habitat is briefly discussed.This project was supported jointly by the CNPq (Brasilian Research Council), by the OAS (Organization of the American States) and by the SUFRAMA (Financing body of local government)     

Canopy structure and forest understory conditions in a wet Amazonian forest—No change over the last 20 years

Climate change is altering forest dynamics in the tropics, with large potential impacts on forest structure and understory conditions. However, we found that canopy height distribution and openness remained stable over two decades in the western Amazon, and that gap creation rates would need to increase 300% before affecting equilibrium.     

Intra- and interspecific variation in trophic ecology of ‘predatory’ ants in the subfamily Ponerinae

1. The characterisation of energy flow through communities is a primary goal of ecology. Furthermore, predator–prey interactions can influence both species abundance and community composition. The ant subfamily Ponerinae includes many predatory species that range from generalist insectivores to highly specialised hunters that target a single prey type. Given their high diversity and ubiquity in tropical ecosystems, measuring intra- and interspecific variation in their trophic ecology is essential for understanding the role of ants as predators of insect communities. 2. The stable isotopic composition of nitrogen of 22 species from the ant subfamily Ponerinae was measured, relative to plants and other predatory and herbivorous insects at two Atlantic Forest sites in Argentina. The study tested the general assumption that ponerine ants are all predatory, and examined intra- and interspecific variation in trophic ecology relative to habitat, body size and cytochrome c oxidase subunit 1 sequences (DNA barcoding). 3. Stable isotope analysis revealed that most ponerines occupy high trophic levels (primary and secondary predators), but some species overlapped with known insect herbivores. Species residing at low trophic levels were primarily arboreal and may rely heavily on nectar or other plant-based resources in their diet. In addition, larger species tend to occupy lower trophic positions than smaller species. 4. Although some of the species were divided into two or more genetic clusters by DNA barcoding analysis, these clusters did not correspond to intraspecific variation in trophic position; therefore, colony dietary flexibility most probably explains species that inhabit more than one trophic level.     

Comprehensive analysis of the roles of ‘black’ and ‘gray’ clusters in structure and function of rat β-parvalbumin

Recently we found two highly conserved structural motifs in the proteins of the EF-hand calcium binding protein family. These motifs provide a supporting scaffold for the Ca²⁺ binding loops and contribute to the hydrophobic core of the EF-hand domain. Each structural motif forms a cluster of three amino acids called cluster I (‘black’ cluster) and cluster II (‘grey’ cluster). Cluster I is much more conserved and mostly incorporates aromatic amino acids. In contrast, cluster II includes a mix of aromatic, hydrophobic, and polar amino acids. The ‘black’ and ‘gray’ clusters in rat β-parvalbumin consist of F48, A100, F103 and G61, L64, M87, respectively. In the present work, we sequentially substituted these amino acids residues by Ala, except Ala100, which was substituted by Val. Physical properties of the mutants were studied by circular dichroism, scanning calorimetry, dynamic light scattering, chemical crosslinking, and fluorescent probe methods. The Ca²⁺ and Mg²⁺ binding affinities of these mutants were evaluated by intrinsic fluorescence and equilibrium dialysis methods. In spite of a rather complicated pattern of contributions of separate amino acid residues of the ‘black’ and ‘gray’ clusters into maintenance of rat β-parvalbumin structural and functional status, the alanine substitutions in the cluster I cause noticeably more pronounced changes in various structural parameters of proteins, such as hydrodynamic radius of apo-form, thermal stability of Ca²⁺/Mg²⁺-loaded forms, and total energy of Ca²⁺ binding in comparison with the changes caused by amino acid substitutions in the cluster II. These findings were further supported by the outputs of computational analysis of the effects of these mutations on the intrinsic disorder predisposition of rat β-parvalbumin, which also indicated that local intrinsic disorder propensities and the overall levels of predicted disorder were strongly affected by mutations in the cluster I, whereas mutations in cluster II had less pronounced effects. These results demonstrate that amino acids of the cluster I provide more essential contribution to the maintenance of structuraland functional properties of the protein in comparison with the residues of the cluster II.     

Distribution and population structure of four Central Amazonian high-várzea timber species

Amazonian white-water (várzea) floodplains harbor many commercially important timber species which in Brazil are harvested following regulations of the Federal Environmental Agency (IBAMA). Although it is well-known that tree physiology, growth, and species distribution of Amazonian floodplain trees is linked to the heights and durations of the periodical inundations, information about timber stocks and population dynamics is lacking for most tree species. We investigated timber stocks and the population structure of four intensely logged tree species in a western Brazilian várzea forest on an area totaling 7.5 ha. Spatial distribution was investigated in all trees as a function of inundation height and duration and the distance to the river channel, and additionally for saplings (trees <10 cm diameter at breast height––DBH) as a function of the relative photosynthetically active radiation (rPAR). The diameter-class distribution in Hura crepitans and Ocotea cymbarum indicated that populations are subject to density variations that possibly are traced to small-scale flood variability. In all species, saplings concentrated at higher topographic elevations than the mature tree populations, which suggest that the physical ‘escape’ from a flooded environment is an important acclimation to flooding. While Ocotea cymbarum and Guarea guidonia were high-density wood species characterized by random dispersion and a pronounced shade-tolerance, Hura crepitans and Sterculia apetala presented lower wood density, aggregated dispersion, and were more light-demanding. All species presented exploitable stems according to the current harvest regulations, with elevated abundances in comparison to other Amazonian forest types. However, stem densities are below the harvest rates indicating that the harvest regulations are not sustainable. We recommend that the forest management in várzea forests should include specific establishment rates of timber species in dependence of the peculiar site conditions to achieve sustainability.     

Diversity and ecology of desmids of peat bogs in the Jizerské hory Mts

The present study focuses on diversity and ecological preferences of desmids in peat bogs in the Jizerské hory Mts (Czech Republic). Altogether 76 desmid algae taxa have been recorded at 18 sites of the study area during our investigation in 2003–2006. Taxa Actinotaenium crassiusculum (De Bary) Teiling, Hyalotheca dissiliens var. tatrica Racib., Staurastrum avicula var. subarcuatum (Wolle) West & G. S. West, S. borgeanum Schmidle, S. simonyi var. semicirculare Coesel, Staurodesmus extensus var. isthmosus (Heimerl) Coesel, S. extensus var. vulgaris (Eichler & Racib.) Croasdale and S. spencerianus (Mask.) Teiling are new for the Czech Republic. In addition, several rare and remarkable taxa were also encountered. The species richness was relatively high in comparison to similar localities in the Czech Republic. Desmid distribution was influenced by pH and conductivity. Presented at the International Symposium Biology and Taxonomy of Green Algae V, Smolenice, June 26–29, 2007, Slovakia.     

Fragmented living: Behavioural ecology of primates in a forest fragment in the Lopé Reserve, Gabon

A 17-month study was made of the primates using a 9-ha “island” of forest, surrounded by savanna, in the northern part of the Lopé Reserve, Gabon. One group ofCercopithecus cephus (plus a young maleCercopithecus nictitans who was in permanent association with them) were resident in the fragment and groups of five other species of primates made visits during 127 days of observation:Pan troglodytes, 15 visits;Cercocebus albigena, 10;Colobus satanas, 3;Cercopithecus nictitans, 2;C. pogonias, 1. Visits were also made by lone males of three species,C. nictitans, Cercocebus albigena, andMandrillus sphinx. The eighth species of diurnal primate present at Lopé,Gorilla g. gorilla, did not visit the fragment during the study. Compared to conspecific groups in neighbouring continuous forest, primates in the fragment ate less fruit, seeds and flowers and more insects and leaves. The local population density of primates resident in the fragment was equivalent to that of the neighbouring continuous forest where all eight species occur, despite the diversity and abundance of fruit being less in the fragment. The costs imposed on the resident group by the reduced diversity and availability of preferred fruit foods appeared to be offset by a number of benefits that increased individual feeding efficiency for monkeys residing within a single fragment. These included lower travel costs, reduced feeding competition between individuals through group fission, and excellent knowledge of the location and quality of food resources in the small home range. It is also possible that the overall negative impact of inter-specific feeding competition was lower in fragments than in continuous forest and that micro-habitat differences resulted in an increased availability of palatable insect and leaf fallback foods in the fragment.     

Fish faunal ‘breaks’ and stream order in the eastern and central United States

Synopsis The distribution of fishes within 23 streams in the eastern and central United States was analyzed for evidence of distinct longitudinal faunal breaks, and to compare location of the breaks to stream order and longitudinal position of stations within watersheds. On the basis of presence-absence data for fish species, distinct faunal breaks were found in only 8 of the 23 streams. Qualitative faunal breaks were not significantly more common in any particular reach of streams, and the breaks did not correspond to changes in stream order. In 11 of 14 streams for which data on fish abundance were available, quantitative faunal breaks were found, but the locations of these breaks were unrelated to stream order or longitudinal position of stations in streams. Earlier studies have postulated that stream orders may represent distinct biological units for fishes. In contrast, this analysis shows that local fish faunas differ as much within as between adjacent stream orders, and suggests that stream order alone is not a pervasive organizer of lotic fish communities.     

Latitudinal and elevational patterns of phylogenetic structure in forest communities in China’s mountains

Science China Life Sciences - The phylogenetic structure incorporates both ecological and evolutionary processes to explain assembly of a local community. The “phylogenetic niche...     

On the ‘transmission sense of information’

In order to illuminate the role of information in biology, Bergstrom and Rosvall (Biol Philos 26:159–176, 2011a; Biol Philos 26:195–200, 2011b) propose a ‘transmission sense of information’ which builds on Shannon’s theory. At the core of the transmission sense is an appeal to the reduction in uncertainty in receivers and to etiological function. I explore several ways of cashing out uncertainty reduction as well as the consequences of appealing to function.     

On the correct use of ‘data’

Acknowledgement  Thanks are due to Drs. Paul Johnston (P.Johnston@ exeter.ac.uk) and E. William Beese (ebeese@t-online.de) for kindly providing dictionary definitions and for sharing their thoughts about the correct use of ‘data’.     

Fine structure of the ‘Wulst’ region of the domestic fowl in organotypic cultures

Summary Parts of the Wulst region of the chick embryo brain were maintained for 39 days in vitro. Processes of adjacent glial cell form zonulae occludentes and desmosomal junctions in the uppermost stratum of the cultures. Subjacent to this layer, in the neuropil, axodendritic synapses are abundant. 10–20 m below the surface the perikarya of glial cells and neurons are found. The latter form small clusters, plasma membranes of contiguous cells being directly apposed to each other. Axosomatic synapses terminate on the perikarya. Occasionally one terminal synapses on two nerve cells simultaneously. Two types of cilia arise from basal bodies in the cytoplasm of nerve cells. Type I is a slender protrusion of about 0.5 m in diameter, extending into the neuropil. On transverse sections it displays a 9 + 0 pattern of organization of paired micro tubules proximally, and an 8 + 1 configuration more distally. The length of the cilium is approximately 7 m. Type II cilia also originate in the neuronal cytoplasm. The structure of the proximal portion is identical with that of type I cilia. Toward the tip, however, the type II cilium is characterized by a bulbous enlargement which is filled with loosely folded membranes. The fine structural details of this cilium correlate closely to the outer segments of retinal photoreceptor cells during differentiation. The possible role of a light receptor in the Wulst region of birds, controlling biological rhythms, is discussed. Acknowledgements. The authors wish to thank Mrs. H. Frenk for her expert assistance in tissue culture and electron microscopic techniques     

Role of the EXPO ’70 forest project in forest restoration in urban areas

The forest-restoration project of EXPO ’70 Commemorative Park, Japan, is an epoch-making attempt to restore a nature-oriented forest park in an urban area in which large-scale land reclamation had occurred. The objective of this paper is to review the concept, planning, and design, and the outcome so far, and discuss current aspects of creating a core natural habitat in the city of Osaka. Innovative planning policy and design methods have been used for construction of the forest-restoration project of EXPO Park. Unexpected troubles have occurred, however. After approximately 10 years severe effects of poor drainage and soil compaction on the establishment of the forest have been revealed by intensive monitoring. Partial redevelopment and soil-amendment work has therefore been conducted. These improvements seemed to have resulted in “a self-sustaining forest”, the original objective of the planning policy. After approximately 25 years, however, a second intensive monitoring program has revealed that the status of nature restoration is generally favorable in quantity but not in structure of forest communities or biodiversity. The major issues identified are excessive tree density with a single foliage layer caused by the single generation of immature forest stand, and ecological isolation from the source of nature. The EXPO forest is currently in the “Second Generation” stage; this involves management, including artificial gap regeneration, and soil seed bank introduction, with careful monitoring. The project is expected to be an ideal example of a core habitat of nature-oriented forest in urban areas achieved by adaptive management.     

Eukaryotic microbiota in the surface waters and sea ice of the Southern Ocean: aspects of physiology, ecology and biodiversity in a ‘two-phase’ ecosystem

The Southern Ocean provides a habitat for microplankton which is strongly influenced by physical factors. Of these, one of the most important and striking is the formation of sea ice. Organisms in the ice form a unique community with specific properties and adaptations. Material and organisms are exchanged between the water column and the ice during the annual cycle, and ice is an important factor in modifying biogeochemical processes and exchange between ocean and atmosphere. The coupled system, in which a range of organisms alternate between a fluid and a solid medium, provides an interesting exercise in community ecology, and has implications for the assessment of biodiversity in understanding large-scale change.     

A constructional account of French -clé ‘key’ and Dutch sleutel- ‘key’ as in mot-clé / sleutelwoord ‘key word’

The article studies the status of French clé ??key?? and Dutch sleutel ??key?? which are recurrent in complex nouns such as mot-clé / sleutelwoord ??keyword??, notion-clé / sleutelbegrip ??key notion?? and figure-clé / sleutelfiguur ??key figurè. In spite of the semantic similarities between the two elements, both occurring in similar compound-like constructions, it is shown that the degree of cohesion of N-clé and sleutel-N widely differs. More particularly, whereas sleutel forms cohesive NN compounds, clé can be observed in adjectival contexts, in the same way as its English counterpart key (e.g. un r?le absolument clé ??an absolutely key rolè??, ce livre est absolument clé ??this book is absolutely key??, etc.). This paradox is dealt with within the theoretical framework of Construction Grammar.     

Anatomical structure and gravitropic response of the creeping shoots of ground-cover chrysanthemum ‘Yuhuajinhua’

The chrysanthemum cultivar ‘Yuhuajinhua’ has a creeping habit. The anatomy and distribution of amyloplasts within ‘Yuhuajinhua’ stems were compared to those typical of non-creeping cultivars. ‘Yuhuajinhua’ stems are similar to those of conventional cultivars; but except for the pith, the proportion of the various tissues present in the upper side of stems was higher than that in the lower side. Most of the amyloplasts lie in the centre of the endodermal cells of the ‘Yuhuajinhua’ stems, rather than at the bottom, as is typical for non-creeping cultivars. When ‘Yuhuajinhua’ plants were oriented horizontally and kept in the dark, the stems retained their original growth direction, and the endodermis amyloplasts sedimented according to the gravitational direction. The endodermis amyloplasts responded rapidly to gravistimulation. The content of IAA in the upper side of the ‘Yuhuajinhua’ stems was higher than that in the lower side, associated with the assymetric growth of the stems.