Temperature Influence on Species Co-Occurrence Patterns in Treefall Gap and Dense Forest Ant Communities in a Terra- Firme Forest of Central Amazon, Brazil

In this study we evaluated the influence of temperature and species co-occurrence on the structure of an ant community of treefall gaps and surrounding dense forests in a terra-firme forest of Central Amazon, Brazil. For this, we collected ants at different hours, and at the time of each collection we measured the temperature of the environment. Even with the difference in the temperature variation and variation throughout the day, there was no difference in the richness and abundance of ants among the environments. Also, the ant species are distributed randomly and independently of one another in both studied environments in accordance with a null model (C-score). However, although not influenced by temperature, the ant composition of treefall gaps was different from the ant community of the surrounding dense forest. Possibly the composition and ant foraging in environments of treefall gaps and surrounding dense forests are not only influenced by temperature, but also by the interaction of this factor with the structural complexity of vegetation in terms of sites available for nesting and feeding, and other microclimatic factors. This generates a difference in ant composition of both environments. In addition, the structuring of ant community in tropical rain forests may actually be stochastic or neutral within each environment

Defining Habitat Use by the Parabiotic Ants Camponotus femoratus (Fabricius, 1804) and Crematogaster levior Longino, 2003

Ant-garden ants have a strong relationship with epiphytes that need light to grow, for these reason, it has been previously documented in forest gaps. Moreover, larger gaps have more available area for nesting and habitats for use as forage. Thus we hypothesize that 1) canopy openness influence the presence of ant´s gardens in gaps, and 2) greater gaps will have more nests, and 3) both openness canopy and area determine the colony size in forest gaps. Furthermore, it is known that parabiotic ants foraging on the ground and in vegetation, the nests are arboreal. So, we also hypothesize that 4) parabiotic ants are more often sampled in arboreal strata and 5) increasing vegetation connectivity and the volume of accumulated litter in the soil increase the foraging of the ants in vegetation and ground, respectively, with the increase in canopy openness increasing the activity of the two species in both strata. Presence, number of Ant-gardens, as colony size, was affected by area and locality, but not by canopy openness. Nevertheless, there was not overall difference in the use of strata by Camponotus femoratus, neither by Crematogaster levior. On the other hand, frequency of C. femoratus on the ground decreases with canopy openness but is not affected by the vegetation connectivity.  Also, C. levior frequency on the ground also decreases with the increase of complexity of vegetation and canopy openness. In addition, neither vegetation connectivity, or canopy openness influence the frequency of foraging of these ants in understory

Les donations

L'Avant-projet traite des donations en les présentant comme un des contrats nommés. La matière des libéralités, dans le projet de Code civil du Québec, est fragmentée entre les successions, pour les testaments, et les obligations, pour les donations. L'article présente une étude systématique et comparative avec le droit actuel de la législation proposée en la matière. Il souligne les aspects restés inchangés, les modifications apportées, les ambiguïtés ou lacunes des textes proposés. Pour ce faire, il a souvent fallu se référer à d'autres parties de l'Avant-projet, puisque les donations ne sont plus présentées que comme un contrat nommé parmi les autres. Mais la présentation suit le plan traditionnellement suivi par la doctrine en la matière : notion de libéralités, conditions de fond et deforme, effets des donations et enfin donations par contrat de mariage. Ceci permet de souligner pour chacun des points principaux les similitudes et différences avec le droit actuel selon une présentation connue des lecteurs. Ainsi, la notion de libéralité reste inchangée. On semble avoir voulu généraliser le don manuel à tous les biens meubles, sans qu'il soit certain, cependant, que l'on soit parvenu à ce résultat. On a omis d'émettre en plusieurs points les règles générales, laissant ainsi place à des difficultés d'application ou d'interprétation. lien est ainsi par exemple pour ce qui est de la forme des donations, de l'obligation aux dettes et de la définition des différents types de donation.The Draft Bill deals with gifts by presenting them as nominate contracts. Matters pertaining to liberalities in the proposed Québec Civil Code are divided between successions for wills and obligations for gifts. The article presents a systematic and comparative study of proposed legislation on gifts within the context of existing law. It underscores areas that remain unchanged, amendments made as well as ambiguities or omissions in proposed texts. To do this, it was often necessary to refer to other parts of the Drafts Bill, since gifts are only presented as being one nominate contract among other such contracts. Otherwise the presentation follows the traditional pattern found in doctrinal studies on the matter : the notion of liberality, conditions of substance and form, effects of gifts and, lastly, gifts by contract of marriage. This makes it possible to highlight each of the main points converging with or diverging from present law in a way that is familiar to readers. Thus the concept of liberality remains unchanged. There seems to have been a will to generalize the gift by delivery to all movable property — without it being evident that such result has been obtained. General rules have not been expounded into a sufficient number of points such that there may be room for difficulties in enforcement and interpretation. For instance, this occurs in matters pertaining to the form of gifts, obligations with regard to debts and the definition of varying types of gifts

Amazon Rainforest Ant-Fauna of Parque Estadual do Cristalino: Understory and Ground-Dwelling Ants

Ants are ecologically dominant and have been used as valuable bio-indicators of environmental change or disturbance being used in monitoring inventories.  However, the majority of inventories has concentrated in ground-dwelling ant fauna disregarding the arboreal fauna. This paper aimed to list the ant species collected both on the ground and in the vegetation of the Parque Estadual do Cristalino, an important protected site in the center of the southern Amazon. Moreover, we compared the composition of the ground dwelling and vegetation foraging ants. Was sampled 203 species distributed among 23 genera and eight subfamilies, wherein 35 species had not yet been reported in the literature for Mato Grosso State. As expected, the abundance and richness of ants was higher on the ground than in the understory. Also, the ant assemblages composition was different between these habitats (with only 20% occurring in both). It indicate that complementary methods which include arboreal and terrestrial ants are indicated for efficient inventory. This study provides an inventory of the arboreal and ground ant fauna contributing to the knowledge and conservation of ant fauna of the Amazonian

Postponing the production of ant domatia as a strategy promoting an escape from flooding in an Amazonian myrmecophyte

Background and Aims: Even when adapted to flooding environments, the spatial distribution, growing strategies and anti-herbivore defences of plants face stressful conditions. Here we describe the effects of flooding on carbon allocation on growth, domatia and leaf production, and the herbivory on the myrmecophyte domatia-bearing Tococa coronata Benth. (Melastomataceae) growing along river banks in the Amazon region. Methods: In an area of 80 000 m2 of riparian forest along the Juruena River we actively searched for individuals of T. coronata. In each plant we evaluated the size of the plant when producing the first domatium and determined its best predictor: (1) plant total height; (2) size of plants above flood level; or (3) length of time each plant spent underwater. We also compared the herbivory, internode elongation, foliar asymmetry and specific leaf weight between T. coronata individuals growing above and below the maximum flooding level. The distance to the river and the height of the first domatium produced were compared between T. coronata and its sympatric congener, T. bulifera. Key Results: We found that T. coronata invests in rapid growth in the early ontogenetic stages through an elongation of internodes rather than in constitutive anti-herbivore defences to leaves or domatia to exceed the maximum flooding level. Consequently, its leaf herbivory was higher when compared with those produced above the flooding level. Individuals with leaves above flood levels produce coriaceous leaves and ant-domatias. Thus, flooding seems to trigger changes in growth strategies of the species. Furthermore, T. coronata occurs within the flood level, whereas its congener T. bullifera invariably occurs at sites unreachable by floods. Conclusion: Even in conditions of high stress, T. coronata presents both physiological and adaptive strategies that allow for colonization and establishment within flooded regions. These mechanisms involve an extreme trade-off of postponing adult plant characteristics to rapid growth to escape flooding while minimizing carbon allocation to defence

Gustavo Schwartz

ABSTRACT -Stressed plants are generally more attacked by galling insects. In this study we investigated the relationship between population abundance and species richness of galling insects on the tree Alchornea castaneaefolia A. JUSS. (Euphorbiaceae), submited to stress induced by the hemiparasite Psittacanthus sp. (Loranthaceae) in the Amazon, Brazil. Branches of A. castaneaefolia attacked by the hemiparasite were more heavily infested by galling insects than non-attacked branches. The field observations partially corroborate the hypothesis that there would be an optimal level of host-plant stress for galling insect establishment

Interaction Intimacy Affects Structure and Coevolutionary Dynamics in Mutualistic Networks

The structure of mutualistic networks provides clues to processes shaping biodiversity [1-10]. Among them, interaction intimacy, the degree of biological association between partners, leads to differences in specialization patterns [4, 11] and might affect network organization [12]. Here, we investigated potential consequences of interaction intimacy for the structure and coevolution of mutualistic networks. From observed processes of selection on mutualistic interactions, it is expected that symbiotic interactions (high-interaction intimacy) will form species-poor networks characterized by compartmentalization [12, 13], whereas nonsymbiotic interactions (low intimacy) will lead to species-rich, nested networks in which there is a core of generalists and specialists often interact with generalists [3, 5, 7, 12, 14]. We demonstrated an association between interaction intimacy and structure in 19 ant-plant mutualistic networks. Through numerical simulations, we found that network structure of different forms of mutualism affects evolutionary change in distinct ways. Change in one species affects primarily one mutualistic partner in symbiotic interactions but might affect multiple partners in nonsymbiotic interactions. We hypothesize that coevolution in symbiotic interactions is characterized by frequent reciprocal changes between few partners, but coevolution in nonsymbiotic networks might show rare bursts of changes in which many species respond to evolutionary changes in a single species. © 2007 Elsevier Ltd. All rights reserved