Ecological relations between mangrove leaf litter and the spatial distribution of the gastropod Melampus coffeus in a fringe mangrove forest

Leaf litter represents a food source to many organisms that may directly contribute to organic matter decomposition. In addition, the physical presence of these vegetal detritus contributes for the modification of some environmental areas and produce microhabitats that may act as a refuge against predators and desiccation for many animals. The pulmonate gastropod Melampus coffeus (Linnaeus, 1758) (Ellobiidae) is a very common specie in Atlantic Coast mangrove forests and feeds on fallen mangrove leaves. It was hypothesized that the spatial distribution of Melampus coffeus is directly affected by mangrove leaf litter biomass deposition. Thus, this research aimed at evaluating the spatial distribution of these gastropods in relation to the biomass of mangrove leaf litter through a twelve-month period. The study area was established in the middle estuary of Pacoti River, state of Ceará, Brazil where two adjacent zones with different topographic profiles were determined. Samples of Melampus coffeus and leaf litter were collected monthly, throughout a year, from the mangrove ground surface. The results indicated that the presence of twigs in mangrove litter favor the occupation by smaller individuals of M. coffeus, probably because smaller individuals are more susceptible to predator attacks and desiccation than larger ones, and twigs and branches may provide a safe microhabitat.

Composition and ecological patterns of snake assemblages in an Amazon-Cerrado Transition Zone in Brazil

ABSTRACT The present study encompasses the species composition and ecological characteristics of the snake community in a Cerrado-Amazon transition zone in Midwest of Brazil (state of Mato Grosso). The data were collected during six excursions to the "Tanguro" (study area) by visual encounter survey, pitfall traps with drift fences and non-systematic sampling. We collected 194 specimens, distributed in 34 species, 26 genera, and eight families. The most abundant species were Crotalus durissus Linnaeus, 1758 (n = 50), Philodryas olfersii (Lichtenstein, 1823) (n = 15), Philodryas nattereri Steindachner, 1870 (n = 13), Xenodon rabdocephalus (Wied, 1824) (n = 12), Lachesis muta (Linnaeus, 1766) (n = 10) and Erythrolamprus almadensis (Wagler, 1824) (n = 10). The composition of species found here represents a combination of Cerrado and Amazonian savanna fauna.

An ecological and comparative analysis of parasites in juvenile Mugil liza (Pisces, Mugilidae) from two sites in Samborombón bay, Argentina

ABSTRACT Mugil liza Valenciennes, 1836 is an economically important food fish and has been recommended for aquaculture in South America. A total of 278 fishes were collected in the spring and summer of 2009 and 2010. These fish were sorted into sample groups according to their size class. We used Bayesian statistics and 95% credible intervals for each parameter tested were calculated. Fish studied harbored a total of 15 different species of parasites. Diversity of parasite species found on Mugil liza was greatest at the S.R.C. collection site, but evidenced a lower species richness than at A.R. site. The 1st size fishes of both sites evidenced greater parasite diversity than either 2nd or 3rd size fish. Differences observed could be explained by the different use of habitat types at the two sites or differential susceptibility to infection by parasites. The dominance of D. fastigatainfluenced observed results of lower community diversity indexes. New works elucidating different parasite life cycles within juvenile and adults ofM. liza in Argentina, promise to be important for determining the risk of the parasitism by zoonotic metacercariae A. (P.) longa and use of this fish as food and an economic resource, and the possible use of mullet parasites in other promising fields as indicators of biodiversity, and/ or water contamination.

Metabolic profiles of countries and ecological distribution conflicts.

"Social metabolism" is a notion that links up the natural sciences and the social sciences, and also human history. Work has been done by some groups in Europe in order to operationalize the old idea of looking at the economy from the point of view of "social metabolism". This paper is an attempt to consider the links between each society’s characteristic metabolic profile and the ecological distribution conflicts, at different scales (international, national, regional).

Conscious procreation: neo-malthusianism in southern Europe and Latin America in around 1900

One main concern of Ecological Economics is the balance between human population and natural resources. This is rightly named the Malthusian question because Malthus predicted that human populations, if unchecked, would grow exponentially while agricultural production (and other land-based productions) would be subject to decreasing returns to the labour input. This article shows that over one hundred years ago, there was in Europe and America a successful social movement that called itself Neo-Malthusianism. In contrast to Malthus’ pessimism, it believed that population growth could be stopped among the poor classes by voluntary decisions. Women were entitled to choose the number of children they wanted to have. The movement did not appeal to the State to impose restrictions on population growth. On the contrary, in Southern Europe it was based on "bottom up" activism against governments and the Catholic Church.

Embedding theorems of funcitional classes, III

In this paper we obtain the necessary and sufficient conditions for embedding results of different function classes. The main result is a criterion for embedding theorems for the so-called generalized Weyl-Nikol'skii class and the generalized Lipschitz class. To define the Weyl-Nikol'skii class, we use the concept of a (λ,β)-derivative, which is a generalization of the derivative in the sense of Weyl. As corollaries, we give estimates of norms and moduli of smoothness of transformed Fourier series.

Empiricism in ecological economics: a perspective from complex systems theory

Economies are open complex adaptive systems far from thermodynamic equilibrium, and neo-classical environmental economics seems not to be the best way to describe the behaviour of such systems. Standard econometric analysis (i.e. time series) takes a deterministic and predictive approach, which encourages the search for predictive policy to ‘correct’ environmental problems. Rather, it seems that, because of the characteristics of economic systems, an ex-post analysis is more appropriate, which describes the emergence of such systems’ properties, and which sees policy as a social steering mechanism. With this background, some of the recent empirical work published in the field of ecological economics that follows the approach defended here is presented. Finally, the conclusion is reached that a predictive use of econometrics (i.e. time series analysis) in ecological economics should be limited to cases in which uncertainty decreases, which is not the normal situation when analysing the evolution of economic systems. However, that does not mean we should not use empirical analysis. On the contrary, this is to be encouraged, but from a structural and ex-post point of view.

Ecological economics

Ecological economics is a recently developed field, which sees the economy as a subsystem of a larger finite global ecosystem. Ecological economists question the sustainability of the economy because of its environmental impacts and its material and energy requirements, and also because of the growth of population. Attempts at assigning money values to environmental services and losses, and attempts at correcting macroeconomic accounting, are part of ecological economics, but its main thrust is rather in developing physical indicators and indexes of sustainability. Ecological economists also work on the relations between property rights and resource management, they model the interactions between the economy and the environment, they study ecological distribution conflicts, they use management tools such as integrated environmental assessment and multi-criteria decision aids, and they propose new instruments of environmental policy.

Ecological conflicts and valuation - mangroves vs. shrimp in the late 1990s

Shrimps are produced in two different ways. They are fished in the sea (sometimes at the cost of turtle destruction) or they are "farmed" in ponds in coastal areas. Such aquaculture is increasing around the world as shrimps become a valuable item of world trade. Mangrove forests are sacrificed for commercial shrimp farming. This paper considers the conflict between mangrove conservation and shrimp exports in different countries.Who has title to the mangroves, who wins and who loses in this tragedy of enclosures? Which languages of valuation are used by different actors in order to compare the increase in shrimp exports and the losses in livelihoods and in environmental services? The economic valuation of damages is only one of the possible languages of valuation which are relevant in practice. Who has the power to impose a particular language of valuation?

A vegetação no município de Ilhéus Estado da Bahia: IV - Caracaterísticas analíticas e periodicidade sociológica

It is well-known that diverse groups of vegetation with an analogous but not identical floristic composition show an ecological similarity which leads to a determined type of vegetation. Starting from this fact it becomes evident that the scope of phytosociological work is the establishing of the significance of the species within the association and the discovery of the rules which govern associations. The floristic surveys made in the field have to be analysed statistically so as to obtain satisfactory results. The usefulness of this method depends largely on the possibilities of comparing the results with previous studies of the same kind, in the same country, or elsewhere. The method used in this paper is that of measuring circumferences and counting individuals in the different associations studied because it permits the presentation of the results in tables which show the phytosociological complexity of the Brazilian rain-forests. The classical method of characteristics is valuable because the more evolved an association is the less sociable are the species it contains, so that such groups do not show clear differences between species but rather between sinusia or strata of individuals. Five tables are presented in which several of the qualitative and quantitative characteristics are studied with a view to discussing their value in relation to groups and species. They are: I - Abundance (number of individuals). II - Density (distance in meters between the individuals belonging to each stratum). III - Basal coverture (circles measured in square meters of the mean projection of the individuals on the surface). IV - Basal area (mean circle in square meters occupied by individuals on the surface). V - Frequency, abundance and sociability in relation to occurrence. TABLE I. This table indicates first the number of individuals in relation to the sinusia studied: next, the sum total of the individuals belanging to the strata are given for each association, thus providing the numeric value of the sinusia: finally, the relation between the total number of individuals in the association and the total for the sinusium thus fursnishing the abundance per sinusium, in the classic sence, that is the percentage, or rather the relative number, of the elements which compose the group. CONCLUSIONS. The general character of abundance of the regional vegetation of Ilheos may be summed up in the following way: as an association evolves towards permanent equilibirum the number of individuals the inferior strata diminishes in relation to those of the superior strata which increase. For the shrub sinusium, two important facts were observed: a) in a given association the number of elements of the inferior strata diminishes as the diameter of the individuals increases; b) the percentage of individuals belonging to the shrub sinusium in the sere diminishes as the association evolve. In the subarboreal sinusium it is seen that: in the sere the number of subarboreal individuals does not vary much; whereas in the climax or the prisere there is a fall owing to the equilibrum of the biologic forms. In the arboreal sinusium the following conclusion can be deduced from analogous facts: the number of individuals of the lower strata diminishes as circumference increases. Also, in the sere there is a progressive sequence for the individuals belonging to the superior strata. TABLE II. The relation between the mean distances of individuals belonging to the same stratum and the area of an association is equal to the density. The table shows that the mean density of the association and the distance between the individuals belonging to the strata of the same sinusium in relation to the total number of individuals belonging to the association. CONCLUSIONS. As rule, the density of individuals in the associations studied follows a very general character or at least a regional one: the distance between the individuals in the diverse strata varies according to their abundance and sociability. Two other facts of some sociological importance are: a) in identical strata of the same sere the density of individuals oscillates in an analogous manner in teh subclimaces and varies in the stages which have reached equilibrium. b) the density of individuals varias in accordance with the sinusium and the distances between individuals of the same sinusium varg in accordance with the strata. TABLE III. This table presents the mean basal individual coverture, that is the mean projection of the frond of the various individuals belonging to the same stratum. The means were obtained by measurement in the field, of 100 individuals belonging to each stratum and their projection on the surface. In the latoratory these measurements were converted into mean circles (in square meters) and the result was multiplied by the individuals belonging to the strata corresponding to the sinusium of each association. The result obtained is named basal coverture. CONCLUSIONS. As a rule, the basal coverture of the vegetation of the county of Ilhéus indicates that: in the evolution of the vegetation the basal coverture of the arbustive sinusium diminishes progressively whereas that of the arboreal one increases. The special norms obtained are: 1) in the shrub sinusium the basal coverture seems to follow a uniform norm, that is, in stages of evolution of the subclimax the basal coverture oscillates with a certain uniformity. 2) in the subarboreal sinusium this fact is related to the vitality and age of the species, as in the subclimax the number of young trees is large and the vitality of the species very variable. This permits the conclusion that: in the sere the basal coverture increases with the evolution of the vegetation and diminishes when an equilibrium is reached. 3) in the tree sinusium the climax association of the prisere and subsere seem to obey a binomial rule, as the coverture (density-abundance) increases until a determined stratum is reached and...

Embedding theorems of function classes, IV

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As condições ecológicas da Cephaelis ipecacuanha Rich

The present paper is a simple introduction to the ecological requirements of Cephaelis ipecacuanha and only a few preliminary conclusions are reached. Cephaelis ipecacuanha has the habit of a forest plant, which is closely connected with the meteorological and floristic factors. This makes it very necessary to study its ecolo-gical relationships carefully, so as to understand its productivity in accordance with its mi¬croclimatic and microedaphic reactions. Conclusions: 1 — Within the ecological range of Cephaelis ipecacuanha, some zones show more fa¬vourable phytosociological conditions than other zones. Consequently, the vegetative and biological types must be investigated in different associations. a — The most favourable vegetative and biological types encountered, in regard to the phytosociological characteristcs of Cephaelis ipecacuanha, were found respectively in the rain forest on the slopes of the Serra dos Parecis and in the serclimax of the river Galera and its tributaries. b — The phytosociological optimum of Cephaelis ipecacuanha was seen in the Vochysietum (Vochysia sp.) which corresponds to number 11 of the original text. It can be defined as follows: shading by vegetation approximately 90%, as the herbaceous sinusium covers 90% of the area worked in, though the arboreal and arbustive coverture is only 65% and 60% respectviely. The inclination is pratically nil (less than 5°) but the drainage is good because the soil is deep and silicous-humous, thus facilitating infiltration by the rain water which inundates the ground temporarily during the periods of floods. The pH oscillates between 5 and 6, denoting a slightly acid soil.