Antimicrobial activity in methanolic extracts of several plant species from northern Argentina

I analyzed nest site preferences and whether these preferences were linked to nest success of five bird species breeding in an arid area of southern South America. Most nests (90%) were located in three plant species (Geoffroea decorticans, Capparis atamisquea, and Atriplex lampa). Serpophaga griseiceps, Poospiza ornata, and P. torquata nested in plants with size significantly different from randomly selected plants. At the mesohabitat scale (i.e., habitat patch surrounding the nest), four species showed clear differences from random patches within the general habitat, and the remaining species (Saltatricula multicolor) showed a non-significant trend. The daily survival rate of S. griseiceps nests placed in the preferred plant species (i.e., G. decorticans) was lower than those in the other nest-plants. In the other four bird species, nest survival did not differ between preferred and other plants used for nesting. At the scale of microhabitat (i.e., plant size and location of the nest inside the plant), no significant differences were detected between unsuccessful and successful nests. Similarly, unsuccessful nest patches did not differ significantly in habitat features from those that were successful. High nest predation rates found in this habitat (around 85% for the total assemblage) and a relatively high diversity of predators (and of predation tactics) appear to impede the presence of “safe” sites for nesting (i.e., there are trade-offs between avoidance strategies).

Pollination ecology of Geoffroea decorticans (Fabaceae) in central Argentine dry forest

Abstract. In southern humid Chaco forests dominated by Schinopsis balansae, woody plants are clumped and species composition varies spatially over short distances. We examined how these spatial patterns are associated with local environmental heterogeneity for three size classes of woody individuals: adults, saplings, and seedlings. Our study was based on the detailed description of two forest plots (3200 m2 in total) in which we mapped all individuals of woody species, and delimited patches with different microrelief, soil moisture, and ground cover of terrestrial bromeliads. Our results showed that woody‐individual distribution is related to local environmental heterogeneity. For all size classes, density of woody individuals was highest on convex patches. These convex patches were dominated by both tree (Acacia praecox and Achatocarpus praecox) and shrub species (Celtis pallida, Capparis retusa and Grabowskia duplicata), while level patches were dominated only by tree species (Schinopsis balansae, Prosopis spp. and Geoffroea decorticans). Drier patches contained all the woody species present in the forest, while wetter patches contained only a subset of them. Within convex patches, trees are likely to occur in places with bromeliad colonies and shrubs in patches without bromeliads. The results suggest forest structure is controlled by environmental heterogeneity associated with microrelief and soil moisture.

Abstract Seeds of 17 wild leguminous species belonging to the Papilionoideae subfamily were analysed for their proximate, fatty acid and sterol compositions. Centrosema virginianum, Tipuana tipu, Adesmia volckmanni and some species of Desmodium contained high amounts (>300 g kg−1) of protein. Geoffroea decorticans and Clitoria cordobensis were noteworthy for their high oil content (>350 g kg−1). The seed lipids had a high proportion of unsaturated (oleic and linoleic mainly) fatty acids. Linolenic acid had the highest value in Adesmia volckmanni (25.4% of total fatty acids). β‐Sitosterol was the major component of the sterol fraction. Chemical analyses indicated that all species studied are suitable sources of animal feed.© 2002 Society of Chemical Industry

In southern humid Chaco forests dominated by Schinopsis balansae, woody plants are clumped and species composition varies spatially over short distances. We exam- ined how these spatial patterns are associated with local envi- ronmental heterogeneity for three size classes of woody indi- viduals: adults, saplings, and seedlings. Our study was based on the detailed description of two forest plots (3200 m 2 in total) in which we mapped all individuals of woody species, and delimited patches with different microrelief, soil mois- ture, and ground cover of terrestrial bromeliads. Our results showed that woody-individual distribution is related to local environmental heterogeneity. For all size classes, density of woody individuals was highest on convex patches. These convex patches were dominated by both tree (Acacia praecox and Achatocarpus praecox) and shrub species (Celtis pallida, Capparis retusa and Grabowskia duplicata), while level patches were dominated only by tree species (Schinopsis balansae, Prosopis spp. and Geoffroea decorticans). Drier patches contained all the woody species present in the forest, while wetter patches contained only a subset of them. Within convex patches, trees are likely to occur in places with bromeliad colonies and shrubs in patches without bromeliads. The results suggest forest structure is controlled by environmental hetero- geneity associated with microrelief and soil moisture.

Compositional Studies of Seeds and Fruits from Two Varieties of Geoffroea decorticans

Proximate, fatty acid and sterol compositions of the oil were determined to ascertain the general characteristics of the seed and seed oil of Geoffroea decorticans (Leguminosae) originating from central area of Argentina. Proteins represented 21.6% (w/w) of the seed. Seed oil was extracted with n-hexane, yielding 47.2% (w/w). The saponification and iodine values indicated that the oil could be classified among the peanut group of oils. These facts were supported by the detailed fatty acid composition determined by capillary gas chromatography. The ratio of total unsaturated to total saturated fatty acids in the oil was 5.94, with oleic acid being the dominant fatty acid (53.7%). The sterol composition showed higher percentages of b-sitosterol and stigmasterol. The results obtained indicated that, with their attractive properties, G. decorticans is a good candidate for further studies to evaluate their future commercial prospect.

Abstract We present information from 75 nests of Gray-crowned Tyrannulet (Serpophaga griseiceps) found in open Prosopis woodlands of the central Monte desert between 1995 and 1997 and compare it with information corresponding to other species of the genus. Breeding occurred from October to January. Nests are small open cups. Both parents participated in nest building, which lasted 4–7 days. In the Prosopis woodland, 98% of the nests were built in chañar (Geoffroea decorticans), which also is commonly used as a nest plant by S. subcristata in east-central Argentina. Mean clutch size did not vary among years nor within the breeding season, and it was similar to that observed in other Serpophaga. Both male and female shared the 13–15 day incubation period. Hatching was asynchronous. Nestling period lasted 13–14 days, during which both parents reared the chicks. Nesting success (26%) appeared to be less than that previously reported for Nearctic open-nesters (50–60%), and Neotropical open-nesters in dry (50%) and wet tropics (35%). Egg and nestling predation were the main cause of nest failure.

Abstract We present information from 75 nests of Gray-crowned Tyrannulet (Serpophaga griseiceps) found in open Prosopis woodlands of the central Monte desert between 1995 and 1997 and compare it with information corresponding to other species of the genus. Breeding occurred from October to January. Nests are small open cups. Both parents participated in nest building, which lasted 4–7 days. In the Prosopis woodland, 98% of the nests were built in chañar (Geoffroea decorticans), which also is commonly used as a nest plant by S. subcristata in east-central Argentina. Mean clutch size did not vary among years nor within the breeding season, and it was similar to that observed in other Serpophaga. Both male and female shared the 13–15 day incubation period. Hatching was asynchronous. Nestling period lasted 13–14 days, during which both parents reared the chicks. Nesting success (26%) appeared to be less than that previously reported for Nearctic open-nesters (50–60%), and Neotropical open-nesters in dry (50%) and wet tropics (35%). Egg and nestling predation were the main cause of nest failure.

Prenylisoflavanones from Geoffroea decorticans

An assessment of nitrogen fixation capability of leguminous trees in Uruguay

A new species of Pseudorobillarda from a leguminous tree in Argentina

In this paper we describe the activity of a nesting pair of Aplomado Falcons (Falco f. femoralis) during the first days of the nestling period. The nest was found in a Chañar tree (Geoffroea decorticans) at a heíght of 4.5 m in San Luis province. The female remained at the nest 94.14% of the observation time (brooding: 86.90%) and fed the nestlings with a rate of 0.47 items/h. Feeding periods lasted on average 560 sec (Ra: 360-780 sec; n:9). The male was seen on the nest 1.28% of the observation time and brought prey with a frequency of 0.41 items/h. Information of nest and nestling characteristics, territory, defense, caching behavior and vocalizations is also given. Finally we provide a compilation about nesting of the Aplomado Falcon in Argentina.

Halophytic coastal communities in Bahia Blanca, Argentina, were examined in relation to soil salinity along a transect from inland to the sea. The relationships between soil electrical conductivity and dominance-abundance values for different species were determined. The ‘Chanaral’ community with its most conspicuous species Geoffroea decorticans was present in soils with the lowest salinity levels in the area. Halophytic underbush develops at soil salinity values of intermediate soil electrical conductivity, the characteristic species being Cyclolepis genistoides, Atriplex undulata and Salicornia ambigua. Halophytic shrub-like steppe vegetation, dominated by Allenrolfea patagonica or Heterostachys ritteriana, is present in soils with high salinity. It is concluded that the ionic composition of plants was a stable characteristic for different species and did not vary with changes in soil salinity.

A descriptive study of the morphological features of the adaxial and abaxial foliar epidermis of twenty grass species found in the "Sandy grassland area with chañar (Geoffroea decorticans) groves" of San Luis Province, Argentina, is shown in an atlas. This is intended to serve for the microhistological identification of the botanical composition of the diet of both wild and domesticated herbivores. In the area, it has proved effective in dealing with cow, horse, hare, vizcacha, and pampas deer diets.

The morphological and chemical composition and nutritive properties of chanar seed were investigated. The mean pod weight and approximate percentage of pod pericarp, endocarp and seed were determined. Chanar seedlings were inoculated with Rhizobium mesquite and R. tesota and in each case were found to nodulate. The pericarp contained 4.8 percent protein, 1.3 percent fat, 17.2 percent fiber, 2.4 percent ash, 22.7 percent hemicellulose and 48.4 percent sugar, sucrose being the preponderant pericarp sugar. The seeds contained about 29.4 percent protein, 48.9 percent fat, 7.7 percent sugar and 10.5 percent hemicellulose. Linolenic and oleic were the preponderant fatty acids. The seed protein FAO chemical score was 65 with lysine the limiting amino acid followed by methionine + cysteine with a score of 66. Rats fed milled chanar pods lost weight and ate less than the control and had an adjusted PER of —3.97. The diet and nitrogen disgestibility were approximately 67 percent and 1.2 percent, respectively. Low l...

The altitudinal distribution of the vegetation aproximately in the 30 degree of the southern latitude, namely that of the basin of the river Elqui between 100 and 3.000 meters has been analysed.Three different principal altitudinal zones can be recognised: the mountain, the subandine and the andine level. Each zone has characteristic species. The physiognomy is strongly adapted to the environmental conditions of each zone.The mountain level still conserve a number of sclerophyllous evergreen trees representatives tipics from valleys and lowland (Lithraea caustica, Quillaja saponaria and Geoffroea decorticans, Prosopis Chilenis).In the subandine level the trees are the predominent plants occuring in groups and present a number of new exponents (Kageneckia spp., Colliguaya spp. Adesnia spp. etc.).In the andine level scrubs and herbs asociated with grass and perennial gramineus are predominant, forming small patches.It is worth noting at present, the anthropological action zone by the felling of trees, mining, grazing and agricultural effects.