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In this paper we summarize for the first time the effects of agriculture expansion and intensification on animal diversity in the Pampas of Argentina and discuss research needs for biodiversity conservation in the area. The Pampas experienced little human intervention until the last decades of the 19th century. Agriculture expanded quickly during the 20th century, transforming grasslands into cropland and pasture lands and converting the landscape into a mosaic of natural fragments, agricultural fields, and linear habitats. In the 1980s, agriculture intensification and replacement of cattle grazing-cropping systems by continuous cropping promoted a renewed homogenisation of the most productive areas. Birds and carnivores were more strongly affected than rodents and insects, but responses varied within groups: (a) the geographic ranges and/or abundances of many native species were reduced, including those of carnivores, herbivores, and specialist species (grassland-adapted birds and rodents, and probably specialized pollinators), sometimes leading to regional extinction (birds and large carnivores), (b) other native species were unaffected (birds) or benefited (bird, rodent and possibly generalist pollinator and crop-associated insect species), (c) novel species were introduced, thus increasing species richness of most groups (26% of non-rodent mammals, 11.1% of rodents, 6.2% of birds, 0.8% of pollinators). Much taxonomic and ecological work is still needed to understand Pampean animal biodiversity, to understand how agriculturization is affecting it, and to identify appropriate conservation actions. Networks of Important Bird Areas and Valuable Grassland Areas harbor a balanced representation of Pampean biodiversity and, if adequately protected, may provide valuable research sites, but complementary work should be carried out on agriculturized areas. [ABSTRACT FROM AUTHOR]

In this paper, we analyzed the taxonomic diversity of the Argentine dicots to evaluate their relationships with area, latitude, and longitude. We also evaluated species diversity and higher taxa diversity relationships. The families, genera and species diversity in Argentine dicots was not explained by the area of each province but it varied through latitudinal and longitudinal gradients. The taxonomic diversity of these plants increased from high to low latitudes and west-east longitudes. These patterns would explain why the main diversity centers are located in the North region of this country. As we expected the species diversity and higher taxa diversity showed a positive relationship. At this scale, higher taxa diversity could be use as surrogate for species diversity. [ABSTRACT FROM AUTHOR]

We often wonder how many of the pristine places left on Earth we can protect from deterioration before it is too late. The assumption that remote regions remain pristine plays a key role in directing policies for regional environmental management and conservation, and affects the local and global financial impetus to do so. In this paper, we use Argentinean Patagonia and the SW Atlantic as examples to argue that the assumption 'remote region = pristine region' is unjustified and based on a lack of information rather than on scientific evidence. We also discuss the major existing environmental threats to this supposedly 'pristine' region, and use emblematic examples to provide a more realistic picture of the regional environmental integrity and to set recommendations directed to improve environmental management and conservation within this context. [ABSTRACT FROM AUTHOR]

The Chaco and Pampean provinces in the Neotropical region are highly disturbed by intensive forestry and livestock raising. This study is an integrative approach that aims to identify areas to be protected in these provinces. The distribution of 57 phytophagous coleoptera species was used, with a dataset comprising about 1500 georeferenced records. This information was used to analyze species richness and endemicity, build species distributional models projected to the Mid-Holocene, and perform a spatial conservation prioritization analysis of the landscape. Areas with high species richness, endemism areas, refugia (areas where the climate has remained favorable for most of the study species since the Mid-Holocene), and areas with a high conservation value of the landscape were recovered. Finally, all the evidence was considered together, and regions were recognized where the areas recovered following the previous four approaches were congruent. These areas are currently only partially protected and are regions where human activities pose a threat to biodiversity. All the evidence indicates that these are unique regions with features that make them particularly worthy of conservation. Integrating different approaches provides valuable information for recognizing areas that should be prioritized for biodiversity conservation. [ABSTRACT FROM AUTHOR]

Located along the Argentine coastline of northern Patagonia, are San Matías (SMG) and San José (SJG) gulfs; although they are regarded as an area with a high-priority conservational status, knowledge on their diversity is currently fragmentary. Studies on molluscs from this area have been historically centred in economic resources and few works have referred to non-commercial species. The present study aims to document the biological diversity of molluscs at the SMG/SJG area, in order to determine the significance of these two gulfs in the context of the Argentine marine fauna; to evaluate how well represented is this fauna in three protected areas; and to compare the fauna present in the protected areas with that of a non-protected area. For that purpose, molluscs coming from 132 sampling stations, ranging from the intertidal to 170 m depth, were studied, and a thorough bibliographic compilation was performed. A total of 196 species of molluscs are reported for the area. Surprisingly, almost one third of these species lacked previous records for SMG/SJG, including several new/possibly new species. The three studied protected areas contain 88.3% of the species recognised for the entire SMG/SJG area. Although several species appear as exclusive from one of these three areas, many of them are also present in an intermediately located, non-protected area. Molluscan diversity at the SMG/SJG area is greater than previously thought, comprising about 41.4% of the bivalves and 37.8% of the gastropods present in the Argentine shelf; thus suggesting that the area may be considered as a hot-spot of diversity in the Argentine Sea. [ABSTRACT FROM AUTHOR]

Connectivity losses lead to a reduction of the amount of habitat resources that can be reached and used by species, and hence to a decline in the ranges and abundance of multiple taxa. Despite the recognized important role of small habitat patches for many species inhabiting fragmented landscapes, their potential contribution as stepping stones for maintaining overall landscape connectivity has received less attention. Using connectivity metrics based on a graph-theoretic approach we (i) quantified the connectivity of grassland patches in a sector of the Pampa region in Argentina, using a range of dispersal distances (from 100 to 10,000 m) representative of the scale of dispersal of different species; (ii) identified the most relevant patches for maintaining overall connectivity; and (iii) studied the importance of small patches (defined for different area thresholds of 5, 20, and 50 ha) as connectivity providers in the landscape. Although grassland patches were in general poorly connected at all distances, some of them were critical for overall connectivity and were found to play different crucial roles in the patch network. The location of small patches in the grassland network allowed them to function as stepping stones, yielding significant connectivity gains for species that move large distances (>5000 m) for the three area thresholds considered. Thus, under the spatial pattern of the studied landscape, species that move long distances would benefit from stepping stones, while less mobile organisms would benefit from, and mostly rely on the largest patches. We recommend that future management activities should (i) aim at preserving the grassland patches with the highest potential as stepping stones to promote landscape-level connectivity; and (ii) pay more attention to the conservation of key small patches, particularly given that usually they are those more vulnerable to land clearing for agriculture. [ABSTRACT FROM AUTHOR]

The extent to which small shifts among local topographic microsites could mitigate the effects of larger-scale climate change in arctic-alpine systems including mountain top organisms is largely unknown. This study is among the first to evaluate the relative contribution of microsite and altitude as a proxy for climate change on saxicolous lichen communities. We registered 107 lichen species in 54 boulders ranging from 900 to 2700 m.a.s.l. and in a large array of microsites in central Argentina. Communities ordinated along NMS multivariate analysis axes 1, 2 and 3 presented a cumulative R of 80%. The three axes were explained by altitude with axis 1 only being explained by altitude. Axis 2 was also explained by slope and aspect whereas axis 3 was explained by the interaction of altitude with aspect indicating that aspect was important only at lower altitudes but not at the mountain top. Lichen cover and richness were similar throughout the altitudinal gradient. We interpret that under a climate warming scenario, lower altitude species occupying pole ward facing slopes will have to migrate upwards while at the mountain top-for most communities-there still is scope for microsite segregation to compensate climate change. [ABSTRACT FROM AUTHOR]

In a Mapuche community situated in the sub-antarctic forest of the northwest of Argentine Patagonia, analysis was carried out on forest environmental perception and its relation to the resilience of the body of traditional botanical knowledge regarding medicinal plants. Data was obtained on the ethno-classification and differential use of the forest gathering environment with respect to its practical and cultural value. Semi-structured interviews were carried out with 30 randomly chosen inhabitants, and the data were analysed using qualitative methods and non-parametric statistics. Most citations (64.5%) were of species gathered in Nothofagus antarctica forest, 26.2% were of species from N. pumilio forest, and 20.3% referred to species from a mixed forest, with N. dombeyi. The forests studied have low values for similarity in terms of medicinal species richness, indicating a unique offer of therapeutic resources in each one. The use of the different forest types seems to be associated with the search for therapeutic resources for specific ailments. However, the redundancy of functions of species in each forest type can offer alternative remedies, which provides plant conservation, security and the possibility of reorganisation of their traditional medicinal knowledge. This case study showed the importance of considering folk systems and the role that this knowledge has played in plant resource management and forest protection. Different forests are used and valued differentially, not only with regard to usefulness but also in symbolic-religious terms, and together they fulfil a cushioning function, protecting holistically traditional botanical knowledge, people's health and forests. It is of great importance, therefore, that conservation policies favouring environmental heterogeneity are implemented, and that local inhabitants participate in the development of management plans. [ABSTRACT FROM AUTHOR]

The present study focuses on the geographic distribution and biodiversity of the Chlorococcales in Patagonian lakes, covering a latitudinal transect. Two different approaches are considered (a) a review of the historical records of Chlorococcales in Patagonia and (b) the analysis of the morphology-based species diversity, ecological remarks, and geographic distribution of the chlorococcalean species recorded in 33 aquatic environments during surveys 2007 and 2008. A total of 308 chlorococcalean species were recorded throughout a 60-year period in Patagonian freshwater systems, encountering the highest chlorococcalean richness in lakes and shallow lakes located in the more intensively sampled areas. In our surveys 2007-2008, 72 chlorococcalean taxa were registered, among which 80% are worldwide distributed, about 19% are restricted to cold temperate areas in both hemispheres and one species ( Pediastrum patagonicum) is one of the taxa probably endemic for Patagonia. The chlorococcalean richness in relation to the environmental factors, revealed that it is directly correlated with the trophic status of the water bodies (chl a: r = 0.52 and DIN: r = 0.47; P < 0.05). The latitude was inversely correlated with the species richness ( r = −0.40; P < 0.05), and the chlorococcalean biodiversity of the Andean lakes (mean value: 3.64) was significantly lower ( P = 0.0022) than that of the lakes from the Patagonian Plateau (mean value: 9.62). In this study we observed a decreasing trend in the biodiversity of Chlorococcales with increasing latitude, which fits in the existing ecological pattern described for different groups of organisms. [ABSTRACT FROM AUTHOR]

For more than a century, two major zoogeographic provinces have been proposed for the southwestern Atlantic: a warm water Argentinean Province from Rio de Janeiro (23°S, Brazil) to Valdés Peninsula (42°S, Argentina), and a cold water Magellanic Province from Valdés Peninsula to Cape Horn. This zoogeographic scheme has been recognized so far using data covering only parts of the whole geographic area. Here, we test the validity of this scheme by analyzing the distribution of sharks, skates, rays and chimaeras, using data from research cruises covering the entire area. We used cluster, similarity and dissimilarity analyses to identify species assemblages, and canonical correspondence analysis to identify the main environmental variables affecting the composition of the assemblages. The distribution of chondrichthyan assemblages strongly supports the current zoogeographic scheme and identifies a previously unknown and distinctive deep water zoogeographic unit off southern Brazil. Both, the Argentinean and Magellanic Provinces had extensive internal structure, with four and three subareas identified in each of them, respectively. These subareas correspond, with slight differences, to previously proposed zoogeographical districts within the Argentinean Province and confirm ecological differences within the Magellanic Province. Species composition had the highest correlation with depth and bottom water temperature. Since the distribution of anthropogenic disturbances in the region is uneven, different assemblages can be subjected to different impacts. Our results provide an objective basis to establish priority areas for the conservation of chondrichthyans in the southwestern Atlantic. [ABSTRACT FROM AUTHOR]

Anthropogenic habitat disturbance can have profound effects on multiple components of forest biotas including pollinator assemblages. We assessed the effect of small-scale disturbance on local richness, abundance, diversity and evenness of insect pollinator fauna; and how habitat disturbance affected species turnover across the landscape and overall diversity along a precipitation gradient in NW Patagonia (Argentina). We evaluated the effect of disturbance on overall pollinator fauna and then separately for bees (i.e. Apoidea) and non-bee pollinators. Locally, disturbed habitats had significantly higher pollinator species richness and abundances than undisturbed habitats for the whole pollinator assemblage, but not for bees or non-bees separately. However, significant differences in species richness between habitats vanished after accounting for differences in abundance between habitat types. At a local scale Shannon-Weaver diversity and evenness did not vary with disturbance. A β diversity index indicated that, across forest types, species turnover was lower between disturbed habitats than between undisturbed habitats. In addition, rarefaction curves showed that disturbed habitats as a whole accumulated fewer species than undisturbed habitats at equivalent sample sizes. We concluded that small patches of disturbed habitat have a negligible effect on local pollinator diversity; however, habitat disturbance reduced β diversity through a homogenization of the pollinator fauna (in particular of bees) across the landscape. [ABSTRACT FROM AUTHOR]

Until the beginning of the twentieth century there were extensive subtropical seasonal thorny forests surrounding the Pampas grasslands of Argentina, known as the 'Espinal'. In central Argentina there still exist relicts of the Espinal, belonging to the 'Entrerrianense District'. These forests were never described or analyzed in detail. In 2004 we studied 10 randomly located plots of 50 9 2 m. All individuals and stems of woody species were counted and their diameters at breast height (DBH) were measured; individuals with\1 cm DBH were considered juveniles. We recorded 2,300 woody individuals/ ha corresponding to 12 species. The more constant species are the palm Trithrinax campestris (100%), Celtis tala (90%), Prosopis alba and Celtis pallida (both 50%). The plots are relatively homogeneous, but once classified with cluster analysis two groups are formed according to the relative abundance of C. tala and T. campestris; the latter species is more frequent in more open or fire-disturbed habitats. The results of Canonical Analysis of Principal coordinates are in agreement with the classification. We postulate that the differences between both groups are caused by a differential degree of disturbance (probably caused by fires). Both dominant species show abundant juveniles, and the invasion by exotic woody species is limited. These forest relicts are among the last remnants of the massive expansions of forests in central Argentina. Besides their historical value, an urgent call is made for their preservation, sustainable use and defence from biological invasions. [ABSTRACT FROM AUTHOR]

Longitudinal distribution and abundance of macroinvertebrate communities were examined in relation to hydrochemical variables along the Chubut River in the Patagonian Precordillera and Plateau, Argentina. The Chubut River (> 1000 km) is the largest river in the area and its basin is subject to multiple uses: agriculture, cattle raising, urbanization and the hydrological regime of the lower section is modified by a reservoir. Quantitative benthic samples were collected at 13 sites in the higher, middle and lower sections of the river basin. Sites were visited four times during 2004 and physicochemical parameters, chlorophyll a and particulate organic matter (POM) were assessed. Ninety-five taxa were collected in the study, with total species richness per site ranging from 5 to 51, and benthos density averaging 299-5024 ind m-2. Altitude and turbidity were implicated as important factors determining macroinvertebrate assemblages along the river system, and an eutrophication gradient was documented in the regulated/urbanized section of the main river. High turbidity (TSS) and sedimentation limited algal productivity in the middle basin. Below the dam, TSS, total phosphorus (TP) and POM decreased, whereas soluble reactive phosphorus (SRP) and chlorophyll a increased. Macroinvertebrate density increased three fold in this area possibly due to habitat improvement and enhanced trophic resources. Mean species richness did not change below the impoundment; however the community was dominated by gastropods, chironomids and flatworms. The Chubut River is complex and its biotic community reflects the landscape attributes. While benthic composition and density was governed by turbidity and flood disturbance in some river segments, a greater environmental heterogeneity resulted in an unexpected high number of species at the main channel upper basin. [ABSTRACT FROM AUTHOR]

The UNESCO Man and the Biosphere Program (MAB) proposes an interdisciplinary research agenda and capacity building aiming to improve the relationship of people with their environment globally. The aim of this note is to analyze the problems detected during the process of implementation of the biosphere reserve concept in a highly developed region in a developing country, taking as example the Parque Atlántico Mar Chiquito Biosphere Reserve from Argentina. Two big questions emerge from this analysis: who empowers the local stakeholders in a context of private properties with high prices of commodities?, and how can scientific results related with the environmental sustainable develop be put in a practical context without appropriate institutions? [ABSTRACT FROM AUTHOR]

We have compared the species richness of medicinal plants and the differential patterns of use amongst settlements in the Andean communities of Northwest Argentina which have differing levels of isolation. About 259 ethnoespecies, belonging to 74 plant families, were included, representing between 70 and 80% of the total estimate. The results indicate that Coronopus didymus is the most relevant and important species. The method of use of medicinal plants and the ailments treated by rural doctors compared to those of the layperson is different. Native and exotic plants are used differently according to the body system treated. There are some relationships between internal and external use and body systems and recipes. The greater medicinal species richness found in the less isolated locations is due to external enriching cultural influences. [ABSTRACT FROM AUTHOR]

Medicinal plant extraction is a relevant issue in the province of Córdoba, Argentina. A quantitative methodology is proposed for the evaluation of conservation priorities for species used in popular medicine in the Paravachasca Valley, Córdoba. Qualitative attributes were surveyed through the knowledge and perception of local communities. Species are ranked by their index of conservation priority (ICP) values. This index takes into consideration the following data: harvest, abundance, propagation method, origin and commercial demand of species in the area. Among the native species prioritized for conservation are Minthostachys mollis, Hedeoma multi.ora, Julocroton argenteus, Baccharis crispa, Trixis divaricata subsp. discolor, Passiflora caerulea, Usnea spp. and Equisetum giganteum. [ABSTRACT FROM AUTHOR]

We use sample-based rarefaction curves to evaluate the efficiency of a rapid species richness assay of ground beetles and ants captured in pitfall traps in the Nahuel Huapi National Park (NW Patagonia, Argentina). We ask whether ant species richness patterns show some concordance with those of beetles, and use several extrapolation indices for estimating the expected number of species at a regional scale. A total of 342 pitfall traps were spread in groups, at an intensity of 9 traps/100 m², with two collection stations, at each of 19 sites representative of burned and unburned habitats in the forest, scrub and steppe, along a west-to-east transect of 63 km long. The high regional habitat heterogeneity along the west-to-east gradient is paralleled by a turnover of beetle and ant species, although different families of Coleoptera show idiosyncratic responses across habitat types. Spatial stratification of sampling over three major habitats along with the inclusion of burned and unburned environments may improve sampling efficiency. The observed and extrapolated species richness suggests that we captured a high proportion of the total number of species of beetles and ants known for the region. However, trends in species richness of ants may not indicate similar trends in beetles. Ants and beetles cannot be used as surrogate taxa for the analysis of species richness patterns. Instead, both taxa should be considered as focal as they may offer complementary information for the analysis of the effect of disturbance and regional habitat heterogeneity on species diversity patterns at a regional scale. [ABSTRACT FROM AUTHOR]

We investigated habitat variables influencing the species richness and composition of anuran tadpole assemblages in ponds from riparian areas of the Middle Paraná River. Tadpoles were collected at seven ponds that differed in hydroperiod and 10 habitat variables (water temperature, pH, conductivity, dissolved oxygen, turbidity, depth, size, time of isolation, macrophyte richness, and level of natural or anthropic disturbances) during a 5 year period. The presence/absence of potential tadpole predators was also recorded. Although we did not examine tadpole diets, we categorized anurans into ecomorphological guilds. We found that dissolved oxygen, maximum depth, pond size, macrophyte richness, and disturbances were significantly related to tadpole species richness. We also found that the richness of potential tadpole predator increased with longer pond hydroperiod. Thus, the number of tadpole species was higher in temporary and semi-permanent ponds without potential tadpole predators. The results of our study provide the first quantitative data on the tadpole assemblages in ponds associated with riparian areas of the Middle Paraná River Floodplain based on multi-year intensive sampling, a finding of both ecological interest and practical significance for future conservation management of anurans of Paraná River ecosystems. [ABSTRACT FROM AUTHOR]

The tropical–temperate interface of the southern Neotropics harbours an interdigitating array of biomes (Puna, Monte, Chaco, Yungas). This topographic and climatically complex region needs urgent conservation efforts, as it is being transformed by human activities at an accelerating pace. We analyse georeferenced field records of mammal species in northwestern Argentina (provinces: Catamarca, Jujuy, Salta, Tucuman) in order to define biodiversity hotspots on the basis of 0.5°× 0.5° grid cells within northwestern Argentina according to total richness of mammal species, richness of megaspecies (species above 10 kg), and endemic species (species restricted to Argentina or neighbouring countries with shared biomes). The mammal fauna of northwestern Argentina is fairly well known (176 species). The biomes differ considerably in species richness (Puna low, Yungas high) and species composition. We found no significant difference between endemic and non-endemic species regarding cell occupancy or body size. Cell occupancy was not correlated to body size. Across grids, species richness, number of megaspecies as well as richness of endemics are all correlated to sampling effort. More than 50% of the species in the region are restricted to one or two biomes. Overall, the species turn-over between biomes in northwestern Argentina is high. Using a simple algorithm we identified 10 grid cells which covered 90% of the total number of recorded species, and contrast them with the protected areas. While the Puna and Yungas biomes are rather well protected, the arid and semiarid Monte and Chaco are in need of urgent attention in biodiversity conservation. [ABSTRACT FROM AUTHOR]

Compares edible plant richness, diversity and differential patterns of use in two Mapuche communities of Argentina. Details of study using diversity indices, niche breadth and optimal foraging theory; Results indicating that the diversity of wild plants used in Rams and Cayulef is associated with the variety of gathering environments they visit; Comparison of diversity indices among the three environments within each community; Data indicating that the restricted access to Pehuen forest (Araucaria araucana) is the main factor which seems to limit wild plant diversity used in these Mapuche communities.

Presents a study to evaluate the effects of grazing disturbance on insect communities at a montane grassland in Central Argentina. Comparison of two grazed sites differing in cattle load; Consideration of taxonomic and guild structure as important aspects of insect diversity; Measurement of abundance, richness, diversity and biomass of the insect assemblages; Findings that family taxonomic level could be as or even more appropriate than species level in order to characterize insect communities.