Mendoza Projects
Agustina Novillo CONICET Richness altitudinal gradients in small mammals: I have 4 transects from 32°lat to 35° lat. At each transect I have 5 altitudinal sample points, where I measure small mammal’s species richness. I want to know how richness varies along altitude and correlate this variation with environmental variables (e.g.: temperature, temp seasonality, precipitation, prec. Seasonality). Also I need to account for spatial autocorrelation.
Carmen Sartor I would like to know if there are any differences in the germination response curve of two perennial grasses between open areas and under tree canopies at different rain pulses.
Cecilia Casas My project deal with indirect effect as forces capable of modify the structure and dynamics of the community. Particularly, I was interested in evaluating two previous of relations as structuring forces during the next growing season. The experiment consisted in a factorial arrange of two factors with two levels: Grazing (presence/absence) and Endophyte (infected /non infected). Lolium multiflorum in an annual winter forage grass which is also, naturally infected with Neotyphodium fungi endophyte. Thus, both factors are frequent relations either in natural grasslands and pastures. L. multiflorum seeds infected or non infected with the endophyte were sown in separate microcoms. During the vegetative stage, plant were or not cut twice (six replicates x four treatments). During the next growing season (L. multiflorum cycle has finished), Carduus acanthoides plants were sown in the same microcoms. C. acanthoides as well as L. multiflorum are the main exotic species invade and dominate grassland succession. C. acanthoides biomass, total number of flowers, number of open flowers was measured. The richness and abundance of visitors species was measured during the C acanthoides flowering period. The data analysis should allow me to evaluate if the grazing and the endophyte presence in L. multiflorum are factors capable of affecting the C. acanthoides growth and consequently their visitors.
Eduardo Trumper INTA Agricultural setting: Earwigs as predators of a corn pest. Questions: a)Do earwigs have a preference (adult presence and reproduction) for a particular corn phenological stage? b)Does corn planting date influence earwigs abundance? Does it influence earwigs response to corn phenological stage? Four planting dates. 3 replicates each planting date 15 to 20 sampling dates, depending on plantation (each plantation=a given planting date). 3 sampling units in each experimental unit. Each sampling unit: 10 consecutive plants. At the beginning of the study, there was only one plantation to take samples from. Then a second plantation became available, and so on. At some point in late February, the first plantation reached its physiological maturity and sampling for earwigs stopped in it. Then the second plantation matured and so on. Consequently, only in the middle of the season did we get samples from the whole four planations. Response variables: a) Adults numbers; b) egg masses numbers. Additional question: Does the increase in earwigs abundance through the season identified in each plantation really suggests a preference for more advanced phenological stages, or is it just a consequence of more time available for earwigs immigration into corn plots?
Erica Cuyckens ? Animals killed by routes: Place: route Salta city – Oran (Salta province) (see map) Dates: we travelled the route in dry season (dates: 21/05/2000, 30/05/2000, 2/06/2000, 9/06/2000, 27/06/2000, 29/06/2000, 17/07/2000, 4/08/2000, 15/08/2000, 24/08/2000, 31/08/2000, 4/09/2000, 22/05/2001) and wet season (dates: 9/10/2000, 1/11/2000, 18/11/2000, 7/12/2000, 27/12/2000, 30/12/2000, 29/03/2001, 9/04/2001). We measured at each point: conservation of the forest (good, regular, bad; we have only one animal killed nearby “good” forest), distance to the nearest forest (less than 100, more than 100), human activity (intensive, low; there where no places with animals killed withouth human activity). (see: bichos muertos.xls) Questions: 1. Which species are killed by routes? (boring) 2. How differes the composition of animal species killed between dry and wet season? (only 1 wet and only 1 dry season). 3. How difference the number of animals killed in relation to a. the conservation state of the forest ? (next to the road) b. width of shoulder? c. distance to the nearest forest? (on eather site of the road) d. human activity? Hypotheses: 1.Mammals: wild and domestic, birds that eat dead animals on the route (no or little other birds), reptiles because they lie on the route at night to recover heat, no anfibios or accidently. 2.there will be more reptiles killed during wet season than in dry season. 3.a. Maybe more wild animals killed because we have a source or maybe less because there is no need for them to come out of the forest in search of resources. b. maybe less animals are killed when we have a wide sholder because the animals don’t get close to the road. c. maybe less if the forest is far because the animals don’t get in contact with the road. d. maybe the number of animls killed in places with intensive and low human activity is the same, but maybe they change identity: more domestic animals near places with intensive human activity.
Erica Lujan Stevani CONICET One of the goals of my PhD is to evaluate the effect of fire on the structure of the plant-pollinators-parasite network. I will infer network structure on the basis of trap nests and will assess changes in structure throughout post-fire successional stages. In addition, I will examine those factors that may responsible for network structure. In in this proyect, I want to know if post-fire succession of plant results in a convergence with other sites in the Monte desert that have not suffered fire disturbance recently (within the last 50 years). We worked at 14 sites at Villavicencio reserve, there are 11 sites had suffered fire (in a period of at 1 to 30 years ago), the others 3 sites had not experienced fire (unburnt sites). During the spring of 2008, we set nest traps for wood nesting bees and sampled plant abundance and richness on transects once a week. I would like to know the richness, abundance and identity of plant species in a succession burns sites. This will suggest that fire affects the structure of the plant community.
Federico Cortés ? Environmental effects in the spatial distribution of two shark species in Río de La Plata coastal zone: Rio de la Plata and adjacent marine waters are one of the most dynamics habitats of the Argentine Sea. Rio de la Plata coastal zone (RDPCZ) is used by many shark species as feeding, mating and nursery grounds. Oceanographic processes could differentially affect the habitat use of sharks within RDPCZ, influencing shark availability and fishery impact on it. Therefore, the goal of this study is to determine how the oceanographic factors influence the spatial distributions of two shark species and the similarity of the habitat used by them. The data were obtained from 4 fishery surveys carried out in RDPCZ between 1998 and 2005. In each survey near 80 sampling station was realized. Number of shark caught by specie, spatial data (latitude and longitude) and oceanographic factor (depth, temperature, salinity, bottom type) were recorded in each sampling station. The data challenges is deal with species that shows different patterns of aggregation, overdispersed data, and whit continuous and discrete explanatory variables.
Fernando Biganzoli UBA Baccharis dracunculifolia and Eupatorium buniifolium are both native shrub species having contrasting pattern of population recovery after fire. While most EB individuals resprout after fire, BD individuals died and populations recover by seedling establishment. In order to identify controls of landscape distribution and abundance of these species at El Palmar National Park (Entre Ríos, Argentina), I conduct several censuses in plots of 400m2. In each plot I count all live individuals of Bd and Eb and registered some site descriptors variables (years since last fire, palm densities at the tree layer and sand proportion at soil surface).
Jimena Dorado ? 
I work with solitary bees that nest in wood holes in the Monte desert. I have 3 sites sampled 2 consecutive years. One year was dry and the second was wet, so the floral resources changed between them (I have two more sites that were measured only once in different years each). In each site I put 30 groups of 9 nest-traps and sampled traps and vegetation weekly. From the traps I have the number of cells, the number of adults emerged and the number of parasites for each bee species. I want to see if the abundance of bee population (of the most abundant bee species) is related to resources abundance and also if parasitism rate is also related to bee abundance.
Julieta Aranibar CONICET Data type: Nutrient contents in soils. Project #1:Data: Organica matter, amonium, and nitrate content in soils under -two treatments (wood extraction of 1 ha parcels and control, with 4 repetitions each) -soil sampling was divided in microsites: under tree canopies, exposed areas. Question to answer: Does the treatment (wood removal) affects nutrient content? The preliminary answer is NO, so it may be boring to work with this data, but it is organized in terms of number of samples, and experimental design Project # 2: Data: nitrate concentrations in soil profiles, approximately 20 soil profiles at different landscape units: dunes, valleys, and in between (middle, top, and bottom of the dune). Nitrate content was analyzed at different depths, reflecting (we think) zones of root absorption, and nitrate leaching due to precipitation, and nitrate accumulation . Question to answer: is there a function that represents peaks and throughs that allows us to generalize the root absorption and leaching patterns in the different landscape units?
Julio Edelstein INTA Objectives: Predict abundance levels and temporal dynamics; intra-season and inter-annual/long term interests. Model as management tool, with biological meaning (when possible). ** Data available:** - 4 (or more?) light trap catches of butterflies, with different lengths*, at least 2 spp. - meteorological data. From 3 to more than 20 years depending on locality catches through different "temporal windows", depending on the spp Localities: Manfredi, Rio Cuarto (Córdoba), Paraná (Entre Ríos), Pergamino (Buenos Aires)
Mauro Belleggia Does sex, body size and maturity stage affects the diet of Mustelus schmitti ? The aim of this project is to evaluate the effects of sex, body size and maturity stage in the diet of M. schmitti. I predicted that nest predation is related to (1) body size, (2) maturity stage, or (3) sex. To analyze the data I am planning to fit generalized linear models (GLMs) or generalized additive models (GAMs). 374 specimens were collected from two research cruises in two different areas on the Argentinean continental shelf. A total of 371 stomachs (99.19%) contained food, with 96 taxonomic levels of prey identified. For each prey group (Fish, Crustaceans, Polchaetes and Others), models could be constructed where the number or the weight of each prey group could be used as the response variable, and either shark body size, maturity stage, or sex as explanatory variables.
Natacha Chacoff CONICET I would like to understand how is the relation between the interactions (web size, number of links) along the flowering season and how this relates with the the abundance, richness, diversity and our sampling effort of plants during the season. I have 2 seasons of weekly sampling the data
Natalia Schroeder CONICET “Interaction between guanaco (Lama guanicoe) and livestock in Payunia Reserve (Mendoza, Argentina)” It proposes analyze the influence of livestock and productivity on patterns of distribution and density of guanaco in space and temporal scale. Some research questions are 1. What are the patterns of distribution and density for guanaco in Payunia Reserve? 2. How vary these patterns of distribution and density for guanaco along livestock gradient and variability of system productivity? Hypothesis 1. Guanacos have an “over dispersed” distribution along the landscape with regard to livestock. 2. Density of guanacos is strongly influenced by density of livestock when productivity is lower. Objectives 1. To evaluate the spatial and temporal variation in patterns of distribution and density of guanaco, with regard to livestock presence and density in La Payunia Reserve. 2. To analyze other factors that could influence patterns of distribution and density of guanaco, like productivity. At present, I have one year (four seasons) of raw data about number of individuals and groups of individuals (guanaco and livestock) along 120 km of transects (about 10 km each) following a livestock gradient. I also have data to position every individual and groups in a map field (GPS point, angle to the North, and distance to the observer). I will analyze productivity from spatiotemporal variation of primary productivity, which will be estimated from vegetation indexes (EVI index). I have EVI data in CDs, but I haven’t still processed it.
Nicolás Caruso ? The project goal is to support the conservation of a unique guild of neotropical cats living in a human-modified ecosystem. We aim to understand how four cat species segregate their niches and how habitat alterations caused by men affect cat behaviour and guild structure. Data will be used for contributing to the understanding of the factors affecting these cats' distribution and moderate conflicts with people. I also plan to use the data collected to contribute to the understanding of the factors affecting the distribution of these cats globally and produce a model to predict their occurrence in the region, thus directly contributing to one of the priority projects of the Cat Specialist Group Action Plan. Camera-trapping, radiotelemetry, scat analysis and sign counts will be used to study trophic, spatial, habitat and time niches and their separation/overlap. Through the contact with local communities and educational activities I will favor local community participation and promote the conservation and management of the natural habitats of central Argentina, in particular the Monte and grasslands, which are threatened by the severe alterations caused by extensive cattle breeding and agriculture.
Ramiro guanaco stress physiology as a function of management, age, sex etc.
Sebastián Does nest concealment predict nest predation in forest patches the Mount Lofty Ranges? Is there any differential pattern of nest predation between nests located at the edge or the interior of the forests patches? Does it have to be with the predator type? Nest-site vegetation concealment variables were evaluated as predictors of nest predation in the Mount Lofty Ranges, South Australia. The study was conducted in eight conservation parks (isolated forest patches). Fifteen nest-site vegetation variables were recorded to assess nest concealment, at two habitats forest edge and interior. Nest outcome was assessed after 14 days exposure in 16 transects, across eight parks. Two transects per park where set (one at the edge and one at the interior), each transect containing 10 nests, totalling 160 nests for the study. Within the predictors there were qualitative and quantitative variables. Nest outcome took values 1 or 0 to express predation or survival. Nest predation events were then classified as overall nest predation, predation by birds, predation by mammals, and predation by unknown predators. I expect nest concealment variables to be good predictors of nest predation, particularly by birds (visual orientated predators) and week predictors of predation by mammals (olfactory orientated predators). I also expect nest predation by birds to be more intense at forest edges, and mammals’ predation more prevalent at forest interior. nest predation by birds, mammals, other.
Sergio Piraino So I have tree-ring widths datas, nor physical distribution or numerical datas. Datas are of single chronologies (referred to single trees), mean chronology (site ones) and standardized ones, moreover one PC1. My idea would be to performe a spectral analysis, because I'm interested in finding cycles of growth in my chronologies.
Silvia Lomáscolo CONICET I’m trying to measure the effect of different pollinators of Opuntia sulphurea (Cactaceae) on its fitness. I have data on the per-visit effect of each pollinator species on pollen grain deposition, pollen germination, and seed output as indicators of fitness. I am interested in whether effect on fitness is related to pollinator species, pollinator size, or pollinator abundance.
Silvina Velez CONICET I work in pre and post-dispersal seed predation in a Leguminosae tree, which is a key species in the ecosystem of the Monte Desert. I have data of pre-dispersal seed predation by bruchids beetles and post-dispersal seed predation by ants, small and medium mammals. Additionally, after secondary dispersal by cow endozoocory, I measured the post-dispersal seed predation by ants and rodents that suffer the seeds into the feces of cow. These three issues have basically the same experimental design, station of sampling with enclosures for the different seeds guilds, de same number of seed into each enclosure and the seeds exposed the same time (30 days). My challenge is unify all this results in a model that explain better the functioning of this system, than the results of separates experiments.
Valeria Aschero CONICET Consequences of ungulate herbivores in tree reproduction and seedling establishment
Herbivores may negatively affect plant reproduction and seedling survival of plants. Browsing on tree branches can induce a response and increase spinescence. The potential costs for trees in producing induced responses, as spines, could indirectly affect alocation to reproduction. Trampling on seedlings can diminish survival. Although, the expected negative results of herbivores in reproduction and seedling survival, interaction with herbivores is very important for seedling germiantion and tree establishment in Legume trees. Seed dispersal by herbivores scarifies seed coat and allows its germination, without scarifiaction probability of germination is very low, so herbivores may increase seed germination. Using data of Prosopis trees We would like to ask: 1.How does spine length is related to fruit production? 2.How does germination changes with herbivores density? 3. How does seedling survival changes with herbivores density? We have data of 30 Prosopis flexuosa trees on spine length and fruit production, half of the trees were inside Ñacuñán Reserve. This reserve has a perimetral fence and had excluded ungulate herbivores for 37 years. The other half of the trees are in the cattle ranches sorrounding the reserve. In order to answer the last questions I have indirectly measured herbivore presure with cattle dung density at 5 ¼ plots inside and outside the reserve. (This means that for the last 2 questions I have only 6 independent points, snif!).Seedling germination and survival was estimated inside the paired plots. Seedling were counted and tagged at the beginning of the germination period (february-march) and its survival was checked after aproximately 3 months.
Valdemar land snail growth curves: I work in population dynamics of the land snail Plagiodontes patagonicus. This is one data-set. I have growth data on shell lengths obtained from a mark-recapture study on a natural population. I am interested in estimating mean growth over the entire study period, and in describing how relative growth rate changes with snail size. The problem is that recapture rate is low. There is no such thing as complete records for a snail, with observations for all sampling dates. Quite the contrary, many snails were recaptured only once, and there are many different recapture histories.
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