This study investigates how familiarity and initial contact with species can be explained by social-demographic variables in an arid environment of Argentina. Our main objectives were to investigate which species children are familiar with, and analyse the effect of place of residence, sex and age on students' knowledge and initial contact with species. In total, 1746 students between 7 and 18 years old participated in the study, from 25 urban and 19 rural schools. Students were asked to write down ten animals and ten plants, and to indicate where they had seen them for the first time. Children were able to name an important number of species but they were mostly acquainted with exotic ones. Familiarity with species and the use of different sources of information can be explained by interactions between the studied factors, while place of residence was not as significant as we expected. Sex was an important explanatory variable, likely influenced by differences in roles and children activities' preferences. It is necessary to improve the knowledge on native species, particularly those with conservation problems by using information sources close to nature, without neglecting the knowledge of the exotic species that children showed more familiarity from everyday life. Nates, J; Lindemann-Matthies, P (2012). Students' familiarity and initial contact with species in the Monte desert (Mendoza, Argentina). Journal of Arid Environments, 82:98-105. ABSTRACT This study investigates how familiarity and initial contact with species can be explained by social-demographic variables in an arid environment of Argentina. Our main objectives were to investigate which species children are familiar with, and analyse the effect of place of residence, sex and age on students' knowledge and initial contact with species. In total, 1746 students between 7 and 18 years old participated in the study, from 25 urban and 19 rural schools. Students were asked to write down ten animals and ten plants, and to indicate where they had seen them for the first time. Children were able to name an important number of species but they were mostly acquainted with exotic ones. Familiarity with species and the use of different sources of information can be explained by interactions between the studied factors, while place of residence was not as significant as we expected. Sex was an important explanatory variable, likely influenced by differences in roles and children activities' preferences. It is necessary to improve the knowledge on native species, particularly those with conservation problems by using information sources close to nature, without neglecting the knowledge of the exotic species that children showed more familiarity from everyday life.

Abstract. Trichloris crinita (Lag.) Parodi is an important perennial native grass widespread in the range areas of the arid and semi-arid phytogeographical region of Monte, Argentina. Previous studies have shown great variability in forage biomass production per plant among different varieties of this species. The aim of this work was to assess which morphological and physiological traits are associated with differential productivity of T. crinita varieties. Three varieties: Pichi, of high productivity, Arroyito, of medium productivity, and Encon, of low productivity were tested in a field experiment. Dry matter (DM) produced by different organs, assimilates partitioning, and leaf area per plant were measured on three different dates for each variety, during an annual growth cycle, under watered conditions. Relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf area (SLA), leaf weight ratio (LWR) and leaf area development rate (LADR) were calculated at 72, 128 and 172 days after transplanting. Significant differences among varieties were found for DM production of blades, sheaths + culms, panicles, roots and shoot/root ratio. Pichi and Arroyito produced more total plant biomass than Encon and this was associated with higher dry matter accumulation in aboveground organs and larger leaf area. LADR, LAR and one of its components SLA were the parameters that best explained differences in biomass production. DM partitioning to roots (considered as the percentage of total DM) was very high in Encon, the least productive variety. Differences in productivity seem to be directly associated with the mean annual rainfall and inversely associated with the mean annual temperature of the environment where plants were collected. Thus, the growth characteristics of each variety reflect differential adaptation to their areas of origin.Additional keywords: intraspecific variability, partitioning, specific leaf area.

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