Mariana Lozada

Patterns of use and knowledge of wild edible plants in distinct ecological environments: a case study of a Mapuche community from northwestern Patagonia.

The multiple use of distinct ecological environments in the search for wild resources has been practiced since ancestral times in aboriginal communities inhabiting northwestern Patagonia. This paper examines the actual use and knowledge of wild edible plants in a Mapuche community presently settled in one of the most arid areas of Patagonia, far from the temperate forests where their ancestors used to live. The difference between knowledge of and use of wild plants is analyzed emphasizing that these differences could contribute to the understanding of eroding processes believed to be occurring in the community. These objectives are studied quantitatively by utilizing ethnobotanical indices, partially derived from ecological theory. Our results indicate that the Paineo dwellers still utilize multiple ecological gathering environments and have thorough plant knowledge of both native and exotic species. The Andean forest, more than 50 km away from this community, is the environment from which the Paineo dwellers know the greatest total richness and the highest diversity of wild edible plants, followed by the Monte–Steppe species and lastly, those growing around their homes. The transmission of wild edible plant knowledge in the Paineo community diminishes with age, and the forest plants are the most vulnerable to loss. Our results have shown that the knowledge and consumption of wild edible plants follows a pattern according to ecological conditions of the gathering environments, as well as the cultural heritage of the Paineo people.

Comparison of wild edible plant diversity and foraging strategies in two aboriginal communities of northwestern Patagonia

We have compared edible plant richness, diversity and differential patterns of use in two Mapuche communities of Argentina. The populations of Rams and Cayulef are located in a herbaceous steppe, far from the temperate forests of northwestern Patagonia where their ancestors lived in the past. Ecological concepts and methods, such as diversity indices, niche breadth and optimal foraging theory have been used in this comparative study. Our results indicate that the diversity of wild plants used in Rams and Cayulef is associated with the variety of gathering environments they visit. When comparing diversity indices among the three environments within each community, in Cayulef we found the highest diversity indices for steppe species and the lowest for forest plants. In contrast, in Rams the niche breadth is similar in all environments, indicating an ample exploration and use of edible wild plants. Cost and benefit trade-offs seem to be considered in both communities when edible plants are collected. Nevertheless, we found that the people from Rams not only utilize a greater richness of wild plants than the Cayulef people, but also use more nutritious resources, spend more time traveling to the gathering sites and a longer handling time in preparing these edible plants. This study has quantitatively shown 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.

Edible Wild Plant Use in a Mapuche Community of Northwestern Patagonia

Mapuche Indians have a long tradition of using edible wild resources. The people of Rams (Neuquén, Argentina) consider themselves descendants of the Pehuenches, an Indian group that once inhabited the Pehuén forest region. They now live in the steppe, far away from the forest. Our primary interests are how this community uses edible resources and in analyzing which plants are still utilized. We conducted an ethnobotanical study, which consisted in interviewing several Mapuche families and collecting plants with their help. Ecological variables of plant use, such as search cost, handling time, and nutritional content, were analyzed from the perspective of Optimal Foraging Theory. Our results indicate that the Rams inhabitants have a thorough understanding of their environment, expressed in a selective gathering of wild resources. Cost and benefit trade-offs seem to be considered when edible plants are collected.

Cultural transmission of traditional knowledge in two populations of North-western Patagonia.

BackgroundIn the present study we have investigated the cultural transmission of two types of traditional plant knowledge in two communities of North-western Patagonia, Argentina. In the Pilcaniyeu community, we studied the transmission of traditional knowledge related to horticultural practices in home-gardens, greenhouses and gardens; while in the community of Cuyin Manzano, we studied wild plant gathering customs.MethodsEthnobotanical fieldwork was conducted by means of semi-structured interviews, in which we investigated which plants are used, at what life history phase was learned, modes of transmission and who the principal transmitters were in childhood and adulthood. In both communities, each of this three aspects related to cultural transmission were categorized and the frequencies of each category were obtained. The total number of species recorded in each community was also calculated. Frequencies were analyzed with the Chi-square test of independence.Results and discussionIn both communities, transmission of traditional plant knowledge begins at an early age, as a family custom, in which women play a predominant role. Wild plant use and horticultural knowledge continue to be learned during adulthood. This was particularly registered associated with horticultural learning, which receives greater influence from extension agents who are introducing new practices and technology. This outside influence, which implies novelty, could imply syncretism but also traditional knowledge loss.ConclusionGiven the remarkable acculturation processes occurring at present in rural communities of Northwestern Patagonia, it might be of vital importance to document traditional knowledge of ancient practices. Moreover, it could be interesting to share our results with both populations in order to encourage participatory activities within the communities which could enhance traditional knowledge horizontal transmission, particularly among elder adults and youngsters.

Nontimber Forest Product Use in Two Human Populations from Northwest Patagonia: A Quantitative Approach

The ancestral tradition of gathering nontimber products in the Andean forests of Patagonia seems to be on the verge of disappearing. Edible wild plant knowledge and differential patterns of use have been compared in two populations of different economic and cultural backgrounds—a small rural Mapuche community (Rams), and an outlying population (El Frutillar). The first is located in an herbaceous steppe far from the nearest Andean forest while the second is located outside the town of Bariloche, near the forests of Nahuel Huapi National Park. Semistructured interviews and related ecological variables were compared in both communities. In the past, both communities utilized nontimber forest products from the Andean Temperate forests. However, today, cost and benefit trade-offs appear to affect when and what edible resources are collected. The people from El Frutillar gather fewer wild plants in spite of the high plant abundance and the notorious food scarcity they suffer. The Mapuche people use more nutritious resources, more native species, spend longer traveling to the gathering site, and longer handling time preparing edible plants.

Novel aromatic ring-hydroxylating dioxygenase genes from coastal marine sediments of Patagonia

BackgroundPolycyclic aromatic hydrocarbons (PAHs), widespread pollutants in the marine environment, can produce adverse effects in marine organisms and can be transferred to humans through seafood. Our knowledge of PAH-degrading bacterial populations in the marine environment is still very limited, and mainly originates from studies of cultured bacteria. In this work, genes coding catabolic enzymes from PAH-biodegradation pathways were characterized in coastal sediments of Patagonia with different levels of PAH contamination.ResultsGenes encoding for the catalytic alpha subunit of aromatic ring-hydroxylating dioxygenases (ARHDs) were amplified from intertidal sediment samples using two different primer sets. Products were cloned and screened by restriction fragment length polymorphism analysis. Clones representing each restriction pattern were selected in each library for sequencing. A total of 500 clones were screened in 9 gene libraries, and 193 clones were sequenced. Libraries contained one to five different ARHD gene types, and this number was correlated with the number of PAHs found in the samples above the quantification limit (r = 0.834, p < 0.05). Overall, eight different ARHD gene types were detected in the sediments. In five of them, their deduced amino acid sequences formed deeply rooted branches with previously described ARHD peptide sequences, exhibiting less than 70% identity to them. They contain consensus sequences of the Rieske type [2Fe-2S] cluster binding site, suggesting that these gene fragments encode for ARHDs. On the other hand, three gene types were closely related to previously described ARHDs: archetypical nahAc-like genes, phnAc-like genes as identified in Alcaligenes faecalis AFK2, and phnA1-like genes from marine PAH-degraders from the genus Cycloclasticus.ConclusionThese results show the presence of hitherto unidentified ARHD genes in this sub-Antarctic marine environment exposed to anthropogenic contamination. This information can be used to study the geographical distribution and ecological significance of bacterial populations carrying these genes, and to design molecular assays to monitor the progress and effectiveness of remediation technologies.

Isolation and characterization of biosurfactant-producing Alcanivorax strains: hydrocarbon accession strategies and alkane hydroxylase gene analysis.

Biosurfactant-producing bacteria belonging to the genera Alcanivorax, Cobetia and Halomonas were isolated from marine sediments with a history of hydrocarbon exposure (Aristizábal and Gravina Peninsulas, Argentina). Two Alcanivorax isolates were found to form naturally occurring consortia with strains closely related to Pseudomonas putida and Microbacterium esteraromaticum. Alkane hydroxylase gene analysis in these two Alcanivorax strains resulted in the identification of two novel alkB genes, showing 86% and 60% deduced amino acid sequence identity with those of Alcanivorax sp. A-11-3 and Alcanivorax dieselolei P40, respectively. In addition, a gene homologous to alkB2 from Alcanivorax borkumensis was present in one of the strains. The consortium formed by this strain, Alcanivorax sp. PA2 (98.9% 16S rRNA gene sequence identity with A. borkumensis SK2(T)) and P. putida PA1 was characterized in detail. These strains form cell aggregates when growing as mixed culture, though only PA2 was responsible for biosurfactant activity. During exponential growth phase of PA2, cells showed high hydrophobicity and adherence to hydrocarbon droplets. Biosurfactant production was only detectable at late growth and stationary phases, suggesting that it is not involved in initiating oil degradation and that direct interfacial adhesion is the main hydrocarbon accession mode of PA2. This strain could be useful for biotechnological applications due to its biosurfactant production, catabolic and aggregation properties.

Bioprospection of marine microorganisms: biotechnological applications and methods

Environmental microorganisms constitute an almost inexhaustible reserve of genetic and functional diversity, accumulated during millions of years of adaptive evolution to various selective pressures. In particular, the extent of microbial biodiversity in marine habitats seems to grow larger as new techniques emerge to measure it. This has resulted in novel and more complex approaches for the screening of molecules and activities of biotechnological interest in these environments. In this review, we explore the different partially overlapping biotechnological fields that make use of microorganisms and we describe the different marine habitats that are particularly attractive for bioprospection. In addition, we review the methodological approaches currently used for microbial bioprospection, from the traditional cultivation techniques to state of the art metagenomic approaches, with emphasis in the marine environment.

Aromatic hydrocarbon degradation genes from chronically polluted Subantarctic marine sediments

Aim:  The goal of this study was to identify functional targets to detect polycyclic aromatic hydrocarbon (PAH)‐degrading bacterial populations in cold marine ecosystems.

The importance of location and visual cues during foraging in the German wasp (Vespula germanica F.) (Hymenoptera: Vespidae)

Abstract The way in which foraging wasps use cues for prey location and choice appears to depend on both the context and on the type of prey. Vespula germanica is an opportunistic, generalist prey forager, and individual wasp foragers often return to hunt at sites of previous hunting success. In this paper, we studied which cues are used by this wasp when relocating a food source. Particularly we analysed the response to a displaced visual cue versus a foraging location at which either honey or cat food had been previously presented. We conclude that location is used over a displaced visual cue for directing wasp hovering, although the landing response is directed differently according to bait type. When wasps are exploiting cat food, location also elicits landing, but if they are exploiting honey, a displaced visual cue elicits landing more frequently than location.