Trait variation between and within Andes and coastal mountain ranges in the iconic South American tree Araucaria araucana in Chile

As global commitments to restoration are underway, science is needed to support capacity to achieve meaningful gains for ecosystems and human communities. In Chile, identification and generation of appropriate plant material is a barrier to achieving major restoration goals under the Paris Climate Agreement. Understanding genetic differentiation among plant populations is needed to maximize restoration success. For Araucaria araucana, a highly threatened iconic South American tree, this information is greatly needed to guide restoration and conservation efforts because this species occurs across a strong climate gradient. We grew seedlings from 12 populations of A. araucana across its range in Chile in a common garden to assess regional (coastal versus Andes mountain ranges) and population variation in key plant traits and relate this variation to environmental variables. We demonstrate that A. araucana is differentiated within regions and populations across its range in Chile by a suite of traits, particularly branch number and length (showing plant architectural differences) and needle width (showing leaf investment differences). We show that this variation is at least partly explained by climate and soil variables, with the most variation explained by differences between regions in temperature annual range. Thus, we recommend that restoration efforts focus on conserving genetic variation among and within regions and their populations and preventing the translocations of genotypes between coastal and Andes populations.

Sustainable and efficient protocols for in vitro germination and antioxidants production from seeds of the endangered species Araucaria araucana

Background The Pehuén or Monkey puzzle tree (Araucaria araucana) is an evergreen coniferous tree, which has been historically used for social, medicinal, and nutritional purposes. We have recently showed the value of A. araucana seeds as a rich source of micronutrients and antioxidants. This endemic species present in a reduced area in Argentina and Chile is endangered because of the low germination rate and the overexploitation of its edible seeds. Thus, the massive extraction of its seeds is ecologically non-viable resulting in limited availability of its active metabolites. However, biotechnological approaches are attractive strategies of production of valuable metabolites and healthy specimens of endangered plants. The aim of this work was to develop a protocol for in vitro production of antioxidants derived from A. araucana seeds and to obtain healthy plants by optimized seed germination. Results Calli of Pehuén seeds were induced in Murashige and Skoog medium with different combinations of auxins and cytokinins, in light and dark conditions. Callus from embryonic axes developed in medium with 1 mg/l α-naphthaleneacetic acid and 1.5 mg/l 6-benzylaminopurine in light conditions had efficient biomass production, antioxidant activity, high phenolic, and flavonoid content and no cytotoxicity on mammalian cells. Additionally, 100 % germination was obtained in vitro and healthy plants were acclimatized to non-sterile conditions. Conclusion In conclusion, in vitro culture of A. araucana could provide new and sustainable options for production of its valuable metabolites with possible therapeutic and nutritional uses. Also, optimized plant germination and acclimatization of endangered species can contribute to the preservation of pristine environments.

Altered fire regimes modify lizard communities in globally endangered Araucaria forests of the southern Andes

Wildfire regimes are being altered in ecosystems worldwide. The density of reptiles responds to fires and changes to habitat structure. Some of the most vulnerable ecosystems to human-increased fire frequency are old-growth Araucaria araucana forests of the southern Andes. We investigated the effects of wildfires on the density and richness of a lizard community in these ecosystems, considering fire frequency and elapsed time since last fire. During the 2018/2019 southern summer season, we conducted 71 distance sampling transects to detect lizards in Araucaria forests of Chile in four fire “treatments”: (1) unburned control, (2) long-term recovery, (3) short-term recovery, and (4) burned twice. We detected 713 lizards from 7 species. We found that the density and richness of lizards are impacted by wildfire frequency and time of recovery, mediated by the modification of habitat structure. The lizard community varied from a dominant arboreal species (L. pictus) in unburned and long-recovered stands, to a combination of ground-dwelling species (L. lemniscatus and L. araucaniensis) in areas affected by two fires. Araucaria forests provided key habitat features to forest reptiles after fires, but the persistence of these old-growth forests and associated biodiversity may be threatened given the increase in fire frequency.

Development of an Araucaria araucana Beer-like Beverage: Process and Product

The seed from the Araucaria araucana (in Spanish, piñon) tree, native to Chile and Argentina, is sold mainly as raw seed. Engineering a process to add value to piñon has the potential to positively impact local indigenous communities with very little ecological impact because it is routinely harvested in the wild. This study evaluated the feasibility of using 100% piñon, or as a blend with barley malt, to produce a beer-like beverage, while also evaluating consumer acceptance of the beverage’s piñon characteristics. Prototypes generated based on 93% piñon and 7% oat (enzymatic treatment of α-amylase, glucoamylase, protease and β-glucanase), as well as 50% piñon and 50% barley (no external enzymatic treatment), were evaluated. Overall acceptability by a consumer acceptance panel (21 consumers) rated the 100% piñon and the piñon–barley malt blend 5/9 and 7/9, respectively. The piñon–barley malt blend prototype stood out for its low level of carbohydrates, high potassium content and banana and clove aromas.

Stored water in the inner bark and sapwood: Atypical patterns of daily discharge and recharge, radial osmotic gradient and freezing resistance

Stored water in inner tissues can affect plant water balance and its freezing resistance. We studied the water storages in the inner bark and sapwood of Araucaria araucana, a species with thick inner bark. Specifically, we analyzed its daily behavior, the driving force to radial water movement and its freezing resistance. The whole-stem water content and diameter and sap flow increased in the morning and decreased in the afternoon. An osmotic gradient between stem tissues was involved in the morning water storage recharge. There were no lags in the onset of sap flow between different stem positions, however sap flow at 6m height was higher than basal sap flow in the afternoon, at the time that sapwood water content started to decline followed by the inner bark. Extracellular freezing was delayed down to -6˚C in the inner bark and to -8˚C in the leaves. The unusual diurnal pattern of internal water use may enhance freezing resistance as a consequence of the lower water content and higher osmotic potential when the lowest temperatures occur. The contribution of stem tissues to daily water use and the pattern of ice nucleation observed make this species less susceptible to drought and very low temperatures.