Maytenus Boaria Research Articles

Antioxidant and antimicrobial capacity of Maytenus boaria leaves, recovery by infusion and solvent extraction

BackgroundInfusions of Maiten (Maytenus boaria) leaves are used in folk medicine as an antipyretic and for skin allergic rash treatment. Antioxidant, antipyretic and anti-inflammatory properties of medicinal plants have been attributed to phenolic compounds presence. This work, the first in this type, reports the presence of total phenolic compounds (TPC), total flavonoids (TFC), and the antioxidant activity by DPPH, FRAP and ORAC methods of extracts of maiten leaves, including an infusion; also, antimicrobial activity on Gram + and Gram − bacteria were determined. In addition, the presence of Quercetin and catalase were determined, and the FTIR spectrum was done. ResultsThe best values of TPC and TFC were 20.55 gGAE/kgleaves, and 23.69 gQE/kgleaves, respectively, in an ethanolic extract. Best antioxidant activities were obtained in a methanolic extract for DPPH, aqueous extract for FRAP. No significant differences were observed in ORAC activity determination of aqueous, ethanolic, and methanolic extracts and a maiten infusion, with an average value of 22.41 mmolTE/kgleaves. In the case of antimicrobial activity, extract of maiten leaves can inhibit the growth of bacteria as Escherichia coli and Listeria monocytogenes, among others. ConclusionsM. boaria leaves are an important source of phenolics compounds with antioxidant activity; these properties are observed in extracts and infusions. In addition, the extract of maiten leaves produces the inhibition of pathogens Gram+ and Gram− bacteria, showing the great therapeutic potential of this plant used in folk medicine.How to cite: Soto-Maldonado C, Fernández-Araya B, Saavedra-Sánchez V. Antioxidant and antimicrobial capacity of Maytenus boaria leaves, recovery by infusion and solvent extraction. Electron J Biotechnol 2022;56. https://doi.org/10.1016/j.ejbt.2022.02.002.

Mayten Tree Seed Oil: Nutritional Value Evaluation According to Antioxidant Capacity and Bioactive Properties.

The Mayten tree (Maytenus boaria Mol.), a native plant of Chile that grows under environmentally limiting conditions, was historically harvested to extract an edible oil, and may represent an opportunity to expand current vegetable oil production. Seeds were collected from Mayten trees in north-central Chile, and seed oil was extracted by solvent extraction. The seed oil showed a reddish coloration, with quality parameters similar to those of other vegetable oils. The fatty acid composition revealed high levels of monounsaturated and polyunsaturated fatty acids. Oleic and linoleic acids, which are relevant to the human diet, were well represented in the extracted Mayten tree seed oil. The oil displayed an antioxidant capacity due to the high contents of antioxidant compounds (polyphenols and carotenoids) and may have potential health benefits for diseases associated with oxidative stress.

Leaf litter hides post-dispersed seeds from invasive alien removers in a sclerophyll forest in central Chile

Aim of the study: Seed removal may be a determining filter for regeneration. Factors such as leaf litter, tree cover and seed density affect seed removal. This aims to assess three aspects involving on post dispersal seed removal of four woody species (Lithraea caustica, Maytenus boaria, Quillaja saponaria and Retanilla ephedra) of a sclerophyll forest. Study area: Andean Mediterranean sclerophyll forest of Quillaja saponaria and Lithraea caustica located in the Río de Los Cipreses National Reserve, Chile. Materials and methods: Seven experimental plots were set up, in which seeds were offered in an experiment with variations in leaf litter, tree cover and seed density. Generalized Linear Mixed Models (GLMM) were used for the statistical analysis. Camera traps were installed to identify the seed removers. Main results: Q. saponaria seeds were more removed than the seeds of the other species (0.84, observed mean). Whereas that M. boaria and R. ephedra did not show significant differences on the removal of their seeds (0.77 and 0.67 respectively), both were more removed than L. caustica (0.59). The removal of M. boaria, Q. saponaria and R. ephedra seeds was lower in the presence of leaf litter. No factor influenced the removal of L. caustica seeds. Seed removers were identified as invasive alien species such as Rattus sp. and Oryctolagus cuniculus and native species such as Lycalopex culpaeus. Research highlights: Three woody species of this forest suffer severe seed removal by invasive alien fauna with major implications for the resilience of these forests. The coverage of leaf litter is key to hide away the seeds, increasing survival and could promote germination. Keywords: invasive alien fauna; Mediterranean forest; sclerophyll forest; seed removal factors.

Aspectos reproductivos, arquitectura y fenomorfología de Maytenus boaria Molina (Celastraceae) en Chile central

Maytenus boaria Molina (Celastraceae) is an evergreen native tree which is widely distributed in Chile. It has a high economic potential due to its medicinal value, among others. Despite this, biological information about the species is scarce and often confusing. The objective of the study was to broaden the knowledge about reproductive aspects and the sexual system of M. boaria, along with its modular architecture and pheno-morphology. The study was conducted from August through December of 2016, with adults plants (n=17) selected in urban areas of the Region Metropolitana. A pollination test was performed and the sex of the flowers of each selected tree was identified. In addition, a pheno-morphological diagram of the species was made through the modular interpretation of its architecture and the identification of its phenophases. Results showed that M. boaria is a dioecious and andromonoecious species; it has a low autonomous autogamy and is non-apomictic species that needs pollination vectors for seed production. It has four architectural modules in its crown: dolichoblast of apical bud, dolichoblast of axillary bud, inflorescence and reproductive temporary brachyblasts which are distributed in two architectonic units. The floral biology and pheno-morphology of this species indicate that it would be in an evolutionary process regarding the functionality of hermaphroditic flowers, which has been proposed as an intermediate step from hermaphroditism to dioecy. Further knowledge of these topics will allow for a better understanding of the autoecology of the species in order to have an appropriate and productive management of it.

Reciprocal interactions between a non-native shrub and the dominant native trees of a high mountain woodland: who benefits?

Facilitation by nurse plants is a common interaction, whereby climatic harshness and/or other limiting factors are reduced under the canopy of the “nurse” plant, favoring the regeneration of other plant species. In mountain systems, nurse plant interactions among coexisting native and non-native woody species might reciprocally affect the regeneration patterns of the involved species. Elucidating these relationships might contribute to the understanding of interactions that facilitate the success of non-native woody species at high elevations. We assessed whether the non-native shrub Cotoneaster franchetii and the dominant native trees Polylepis australis and Maytenus boaria, reciprocally affect each other’s regeneration in highland woodlands of central Argentina. We recorded woody recruits (seedlings and saplings) and micro-environmental conditions under the three nurse plants and in gaps without woody cover. The frequency of occurrence of Cotoneaster and Maytenus recruits differed among microhabitats. Polylepis regeneration in the area was almost null. The highest Cotoneaster recruit frequency was under the canopy of conspecifics and Polylepis. Maytenus recruit frequencies did not differ among microhabitats, but saplings had higher frequency under Polylepis than under conspecific nurses. The apparently higher quality of Polylepis as nurse plant might be related to intermediate conditions of photosynthetically active radiation and milder winter temperatures under its canopy. Non-native shrub regeneration seems to be facilitated by one of the native species, whereas neither of the natives seems to be favored by the invader. These results support the importance of biotic interactions as drivers of woody invasion success in mountain ecosystems.

Estructura y regeneración de bosques de Prumnopitys andina en los Andes del sur de Chile

Prumnopitys andina is a conifer tree species with a narrow distribution in Chile and Argentina. Despite its ecological importance, knowledge about the structure and dynamics of the forests where P. andina grows is limited. We aim to describe the structure and regeneration of forest with high presence of P. andina. Forests near Lonquimay (38°1' S, 71.3 W - 38°3'S, 71°3' W) were sampled by measuring trees, regeneration and vascular flora through 24 plots. We found that P. andina predominantly occurs in the upper canopy (15-18 m), usually in company of Nothofagus obliqua and/or Austrocedrus chilensis, in addition to Maytenus boaria and Lomatia hirsuta that occur in the mid-canopy (4-8 m). Based on forest structure, we identified three types of P. andina forests: open, secondary-mature, and pure. Pure P. andina forests reached basal areas among the largest reported for for temperate forests southern South America (230 m2/ha). P. andina regeneration ranged from 1,550 individuals/ha in open forests to 25,000 individuals/ha in pure forests. P. andina exhibited a continuous regeneration strategy, which in the absence of human disturbances, such as grazing by cattle or selective logging, suggests that its populations are self-sustaining.

New record of the endemic jewel beetle Pygicera scripta krahmeri (Coleoptera, Buprestidae, Nacionini) from a coastal forest of Hualpén, Biobío Region, Chile.

Pygicera Kerremans, 1903 is an endemic genus of jewel beetle of Chile distributed in the central Chile hotspot, which is distributed from the Atacama Desert in the north to the Valdivian Forest in the south (Myers et al., 2000). Currently, Pygicera is composed of one species and two subspecies: Pygicera scripta scripta Laporte Gory, 1837 and the Valdivian rainforest subspecies Pygicera scripta krahmeri Moore 1981 (Figs 2-6). The first subspecies is distributed from Limarí in the Coquimbo Region to Curicó in the Maule Region, both in the coast as well as Andean foothills. This is considered the common subspecies (Moore, 1981; Moore Vidal, 2015). The southern subspecies is distributed from Victoria in the Araucanía Region to La Unión in Los Ríos Region (Moore, 1981; Moore Vidal, 2015) and is the rarest and less abundant subspecies. The larvae of both subspecies have been recorded in the "maitén" (Maytenus boaria) Molina, from which they have been reared (Moore, 1981, 1987; Moore Vidal, 2015).

TrypanocidalActivity of Natural Sesquiterpenoids Involves Mitochondrial Dysfunction, ROS Production and Autophagic Phenotype in Trypanosomacruzi.

Chagas disease is a neglected tropical disease that is caused by the protozoan Trypanosoma cruzi and represents a serious health problem, especially in Latin America. The clinical treatment of Chagas disease is based on two nitroderivatives that present severe side effects and important limitations. In folk medicine, natural products, including sesquiterpenoids, have been employed for the treatment of different parasitic diseases. In this study, the trypanocidal activity of compounds isolated from the Chilean plants Drimys winteri, Podanthus mitiqui and Maytenus boaria on three T. cruzi evolutive forms (epimastigote, trypomastigote and amastigote) was evaluated. Total extracts and seven isolated sesquiterpenoids were assayed on trypomastigotes and epimastigotes. Polygodial (Pgd) from D. winteri, total extract from P. mitiqui (PmTE) and the germacrane erioflorin (Efr) from P. mitiqui were the most bioactive substances. Pgd, Efr and PmTE also presented strong effects on intracellular amastigotes and low host toxicity. Many ultrastructural effects of these substances, including reservosome disruption, cytosolic vacuolization, autophagic phenotype and mitochondrial swelling (in the case of Pgd), were observed. Flow cytometric analysis demonstrated a reduction in mitochondrial membrane potential in treated epimastigotes and an increase in ROS production and high plasma membrane permeability after treatment with Pgd. The promising trypanocidal activity of these natural sesquiterpenoids may be a good starting point for the development of alternative treatmentsforChagas disease.

Assessing water use and soil water balance of planted native tree species under strong water limitations in Northern Chile

Some forest plantations with native species are established in semiarid central Chile to compensate for industrial activities such as those of mining. Two of those operational forest plantations were monitored from age 1 to 3 years-old (2014–2016). Some plant attributes and soil volumetric water content (VWC) were monitored for eight native tree species (Acacia caven, Schinus polygamus, Porlieria chilensis, Lithraea caustica, Quillaja saponaria, Cryptocarya alba, Drimys winteri and Maytenus boaria), and a water balance model fitted to assess plant water use. Site preparation comprised planting holes of 40 cm × 40 cm by 50 cm in depth dug with a backhoe. Substrate was removed and mixed with compost in proportion 70:30 before mixing it in the planting hole. Planting holes acted as water reservoirs over the study period with soil VWC generally increasing with soil depth being also less variable deeper than in the upper soil layers. The ratio of adaxial (upper leaf side) to abaxial (lower leaf side) stomatal conductance approximately followed a species gradient from xeric to mesic. Irrigation represented about 26% and 53% of the total water input for the sclerophyll and the D. winteri plantation, respectively. At the plant level (0.4 × 0.4 m), soil evaporation and transpiration of D. winteri (273 and 232 mm year−1, equivalent to 43.7 and 37.1 L plant−1, respectively) were about twofold the values for the sclerophyllous/malacophyllous plantation (138 and 128 mm year−1, 22.1 and 20.5 L plant−1, respectively). We suggest the water budget for the sclerophyll/malacophyllous plantation was tight but feasible to be adjusted while for D. winteri irrigation was excessive, could be drastically reduced, and suppressed altogether if planted in gullies. We believe water balance models and soil moisture content sensors could be used to better plan and manage irrigation frequency and amounts in compensation forest plantations in semiarid central Chile.

New genus and species of Yponomeutidae (Lepidoptera: Yponomeutoidea) associated with Maytenus boaria Molina (Celastraceae) from Chile, with descriptions of immature stages and natural history observations

New genus and species of Yponomeutidae (Lepidoptera: Yponomeutoidea) associated with Maytenus boaria Molina (Celastraceae) from Chile, with descriptions of immature stages and natural history observations

Soil changes associated with land use in volcanic soils of Patagonia developed on dynamic landscapes

This paper aimed to identify indicators of soil degradation in volcanic soils developed in the ecotone between the Andean Forests and the Patagonian steppe. The study area is located in the Percy River Basin, Argentine, on alluvial fans with volcanic soils. Sampling was conducted in two adjacent hillslopes where native forest was replaced by a rangeland with grass-shrub vegetation and a 32-years old Pinus radiata plantation. Sectioned and bulk soil samples were collected along three transects in each land cover up to 40 cm depth. Two forest patches of Maytenus boaria were selected as controls. Physical, chemical and magnetic properties were analyzed. Native forest soils were rich in silt fraction, organic matter and non-crystalline minerals, and presented the lowest values of magnetic susceptibility. Rangeland and plantation soils differed from forest soils in these properties. Soil changes were mainly associated to changes in mineralogy resulting from soil desiccation and to the selective removal of fine particles by erosion, together with differences in the effects of recent volcanic events on the soils. Changes in soils associated with land use affected key properties related to pedogenetic processes. Magnetic susceptibility, organic matter content, texture, and pH NaF were key for understanding soil degradation processes in this dynamic environment.

Desarrollo de especies leñosas nativas y exóticas en cipresales patagónicos.

El crecimiento y la arquitectura de las especies leñosas que habitan los bosques inciden en la dinámica de estas comunidades. El objetivo principal de este estudio fue mejorar la comprensión de la dinámica de los cipresales patagónicos a partir del análisis del crecimiento longitudinal y de la arquitectura de las especies leñosas más abundantes en esas comunidades, las nativas: Aristotelia chilensis, Berberis microphylla, Lomatia hirsuta, Maytenus boaria, Myoschilos oblongum y Schinus patagonicus; y las exóticas: Juniperus communis, Prunus avium, Pseudotsuga menziesii y Rosa rubiginosa. El crecimiento longitudinal del eje principal no se relacionó necesariamente con el aumento en altura de las plantas durante el período de estudio (2012-14). Se registraron decrecimientos en altura en todas las especies excepto en P. menziesii y P. avium, exóticas para Patagonia. La mayoría de los individuos presentaron notables desviaciones de su eje principal de la vertical, las que se correlacionaron negativamente con la longitud del brote distal y con la variación en altura de las plantas. Se agruparon las especies en cuatro grupos funcionales, de acuerdo a su arquitectura y crecimiento. La invasión de los cipresales por parte de especies exóticas como P. menziesii y P. avium, asociadas a grupos funcionales distintos a los de las especies nativas más frecuentes, podría impactar significativamente en la dinámica de esas comunidades promoviendo el reemplazo de las especies nativas por las exóticas dominantes.

NEOTROPICAL TREE PRODUCTION: INSIGHTS INTO GERMINATION, GROWTH AND OUTPLANTING FOR Maytenus boaria

ABSTRACT Knowledge about tree production practices is essential to support forest restoration projects, but is still lacking for many tree species. Maytenus boaria is a neotropical tree distributed across the temperate and subtropical South American mountains. In central Argentina, it is mainly restricted to the most preserved forest remnants. Attempts to plant this species have had little success due to difficulties in seedling production and low seedling survival. We set up four trials aiming to identify the constraints of seedling production and outplanting. Under greenhouse conditions, we evaluated (i) pre-germination treatments and (ii) seedling response to inoculation with arbuscular mycorrhizal fungi (AMF). In the field, we planted M. boaria saplings as well as saplings of the most abundant tree in our study site and recorded (iii) survival and height for 10 years. Finally, (iv) we quantified natural recruitment in an attempt to determine M. boaria regeneration niche. Germination varied from 13.1 to 29.2% among treatments. Depulped seeds stratified at 5 ºC showed the highest germination (29.2%). Shoot phosphorus concentration in AMF-treated seedlings was significantly higher (45%) than in non-inoculated seedlings. Survival of M. boaria saplings was similar to that of the most abundant tree in our study site, but their lower height suggested limited growth. We recorded low abundance of M. boaria seedlings in the field; therefore, we were unable to identify the characteristics of its regeneration niche. Reforestation activities should include seed depulping and stratification at 5 ºC to improve germination. The capacity of AMF to enhance nutrition should be evaluated under field conditions.

A dihydro-β-agarofuran sesquiterpene from Maytenus boaria.

The natural compound (1S,4S,5S,6R,7R,8R,9R,10S)-6-acetoxy-4,9,10-trihydroxy-2,2,5a,9-tetramethyloctahydro-2H-3,9a-methanobenzo[b]oxepin-5-yl furan-3-carboxylate, C22H30O9, (I), is a β-agarofuran sesquiterpene isolated from the seeds of Maytenus boaria as part of a study of the secondary metabolites from Chilean flora. The compound presents a central structure formed by a decalin system esterified with acetate at site 1 and furan-3-carboxylate at site 9. The chirality of the skeleton can be described as 1S,4S,5S,6R,7R,8R,9R,10S, which is consistent with that suggested by NMR studies. Unlike previously reported structures of sesquiterpenes containing a pure dihydro-β-agarofuran skeleton, (I) exhibits a three-dimensional hydrogen-bonded network.

Influence of altitude on local adaptation in upland tree species from central Argentina.

Steep climatic gradients boost morphological and physiological adjustments in plants, with consequences on performance. The three principal woody species of the Sierras Grandes Mountains of central Argentina have marked differences in sapling performance along their altitudinal distribution. We hypothesize that the steep gradient of climatic conditions across the species' altitudinal distribution promotes trait differences between populations of different altitudes that are inherited by the following generation. Seeds from different altitudes were exposed to three temperature regimes to assess differential germination responses. Saplings were then transplanted to a greenhouse to assess possible variations in attributes and performance after 18 months. The three species showed differences in germination responses to temperature among altitudes and/or in sapling attributes and performance. In Maytenus boaria and Escallonia cordobensis, germination success was higher under high temperatures for the highest-altitude, whereas lower temperatures boosted germination of the lowest altitudes. Polylepis australis showed no differences in germination among temperature treatments. In the greenhouse, saplings of the three species from intermediate altitudes showed high performance, whereas the upper and lower populations seemed to be adjusted to tolerating more stressful conditions (i.e., lower temperatures at the upper end and water stress at the lower end), showing lower performance toward both altitudinal limits. These patterns agree with those described for saplings growing under field conditions, suggesting adjustments in response to environmental changes undergone by populations along the altitudinal range. The marked adjustments of populations to the local environment suggest a potentially high impact of climatic change on species distribution.

Heavy metal and trace elements in riparian vegetation and macrophytes associated with lacustrine systems in Northern Patagonia Andean Range.

Vegetation associated with lacustrine systems in Northern Patagonia was studied for heavy metal and trace element contents, regarding their elemental contribution to these aquatic ecosystems. The research focused on native species and exotic vascular plant Salix spp. potential for absorbing heavy metals and trace elements. The native species studied were riparian Amomyrtus luma, Austrocedrus chilensis, Chusquea culeou, Desfontainia fulgens, Escallonia rubra, Gaultheria mucronata, Lomatia hirsuta, Luma apiculata, Maytenus boaria, Myrceugenia exsucca, Nothofagus antarctica, Nothofagus dombeyi, Schinus patagonicus, and Weinmannia trichosperma, and macrophytes Hydrocotyle chamaemorus, Isöetes chubutiana, Galium sp., Myriophyllum quitense, Nitella sp. (algae), Potamogeton linguatus, Ranunculus sp., and Schoenoplectus californicus. Fresh leaves were analyzed as well as leaves decomposing within the aquatic bodies, collected from lakes Futalaufquen and Rivadavia (Los Alerces National Park), and lakes Moreno and Nahuel Huapi (Nahuel Huapi National Park). The elements studied were heavy metals Ag, As, Cd, Hg, and U, major elements Ca, K, and Fe, and trace elements Ba, Br, Co, Cr, Cs, Hf, Na, Rb, Se, Sr, and Zn. Geochemical tracers La and Sm were also determined to evaluate contamination of the biological tissues by geological particulate (sediment, soil, dust) and to implement concentration corrections.

The effect of altitude and grazing on seedling establishment of woody species in central Argentina

Understanding the factors that determine altitudinal distribution of species is very important to evaluate the influence of global change. Although climate is the major driver of vegetation distribution, other factors, such as herbivory by livestock, can be more important locally and regionally. Despite its importance, the altitudinal range distribution of species and how it is influenced by climate and livestock are generally unknown. In the Sierras Grandes Mountains of central Argentina, woodlands of lower and upper altitudes are interrupted by an intermediate vegetation belt devoid of forest. Traditionally, this pattern was assumed to be determined by climate, although recent studies suggest that forest distribution would be driven by livestock grazing. However, the potential altitudinal range distribution of the principal woody species of these forests and how it is affected by livestock are still poorly known. In this study, we used an experimental approach to evaluate seedling survival and growth – with and without livestock presence – of the three principal woody species of the mountain woodlands along the entire altitudinal gradient of Sierras Grandes. In January 2009, we planted seedlings of Polylepis australis, Maytenus boaria and Escallonia cordobensis inside and outside livestock exclosures at seven altitudinal sites established every 200–400masl, from 940masl to 2700masl (i.e., maximum altitude of Sierras Grandes). During the three following winters, we evaluated seedling survival and height and measured stocking rates. Although the three species were able to sprout after browsing, livestock markedly reduced seedling survival and height. Inside the exclosure, the three species successfully survived and grew along the entire gradient, including the altitudinal belt devoid of forest. Furthermore, after three growing seasons P. australis and E. cordobensis flowered inside the exclosure at the altitudes where seedlings reach greater heights (2200masl and 1200 and 1600masl, respectively). We suggest that under the current high stocking rates, livestock would strongly hinder seedling establishment of the three principal woody species at most altitudes of Sierras Grandes. Our findings are in agreement with the assumption that the present altitudinal belt devoid of forest is not climatically driven; rather, livestock is the major factor of current forest distribution.

Is foliar flammability of woody species related to time since fire and herbivory in northwest Patagonia, Argentina?

AbstractQuestionIn northwest Patagonia burning of fire‐resistant forests creates a community‐level positive feedback towards increased fire occurrence because of successional replacement by fire‐prone shrublands. We hypothesize that variability in plant traits related to time since last fire and to herbivory by cattle may affect foliar flammability, thus providing a flammability‐promoting mechanism operating at the level of individual plants. We examine how plant foliar traits affecting flammability vary across species and at sites recovering from recent fires (<15 yr) vs sites not affected by fire for > 50 yr, both in the presence and absence of cattle.LocationNahuel Huapi National Park, northwest Patagonia, Argentina.MethodsWe measured four foliar traits expected to affect flammability: leaf moisture, leaf size, specific leaf area and leaf strength, and conducted tests of ignitability (time to ignition and duration of combustion) on leaves of six common tall shrub and small tree species: non‐palatable Lomatia hirsuta and Diostea juncea, moderately palatable Nothofagus antarctica and Schinus patagonicus and highly palatable Maytenus boaria and Ribes magellanicum. We used ANOVA and PCA to examine potential relationships among species flammability traits, time since fire and presence or absence of cattle.ResultsAt plant level, variability in flammability‐related foliar properties is strongly and consistently related to time since last fire, whereas effects of cattle are more variable across species and treatments. In comparison with unburned forests, the dominant woody species at shrubland sites showed reduced leaf moisture, leaf size and specific leaf area. Under pressure from cattle, N. antarctica, one of the most important woody species in these shrublands, showed changes in some foliar traits expected to enhance flammability (e.g. shorter time to ignition) but overall the influence of cattle on flammability was not consistent.ConclusionsThe current study demonstrates that plant foliar traits vary between recently burned and unburned sites, and that these variations may enhance foliar flammability in shrubland communities.

Landscape Structural Complexity of High‐Mountain Polylepis australis Forests: A New Aspect of Restoration Goals

Forest restoration efforts should aim at creating landscapes with a balanced array of forest stands at varying successional stages, thus providing habitat for a wealth of species and multiple ecosystem services. In most high‐mountain ecosystems of South America, long‐term livestock rearing activities that include fires, browsing, and trampling have delayed or stopped forest succession resulting in simplified landscapes. To determine appropriate restoration goals for Polylepis australis mountain forests of Central Argentina, we established 146 plots of 900 m2 plots throughout five river basins with different historic livestock stocking rates. In each plot, we measured tree heights, canopy cover, estimated age of oldest tree, volume of standing and fallen dead wood, fern cover, and abundance of shade tolerant Maytenus boaria trees. K‐means cluster analysis using tree heights and canopy cover as classificatory variables yielded four biologically meaningful clusters. Clusters 1, 2, 3, and 4 comprising 68, 10, 13, and 9% of the plots, respectively, showed increasing amounts of standing and fallen dead wood, fern cover, and abundance of shade tolerant M. boaria trees. Plots in clusters 1 and 2 were proportionally more abundant in basins with high human impact and at the altitudinal extremes of P. australis distribution, whereas plots in clusters 3 and 4 were relatively more abundant in well‐preserved basins and at the optimum of their altitudinal distribution. We interpret clusters 1, 2, 3, and 4 as degraded, regenerating, young, and mature forests, respectively. Restoration goals should focus on attaining an even distribution of forest types similar to that found in our best‐preserved basins.

Avian gut-passage effects on seed germination of shrubland species in Mediterranean central Chile

Effects of avian gut-passage on seed germination are important to assess the effectiveness of frugivores in woodland regeneration, particularly in biodiversity hotspots that have a high incidence of avian frugivory. We examined the effect of avian gut-passage on seed germination in contrast to seeds that remain uneaten in five shrub species in Mediterranean central Chile and sought to determine the physiological mechanism(s) by which seed germinability is modified. Germination assays were conducted in a glasshouse for five common shrub species of the sub-Andean matorral: Azara dentata (Flacourtiaceae), Schinus polygamus and Schinus molle (Anacardiaceae), Cestrum parqui (Solanaceae), and Maytenus boaria (Celastraceae). We estimated germinability (final percent germination), dormancy length (time from sowing to first germination), mean length of dormancy of all germinated seeds, and contrasted germination rates of defecated versus manually extracted and pulp-enclosed seeds. Avian gut-passage increased seed germinability in four of the five shrub species studied—primarily through deinhibition via pulp removal. Minimum dormancy length was not modified by avian gut-passage for A. dentata, but was significantly shorter for S. molle and C. parqui. Mean dormancy length was significantly shorter in gut-passed seeds of A. dentata, S. molle and M. boaria. Avian gut-passage greatly enhanced the seed germination rates of three species, A. dentata, S. molle and C. parqui. We conclude that the positive effects of birds on seed germination facilitate the regeneration of sub-Andean shrublands, and that bird declines due to landscape change may impair recovery rates of successional or restored areas due to dispersal limitation.