Species In Central Chile Research Articles

Positive perceptions and memories of invasive Acacia species in central Chile coupled with high willingness for its control

Positive perceptions and memories of invasive Acacia species in central Chile coupled with high willingness for its control

Species-Specific Responses of Insectivorous Bats to Weather Conditions in Central Chile.

Insectivorous bats play a crucial role in agroecosystems by providing invaluable pest control services. With the escalating impacts of climate change, a comprehensive understanding of the environmental factors influencing bat activity becomes imperative for their conservation in agricultural landscapes. This study investigates the influence of weather conditions, specifically air temperature and relative humidity, on the timing activity and the relative abundance of five insectivorous bat species in central Chile. Data from automatic bat detectors and climatological stations are utilized for analysis. Our results unveil species-specific behaviors, with Tadarida brasiliensis exhibiting early emergence and extended activity periods compared to other bat species. Histiotus montanus and Lasiurus villosissimus display delayed onsets on more humid evenings, whereas Lasiurus varius and T. brasiliensis initiate activity earlier on colder nights compared to warmer ones. Relative humidity emerges as a key factor influencing relative abundance for all species, with more minutes with bat passes detected on drier nights. These findings suggest that global warming may influence observed bat behaviors, potentially altering foraging patterns and activity levels of these bat species. Moreover, as climate change continues, understanding the long-term impact on bat populations and their adaptive strategies is crucial for effective conservation measures. Further studies exploring these dynamics can provide valuable insights for shaping conservation efforts in the face of evolving environmental challenges.

Using Tree Height, Crown Area and Stand-Level Parameters to Estimate Tree Diameter, Volume, and Biomass of Pinus radiata, Eucalyptus globulus and Eucalyptus nitens

Accurate estimates of tree diameter, height, volume, and biomass are important for numerous economic and ecological applications. In this study, we report exponential equations to predict tree DBH (cm), stem volume over bark (VOB, m3), and total above-stump biomass (TASB, kg) using three varying levels of input data for Pinus radiata D. Don, Eucalyptus globulus Labill., and Eucalyptus nitens (H.Deane & Maiden) Maiden planted trees. The three sets of input data included: (1) tree height (HT, m), (2) tree HT and ground projected living crown area (CA, m2), and (3) tree HT, CA, and additional stand parameters. The analysis was performed using a large dataset covering the range of distribution of the species in central Chile and included stands of varying ages and planting densities. The first set of equations using only HT were satisfactory with Adj-R2 values ranging from 0.78 to 0.98 across all species and variables. For all three species, estimation of DBH, VOB, and TASB as a function of HT improved when CA was added as an additional independent variable, increasing Adj-R2 and reducing RMSE. The inclusion of stand variables, such as age and stand density, also resulted in further improvement in model performance. The models reported in this study are a robust alternative for DBH, VOB, and TASB estimations on planted stands across a wide range of ages and densities, when height and CA are known, especially when input data are derived from remote sensing techniques.

Forest type and pH affecting the occurrence and life status of land snails in South American temperate forest

The genus Plectostylus (Stylommatophora: Bothriembryontidae) is found in temperate and Mediterranean ecosystems in central Chile, which are highly fragmented landscapes and vulnerable to human perturbations. However, it is unknown what habitat or environmental variables influence their occurrence and life status. This study analyzed how different habitat and environmental predictors influence the occurrence and life status (alive vs. dead) of Plectostylus chilensis species in central Chile. The snails (or shells) were sampled in different fragments (n = 50). In each fragment, land snails were searched in different microhabitats (e.g., leaf litter or trunks) with different environmental conditions (shady, sunny, humid, dry). At the landscape level, temperature, precipitation, and pH at two levels were incorporated into the analysis. Predictors and responses were analyzed with logistic regression models. Land snail abundance was also analyzed with path analysis. The native forest type (open sclerophyllous scrub) was the only variable that influenced the occurrence of land snails. The life status of P. chilensis was also influenced by forest pH at depths of 0–5 cm, with open sclerophyllous forests, and average top layer pH of 6.1 exhibited higher probabilities of finding alive individuals. The Non-Metrical Multidimensional Scaling associated the land snail abundance with the microsite conditions and the dominant tree species. However, path analysis has not shown significant effects. The smaller privately-owned native forest fragments are key for the occurrence and life status of P. chilensis, although the absence of high-quality microhabitats at any forest patch size could limit their abundance/presence of land snails in time. Facing the ecological and climatic crisis that Chile will experience in the coming decades, the resilience of Chile's terrestrial mollusks will depend on the potential measures of management to protect the remaining native forest patches.

Network-based analysis reveals differences in plant assembly between the native and the invaded ranges

Associated with the introduction of alien species in a new area, interactions with other native species within the recipient community occur, reshaping the original community and resulting in a unique assemblage. Yet, the differences in community assemblage between native and invaded ranges remain unclear. Mediterranean grasslands provide an excellent scenario to study community assembly following transcontinental naturalisation of plant species. Here, we compared the community resemblance of plant communities in Mediterranean grasslands from both the native (Spain) and invaded (Chile) ranges. We used a novel approach, based on network analysis applied to co-occurrence analysis in plant communities, allowing us to study the co-existence of native and alien species in central Chile. This useful methodology is presented as a step forward in invasion ecology studies and conservation strategies. We found that community structure differed between the native and the invaded range, with alien species displaying a higher number of connections and, therefore, acting as keystones to sustain the structure within the invaded community. Alien species acting like keystones within the Chilean grassland communities might exacerbate the threat posed by biological invasions for the native biodiversity assets. Controlling the spread of the alien species identified here as keystones should help managing potential invasion in surrounding areas. Network analyses is a free, easy-to-implement and straightforward visual tool that can be widely used to reveal shifts in native communities and elucidate the role of multiple invaders into communities.

Distribution and ecology of wild lettuces Lactuca serriola L. and Lactuca virosa L. in central Chile

Abstract Wild lettuces (Lactuca L.) provide valuable genetic resources for crop breeding, but are also significant invasive weeds. We explored the distributions, habitats, and ecological characteristics of populations of wild Lactuca species in central Chile. We documented two species – Lactuca serriola L. (prickly lettuce) and Lactuca virosa L. (opium/bitter lettuce) in 204 localities. These observations indicate that: i) both allochthonous (Euroasian) Lactuca species occur and are able to regenerate in central Chile; ii) L. serriola forms dense populations in urbanized areas; iii) both species can expand along transport corridors to high elevations; iv) the spread of L. virosa and persistence of dense populations in elevations above 2,000 m a.s.l. prove the invasiveness of this species in extreme climates; v) both species may contain novel traits of interest for germplasm conservation.

Growth and physiological acclimation to shade in young plants of Adesmia bijuga Phil., a critically endangered species in central Chile

Adesmia bijuga Phil. is an endemic and endangered shrub species of central Chile. Its potential shade intolerance is one of the leading hypotheses for its vigor loss when the species grows beneath closed canopies. The objective of this study was to assess the growth and physiological acclimation to the shade of young plants of A. bijuga. A nursery experiment was established with three light levels based on the interception of photosynthetic active radiation (PAR) (TRT0: control at full sun; TRT60: 60% shaded; TRT90: 90% shaded), and maintained for 71 days during the summer season. Growth and leaf morpho-physiological responses were evaluated at the beginning, at the middle, and at the end of the experiment. The shading treatment increased plant height (H), live crown percentage (Lcrown), and specific leaf area (SLA) compared to the control treatment at full sun. However, light-saturated photosynthetic rate (Amax), dark respiration rate (Rd), and light compensation point (Γi) were higher in TRT60 than in the other treatments, while no differences were found among treatments for the apparent quantum yield (α). At this stage of plant development, our results suggest high acclimation plasticity of A. bijuga to light levels; however, a semi-shade environment (i.e., TRT60) favored a better performance of the species.

Restoring native forests from Pinus radiata plantations: Effects of different harvesting treatments on the performance of planted seedlings of temperate tree species in central Chile

Extensive areas of native vegetation have been cleared to establish commercial exotic tree plantations in south-central Chile, a region known as a world biodiversity hotspot. Despite increasing societal demands to restore native forests in parts of the landscape, documented experiences for this form of restoration are lacking. We conducted a landscape-replicated experiment to test the influence of different harvesting treatments (clearcut, strip-cutting and unharvested control) on the early establishment of native tree species in 20-year-old Pinus radiata plantations. Group plantings of shade-intolerant (Nothofagus dombeyi; Nothofagus obliqua), semi-tolerant (Nothofagus alpina; Laurelia sempervirens) and shade–tolerant species (Aextoxicon punctatum; Cryptocarya alba) were established across the treatments, and seedling performance and water status were monitored during the first two growing seasons. Mean survival was significantly higher in the strip-cuttings (77%) and control (70%) than in the clearcuts (38%), while mean height and root collar diameter growth were significantly higher in the strip-cuttings (16 cm year−1; 0.2 cm year−1) and clearcuts (16 cm year−1; 0.2 cm year−1) than in the control (5 cm year−1; 0.1 cm year−1). Shade-intolerant and semi-tolerant species showed the highest growth responses to openings. Leaf water potential was significantly higher in seedlings in the strip-cuttings than those in the control and clearcuts, and stomatal conductance was significantly higher in the strip-cuttings and clearcuts than in the control. Higher seedling performances and lower water stress in the strip-cutting treatment suggest that partial canopy removal is a suitable method for artificial regeneration of native tree species with different shade tolerances for native forest restoration from P. radiata plantations.

Species-specific effects of the herbaceous layer on recruitment of woody species under different shading and precipitation conditions

Herbs may affect the recruitment of woody species. However, most studies have evaluated the impact of one particular herb species or the herbaceous layer as a whole. It is less known if different herb species have different effects on recruitment of woody species, and whether these effects depend on environmental conditions. In this paper, we evaluated the effects of different native and exotic herb species on recruitment of nine woody species in central Chile, under different conditions of shading and precipitation. The experiment was carried out in an open ruderal area in Santiago, Chile. We conducted a factorial experiment with 360 1 × 1 m pots with monospecific crops of eight herb species and a control without herbs, two levels of irrigation (245 and 534 mm) simulating two precipitation regimes, and the presence or absence of artificial shade simulating a woody canopy. Nine woody species common to the region were sown in each pot. Luminosity (PAR), soil moisture, herb volume, richness of woody species and seedling density of woody species recruited were measured. The effects of herb species on woody species richness varied from neutral in the open condition to mainly negative in the shaded condition. Differences in irrigation did not modify the effects of herbs on species richness. The effects of herb species were more variable when woody species were considered individually. Negative and neutral effects predominated, although some positive effects were observed under shaded and wetter conditions. Our results suggest that different herb species have distinct effects on recruitment of specific woody species and species richness, which mainly depend on shade conditions and secondarily on the precipitation regime, and that herb-woody species interactions are highly specific. Thus, management focused in herb controlling should be species-specific, in terms of herb and woody species, and dependent on climate and woody cover.

Willingness of rural communities to reforest with native tree species in central Chile

Economic development of rural people is not always feasible along with concomitant forest restoration, especially when meager reforestation incentives are oriented to poor rural people who probably are not willing to plant native species in their small plots of land. Forest restoration incentives have been created by the Chilean government to engage poor rural people in reforestation using native tree species to recover degraded lands. Our objective was to compare the willingness of people from rural communities to plant native species if they had to bear the costs or if the government did, and we related the answers to environmental and socioeconomic variables. Of the 217 respondents 53.9% were interested in planting native trees if subsidies became available. Interest decreased if the respondents had to pay for the cost, but only slightly. The willingness to reforest was significantly greater at lower distance from the community to the nearest native forest for those with lower income level, and was higher when there was use of nontimber forest products or wood by the respondents. However, in spite of the positive disposition to plant native trees, only 23% of the respondents were interested in planting on their own land, which is a requirement to receive the economic incentives. Most respondents were willing to plant in open sites and on degraded hillsides that surround their communities. We conclude that despite monetary incentives, benefits cannot reach most rural inhabitants because of their lack of interest in reforesting their own land.

Lioptilodes friasi (Lepidoptera: Pterophoridae) Niche Breadth in the Chilean Mediterranean Matorral Biome: Trophic and Altitudinal Dimensions.

Understanding the factors driving the diet breadth of phytophagous insects remains one of the main questions in ecological research. In this study we explored the diet breadth and plant-insect associations in the plume moth Lioptilodes friasi Vargas & Parra (Lepidoptera: Pterophoridae). This phytophagous insect was originally described in association with a single host species, Haplopappus foliosus (Asteraceae), a native shrub of the Chilean Mediterranean matorral. In order to address the breadth of host plant choice, we surveyed other Haplopappus species growing along the elevation gradient of central Chile from sea level to 2600m. We were able to obtain L. friasi adults from five additional Haplopappus species: Haplopappus chrysantemifolius and Haplopappus decurrens from the coastal zone, Haplopappus multifolius and Haplopappus schumanii from the mid-elevation zone, and Haplopappus scrobiculatus at high elevation. Our results demonstrate that the genus-specialized endophagous herbivore L. friasi has a wider distribution and climatic tolerance than previously described. Its biogeographical range extends from the lowland coastal habitats up to the Andean subnival level. We propose that shared flower phenotypic traits such as morphology and chemical composition may have allowed the colonization of closely related Haplopappus species in central Chile, the expansion of which is limited by the harsh high elevation conditions.

Relationship between climate and geographical variation of local woody species richness within the Mediterranean-type region of Chile

Latitudinal and altitudinal patterns of plant species richness have frequently been related to different climate variables such as precipitation, temperature and evapotranspiration. However, studies assessing this relationship have mostly compared different regions and used regional scales of richness (in quadrants of several km2). It is less known the relationship between climate and geographical patterns of species richness in local scales (richness in < 1 ha plots). For central Chile some studies have described geographical patterns of plant species richness, but only using regional scales to quantify richness. It is not known how local richness of plant species varies geographically and if climate variables are related to this variation. In this paper I evaluated latitudinal and altitudinal trends of local richness of woody species within forest ecosystems of the Mediterranean-type climate region in central Chile, and explored if these patterns are related to climatic variables. We used data collected in the field as well as published data of composition of woody species in plots of 100 m2 collected in different localities within this region. Climatic variables were obtained for each locality from isoclimate curves published for the whole region. Local woody species richness was positively related to latitude and negatively related to elevation. Also, it was positively related to annual precipitation and atmospheric relative moisture, and negatively to mean minimal temperature of winter. In addition, precipitation increased with latitude, and minimal temperature of winter decreased with elevation. These results suggest that climate may be an important driver of altitudinal and latitudinal patterns of local species richness of woody species in central Chile.

Altitudinal and interannual variation in seedling survival of tree species in central Chile: implications for sclerophyllous forest restoration

Un problema en restauracion ecologica de ecosistemas forestales es establecer donde la reforestacion es mas limitada por factores ecologicos, y asi donde son mas necesarios tratamientos adicionales (riego, sombramiento, etc.) dentro del area de distribucion del ecosistema. La densidad, crecimiento poblacional y reproduccion en plantas frecuentemente decrece con la altitud, aunque en regiones semiaridas se observan incrementos iniciales hasta niveles altitudinales intermedios, y luego decrecimientos hacia niveles superiores. Asi, en regiones semiaridas la reforestacion puede ser mas exitosa en niveles altitudinales intermedios de los ecosistemas. En este trabajo se evaluo la hipotesis que en el bosque esclerofilo andino (400 a 1.600 m s.n.m., region semiarida de Chile), la reforestacion es mas exitosa en niveles intermedios de su rango altitudinal. Para esto, fueron plantadas 20 plantas de tres especies arboreas intolerantes que se encuentran en la mayor parte del rango altitudinal del ecosistema (Lithrea caustica, Quillaja saponaria y Schinus polygamus), en cinco sitios a lo largo de un gradiente altitudinal en Chile central (480 – 1.500 m s.n.m.). Este ensayo fue repetido en dos anos consecutivos de diferentes condiciones climaticas (2007 y 2008). La sobrevivencia de plantas de las especies fue superior en altitudes mayores en ambos anos, y la sobrevivencia no difirio entre anos en ningun nivel altitudinal en cada especie. A diferencia de la hipotesis inicial, estos resultados sugieren que la reforestacion del bosque esclerofilo andino puede ser mas exitosa en altitudes mayores de su rango altitudinal, y que en menores altitudes probablemente se requieren tratamientos adicionales (riego o sombra) para reforestacion y restauracion

Nostalgia, the Fleeting, and the Rare in Chilean Relationships to Nature and Nonhuman Species

Semi-structured interviews and participant observation were used to understand how urban Chileans form relationships with nature and nonhuman species in central Chile. Most informants expressed dislike of the typical mediterranean-habitat landscape, characterizing it as dry, poor, and empty. Yet many people expressed nostalgic attachment to specific places, species, and activities that they had experienced, often as children. Most of the reminisced-about interactions were fleeting or had been lost over time. In the dominant discourse, nature in the mediterranean zone of Chile is closely associated with poverty, and it is considered to lack beauty, biodiversity, culture, and history. Appeals to personal nostalgia may break through this discourse to form private assemblages of value. Chileans also attributed social value to interactions with species who are rare or who are found “exclusively” in Chile. Appeals to nostalgia, rarity, and exclusivity help to draw these private discourses into the public realm.

Mesophyll conductance constrains photosynthesis in three common sclerophyllous species in Central Chile

BackgroundQuillaja saponaria Mol., Cryptocarya alba Mol. Looser, and Lithraea caustica Molina Hook et Arn., are common sclerophyllous species in Mediterranean Central Chile. Mesophyll conductance, gm, may strongly limit photosynthesis in these semiarid environments.ResultsSimultaneous measurements of gas exchange and chlorophyll fluorescence were carried out in 45 nursery plants from these species to determine diffusional and biochemical limitations to photosynthesis. Values of stomatal conductance, gs, were greater than those of mesophyll conductance, gm, while their ratio (gm/gs) was not influenced by species being on average 0.47. Relative limitations posed by mesophyll conductance to photosynthesis, Lm, (0.40 ± 0.02) were high compared to those imposed by stomata, Ls (0.07 ± 0.01). The average CO2 concentration in the intercellular air spaces (Ci) was 32 μmol mol−1 lower than in the atmosphere (Ca), while the average CO2 concentration in the chloroplasts (Cc) was 131 μmol mol−1 lower than Ci independent of species. Maximal rates of Rubisco carboxylation, Vcmax, and maximal electron transport rates driving regeneration of RuBP, Jmax, ranged from 13 to 66 μmol CO2 m−2 s−1 and from 33 to 148 μmol electrons m−2 s−1, respectively, and compare well to averages for C3 plants.ConclusionsPhotosynthetic performance was in the series: Q. saponaria > C. alba ≥ L. caustica, which can be attributed first to mesophyll conductance limitations, probably mediated by leaf anatomical traits and then to species specific foliage N partitioning strategies.

Validations of the daily periodicity of increment deposition in rocky intertidal fish otoliths of the south-eastern Pacific Ocean

Daily deposition of otolith increments was validated for juveniles of 8 intertidal fish species in central Chile, Helcogrammoides chilensis, Helcogrammoides ...

Range extension of the non-indigenous alga Mastocarpus sp. along the Southeastern Pacific coast

The red macroalga Mastocarpus sp. (Rhodophyta, Gigartinales) has been reported as a non-indigenous species in central Chile. In this area the geographic range described for the species encompasses approximately 200 km, from Cobquecura (36°08'S, 72°48'W) up to Punta Lavapie (37°08'S, 73°35'W). Observations carried out at 22 localities along the central-southern Chilean coast allow us to extend the known range of this species approximately 300 km to the north and 600 km to the south. Additional analysis indicated high percentage cover on areas described as the introduction point of the species.

Liver ethoxyresorufin-O-deethylase and brain acetylcholinesterase in two freshwater fish species of South America; the effects of seasonal variability on study design for biomonitoring

Responses at low levels of biological organization to evaluate environmental changes and water quality have been used for many years. South America is no different, and recently biochemical endpoints in fish have been used to assess the impacts of industrial and sewage effluents on wild fish populations. For Chilean native freshwater fish, basic biological data is scarce and data on 7-ethoxyresorufin-O-deethylase (EROD) and Acetylcholinesterase (AChE) activity is practically absent. Moreover, extensive variation in these two biochemical endpoints exists among species and seasons. In this article we evaluate seasonal variation in liver EROD and brain AChE activities in Trichomycterus areolatus and Percilia gillissi, two widely distributed native freshwater fish species in central Chile. We observed a marked seasonality in hepatic EROD activity in both species, with maximums for P. gillissi during winter months and sex differences in February, July, August and December. T. areolatus showed no sex differences, and peaks in EROD activity in the middle of summer, winter and late spring. Species differences in EROD activity were observed with activity being 1–2 orders of magnitude higher in P. gillissi compared to T. areolatus. Scarce seasonal variation and no sex related differences in brain AChE for both species were observed. Multivariate analysis (PCA) indicated that physical water quality parameters had some degree of responsibility for the seasonal responses found. The seasonal variability data of these biochemical endpoints were used to optimize study design for future monitoring programs, planning timing of sampling, increasing statistical power by collecting specific sample sizes required.

Characterization of novel microsatellite markers for Eschscholzia californica (Papaveraceae), an invasive species in central Chile

We isolated and characterized microsatellite markers for the California poppy, Eschscholzia californica, which is an invasive species in central Chile. A total of eight polymorphic and six monomorphic loci were developed for the species. Between one and 12 alleles were observed per locus. Polymorphic loci showed heterozygosity ranging from 0 to 0.875 in a sample of 96 individuals obtained from four populations. Only one locus showed significant departures from Hardy-Weinberg equilibrium at all sites. The successful microsatellite amplification makes this set of primers an important tool for understanding the recent and future patterns of invasion and adaptation of E. californica into the new Chilean geographic area. The variation detected is currently being used in a more inclusive study that assesses population expansion in central Chile.

Pollination and breeding system in Adesmia bijuga Phil. (Fabaceae), a critically endangered species in Central Chile

Adesmia bijuga Phil. es una especie arbustiva endemica de Chile central, clasificada como especie en peligro critico. Despues de mas de 100 anos desde su descripcion original por R.A. Philippi (1884), la especie fue redescubierta exclusivamente en dos localidades de la Region del Maule. Una de ellas, en el Fundo San Pedro-Las Canas, se encuentra cercana a la extincion, en un habitat perturbado debido a plantaciones de Pinus radiata. Este estudio examino la biologia de la polinizacion y el sistema reproductivo de A.bijuga, que podrian explicar su restringido numero de plantas. Se estimo la composicion de polinizadores atraidos por las flores y la tasa de visita. Con el objetivo de caracterizar el sistema reproductivo en A. bijuga se realizaron tratamientos manipulativos para cuantificar la capacidad de autofertilizacion, el nivel de aseguramiento reproductivo y la limitacion de polen. Los resultados de este estudio indican que A. bijuga es visitada solamente por polinizadores que pertenecen al orden himenoptera. El ensamble de polinizadores no vario temporalmente durante el periodo de floracion, siendo Bombus dahlbomii el visitador mas frecuente. A. bijuga presento un sistema reproductivo mixto, con polinizacion cruzada y autopolinizacion. El rango de fructificacion vario entre 20% a 60% en ausencia y presencia de polinizadores, respectivamente. Esta capacidad de autopolinizacion podria proveer de aseguramiento reproductivo cuando los polinizadores fallan. Tratamientos con suplemento de polen no incrementaron el exito reproductivo, sugiriendo que la especie no se encuentra limitada de polen. El taxon mostro capacidad de formar semillas asexualmente sin la ocurrencia de fertilizacion (agamospermia). Todos estos factores podrian ayudar a explicar como esta especie es capaz de persistir en el tiempo en una poblacion pequena y aislada. Finalmente, este trabajo discute como los resultados de este estudio pueden ser aplicados en futuras medidas para la conservacion de A. bijuga.