A framework for the classification Chilean terrestrial ecosystems as a tool for achieving global conservation targets
Martínez-Tilleria, K., Núñez-Ávila, M., León, C., Pliscoff, P., Squeo, F., & Armesto, J.
Countries that are signatories of the Convention of Biological Diversity are committed to the goal of protecting 17% of their natural ecosystems by 2020. The lack of an up-to-date, operational classification and cartography of regional ecosystems seriously limits the assessment of progress towards this goal. Here, we present a broad ecosystem framework, which combines land use, functional traits of dominant plant species, and climatic factors for the classification of terrestrial ecosystems and apply this framework to classify Chilean terrestrial ecosystems. This new classification is consistent with the recently proposed IUCN framework to assess ecosystem conservation status. Using this framework, we identified and described 30 Chilean terrestrial ecosystems, including land units of natural and anthropogenic origin. We also provide a cartographic representation of ecosystems for land planning purposes and an overall assessment of their conservation status. We evaluated the representation of the 30 ecosystems in the Chilean National System of Protected Areas (NSPA) and in Private Protected Areas (PPA), identifying 15 ecosystems underrepresented (below the 17% target) in the NSPA, in contrast to only 11 when the area of NSPA+PPA was considered. The proposed classification can be broadly applicable to assess the conservation status of ecosystems elsewhere, using similar conceptual and methodological tools. The development of functional ecosystem classifications for different countries must be encouraged to facilitate monitoring of global conservation targets.
Palabras claves: Ecosystem approach, Biodiversity conservation, Functional traits, Protected areas
Referencia APA: Martínez-Tilleria, K., Núñez-Ávila, M., León, C., Pliscoff, P., Squeo, F., & Armesto, J. (2017). A framework for the classification Chilean terrestrial ecosystems as a tool for achieving global conservation targets. Biodiversity And Conservation, 26(12), 2857-2876. http://dx.doi.org/10.1007/s10531-017-1393-x
The importance of scale-dependent ravine characteristics on breeding-site selection by the Burrowing Parrot, Cyanoliseus patagonus
Ramirez-Herranz, M., Rios, R., Vargas-Rodriguez, R., Novoa-Jerez, J. and Squeo, F.
In birds, the environmental variables and intrinsic characteristics of the nest have important fitness consequences through its influence on the selection of nesting sites. However, the extent to which these variables interact with variables that operate at the landscape scale, and whether there is a hierarchy among the different scales that influences nest-site selection, is unknown. This interaction could be crucial in burrowing birds, which depend heavily on the availability of suitable nesting locations. One representative of this group is the burrowing parrot, Cyanoliseus patagonus that breeds on specific ravines and forms large breeding colonies. At a particular site, breeding aggregations require the concentration of adequate environmental elements for cavity nesting, which are provided by within ravine characteristics. Therefore, intrinsic ravine characteristics should be more important in determining nest site selection compared to landscape level characteristics. Here, we assess this hypothesis by comparing the importance of ravine characteristics operating at different scales on nest-site selection and their interrelation with reproductive success. We quantified 12 characteristics of 105 ravines in their reproductive habitat. For each ravine we quantified morphological variables, distance to resources and disturbance as well as nest number and egg production in order to compare selected and non-selected ravines and determine the interrelationship among variables in explaining ravine differences. In addition, the number of nests and egg production for each reproductive ravine was related to ravine characteristics to assess their relation to reproductive success. We found significant differences between non-reproductive and reproductive ravines in both intrinsic and extrinsic characteristics. The multidimensional environmental gradient of variation between ravines, however, shows that differences are mainly related to intrinsic morphological characteristics followed by extrinsic variables associated to human disturbance. Likewise, within reproductive ravines, intrinsic characteristics are more strongly related to the number of nests. The probability of producing eggs, however, was related only to distance to roads and human settlements. Patterns suggest that C. patagonus mainly selects nesting sites based on intrinsic morphological characteristics of ravines. Scale differences in the importance of ravine characteristics could be a consequence of the particular orography of the breeding habitat. The arrangement of resources is associated to the location of the gullies rather than to individual ravines, determining the spatial availability and disposition of resources and disturbances. Thus, nest selection is influenced by intrinsic characteristics that maximize the fitness of individuals. Scaling in nest-selection is discussed under an optimality approach that partitions patch selection based on foraging theory.
Palabras claves: Nesting site, Burrowing bird, Intrinsic morphological characteristic, Foraging, Landscape variables.
Referencia APA: Ramirez-Herranz, M., Rios, R., Vargas-Rodriguez, R., Novoa-Jerez, J. and Squeo, F. (2017). The importance of scale-dependent ravine characteristics on breeding-site selection by the Burrowing Parrot, Cyanoliseus patagonus. PeerJ, 5, p.e3182. https://doi.org/10.7717/peerj.3182
Genetic variation of loci potentially under selection confounds species–genetic diversity correlations in a fragmented habitat
Bertin, A., Gouin, N., Baumel, A., Gianoli, E., Serratosa, J., Osorio, R. and Manel, S.
Positive species–genetic diversity correlations (SGDCs) are often thought to result from the parallel inﬂuence of neutral processes on genetic and species diversity. Yet, con-founding effects of non-neutral mechanisms have not been explored. Here, we investigate the impact of non-neutral genetic diversity on SGDCs in high Andean wetlands.We compare correlations between plant species diversity and genetic diversity (GD)calculated with and without loci potentially under selection (outlier loci). The study system includes 2188 specimens from ﬁve species (three common aquatic macroinvertebrate and two dominant plant species) that were genotyped for 396 ampliﬁed fragment length polymorphism loci. We also appraise the importance of neutral processes onSGDCs by investigating the inﬂuence of habitat fragmentation features. Signiﬁcant positive SGDCs were detected for all ﬁve species (mean SGDC = 0.52 0.05). While only a few outlier loci were detected in each species, they resulted in signiﬁcant decreases in GD and in SGDCs. This supports the hypothesis that neutral processes drive species–genetic diversity relationships in high Andean wetlands. Unexpectedly, the effects on genetic diversity GD of the habitat fragmentation characteristics in this study increased with the presence of outlier loci in two species. Overall, our results reveal pitfalls in using habitat features to infer processes driving SGDCs and show that a few loci potentially under selection are enough to cause a signiﬁcant downward bias in SGDC. Investigating confounding effects of outlier loci thus represents a useful approach to evidence the contribution of neutral processes on species–genetic diversity relationships.
Palabras claves: Community genetics, connectivity, habitat, high Andean wetlands, outlier loci,species–genetic diversity correlations.
Referencia APA: Bertin, A., Gouin, N., Baumel, A., Gianoli, E., Serratosa, J., Osorio, R. and Manel, S. (2017). Genetic variation of loci potentially under selection confounds species-genetic diversity correlations in a fragmented habitat. Molecular Ecology, 26(2), pp.431-443. dx.doi.org/10.1111/mec.13923
Rootstock effect on irrigated grapevine yield under arid climate conditions are explained by changes in traits related to light absorption of the scion
Bascuñán-Godoy, L., Franck, N., Zamorano, D., Sanhueza, C., Carvajal, D., & Ibacache, A.
The purpose of this study was to investigate the mechanisms underlying the effect of rootstocks on table grapevines grown under irrigated conditions in the arid North macro-zone of Chile.
Grapevine cv. Red Globe grafted onto three rootstocks (Harmony, Saint George and Salt Creek) were studied Structural and physiological parameters were monitored at different phenological stages under optimal production conditions.
An outstanding yield increment brought about by the rootstocks Harmony and Salt Creek was correlated with increased individual leaf and specific leaf area, pruning weight (proxy for total leaf area), photosynthesis per unit leaf mass, sugar in leaves and root carbon reserves. In addition, these high yielding rootstocks induced higher contents of light-harvesting chlorophyll a/b protein of photosystem II and total chlorophyll in the leaves of the scion. No correlations of yield with traits involved in water use (relative water content or instantaneous water use efficiency) were observed.
The effects of rootstocks on the light capture capacity of the scion directly affected carbon assimilation and storage and, accordingly, yield. Therefore, the identified traits are valuable targets for screening and selecting yield efficient rootstocks for irrigated table grape production in arid zones.
Palabras claves: Grapevine rootstock, Light capture, Photo synthesis, Pruning weight, Red Globe, Yield
Referencia APA: Bascuñán-Godoy, L., Franck, N., Zamorano, D., Sanhueza, C., Carvajal, D., & Ibacache, A. (2017). Rootstock effect on irrigated grapevine yield under arid climate conditions are explained by changes in traits related to light absorption of the scion. Scientia Horticulturae, 218, 284-292. http://dx.doi.org/10.1016/j.scienta.2017.02.034
Surface water quality in a sulfide mineral-rich arid zone in North-Central Chile: Learning from a complex past, addressing an uncertain future
Flores, M., Núñez, J., Oyarzún, J., Freixas, G., Maturana, H., & Oyarzún, R.
This study presents an analysis of up to 30 years of hydrological variables and selected water quality parameters (pH, SO4, Fe, Cu, and As) in the upper area of the Elqui River basin in North‐Central Chile. A correlation analysis determined statistically significant positive relationship for SO4‐Cu, Fe‐As, and Fe‐Cu. In terms of historical behaviour, no statistically significant
trends were detected for precipitation or temperature. In contrast, for flow, there is an overall decreasing pattern for the entire area of study, although only in one case this trend was statistically significant. Along with the aforementioned analysis, a characterization of the flow‐water quality relationships is considered for the time period analyzed. Although erratic behaviours were confirmed, a negative (i.e., inverse) flow‐concentration relationship was identified for SO4, a positive (i.e., direct) relationship for Fe, and undefined relationships for As and Cu were obtained.
From these analyses and based on previous studies on projections regarding climate change for the Andean region, and in particular for the upper Elqui zone, an estimation of the possible effects of the change in water regimes on water quality in the area of study is developed. It is likely that a decrease in surface flow, as a consequence of climate change could translate into improvements in water quality in terms of Fe and eventually As and Cu, but into an impairment in the case of
SO4. In any case, this is a complex situation that demands special attention in the face of industrial activities that could be developed in tributaries like the Claro River, which currently play an important role in depurating or diluting contaminants in the waters of the Elqui River. Finally, it should be noted that this study addresses an issue that goes beyond the local interest and could be used as a reference to compare other transitional environments containing sulphide ores or areas of hydrothermal alterations, which are considered to be highly vulnerable to climate change and variability.
Palabras claves: acid rock drainage, Andean river, arid zone, Coquimbo region
Referencia APA: Flores, M., Núñez, J., Oyarzún, J., Freixas, G., Maturana, H., & Oyarzún, R. (2016). Surface water quality in a sulfide mineral-rich arid zone in North-Central Chile: Learning from a complex past, addressing an uncertain future. Hydrological Processes, 31(3), 498-513. http://dx.doi.org/10.1002/hyp.11086
Rainfall, microhabitat, and small mammals influence the abundance and distribution of soil microorganisms in a Chilean semi-arid shrubland.
Aguilera, L., Armas, C., Cea, A., Gutiérrez, J., Meserve, P., & Kelt, D.
Patterns in rainfall and soil water availability are considered to be the main drivers governing arid and semiarid ecosystems. While the mechanisms by which water limits aboveground net primary production has been widely explored, few long-term studies have examined interactions between precipitation, soil resources, plant communities, and soil microbial communities; these may be critical to understanding soil biogeochemical cycles and above- and belowground interactions. We capitalized on a long-term biotic manipulation (exclusion of small mammal herbivores from replicate plots) and long-term variation in rainfall to assess how precipitation, small mammals, and shrub cover act directly and interactively to influence the spatial and temporal distribution of soil microorganisms, a key first step to understanding soil biogeochemical cycles. We measured the abundance of arbuscular mycorrhiza (AM), soil fungi, soil bacteria, and soil physicochemical characteristics over 10 consecutive years in a semiarid thorn scrub community in north–central Chile; we sampled two microhabitats (under shrub cover, and in open spaces between shrubs colonized by ephemeral plants), and in plots with or without the presence of native small mammals, the main herbivores in this environment. Annual rainfall ranged widely (11–356 mm) in this period and was the primary factor affecting abundance of AM root colonization and soil microbes. While the percentage of root length with AM was higher in dry compared to wet years, free-living soil bacteria and fungi were more abundant during wet years. All microorganisms were more abundant in the resource islands beneath the shrubs compared to open microhabitat between shrubs, although the relation between soil biota and the concentration of some particular nutrients was negative. These patterns were modulated by the presence of small mammals, which enhanced root colonization by AM fungi, particularly for ephemeral plants, but which were negatively associated with soil fungi abundance. The abundance of soil bacteria showed a more complex response to the presence of small mammals and was dependent on microhabitat and year. The spatial and temporal heterogeneity of soil resources and the activity of small mammals are important modulators of subterranean biotic responses to rainfall, the primary factor affecting soil microbiota abundance in this semiarid ecosystem.
Palabras claves: ENSO; LTSER; Plant-soil interactions; Mycorrhizal fungi; Soil filamentous fungi; Soil heterotrophic bacteria; Soil yeasts.
Referencia APA: Aguilera, L., Armas, C., Cea, A., Gutiérrez, J., Meserve, P., & Kelt, D. (2016). Rainfall, microhabitat, and small mammals influence the abundance and distribution of soil microorganisms in a Chilean semi-arid shrubland. Journal Of Arid Environments, 126, 37-46.
Shrub–ephemeral plants interactions in semiarid north-central Chile: Is the nurse plant syndrome manifested at the community level?.
Madrigal-González, J., Kelt, D., Meserve, P., Squeo, F., & Gutiérrez, J.
Models of plant–plant interactions suggest that nurse plants are critical for the maintenance of biodiversity and ecosystem functions in arid and semiarid lands. At the community scale, however, empirical support of this idea is limited and context-dependent. Following on a preliminary work which suggested that a dominant shrub in north-central Chile (Porlieria chilensis) had nurse plant effects, we tested the effects of this and two other shrubs (Adesmia bedwellii and Proustia cuneifolia) on community biomass production, species density, and species composition of ephemeral plants in the semiarid scrub of the Bosque Fray Jorge National Park (Chile) over four consecutive years. We tested for main and interactive effects of shrubs and precipitation on total biomass production and species density of ephemeral plant communities using Generalized Linear Mixed Models (GLMM). To analyze the effects of shrubs and precipitation on species composition we used Canonical Correspondence Analysis (CCA) and t-value biplot analysis. Total biomass production increased significantly with precipitation and was consistently lower beneath shrub canopies, particularly under A. bedwellii and P. chilensis. Although ephemeral plant species density generally was higher in open areas, differences between open and shrub canopy samples diminished with increasing precipitation. Finally, despite significant differences in ephemeral plant species composition between open areas and shrub canopies, we found no evidence of shrub species-specific effects. In conclusion, our results do not support a classical nurse plant syndrome in the semiarid scrub of the Bosque Fray Jorge National Park although shrubs can increase local diversity by favoring some ephemeral plant species that are absent in open areas.
Palabras claves: Ephemeral plant communities; Facilitation; Nurse plant syndrome; Precipitation; Semiarid scrub; Biomass production; Diversity.
Referencia APA: Madrigal-González, J., Kelt, D., Meserve, P., Squeo, F., & Gutiérrez, J. (2016). Shrub–ephemeral plants interactions in semiarid north-central Chile: Is the nurse plant syndrome manifested at the community level?. Journal Of Arid Environments, 126, 47-53.
Bet-hedging strategies of native and exotic annuals promote coexistence in semiarid Chile.
Jiménez, M., Gaxiola, A., Armesto, J., González-Browne, C., Meserve, P., & Kelt, D., Gutierrez, J.R., Jaksic, F.M.
Scientists are increasingly interested in the evolutionary responses of organisms to unpredictable, variable, and extreme climate changes. In semiarid environments, inter-annual variability in the frequency and amount of rainfall affects both the growth and recruitment of plant species, especially annuals. In these inherently variable environments, individual selection should favor demographic responses that spread the risk of mortality over time and enhance long-term reproductive success (i.e., bet-hedging strategies). However, the same processes that allow the persistence and recruitment of native species could facilitate the introduction and establishment of exotics. We assessed whether native and exotic annuals in semiarid Chile displayed similar or contrasting bet-hedging traits, and discuss mechanisms of coexistence of both types of species and their demographic variation under interannual rainfall variability driven by El Niño Southern Oscillation (ENSO). We analyzed a proxy of long-term fitness, i.e., the variability of seed density over 17 years, for the two most common native and two exotic annual plant species present in the study area. We experimentally tested whether the quality of the maternal environment (soil water supply in a given year) had an extended effect (e.g. the next year) on the proportion of seed germination or on the mean and/or variability of seed size and seed dormancy. Results showed that native and exotic species in this annual plant assemblage displayed contrasting bet-hedging strategies as evolutionary responses to variable rainfall. Although rainfall variability promotes the evolution of bet-hedging strategies, the nature of these strategies varies across species, presumably to minimize competitive exclusion. In semiarid Chile, the success of two exotic ephemerals that are components of a diverse community of native annual species seems to reflect bet-hedging germination strategies that complement rather than compete with those expressed in dominant natives.
Palabras claves: Bromus; Coexistence; Germination; Long-term fitness; Storage effect.
Referencia APA: http://dx.doi.org/10.1016/j.jaridenv.2015.10.014
Patterns in arthropod abundance and biomass in the semiarid thorn scrub of Bosque Fray Jorge National Park, north-central Chile: A preliminary assessment.
Meserve, P., Vásquez, H., Kelt, D., Gutiérrez, J., & Milstead, W.
In 2003, we initiated a sampling protocol for arthropods as part of long-term field experiment in a semiarid thorn scrub community in north-central Chile. We utilized pitfall and Malaise traps to sample terrestrial and volant arthropods, respectively. Inventories were conducted for 4 days and nights monthly. We posited that arthropod abundance and biomass would track environmental changes such as high rainfall often due to El Niño Southern Oscillations (ENSOs). Peaks in both abundance and biomass for terrestrial and volant arthropods were in similar months (spring–early summer; August–November); arthropods also tracked high rainfall years in 2004, 2006, and 2011, due mostly to increases in a few dominant groups, i.e., tenebrionid beetles (Coleoptera) in terrestrial sampling, and moths (Lepidoptera: Noctuidae, microlepidoptera) in aerial sampling. However, the same groups increased dramatically in 2008 which was a below-average rainfall year. Numerical decreases in late summer-fall months (January–April) were more abrupt for terrestrial arthropods than for volant ones. Both terrestrial and volant arthropods reached their lowest levels in winter months (June–July). Some evidence suggests long-term shifts in the composition of volant taxa. Arthropods likely are important prey items for insectivorous reptiles (i.e., lizards), birds, and an insectivorous small mammal, the elegant mouse opossum (Thylamys elegans), and future efforts are being directed towards examining the evidence for correlated changes in those consumers with arthropod abundance and biomass.
Palabras claves: Long-term studies; Climate change; Arthropods; Semiarid systems; Chile.
Referencia APA: Meserve, P., Vásquez, H., Kelt, D., Gutiérrez, J., & Milstead, W. (2016). Patterns in arthropod abundance and biomass in the semiarid thorn scrub of Bosque Fray Jorge National Park, north-central Chile: A preliminary assessment. Journal Of Arid Environments, 126, 68-75.
El Niño Southern Oscillation drives conflict between wild carnivores and livestock farmers in a semiarid area in Chile.
Acosta-Jamett, G., Gutiérrez, J., Kelt, D., Meserve, P., & Previtali, M.
The warm phase of El Niño-Southern Oscillation (ENSO) events results in greatly elevated rainfall in north-central Chile, with dramatic effects on small mammals and vertebrate carnivore abundances. In ensuing cool phases of ENSO, plant cover decreases, followed by small mammal densities, in turn affecting the resource availability for their predators. Wild carnivores such as foxes are one of the main predators of small mammals; when the latter decline, foxes could exhibit functional responses, increasing their consumption of domestic livestock. To our knowledge, the influence of native prey abundance on livestock predation has not been assessed. We hypothesize that periods of scarce native prey increases conflicts between carnivores and farmers outside protected areas, especially during drought years. From 1990 to 2005 we used live trapping to determine monthly density of small mammals in a national park (Bosque Fray Jorge National Park, BFJNP) in north-central Chile; rainfall was also monitored. We calculated an index of predation as the number of sheep predated by foxes annually on one farm (encompassing ca. 45,000 ha) located in the vicinity of BFJNP. Path analysis was carried out to assess factors influencing sheep predation by wild foxes. Factors included precipitation and small mammal density. Small mammal density correlated positively with two years moving average of rainfall. Sheep predation by foxes increased after of two years of low rainfall. Our findings suggest that wild carnivores employ functional responses in response to varying prey availability, shifting from wild to domestic prey during periods of drought, which could have important conservation and management implications.
Palabras claves: Wild foxes; Livestock predation; Drought; Coquimbo region; Chile.
Referencia APA: Acosta-Jamett, G., Gutiérrez, J., Kelt, D., Meserve, P., & Previtali, M. (2016). El Niño Southern Oscillation drives conflict between wild carnivores and livestock farmers in a semiarid area in Chile. Journal Of Arid Environments, 126, 76-80.
Biotic interactions and community dynamics in the semiarid thorn scrub of Bosque Fray Jorge National Park, north-central Chile: A paradigm revisited.
Meserve, P., Kelt, D., Gutiérrez, J., Previtali, M., & Milstead, W.
In 1989, we initiated a long-term field experiment in a semiarid thorn scrub community in north-central Chile. We posited that biotic interactions, particularly predation, interspecific competition, and herbivory assumed a primary top-down role in affecting small mammals and annual plants here. Using a multi-factorial design we selectively excluded vertebrate predators (principally carnivores and raptors) and a large small mammal herbivore, the degu (Octodon degus), from replicated 0.56 ha exclosures located in a valley near the coast in Bosque Fray Jorge National Park. Evidence initially supported effects of predator exclusion on O. degus but not for other small mammals in the assemblage (e.g., Phyllotis darwini, Abrothrix olivaceus). Subsequent years of monitoring have documented that predation has temporary effects on degu numbers, but that populations of this and other small mammals are much more strongly influenced by environmental bottom-up factors (i.e., rainfall). Further, our experimental manipulation has provided no evidence for negative interspecific competition effects on numbers of any small mammal in this assemblage. Degu exclusions, however, have had negative indirect effects on exotic annuals; native annuals appear to outcompete exotics especially during drought years The effect is magnified in all-small mammal exclusions. Since about 2002, selective exclusions of lagomorphs and small mammals have resulted in changes in cover of some perennial shrubs. Also notable has been a fundamental shift in the small mammal composition following the last major El Niño Southern Oscillation (ENSO) event in 2000–2002; degus now comprise a majority of small mammal biomass in the assemblage, and their numbers have become more stable and less temporally variable. This appears to have been caused by a shift in rainfall periodicity from strong interannual fluctuations in response to periodic ENSOs, to a more equitable pattern with more consistent annual rainfall. This represents one of the first documented cases of system-wide biotic phase shifts to a relatively modest change in rainfall regime. This may be indicative of ongoing climate change in the Chilean semiarid region, and we expect that further changes in the community will occur if those trends continue.
Palabras claves: Long-term studies; Population; Community ecology; Small mammals; Chile.
Referencia APA: Meserve, P., Kelt, D., Gutiérrez, J., Previtali, M., & Milstead, W. (2016). Biotic interactions and community dynamics in the semiarid thorn scrub of Bosque Fray Jorge National Park, north-central Chile: A paradigm revisited. Journal Of Arid Environments, 126, 81-88.
Where does the water go? Understanding geohydrological behaviour of Andean catchments in south-central Chile.
Arumí, J., Maureira, H., Souvignet, M., Pérez, C., Rivera, D., & Oyarzún, R.
Upper Diguillín and Renegado are two neighbouring Andean basins of south-central Chile, with different specific discharges that cannot be explained solely by their difference in size. To address this issue, this study considers three separate but complementary approaches: (a) long-term analysis of rainfall and flow trends; (b) determination of hydrogeological properties at the watershed scale; and (c) analysis of the temporal evolution of groundwater storage. First, a trend test detected a statistically significant discharge decrease for Renegado in summer, unrelated to a coincidental precipitation trend, which seems to be associated with an increased use of water in that season related to tourism activity in the area. Second, there were no important differences in hydraulic conductivity or drainable porosity between the two study areas. However, it was found that there is a long-term negative trend in groundwater storage for Renegado; that is, water that contributes to the lower Diguillín streamflow through numerous springs.
Palabras claves: Basin-scale hydrology, Brutsaert analysis, trend analysis, baseflow.
Referencia APA: Arumí, J., Maureira, H., Souvignet, M., Pérez, C., Rivera, D., & Oyarzún, R. (2016). Where does the water go? Understanding geohydrological behaviour of Andean catchments in south-central Chile. Hydrological Sciences Journal, 1-12.