Scielo RSS <![CDATA[Revista chilena de historia natural]]> vol. 91 num. lang. en <![CDATA[SciELO Logo]]> <![CDATA[Protected areas in Chile: are we managing them?]]> Abstract Background Human population growth since the mid-1900s has been accompanied by an unsustainable use of natural resources and a corresponding impact on terrestrial and marine biota. In response, most states have established protected areas as tools to decrease biodiversity loss, being Chile one of the signatories of international conservation agreements such as the Convention on Biological Diversity (CBD) and the 2010 Aichi Targets. This study reviews the Chilean protected areas that have been created to date, with an emphasis on the existence and effectiveness of management plans for all terrestrial and marine protected areas. Effectiveness was individually evaluated using two filters: 1) the age of the management plan and 2) the first four steps of the Protected Areas Management Effectiveness (PAME) methodology recommended by the IUCN. Results We show that 84 out of a total of 145 protected areas (PAs), and only five out of a total of 20 marine protected areas (MPAs), have management plans. Only 12% (N = 16) of PAs are effectively managed; while in the marine realm, no MPA has an effective plan. Conclusions Our results show the lack of both the effectiveness of and updates to the management plans for the vast majority of the national territory and raise the following question: is it sustainable to continue adding protected areas to the national system even though it is clear that the existing support is insufficient to meet the minimum requirements for full implementation? <![CDATA[A modularity-based approach for identifying biodiversity management units]]> Abstract Background Taxon- and/or ecosystem-based definitions of management units typically focus on conspicuous species and physical habitat limits; these definitions implicitly assume that these classification systems are related to the mechanisms that determine biodiversity persistence. However, ecological theory shows that this assumption may not be supported. Herein, we introduce the use of modularity analysis for objectively identifying management units and topological roles that land cover type plays on species movement through the landscape. Methods As a case study, we used a coastal system in Uruguay, with 28 land cover types and five taxa (from plants to mammals). A modularity-based approach was used to identify subsets of habitats with biotic affinity, termed modules, across the different taxonomic groups. Modularity detects the tendency of some land cover types to have a higher probability of the mutual interchange of individuals than other land cover types. Based on this approach, pairs of habitats that co-occur in the same module across taxa were considered in the same biodiversity management units (BMU). In addition, the topological role of each habitat was determined based on the occurrence of species through the landscape. Results Our approach determined three management units that combine land cover types usually considered independent, but instead are interrelated by an occurrence-based ecological network as proxies of the potential flow of individual and land use. For each selected taxon, the specific topological role of each habitat was determined. Conclusions This approach provides an objective way of delineating spatial units for conservation assessment. We showed that land cover types within these spatial units could be identified as refuges for specific types of biodiversity, sources of propagules for neighboring or overall landscapes, or stepping-stones connecting sub-regions. The preservation of these topological roles might help maintain the mechanisms that drive biodiversity in the system. Interestingly, the role of land cover type was strongly contingent on the taxa being considered. The method is comprehensible, applicable to policy and decision-makers, and well-connected with ecological theory. Moreover, this approach complements existing methods, introduces novel quantitative uses of available information, determines criteria for land cover classification and identifies management units that are not evident through other approaches. <![CDATA[A citizen-based platform reveals the distribution of functional groups inside a large city from the Southern Hemisphere: e-Bird and the urban birds of Santiago (Central Chile)]]> Abstract Background: Current knowledge of urban bird ecology and biodiversity relies on evidence from cities of the Northern Hemisphere, while the Southern Hemisphere is underrepresented. Santiago is a large city from South America, located in central Chile, which is both a biodiversity hotspot and an Endemic Bird Area. This work is a synthesis, which aims to provide a diversity account for Santiago, and to describe the broad geographic distribution and bird functional patterns. Methods: We synthesized a seven-year (2009-2016) bird register from the eBird database (21,865 georeferenced registers at Santiago) into a single avifaunal account, along with the observed number of individuals. We complemented these registers by using available literature about Santiago's avifauna (28 references). We investigated the proportion of native/exotic, migrants/residents, conservation categories, and urban nesting status. We classified Santiago's birds into seven trophic guilds. We plotted species richness and number of individuals for each functional group, by interpolating trough the Inverse Distance Weighted Method. Results: We found that Santiago's avifauna (46 species) is composed mainly by native (41), resident (38), non-threatened species (46) that breed inside the city (31). Some functional groups inhabit a large portion of Santiago's urban surface, reaching high values of richness and abundance. Among these groups are the native, urban-nesters and resident species; even though exotics possess low species richness (5), they are abundant and inhabit the complete urban surface of the city. The dominant trophic guilds are omnivorous (11) and granivorous (10). Insectivorous are the third most abundant trophic guild, and show the highest species richness (13). Conclusion: The functional groups with lower species richness are less abundant and display reduced and patchy distributions in Santiago. This is probably because of the low availability of suitable habitats and/or restricted food supply (migrants, carnivorous, nectarivorous, frugivorous, herbivorous and piscivorous). The high insectivorous richness reported in Santiago, along with similar patterns reported in several cities in the Neotropics, provides evidence to postulate a pattern of high species richness of this guild in cities across this biogeographic realm. <![CDATA[Plant composition and structure of two post-livestock areas of Tamaulipan thornscrub, Mexico]]> Abstract Background The composition, structure and biological diversity of two regenerated areas after livestock activities in a Tamaulipan thornscrub vegetation from Northeast Mexico were evaluated. The regeneration of each area was evaluated with the establishment of 12 sampling sites of 50m2. From the data obtained ecological indexes such as: Importance Value Index and Diversity (alpha and beta) were evaluated. Results A total of 17 families, 40 genera and 42 species were registered, the most representative family was Fabaceae with 11 spp. The intensive livestock area had 36 species; a Margalef index of 4.44 and a 1.24 Shannon index, while the extensive livestock area had 32 species, a Margalef index of 4.24 and a 2.16 Shannon index. The communities evaluated have a (48%) mean similarity. Conclusions 1) Regenerated communities after livestock use showed higher richness of species and alpha diversity. 2) Evaluated communities have a mean similarity of (48%). 3) Even after 25 years of regeneration the most dominant species was Cenchrus ciliaris that is used for cattle forage. <![CDATA[Sexual and asexual reproductive aspects of <em>Leontochir ovallei,</em> a rare and endangered geophyte of the Atacama Desert]]> Abstract Background “Garra de Leon” (Leontochir ovallei) is an ephemeral endangered Alstroemeriaceae species endemic to Chile. Despite many efforts to improve the conservation of this species, the stimulation of dormant seeds and the production of rhizomes under controlled conditions remain unexplored. The aims of this study were to examine the germination responses of L. ovallei seeds under different in vitro conditions and to evaluate the formation of viable rhizomes after transplantation from in vitro to ex vitro conditions. Methods We evaluated five in vitro seed germination treatments: (1) acid scarification, (2) acid scarification followed by imbibition of seeds in aerated water, (3) imbibition of seeds in gibberellic acid, (4) clipping of seeds with a scalpel, and (5) seeds without any treatment (control). Seedlings obtained under in vitro conditions were transplanted to ex vitro conditions following a gradual acclimation process. After eight months, the number of rhizomes per plant was counted. To test asexual multiplication, each rhizome with its respective storage organ was divided using a scalpel and then left to rest for two years before subsequent evaluation of viability. After that period, the rhizomes were re-hydrated, and the emergence of plants after three months was evaluated. Results Seeds exposed to treatment 2 showed the highest germination percentage (36%), followed by the seeds whose coats were clipped (14%) and seeds treated with sulphuric acid (8%). The seed germination of the control treatment was 3%. After transplantation to ex vitro conditions, we obtained 220 rhizomes, with an average of three to six rhizomes per plant. After two years of dormancy, a total of 34 rhizomes (of 220 rhizomes) reactivated growth after re-ydration, indicating that, at least, 15,5% responded positively to watering. Conclusions We found that the seed germination of L. ovallei was increased by strong acidic conditions, suggesting that the main type of seed dormancy in this species is physical. However, germination was further increased by aeration, indicating embryo dormancy. In addition, we were able to obtain viable rhizomes by transplanting seedlings from in vitro to ex vitro conditions, which may be helpful for the propagation and ex situ conservation of this rare geophyte of Chile and potentially other geophyte species adapted to wet-dry cycle environments. <![CDATA[Heavy metal biomagnification and genotoxic damage in two trophic levels exposed to mine tailings: a network theory approach]]> Abstract Background The analysis of the negative effects of environmental metal pollution is complex and difficult to assess, because the great number of variables and levels of biological organization involved. Therefore, an integral interpretation of the structure of ecological interactions from the multifactorial toxicological vision can be achieved by the use of new analysis tools, such as the complex network theory analysis (CNT). Results Our results demonstrated that the trophic level has an effect on metal enrichment, being the detritivores who presented the highest bioaccumulation levels in comparison to plants, as well as higher biomagnification levels in the soil-plant-detritivores relationship. Also, Vachellia farnesiana displayed greater sensitivity to genotoxic damage than Eisenia fetida. Finally, the analysis of complex networks showed that detritivores are the key link in this dynamics, on which the interactions between heavy metals, plant and detritivores depend. Conclusions This study shows that there is an effect of the study site on heavy metal bioaccumulation and DNA damage induction, and that these responses are particular to each species and to each bioaccumulated metal, which in turn reveals specific sensitivity for each trophic level. Moreover, the application of CNT methodology allowed us to clarify in this particular system, the interaction types and the principal components of the trophic structure. <![CDATA[Ultrastructure of sensilla on antennae and maxillary palps in three Mesembrinellidae species]]> Abstract Background Having the right identification is essential in the field of entomology. The scanning electron microscopy allows rapid and accurate identification of different species of flies since a better visualization of the external morphology of immature and some adults is possible. The aim of this study is to describe some ultrastructures of three flies in the Mesembrinellidae family: Mesembrinella bellardiana; Mesembrinella bicolor and Mesembrinella semihyalina, all examined by scanning electron microscopy to help increase the anatomical database on flies and deal with phlylogenetic implications. Results The flies were examined under JEOL 6390LV scanning electron microscope (SEM). The microtrichia morphology of the antennae is similar to that of other and are present on all antennal surface with variable distribution. The chaetic sensilla were observed only in the scape (chaetic sensilla I) and pedicel segments (chaetic sensilla I-III). Three types of sensilla: trichoidea, basiconic and clavate were observed in the first flagellomere of M. bellardiana; and two types of sensilla: trichoidea and basiconic were noticed in M. bicolor and M. semihyalina. Olfactory pits were observed in both gender of M. bellardiana and female of M. bicolor . The maxillary palp of the Mesembrinella species in this study does not show sexual dimorphism. Conclusion This investigation provided new findings of some diagnostic structures of flies using SEM, since many of them could have not been observed just by the use of light microscopy. <![CDATA[Evolution of trans-Andean endemic fishes of the genus <em>Cheirodon</em> (Teleostei: Characidae) are associated with chromosomal rearrangements]]> Abstract Background Among Neotropical fishes, the family Characidae is highly diverse and speciose and its taxonomy is not completely resolved. In Chile, the family is represented by five species, all within the genus Cheirodon , of which C. pisciculus, C. galusdae, C. kiliani , and C. australe are endemic , while C. interruptus is introduced. We compared chromosomal markers in order to appreciate the taxonomy and evolution of these trans-Andean fishes. Results The specimens were photographed in stereomicroscope to observe the ventral protrusive teeth and cusps for morphological analysis and species identification. All of the species analysed had equally diploid chromosome number 2n = 50, with karyotypes dominated by high number of acrocentric chromosomes as compared to those of other members of Cheirodontinae. The distribution of heterochromatin was inconspicuous and was similar in all the species. The number of active NORs (nucleolus organizer regions) was polymorphic, with the greater number of them in C. kiliani and C. galusdae . The location of 5S and 18S rDNA ranged in number and position, showing two sites in different chromosomes. The fluorescent in situ hybridization with telomeric probe did not reveal interstitial sites in all analysed species. Conclusions The comparative analysis of karyotypes and morphological markers revealed a biogeographic pattern of distribution, with the species that occur in the southern region forming one group and those in central and northern Chile forming another. <![CDATA[Effect of <em>Didymosphenia geminata</em> coverage on the phytobenthic community in an Andean basin of Chile]]> Abstract Background: The invasive diatom Didymosphenia geminata (Lyngbye) M. Schmidt has received considerable attention in recent years due to its rapid geographic expansion and massive proliferation, which have altered habitat availability for benthic species and triggered negative effects on stream ecosystems. We evaluated the changes in the community structure of phytobenthos caused by the temporal variation in D. geminata coverage, in addition to the environmental variables correlated with the temporal variation of this invasive microalga in the Andean sector of the Biobio River basin, Chile. Methods: Environmental parameters were measured during the austral summer of 2014-2015, when phytobenthos samples were collected and used to develop a relative abundance matrix of taxa by calculating species richness and Shannon diversity. Multivariate techniques were used to establish the relationships among environmental variables, including D. geminata coverage, and the phytobenthic community. Results: Massive proliferation of D. geminata occurs during summer (December-January). According to multiple regression analysis, electrical conductivity, temperature and total phosphorus were the variables that best explained the variation in D. geminata coverage. When D. geminata coverage was over 50%, phytobenthic species richness was significantly higher than at the uninvaded site, without a significant change in Shannon diversity. In addition, the % coverage of this invasive microalga and total phosphorus concentration were variables that differentiated phytobenthic communities among the study sites. Conclusions: Environmental factors such as conductivity, temperature and total phosphorus concentration influenced the temporal variability of D. geminata mats. In addition, the massive growth of this invasive diatom caused a higher species richness without altering Shannon diversity. Our results suggest that the spatio-temporal variability of D. geminata correlated with environmental variables will help predict the habitat suitability of this alga in other Andean rivers and allow a better understanding of ecological habitat alterations. <![CDATA[Frugivory and seed dispersal in the endemic cactus <em>Eulychnia acida</em>: extending the anachronism hypothesis to the Chilean Mediterranean ecosystem]]> Abstract Background: Eulychnia acida is an endemic Chilean cactus species whose fruits show several traits that, taken as a whole, are compatible with a seed dispersal syndrome by large herbivore vertebrates. Since only a few large native mammals exist in Chile at present, cactus fruit consumption and seed dispersal may be coopted by introduced mammals as predicted by Janzen and Martin's (1982) hypothesis for tropical ecosystems. Findings: We describe the current frugivore species of E. acida in a protected semiarid-Mediterranean ecosystem using field measurements and feeding experiments. In addition, to examine a potential role as seed dispersers of the cactus species, we offered fruits and performed germination tests on seeds defecated by Lama guanicoe and the introduced goat Capra a. hircus under captivity conditions. Our data indicate that while fruits of E. acida are pecked by the Chilean tinamou, Nothoprocta perdicaria, and the Chilean mockingbird, Mimus thenca, and eaten by the brush-tailed rodent, Octodon degus, none of these species could be considered a legitimate seed disperser. Unlike L. guanicoe, the goat C. a. hircus did not reduce seed germination, having a neutral effect. Conclusions: Results from this study indicate that introduced C. a. hircus was the only species showing a potential role in the seed dispersal process of E. acida. In the absence of native frugivore species, goats might play an important role in population recruitment of the endemic cactus. These results extend Janzen and Martin's(1982) anachronism hypothesis to the Chilean Mediterranean ecosystem.