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CITATIONS 2 READS 41 4 authors: Some of the authors of this publication are also working on these related projects: Soybean pollination. A multiscale approach. View project Abstract In Gondwanic Discaria, phenotypically intermediate individuals exist between Discaria chacaye (G. Don) Tortosa and Discaria articulata (Phil.) Miers, and between D. chacaye and related Ochetophila trinervis (Gillies ex Hook. & Arn.) Poepp. ex Miers.

Artículo publicado en Open Access bajo los términos de Creative Commons attribution Non Comercial License 3.0. MONOGRÁFICO: Pérdida de polinizadores: evidencias, causas y consecuencias ecosistemas REVISTA CIENTÍFICA DE ECOLOGÍA Y MEDIO AMBIENTE

In this work, we describe a method that allows the extraction of plant genomic DNA from frozen enzyme homogenates. To test if reliable DNA was recovered from allozyme extracts, we compared these results with that obtained from fresh frozen and dried material. Sequencing and microsatellite fragments were analyzed for samples from 5 plant families in order to check for chloroplast and nuclear DNA quality. High-molecular weight DNA was recovered from frozen homogenates, and it was found that the quality was independent of storage time, which varied from 1 to 9 years. High-quality PCR products along with sequences and microsatellite fragments were obtained for nearly all analyzed samples. Frozen protein homogenates from previous population studies could thus be used for further phylogeographical and phylogenetic analyses using

In view of global climate change, it is important to understand the responses of tree species to climate changes in the past. Combinations of phylogeographic analysis of genetic evidence, coupled with species distribution models (SDMs), are improving our understanding on this subject. We combined SDMs and microsatellite data from populations of the entire range of Austrocedrus chilensis, a dominant mesotherm (cold-sensitive) conifer of dryland forests of the southern Andes, to test the hypothesis of long-distance postglacial migration from northern and warmer refugia at the Last Glacial Maximum (LGM). The SDM indicated suitable conditions for Austrocedrus in northern Chile (western) at the LGM and largely unsuitable conditions in Argentina (eastern). Population genetic diversity and effective population sizes within populations decreased southward along the Andes, consistent with the hypothesis of long-distance dispersal from a northern refugium. Results support the hypothesis of one (or a few) warmer (low latitude) refugia in Chile for Austrocedrus. On balance, the evidence suggests that in contrast to cold-tolerant tree taxa with the capacity to fast-track postglacial warming thanks to local refugia, cold-sensitive species might have undergone long-distance range expansion, lagging behind progressive climate change throughout the Holocene.

Despite rising global concerns over the potential impacts of non-native bumble bee (Bombus spp) introductions on native species, large-scale and long-term assessments of the consequences of such introductions are lacking. Bombus ruderatus and Bombus terrestris were sequentially introduced into Chile and later entered Argentina's Patagonian region. A large-scale survey in Patagonia reveals that, in 5 years post-arrival, the highly invasive B terrestris has become the most abundant and widespread Bombus species, and its southward spread is concurrent with the geographic retraction of the only native species, Bombus dahlbomii. Furthermore, a 20-year survey of pollinators of the endemic herb Alstroemeria aurea in northern Patagonia indicates that B ruderatus and B terrestris have replaced B dahlbomii, formerly the most abundant pollinator. Although the decline's underlying mechanisms remain unknown, the potential roles of exploitative competition and pathogen co-introduction cannot be ruled out. Given that invasive bumble bees can rapidly extirpate native congeners, further introductions should be discouraged.

In this work, we describe a method that allows the extraction of plant genomic DNA from frozen enzyme homogenates. To test if reliable DNA was recovered from allozyme extracts, we compared these results with that obtained from fresh frozen and dried material. Sequencing and microsatellite fragments were analyzed for samples from 5 plant families in order to check for chloroplast and nuclear DNA quality. High-molecular weight DNA was recovered from frozen homogenates, and it was found that the quality was independent of storage time, which varied from 1 to 9 years. High-quality PCR products along with sequences and microsatellite fragments were obtained for nearly all analyzed samples. Frozen protein homogenates from previous population studies could thus be used for further phylogeographical and phylogenetic analyses using DNA molecular tools. This simple method provides an opportunity to take advantage of stored cryopreserved samples.

The worldwide spread of diseases is considered a major threat to biodiversity and a possible driver of the decline of pollinator populations, particularly when novel species or strains of parasites emerge. Previous studies have suggested that populations of introduced European honeybee (Apis mellifera) and bumblebee species (Bombus terrestris and Bombus ruderatus) in Argentina share the neogregarine parasite Apicystis bombi with the native bumblebee (Bombus dahlbomii). In this study we investigated whether A. bombi is acting as an emergent parasite in the non-native populations. Specifically, we asked whether A. bombi, recently identified in Argentina, was introduced by European, non-native bees. Using ITS1 and ITS2 to assess the parasite's intraspecific genetic variation in bees from Argentina and Europe, we found a largely unstructured parasite population, with only 15% of the genetic variation being explained by geographic location. The most abundant haplotype in Argentina (found in all 9 specimens of non-native species) was identical to the most abundant haplotype in Europe (found in 6 out of 8 specimens). Similarly, there was no evidence of structuring by host species, with this factor explaining only 17% of the genetic variation. Interestingly, parasites in native Bombus ephippiatus from Mexico were genetically distant from the Argentine and European samples, suggesting that sufficient variability does exist in the ITS region to identify continent-level genetic structure in the parasite. Thus, the data suggest that A. bombi from Argentina and Europe share a common, relatively recent origin. Although our data did not provide information on the direction of transfer, the absence of genetic structure across space and host species suggests that A. bombi may be acting as an emergent infectious disease across bee taxa and continents.

Conservation biology can profit greatly from incorporating a phylogenetic perspective into analyses of patterns and drivers of species extinction risk. We applied such an approach to analyse patterns of bumblebee (Bombus) decline. We assembled a database representing approximately 43% of the circa 260 globally known species, which included species extinction risk assessments following the International Union fo Conservation of Nature Red List categories and criteria, and information on species traits presumably associated with bumblebee decline. We quantified the strength of phylogenetic signal in decline, range size, tongue length and parasite presence. Overall, about one-third of the assessed bumblebees are declining and declining species are not randomly distributed across the Bombus phylogeny. Susceptible species were over-represented in the subgenus Thoracobombus (approx. 64%) and under-represented in the subgenus Pyrobombus (approx. 6%). Phylogenetic logistic regressions revea...

1. The global trade of species promotes diverse human activities but also facilitates the introduction of potentially invasive species into new environments. As species ignore national boundaries, unilateral national decisions concerning species trade set the stage for transnational species invasion with significant conservation, economic and political consequences. 2. The need for a coordinated approach to species importation policies is demonstrated by the introduction of two bumblebee species into Chile for crop pollination, despite Argentina banning commercial importation of alien bumblebees based on expert opinion. The large garden bumblebee, Bombus ruderatus, was first introduced in 1982, and the buff-tailed bumblebee, Bombus terrestris, has been continually introduced since 1997 as part of the burgeoning bumblebee trade. Both species have subsequently invaded southern South America. Today, the consequences of the growth of the bumblebee trade for agricultural pollination ranks among the top 15 emerging environmental issues likely to affect global diversity. 3. Documented impacts of these invasions include the severe decline and local extinctions of the sole native Patagonian bumblebee, Bombus dahlbomii, pathogen transmission, flower damage and nectar robbing of native and cultivated plants. 4. Policy implications. The South American bumblebee invasions portrayed here should alert governments to the unintended consequences of the booming international bee trade. More broadly, this case demonstrates that one country's importation decisions can have policy implications for its neighbours without consultation. Regrettably, coordinated international measures to prevent species invasions are seldom considered in South America or elsewhere, despite existing legal frameworks. The bumblebee case and others provide stark evidence of the | 101

Although competition and predation are mechanisms more studied in biological invasions, ecologists and conservation managers have become aware of the threat imposed by the co-introduction of parasites. Parasites can be co-introduced into new areas with a non-native host, and become co-invaders when they spill over to native hosts. The copepod Lernaea cyprinacea was presumably co-introduced to Patagonia along with the common carp, Cyprinus carpio. Our aims were to compose an updated list of the hosts of L. cyprinacea and its distribution in South America, to confirm the specific identity of Patagonian specimens using molecular tools, and to enlarge the list of hosts and localities in Patagonia, by comparing infection rates between non-native and native fishes to evaluate spillover processes. Between the years 2011 and 2017, native and non-native fish species were collected in freshwater environments from Northern Patagonia in basins where common carp and non-native fishes belonging to the Brazilian biogeographic sub-region, like Characiforms, Siluriforms, and Cyprinodontiforms, have been introduced. The sampled fishes were examined under a stereoscopic microscope to search for L. cyprinacea. At present, in South America, records of L. cyprinacea parasitizing native and non-native hosts exist for Colombia, Uruguay, Brazil, Chile and Argentina, with a total of 43 host fish species. Complete sequence data from the 18S region corroborate the identity of the Patagonian parasite based on morphological characteristics. A total of 754 fish belonging to 13 species were collected and 388 copepods were recovered. Lernaea cyprinacea was registered in almost every surveyed freshwater system in Patagonia, even in places where the original host, C. carpio, was absent. The copepod was found parasitizing two native and four non-native fish species, and in general, native fishes showed higher infection values. The present study enlarges the list of localities in Patagonia. It also provides molecular confirmation of the specific identity. In summary, our results show how an alien parasite may switch host and disperse beyond the actual distribution range of the original host. This study provides an overview of the process of colonization of L. cyprinacea in Patagonia, which represents a threat to native species due to its pathogenicity.

Eusociality, a form of animal social organization involving sterile and reproductive castes, is a rare, but highly ecologically successful form of life. There are striking examples of eusocial species with populations that are ecologically dominant in their native ranges, as well as remarkably successful globally as invasive species; prominent examples include fire ants and yellowjacket wasps. At the same time, there have been startling population declines in other social insects, notably bumble bees. Here, we explore the possible role of phenotypic plasticity in invasion biology and declines of social insect species. This topic is of particular interest, because social insects exhibit extreme behavioral, developmental, physiological, and morphological plasticity. It has been suggested that this plasticity may contribute to ecological dominance in some species, but could be a liability or cost to others. In this review, we explore the relationship between phenotypic plasticity, invasion biology, and vulnerability to global change in social insects. By considering plasticity at three levels-molecular, individual, and colony-we suggest ways in which considerations of phenotypic plasticity may help in managing social insect populations.

Volcanic eruptions are large-scale natural disturbances, which can negatively affect insect fauna and the ecological interactions in which they are involved. The 2011 eruption of the volcanic complex Puyehue Cordón-Caulle (PCC) produced the deposition of 950 million tons of ash on Argentine Patagonia, creating an ash layer of varying thickness. Although experimental studies confirmed that PCC volcanic ash negatively affects survival and behavior in many insect taxa, including bees, the effects of ash deposition on the plant-pollinator interactions (PPI) of this group of insects in natural landscapes remained untested. We evaluated the effect of the gradient of increasing ash layer thickness (0-15cm) on: (1) number of wild bees visiting flowers and total bee richness in 16 raspberry fields after the eruption, (2) number of native (Bombus dahlbomii) and invasive (B. terrestris and B. ruderatus) bumble bees foraging on wild flowers in 10 sites before and after the eruption, and (3) the proportion of "triggered" flowers (i.e. papilionaceous flowers visited for first time by large bees) in 32 populations of the invasive shrub scotch broom (Cytisus scoparius), before and after the eruption. With the increase of ash deposition, we found a consistent and significant decrease in (1) the number of wild bees and total bee richness visiting raspberry flowers; (2) the number of bumble bees, particularly B. terrestris, visiting wild flowers; and (3) the proportion of triggered flowers of scotch broom. Thus, volcanic eruptions can exert a detrimental effect on bee fauna and concomitant PPI, with a potential cascade effect on the pollination service to crops, the spread of invasive bumble bees, and the pollination success of invasive plants.

Volcanic eruptions are large-scale natural disturbances, which can negatively affect insect fauna and the ecological interactions in which they are involved. The 2011 eruption of the volcanic complex Puyehue Cordón-Caulle (PCC) produced the deposition of 950 million tons of ash on Argentine Patagonia, creating an ash layer of varying thickness. Although experimental studies confirmed that PCC volcanic ash negatively affects survival and behavior in many insect taxa, including bees, the effects of ash deposition on the plant-pollinator interactions (PPI) of this group of insects in natural landscapes remained untested. We evaluated the effect of the gradient of increasing ash layer thickness (0-15cm) on: (1) number of wild bees visiting flowers and total bee richness in 16 raspberry fields after the eruption, (2) number of native (Bombus dahlbomii) and invasive (B. terrestris and B. ruderatus) bumble bees foraging on wild flowers in 10 sites before and after the eruption, and (3) the...

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Factors facilitating and hindering the invasion of exotic conifer in Isla Victoria:
Invasive species constitute a serious threat to biodiversity, producing wide-scale changes in native communities and altering
ecosystem processes. The Andean-Patagonian forests currently exhibit a wide diversity of terrestrial as well
as aquatic introduced species. Many of these introduced species possess a high invasive potential, while at the
same time have economical relevance to the region, such as sport fishing and hunting, and pine plantations.
The described situation for Patagonia offers an ideal scenario to test and generate new hypotheses about the
ecology of tree invasions. In a more practical domain, determining the impact and knowing the relationship
between native and exotic species will permit the establishment of priorities in management actions, as well as
also avoiding or mitigating the undesirable or unexpected effects that arise from eradication or control tasks.
Here, we present a synthesis of our own studies carried out to understand the factors driving the pattern of pine
invasion in the native Nothofagus/Austrocedrus forests on Isla Victoria, Nahuel Huapi National Park. Among
studied factors, we found that some of them facilitate the invasion (e.g., introduced herbivores), while others
can delay (e.g., low presence of mycorrhizae fungi, seed predation) or have neutral effects on the invasions (e.g.,
propagule pressure). These results and others currently available from this region and elsewhere allow us to
suggest management actions to prevent or hinder a major pine invasion, which should be focused on avoiding
new introductions, reducing the abundance of introduced large mammals and preserve native ecosystems with
low levels of anthropic disturbances. At the same time, we consider important to start well designed studies
to analyze the effects of these management actions.
[Keywords: biotic resistance, invasional meltdown, mycorrhizal, native forest, non-native, propagule pressure,
ungulates]