The subtribe Espeletiinae (Asteraceae), endemic to the high-elevations in the Northern Andes, exhibits an exceptional diversity of species, growth-forms, and reproductive strategies. This complex of ...140 species includes large trees, dichotomous trees, shrubs and the extraordinary giant caulescent rosettes, considered as a classic example of adaptation in tropical high-elevation ecosystems. The subtribe has also long been recognized as a prominent case of adaptive radiation, but the understanding of its evolution has been hampered by a lack of phylogenetic resolution. Herein, we produce the first fully resolved phylogeny of all morphological groups of Espeletiinae, using whole plastomes and about a million nuclear nucleotides obtained with an original de novo assembly procedure without reference genome, and analyzed with traditional and coalescent-based approaches that consider the possible impact of incomplete lineage sorting and hybridization on phylogenetic inference. We show that the diversification of Espeletiinae started from a rosette ancestor about 2.3 Ma, after the final uplift of the Northern Andes. This was followed by two independent radiations in the Colombian and Venezuelan Andes, with a few trans-cordilleran dispersal events among low-elevation tree lineages but none among high-elevation rosettes. We demonstrate complex scenarios of morphological change in Espeletiinae, usually implying the convergent evolution of growth-forms with frequent loss/gains of various traits. For instance, caulescent rosettes evolved independently in both countries, likely as convergent adaptations to life in tropical high-elevation habitats. Tree growth-forms evolved independently three times from the repeated colonization of lower elevations by high-elevation rosette ancestors. The rate of morphological diversification increased during the early phase of the radiation, after which it decreased steadily towards the present. On the other hand, the rate of species diversification in the best-sampled Venezuelan radiation was on average very high (3.1 spp/My), with significant rate variation among growth-forms (much higher in polycarpic caulescent rosettes). Our results point out a scenario where both adaptive morphological evolution and geographical isolation due to Pleistocene climatic oscillations triggered an exceptionally rapid radiation for a continental plant group.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A novel analytical approach to classify breeding systems in Angiosperms combining statistical and conceptual criteria is proposed, which will allow to describe and compare available mating system ...data in an unified form. Four breeding system indexes (BSI) were combined: Index of Agamospermy, Index of Spontaneous Self-Pollination (ISSP), Index of Self-Fertility (ISF), and Index of Self-incompatibility. Their values, ranging from 0 to ∞, were analyzed using t tests to discriminate experimental breeding index values from 0 and 1.0. For each index, five discrete categories were described. The composite of the four BSI assigned to a species represents an integrated characterization of its reproductive system. A magnitude measure (M) describes the strength of each BSI assigned to a species. Indexes of inbreeding and outbreeding depression were also examined for each species. Published data from 1908 taxa were used to determine composite breeding systems. Frequencies of breeding index categories across the four BSI for the entire data set were determined. Non-spontaneous self-pollinating and xenogamous species were the most frequent categories observed for ISSP and ISF indexes, respectively. The largest group of species examined was partially self-incompatible. Actual number of composite breeding systems inferred based on our analysis represents a small fraction (8.9 %) of all mathematically possible ones. Similarly, the observed combinations between results obtained from the four pollination tests and estimates of natural reproductive efficiency were only 22.1 % of all mathematically possible combinations. Within Angiosperms, there is a marked trend toward evolution of partial self-incompatibility with significant inbreeding depression.
Bats use olfactory signals to provide information of species and individual identity and quality. Males of two species of long-nosed bats,
Leptonycteris curasoae
and
L. yerbabuenae
, display an ...odoriferous dorsal patch during the mating season that is involved in mate choice. The dorsal patch is documented to serve as an indicator of male quality; for instance, males with dorsal patch present larger testes and lower ectoparasite loads. We evaluated the role of the dorsal patch in males of
L. curasoae
and
L. yerbabuenae
as an indicator of inflammatory response 6 and 12 h after being injected with phytohemagglutinin (PHA). We found that the inflammatory response of males of both species was not different between reproductively active bats with or without dorsal patch 6 h after PHA injection, but the response was higher in bats with dorsal patch 12 h after the injection. Our study adds to the evidence that the dorsal patch exhibited by males of long-nosed bats indicates their immune quality for mating females. Further work including other branches of the immune system and the potential role of microbiota in the strength of the inflammatory response is warranted.
Vegetation of tropical dry ecosystems is represented by patches of plants with different photosynthetic pathways. We used C and N stable isotope mixing models to assess the relative importance of CAM ...and C3 vegetation as direct or indirect sources of food for birds in a Neotropical semiarid zone. We analyzed tissues from 26 bird species encompassing a broad array of feeding habits in the dry and rainy seasons. Although CAM plants are important elements of our study site, their use as food was mainly restricted to some plant‐eating and omnivorous bird species. “Intermediate” or “High” dependence on CAM food was observed in only 7 species: three frugivores, one nectarivore, one granivore, and two omnivores. Instead, C3‐derived food sustained most of the bird species studied, even some for which dependence on CAM‐derived food was reported in studies using other methodological approaches. Consumption of C3 insects extended to the entire assemblage of birds, including plant‐eating species. Our findings highlight the importance of maintaining vegetation heterogeneity in arid zones for animal communities and the need to provide increasing protection measures to woody C3 species, as their local demand for firewood is rapidly increasing.
in Spanish is available with online material.
Resumen
Documentamos diferenças arquiteturais entre espécies arbóreas tropicais de subosque, coexistentes, que indicam estratégias distintas: redução de auto‐sombreamento e custos de suporte ou maximização do forrageio por luz. Houve mudança no “ranking” específico de crescimento conforme a luminosidade, sugerindo que diferenças arquiteturais facilitam a coexistência de espécies com habitats verticais similares.
Examinar como ambos padrões de distribuições: climáticos e de espécies, se correlacionam com a morfologia foliar pode oferecer informações sobre padrões ecológicos e evolutivos, que direcionam a seleção adaptativa de formas e funções de folha. Os Drip‐tips são uma característica comum de folhas de árvores da floresta tropical; eles são considerados como uma adaptação que auxilia no dessecamento das folhas e maximiza a fotossíntese nas áreas com clima de alta precipitação. Nós testamos se esse padrão macroecológico ocorre até mesmo através de gradientes de precipitação em uma região que não é de floresta tropical ‐ as savanas das florestas do Brasil conhecidas como Cerrado, e comparamos nossos resultados com estudos prévios da Amazônia. Os Drip‐tips eram, como esperado, menos comuns em geral no Cerrado mais seco do que na Amazônia. Além disso, dentro do Cerrado os drip‐tips eram mais prevalentes nas áreas com maior pluviosidade, assim como nas regiões de Cerrado mais próximas à Amazônia. Além disso, as espécies que ocorreram através de ambos Cerrado e Amazônia tiveram drip‐tips mais frequentes do que as espécies que foram encontradas somente no Cerrado. Essas descobertas corroboram com as hipóteses de que drip‐tips são adaptativos e que ou o custo de contenção de drip‐tips é baixo ou em regiões mais secas eles tem outros benefícios.
Tropical dry forests (TDFs) are highly endangered tropical ecosystems being replaced by a complex mosaic of patches of different successional stages, agricultural fields and pasturelands. In this ...context, it is urgent to understand how taxa playing critical ecosystem roles respond to habitat modification. Because Phyllostomid bats provide important ecosystem services (e.g. facilitate gene flow among plant populations and promote forest regeneration), in this study we aimed to identify potential patterns on their response to TDF transformation in sites representing four different successional stages (initial, early, intermediate and late) in three Neotropical regions: México, Venezuela and Brazil. We evaluated bat occurrence at the species, ensemble (abundance) and assemblage level (species richness and composition, guild composition). We also evaluated how bat occurrence was modulated by the marked seasonality of TDFs. In general, we found high seasonal and regional specificities in phyllostomid occurrence, driven by specificities at species and guild levels. For example, highest frugivore abundance occurred in the early stage of the moistest TDF, while highest nectarivore abundance occurred in the same stage of the driest TDF. The high regional specificity of phyllostomid responses could arise from: (1) the distinctive environmental conditions of each region, (2) the specific behavior and ecological requirements of the regional bat species, (3) the composition, structure and phenological patterns of plant assemblages in the different stages, and (4) the regional landscape composition and configuration. We conclude that, in tropical seasonal environments, it is imperative to perform long-term studies considering seasonal variations in environmental conditions and plant phenology, as well as the role of landscape attributes. This approach will allow us to identify potential patterns in bat responses to habitat modification, which constitute an invaluable tool for not only bat biodiversity conservation but also for the conservation of the key ecological processes they provide.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
La experiencia RELCOM Burneo, Santiago F.; Barquez, Rubén M.; Aguirre, Luis F. ...
Mammalogy notes = Notas mastozoológicas,
11/2022, Letnik:
8, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Presentamos la experiencia de la Red Latinoamericana para la Conservación de los Murciélagos (RELCOM) y los frutos que ha cosechado. RELCOM nace 15 años, en Mérida, Yucatán, México, donde un grupo de ...especialistas de murciélagos y líderes en sus países, se reunieron en un congreso internacional. Hoy la RELCOM reúne a 23 Programas para la Conservación de los Murciélagos de 25 países de Latinoamérica y el Caribe. El proyecto áreas importantes para la conservación de los murciélagos (AICOMs) y sitios importantes para la conservación de los murciélagos (SICOMs) surge en 2011 y hoy cuenta con mas de 200 áreas en 21 países.
It has long been recognized that plant invasions may alter carbon (C) and nitrogen (N) cycles, but the direction and magnitude of such alterations have been rarely quantified. In this study, we ...quantified the effects caused by the invasion of a noxious exotic plant, Kalanchoe daigremontiana (Crassulaceae), on C and N mineralization and enzymatic and microbial activities in the soil of a semiarid locality in Venezuela. We compared soil parameters associated with these processes (C and N mineralization time and the cumulative values, fluorescein diacetate hydrolytic activity, and activities of dehydrogenase, β-glucosidase, glucosaminidase, and urease) between invaded and adjacent non-invaded sites. In addition, correlations among these parameters and the soil physical-chemical properties were also examined to determine if a positive feedback exists between nutrient availability and K. daigremontiana invasion. Overall, our results showed that C mineralization and transformation of organic compounds to NH4+ were favored at sites colonized by K. daigremontiana. With this species, we found the highest cumulative amounts of NH4+-N and C and the lowest mineralization time. These results could be explained by higher activities of urease and glucosaminidase in soils under the influence of K. daigremontiana. In addition, higher amounts of organic matter and moisture content in invaded soils might favor C and N mineralization. In conclusion, invasion of Neotropical semiarid zones by K. daigremontiana may influence the chemical and biological properties of the soils covered by this species, increasing nutrient bioavailability, which, in time, can facilitate the invasion process.
Kalanchoe daigremontiana and Stapelia gigantea are two succulent invasive species with potential impacts on recruitment of native vegetation in a protected area of importance for conservation of arid ...environments in northern South America. We hypothesized that while K. daigremontiana has the potential for inhibiting recruitment of native plants through allelopathic effects, S. gigantea could facilitate recruitment of nurse-dependent native taxa. To explore these contrasting impacts, we designed a comparative study and a transplant experiment. Density of native seedlings and species richness were significantly lower in patches invaded by K. daigremontiana when compared to patches with native vegetation or invaded by S. gigantea, suggesting that native-seedling recruitment is negatively affected by K. daigremontiana and not affected or facilitated by S. gigantea. The experiment did not generate results concordant with those obtained in the comparative study. Seedlings' recruitment of two selected native species was facilitated by presence of nurse-plants (exotics and natives); however, the magnitude of this effect varied according to the type of nurse-plant, susceptibility to herbivory, and herbivory level. We identify K. daigremontiana as the invasive with top need for management actions, because it has the potential to alter composition and physiognomy of native-plant communities in tropical arid environments.
•Invasive succulent plants alter the recruitment of native vegetation.•Kalanchoe daigremontiana has the potential for inhibiting native—plant recruitment.•Stapelia gigantea can facilitate recruitment of nurse-dependent native taxa.
Abstract Trypanosoma evansi is a mammal generalist protozoon which causes negative effects on health and productivity in bovine and equine herds in South America, Europe, Asia and Africa. By ...molecular methods, we screened the presence of that parasite together with other trypanosome species in 105 bats of 10 species collected in arid zones of northern Venezuela. The first molecular approach was fluorescent fragment length barcoding (FFLB), which relies on amplification of relative small regions of rRNA genes (four loci) and fluorescence detection. By FFLB, 17 samples showed patterns of possible trypanosomatid infections. These samples were used to test presence of trypanosomes by PCR using the following DNA markers: V7–V8 SSU rRNA, gGAPDH and kDNA minicircle regions. Only in one individual of the nectar-feeding bat, Leptonycteris curasoae , we were able to amplify 1000 bp of the trypanosome kDNA minicircle. That PCR product was sequenced and the parasite species was determined by NCBI-BLAST and phylogenetic analysis. Both analyses showed that the minicircle sequence corresponds to Trypanosoma evansi . The phylogenetic analysis of the sequence obtained in this study clustered with a T. evansi sequence obtained in a Venezuelan capybara, Hydrochoerus hydrochaeris , and distant of others two T. evansi sequences obtained in a Colombian capybara and horse. This result supports the hypothesis of multiple origins of T. evansi in South America.
Agave inaequidens and A. hookeri are anciently used species for producing the fermented beverage 'pulque', food and fiber in central Mexico. A. inaequidens is wild and cultivated and A. hookeri only ...cultivated, A. inaequidens being its putative wild relative. We analysed purposes and mechanisms of artificial selection and phenotypic divergences between wild and managed populations of A. inaequidens and between them and A. hookeri, hypothesizing phenotypic divergence between wild and domesticated populations of A. inaequidens in characters associated to domestication, and that A. hookeri would be phenotypically similar to cultivated A. inaequidens.
We studied five wild and five cultivated populations of A. inaequidens, and three cultivated populations of A. hookeri. We interviewed agave managers documenting mechanisms of artificial selection, and measured 25 morphological characters. Morphological similarity and differentiation among plants and populations were analysed through multivariate methods and ANOVAs.
People recognized 2-8 variants of A. inaequidens; for cultivation they select young plants collected in wild areas recognized as producing the best quality mescal agaves. Also, they collect seeds of the largest and most vigorous plants, sowing seeds in plant beds and then transplanting the most vigorous plantlets into plantations. Multivariate methods classified separately the wild and cultivated populations of A. inaequidens and these from A. hookeri, mainly because of characters related with plant and teeth size. The cultivated plants of A. inaequidens are significantly bigger with larger teeth than wild plants. A. hookeri are also significatly bigger plants with larger leaves but lower teeth density and size than A. inaequidens. Some cultivated plants of A. inaequidens were classified as A. hookeri, and nearly 10% of A. hookeri as cultivated A. inaequidens. Wild and cultivated populations of A. inaequidens differed in 13 characters, whereas A. hookeri differed in 23 characters with wild populations and only in 6 characters with cultivated populations of A. inaequidens.
Divergence between wild and cultivated populations of A. inaequidens reflect artificial selection. A. hookeri is similar to the cultivated A. inaequidens, which supports the hypothesis that A. hookeri could be the extreme of a domestication gradient of a species complex.
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