Introducción a las plantas endémicas del Perú

El endemismo es un instrumento importante para determinar y examinar los objetivos y prioridades de una estrategia para la conservación de la diversidad biológica. En este libro se trabajó con el concepto de endemismos nacionales. Se ha examinado y considerado este endemismo para diferentes niveles taxonómicos, tanto para géneros como para especies y otras categorías infra-específicas. Para la evaluación del grado de amenaza se trató las colecciones de herbario como representantes de poblaciones. Cuarenta y tres personas colaboraron y reunieron información entre 2003 y 2005. Los endemismos peruanos, al igual que en otras floras del occidente del trópico suramericano están vinculados a los Andes. Se reconoce un total de 5509 taxones restringidos al Perú y que corresponde a un 27,9% de la flora. Se categorizó aproximadamente el 76% de la flora endémica siguiendo los criterios y categorías de la UICN, versión 3.1: Las más amenazadas corresponden a las En Peligro (33%), En Peligro Critico (18%) y Vulnerables (10%). Los departamentos con mayor número de taxones endémicos corresponden a aquellos con territorio ubicado en las vertientes andinas, con amplio rango altitudinal y ecológico, siguiendo la tendencia general de la flora endémica peruana. Se espera que este trabajo abra las puertas a proyectos permanentes de monitoreo y protección de la flora endémica del país.Endemism is an important means to evaluate biological conservation goals and strategies. In this book we used the concept of national endemism. We examined different taxonomic levels, including genera, species and sub specific categories. For evaluating the degree of risk, we used herbaria specimens as representing samples of populations. Forty-three people participated between 2003 and 2005. Similar to other tropical floras of western South American, Peru's endemics are linked to the presence of the Andes. We recognize a total of 5509 endemic taxa, representing 27.9% of the total flora. We applied IUCN, version 3.1, criteria and categories to 76% of the endemic flora. The most at risk correspond to Endangered (33%), Critical Endangered (18%) and Vulnerable (10%). The departments with the highest number of endemic taxa are found among those with Andean slopes, and wide altitudinal and ecological features, similar to Peru's overall floristic trends. We hope that this book of Peru's will open the doors for monitoring and protection of Peru's endemic flora

Proteasomal degradation of sphingosine kinase 1 and inhibition of dihydroceramide desaturase by the sphingosine kinase inhibitors, SKi or ABC294640, induces growth arrest in androgen-independent LNCaP-AI prostate cancer cells

Sphingosine kinases (two isoforms termed SK1 and SK2) catalyse the formation of the bioactive lipid sphingosine 1-phosphate. We demonstrate here that the SK2 inhibitor, ABC294640 (3-(4-chlorophenyl)-adamantane-1-carboxylic acid (pyridin-4-ylmethyl)amide) or the SK1/SK2 inhibitor, SKi (2-(p-hydroxyanilino)-4-(p-chlorophenyl)thiazole)) induce the proteasomal degradation of SK1a (Mr = 42 kDa) and inhibit DNA synthesis in androgen-independent LNCaP-AI prostate cancer cells. These effects are recapitulated by the dihydroceramide desaturase (Des1) inhibitor, fenretinide. Moreover, SKi or ABC294640 reduce Des1 activity in Jurkat cells and ABC294640 induces the proteasomal degradation of Des1 (Mr = 38 kDa) in LNCaP-AI prostate cancer cells. Furthermore, SKi or ABC294640 or fenretinide increase the expression of the senescence markers, p53 and p21 in LNCaP-AI prostate cancer cells. The siRNA knockdown of SK1 or SK2 failed to increase p53 and p21 expression, but the former did reduce DNA synthesis in LNCaP-AI prostate cancer cells. Moreover, N-acetylcysteine (reactive oxygen species scavenger) blocked the SK inhibitor-induced increase in p21 and p53 expression but had no effect on the proteasomal degradation of SK1a. In addition, siRNA knockdown of Des1 increased p53 expression while a combination of Des1/SK1 siRNA increased the expression of p21. Therefore, Des1 and SK1 participate in regulating LNCaP-AI prostate cancer cell growth and this involves p53/p21-dependent and -independent pathways. Therefore, we propose targeting androgen-independent prostate cancer cells with compounds that affect Des1/SK1 to modulate both de novo and sphingolipid rheostat pathways in order to induce growth arrest

Habitat‐related error in estimating temperatures from leaf margins in a humid tropical forest

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142103/1/ajb21096.pd

Increasing biomass in Amazonian forest plots

A previous study by Phillips et al. of changes in the biomass of permanent sample plots in Amazonian forests was used to infer the presence of a regional carbon sink. However, these results generated a vigorous debate about sampling and methodological issues. Therefore we present a new analysis of biomass change in old-growth Amazonian forest plots using updated inventory data. We find that across 59 sites, the above-ground dry biomass in trees that are more than 10 cm in diameter (AGB) has increased since plot establishment by 1.22 ± 0.43 Mg per hectare per year (ha-1 yr-1), where 1 ha = 104 m2), or 0.98 ± 0.38 Mg ha-1 yr-1 if individual plot values are weighted by the number of hectare years of monitoring. This significant increase is neither confounded by spatial or temporal variation in wood specific gravity, nor dependent on the allometric equation used to estimate AGB. The conclusion is also robust to uncertainty about diameter measurements for problematic trees: for 34 plots in western Amazon forests a significant increase in AGB is found even with a conservative assumption of zero growth for all trees where diameter measurements were made using optical methods and/or growth rates needed to be estimated following fieldwork. Overall, our results suggest a slightly greater rate of net stand-level change than was reported by Phillips et al. Considering the spatial and temporal scale of sampling and associated studies showing increases in forest growth and stem turnover, the results presented here suggest that the total biomass of these plots has on average increased and that there has been a regional-scale carbon sink in old-growth Amazonian forests during the previous two decades

Delaying the International Spread of Pandemic Influenza

BACKGROUND: The recent emergence of hypervirulent subtypes of avian influenza has underlined the potentially devastating effects of pandemic influenza. Were such a virus to acquire the ability to spread efficiently between humans, control would almost certainly be hampered by limited vaccine supplies unless global spread could be substantially delayed. Moreover, the large increases that have occurred in international air travel might be expected to lead to more rapid global dissemination than in previous pandemics. METHODS AND FINDINGS: To evaluate the potential of local control measures and travel restrictions to impede global dissemination, we developed stochastic models of the international spread of influenza based on extensions of coupled epidemic transmission models. These models have been shown to be capable of accurately forecasting local and global spread of epidemic and pandemic influenza. We show that under most scenarios restrictions on air travel are likely to be of surprisingly little value in delaying epidemics, unless almost all travel ceases very soon after epidemics are detected. CONCLUSIONS: Interventions to reduce local transmission of influenza are likely to be more effective at reducing the rate of global spread and less vulnerable to implementation delays than air travel restrictions. Nevertheless, under the most plausible scenarios, achievable delays are small compared with the time needed to accumulate substantial vaccine stocks

Dra. Nállarett Marina Dávila Cardozo, 1980-2022

Nállarett, conocida en varios paı́ses de forma cariñosa como Gigi, era una gran botánica y cientı́fica, además de ser una persona dulce, empática, creativa y brillante. Ella deja un gran legado cientı́fico en sus docenas de artı́culos, sus miles de especı́menes botánicos colectados y sus descripciones de varias especies nuevas para la ciencia. Será recordada por todos los botánicos que cruzan caminos con Caraipa davilae y Compsoneura nallarettiana, ambas especies endémicas del Perú, nombradas en su honor. Nállarett era una especialista y apasionada en bosques de arena blanca, hábitats de suelos pobres dentro de la cuenca amazónica que para ella resultaron áreas fértiles para estudiar la evolución de las maravillosas plantas que los habitan. Igualmente, deja un gran legado humano por su bella forma de ser, su generosidad y su sonrisa luminosa, marcando la vida de sus amigos y colegas de forma profunda. Nállarett es y será extrañada entrañablemente por todos quienes tuvimos la suerte de conocerla. Que descanse en paz

Tree recruitment in an empty forest

To assess how the decimation of large vertebrates by hunting alters recruitment processes in a tropical forest, we compared the sapling cohorts of two structurally and compositionally similar forests in the Rio Manu floodplain in southeastern Peru. Large vertebrates were severely depleted at one site, Boca Manu (BM), whereas the other, Cocha Cashu Biological Station (CC), supported an intact fauna. At both sites we sampled small (1 m tall, ,1 cm dbh) and large (1 cm and ,10 cm dbh) saplings in the central portion of 4-ha plots within which all trees 10 cm dbh were mapped and identified. This design ensured that all conspecific adults within at least 50 m (BM) or 55 m (CC) of any sapling would have known locations. We used the Janzen-Connell model to make five predictions about the sapling cohorts at BM with respect to CC: (1) reduced overall sapling recruitment, (2) increased recruitment of species dispersed by abiotic means, (3) altered relative abundances of species, (4) prominence of large-seeded species among those showing depressed recruitment, and (5) little or no tendency for saplings to cluster closer to adults at BM. Our results affirmed each of these predictions. Interpreted at face value, the evidence suggests that few species are demographically stable at BM and that up to 28% are increasing and 72% decreasing. Loss of dispersal function allows species dispersed abiotically and by small birds and mammals to substitute for those dispersed by large birds and mammals. Although we regard these conclusions as preliminary, over the long run, the observed type of directional change in tree composition is likely to result in biodiversity loss and negative feedbacks on both the animal and plant communities. Our results suggest that the best, and perhaps only, way to prevent compositional change and probable loss of diversity in tropical tree communities is to prohibit hunting

Global Conservation Significance of Ecuador's Yasuní National Park

Margot S. Bass is with Finding Species, Matt Finer is with Save America's Forests, Clinton N. Jenkins is with Duke University and University of Maryland, Holger Kreft is with University of California San Diego, Diego F. Cisneros-Heredia is with King's College London and Universidad San Francisco de Quito, Shawn F. McCracken is with Texas State University and the TADPOLE Organization, Nigel C. A. Pitman is with Duke University, Peter H. English is with UT Austin, Kelly Swing is with Universidad San Francisco de Quito, Gorky Villa is with Finding Species, Anthony Di Fiore is with New York University, Christian C. Voigt is with Leibniz Institute for Zoo and Wildlife Research, Thomas H. Kunz is with Boston University.Background -- The threats facing Ecuador's Yasuní National Park are emblematic of those confronting the greater western Amazon, one of the world's last high-biodiversity wilderness areas. Notably, the country's second largest untapped oil reserves—called “ITT”—lie beneath an intact, remote section of the park. The conservation significance of Yasuní may weigh heavily in upcoming state-level and international decisions, including whether to develop the oil or invest in alternatives. Methodology/Principal Findings -- We conducted the first comprehensive synthesis of biodiversity data for Yasuní. Mapping amphibian, bird, mammal, and plant distributions, we found eastern Ecuador and northern Peru to be the only regions in South America where species richness centers for all four taxonomic groups overlap. This quadruple richness center has only one viable strict protected area (IUCN levels I–IV): Yasuní. The park covers just 14% of the quadruple richness center's area, whereas active or proposed oil concessions cover 79%. Using field inventory data, we compared Yasuní's local (alpha) and landscape (gamma) diversity to other sites, in the western Amazon and globally. These analyses further suggest that Yasuní is among the most biodiverse places on Earth, with apparent world richness records for amphibians, reptiles, bats, and trees. Yasuní also protects a considerable number of threatened species and regional endemics. Conclusions/Significance -- Yasuní has outstanding global conservation significance due to its extraordinary biodiversity and potential to sustain this biodiversity in the long term because of its 1) large size and wilderness character, 2) intact large-vertebrate assemblage, 3) IUCN level-II protection status in a region lacking other strict protected areas, and 4) likelihood of maintaining wet, rainforest conditions while anticipated climate change-induced drought intensifies in the eastern Amazon. However, further oil development in Yasuní jeopardizes its conservation values. These findings form the scientific basis for policy recommendations, including stopping any new oil activities and road construction in Yasuní and creating areas off-limits to large-scale development in adjacent northern Peru.The Blue Moon Fund, the Conservation, Food & Health Foundation, and the Forrest and Frances Lattner Foundation funded MF. The US National Science Foundation (Graduate Research Fellowship Program), Texas State University-Department of Biology, and TADPOLE funded SM. The US National Science Foundation, the L.S.B. Leakey Foundation, the Wenner-Gren Foundation for Anthropological Research, and Primate Conservation, Inc. funded AD. Establishment of the Tiputini Biodiversity Station supported by the US National Science Foundation–DBI-0434875 (Thomas H. Kunz, PI, with Laura M. MacLatchy, Christopher J. Schneider, and C. Kelly Swing, Co-PIs). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Biological Sciences, School o

Connections of climate change and variability to large and extreme forest fires in southeast Australia

The 2019/20 Black Summer bushfire disaster in southeast Australia was unprecedented: the extensive area of forest burnt, the radiative power of the fires, and the extraordinary number of fires that developed into extreme pyroconvective events were all unmatched in the historical record. Australia’s hottest and driest year on record, 2019, was characterised by exceptionally dry fuel loads that primed the landscape to burn when exposed to dangerous fire weather and ignition. The combination of climate variability and long-term climate trends generated the climate extremes experienced in 2019, and the compounding effects of two or more modes of climate variability in their fire-promoting phases (as occurred in 2019) has historically increased the chances of large forest fires occurring in southeast Australia. Palaeoclimate evidence also demonstrates that fire-promoting phases of tropical Pacific and Indian ocean variability are now unusually frequent compared with natural variability in preindustrial times. Indicators of forest fire danger in southeast Australia have already emerged outside of the range of historical experience, suggesting that projections made more than a decade ago that increases in climate-driven fire risk would be detectable by 2020, have indeed eventuated. The multiple climate change contributors to fire risk in southeast Australia, as well as the observed non-linear escalation of fire extent and intensity, raise the likelihood that fire events may continue to rapidly intensify in the future. Improving local and national adaptation measures while also pursuing ambitious global climate change mitigation efforts would provide the best strategy for limiting further increases in fire risk in southeast Australia

Methods to estimate aboveground wood productivity from long-term forest inventory plots

Forest inventory plots are widely used to estimate biomass carbon storage and its change over time. While there has been much debate and exploration of the analytical methods for calculating biomass, the methods used to determine rates of wood production have not been evaluated to the same degree. This affects assessment of ecosystem fluxes and may have wider implications if inventory data are used to parameterise biospheric models, or scaled to large areas in assessments of carbon sequestration. Here we use a dataset of 35 long-term Amazonian forest inventory plots to test different methods of calculating wood production rates. These address potential biases associated with three issues that routinely impact the interpretation of tree measurement data: (1) changes in the point of measurement (POM) of stem diameter as trees grow over time; (2) unequal length of time between censuses; and (3) the treatment of trees that pass the minimum diameter threshold (“recruits”). We derive corrections that control for changing POM height, that account for the unobserved growth of trees that die within census intervals, and that explore different assumptions regarding the growth of recruits during the previous census interval. For our dataset we find that annual aboveground coarse wood production (AGWP; in Mg ha−1 year−1 of dry matter) is underestimated on average by 9.2% if corrections are not made to control for changes in POM height. Failure to control for the length of sampling intervals results in a mean underestimation of 2.7% in annual AGWP in our plots for a mean interval length of 3.6 years. Different methods for treating recruits result in mean differences of up to 8.1% in AGWP. In general, the greater the length of time a plot is sampled for and the greater the time elapsed between censuses, the greater the tendency to underestimate wood production. We recommend that POM changes, census interval length, and the contribution of recruits should all be accounted for when estimating productivity rates, and suggest methods for doing this.European UnionUK Natural Environment Research CouncilGordon and Betty Moore FoundationCASE sponsorship from UNEP-WCMCRoyal Society University Research FellowshipERC Advanced Grant “Tropical Forests in the Changing Earth System”Royal Society Wolfson Research Merit Awar