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Matthias Baumann, Ignacio Gasparri, María Piquer-Rodríguez, Gregorio Gavier Pizarro, Patrick Griffiths, Patrick Hostert, Tobias Kuemmerle
Carbon emissions from land-use changes in tropical dry forest systems are poorly understood, although they are likely globally significant. The South American Chaco has recently emerged as a hot spot of agricultural expansion and intensification, as cattle ranching and soybean cultivation expand into forests, and as soybean cultivation replaces grazing lands. Still, our knowledge of the rates and spatial patterns of these land-use changes and how they affected carbon emissions remains partial. We used the Landsat satellite image archive to reconstruct land-use change over the past 30 years and applied a carbon bookkeeping model to quantify how these changes affected carbon budgets...
October 26, 2016: Global Change Biology
Michael A Mole, Shaun Rodrigues DÁraujo, Rudi J van Aarde, Duncan Mitchell, Andrea Fuller
Most of southern Africa's elephants inhabit environments where environmental temperatures exceed body temperature, but we do not know how elephants respond to such environments. We evaluated the relationships between apparent thermoregulatory behaviour and environmental, skin and core temperatures for tame savanna elephants (Loxodonta africana) that were free-ranging in the hot parts of the day, in their natural environment. Environmental temperature dictated elephant behaviour within a day, with potential consequences for fine-scale habitat selection, space use and foraging...
2016: Conservation Physiology
Kari E Veblen, Lauren M Porensky, Corinna Riginos, Truman P Young
The widespread replacement of wild ungulate herbivores by domestic livestock in African savannas is composed of two interrelated phenomena: (1) loss or reduction in numbers of individual wildlife species or guilds and (2) addition of livestock to the system. Each can have important implications for plant community dynamics. Yet very few studies have experimentally addressed the individual, combined, and potentially interactive effects of wild vs. domestic herbivore species on herbaceous plant communities within a single system...
September 2016: Ecological Applications: a Publication of the Ecological Society of America
Scott Schlossberg, Michael J Chase, Curtice R Griffin
Accurate counts of animals are critical for prioritizing conservation efforts. Past research, however, suggests that observers on aerial surveys may fail to detect all individuals of the target species present in the survey area. Such errors could bias population estimates low and confound trend estimation. We used two approaches to assess the accuracy of aerial surveys for African savanna elephants (Loxodonta africana) in northern Botswana. First, we used double-observer sampling, in which two observers make observations on the same herds, to estimate detectability of elephants and determine what variables affect it...
2016: PloS One
Humberto M Barbosa, Jailson N DO Nascimento, Thiago A S Araújo, Filipe S Duarte, Ulysses P Albuquerque, Jeymesson R C Vieira, Edson R B DE Santana, Ricardo Yara, Cláudia S A Lima, Dayane A Gomes, Eduardo C Lira
Spondias tuberosa Arruda, popularly named as umbu, is native from savanna-like vegetation and widely used for medicinal purposes, however, the toxicological profile is not available yet. This study evaluated the phytochemical profile and acute toxicity and citoxicity of Ethanolic Extract of Spondias tuberosa Arruda Bark (EEStb) in hematological, biochemical and histopathological parameters. Female Wistar rats were divided into: control (C) and animal treated single doses of 300mg/Kg (EEStb300) or 2.000mg/kg body weight (ESStb2...
October 10, 2016: Anais da Academia Brasileira de Ciências
Victor K Muposhi, Edson Gandiwa, Paul Bartels, Stanley M Makuza, Tinaapi H Madiri
The selective nature of trophy hunting may cause changes in desirable phenotypic traits in harvested species. A decline in trophy size of preferred species may reduce hunting destination competitiveness thus compromising the sustainability of trophy hunting as a conservation tool. We explored the trophy quality and trends in harvesting patterns (i.e., 2004-2015) of Cape buffalo (Syncerus caffer), African elephant (Loxodonta africana), greater kudu (Tragelaphus strepsiceros) and sable (Hippotragus niger) in Matetsi Safari Area, northwest Zimbabwe...
2016: PloS One
Andrew L Skowno, Mark W Thompson, Jens Hiestermann, Brad Ripley, Adam G West, William J Bond
Increases in woody plant cover in savanna-grassland environments have been reported on globally for over 50 years and are generally perceived as a threat to rangeland productivity and biodiversity. Despite this few attempts have been made to estimate the extent of woodland increase at a national scale, principally due to technical constraints such as availability of appropriate remote sensing products. In this study we aim to measure the extent to which woodlands have replaced grasslands in South Africa's grassy biomes...
October 12, 2016: Global Change Biology
Marcelo Pedrosa Gomes, Fernanda Vieira da Silva Cruz, Elisa Monteze Bicalho, Felipe Viègas Borges, Marcia Bacelar Fonseca, Philippe Juneau, Queila Souza Garcia
Glyphosate-formulations are widely used in the Brazilian Cerrado (neotropical savanna) with little or no control, threatening population of the endangered species Dimorphandra wilsonii. We investigated the toxicity of different concentrations (0, 5, 25 and 50 mg l(-1)) of glyphosate acid and one of its formulations (Roundup(®)) on seed germination in D. wilsonii. Glyphosate acid and Roundup drastically decreased seed germination by decreasing seed respiration rates. The activation of antioxidant enzymes, ascorbate peroxidase and catalase assure no hydrogen peroxide accumulation in exposed seeds...
October 7, 2016: Environmental Pollution
Xenia Freilich, José D Anadón, Jolanta Bukala, Ordaliza Calderon, Ronveer Chakraborty, Stéphane Boissinot
BACKGROUND: The Ethiopian highlands are a biodiversity hotspot, split by the Great Rift Valley into two distinct systems of plateaus and mountains. The Rift Valley is currently hot and dry and acts as a barrier to gene flow for highland-adapted species. It is however unlikely that the conditions in the Rift were inhospitable to highland species during the entire Pleistocene. To assess the significance of the Ethiopian Rift as a biogeographic barrier as well as the impact Pleistocene climatic changes have had on the evolution of Ethiopian organisms, we performed phylogeographic analyses and developed present and past niche models on seven anuran species with different elevational and ecological preferences...
October 10, 2016: BMC Evolutionary Biology
Karina Banda-R, Alfonso Delgado-Salinas, Kyle G Dexter, Reynaldo Linares-Palomino, Ary Oliveira-Filho, Darién Prado, Martin Pullan, Catalina Quintana, Ricarda Riina, Gina M Rodríguez M, Julia Weintritt, Pedro Acevedo-Rodríguez, Juan Adarve, Esteban Álvarez, Anairamiz Aranguren B, Julián Camilo Arteaga, Gerardo Aymard, Alejandro Castaño, Natalia Ceballos-Mago, Álvaro Cogollo, Hermes Cuadros, Freddy Delgado, Wilson Devia, Hilda Dueñas, Laurie Fajardo, Ángel Fernández, Miller Ángel Fernández, Janet Franklin, Ethan H Freid, Luciano A Galetti, Reina Gonto, Roy González-M, Roger Graveson, Eileen H Helmer, Álvaro Idárraga, René López, Humfredo Marcano-Vega, Olga G Martínez, Hernán M Maturo, Morag McDonald, Kurt McLaren, Omar Melo, Francisco Mijares, Virginia Mogni, Diego Molina, Natalia Del Pilar Moreno, Jafet M Nassar, Danilo M Neves, Luis J Oakley, Michael Oatham, Alma Rosa Olvera-Luna, Flávia F Pezzini, Orlando Joel Reyes Dominguez, María Elvira Ríos, Orlando Rivera, Nelly Rodríguez, Alicia Rojas, Tiina Särkinen, Roberto Sánchez, Melvin Smith, Carlos Vargas, Boris Villanueva, R Toby Pennington
Seasonally dry tropical forests are distributed across Latin America and the Caribbean and are highly threatened, with less than 10% of their original extent remaining in many countries. Using 835 inventories covering 4660 species of woody plants, we show marked floristic turnover among inventories and regions, which may be higher than in other neotropical biomes, such as savanna. Such high floristic turnover indicates that numerous conservation areas across many countries will be needed to protect the full diversity of tropical dry forests...
September 23, 2016: Science
R M Hernández-Hernández, A Roldán, F Caravaca, G Rodriguez-Caballero, M P Torres, F T Maestre, M M Alguacil
Knowledge of the arbuscular mycorrhizal fungal assemblages in the Trachypogon savanna ecosystems is very important to a better understanding of the ecological processes mediated by this soil microbial group that affects multiple ecosystem functions. Considering the hypothesis that the biocrusts can be linked to vegetation through the arbuscular fungi mycelial network, the objectives proposed in this study were to determine (i) whether there are arbuscular mycorrhizal fungi (AMF) in the biocrusts (ii) whether arbuscular mycorrhizal fungal assemblages are linked to the Trachypogon patches, and (iii) whether the composition of the assemblages is related to soil properties affected by microbiological activity...
September 30, 2016: Science of the Total Environment
Bruce W Clegg, Timothy G O'Connor
As a foundation for understanding the diet of African savanna elephants (Loxodonta africana), adult bulls and cows were observed over an annual cycle to determine whether harvesting (Pt ), chewing (Ct ) and handling times (Ht ) differed across food types and harvesting methods (handling time is defined as the time to harvest, chew and swallow a trunkload of food). Bulls and cows were observed 105 and 26 times, respectively (94 and 26 individuals), with a total of 64 h of feeding recorded across 32 vegetation types...
2016: PeerJ
Rita de Cassia Bianchi, Natalie Olifiers, Matthew E Gompper, Guilherme Mourão
We investigated the home range size, habitat selection, as well as the spatial and activity overlap, of four mid-sized carnivore species in the Central Pantanal, Mato Grosso do Sul, Brazil. From December 2005 to September 2008, seven crab-eating foxes Cerdocyon thous, seven brown-nosed coatis Nasua nasua, and six ocelots Leopardus pardalis were radio-collared and monitored. Camera trap data on these species were also collected for the crab-eating raccoon Procyon cancrivorus. We hypothesized that there would be large niche differentiation in preferred habitat-type or active period between generalist species with similar diet, and higher similarity in habitat-type or activity time between the generalist species (crab-eating foxes and coatis) and the more specialized ocelot...
2016: PloS One
Mauricio N Godoi, Edivaldo O DE Souza
Different vegetation types are distributed in mountains according to altitude, topography and soil. The composition and structure of bird communities in these areas can change in relation to the vegetation gradient, with particular communities occupying each habitat type. In this study we present the changes in composition, species richness and bird abundance over the gradient of forests, savannas and altitudinal grasslands of Maciço do Urucum, a mountainous region located in the Chiquitano Dry Forests domain in western Brazil...
September 22, 2016: Anais da Academia Brasileira de Ciências
Reginaldo Brito da Costa, Jeane Cabral da Silva, Leandro Skowronski, Michel Constantino, Hemerson Pistori, Jannaína Velasques da Costa Pinto
Assessing the parental genetic differences and their subsequent prediction of progeny performance is an important first step to assure the efficiency of any breeding program. In this study, we estimate the genetic divergence in Eucalyptus camaldulensis based on the morphological traits of 132 progenies grown in a savanna biome. Thus, a field experiment was performed using a randomized block design and five replications to compare divergences in total height, commercial height, diameter at breast height, stem form and survival rate at 48 months...
2016: PloS One
Victor K Muposhi, Edson Gandiwa, Abel Chemura, Paul Bartels, Stanley M Makuza, Tinaapi H Madiri
An understanding of the habitat selection patterns by wild herbivores is critical for adaptive management, particularly towards ecosystem management and wildlife conservation in semi arid savanna ecosystems. We tested the following predictions: (i) surface water availability, habitat quality and human presence have a strong influence on the spatial distribution of wild herbivores in the dry season, (ii) habitat suitability for large herbivores would be higher compared to medium-sized herbivores in the dry season, and (iii) spatial extent of suitable habitats for wild herbivores will be different between years, i...
2016: PloS One
Breda M Zimkus, Lucinda P Lawson, Michael Barej, Christopher D Barratt, Alan Channing, Katrina M Dash, J Maximilian Dehling, Louis Du Preez, Philip-Sebastian Gehring, Eli Greenbaum, Václav Gvoždík, James Harvey, Jos Kielgast, Chifundera Kusamba, Zoltán T Nagy, Maciej Pabijan, Johannes Penner, Mark-Oliver Rödel, Miguel Vences, Stefan Lötters
The Mascarene ridged frog, Ptychadena mascareniensis, is a species complex that includes numerous lineages occurring mostly in humid savannas and open forests of mainland Africa, Madagascar, the Seychelles, and the Mascarene Islands. Sampling across this broad distribution presents an opportunity to examine the genetic differentiation within this complex and to investigate how the evolution of bioclimatic niches may have shaped current biogeographic patterns. Using model-based phylogenetic methods and molecular-clock dating, we constructed a time-calibrated molecular phylogenetic hypothesis for the group based on mitochondrial 16S rRNA and cytochrome b (cytb) genes and the nuclear RAG1 gene from 173 individuals...
September 21, 2016: Molecular Phylogenetics and Evolution
Susan Schwinn, Robin McKay, Shirley Dinkel, Bobbe Mansfield, Brooke Faria Da Cunha, Savanna Cummins, Krystal Brunin
PURPOSE: The purpose of this quality improvement project was to evaluate hypertension (HTN) management in patients 80 years of age and older who reside in a large, long-term care (LTC) facility. DATA SOURCE: A retrospective chart audit was conducted on 75 charts of patients 80 years of age and older and who had a diagnosis of HTN. Using the 2011 American College of Cardiology Foundation/American Heart Association (ACCF/AHA) Expert Consensus Document on Management of Hypertension in the Elderly as a guide, blood pressure readings, significant comorbidities, and antihypertensive medication utilization were analyzed...
September 23, 2016: Journal of the American Association of Nurse Practitioners
V Yatat, P Couteron, J J Tewa, S Bowong, Y Dumont
Fires and mean annual rainfall are major factors that regulate woody and grassy biomasses in savanna ecosystems. Within the savanna biome, conditions of long-lasting coexistence of trees and grasses have been often studied using continuous-time modelling of tree-grass competition. In these studies, fire is a time-continuous forcing while the relationship between woody plant size and fire-sensitivity is not systematically considered. In this paper, we propose a new mathematical framework to model tree-grass interactions that takes into account both the impulsive nature of fire occurrence and size-dependent fire sensitivity (via two classes of woody plants)...
September 22, 2016: Journal of Mathematical Biology
Yasuko Ishida, Peter J Van Coeverden de Groot, Keith E A Leggett, Andrea S Putnam, Virginia E Fox, Jesse Lai, Peter T Boag, Nicholas J Georgiadis, Alfred L Roca
Locally isolated populations in marginal habitats may be genetically distinctive and of heightened conservation concern. Elephants inhabiting the Namib Desert have been reported to show distinctive behavioral and phenotypic adaptations in that severely arid environment. The genetic distinctiveness of Namibian desert elephants relative to other African savanna elephant (Loxodonta africana) populations has not been established. To investigate the genetic structure of elephants in Namibia, we determined the mitochondrial (mt) DNA control region sequences and genotyped 17 microsatellite loci in desert elephants (n = 8) from the Hoanib River catchment and the Hoarusib River catchment...
September 2016: Ecology and Evolution
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