Search

Made available in DSpace on 2022-04-28T19:46:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Fire and herbivory are major drivers in tropical savanna ecosystems and they selected a flora composed of species able to cope with recurrent aboveground biomass removal. Renewal of the herbaceous stratum is made possible by resprouting, mostly through a belowground bud bank. Evaluating the impacts of disturbances on the bud bank can assist in predicting post-disturbance responses and system resilience. In a semi-arid savanna, we aimed to verify whether lower fire frequency, fire and herbivory exclusion could affect belowground bud bank and organs diversity and consequently, the resprouting potential. Lower fire frequency or suppression and absence of herbivory were expected to reduce the bud bank density, which was confirmed by our results. If the fire is suppressed or fire frequency is reduced, the total, graminoid and the shrub bud bank decreased, whereas herbivory exclusion resulted in total and a forb bud bank of lower densities. Belowground buds were identified in non-woody and woody rhizomes, stolons, root crowns, and bulbs or corms. Despite having bud banks of lower density, disturbance exclusion promoted belowground biomass accumulation. Our results indicated the importance of maintaining the endogenous disturbances to the preservation of the belowground community and regeneration strategy, guaranteeing resilience in semi-arid savanna communities. Instituto de Biociências Universidade Estadual Paulista (UNESP) Unit for Environmental Sciences and Management North-West University Instituto de Biociências Universidade Estadual Paulista (UNESP)

Projected increases in the frequency and severity of drought events are expected to impose changes in the ecology of native forb communities in semi-arid ecosystems. We examined the state of forb communities during, and directly after an extreme drought event across two contrasting land-use types, which included a protected area (high diversity of free roaming wild herbivores) and communal rangeland (long history of intensive cattle grazing) in a semi-arid Lowveld savanna of the Gazankulu area, South Africa. Forb floristic data were collected towards the end of the drought and repeated after the drought release a few months later. Forb community composition was significantly different among land-use types. Community changes were not induced by annual forb emergence alone, but through species-specific dominance shifts, which differed among land-use types. Forb richness, diversity and biomass were equally low at both land-use types and increased significantly after the drought release, although the magnitude of response was much stronger in the protected area, whereas drought contributed to a directional change in the protected area with a complete post-drought turnover in both annual and perennial forb species, much less variability was observed in the communal rangeland, which may suggest long-term effects imposed by land-use history.

A presente pesquisa teve como objetivo a aplicacao do po da semente da planta denominada Moringa Oleifera Lam, a partir do processo de maceracao dessa semente, juntamente com a radiacao solar, no tratamento de agua utilizada para o consumo humano. Neste trabalho foram coletadas amostras de agua em diferentes pocos artesianos, localizados no municipio do Cabo de Santo Agostinho/PE, situados nas praias de Enseada dos Corais e Gaibu, bem como, no Bairro de Ponte dos Carvalhos, sendo realizadas analises fisico-quimicas e microbiologicas, para determinar o poco que seria realizado esse tratamento previo, monitorando, principalmente, a sua eficiencia na remocao bacteriana. Dois tipos de planejamentos experimentais foram realizados, o primeiro usando um fatorial completo 2 3 , com 2 niveis e 3 fatores, a fim de avaliar a influencia dos parâmetros: Concentracao do po da semente da Moringa Oleifera (C M ) em (g.L -1 ), o tempo de exposicao da radiacao solar (t) em (h) e o potencial Hidrogenionico (pH), no que se refere a variavel resposta para DBO (Demanda Biologica de Oxigenio) e DQO (Demanda Quimica de Oxigenio). Assim como, coliformes totais e coliformes termotolerantes, em especial a Escherichia coli. Nos demais ensaios, o planejamento fatorial completo 2 2 , com dois niveis e dois fatores, mostrou duas variaveis independentes: 1) a (C M ) em (g.L -1 ) e o (pH) e 2) o (t) em (h) e o (pH). As variaveis dependentes para as analises fisico-quimicas tambem foram: DBO (mg.L -1 ) e DQO (mg.L -1 ). Assim como, para as analises microbiologicas foram: coliforme totais (UFC.mL -1 ) e coliformes termotolerantes ( E. coli ) (UFC.mL -1 ). O ensaio utilizando os fatores: t=10 h, C M = 2 g.L -1 e pH= 6apresentou menor valor de DQO igual a 7,3 e DBO igual a 2,8 mg.L -1 e mostrou ser o melhor, embora ainda precisa ser mais reduzido esses valores e analisado para o uso apenas com a radiacao solar. Entretanto, o ensaio utilizando os fatores: t=4 h e pH= 6, fixando C M = 2 g.L -1 ,do planejamento 2 2 , foi o que apresentou ser o mais satisfatorio para essa etapa do planejamento, com valores iguais a zero, tanto para coliformes totais quanto para E. Coli . Os resultados encontrados mostraram-se satisfatorios na eliminacao dos coliformes termotolerantes, mas especificamente a bacteria Escherichia coli . Entretanto, na eliminacao de bacterias Coliformes presentes nas amostras apenas a radiacao solar demonstrou eficiencia.

Background: Increased frequency and intensity of droughts related to climate change are predicted to induce pressure on herbaceous communities. Considering that forbs contribute significantly to savanna ecosystem resilience, we investigated forb communities of a protected semi-arid savanna during an extensive drought.Objective: We identified drought-tolerant species with their related functional traits.Results: Drought-tolerant forb flora comprised of several plant families and species with overlapping traits, of which the ability to resprout was related to perennials, whereas succulence and prostrate growth form were typical annual forb dominance traits.Conclusion: Results highlight the functional importance of forbs and their resilience to drought events in protected areas.

Background: Low altitude Mopaneveld savanna in the northeastern parts of South Africa is generally well conserved. However, extensive copper mining, agricultural practices and urbanisation in the Phalaborwa region prompted research on the possible effects of land-use change on plant community diversity and function. Species diversity measures are usually considered adequate to assess disturbance effects to inform conservation efforts and management practices. However, diversity measures based on species level accounts often limit the outcomes of these studies as this approach fails to quantify how disturbances affect ecosystem functioning when community assembly, and not species diversity alone, is altered by land-use change.Objectives: The aim of this study was to apply both species and functional diversity measures to a data set derived from various land-use types (i.e. areas exposed to strip mining activities, communal farming practices and conservation) in the Phalaborwa region to examine the effects of land-use change on the community ecology of the herbaceous layer.Results: Land-use change, particularly severe top-soil disturbances through strip mining activities, had a significant filtering effect on all measures of species diversity, though functional evenness was maintained across land-use types.Conclusion: These results suggest that, despite initial species loss, this particular savanna ecosystem is buffered against anthropogenic disturbances through functional stability. Indicator species analyses, as well as relationships between plant functional types and land-use change, revealed that forb species are largely responsible for ecosystem stability in areas exposed to anthropogenic disturbances.

Review of: William Bond. 2019, Oxford University Press, Great Clarendon Street, Oxford, OX2 6DP, UK 192 pages, Hardcover, Paperback, Ebook ISBN-13: 978-0198812456DOI:10.1093/oso/9780198812456.001.0001$78 (~ R 1 135, Hardcover); $85 (~R 1 240, Ebook); $46 (~R 660, Paperback)

Attempts to obtain standardised decomposition data to determine potential drivers of carbon release have evolved from the use of cotton strips and standardised leaf litter mixtures to the most recent Tea Bag Index (TBI). The TBI is an internationally standardised method to collect comparable, globally distributed data on decomposition rate and litter stabilisation, using commercially available tea bags as standardised test kits. As this index was developed as a citizen science project in the northern hemisphere, we aimed to highlight the potential value – and pitfalls – of its application in a subtropical African savanna. We furthermore aimed to expand on existing protocol details and propose amendments to achieve an enhanced understanding of decomposition dynamics across temporal and spatial scales in African ecosystems. Proposed adaptations include extended incubation periods for long-term monitoring studies, the burial of more tea bags to account for potential losses, and the use of additional equipment to enhance effective sampling. These adaptations provide a system-specific protocol which can facilitate studies aimed to understand the interactions between top-down drivers (e.g. herbivory, fire, climate variability) and bottom-up controls (e.g. decomposition) in carbon flux dynamics of savanna ecosystems. Application of the proposed extended protocol in a semi-arid savanna provided results which reinforce the potential value of the TBI in an African context. Significance: The TBI is a relatively easy and cost-effective approach to gather globally distributed data on potential decomposition rate and inherent carbon flux, yet it was developed and primarily tested in boreal and temperate ecosystems. The use of more paired tea bag replicates and additional equipment is a viable means to mitigate tea bag losses to several savanna-based agents of disturbance, while enabling confident conclusions made from statistical results and improved estimates of the TBI. High recovery success across disturbance treatments and incubation periods suggest that the TBI can be applied successfully to spatial and temporal decomposition studies.

Fire and herbivory are important natural disturbances in grassy biomes. Both drivers are likely to influence be- lowground microbial communities but no studies have unravelled the long-term impact of both fire and herbiv- ory on bacterial and fungal communities. We hypothesized that soil bacterial communities change through disturbance-induced shifts in soil properties (e.g. pH, nutrients) while soil fungal communities change through vegetation modification (biomass and species composition). To test these ideas, we characterised soil physico- chemical properties (pH, acidity, C, N, P and exchangeable cations content, texture, bulk density, moisture), plant species richness and biomass, microbial biomass and bacterial and fungal community composition and di- versity (using 16S and ITS rRNA amplicon sequencing, respectively) in six long-term (18 to 70 years) ecological research sites in South African savanna and grassland ecosystems. We found that fire and herbivory regimes pro- foundly modified soil physico-chemical properties, plant species richness and standing biomass. In all sites, an increase in woody biomass (ranging from 12 to 50%) was observed when natural disturbances were excluded. The intensity and direction of changes in soil properties were highly dependent on the topo-pedo-climatic con- text. Overall, fire and herbivory shaped bacterial and fungal communities through distinct driving forces: edaphic properties (including Mg, pH, Ca) for bacteria, and vegetation (herbaceous biomass and woody cover) for fungi. Fire and herbivory explained on average 7.5 and 9.8% of the fungal community variability, respectively, compared to 6.0 and 5.6% for bacteria. The relatively small changes in microbial communities due to natural disturbance is in stark contrast to dramatic vegetation and edaphic changes and suggests that soil microbial communities, having evolved with disturbance, are resistant to change. This represents both a buffer to short-term anthropogenic- induced changes and a restoration challenge in the face of long-term changes. Ecological drivers Grassland Next generation sequencing Savanna Soil microbial diversity South Africa

Background: Land-use effects on grassland flora are difficult to predict due to poor understanding of species losses caused by transformation.Objectives: To determine changes in species diversity and composition by comparing transformed with untransformed grassland.Methods: Floristics of paired plots were sampled within 18 transformed sites (representing agricultural and urban land-uses) and neighbouring untransformed grassland.Results: Endemic and threatened species were negatively affected by transformation, particularly species with belowground bud-banks and storage organs. Species composition, with clear shifts in dominant families, was changed by over 90% on average by transformation.Conclusion: Land-use transformation leads to the loss of native species and increased alien invasive species.

International audience

Ethnopharmacological relevance Sceletium tortuosum (L.) N.E.Br., the most sought after and widely researched species in the genus Sceletium is a succulent forb endemic to South Africa. Traditionally, this medicinal plant is mainly masticated or smoked and used for the relief of toothache, abdominal pain, as a mood-elevator, analgesic, hypnotic, anxiolytic, thirst and hunger suppressant, and for its intoxicating/euphoric effects. Sceletium tortuosum is currently of widespread scientific interest due to its clinical potential in treating anxiety and depression, relieving stress in healthy individuals, and enhancing cognitive functions. These pharmacological actions are attributed to its phytochemical constituents referred to as mesembrine-type alkaloids. Aim of the review The aim of this review was to comprehensively summarize and critically evaluate recent research advances on the phytochemistry, pharmacokinetics, biological, pre-clinical and clinical activities of the medicinal plant S. tortuosum. Additionally, current ongoing research and future perspectives are also discussed. Methods All relevant scientific articles, books, MSc and Ph.D. dissertations on botany, behavioral pharmacology, traditional uses, and phytochemistry of S. tortuosum were retrieved from different databases (including Science Direct, PubMed, Google Scholar, Scopus and Web of Science). For pharmacokinetics and pharmacological effects of S. tortuosum, the focus fell on relevant publications published between 2009 and 2021. Results Twenty-five alkaloids belonging to four structural classes viz: mesembrine, Sceletium A4, joubertiamine, and tortuosamine, have been identified from S. tortuosum, of which the mesembrine class is predominant. The crude extracts and commercially available standardized extracts of S. tortuosum have displayed a wide spectrum of biological activities (e.g. antimalarial, anti-oxidant, neuromodulatory, immunomodulatory, anti-HIV, neuroprotection) in in vitro or in vivo studies. While the plant has been studied in clinical populations, this has only been in healthy subjects, so that further study in pathological states remains to be done. Nevertheless, the aforementioned studies have demonstrated that S. tortuosum has potential for enhancing cognitive function and managing anxiety and depression. Conclusion As an important South African medicinal plant, S. tortuosum has garnered many research advances on its phytochemistry and biological activities over the last decade. These scientific studies have shown that S. tortuosum has various bioactivities. The findings have further established the link between the phytochemistry and pharmacological application, and support the traditional use of S. tortuosum in the indigenous medicine of South Africa.

Herbivory and fire are known to shape plant community structure and function in savanna ecosystems worldwide, yet these drivers are increasingly being altered in their behaviour, or completely excluded. Furthermore, herbaceous responses to rainfall in semi-arid and arid savannas may outweigh the effects of herbivory and fire, especially in nutrient-rich ecosystems. Despite considerable recognition of herbaceous responses to drivers in savanna systems, few studies consider grasses and forbs as distinct herbaceous functional entities. To address this shortcoming, we used long-term herbaceous vegetation data collected from herbivore and fire exclusion treatments in the Kruger National Park (KNP) in South Africa. We investigated response patterns in herbaceous abundances per functional group for three sampling years, which represented different rainfall conditions (i.e., average for 2010, above average for 2001, and below average for 2015. Dynamic shifts in forb versus grass dominance were revealed across treatments. Surprisingly, palatable annual forb communities seemed more resilient to herbivores, or their removal, dominating over palatable annual grass communities. Furthermore, unpalatable perennial forbs were revealed to be more resilient to herbivore presence than their absence. Palatable perennial grass abundances were consistently enhanced by above-average rainfall conditions, whereas equal dominance of palatable grasses and forbs was evident during the drought year. This highlights that palatable perennial functional groups (not grasses alone) provide important ecosystem functions, such as forage stability, and hence functional redundancy to absorb disturbances such as droughts. Moreover, rainfall variability and herbivory are considered the main drivers of palatable perennial functional groups in this nutrient-rich ecosystem. Palatable perennial grass abundances differed significantly from other alleged unfavourable herbaceous functional groups (e.g., unpalatable perennial grasses, annual grasses, and annual and perennial forbs) and, although they presented contrasting patterns for each sampling year, fire and herbivory treatments, palatable perennial grasses remained the dominant functional group in this ecosystem type. Therefore, this study did not support previous findings that conditions such as drought, fire and herbivory favour unfavourable functional groups at the expense of palatable perennial grasses. Observed patterns provide evidence of a dynamic and less predictable coexistence between grasses and forbs.

Objectives We report on a large prospective, multicentre clinical investigation on inter- and intrapatient genetic variability for antimicrobial resistance of Helicobacter pylori . Methods Therapy-naive patients ( n = 2004) who had undergone routine diagnostic gastroscopy were prospectively included from all geographic regions of Austria. Gastric biopsy samples were collected separately from antrum and corpus. Samples were analysed by histopathology and real-time PCR for genotypic resistance to clarithromycin and quinolones. Clinical and demographic information was analysed in relation to resistance patterns. Results H. pylori infection was detected in 514 (26%) of 2004 patients by histopathology and confirmed in 465 (90%) of 514 patients by real-time PCR. PCR results were discordant for antrum and corpus in 27 (5%) of 514 patients, indicating inhomogeneous infections. Clarithromycin resistance rates were 17% (77/448) and 19% (84/455), and quinolone resistance rates were 12% (37/310) and 10% (32/334) in antrum and corpus samples, respectively. Combination of test results per patient yielded resistance rates of 21% (98/465) and 13% (50/383) for clarithromycin and quinolones, respectively. Overall, infection with both sensitive and resistant H. pylori was detected in 65 (14%) of 465 patients. Conclusions Anatomically inhomogeneous infection with different, multiple H. pylori strains is common. Prospective clinical study design, collection of samples from multiple sites and microbiologic methods that allow the detection of coinfections are mandatory for collection of reliable data on antimicrobial resistance patterns in representative patient populations. (ClinicalTrials.gov identifier: NCT02925091).

The genusMerremiaDennst. ex Endl. (Convolvulaceae) is a rich source of structurally diverse phytochemicals with therapeutic relevance. This review presents the first comprehensive, up-to-date information and research progression on the nutritional value, ethnomedicinal uses, phytochemistry, pharmacological activities, and toxicity of the genusMerremia. Using the key search term “Merremia”, relevant documents and information were retrieved from electronic databases. Relevant documents were uploaded in RStudio with installed bibliometric software packages and used for data retrieval, tabulation, and network visualization. Bibliometric analysis revealed that ca. 55% of the studies related toMerremiawere published in the last decade, which can be grouped into four thematic areas: (i) drug formulation, (ii) taxonomy, (iii) chemical analysis, and (iv) treatment of diseases. Ethnomedicinal uses, phytochemistry, and biological activities studies showed that species in the genus are promising medicinal plants with various pharmaceutical potentials. However, clinical studies to validate the efficacy of the reported bioactivities and the mechanisms underlying the various activities are lacking and should constitute a future research focus. Additionally, reports on the nutritional and antinutritional constituents ofMerremiaspecies revealed that the species meet high nutritional quality criteria for animals and are therefore suitable for inclusion in livestock diets. The few available investigations on toxicity indicated that mostMerremiaspecies are safe for human and animal use but not with prolonged chronic administration.

Photodynamic therapy (PDT) is a palliative treatment for malignant biliary obstruction.The objective of this article is to assess the feasibility and safety of this technique.In this nationwide, retrospective study of prospectively collected clinical data, all patients treated with PDT using polyhematoporphyrin in Austria from March 2004 to May 2013 were included. Feasibility, adverse events, stent patency and mortality rates were investigated.Eighty-eight patients (54 male, 34 female, median age 69 years) underwent 150 PDT procedures at seven Austrian referral centers for biliary endoscopy. The predominant underlying disease was Klatskin tumor (79/88). All PDT procedures were feasible without technical issues. Cholangitis was the most frequent adverse event (21/88). Stent patency was 246 days (95% CI 203-289) median and was significantly longer for metal than for plastic stents (269 vs. 62 days,PDT using polyhematoporphyrin was feasible and safe in this nationwide analysis. Survival data suggest a benefit of PDT in this unselected real-life patient population. Prospective trials comparing PDT to other palliative treatments will help to define its role in the management of malignant biliary obstruction. The study is registered at ClinicalTrials.gov number: NCT02504957.

Rainfall and herbivory shape savannah herbaceous communities, but these disturbances are being altered globally. To assess potential consequences of such alterations, we evaluated herbivore effects on species and functional diversity during an episodic drought in a sodic savannah using data collected from long‐term herbivore exclosures in the Kruger National Park, South Africa. Herbaceous life forms are rarely acknowledged as distinct functional entities. Moreover, the functional ecology of forbs remains elusive. Here, we present disturbances–responses by forbs separately from grasses. We hypothesised that combinations of intense utilisation and drought would be associated with low diversity and high dominance at species and functional levels for both life forms. Contrary to our hypothesis, low forb and grass diversity was associated with long‐term herbivore exclusion, which exceeded expected undesirable effects of intense utilisation and drought. Grasses responded less sensitively, suggesting that forbs respond dynamically to changes in herbivore assemblage when these alterations are combined with drought. Consistent with patterns in savannah systems, forbs contributed significantly to species and functional trait diversity. High forb diversity is suggested to enhance resilience of this nutrient‐rich ecosystem against declines in its functioning when subjected to drought and alterations in herbivory

Savannas are commonly described as a vegetation type with a grass layer interspersed with a discontinuous tree or shrub layer. On the contrary, forbs, a plant life form that can include any nongraminoid herbaceous vascular plant, are poorly represented in definitions of savannas worldwide. While forbs have been acknowledged as a diverse component of the herbaceous layer in savanna ecosystems and valued for the ecosystem services and functions they provide, they have not been the primary focus in most savanna vegetation studies. We performed a systematic review of scientific literature to establish the extent to which forbs are implicitly or explicitly considered as a discrete vegetation component in savanna research. The overall aims were to summarize knowledge on forb ecology, identify knowledge gaps, and derive new perspectives for savanna research and management with a special focus on arid and semiarid ecosystems in Africa. We synthesize and discuss our findings in the context of different overarching research themes: (a) functional organization and spatial patterning, (b) land degradation and range management, (c) conservation and reserve management, (d) resource use and forage patterning, and (e) germination and recruitment. Our results revealed biases in published research with respect to study origin (country coverage in Africa), climate (more semiarid than arid systems), spatial scale (more local than landscape scale), the level at which responses or resource potential was analyzed (primarily plant functional groups rather than species), and the focus on interactions between life forms (rather seldom between forbs and grasses and/or trees). We conclude that the understanding of African savanna community responses to drivers of global environmental change requires knowledge beyond interactions between trees and grasses only and beyond the plant functional group level. Despite multifaceted evidence of our current understanding of forbs in dry savannas, there appear to be knowledge gaps, specifically in linking drivers of environmental change to forb community responses. We therefore propose that more attention be given to forbs as an additional ecologically important plant life form in the conventional tree–grass paradigm of savannas.

Herbivores alter plant biodiversity (species richness) in many of the world’s ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory predicts that herbivores enhance plant biodiversity at high productivity but have the opposite effect at low productivity. Yet, empirical support for the importance of site productivity as a mediator of these herbivore impacts is equivocal. Here, we synthesize data from 252 large-herbivore exclusion studies, spanning a 20-fold range in site productivity, to test an alternative hypothesis—that herbivore-induced changes in the competitive environment determine the response of plant biodiversity to herbivory irrespective of productivity. Under this hypothesis, when herbivores reduce the abundance (biomass, cover) of dominant species (for example, because the dominant plant is palatable), additional resources become available to support new species, thereby increasing biodiversity. By contrast, if herbivores promote high dominance by increasing the abundance of herbivory-resistant, unpalatable species, then resource availability for other species decreases reducing biodiversity. We show that herbivore-induced change in dominance, independent of site productivity or precipitation (a proxy for productivity), is the best predictor of herbivore effects on biodiversity in grassland and savannah sites. Given that most herbaceous ecosystems are dominated by one or a few species, altering the competitive environment via herbivores or by other means may be an effective strategy for conserving biodiversity in grasslands and savannahs globally. Fil: Koerner, Sally E.. University of North Carolina at Greensboro. Department of Biology; Estados Unidos Fil: Smith, Melinda D.. State University of Colorado - Fort Collins; Estados Unidos Fil: Burkepile, Deron E.. University of California; Estados Unidos Fil: Hanan, Niall P.. New Mexico State University; Estados Unidos Fil: Avolio, Meghan L.. University Johns Hopkins; Estados Unidos Fil: Collins, Scott L.. University of New Mexico; Estados Unidos Fil: Knapp, Alan K.. State University of Colorado - Fort Collins; Estados Unidos Fil: Lemoine, Nathan P.. State University of Colorado - Fort Collins; Estados Unidos Fil: Forrestel, Elisabeth J.. University of California at Davis; Estados Unidos Fil: Eby, Stephanie. Northeastern University; Estados Unidos Fil: Thompson, Dave I.. University of the Witwatersrand; Sudáfrica. Kruger National Park. South African Environmental Observation Network. Ndlovu Node. Scientific Services; Sudáfrica Fil: Aguado-Santacruz, Gerardo A.. Tecnológico Nacional de México; México Fil: Anderson, John P.. New Mexico State University; Estados Unidos Fil: Anderson, T. Michael. University Wake Forest; Estados Unidos Fil: Angassa, Ayana. Botswana University of Agriculture and Natural Resources; Sudáfrica. Hawassa University; Etiopía Fil: Bagchi, Sumanta. Indian Institute of Science; India Fil: Bakker, Elisabeth S.. Netherlands Institute of Ecology; Países Bajos Fil: Bastin, Gary. Alice Springs; Australia Fil: Baur, Lauren E.. University of New Mexico; Estados Unidos Fil: Beard, Karen H.. State University of Utah; Estados Unidos Fil: Beever, Erik A.. United States Geological Survey; Estados Unidos. State University of Montana; Estados Unidos Fil: Bohlen, Patrick J.. University of Central Florida; Estados Unidos Fil: Boughton, Elizabeth H.. MacArthur Agroecology Research Center; Estados Unidos Fil: Canestro, Don. University of California; Estados Unidos Fil: Cesa, Ariela. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; Argentina Fil: Chaneton, Enrique Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina Fil: Cheng, Jimin. Northwest A&F University; China Fil: D?Antonio, Carla M.. University of California; Estados Unidos Fil: Deleglise, Claire. Université Grenoble Alpes; Francia Fil: Dembélé, Fadiala. Institut de Formation et de Recherche Appliquee; Sudáfrica Fil: Dorrough, Josh. Ecosystem Mangement Science; Austria Fil: Eldridge, David J.. University of New South Wales; Australia Fil: Fernandez Going, Barbara. University of Texas at Austin; Estados Unidos Fil: Fernández Lugo, Silvia. Universidad de La Laguna; España Fil: Fraser, Lauchlan H.. Thompson Rivers University; Canadá Fil: Freedman, Bill. Dalhousie University Halifax; Canadá Fil: García Salgado, Gonzalo. Dalhousie University Halifax; Canadá Fil: Goheen, Jacob R.. University of Wyoming; Estados Unidos Fil: Guo, Liang. Northwest A&F University; China Fil: Husheer, Sean. New Zealand Forest Surveys; Nueva Zelanda Fil: Karembé, Moussa. Université des Sciences; Malí Fil: Knops, Johannes M. H.. Universidad de Nebraska - Lincoln; Estados Unidos Fil: Kraaij, Tineke. Nelson Mandela University; Sudáfrica Fil: Kulmatiski, Andrew. State University of Utah; Estados Unidos Fil: Kytöviita, Minna Maarit. Universidad de Jyvaskyla; Finlandia Fil: Lezama, Felipe. Universidad de la República; Uruguay Fil: Loucougaray, Gregory. Université Grenoble Alpes; Francia Fil: Loydi, Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentina Fil: Milchunas, Dan G.. State University of Colorado - Fort Collins; Estados Unidos Fil: Milton, Suzanne J.. South African Environmental Observation Network; Sudáfrica Fil: Morgan, John W.. La Trobe University; Australia Fil: Moxham, Claire. Arthur Rylah Institute for Environmental Research; Australia Fil: Nehring, Kyle C.. State University of Utah; Estados Unidos Fil: Olff, Han. University of Groningen; Países Bajos Fil: Palmer, Todd M.. University of Florida; Estados Unidos Fil: Rebollo, Salvador. Universidad de Alcalá; España Fil: Riginos, Corinna. The Nature Conservancy; Estados Unidos Fil: Risch, Anita C.. Swiss Federal Institute for Forest, Snow and Landscape Research; Suiza Fil: Rueda, Marta. Consejo Superior de Investigaciones Científicas. Estación Biológica de Doñana; España Fil: Sankaran, Mahesh. National Centre For Biological Sciences; India. University of Leeds; Reino Unido Fil: Sasaki, Takehiro. Yokohama National University; Japón Fil: Schoenecker, Kathryn A.. Fort Collins Science Center and Colorado State University; Estados Unidos Fil: Schultz, Nick L.. Federation University; Australia Fil: Schütz, Martin. Swiss Federal Institute for Forest, Snow and Landscape Research; Suiza Fil: Schwabe, Angelika. Universitat Technische Darmstadt; Alemania Fil: Siebert, Frances. North West University; Sudáfrica Fil: Smit, Christian. University of Groningen; Países Bajos Fil: Stahlheber, Karen A.. University of Wisconsin Green Bay; Estados Unidos Fil: Storm, Christian. Universitat Technische Darmstadt; Alemania Fil: Strong, Dustin J.. United States Department of Agriculture. Agriculture Research Service; Estados Unidos Fil: Su, Jishuai. Northwest A&F University; China Fil: Tiruvaimozhi, Yadugiri V.. National Centre for Biological Sciences; India Fil: Tyler, Claudia. University of California; Estados Unidos Fil: Val, James. Office of Environment and Heritage; Australia Fil: Vandegehuchte, Martijn L.. University of Ghent; Bélgica. Swiss Federal Institute for Forest, Snow and Landscape Research; Suiza Fil: Veblen, Kari E.. State University of Utah; Estados Unidos Fil: Vermeire, Lance T.. United States Department of Agriculture. Agriculture Research Service; Estados Unidos Fil: Ward, David. Kent State University; Estados Unidos Fil: Wu, Jianshuang. Lhasa National Ecological Research Station; China Fil: Young, Truman P.. University of California at Davis; Estados Unidos. Mpala Research Centre; Kenia Fil: Yu, Qiang. Chinese Academy Of Agricultural Sciences; China. Institute of Agricultural Resources and Regional Planning; China Fil: Zelikova, Tamara Jane. University Of Wyoming; . University of Wyoming; Estados Unidos

Ecological models to explain savanna heterogeneity and functioning weakly represent herbaceous forbs, which inevitably created knowledge gaps regarding the diversity and ecology of forbs. Forbs constitute over 70% of semi-arid savanna species richness. The aim of this study was therefore to (i) identify forb species that potentially form part of herbivore diet, and (ii) determine forb browsing intensity across a granitic savanna catenal sequence. Localized contrasts between nutrient-poor dystrophic uplands and nutrient-rich eutrophic bottomlands led us to predict that bottomlands would host forb assemblages dominated by browsed species. Forbs contributed to 78% of the total herbaceous layer species richness, of which 43% were browsed at varying intensities along the catenal sequence. Each topographic zone hosted a unique assemblage of browsed forbs, although browsing intensity was highest in the sodic bottomlands. Some browsed forbs formed prostrate, stoloniferous covers on the bottomlands, creating a lawn type dominated by forbs. Results presented here are the first to identify browsed forb species and to illustrate the turnover in browsing intensity of forbs across a semi-arid savanna catenal sequence. Our results add weight to the need to include herbaceous forbs in savanna management models to better understand savanna resource ecology and heterogeneity.

Fuelwood is the primary energy source for most Bhutanese and comprises 70% of national energy consumption. Nevertheless, forest cover and fuelwood supplies have increased in recent decades. The Government of Bhutan is committed to renewable energy develop- ment, reduced fossil fuel use, and sustainable forest management, but has not developed its wood biomass potential. We suggest that promoting research and policies to increase managed fuelwood harvesting could help meet national energy independence, rural in- come and employment, forest management and biodiversity conservation objectives. Managed fuelwood harvesting will require site-specific assessments of resource avail- ability, local needs and market demands, and rigorous monitoring and enforcement.

Plant functional traits provide a valuable tool to improve our understanding of ecological processes at a range of scales. Previous handbooks on plant functional traits have highlighted the importance of standardising measurements of traits to improve our understanding of ecological and evolutionary processes. In open ecosystems (i.e. grasslands, savannas, open woodlands and shrublands), traits related to disturbance (e.g. herbivory, drought, and fire) play a central role in explaining species performance and distributions and are the focus of this handbook. We provide brief descriptions of 34 traits and list important environmental filters and their relevance, provide detailed sampling methodologies and outline potential pitfalls for each trait. We have grouped traits according to plant functional type (grasses, forbs and woody plants) and, because demographic stages may experience different selective pressures, we have separated traits according to the different plant life stages (seedlings saplings and adults). We have attempted to not include traits that have been covered in previous handbooks except for where updates or additional information was considered beneficial.

The distinctiveness of Maputaland Woody Grassland lies within its richness of geoxylic suffrutices and herbaceous flora. Since it is well documented in the literature and easy to distinguish from other grassland types, it was possible to confirm a locality of this unique vegetation unit west of Richards Bay, where it probably forms the southernmost outlier population of this vegetation unit in the Indian Ocean Coastal Belt Biome. Phytosociological data obtained from the study area were analysed to identify plant communities and subsequent mapping units. Floristic gradients obtained through ordination techniques revealed the relationship that exists between the Woody Grassland of the study area and the Maputaland Woody Grassland of Sileza Nature Reserve. This confirms the occurrence of Maputaland Woody Grassland at Richards Bay. Two of the plant communities identified from the Richards Bay site are distinctively different, despite previously being lumped together by different authorities as either Kwambonambi Grassland or Maputaland Woody Grassland.

Very little is known about the relations between aloes and soil metals, despite evidence that aloes often form dense populations on metalliferous soils. This study targeted eight rock outcrops where aloes dominated the vegetation to determine whether these succulents have a preference for soils rich in heavy metals and whether they accumulate any of these metals in their leaf tissue. Soil analyses suggested that densely populated rock outcrops are rarely characterised by high concentrations of heavy metals. Analyses of leaf material revealed no metal hyperaccumulators, with most species acting as excluders of most metals. The only metals to be reflected in leaf material to some degree across populations were copper (mean of 4 µg g-1), iron (mean of 208 µg g-1), manganese (mean of 342 µg g-1) and zinc (mean of 31 µg g-1)(all values are based on leaf dry weight). Aloe greatheadii plants from the ultramafic-peralkaline Koedoesfontein Complex in the Vredefort Dome contained the highest concentrations of Mn (558 µg g-1) and were subjected to further sampling across four geological substrates to determine the limits of its accumulation ability (mean of 855 µg g-1 on wehrlite). This aloe was found to be non-hyperaccumulating, but tolerant to elevated Mn concentrations in its tissue. The uptake of Mn from the soil was not so much influenced by soil available Mn, but rather by decreasing pH, and increasing electric conductivity and soil potassium.

The Primary Math Assessment (PMA) tool is increasingly being used in multiple districts in a northwestern state. The PMA provides both screening and diagnostic information in six domains to assess mathematical proficiency in young students in their early educational years. A previous study using multidimensional Rasch analyses found support for the PMA’s six-dimensional theoretical framework, and that the PMA is a reliable mathematics assessment for early grades. This study extended the examination of a Rasch model, implementing exploratory and confirmatory factor analysis, Item Response Theory, and Differential Item Functioning analyses. In doing so, this study found an IRT 2-PL model to fit best with these data and provided ways to improve the accuracy of measuring mathematical proficiency in early grades.

The need to conduct research on the impact of elephant on the environment prompted the construction of exclosures along two of the most important rivers in the Kruger National Park. Scientific research on these exclosures along the Sabie and Letaba rivers addresses how patterns of spatial and temporal heterogeneity of the riparian zone are affected by fire, flood and herbivory. To further assist this research programme, a vegetation survey was conducted at the Nkhuhlu exclosure site along the Sabie River to classify and map the vegetation of the area. This will provide baseline data to assess future changes in vegetation and floristic patterns due to small-scale environmental factors created by the presence/absence of herbivory and fire. Phytosociological data were analysed to identify plant communities and subsequent mapping units. Five plant communities, ten sub-communities and four variants were recognised and described in relation to prevailing soil forms. Differences in species richness, diversity and community structure of the plant communities are clearly articulated. http://www.scielo.org.za/scielo.php?pid=S0075-64582008000100015&script=sci_arttext http://www.koedoe.co.za/index.php/koedoe/article/download/138/738

Rattan, Old World climbing palm, is an extremely valuable nontimber forest product whose canes are gathered for both market and nonmarket uses. I evaluated the effects of harvesting commercial rattan, Calamus zollingeri Becc., on genet survival and ramet demography in two primary forest sites near Lore Lindu National Park in Sulawesi, Indonesia. I monitored 168 permanently marked C. zollingeri genets for 4 years and surveyed random transects for C. zollingeri genet and ramet populations and evidence of cane harvesting in 1996 and 2000. Cane harvesting had no significant effect on genet survival or mean ramet densities. However, current cane extraction rates significantly reduced mean cane lengths and total available cane throughout the area during the study period. Based on observed genet and ramet populations and average cane growth rates of 1.4 m/year, the sustained-yield harvesting potential of C. zollingeri is approximately 101 m and 56 m/ha/year in the two study sites. Although C. zollingeri exhibits life-history traits well suited to sustained-yield harvesting, including production of multiple canes, cane resprouting following harvest, rapid cane growth, and widespread abundance below 1100 m, current harvest rates exceed growth and yield, and supplies of cane are being depleted. Rattan harvesting is widespread in Lore Lindu National Park. Approximately 18% of the park (42,000 ha) is likely subject to intensive and unsustainable extraction of C. zollingeri. Resumen: El ratan, palma trepadora del Viejo Mundo, es un producto forestal no maderable extremadamente valioso cuyas canas son colectadas tanto para usos de mercado como no mercado. Evalue los efectos de la cosecha del ratan comercial, Calamus zollingeri Becc., sobre la supervivencia de genet y demografia de ramulas en dos sitios de bosque primario cerca del Parque Nacional Lore Lindu en Sulawesi, Indonesia. Durante 4 anos monitoree 168 genets de C. zollingeri marcados permanentemente y revise transectos aleatorios en busca de poblaciones de genet y ramulas de C. zollingeri, asi como evidencia de cosecha de canas en 1996 y 2000. La cosecha de canas no tuvo efecto significativo sobre la supervivencia de genets ni las densidades promedio de ramulas. Sin embargo, las tasas de extraccion de cana actuales redujeron significativamente la longitud promedio de las canas y la disponibilidad total de canas en toda el area durante el periodo de estudio. Con base en poblaciones observadas de genets y ramulas y las tasas promedio de crecimiento de canas de 1.4 m/ano, el potencial de cosecha de produccion sostenida de C. zollingeri es de aproximadamente 101m y 56m/ha/ano en los dos sitios estudiados. Aunque C. zollingeri exhibe caracteristicas adecuadas para cosechas de produccion sostenida, incluyendo la produccion de canas multiples, rebrote de canas despues de la cosecha, crecimiento rapido de canas y amplia abundancia debajo de los 1100 m, las tasas de cosecha actuales exceden el crecimiento y produccion, y las reservas de cana se estan agotando. La cosecha de ratan es extensiva en el Parque Nacional Lore Lindu. Es probable que aproximadamente el 18% del parque (42,000 ha) este sujeto a la extraccion intensiva y no sostenible de C. zollingeri.

A hierarchical classification, description, and ecological and floristic interpretations are presented on the vegetation types of the ultramafic rock habitats of the Sekhukhuneland Centre of Plant Endemism. Relevés were compiled in 100 stratified random plots. A TWINSPAN classification, refined by Braun-Blanquet procedures, revealed 17 plant communities, which are classified into 13 associations belonging to four proposed alliances. Many new syntaxa are ecologically interpreted and described. For each syntaxon, the species richness, endemism and conservation status was determined. Much of the plant community distribution can be ascribed to specific habitat preference. The floristic and habitat information, proposed classification, general description and vegetation key are provided to aid future identification of conservation areas, land use planning and research. An ordination (DECORANA) based on floristic data confirmed potential relationships that could exist between the plant communities and associated habitats and environmental gradients.

The D96N mutant of bacteriorhodopsin has often been taken as a model system to study the M intermediate of the wild type photocycle due to the long life time of the corresponding intermediate of the mutant. Using time-resolved step-scan FTIR spectroscopy in combination with a sample changing wheel we investigated the photocycle of the mutant with microsecond time resolution. Already after several microseconds an intermediate similar to the MN state is observed, which contrasts with the M state of the wild type protein. At reduced hydration M and N intermediates similar to those of wild type BR can be detected. These results have a bearing on the interpretation of the photocycle of this mutant. A mechanism is suggested for the fast rise of MN which provides some insight into the molecular events involved in triggering the opening of the cytosolic channel also of the wild type protein.

This study documents the abundance, distribution and knowledge of medicinal plant species in a Ransa Dayak village and adjoining forest in West Kalimantan, Indonesia. Over 250 medicinal plant species from 165 genera and 75 families are utilized by the local healer. Late successional, primary and river bench forests contained the highest diversity of locally-utilized medicinal species and the greatest number of species restricted to a single forest type for which alternative species or remedies were unavailable. Epiphytes and trees restricted to primary forests are particularly important sources for plants used to treat unusual ailments. A 100% survey of village residents 15 years of age and older (N = 32) revealed that people older than 25 years of age, and older females in particular, possessed greater knowledge of medicinal plants and their uses than younger people and males. All residents, except the male healer, were more knowledgeable about medicinal plants found in early successional forests than those of primary forests. Commercial logging and the loss of traditional knowledge through acculturation pose twin challenges to the persistence of traditional medicinal plant use in this Ransa village and throughout much of Kalimantan.

Purpose: To provide a method for calculating the transmission of any broad photon beam with a known energy spectrum in the range of 20-1090 keV, through concrete and lead, based on the superposition of corresponding monoenergetic data obtained from Monte Carlo simulation. Methods: MCNP5 was used to calculate broad photon beam transmission data through varying thickness of lead and concrete, for monoenergetic point sources of energy in the range pertinent to brachytherapy (20-1090 keV, in 10 keV intervals). The three parameter empirical model introduced byArcher et al. ["Diagnostic x-ray shielding design based on an empirical model of photon attenuation," Health Phys. 44, © 2014 American Association of Physicists in Medicine. © 2014 Am. Assoc. Phys. Med.

Understanding relationships between large herbivores and plant species diversity in dynamic riparian zones is critical to biodiversity conservation. The Nkuhlu exclosures in the Kruger National Park (KNP) provided opportunity to investigate spatial heterogeneity patterns within riparian zones, as well as how these patterns are affected by fire and herbivory. A monitoring project was initiated to answer questions about the dynamics of the herbaceous layer and was aimed at determining, (1) whether there exists meaningful variance in herbaceous plant species richness and diversity across different treatments in the ecologically sensitive sodic zone and (2) whether an increase in herbaceous biomass, an artefact of herbivory and fire exclusion, suppresses herbaceous plant species diversity and richness. Herbaceous vegetation was sampled in two 1 m2 circular sub-plots in the eastern and western corners of 81 fixed plots. The biomass of each plot was estimated with a disc pasture meter (DPM) diagonally with the plot. DPM-readings were converted to kg/ha, according to the latest conversions for the Lowveld Savanna. Species richness and biomass showed significant variance across treatments, whereas no significant variation in herbaceous species diversity was perceived. Combined treatment of fire absence and herbivore presence contributed to higher forb species richness in the sodic zone. Biomass is significantly higher in fully fenced areas where herbivores are excluded, as opposed to the open and partially fenced areas. Although no significant variation was recorded for diversity across treatments, lowest diversity was recorded in the absence of all herbivores, especially in combination with fire treatment. Therefore herbivores are essential in sustaining herbaceous plant species richness in the sodic zone, whilst no significant results were found with regard to their effect on species diversity. Although statistically non-significant, fire seems to suppress species richness.Conservation implications: This study could be used as framework to advance and develop science-based management strategies for, at least, the sodic zones of the KNP. Research in these exclosures will create better understanding of these landscapes, benefit ecosystem conservation planning of national parks and also provide valuable long-term information on key ecological processes.

Reseach was done on the Sodics of the Nkuhlu long-term monitoring exclosures.Variation in different plant characteristics were analised across different treatments over time. No significant variation in morphological types could be detected.

Die groot vloede wat in die jaar 2000 in die Kruger Nasionale Park plaasgevind het, het die rivieroewerplantegroei versteur. Dit het die geleentheid gebied om heinings op te rig langs die Sabierivier om herbivore uit sekere gebiede uit te sluit en sodoende die herstel van die rivieroewerekosisteme te monitor.

Die groot vloede wat in die jaar 2000 in die Kruger Nasionale Park plaasgevind het, het dierivieroewerplantegroei versteur. Dit het die geleentheid gebied om heinings op te rig langsdie Sabierivier om herbivore uit sekere gebiede uit te sluit en sodoende die herstel van die rivieroewerekosisteme te monitor.

Savanna ekosisteme in Suid-Afrika word gekenmerk deur heterogeniteit op verskeie skale

The construction of exclosures along two of the most important rivers in the Kruger National Park was done to investigate how patterns of spatial and temporal heterogeneity of the riparian zone is affected by fire, flood and herbivory. To assist this research programme, vegetation surveys were conducted within exclosures along the Letaba River to classify and map the vegetation of the area. The history and experimental design of the Letaba exclosures are similar to that of the Nkhuhlu exclosures along the Sabie River, which is directly related to questions surrounding elephant management. The main difference between the Nkhuhlu and Letaba exclosures is local heterogeneity, since the latter lies within the Mopaneveld, which is floristically and physiognomically much more homogenous than the vegetation of the southern Kruger National Park. Nevertheless, four plant communities, eight sub-communities and six variants were recognised and mapped for the Letaba exclosures. The vegetation description was done in relation to prevailing soil forms, differences in species richness, diversity and community structure, and therefore should serve as a basis for further detailed and broad-based botanical studies. Vegetation mapping was done to sub-community level and, where possible, to variant level. As expected in Mopaneveld vegetation, the plant communities could broadly be related to soil types, although smaller-scale variations correspond to soil moisture availability because the Mopaneveld is considered ‘event-driven’, especially in the herbaceous layer.Conservation implications: Floristic surveying and vegetation mapping of a long-term monitoring site, such as the Letaba exclosures, is seen as a baseline inventory to assist natural resource management. Linking mapping units to biodiversity strengthens the understanding needed to maintain biodiversity in all its natural facets and fluxes.