bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resource flows, crops and soil fertility management in smallholder farming systems in semi‐arid Zimbabwe
Authors: Ncube B. , Twomlow S. J. , Dimes J. P. , Van Wijk M. T. , Giller K. E. 
Published: February 2009

AbstractPoor soil fertility and erratic rains are major constraints to crop production in semi‐arid environments. In the smallholder farming systems of sub‐Saharan Africa, these constraints are manifested in frequent crop failures and endemic food insecurity. We characterized a semi‐arid smallholder farming system in south‐western Zimbabwe to assess crop production, nutrient use and factors that constrain productivity. The farming system was studied using resource flow mapping, farmer interviews and calculations of crop production over three cropping seasons (2002/2003, 2003/2004 and 2004/2005) to capture variability between years. Farmers were categorized into three groups: better resourced, medium resourced and poorly resourced. Better resourced farmers produced adequate grain for basic household consumption, except in the drought year (2002/2003). Poorly resourced farmers had large grain deficits, whereas the medium resourced class had smaller deficits. Better resourced and medium resourced farmers produced adequate amounts of staple cereal in two of the seasons, while poorly resourced farmers produced inadequate amounts of food in all three seasons. All farmers produced less than 300 kg/ha of legumes per season. Lack of seed was cited as the main reason for poor legume production. Better resourced farmers used animal manure (2000–5000 kg per season) and some fertilizer on their cereal crops, while the medium resourced group used less manure (1000 kg or less) and no fertilizer. The use of manure varied strongly across the years. Poorly resourced farmers used no nutrient inputs on any of their crops. All groups had negative nitrogen balances during the three cropping seasons, although the values varied strongly between seasons. Investigation of the potential strategies for developing sustainable production systems are required to address the problems of food security in the semi‐arid parts of the country and the region.
Relationship Between Basilar‐Type Migraine and Migrainous Vertigo
Authors: Wang Chi‐Te , Lai Mei‐Su , Young Yi‐Ho 
Published: February 2009

Objective.— This study compared clinical manifestations and audiovestibular function tests among subjects of basilar‐type migraine (BtM), definite and probable migrainous vertigo (dMV and pMV), in order to investigate the relationship between them.Background.— Various diagnostic criteria such as BtM, dMV, and pMV have been proposed. However, a comparison between these diagnostic groups has not been conducted before.Methods.— This study enrolled 77 subjects, including BtM in 15, dMV in 30, and pMV in 32 patients. All patients received structured interview of clinical presentations and underwent a battery of audiovestibular function tests.Results.— Demographic features were similar between 3 groups, including age, gender, precipitating factors, and family preponderance. When considering the clinical manifestations, for example motion sickness, migrainous symptoms, and sequential relationship between headache and vertigo, BtM and dMV groups shared similar features, but differed from pMV group. As regards to differentiate between BtM and dMV patients, the former revealed higher occurrence rates than the latter in relation to the frequency of vertigo attacks, neurological symptoms, and saccadic dysmetria.Conclusion.— The relationship between BtM, dMV, and pMV refers to a distribution of severity across the disease spectrum of migraine‐related vertigo. Of them, BtM group presents the most severe form in clinical manifestation and brainstem involvement, followed by dMV, and pMV is the mildest form.
Use of checkerboard DNA–DNA hybridization to evaluate the internal contamination of dental implants and comparison of bacterial leakage with cast or pre‐machined abutments
Authors: Do Nascimento Cássio , Barbosa Rodrigo Edson Santos , Issa João Paulo Mardegan , Watanabe Evandro , Ito Izabel Yoko , De Albuquerque Junior Rubens Ferreira 
Published: February 2009

AbstractAims: To evaluate the checkerboard DNA–DNA hybridization method for detection and quantitation of bacteria from the internal parts of dental implants and to compare bacterial leakage from implants connected either to cast or to pre‐machined abutments.Materials and methods: Nine plastic abutments cast in a Ni–Cr alloy and nine pre‐machined Co–Cr alloy abutments with plastic sleeves cast in Ni–Cr were connected to Branemark‐compatible implants. A group of nine implants was used as control. The implants were inoculated with 3 μl of a solution containing 108 cells/ml of Streptococcus sobrinus. Bacterial samples were immediately collected from the control implants while assemblies were completely immersed in 5 ml of sterile Tripty Soy Broth (TSB) medium. After 14 days of anaerobic incubation, occurrence of leakage at the implant–abutment interface was evaluated by assessing contamination of the TSB medium. Internal contamination of the implants was evaluated with the checkerboard DNA–DNA hybridization method.Results: DNA–DNA hybridization was sensitive enough to detect and quantify the microorganism from the internal parts of the implants. No differences in leakage and in internal contamination were found between cast and pre‐machined abutments. Bacterial scores in the control group were significantly higher than in the other groups (P<0.05).Conclusion: Bacterial leakage through the implant–abutment interface does not significantly differ when cast or pre‐machined abutments are used. The checkerboard DNA–DNA hybridization technique is suitable for the evaluation of the internal contamination of dental implants although further studies are necessary to validate the use of computational methods for the improvement of the test accuracy.
Evaluation of voxel values in mandibular cancellous bone: relationship between cone‐beam computed tomography and multislice helical computed tomography
Authors: Naitoh Munetaka , Hirukawa Akiko , Katsumata Akitoshi , Ariji Eiichiro 
Published: February 2009

AbstractObjective: Measurements of bone density in designed sites are important in presurgical imaging for dental implant treatment. However, the pixel or voxel values obtained from cone‐beam computed tomography (CT) images are not absolute values. Hence, the relationship between voxel values obtained from cone‐beam CT with a limited‐volume exposure field and a flat panel detector and bone mineral densities (BMDs) obtained from multislice CT was evaluated in the mandible.Material and methods: A total of 16 (four males and 12 females) patients who had undergone imaging for mandibular dental implant treatment using cone‐beam CT with Alphard VEGA and multislice CT were enrolled in this investigation.Cross‐sectional images of cone‐beam and multislice CT were reconstructed, and values of regions of interest (ROIs) in images were calculated.Results: A high‐level correlation between voxel values of cone‐beam CT and BMDs of multislice CT was observed (r=0.965).Conclusion: It was suggested that voxel values of mandibular cancellous bone in cone‐beam CT could be used to estimate bone density.
Computer‐Aided Detection in Breast Magnetic Resonance Imaging: a Review
Authors: Dorrius M. D. , Van Ooijen P. M. A. 
Published: February 2009

SummaryThe aim of this study is to give an overview on the accuracy of the discrimination between benign and malignant breast lesions on MRI with and without the use of a computer‐aided detection (CAD) system. One investigator selected relevant articles based on title and abstract. Ten articles were selected for this review. The CAD systems used in these articles were commercially available (CAD stream and 3T) or institution‐specific computer analysis system. The articles showed that CAD has the potential to improve the discrimination of benign from malignant breast lesions at MRI imaging, but there is insufficient evidence to assess whether the use of CAD systems would maintain or increase the sensitivity and specificity.
Controlling invasive Arrhenatherum elatius and promoting native prairie grasses through mowing
Authors: Wilson Mark V. , Clark Deborah L. 
Published: February 2009

Abstract. Control of invasive plants is a key element of conservation and restoration efforts. We report results from a five‐year field experiment in western Oregon, USA that evaluates the effects of different mowing regimes on the non‐native and invasive perennial grass Arrhenatherum elatius, the native perennial prairie grasses Danthonia californica and Festuca roemeri, and groups of other native and non‐native grasses and forbs. Eight treatments were designed to test hypotheses about the role of mowing height and time of application on the plant community.Differences among treatments emerged only after two or three years of treatment. This delay in response reinforces the need for long‐term studies. Annual mowing was most effective at reducing Arrhenatherum cover and flowering when applied in late spring or early summer, the time of Arrhenatherum flowering and expected maximum above‐ground allocation. Double mowing and mowing at 15 cm were more effective in reducing Arrhenatherum cover than were single mowing and mowing at 50 cm. All treatments increased the cover and flowering of Danthonia. Statistical model analysis showed that increases in cover and flowering of the native grass Danthonia were caused by its release from suppression by Arrhenatherum. Fouryears of the most effective treatment, mowing at 15 cm in late spring, converted an Arrhenatherum‐dominated site to a prairie dominated by native grasses. This is one of the few documented cases of pest plant control causing an increase in native plant abundance. These results show that mowing, properly applied, can be an effective tool for restoring degraded, Arrhenatherum‐dormnated prairies.
Classification, composition, richness and diversity of British hedgerows
Authors: French D.D. , Cummins R.P. 
Published: February 2009

Abstract. A floristic classification of British hedgerows is constructed. Hedges (the woody, structural element) and hedge‐bottoms (the mainly herbaceous ground flora) were analysed separately because different natural and management processes were expected to affect them.The 11 hedge classes varied in size from five to over 500 plots. Over two‐thirds of all hedges were dominated by Crataegus spp. or Primus spinosa. Hedge‐bottoms were more evenly grouped into four classes whose species composition could be related to broad land use/habitat types: intensive arable, rotational/mixed farming, managed grasslands, and woodland. The woodland class was only 12% of the total, and species characteristic of true woodland habitats were uncommon even within that class, so our data do not support the hypothesis of hedgerows acting as‘woodland corridors’for plants.Richness/diversity scores differed markedly between different hedge and hedge‐bottom classes. The richest hedgerows, both in species and inferred habitats, were among the rarer types, while the most common classes (both hedge and hedge‐bottom) were consistently the poorest.Comparison of species composition and diversity in hedges and hedge‐bottoms, and associations between them, all supported the hypothesis that the relative importance of historical, management and ecological effects differed between the two parts of the hedgerow; hedges and hedge‐bottoms should be treated ecologically as largely independent units.The classifications and richness/diversity scores enable easy preliminary assessment of the conservation value of a hedgerow. They also enable individual hedgerows to be placed in a wider (national) context.
Impact of land use changes on mountain vegetation
Authors: Tasser Erich , Tappeiner Ulrike 
Published: February 2009

Abstract. In this study the impact of land use changes on vegetation in the sub‐alpine‐alpine belt is analysed. The study sites (4.7 km2) are located in the Passeier Valley (South Tyrol, Italy), at an elevation of 1500–2300 m a.s.l. The whole study area was used for hay‐making ca. 60 yr ago. Today, part of the meadows are more intensively used, while other parts have been converted to pasture or have been abandoned.We analysed the reasons for these land use changes and the effects on vegetation with a Geographical Information System and geostatistical analysis. The result of these analyses are:(1) Current land use is mainly controlled by the degree of accessibility for vehicles. Accessible areas are being used more and more intensively, while poorly accessible areas are being abandoned or used as pasture.(2) Current vegetation is highly determined by current land use. Particular vegetation units can be assigned to each form of land use.(3) Succession starts immediately after abandonment. Depending on altitude, succession proceeds at different speeds and with different numbers of stages. Hence the type of vegetation indicates the time passed since abandonment.(4) Land use changes lead to characteristic changes in vegetation; they are considered to be the most important driving force for vegetation change.(5) Measures of intensification and abandonment of extensively used areas both lead to a decrease in the number of species.
Plant functional types: a promising tool for management and restoration of degraded lands
Authors: Gondard Hélène , Jauffret Sandrine , Aronson James , Lavorel Sandra 
Published: February 2009

Abstract. Throughout the Mediterranean region, vegetation dynamics are affected by human activities which are either ‘stresses’ or ‘disturbances’, depending on their frequency, intensity and spatial distribution. To minimize or reduce anthropogenic degradation caused by land use and other disturbances, it is necessary to understand and predict the various responses of plant communities to disturbances. In particular, detailed but integrative approaches are required to assimilate large databases on vegetation and to make them directly useful for managers and restorers.We describe two case studies undertaken to evaluate the effects of logging or overgrazing on plant species diversity in pine forests of southern France and steppe ecosystems of southern Tunisia. Both studies employed the same methodology to identify plant functional traits (morphological, life history and regeneration traits) associated with community response to disturbance. The results of these analyses allowed us to develop state and transition models that could be used to plan and predict ecosystem trajectories, assess ongoing degradation processes and monitor community and ecosystem responses to management and restoration practices. We discuss the relevance and the use of plant functional types (PFTs) as tools for ecosystem management and planning and for monitoring restoration in southern Europe, northern Africa and elsewhere. Using this approach it is possible to improve management strategies for the conservation, restoration and sustainable exploitation of biodiversity and of ecosystems.
Restoration, succession and climatic change
Authors: Wilson J. Bastow , White Peter S. , Bakker Jan P. , Díaz Sandra 
Published: February 2009

AbstractTwo outstanding papers on restoration and succession are briefly discussed as model papers for the type of research papers Appl. Veg.Sci. should publish. The paper on restoration concentrates on the introduction of hay to a site in order to speed up the introduction of target species. The paper on succession discusses the importance of plant colonization ‘windows’ opened by extreme weather events for succession and for offering optimum periods for intervention in restoration practice.Some remarks are also made on the electronic availability of ecology papers.
Population structure of the threatened perennial Serratula tinctoria in relation to vegetation and management
Authors: Bissels Stephanie , Hölzel Norbert , Otte Annette 
Published: February 2009

AbstractQuestion: How does vegetation and management affect the population stage structure of Serratula tinctoria, a species indicative of highly endangered and species‐rich flood‐plain meadows? Are different management regimes suitable to support viable populations of S. tinctoria?Location: Flood‐plain of the northern Upper Rhine, Germany.Methods: We analysed the population structure of S. tinctoria at 24 meadow sites which differed in vegetation and management. In this comparative study the investigated meadows were either (1) late mown in September; (2) early mown in June or (3) mown in June and then grazed by sheep.Results: The structure of the surrounding vegetation had a clear effect on the population structure of S. tinctoria. The percentage of bare soil, as well as the cover of bryophytes, were positively related, whereas the Ellenberg N‐value of the established vegetation was negatively related to the density and proportion of seedlings. Generally, we found only slight differences between the population structure of S. tinctoria in early and late mown meadows. Both management regimes had high densities of seedlings. In contrast, the meadow pastures supported significantly lower densities of seedlings and generative adults but relatively high densities of juveniles and vegetative adults, indicating a greater importance of clonal propagation under grazing pressure.Conclusions: Our results clearly showed that viable populations of S. tinctoria may occur in all of the studied management regimes. Although S. tinctoria was considered to be highly sensitive to early mowing, our findings suggest a facilitation of the species at more nutrient‐rich sites by mowing in June, which is also a benefit for the integration of management in farming systems.
Effects of fire on soil respiration, ATP content and enzyme activities in Mediterranean maquis
Authors: Fioretto A. , Papa S. , Pellegrino A. 
Published: February 2009

AbstractQuestion: Do low or high intensity fires affect micro‐organism activity in the upper soil layer of Mediterranean maquis?Location: 600 m from the sea in the Nature Reserve of Castel Volturno (Campania, southern Italy, 40°57’N; 13°55’E).Methods: Soil respiration was measured in situ on intact soil; enzyme activity (cellulase, xylanase, invertase, trehalase and protease) and ATP content were measured on soil samples collected under three species of maquis vegetation: Phillyrea angustifolia L., Myrtus communis L. and Cistus incanus L.Results: Soil microbial respiration showed no significant differences in CO2 flux in treated and untreated plots, but the ATP content in the soil under C. incanus and M. communis was lower in the treated plots for most of the study period. In the soil under Ph. angustifolia, ATP content was low only for one week after fire. The reduction was more marked in the samples from ‘high fire intensity’ than from ‘low fire intensity’ plots. Soil respiration and ATP content exhibited seasonal variations linked to soil water content. Among the enzyme activity measured in the soil under the three plant covers, only invertase declined in burned plots throughout the study period, particularly in the ‘high fire intensity’ plots. Activity of the enzymes cellulase, xylanase, trehalase and protease had a different sensitivity depending on the respective shrub cover.Conclusions: Impact of fire on soil microbial activity is largely dependent on vegetation mosaic and species identity.
Recording relative water table depth using PVC tape discolouration: Advantages and constraints in fens
Authors: Navrátilová Jana , Hájek Michal 
Published: February 2009

AbstractQuestion: Recognizing water table dynamics in wetlands is crucial for understanding species‐environment relationships, ecosystem function and changes during restoration. The PVC tape discolouration method enables spatially and temporally extensive studies of reductive conditions associated with long‐term water table dynamics in peat soils. The reliability of the method has been verified only for ombrotrophic bogs, even though wide usage can be expected in minerotrophic fens.Location: Třreboň basin, Czech Republic.Methods: Using data from 49 plots in six poor and moderately rich fens, we correlated the directly measured lowest, highest and mean water table depths and the same variables indicated by discolouration of PVC tape attached to green bamboo stakes installed vertically in the soil profile.Results: The depth to the first sign of PVC discolouration was highly correlated with the directly measured position of the highest water table, the correlation between the depth of complete discolouration and the directly measured position of the lowest water table was poorer. The accuracy of the minimum water table measurement depended on the depth of the peat layer. Surprisingly, the depth at which the green bamboo stakes turned brown correlated highly with the minimum water table.Conclusions: The PVC tape discolouration method reliably indicates water table maxima in fens, but minima are not accurately indicated. The depth of the green bamboo discolouration is suggested as a new alternative indicator of the minimum water table, even in fens and mineral soils. Combining both methods enables efficient monitoring of water table dynamics at a large number of mire sites.
Early stages of Calluna vulgaris regeneration after burning of coastal heath in central Norway
Authors: Nilsen Liv S. , Johansen Line , Velle Liv G. 
Published: February 2009

AbstractQuestions: How does Calluna vulgaris regenerate after burning wet and dry heaths of different age?Location: Central Norway.Methods: Patches of Calluna dominated old and young wet heath and old dry heath were burned. The mean temperatures reached in the categories of heath were measured. Cover, frequency, height and number of seedlings of Calluna were studied in plots.Results: The mean burning temperatures varied from 680 to 740°C, and were highest in wet heath that had not been burned for at least 50 years. Regeneration of Calluna was evident in the year of burning, but only from seeds. Even heath with a short burning interval lacked vegetative regeneration. Calluna cover increased yearly and exceeded 50 % three years after burning. Regeneration was evident in the year of burning, and was highest in heath with a short burning interval. The height increased regularly at all sites, but was most rapid in dry heath, probably because of better microclimatic conditions. There were more seedlings in the heath with a short burning interval.Conclusions: Calluna only regenerates from seeds afterburning in central Norway. The density of Calluna increased rapidly, which is positive for the conservation and management of coastal heaths in central Norway.