bluuebunny/crossref_metadata_2025_split huggingface dataset:
STUDIES UPON THE COPPER FUNGICIDES: THE DISTRIBUTION OF FUNGICIDAL PROPERTIES AMONG CERTAIN COPPER COMPOUNDS
Authors: MARSH R. W. , MARTIN H. , MUNSON R. G. 
Published: September 2010

SUMMARY

Field tests made in 1934, 1935 and 1936, using the control of potato blight as a criterion, showed that fungicidal powers were common to a wide range of copper compounds, namely, cuprous oxide, cupric oxide, cuprous cyanide, cuprous sulphite, cupric phosphate, cupric ammonium silicate and cupric oxychloride.
Both cuprous and cupric oxides were inferior in tenacity on potato foliage to Bordeaux mixture but the residues left on the leaves were superior in fungicidal power to Bordeaux residues of the same copper content.
In a field trial on pears, cuprous cyanide proved slightly inferior to an oil‐Bordeaux‐arsenate spray of similar copper content, when tested for the control of pear scab.
On apples, cuprous cyanide showed pronounced phytocidal properties.
STUDIES IN SOIL FUMIGATION: PRELIMINARY OBSERVATIONS
Authors: BYWATERS M. F. , POLLARD A. G. 
Published: September 2010

SUMMARY

Results of preliminary tests of possible methods of investigating the factors controlling the distribution of fumigant vapour in soil are described.
Sufficiently uniform and reproducible conditions of pore space in soil may be secured by packing at definite pressures and with a controlled moisture content.
A rapid approximate method for determining pore space is described.
Carbon disulphide may be satisfactorily removed from soil by aeration methods, and determined, after absorption in alcoholic potash, by the iodometric method.
Under the conditions of the experiment (injection of 2 oz. of carbon disulphide at 5 in. depth) the zone of high concentration of the vapour occurs at the level of injection and some 6–7 in. below it. Above the injection concentrations are definitely low.
Although movements of carbon disulphide by diffusion are probably dominant factors controlling its distribution in soil, the operation of a more slowly acting factor (possibly biological) effecting destruction of the vapour is indicated.
APPARATUS FOR GROWING PLANTS UNDER CONTROLLED ENVIRONMENTAL CONDITIONS
Authors: WILSON A. E. 
Published: September 2010

SUMMARYDetails are given of modifications of a Eothamsted Controlled Environment Chamber. These include an inexpensive cooling apparatus depending on the circulation of air through a car radiator through which cold or iced water is circulated by an electrically operated centrifugal pump. This apparatus enables temperatures down to 5° C. to be maintained at a room temperature of 16–18° C.Two types of humidifier are described. That finally adopted depends upon the passage of air through a fine water mist created by an atomizing device, the temperature of the water being maintained a few degrees above that of the air in the chamber.A method of drying air by passage over calcium chloride is described.Details of an inexpensive, simple and accurate, lineametric hair‐operated hygrostat are given. This instrument controls humidity within 2%Various minor modifications such as rough control of wind velocity within the chamber and a semi‐automatic watering device are described.
Pasture Improvement and the Control of Sheep Tick (Ixodes Ricinus L.)
Authors: Milne1 A. 
Published: September 2010

The sheep tick is confined almost entirely to rough, poor hill and moorland pastures. Agricultural improvement of these pastures involves (among other things) reduction in the depth of the vegetation layer and partial or complete destruction of the moisture‐holding underlying ‘mat’ of decaying vegetable matter. Assessment of the tick populations on improved and on comparable control areas showed a reduction in tick population following upon pasture improvement. But a fairly considerable degree of improvement is required to bring about a satisfactory reduction. Ticks were not completely extirpated even by ploughing. It is probable that pasture improvement affects tick population mainly by reducing cover and thus the humidity.Unfortunately, effective pasture improvement is not economic on hill and moorland grazings in general. Such improvement as is practicable could only be a supplement to other control measures.Since the sheep flock supports almost all the female ticks on a pasture, control is most likely to follow from the development of an efficient acaricidal sheep dip.
Aphis Migration and the Efficiency of the Trapping Method
Authors: Broadbent L. 
Published: September 2010

Reproducible results were obtained when adhesive traps for aphides were placed at the same height in different parts of a potato field. The total catches in different localities in different seasons can therefore justifiably be compared. During the summer dispersal flights, different species flew at different heights, so traps at one height only are not suitable for comparing the relative abundance of different species. There was less variation in numbers caught on traps at 3–4 ft. above the ground than on traps at 5–6 ft. or at ground‐level.During the first fortnight of July an average of 200 aphides, 1.6% of which were Myzus persicae, was caught on traps in the position of potato plants. Most of these were not potato aphides, but it is suggested that some of them might act as vectors of potato viruses. The number of aphides caught was roughly proportional to the volume of free air space around the traps, and as the foliage increased in density the numbers caught on lower traps decreased in proportion.Wind‐speed records within and above the crop are discussed and it is shown that conditions are often suitable for voluntary aphis flight in and near the crop on relatively windy days. Records of catches on the half‐traps facing the wind and on the other halves showed that voluntary flight decreased with increasing height.Brilliant yellow traps, coated with adhesive grease, caught more aphides than white traps, which in turn caught more than black.
Photosynthesis and Predisposition of Plants to Infection with Certain Viruses
Authors: Bawden F. C. , Roberts F. M. 
Published: September 2010

The effects on susceptibility to infection with certain viruses of subjecting plants to various periods of darkness or reduced illumination before and after inoculation were tested. The viruses and hosts used were a tobacco necrosis virus in French bean and tobacco; tomato aucuba mosaic virus in tobacco; and tobacco mosaic and tomato bushy stunt viruses in Nicotiana glutinosa. All the virus‐host combinations give necrotic local lesions, and susceptibility was measured by local lesion counts. Susceptibility was consistently increased by pre‐inoculation treatments of host plants, whereas post‐inoculation treatments had relatively little effect, but most often decreased susceptibility.Short periods in the dark produced similar responses to longer periods in shade, but the different plants varied in their response to, and tolerance of, darkness. The maximum number of lesions was usually obtained with bean plants kept for only 24 hr. in the dark before inoculation, but with tobacco plants susceptibility increased with increasing time in the dark up to 5 days.It is suggested that the successful establishment of infection occurs in two stages, the first of which is affected by. the accumulation of photosynthetic products. Whether these products confer resistance by increasing cell turgor or by reacting specifically with virus particles is unknown, but sap from plants in the light possesses no greater virus‐inhibiting power than sap from plants kept in the dark.
Variations in Belowground Carbon Storage and Soil CO2 Flux Rates along a Wet Tropical Climate Gradient1
Authors: McGroddy Megan , Silver Whendee L. 
Published: September 2010

ABSTRACTWe used a humid tropical elevation gradient to examine the relationships among climate, edaphic conditions, below‐ground carbon storage, and soil respiration rates. We also compared open and closed canopy sites to increase the range of microclimate conditions sampled along the gradient, and determine the effects of canopy openings on C and P storage, and C dynamics. Total soil C, the light C fraction, and all of the component fractions of the P pool were significantly related to soil moisture, and all but total soil C were also significantly related to temperature. Both labile and recalcitrant soil P fractions were negatively correlated with the light C fraction, while the dilute HCl‐extractable P pool, generally thought of as intermediate in availability, was positively correlated with light C, suggesting that P may play an important role in C cycling within these systems. Total fine root biomass was greatest at 1000 m elevation and lowest at 150 m, and was strongly and positively correlated with soil moisture content. Soil respiration rates were significantly and negatively correlated with fine root biomass and the light C fraction. In forested sites, soil respiration rates were strongly and negatively correlated with total belowground C pools (soils + roots + forest floor). Below‐ground C pools did not follow the expected increasing trend with decreases in temperature along the gradient. Our results indicated that in humid tropical forests, the relationships among soil C and nutrient pools, soil respiration rates, and climate are complex. We suggest that frequent and prolonged anaerobic events could be important features of these environments that may explain the observed trends.
Use of Coarse Woody Debris by the Plant Community of a Hawaiian Montane Cloud Forest1
Authors: Santiago Louis S. 
Published: September 2010

ABSTRACTMany species of woody plants in Hawaiian montane forests germinate on nurse logs or epiphytically, often developing aerial roots. This study investigated the role of fallen logs, wood fragments, and other forms of coarse woody debris (CWD; 35 cm diam.) in providing habitat for woody species in a forest with waterlogged soils. Oxidation‐reduction potentials (Eh) of root mats and nurse logs (−70.1 to 278.6 mV) were higher than the underlying soil horizons (−203.6 to −128.1 mV). CWD volume varied between 135.9 and 427.9 m3/ha. Live basal area varied between 18.4 and 29.7 m2/ha and increased with total CWD volume. Seedling and sapling abundances on nurse logs were correlated with moss coverage and decomposition class. Moss coverage was the only significant predictor of seedling density on nurse logs, whereas moss coverage and log volume were important for predicting sapling density. The proportion of woody plants established on logs was higher than in a younger Hawaiian montane forest site with well‐drained soils.
Seedling Mortality by Litterfall in Amazonian Forest Fragments1
Authors: Scariot Aldicìr 
Published: September 2010

ABSTRACTPhysical damage caused by litterfall is a source of seedling mortality that can be influenced by environmental disturbances, such as the isolation of forest fragments due to habitat destruction. The impact of physical damage in seedling mortality was evaluated in forest fragments and continuous forests in central Amazonia using artificial seedlings. A total of 11 reserves distributed among three sites were studied: three 1–ha, three 10–ha, two 100–ha, and three continuous forest reserves. In each reserve, ten transects each comprised of ten artificial seedlings were monitored for one year at four–week intervals. Survival curves were compared using failure time analysis, and the effect of reserve size on artificial seedling mortality after one year was analyzed with a categorical model. In the analysis of survival curves, artificial seedling survival was significantly greater in the continuous forest than in the 10–ha reserve at one site only, a result that may have occurred by chance. After one year, artificial seedlings suffered similar mortality due to litterfall among the reserves sampled. Physical damage by litterfall varied from 28 to 35 percent annually in the 1–and 10–ha forest fragments compared to 20 to 24 percent in the continuous forest. Mortality of artificial seedlings in the continuous forest was similar to other tropical sites in which the same method has been used, and may indicate that litterfall plays an important role in seedling mortality in the terra firme tropical forests of central Amazonia.
Reproductive Phenology of a Tropical Canopy Tree, Spondias mombin1
Authors: Adler Gregory H. , Kielpinski Kathleen A. 
Published: September 2010

ABSTRACTWe studied the reproductive phenology of isolated populations ofSpondias mombinto determine the degree of flowering and fruiting synchrony among populations and to examine spatial and temporal variability in fruit production. The study was conducted on six small islands (1.8–3.5 ha) in the Panama Canal. All individuals (10 cm in diameter at breast height (DBH) were marked in 1991 and censused each year through 1994 to record recruits and deaths. All marked trees were censused monthly for flowering and fruiting activity from April 1992 through December 1995.Spondias mombinwas seasonal and highly synchronous in flower and fruit production among islands and across years. Proportions of individuals fruiting varied among islands, years, and tree size classes. There was a positive relationship between probability of fruit production and tree size. Synchronous reproductive activity inS. mombinprobably was due to responses to proximate environmental cues such as fluctuations in irradiance, but other factors must have been responsible for temporal and spatial variation in reproductive performance. We suggest that this variation may have been due partly to temporal and spatial differences in pollinator abundance.
Entomophagy, Behavior, and Elongated Thoracic Legs in the Myrmecophilous Neotropical Butterfly Alesa amesis (Riodinidae)1
Authors: DeVries P. J. , Penz C. M. 
Published: September 2010

ABSTRACTEntomophagy in the riodinid butterfly tribe Eurybiini is demonstrated for the first time. Alesa amesis caterpillars and adults possess behavioral and morphological traits for feeding on Homoptera nymphs, and oviposition by A. amesis females is mediated by the combined presence of Camponotus femoratus ants and homopteran nymphs. Caterpillars are entirely entomophagous, and do not eat plant tissues. Alesa amesis caterpillars have distinct behaviors for feeding on their prey, and for soliciting and drinking honeydew secretions from homopteran nymphs. The leg lengths of entomophagous Alesa caterpillars are shown to be longer than phytophagous relatives. The legs of Alesa are used for prey handling and soliciting honeydew secretions. We suggest that elongation of the thoracic legs has been a general consequence of entomophagy in butterfly caterpillars. This study clarifies our understanding of A. amesis and its interactions with multiple species, and points to behavioral and morphological traits important to interpreting the evolution of entomophagy among caterpillars. Our observations establish the likelihood that other members of Eurybiini may be entomophagous, and suggest that entomophagy may have evolved independently among the Nymphi–diini and Eurybiini.
The Effect of Hurricane Iris on the Food Supply of Black Howlers (Alouatta pigra) in Southern Belize1
Authors: Pavelka Mary S. M. , Behie Alison M. 
Published: September 2010

ABSTRACTHurricanes frequently affect the forests of South and Central America; however, few studies have quantified their effects to forest structure, especially when concentrating on the food supply of an animal population. Hurricane Iris made landfall in Southern Belize on 8 October 2001, severely damaging a 52 hectare site where the behavioral ecology of a population of Central American Black Howlers (Alouatta pigra) had been under study for 2.5 yr. The hurricane resulted in a mortality rate of 35 percent for major food trees, which was primarily attributed to uprooting, snapping, and major delimbing. This damage accounted for 97 percent of the food tree loss between the two sample periods. Tree species differences were found in both the percentage loss and category of damage to food trees. Trees of different heights also experienced different percentage loss and levels of damage; subcanopy and emergent trees experienced higher loss than canopy trees, and subcanopy trees were frequently uprooted. This was partially attributed to a lack of buttressing on these subcanopy trees. Buttressing was found to decrease the frequency of uprooting. Tree size was the only factor that did not influence either damage or death. Trees from which fruit were eaten by black howlers died more than twice as often as did trees eaten for leaves.
Stilt Root Structure in the Neotropical Palms Iriartea deltoidea and Socratea exorrhiza1
Authors: Avalos Gerardo , Salazar Diego , Araya Ana L. 
Published: September 2010

ABSTRACTMany arborescent palms develop a stilt root cone that provides increased mechanical support on steep hillsides, better root aeration under waterlogged conditions, resprouting after mechanical damage, and rapid stem elongation. However, for most species the role of stilt roots is not well understood. We determined how palm size and slope inclination affected the structure of stilt roots in the neotropical palms Iriartea deltoidea and Socratea exorrhiza. We expected palm height to be lower on steep slopes because the effectiveness of root support could decrease as slope inclination increases, and thus, the structure of the root cone would vary mostly with slope. Alternatively, if stilt root development is determined by palm size, their production should match stem height, with taller palms having larger cones. We measured the stilt root cone of 31 Iriartea and 36 Socratea palms in San Ramón Biological Reserve and Golfito Wildlife Refuge, Costa Rica. We divided the cone into five variables (horizontal projections of the cone base and stilt root height up and down the slope, and width of the cone base), from which we extracted the first two principal components and used them to measure the effects of slope and palm size on stilt root structure. We found stilt roots to be determined by palm size, not by slope conditions. Stilt roots matched palm size, with larger palms having taller and larger cones, maintaining stability under diverse slope conditions.
Impact of Commercial Hunting on Monkey Populations in the Taï region, Côte d'Ivoire1
Authors: Refisch Johannes , Koné Inza 
Published: September 2010

ABSTRACTWe studied the impact of hunting on monkey species in the Taï National Park and adjacent forests in Côte d'Ivoire. The average wild meat consumption per capita per year was assessed from market surveys and interviews. We determined that the amount of primate wild meat being extracted in the Taï National Park and surrounding forests was 249 t in 1999. Hunting pressure was the highest on the larger primate species such as red colobus, Procolobus badius, black and white colobus, Colobus polykomos, and the sooty mangabey, Cercocebus torquatus atys. Estimates of population densities were based on line transect surveys. The maximum annual production of each species was calculated using the Robinson and Redford model (1991) and assuming unhunted conditions. Comparing current harvest levels with the maximum sustainable yield suggests that harvest of red colobus monkeys (Procolobus badius) is sustainable, whereas current off‐take of the black and white colobus (Colobus polykomos), the sooty mangabey (Cercocebus atys), diana monkeys (Cercopithecus diana), and Campbell's monkeys (Cercopithecus campbelli) exceeds sustainability by up to three times.
Crop Size and Fruit Neighborhood Effects on Bird Visitation to Fruiting Schefflera morototoni Trees in Puerto Rico1
Authors: Saracco James F. , Collazo Jaime A. , Groom Martha J. , Carlo Tomás A. 
Published: September 2010

ABSTRACTStudies of zoochorous seed dispersal systems often consider crop size, yet seldom consider the kinds and amounts of fruits surrounding parent plants (the fruit neighborhood) when attempting to explain among‐plant variation in fruit removal. We studied avian frugivory at 24 Schefflera morototoni trees from February to May 1998 in central Puerto Rico. The number of fruits removed by avian seed dispersers per visit was similar among focal trees (typically 2–4). In contrast, visitation rate was highly variable (range: 0–71 visits per 4 h). We used multiple regression analyses to evaluate the relative roles of crop size (focal tree ripe fruit abundance) and fruit neighborhood variables (measured within 30 m of focal trees) in affecting visitation to focal trees by avian frugivores. Visitation rate was positively related to crop size (although this variable was only significant in one of four regression models considered) and negatively related to the presence or abundance of conspecific fruits, suggesting that trees competed intraspecifically for dispersers. Relationships between visitation and heterospecific fruits were mixed—some kinds of fruits appeared to enhance visitation to focal trees, while others seemed to reduce visitation. In most regression models, neighborhood variables had larger effects on visitation than focal tree fruit crop size. Our results highlight the important effects of local fruiting environments on the ability of individual plants to attract seed dispersers.
Clearing Width and Movements of Understory Rainforest Birds1
Authors: Laurance Susan G. W. , Gomez Marcela S. 
Published: September 2010

ABSTRACTWe assessed the capacity of three species of disturbance‐sensitive understory birds to traverse a highway (50–75 m width) and large farm clearing (250 m width), by radio‐tracking translocated individuals in central Amazonia, Brazil. Most individuals translocated across the highway (eight of nine birds) or moved within continuous forest (five of seven birds) returned to their home ranges, whereas none of five birds moved across the large clearing returned. Our results suggest that large clearings (>250 m width) can significantly reduce the movements of some understory rainforest birds.
Survival, food consumption and growth of Norway lobster (Nephrops norvegicus) kept in laboratory conditions
Authors: MENTE Elena 
Published: September 2010

AbstractSuccessful commercial aquaculture of crustacean species is dependent on satisfying their nutritional requirements and on producing rapidly growing and healthy animals. The results of the present study provide valuable information for feeding habits and growth ofNephrops norvegicusL., 1758) under laboratory conditions. The aim of the present study was to examine food consumption, growth and physiology of the Norway lobsterN. norvegicusunder laboratory conditions.N. norvegicus(15 g wet weight) were distributed into 1001 tanks consisting of five numbered compartments each. They were fed the experimental diets (frozen mussels and pellets) for a period of 6 months. A group of starvedNephropswas stocked and fasted for 8 months. AlthoughNephropsgrew well when fed the frozen mussels diet, feeding on a dry pellet feed was unsatisfactory. The starvation group, despite the fact that showed the highest mortality (50%), exhibited a remarkable tolerance to the lack of food supply. The study offers further insight by correlating the amino acid profiles ofNephropstail muscle with the two diets. The deviations from the mussel's diet for asparagine, alanine and glutamic acid suggest a deficiency of these amino acids in this diet. The results of the present study showed that the concentrations of free amino acids are lower in relative amount than those of protein‐bound amino acids, except for arginine, proline and glycine. The present study contributes to the improvement of our knowledge on nutritional requirements of the above species.