Blowfly species composition in sheep myiasis in Scotland

Abstract Samples of dipteran larvae were collected from live sheep throughout Scotland, reared in the laboratory, and identified once adult flies emerged. Lucilia sericata was found in 77% of samples, and other species in 49%. The most common alternative species were L.caesar , which occurred in 31 % of samples, and Protophormia terraenovae , which occurred in 18%. Three other calliphorid species, Calliphora vomitoria, C.vicina and Lillustris , and the muscid Muscina pabulorum were also found. The proportion of samples containing alternative species was significantly lower in eastern Scotland than in western Scotland. Significantly higher proportions of samples containing alternative species were collected at altitudes of 200 m and above; from sheep of hill breeds; from rough grazing conditions and moorland; in the absence of trees; and in the presence of bracken.     

贺兰山岩羊冬春季取食生境的比较

2003年11～12月和2004年4～6月,在贺兰山设定了25条固定样线,采用直接观察法对岩羊冬春季的取食生境选择进行了研究。结果表明,岩羊冬季对12种取食生境生态因子有选择性,偏爱选择位于山地疏林草原带,优势乔木为灰榆,乔木密度〈4株、高度4～6m,灌木密度〉5株、高度〉1．3m,食物质量〉50g,人为干扰距离〈500m,距裸岩距离〈2m的地方取食。而春季对11种取食生境生态因子有选择性,偏爱选择山地疏林草原带,优势乔木为灰榆,乔木密度〈4株、高度〈6m,灌木密度5～10株、高度1．3～1．7m,食物质量〉100g,海拔高度〈2000m,距水源距离〈500m,隐蔽级50％～75％的地点。冬春季岩羊对植被类型、地形特征、优势乔木、乔木密度、乔木高度、灌木密度、灌木距离、食物丰富度、坡向、坡度、距水源距离、人为干扰距离和隐蔽级的选择存在显著差异。主成分分析表明,冬季第1主成分的贡献率达24．493％,其中绝对值较大的权系数出现在植被类型、优势乔木、乔木高度、乔木距离、灌木密度、灌木高度、海拔高度、距水源距离和人为干扰距离等生态因子：春季第1主成分的贡献率达28．777％,其中绝对值较大的权系数出现在植被类型、乔木距离、灌木高度、灌木距离、食物丰富度、海拔高度和人为干扰距离等生态因子。随着北方地区冬春季食物数量和质量的剧烈变化,贺兰山岩羊对取食生境的利用对策也将发生一定程度的改变,与其他分布区的岩羊相比,贺兰山独特的地理位置和特殊生境使其在取食生境选择上存在很大差异。     

Feeding habitats of blue sheep (Pseudois nayaur) during winter and spring in Helan Mountains, China

The feeding habitat selection of blue sheep (Pseudois nayaur)was studied by direct observation method in the Helan Mountains,China during winter (from November to December)and spring (from April to June)from 2003 to 2004.We established 25 line transects to collect information on feeding habitats used by blue sheep.Blue sheep in the study area preferred mountain savanna forests,a habitat dominated by Ulmus glaucescens,with medium tree density (＜4 individuals/400 m2),moderate tree height (4-6 m),higher shrub density (＞5 individuals/100 m2),higher shrub (＞1.3 m),higher food abundance (＞50 g),moderate distance to human disturbance (＜500 m),and mild distance to bare rock (＜2 m).Such habitats characterized by 12 ecological factors were preferred as feeding areas by blue sheep during winter.Similar to habitat selection by the species during winter,blue sheep also showed a preference for mountain savanna with tree dominated by Ulmus glaucescens and medium tree density (＜4 individuals/400 m2)during spring.Nevertheless,blue sheep preferred medium tree height (＜6 m),moderate tree density (5-10 individuals/100 m2),medium shrub height (1.3-1.7 m),higher food abundance (＞100 g),moderate altitude (＜2 000 m),moderate distance to water resource (＜500 m),and medium hiding cover (50%-75%)during spring.Selection of the feeding habitats by sheep showed a significant difference in vegetation type,landform feature,dominant tree,tree height,shrub density,distance to the nearest shrub,food abundance,slope direction,slope degree,distance to water resource,and hiding cover between winter and spring.Results of principal components analysis indicated that the first principal component accounted for 24.493%of the total variance among feeding habitat variance during winter,with higher loadings for vegetation type,dominant tree,tree height,distance to the nearest tree,shrub density,shrub height,altitude,distance to water resource,and distance to human disturbance.In spring,the first principal components explained 28.777%of the variance,with higher loadings for vegetation type,distance to the nearest tree,shrub height,distance to the nearest shrub,food abundance,altitude,and distance to human disturbance.     

急性低氧对高原土生动物藏系绵羊血气的影响

为了探讨急性低氧时藏系绵羊(Ovis aries)的血气特点,揭示其低氧适应机制,将7只雄性藏系绵羊和5只雄性移居绵羊分别置于高低压氧舱内,测定模拟海拔0、2 300和4 500 m时各动物清醒状态下的血气指标。用热稀释法测定心输出量。使用血气分析仪和EG7血样板,测定动脉及混合静脉血的血气指标,按Ficks方法计算氧耗量。结果显示,随着模拟海拔高度的升高,藏羊和移居羊的动静脉血氧饱和度(So2)、氧分压(Po2)、二氧化碳分压(Pco2)都呈明显下降趋势(P<0.05),血红蛋白浓度(Hb)、血液pH、心输出量及氧耗量虽无明显的差异性改变,但它们在4 500 m处的绝对值是增加的。在相同海拔,藏羊的Hb明显低于移居羊(P<0.05),4 500 m时藏羊的动脉血氧饱和度(Sao2)及组织摄氧量显著高于移居羊(P<0.05)。表明藏羊在急性低氧时表现出的高Sao2及高组织摄氧量,低Hb、低pH是它适应高原低氧的生理基础。     

Relationship of functional residual capacity to various body measurements in normal sheep.

Functional residual capacity (FRC) was determined by nitrogen washout in 55 normal sheep. Data on various external body measurements were collected which included body weight, chest circumference, chest width, body length, height, and sternum length. In addition, data on wet lung weight and wet lung weight/body weight ratio were collected on 10 of the sheep. A significant correlation was found between FRC and all measured parameters except height and sternum length. Multiple linear regression of all external body measurements showed the best correlation of FRC to body weight and body length, while the addition of chest circumference and/or chest width did not significantly improve the correlation. Significant deviation from the population was noted in three sheep (5.5%) that had lung weight/body weight ratios which were significantly lower than the rest of the population.     

Allometric and growth data of an evergreen oak, <Emphasis Type="Italic">Quercus glauca</Emphasis>, in a secondary broadleaved forest

The evergreen oak Quercus glauca often dominates secondary broadleaved forests in Western Japan. It is regarded as a mid-successional species, whose diameter and height growth fall between those of early- and late-successional species. Despite the ecological importance of this evergreen oak in the secondary succession of the evergreen broadleaved forest zone in Japan, tree-felling data that allow estimations of tree mass and leaf area from non-destructive measurements are lacking. This paper provides stem growth data, read from tree rings on disks sampled from 13 Q. glauca stems, and their allometric data. The samples were collected in 1994 from the Ginkakuji-san National Forest, Kyoto City, Japan. Allometric data comprised data on stem age, diameter at breast height, diameter at 10% height, tree height, height of the lowest living branch, height of the lowest living leaf in the crown, volume of the main stem, squared stem diameter just below the lowest living branch, total leaf area of the stem, dry weight of the total leaves, dry weight of all branches, dry weight of the main stem, total aboveground dry weight, mean relative photosynthetic photon flux density (PPFD) above the crown, mean relative PPFD below the crown, crown projection area, and specific leaf area. These data can be helpful for estimating the biomass and leaf area index of a Q. glauca stand by enabling the derivation of allometric relationships between non-destructive measurements (such as stem diameter at breast height, and tree height) and tree mass or leaf area. Diameters (including bark thickness) at ground height and above (at 0.5- or 1-m intervals) for each stem are also provided. Stem growth data were based on tree-ring reads from disks taken from heights of 0.0 and 0.3 m, and at 0.5-m (stem height <7 m) or 1.0-m (stem height ≥7 m) intervals above that. Stem volume growth derived from these tree-ring data can be converted into stem mass growth if combined with an analysis of the allometric data, which may serve as a useful resource for the estimation of carbon fixation by evergreen oaks in relation to global climate change.     

长白山红松不同树高处径向生长特征及其对气候的响应

利用长白山红松不同树高(0.3、1.3、4、10、15、20、25 m)处的径向生长资料,分析各树高处径向生长特征,建立红松生长与气候因子的相关关系,以期完善红松种群对气候变化的响应机制。结果表明:(1)红松不同树高处年径向生长量变化趋势基本一致,除在1980年前后,20 m处径向生长量出现异常增加外,其他各高度径向生长均出现下降趋势,红松基部和顶端(0.3、1.3 m和20 m)处径向生长年际变化更明显。随着树高增加,各处年径向生长率有所降低,0.3m处生长速率最大,且与10 m和15 m处径向生长差异显著(P < 0.05)。(2)不同树高处径向生长对气候因子的响应存在明显差异,10 m树高是红松径向生长对温度和降水响应差异的分界线。10 m以下红松径向生长主要受到生长季温度的负作用,尤其是4 m处,与当年生长季初期(4月和5月)温度显著负相关(P < 0.05)。0.3 m和1.3 m处径向生长分别与上年9月平均温度显著正相关(P < 0.05),当年6月平均和最高温度显著负相关(P < 0.05)。随着树高上升,降水对径向生长的促进作用增强,而温度对径向生长的作用也发生改变。10 m(含)以上则受到温度和降水的共同作用。10 m处径向生长对气候因子响应最敏感,受到当年生长季高温的抑制作用,还与上年和当年生长季末(9月)降水显著正相关(P < 0.05)。15 m处径向生长与上年9月最低温度和降水显著正相关(P < 0.05),而与当年5月月平均温度显著负相关(P < 0.05)。20 m处径向生长与当年3月月平均、最低和最高温度,当年7月月平均温度以及当年5月降水显著正相关(P < 0.05),而与当年1月降水显著负相关(P < 0.05)。     

Airborne pollen dispersal and survival on mount sutton (Canada)

Summary In order to find whether or not a pattern exist in both pollen concentration and viability along altitudinal transects, samples were collected volumetrically (VPPS) each 25 m, from 500 to 825 m, on Mount Sutton (45°04N; 72°32W) (970 m). Both minimum concentration and minimum viability were found at 725 m. Airborne pollen viability was species dependent, while airborne concentrations were not specific. Sampling height influence was also investigated volumetrically (BPS), by comparing paired samples at ground and 10 m levels. Again, pollen concentration pattern was found quite stable, while viability was found to be more height influenced, particularly at 725 m. The 725 m hinge altitude is located just above the June Mean Cloud Base altitude (657 m).     

Passage of uncharged dextrans from blood to lung lymph in awake sheep

To examine how molecular size alone influences the passage of macromolecules from the pulmonary microcirculation into lymph collected from the caudal mediastinal lymph node of the sheep, we infused polydisperse uncharged [3H]dextrans intravenously at a constant rate over a period of 7.5 h in nine awake sheep with lung lymph fistulas. Lymph and plasma were collected during hours 5.5-7.5 of the infusions, and the [3H]dextrans were separated by molecular sieve chromatography into fractions that ranged from 1.6 to 8.4 nm in effective molecular (Stokes-Einstein) radius. Lymph-to-plasma (L/P) ratios for [3H]dextrans were near 1.0 at 1.6-nm radius, decreased with increasing molecular size, and approached zero at radii above 5.0 nm. We confirmed that these L/P ratios represented steady-state values by extending the duration of the infusion to approximately 30 h in two of the nine sheep and finding that the L/P ratios remained unchanged. These results were consistent with molecular sieving through a homoporous membrane with cylindrical pores of 5.0-nm radius. We also found that the L/P ratio for albumin [0.76 +/- 0.13 (SE)] in five of the same sheep was much higher than that for the [3H]dextran fraction of the same effective molecular radius [0.11 +/- 0.02 (SE)]. These results suggest that the movement of macromolecules from the pulmonary microcirculation into pulmonary lymph collected from the caudal mediastinal node of the sheep is influenced by both molecular size and molecular charge and that, compared with uncharged dextrans, the steady-state passage of anionic endogenous proteins from plasma to lymph is enhanced.     

Feeding habitats of blue sheep (Pseudois nayaur) during winter and spring in Helan Mountains, China

The feeding habitat selection of blue sheep (Pseudois nayaur) was studied by direct observation method in the Helan Mountains, China during winter (from November to December) and spring (from April to June) from 2003 to 2004. We established 25 line transects to collect information on feeding habitats used by blue sheep. Blue sheep in the study area preferred mountain savanna forests, a habitat dominated by Ulmus glaucescens, with medium tree density (<4 individuals / 400 m²), moderate tree height (4–6 m), higher shrub density (> 5 individuals / 100 m²), higher shrub (> 1.3 m), higher food abundance (> 50 g), moderate distance to human disturbance (< 500 m), and mild distance to bare rock (< 2 m). Such habitats characterized by 12 ecological factors were preferred as feeding areas by blue sheep during winter. Similar to habitat selection by the species during winter, blue sheep also showed a preference for mountain savanna with tree dominated by Ulmus glaucescens and medium tree density (< 4 individuals / 400 m²) during spring. Nevertheless, blue sheep preferred medium tree height (< 6 m), moderate tree density (5–10 individuals / 100 m²), medium shrub height (1.3–1.7 m), higher food abundance (> 100 g), moderate altitude (< 2 000 m), moderate distance to water resource (< 500 m), and medium hiding cover (50%–75%) during spring. Selection of the feeding habitats by sheep showed a significant difference in vegetation type, landform feature, dominant tree, tree height, shrub density, distance to the nearest shrub, food abundance, slope direction, slope degree, distance to water resource, and hiding cover between winter and spring. Results of principal components analysis indicated that the first principal component accounted for 24.493% of the total variance among feeding habitat variance during winter, with higher loadings for vegetation type, dominant tree, tree height, distance to the nearest tree, shrub density, shrub height, altitude, distance to water resource, and distance to human disturbance. In spring, the first principal components explained 28.777% of the variance, with higher loadings for vegetation type, distance to the nearest tree, shrub height, distance to the nearest shrub, food abundance, altitude, and distance to human disturbance. Translated from Zoological Research, 2005, 26(6): 580–589 [译自: 动物学研究]     

TRAP CATCHES OF MUSCA VETUSTISSIMA WALKER (DIPTERA: MUSCIDAE) AND OTHER ARTHROPODS ASSOCIATED WITH CATTLE DUNG IN RELATION TO HEIGHT ABOVE GROUND LEVEL

Abstract
Catches of male and female Musca vetustissima in isolated fly traps located up to 3 m above ground were inversely related to height, but sex ratios and female age-distributions were similar for catches at all heights. Since the effect of height on log catch was highly significant, traps must be operated at a standard height to obtain estimates of fly abundance that are comparable between sampling occasions. Seasonal variation in log catch in relation to height was also highly significant, but was small in comparison to the effects of height. Catches of other dung-frequenting arthropods in pitfall traps were highest at ground level. Very few arthropods were caught in traps located 2 m or more above ground.     

Vertical distribution of epiphytic bryophytes and lichens emphasizes the importance of old beeches in conservation

During storms in 2005, a number of beech trees fell over at Biskopstorp, SW Sweden, offering the opportunity to study epiphytes along entire stems. In total 16 beech trees in four beech stands representing three different age classes were included. For each tree, 2 m segments from the base to the top were surveyed. In total 115 species were found (76 lichens, 39 bryophytes), of which 30 were considered to be of conservation concern (22 lichens, 8 bryophytes). For lichens significantly more species were recorded above 2 m in height, whereas more bryophytes were recorded below 2 m in height. Certain red-listed lichens were recorded only above 2 m in height on old trees. In a second data set from the same area 140 age-determined beech trees were surveyed for species of conservation concern at the heights 0–2 and 2–5 m, respectively. These species were found almost exclusively on old beech trees, and presence at 2–5 m was recorded, with one exception, only on those trees which also had species of conservation concern at 0–2 m. Records of these species correlated significantly to microhabitat variables, i.e. the presence of rough bark and moss cover higher up the stems on the old trees. This study indicates that surveying only the base in really old beech forests can underestimate both the number of species of conservation concern and their population sizes. However, surveys restricted to the base in rather even-aged beech stands catch a large proportion of the trees with species of conservation concern.     

Efficacy of bird-baited traps placed at different heights for collecting ornithophilic mosquitoes in eastern Queensland, Australia

To compare the efficacy of bird-baited traps with standard CO₂-baited Centers for Disease Control (CDC) light traps for collecting ornithophilic mosquito species, seven Latin square trials were conducted at six urban sites in Cairns and Brisbane, Australia. Traps were placed 1 m above ground level and 5–10 m according to tree canopy height. CO₂-baited CDC traps consistently collected more mosquitoes of all species than the bird-baited traps at all locations. In Brisbane, CO₂-baited CDC traps placed at ground level collected significantly more Culex annulirostris Skuse than those at canopy height during two trials, and more Aedes vigilax (Skuse) and Ae. procax (Skuse) during one trial each. Conversely, in Cairns, CO₂-baited CDC traps placed in the tree canopy collected significantly more Cx. squamosus (Taylor) during two trials, and significantly more Aedeomyia catasticta Knab and Cx. cubiculi Marks during one trial each. Consistently low yields of ornithophilic species including Cx. australicus Dobrotworsky & Drummond and Cx. quinquefasciatus Say in all traps tested suggests the need to employ alternative trapping measures to target these species in urban areas.     

Vertical stratification of beetles in tropical rainforests as sampled by light traps in North Queensland,Australia

How arthropods are distributed within the vertical structure of tropical rainforests is of considerable interest to ecologists. Here, we examine how light trapped beetles are distributed in tropical rainforest in North Queensland, Australia. In January and July 2012, traps were suspended 0 m, 10 m, 20 m and 30 m above the ground in five locations with no more than one trap at any single location on any night. Maximum canopy height at the sites was 35 m. A total of 7299 individuals of 492 morphospecies and 66 families were collected. The species abundance‐based coverage estimator predicted a total species richness of 765. Sample completeness decreases with increasing height from the ground suggesting higher strata were less well sampled. Distance‐based redundancy analysis showed species richness was significantly different between 30 m and all other levels but not between other paired strata. In contrast, both species composition and family composition were significantly distinct for all strata pairs except 10 m with 20 m, and 20 m with 30 m, suggesting that the most distinct strata were 0 m and 30 m. The first two axes of ordination and hierarchical clustering accounted for 46.5% and 17.4% of species composition variation corresponding with season and stratum, respectively. Family level analyses gave similar results to those at the species level. We found stratification of different feeding guilds with herbivores comprising a larger percentage of species in higher strata, whereas saprophages were restricted to the lower strata, reflecting the availability of key resources for these guilds. Fewer species or families were found to be indicators of strata, as measured using IndVal, than for Malaise and flight interception traps (FIT). Dytiscidae and Hydraenidae were abundant but had not been collected using Malaise and FIT. Which species or families are indicators of strata depends on sampling method suggesting multiple sampling methods should be used to establish indicators.     

Effects of space allowance on the grazing behaviour and spacing of sheep

In each of two experiments, four groups of 10 female Scottish Blackface sheep grazed for 2 weeks at each of four space allowances, according to a Greco-Latin Square design. Space allowances were 80, 100, 133 or 200m(2) per head in Experiment 1 and 50, 67, 100 or 200m(2) per head in Experiment 2. Confounding of space allowance and grazing pressure was avoided by the use of a rotational grazing system. Mean distances between sheep were measured from video recordings and distances expected by chance were calculated from simulations in which sheep were located within plot areas using randomly selected co-ordinates.Total time spent grazing was higher at 200m(2) per head and less at 50m(2) per head than at other space allowances, but there was no evidence for an effect of space allowance on herbage intake or digestibility, biting rate or the proportion of grazing time spent in ingestive behaviour. At space allowances from 50 to 133m(2) per head, there were no significant differences between mean observed inter-animal distances and those expected by chance, but observed values were lower than expected values at 200m(2) per head. At all space allowances, mean observed distances between sheep and their nearest neighbours were lower than distances expected by chance.The results show that, on relatively high quality, homogeneous vegetation, female Scottish Blackface sheep will graze at space allowances between 50 and 200m(2) per animal with no evidence of repulsion between individuals and with no clear evidence of grouping until space allowance reaches 200m(2). It is concluded that the relationship between grazing time and space allowance may reflect the extra activity required to maintain group cohesion as space allowance increases.     

The new record of the highest distribution altitude of cyprinid fishes in the world

Three specimens of Herzensteinia microcephalus (Cyprinidae: Schizothoracinae) were collected from the Chalaiburkun Chu, a headwater of Dri Chu of the southern tributaries of the Yangtze River. The sampling site is located at an altitude of 5,350 m above sea level in the North Slope of the Tanggula Mountain on the Qinghai-Tibet Plateau. This is a new highest distribution record of cyprinids, perhaps of all fishes in the world. This new altitude record increases approximate 150 m in vertical height than that in previous studies, which would largely expand the distribution area of H. microcephalus and its habitats. The distribution uplift of H. microcephalus might be an ecological response to recent glacial retreats on the Qinghai-Tibet Plateau. The data provide empirical evidence that climate change very likely has caused significant shifts in alpine fish distributions.     

Vertical oviposition activity of mosquitoes in the Atlantic Forest of Brazil with emphasis on the sylvan vector,Haemagogus leucocelaenus (Diptera: Culicidae)

This study aimed to assess the vertical patterns of oviposition and temporal changes in the distribution of mosquito species in an area of the Atlantic Forest in Rio de Janeiro State, Brazil, and in particular, the behavior and oviposition of potential yellow fever virus vectors. Mosquito samples were collected from the Ecological Reserve Guapiaçu (REGUA, Brazil), which includes a somewhat disturbed forest, with a large diversity of plants and animals. In all, 5,458 specimens (ten species from seven genera) were collected. Haemagogus leucocelaenus was the most frequently captured species, representing 73% of the specimens collected. Species richness and diversity were the highest in the samples collected from the ground‐level ovitraps and decreased with height. Species composition also differed significantly among heights. The largest species differences were detected between ovitraps set at the ground level and those set at 7 m and 9 m; Hg. leucocelaenus, Limatus durhamii, and Limatus paraensis contributed most to these differences. Sampling month and climatic variables had significant effects on species richness and diversity. Species diversity and richness decreased with height, suggesting that the conditions for mosquito breeding are more favorable closer to the ground. Species composition also showed vertical differences.     

Telemetric monitoring of fetal blood pressure and heart rate in the freely moving pregnant sheep: a feasibility study

Remote telemetric monitoring of fetal haemodynamics in pregnant sheep would allow unrestricted animal movement, minimize suffering and distress, and improve animal welfare, while enhancing the quality of data collected. This may also be useful in clinical practice following fetal surgery. Using an open fetal surgical technique at approximately two-thirds of gestation, we implanted the catheter of a D70-PCTP haemodynamic telemetric device (Data Sciences International, Tilburg, The Netherlands) into the carotid artery of the fetal sheep (n = 4). The attached transmitter was secured to the posterior aspect of the maternal anterior abdominal wall. Two receivers, with a range of 1 m each, were sited in an 11 m2 sheep enclosure to maximize animal freedom while allowing continuous monitoring of the ewe. The receivers were connected by cable to a nearby computer. In the first two procedures, both fetuses died eight and 12 days after surgery, and the catheter tip was observed to be lying in the bicarotid trunk. In the next two procedures the catheter tip was threaded further upstream from the insertion point, in an attempt to reach the fetal aorta, and both fetuses survived until the scheduled postmortem examination at the end of pregnancy. After catheter implantation, fetal blood pressure (BP) and heart rate (HR) were successfully recorded continuously for seven days and then hourly per day for a further three weeks. The fetal BP and HR values were in the normal range for healthy sheep fetuses.     

Formation and vertical distribution of sapwood and heartwood in Cryptomeria japonica D. Don

The formation and vertical distribution of sapwood and heartwood were studied with a 45-year-old Cryptomeria japonica D. Don. The tree was grown at a plantation with 1.5 m × 3.0 m spacing near Miao-Li, Taiwan and was felled on 27 February 1992. The thickness of sapwood and heartwood was expressed by a ring count and a linear measurement. The east-west (E-W) wood strips were collected from 0.3 m above ground upwards to the top of the tree at 2.5 m intervals. The sapwood thicknesses from the base to the 10.3 m tree level height are around 20–22 growth rings and 42±2 mm. At the top of the tree, the sapwood thickness is narrower. The heartwood, which decreases in thickness with increasing tree level heights is not found at the top of the tree. The heartwood appears as a conical shape in the tree trunk. There is no statistical difference in sapwood/heartwood thickness between E-W aspects. Tree level heights and the tree level age were found to be important parameters in determining the thickness of sapwood/heartwood.     

Distribution of airborne Mycosphaerella graminicola inoculum at the field scale

A network of 10 Burkard 7-day spore-recording traps was set up in the Walloon region in Belgium to monitor the airborne inoculum of wheat pathogens. Three spore traps were used to analyse the distribution of Mycosphaerella graminicola inoculum at the field scale, at 1 m above ground level. Two traps were set up in a wheat field 100 m apart. The third trap was placed 70 m away in a sugar beet field adjacent to the wheat field. Total DNA from each fragment of spore trap tape corresponding to 1 day sampling was extracted and the quantity of M. graminicola was assessed using real-time polymerase chain reaction (PCR) assay. The experiment was conducted from July to October 2009. Positive detections were obtained for between 33 and 36 days, depending on the spore traps. When detected, the daily quantities of cDNA, collected from a volume of 14.4 m3, fluctuated between 4.84E+00 and 6.10E+03. Correlation coefficients higher than 0,82 and no significant differences were observed between the quantities of M. graminicola collected by the three spore traps, indicating that, at 1 m above ground level, the distribution of inoculum can be considered as homogenous at the tested field scale. This study confirms that spore traps coupled with real-time PCR could be used to assess the airborne inoculum of M. graminicola and to understand the development of the disease at this scale.