Monitoring the European pine sawfly with pheromone traps in maturing Scots pine stands

Abstract

• 1 During 1989–93, field studies were conducted in Finland to develop a method based on pheromone traps to monitor and forecast population levels of the European pine sawfly (Neodiprion sertifer Geoffr.) and tree defoliation.
• 2 Three traps per site were baited with 100 µg of the N. sertifer sex pheromone, the acetate ester of (2S,3S,7S)‐3,7‐dimethyl‐2‐pentadecanol (diprionol), in maturing pine stands in southern and central Finland. In addition, three different dosages (1, 10 and 100 µg) of the pheromone were tested in 1991–92.
• 3 The highest number of males was observed in traps baited with the highest dose. On average, there was a 10‐fold increase in trap catch between lure doses.
• 4 Density of overwintering eggs was used to evaluate the effectiveness of pheromone traps in predicting sawfly populations. The proportion of healthy overwintering eggs was determined each year. A model based on the number of current shoots on sample trees, diameter at breast height and tree height was formulated to estimate eggs per hectare.
• 5 Linear regression analysis produced high coefficients of determination between number of males in traps and density of total eggs in the subsequent generation, when populations were at peak densities. The relationships were not significant for low population densities. The results indicate a risk of moderate defoliation when the seasonal trap catch is 800–1000 males per trap or higher.

     

A dispersal-aggregation model for mountain pine beetle in lodgepole pine stands

In this paper a dispersal-attack theory for bark beetle attacking trees is developed from a set of simple assumptions, and the resulting theoretical model is fit to data from four epidemic studies. Implications of the theory are discussed in relation to the dynamics of lodgepole pine-mountain pine beetle interactions.     

Cytogenetic monitoring of petrochemical workers

The frequencies of chromosomal aberrations and sister-chromatid exchanges (SCEs) in the peripheral blood lymphocytes of 360 persons, 180 workers in a petrochemical corporation and 180 appropriate controls, were studied. A significant increase in chromosomal aberrations and SCEs, compared to the control group, was observed in two sewage-treatment workshop workers; however, there were no significant differences between petrochemical workers from four workshops and a control group.     

Ectomycorrhizae and ectomycorrhizal fungal fruit bodies in pine stands differentially damaged by pine wilt disease

We surveyed ectomycorrhizae, ectomycorrhizal fungal fruit bodies, and soil physical properties in one heavily damaged and two lightly damaged pine stands on Mt. Tsukuba, central Japan. The rate of ectomycorrhizal root tips was not different between heavily and lightly damaged pine stands. For ectomycorrhizae, Cenococcum geophilum had high relative abundance in the heavily damaged pine stand. The number of ectomycorrhizal fungal fruit bodies in the heavily damaged pine stand was much lower than that in the lightly damaged pine stands.     

残次油松林群落特征与生物多样性恢复

在河北省兴隆县雾灵山国家级自然保护区研究了经长期人为破坏的残次油松林的群落特征及其在不同保护年限下的生物多样性恢复规律。研究表明,与正常林分相比,残次林的物种多样性指数大幅度降低,物种数量显著减少。在植物和昆早群落各参数的变化中,以灌木和天敌昆虫类群受影响最大,其科数分别减少５５．５６％和６０％,科－种多样性指数分别减少３０．１％和６０．７２％。     

Mating disruption of the pine sawfly Neodiprion sertifer (Hymenoptera: Diprionidae) in isolated pine stands

• 1 Previous applications of the mating disruption technique to Neodiprion sertifer resulted in decreased numbers of males caught in the treated area but no effect on sex ratio or overall population density.
• 2 The present study assessed the efficacy of mating disruption against N. sertifer outbreaks in pine stands surrounded by agricultural areas or pasture, and therefore isolated from other infested areas.
• 3 Pine stands were treated by placing dispensers with an erythro‐mixture of the acetate ester of 3,7‐dimethyl‐2‐pentadecanol every 10 m in a grid.
• 4 The efficacy of this technique was evaluated by comparing the number of males caught in sticky traps baited with synthetic pheromone, and by comparing the sex ratio and the population density of the sawfly in the subsequent generation between treated and control pine stands.
• 5 The number of males caught within treated areas was significantly lower than in the control area.
• 6 In the treated pine stands 46% of the egg clusters resulted in male cocoons only, compared to 3% of the clusters in the control stand.
• 7 A significant reduction of the sawfly population was observed in the treated pine stands. The results contrast to the earlier mating disruption attempts with N. sertifer and can probably be ascribed to the isolation of the experimental stands.

     

Structural patterns and biodiversity in burned and managed Aleppo pine stands

Increasing anthropic pressure is making forest fires more frequent in the Mediterranean Basin and therefore affecting the response of native flora and fauna. Two large fires occurred in summer, 1994, in the Southeastern Iberian Peninsula. Aleppo pine, the main tree species, regenerated naturally after the fire. In this study we are interested in strategies for maximizing Aleppo pine tree recovery and conservation of its ecosystem. We performed thinning and pruning in the pine tree stands 5 and 10 years after the fire and took measurements on structural patterns and plant diversity using several indices. In addition, we measured macro-lichen and faunal diversity indirectly. Results show significant differences between treated-burned plots and untreated-unburned plots. The plots thinned 10 years after the fire and the unburned plots (mature stands) showed a regular, non-aggregated distribution and a low diameter differentiation. Also, these plots showed similar plant diversity values. The silvicultural treatments did not significantly affect the fauna and lichen index values. The high intensity of thinning and late pruning applied to young Aleppo pine stands improved the structural pattern and plant diversity.     

Carbon sequestration in boreal jack pine stands following harvesting

A large area of boreal jack pine (Pinus banksiana Lamb.) forest in Canada is recovering from clear‐cut harvesting, and the carbon (C) balance of these regenerating forests remains uncertain. Net ecosystem CO₂ exchange was measured using the eddy‐covariance technique at four jack pine sites representing different stages of stand development: three postharvest sites (HJP02, HJP94, and HJP75) and one preharvest site (OJP). The four sites, located in the southern Canadian boreal forest, Saskatchewan, Canada, are typical of low productivity jack pine stands and were 2, 10, 29, and 90 years old in 2004, respectively. Mean annual net ecosystem production (NEP) for 2004 and 2005 was ?137±11, 19±16, 73±28, and 22±30 g C m^?2 yr^?1 at HJP02, HJP94, HJP75 and OJP, respectively, showing the postharvest jack pine stands to be moderate C sources immediately after harvesting, weak sinks at 10 years, moderate C sinks at 30 years, then weak C sinks at 90 years. Mean annual gross ecosystem photosynthesis (GEP) for the 2 years was 96±10, 347±20, 576±34, and 583±35 g C m^?2 yr^?1 at HJP02, HJP94, HJP75, and OJP, respectively. The ratio of annual ecosystem respiration (R) to annual GEP was 2.51±0.15, 0.95±0.04, 0.87±0.03, and 0.96±0.03. Seasonally, NEP peaked in May or June at all four sites but GEP and R were highest in July. R at a reference soil temperature of 10 °C, ecosystem quantum yield and photosynthetic capacity were lowest for the 2‐year‐old stand. R was most sensitive to soil temperature for the 90‐year‐old stand. The primary source of variability in NEP over the course of succession of the jack pine ecosystem following harvesting was stand age due to the changes in leaf area index. Intersite variability in GEP and R was an order of magnitude greater than interannual variability at OJP. For both young and old stands, GEP had greater interannual variability than R and played a more important role than R in interannual variation in NEP. Based on year‐round flux measurements from 2000 to 2005, the 10‐year stand had larger interannual variability in GEP and R than the 90‐year stand. Interannual variability in NEP was driven primarily by early‐growing‐season temperature and growing‐season length. Photosynthesis played a dominant role in the rapid rise in NEP early in stand development. Late in stand development, however, the subtle decrease in NEP resulted primarily from increasing respiration.     

Needle analyses and graphic vector analyses of Norway spruce and Scots pine stands

 The aims of this study were to test the nutritional condition of young stands of Norway spruce and Scots pine in southernmost Norway, where atmospheric inputs of anthropogenic nitrogen and strong acids, as well as deposition of magnesium by sea spray, are relatively high. There has been general concern about forest health in this region, specifically about nutrient deficiencies and nitrogen saturation caused by the atmospheric pollution. To expand our knowledge about these subjects, needle analyses and graphic vector analyses, as well as tree vigour index and height growth response to fertiliser application, were used as diagnostic tools. The overall conclusion is that phosphorous limitation is probably more frequent than expected in the coastal zone of southern Norway, especially in spruce on shallow soils. It is hypothesised that phosphorous limitation might be a more general problem or will arise as one in a 30 – 60 km coastal zone stretching from southernmost Sweden along the coast to the north and then westwards along the south coast of Norway. Nitrogen saturation in southernmost Norway might already occur on some sites with shallow soils. Needle analyses and graphic vector analyses can yield erroneous results if stress factors other than nutrient supply, e. g. severe drought, determine the growth rate of trees. In addition, the graphic vector analyses require that nutrients applied to the test plots are available to roots early in the growing season, and that needle nutrient concentrations in late autumn reflect those when the needles were formed. Received: 30 May 1995/Accepted: 27 December 1995     

Cytogenetic monitoring of industrial radiographers using the micronucleus assay

Industrial radiography is the process of using either gamma-emitting radionuclide sources or X-ray machines to examine the safety of industrial materials. Industrial radiographers are among the radiation workers who receive the highest individual occupational radiation doses. To assess occupationally induced chromosomal damage, we performed the cytokinesis-block micronucleus (CBMN) assay in peripheral lymphocytes of 29 male industrial radiographers, exposed to ionizing radiation for 12.8 years±11.2, in comparison with 24 gender-, age-, and smoking habits-matched controls. The CBMN assay was combined with fluorescent in situ hybridization with a pan-centromeric DNA probe in 17 exposed subjects and 17 controls randomized from the initial populations. The mean cumulative equivalent dose, recorded by film dosimeters, was 67.2 mSv±49.8 over the past 5 years. The mean micronucleated binucleated cell rate (MCR) was significantly higher in the industrial radiographers than in the controls (10.7‰±5.2 versus 6.6‰±3.1, P=0.009); this difference was due to a significantly higher frequency of centromere-negative micronuclei (C−MN) in exposed subjects than in controls (8.5‰±4.9 versus 2.2‰±1.6, P<0.001). The two populations did not significantly differ in centromere-positive micronuclei (C+MN) frequency. These findings demonstrate a clastogenic effect in lymphocytes of industrial radiographers. MCR significantly positively correlated with age in the two groups. After correction for the age effect, MCR did not correlate with duration of occupational exposure. No correlation between radiation doses and MCR, C−MN, and C+MN frequencies was observed. In addition to physical dosimetry records, the enhanced chromosomal damage in lymphocytes of industrial radiographers emphasizes the importance of radiation safety programs.     

皖东松树纯林与复层混交林比较研究

通过对皖东地区松树纯林和零星分布的复层林的调查,比较了单纯林和复层林的材积生长以及林地土壤理化性质的改善情况,研究了林内的光环境和庇荫下的林木的生理生态特性,认为建立充分发挥森林多种效益的人工复层林施业体系是该地区林业经营的方向．     

Cytogenetic monitoring of industrial radiographers using the micronucleus assay

Industrial radiography is the process of using either gamma-emitting radionuclide sources or X-ray machines to examine the safety of industrial materials. Industrial radiographers are among the radiation workers who receive the highest individual occupational radiation doses. To assess occupationally induced chromosomal damage, we performed the cytokinesis-block micronucleus (CBMN) assay in peripheral lymphocytes of 29 male industrial radiographers, exposed to ionizing radiation for 12.8 years+/-11.2, in comparison with 24 gender-, age-, and smoking habits-matched controls. The CBMN assay was combined with fluorescent in situ hybridization with a pan-centromeric DNA probe in 17 exposed subjects and 17 controls randomized from the initial populations. The mean cumulative equivalent dose, recorded by film dosimeters, was 67.2 mSv+/-49.8 over the past 5 years. The mean micronucleated binucleated cell rate (MCR) was significantly higher in the industrial radiographers than in the controls (10.7 per thousand +/-5.2 versus 6.6 per thousand +/-3.1, P=0.009); this difference was due to a significantly higher frequency of centromere-negative micronuclei (C-MN) in exposed subjects than in controls (8.5 per thousand +/-4.9 versus 2.2 per thousand +/-1.6, P<0.001). The two populations did not significantly differ in centromere-positive micronuclei (C+MN) frequency. These findings demonstrate a clastogenic effect in lymphocytes of industrial radiographers. MCR significantly positively correlated with age in the two groups. After correction for the age effect, MCR did not correlate with duration of occupational exposure. No correlation between radiation doses and MCR, C-MN, and C+MN frequencies was observed. In addition to physical dosimetry records, the enhanced chromosomal damage in lymphocytes of industrial radiographers emphasizes the importance of radiation safety programs.     

Tree response and mountain pine beetle attack preference,reproduction and emergence timing in mixed whitebark and lodgepole pine stands

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Cytogenetic monitoring of the population from ecologically unfavorable regions]

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Cytogenetic monitoring of fishermen with environmental mercury exposure

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Soil carbon stabilization in jack pine stands along the Boreal Forest Transect Case Study

Boreal forests, containing >20% of the total organic carbon (OC) present at the surface of the Earth, are expected to be highly vulnerable to global warming. The objective of this study was to compare soil OC stocks and chemistry in jack pine stands located along a latitudinal climatic transect in central Canada. Total OC stocks (0–1 m) increased with decreasing mean annual temperature (MAT). We used a combination of physical fractionation of soil OC pools, ¹³C isotopic determination and cross‐polarization, magic‐angle spinning ¹³C nuclear magnetic resonance (NMR) spectroscopy to further characterize OC composition at all sites. Soil OC was dominated by labile pools. As illustrated by the C/N ratios, δ¹³C data and results from the ¹³C NMR analysis, the light fraction showed little alteration within the soil profiles. Instead, this fraction reflected the importance of fresh litter inputs and showed an increase in root contribution with depth. As opposed to the light fraction, the clay‐ and silt‐stabilized OC exhibited an increase in δ¹³C and a decrease in C/N with depth, indicating an increase in its degree of decomposition. These changes with depth were more marked at the southern than the northern sites. Results hence suggest that if the MAT were to increase in the northern boreal forest the overall jack pine soil OC stocks would decrease but the remaining OC would become more decomposed, and likely more stabilized than what is currently present within the soils.