Interpreting and using outputs from the Canadian Forest Fire Danger Rating System in research applications

Understanding and being able to predict forest fire occurrence, fire growth and fire intensity are important aspects of forest fire management. In Canada fire management agencies use the Canadian Forest Fire Danger Rating System (CFFDRS) to help predict these elements of forest fire activity. In this paper a review of the CFFDRS is presented with the main focus on understanding and interpreting Canadian Fire Weather Index (FWI) System outputs. The need to interpret the outputs of the FWI System with consideration to regional differences is emphasized and examples are shown of how the relationship between actual fuel moisture and the FWI System’s moisture codes vary from region to region. Examples are then shown of the relationship between fuel moisture and fire occurrence for both human- and lightning-caused fire for regions with different forest composition. The relationship between rate of spread, fuel consumption and the relative fire behaviour indices of the FWI System for different forest types is also discussed. The outputs of the CFFDRS are used every day across Canada by fire managers in every district, regional and provincial fire management office. The purpose of this review is to provide modellers with an understanding of this system and how its outputs can be interpreted. It is hoped that this review will expose statistical modellers and other researchers to some of the models used currently in forest fire management and encourage further research and development of models useful for understanding and managing forest fire activity.

Rats on the run: removal of alien terrestrial predators affects bush rat behaviour

Predators can strongly influence the microhabitat use and foraging behaviour of prey. In a large-scale replicated field experiment in East Gippsland, Australia, we tested the effects of reduced alien red fox (Vulpes vulpes) and alien wild dog (Canis lupus familiaris) abundance (treatment) on native bush rat (Rattus fuscipes) behaviour. Bush rats are exposed to two main guilds of predators, namely mammalian carnivores and birds of prey. Tracking rat movements using the spool-and-line technique revealed that, in treatment sites, rats used ground cover, which provides shelter from predators, less often than at unmanipulated fox and wild dog abundance (non-treatment sites). In treatment sites, rats more frequently moved on logs where they would have been exposed to hunting foxes and dogs than in non-treatment sites. Furthermore, in treatments, rats showed a preference for understorey but not in non-treatments. Hence, bush rats adapted their behaviour to removal of alien terrestrial predators. Giving-up densities (GUDs) indicated no treatment effects on the marginal feeding rate of bush rats. Interestingly, GUDs were higher in open patches than in sheltered patches, suggesting higher perceived predation risk of bush rats during foraging at low versus high cover. The lack of treatment effects on GUDs but the clear response of bush rats to cover may be explained by the impact of predators other than foxes and wild dogs.     

Cryptic prey colouration increases search time in brown trout (<Emphasis Type="Italic">Salmo trutta</Emphasis>): effects of learning and body size

Little is known about how cryptic colouration influences prey search in near-surface aquatic habitats, although such knowledge is critical for understanding the adaptive value of colour crypsis as well as the perceptive constraints influencing foraging behaviour in these environments. This study had two main aims: (1) to investigate how background colour matching by prey affects foraging efficiency by brown trout parr and (2) to investigate how foraging ability on cryptic and conspicuous prey is affected by fish size at age (reflecting dominance). We addressed these questions by training wild brown trout parr to forage individually on live brown-coloured maggots on a cryptic (brown) or conspicuous (green) background. A separate experiment confirmed the absence of trout preference for brown or green substrate. The results show that prey background colour matching increases search time in brown trout. Search time generally decreased by learning, but conspicuous prey remained an easier prey to find throughout the six training trials. Thus, perceptive constraints appear to limit search efficiency for cryptic prey, suggesting that cryptic colouration can confer survival benefits to prey in natural environments. Smaller fish generally found conspicuous prey faster than larger individuals, whereas search time for cryptic prey was not influenced by body size. This suggests that smaller individuals compensate for inferior competitive ability by increasing foraging activity rather than improving cognitive ability. The technique of varying cognitive demands in behavioural tasks could be used more in future studies aimed at distinguishing motivational effects from cognitive explanations for variation in behavioural performance.     

Spawning behaviour and sex hormone levels in adult and precocious brown trout (Salmo trutta L.) males and the effect of anosmia

Summary. In the present experiment the behaviour and endocrine status of males of the brown trout, Salmo trutta L., (Salmoniformes: Salmonidae) were studied when males were kept in a stream tank with a nest digging female. Groups of mature adult males and precocious intact or anosmic male parr were placed with the nesting female so that the group resembled a natural spawning situation with big anadromous fish acting as dominant males and precocious parr acting as “sneakers”. A control experiment was also run with only males without a female present. In intact parr there were significant positive correlations between the per cent of the total observation time spent with a female, milt volume, and plasma concentration of 17α, 20β-dihydroxy-4-pregnen-3-one. Anosmic parr had significantly lower volumes of strippable milt and gonadal steroid hormone levels compared with intact parr. However, no differences were found in the control experiment. Significantly fewer anosmic parr attended and courted the nesting female and those anosmic fish that attended the female had significantly lower plasma levels of gonadal hormones. Intact parr also displayed a greater number of agonistic acts against other parr without any difference in fighting ability. No differences in aggression occured in the control experiment. In adult males together with a female, post-experimental gonadal steroid hormone levels were higher than pre-experimental levels. Positive correlations between aggression and androgen hormone levels were observed in adult males. No differences in plasma hormone levels were observed between adult males and intact precocious males. The results show that olfactory occlusion results in low steroid hormone levels and milt volumes in precocious males placed in a spawning situation. The courting behaviour was also affected by anosmia. Odours from the nesting female may have caused the enhanced plasma hormone levels and stimulated the males to attend the female. Received 15 May 1997; accepted 29 June 1997.     

Photochemical behaviour of musk tibetene

BACKGROUND: Synthetic musk compounds are widely used as additives in personal care and household products. The photochemical degradation of musk tibetene in aqueous solutions or in acetonitrile/water mixtures under different conditions was studied in order to assess its environmental fate. METHODS: Musk tibetene dissolved (or suspended) in water and/or acetonitrile/water mixtures was irradiated at different times by UV-light and by solar light. The irradiation mixtures were analyzed by NMR and TLC. The photoproducts formed were identified by GC-MS and NMR data. RESULTS: The experimental results indicated that musk tibetene was photodegradable in water or acetonitrile/water mixtures with half-life reaction times close to 20 minutes. The irradiation mixtures were separated by chromatographic techniques yielding three photoproducts (3,3,5,6,7-pentamethyl-4-nitro-3H-indole, 3,3,5,6,7-pentamethyl-4-nitro-1H-indoline and 3,3,5,6,7-pentamethyl-4-nitro-3H-indolinone) identified by means of spectroscopic analysis. DISCUSSION: The numerical modelling of the photodegradation concentration-time profiles gave (8.13 +/- 0.15) x 10(-2) and (1.34 +/- 0.04) x 10(-2) mol/E for the overall primary quantum yield of direct photolysis for musk tibetene and the major intermediate (3,3,5,6,7-pentamethyl-4-nitro-3H-indolinone), respectively, in the wavelength range 305-366 nm. The half-life times of photodegradation of the both substances varied from 1-1.5 hours at 20 degrees N during the summer season to 6-10 hours for highest latitudes in winter. CONCLUSIONS: Under solar light, musk tibetene was photolabile in acetonitrile and acetonitrile/water 1/1, while it was slowly degraded when suspended in water. In all media, musk tibetene was photodegraded into three photoproducts. By using a kinetic model, the overall primary quantum yields of direct photolysis of musk tibetene and its main photoproduct, in the wavelength range 305-366 nm, were estimated, indicating that the photodegradation rate for musk tibetene is faster than the photolysis rate of the major by-product. RECOMMENDATIONS AND PERSPECTIVES: The results indicate that, in order to assess the environmental impact of musk tibetene on the aquatic ecosystem, great attention should be focused on the major photoproduct which is proved to be more persistent than the parent compound under light irradiation. The predicted half-life times of direct photolysis for both substances ranged from 1-1.5 hours at 20 degrees N during the summer season to about 6-10 hours for highest latitudes in winter, indicating that, from a photochemical point of view, the environmental persistence of these substances increases by increasing the latitudes and during the cold seasons, making more realistic an intake of these xenobiotic molecules into the food chain of aquatic living organisms. Tanabe reports in his Editorial (Tanabe 2005) that "It is necessary to have knowledge of the global picture of synthetic musk pathways. So, it is conceivable that now is the time to study the transport, persistency, distribution, bioaccumulation and toxic potential of this new environmental menace on a global scale, especially in developing countries". Therefore, the future environmental analysis and investigations on the eco-toxicity of nitro musk compounds should take into account not only the presence of the parent compounds but also their photochemical intermediates or end-by-products.     

正确认识市场经济和“政府行为”的关系

环境监测是一项政府行为,如何在社会主义市场经济条件下,正确处理“政府行为”与市场经济的矛盾,已成为各级环保部门共同探讨并需要妥善解决的问题。本文根据经济学的有关理论,对环境监测这一领域在社会主义市场经济中所处的地位、作用做了全面的论述,并对如何理解环境监测“政府行为”提出看法和见解。     

高效液相色谱法测定水中微量酚

本文报道了水中11种微量酚的高效液相色谱测定方法。用氯化四丁基按作为阳离子对萃取剂。二氯甲烷章取水中微量酚，除本酚外，水中10种微量酚的回收率大于90％。用MicropakMCH－5色谱柱，醋酸—水—乙睛流动相，uv254um和280um双波长检测，流速1ml／min下，对水中11种微量酚进行了分离和定量、11种酚的检测极限是0.1mg／L～1.26mg／L；检测范围为0.1mg／L～7mg／L。对2—甲基—4，6—二硝基酚的峰高与浓度进行了线性回归，γ＝0.9993；该法适用于水中11种微量酚的同时测定。     

鸭绿江口的溶解无机氮

本文讨论了１９９６年５月鸭绿江溶解无机氮的含量和分布变化特征，并同其他一些河口作了比较，鸭绿江口ＮＯ３－Ｎ，ＮＯ２－Ｎ，ＮＨ４－Ｎ的平均含量分别为５０．３．０．４５和３．０５μｍｏｌ／Ｌ，而丹东上游鸭绿江支流瑗河下降的溶解无机氮浓度很高，达２０３．４μｍｏｌ／Ｌ，主要由农业施用氮肥大量从耕用地中流失所致。     

Immigration pattern and success in red squirrels

Summary We studied the characteristics of immigrants and the effects of immigration on reproductive activity and spacing behaviour in red squirrels living in high-quality woodlands. Male immigration peaked in spring, female immigration in autumn. There was no sex bias in dispersal distance of local recruits or in the proportion of male/female immigrants, but more subadults than adults immigrated on the study plots. Hence, hypotheses explaining sex-biased dispersal were irrelevant in explaining immigration patterns in our study populations. Immigrant females were not in breeding condition, nor had they produced a litter prior to immigration. Hence breeding dispersal did not occur. Red squirrels are promiscuous, and females defend intrasexual territories while males have overlapping home ranges with a dominance hierarchy (Wauters et al. 1990; Wauters and Dhondt 1992). Site fidelity is very important to reproductive success and most parents still have a high residual reproductive value after having produced a litter. Under such circumstances, the resident fitness hypothesis (RFH; Anderson 1989) predicts that parents can benefit by forcing emigration of offspring if the latter are likely to find nearby vacancies. The settlement pattern of successful immigrants, which had a higher probability of becoming established when they had high body mass and when they were settling in plots with reduced intrasexual competition, agreed with the RFH and with the proximate dispersal mechanism suggested by Gliwicz (1992), that dispersal tendency in both sexes depends on the degree of intrasexual competition under local conditions. The fact that close inbreeding was never observed could indicate that random immigration of both sexes, within the social environment of a partly territorial, relatively long-lived species, has evolved not only to reduce competition for resources between parents and offspring but also as an inbreeding avoidance mechanism. Correspondence to: L. Wauters     

Evolutionary aspects of perfume collection in male euglossine bees (Hymenoptera) and of nest deception in bee-pollinated flowers

Summary A fascinating pollination system has been evolved between perfume producing flowers and perfume collecting male euglossine bees in the neotropics. Detailed investigations have contributed to an understanding of the interactions between euglossine males and flowers as a pollination system. The role which the collected perfume plays in the reproductive behaviour of euglossine bees is not fully understood. A favoured hypothesis suggests that the collected fragrances are used as precursors for male sex pheromones and thus serve to attract conspecific males or females. It is not known how perfume collection behaviour evolved. Here, an evolutionary approach presents a new hypothesis which suggests that the evolution of perfume collection in euglossine males is based upon pre-existing signals which were attractive to females and males. It is further suggested that, at the evolutionary outset, flowers mimicked nest sites to deceive nest-seeking euglossine bees. In addition, a comparative study was undertaken on the phenomena of nest-mimicking flowers in related bee families.