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61.
Lucas Battisti Michele Potrich Everton Ricardi Lozano Claudia Bueno dos Reis Martinez Silvia Helena Sofia 《Journal of Applied Entomology》2023,147(1):1-18
Bees are declining worldwide, and the use of pesticides has been linked to this problem. Studies show that even herbicides can negatively impact bees, causing death or compromising health. As a result, concern about the use of glyphosate (GLY) has increased, as it is the most sold pesticide. Studies have shown that exposure of bees to GLY can trigger sublethal effects. Considering the speed with which information is published, reviews become important for the integration of knowledge, aiding understanding of the topic. Therefore, the present study aimed to review the literature on the sublethal effects of GLY and the different commercial formulations on bees. After the literary review, it was observed that the exposition, acute and chronic, of larvae and adults of social and solitary bees, to GLY and its formulations, can trigger alterations in gene expression, enzyme functioning, oxidative metabolism, cell/tissue structure, intestinal microbiota diversity, learning, food consumption, flight and vertical displacement capacity, circadian cycle and body development of these insects. The most used species in the studies was Apis mellifera L. Studies are still necessary to understand the sublethal effects of GLY on bees, in the medium and long term, on colony homeostasis, especially about the information on the toxicity of some surfactants present in the different commercial formulations. 相似文献
62.
MORTALITY OF SEA OTTERS IN PRINCE WILLIAM SOUND FOLLOWING THE EXXON VALDEZ OIL SPILL 总被引:1,自引:0,他引:1
Abstract: This paper presents an estimate of the total number of sea otters that died as a direct consequence of the oil spill that occurred when the T/V Exxon Valdez grounded in Prince William Sound, Alaska on 24 March 1989. We compared sea otter counts conducted from small boats throughout the Sound during the summers of 1984 and 1985 to counts made after the spill during the summer of 1989. We used ratio estimators, corrected for sighting probability, to calculate otter densities and population estimates for portions of the Sound affected by the oil spill. We estimated the otter population in the portion of Prince William Sound affected by the oil was 6,546 at the time of the spill and that the post-spill population in the summer of 1989 was 3,898, yielding a loss estimate of approximately 2,650. Bootstrapping techniques were used to approximate confidence limits on the loss estimate of about 500–5,000 otters. The wide confidence limits are a result of the complex scheme required to estimate losses and limitations of the data. Despite the uncertainty of the loss estimate it is clear that a significant fraction of the otters in the spill zone survived. We observed otters persisting in relatively clean embayments throughout the oil spill zone suggesting that the highly convoluted coastline of Prince William Sound produced refuges that allowed some sea otters in the oil spill area to survive. 相似文献
63.
Paul Savary Jean-Christophe Foltête Hervé Moal Gilles Vuidel Stéphane Garnier 《Molecular ecology resources》2023,23(7):1574-1588
In connectivity models, land cover types are assigned cost values characterizing their resistance to species movements. Landscape genetic methods infer these values from the relationship between genetic differentiation and cost distances. The spatial heterogeneity of population sizes, and consequently genetic drift, is rarely included in this inference although it influences genetic differentiation. Similarly, migration rates and population spatial distributions potentially influence this inference. Here, we assessed the reliability of cost value inference under several migration rates, population spatial patterns and degrees of population size heterogeneity. Additionally, we assessed whether considering intra-population variables, here using gravity models, improved the inference when drift is spatially heterogeneous. We simulated several gene flow intensities between populations with varying local sizes and spatial distributions. We then fit gravity models of genetic distances as a function of (i) the ‘true’ cost distances driving simulations or alternative cost distances, and (ii) intra-population variables (population sizes, patch areas). We determined the conditions making the identification of the ‘true’ costs possible and assessed the contribution of intra-population variables to this objective. Overall, the inference ranked cost scenarios reliably in terms of similarity with the ‘true’ scenario (cost distance Mantel correlations), but this ‘true’ scenario rarely provided the best model goodness of fit. Ranking inaccuracies and failures to identify the ‘true’ scenario were more pronounced when migration was very restricted (<4 dispersal events/generation), population sizes were most heterogeneous and some populations were spatially aggregated. In these situations, considering intra-population variables helps identify cost scenarios reliably, thereby improving cost value inference from genetic data. 相似文献
64.
《Fungal Ecology》2023
We investigated which of the following environmental factors: the number of years since the windthrow of the tree (the age of dead wood), the phytocenosis (the type of forest community), altitude, exposure, wood hardness and the spatial scale of forest disturbances (small gaps with a few fallen spruces vs large-area windthrows) contributed to the diversity and abundance of lichens inhabiting the exposed wood of windthrown spruce trees in Polish Western Carpathian forests. Both Shannon H index and sum of coverage coefficients rose with increasing age of the wood, levelling off after 11–14 y (diversity) and 14–17 y (abundance). This factor appeared to be the most important for this group of lichens, but the significant positive impact of large-area windthrows on the lichen abundance was also demonstrated by using a GLM model. The age of the wood we precisely determined on the basis of data on Norway spruce mortality collected annually in permanent plots of the Gorce National Park since 2000. Using the Shore durometer we linked the course of the wood-inhabiting lichen succession with wood decay more precisely than before. The largest number of species was associated with medium hard wood, i.e., 51 < x ≤ 80 on the Shore scale. Based on the NMDS analysis, we distinguished four age groups of logs, differing in lichen abundance and defined by the dominance of distinctive species. A large number of usually corticolous lichen species used the wood of windthrown spruce logs as an optional habitat to survive large-scale, post-hurricane forest disturbances. 相似文献
65.
David H. Jewson 《Journal of phycology》1992,28(6):856-866
Studies of the life cycle of a centric diatom, tentatively identified as Stephanodiscus neoastraea Håkansson & Hickel, showed that sexual reproduction occurred every year in a freshwater lake (Lough Neagh, Northern Ireland). Male and female gametes were produced in cells below 55% of the maximum diameter during a 3–4-week period in late summer, following the return of nitrate concentrations above 10 μM NO3-N. The frequency of sexual reproduction was linked to the cycle of diameter size reduction and regeneration. The times of largest decreases in cell diameter were during nutrient stress in summer and low light conditions in late autumn, rather than during the main spring growth period. So, environmental conditions (combined with the limited life-spans of individual cells) affected the rate of diameter reduction and, therefore, the length of the life cycle (3–4 years). 相似文献
66.
Daniel E. L. Promislow 《Evolution; international journal of organic evolution》1991,45(8):1869-1887
Here, I use published mortality data from 56 natural populations of mammals to examine evidence for senescence, an increase in the probability of mortality with age. Data on extent of senescence and life history characteristics are compared across taxa in an attempt to test theories for the evolution of senescence in natural populations. In accord with theoretical expectation, senescence is highest in short-lived species with short generation times. In contrast to theoretical expectation, however, senescent increases in mortality rate do not begin until well after age at maturity in most cases. I also present evidence in support of the hypothesis that senescence will be lower in large-brained taxa. 相似文献
67.
P.C. Maris N.N. Joosten R.W. Goldbach & D. Peters 《Entomologia Experimentalis et Applicata》2004,113(3):149-155
The effect of thrips resistance in pepper (Capsicum annuum L.) – previously shown to result in impeded thrips population development (Maris PC, Joosten NN, Goldbach RW & Peters D (2003a) Restricted spread of Tomato spotted wilt virus in thrips‐resistant pepper. Phytopathology 93: 1223–1227. Maris PC, Joosten NN, Goldbach RW & Peters D (2003b) Spread of Tomato spotted wilt virus and population development of Frankliniella occidentalis in pepper resistant to thrips. Proceedings of the Section Experimental and Applied Entomology Netherlands Entomological Society (NEV) Amsterdam 14: 95–101.) – on thrips’[Frankliniella occidentalis Pergande (Thysanoptera: Thripidae)] reproduction, mortality, host preference, and behaviour was investigated. Reproduction, studied by oviposition and larval survival, was negatively affected by the thrips‐resistant (TR) phenotype, whereas the offspring's developmental rate did not differ on TR and the thrips‐susceptible (TS) phenotype. While thrips’ behaviour was hardly affected by thrips resistance, a significant preference for TS plants over the TR plants was found in different tests. When released on either a TR or a TS plant, thrips dispersed at significantly higher rates from the TR plants, demonstrating that not only an impeded reproduction, but also a reduced residence time adds to the reported lower thrips numbers on TR plants. 相似文献
68.
青海湖裸鲤寄生舌状绦虫的空间格局研究 总被引:3,自引:0,他引:3
舌状绦虫裂头蚴只寄生在体长小于220mm的青海湖裸鲤中,其种群在宿主种群中呈聚集分布。其聚集分布的强度随寄生虫种群平均密度的增加而降低。由于舌状绦虫在宿主体腔生长,产生明显的空间拥挤效应,可能导致宿主死亡或被食鱼鸟类捕食而转移到终末宿主中。在体长小于120mm的宿主中,密度依赖的死亡过程可能是使聚集强度降低的原因;而体长140-200mm的鱼中,则是非密度依赖的全死过程使聚集强度增加. 相似文献
69.
I. W. J. Debyser 《International journal of primatology》1995,16(6):889-907
I review literature on juvenile mortality of captive prosimians in order to evaluate the available information on captive
breeding. Juvenile mortality includes abortion, premature mortality, stillbirth, and death of the unweaned young. Prosimian
juvenile mortality ranges between 25 and 45% in captive populations. It is generally lower in the Lemuroidea, particularly
the Cheirogaleidae, than in the Lorisoidea. Mortality is particularly high in the Lorisinae. Most mortality, including a high
stillbirth rate, occurs on the first day and during the first 10 days thereafter. Stress, maternal neglect and traumatic insults,
not infrequently linked to each other, are the most frequently reported causes of death. The percentage of congenital malformations
tends to be high in some colonies. Sex of the infant and parity seem to be important risk factors for juvenile mortality,
whereas litter size does not appear to be important. Based on few data, wild- caught females appear to have higher breeding
success than those born in captivity. Synchronized births in lemuroids and isolated births in Galagoare more likely to result in successfully weaned infants. 相似文献
70.
Ülo Niinemets 《Trees - Structure and Function》1997,11(7):420-431
The relationship between stand biomass production, and tree age and size is generally a curve with a maximum. To understand
why wood production decreases in the final stages of stand development, the influence of increasing tree size on foliage chemical
composition and substrate requirement for foliage construction in terms of glucose [CC, g glucose (g dry mass) –
1] was investigated in the evergreen conifer Picea abies (L.) Karst. Because it was already known that irradiance affects both foliage morphology and chemistry in this species, and
it was expected that the foliage in large overstory trees would intercept on average more light than that in saplings in understory,
irradiance was measured in the sampling locations and included in the statistical models. CC of needles increased with increasing
total tree height (TH) and was independent of relative irradiance. A major reason for increasing CC with increasing TH was
a greater proportion of carbon-rich lignin in the needles in large trees. However, lignin did not fully account for the observed
changes in CC, and it was necessary to assume that certain other carbon-rich secondary metabolites such as terpenes also accumulate
in the foliage of large trees. Enhanced requirements for needle mechanical strength as evidenced by greater lignin concentrations
in large trees were attributed to increased water limitations with increasing tree height. Because water relations may also
control the sink capacities for assimilate usage, apart from the mechanical requirements, they may provide an explanation
for the accumulation of other energetically expensive compounds in the needles as well. Biomass partitioning within the shoot
was another foliar parameter modified in response to increasing tree size. The proportion of shoot axes, which serve to provide
needles with mechanical support and to supply them with water, decreased with increasing TH. This may limit water availability
in the needles, and/or manifest a lower water requirement of the needles containing proportionally more supporting and storage
substances, and consequently, less physiologically active compounds such as proteins. Probably the same factors which caused
CC of the needles to depend on TH, were also responsible for greater CC of the shoot axes in larger trees. These results collectively
suggest that increasingly more adverse water relations with increasing tree size may provide a mechanistic explanation for
the decline in foliar biomass and its functional activity during stand ageing.
Received: 9 April 1996 / Accepted: 14 January 1997 相似文献