首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
Although many tropical savannas are highly influenced by humans, the patterns of biodiversity loss in these systems remain poorly understood. In particular, the biodiversity consequences of replacing native grasslands with exotic pastures have not been studied. Here we examine how the conversion of the native savanna grasslands affects dung beetle communities. Our study was conducted in 14 native (grassland: campo limpo), and 21 exotic (Urochloa spp. monoculture) pastures in Carrancas, Minas Gerais, Brazil. We collected 4996 dung beetle individuals from 66 species: 3139 individuals from 50 species in native pastures and 1857 individuals from 55 species in the exotic pastures. Exotic pastures had lower dung beetle richness, abundance and biomass than native pastures. Species composition between the two pasture types was significantly different and exotic pastures were dominated by few abundant species. Indicator species analysis detected 16 species indicators of native pastures and three of exotic pastures, according to relative abundance and frequency in each pasture system. Our results show that the conversion of native pastures to exotic pastures leads to a predictable loss of local species richness, increasing dominance and changes in species composition. These results highlight the importance of maintaining native pastures in the Cerrado agro‐pastoral landscape. Abstract in Portuguese is available at http://www.blackwell‐synergy.com/loi/btp .  相似文献   

2.
Factors affecting the light response of the riparian species Bembidion petrosum (Coleoptera: Carabidae) were studied with various experimental designs in laboratory and in field. B. petrosum, which lives in open gravely/stony sites, oriented towards directed light at higher temperatures (above 15.0°C). This positive phototaxis was replaced by an orientation towards a dark silhouette (screen) at low temperatures. The orientation towards silhouettes is mainly a simple type of form vision, although a fraction of the individuals seems to exhibit a negative phototaxis. In experiments with a dark zone and a zone with directed light, individuals of B. petrosum mainly selected the dark zone. However, if two stones were placed in the light part of the arena, individuals tended to hide under them. This applied independent of light intensity and whether a tuft of grass was present or absent in the dark part of the arena. The experiments indicate that the shift of the species between the reproduction (spring/summer) and hibernation (autumn/winter) habitat involves a change from an orientation towards silhouettes at low temperatures in autumn to an orientation towards directed light at higher temperatures in spring. This is combined with a specialized low thigmokinesis (preference of heavy and rough objects) and lower moisture requirements of the species in autumn/winter than in spring/summer.  相似文献   

3.
A survey of invertebrates on exposed riverine sediments (ERS) in four catchments of rivers in Scotland and northern England was carried out in 1996 and 1997 using pitfall traps. The resulting 179 lists of ground beetle species were used in ordination and classification analyses to determine the different types of habitats and the environmental factors influencing species assemblage distribution. Types of ERS habitat differed between highland and lowland catchments; there were also different numbers of habitat types in each catchment. The distribution of ERS within catchments was related to geology, position in catchment, sediment composition and the amount of vegetation. Evidence of the positive nature of river engineering was identified and the role of river management is discussed. The numbers of nationally rare and scarce ground beetle species recorded from the ERS habitats in each catchment are reported and the factors affecting their distribution discussed.  相似文献   

4.
In the present paper two genera and species,Rugiluclivina wrasei Balkenohl,1996,and Pseudoclivina memnonia(Dejean,1831),are reported in China for the first time.Morphological features and illustrations for the genera and species are provided.  相似文献   

5.
Carabus nitens, one of the most endangered ground beetles in Central Europe, was investigated with pitfall traps at 30 sampling sites in 17 heath fragments of the largest German heath landscape under nature conservation (nature reserve 'Lüneburger Heide'). The preference for damp Erica heaths and dry Calluna heaths in the building phase was thereby evident. Calluna heaths in the mature and degenerate phase, with and without extensive coverage by Avenella flexuosa, are either not inhabited or are avoided. The results of ovary dissections indicate that the populations in two successive spring seasons consisted mainly of animals which had already reproduced and were therefore older than one and a half years. Allozyme electrophoreses revealed variation for three of the nine investigated enzyme loci, and large differences in the allele frequency at one of these loci indicated genetic drift and fluctuations in the size of local populations. According to these results and statements in the literature, the loss of heathland areas and habitat quality are both responsible for the decline of the species. Suitable measures for preserving the species are (1) restoration of building phases of the Calluna heaths and (2) interconnection of at least the smaller heath fragments. Finally, recommendations are given for reintroductions.  相似文献   

6.
In the present paper two genera and species,Rugiluclivina wrasei Balkenohl,1996,and Pseudoclivina memnonia(Dejean,1831),are reported in China for the first time.Morphological features and illustrations for the genera and species are provided.  相似文献   

7.
Although most Carabidae are recognized as predacious, recent studies have shown that some tropical rain forest Carabidae use the small seeds of fallen fruit from some tree species as a key food resource (particularly figs [Moraceae] but also those from other families). Assemblages of carabid beetles (Coleoptera: Carabidae) at fruit falls of the Melastomataceae tree genera, Bellucia, Loreya, and Miconia, were studied in a terra firme rain forest near Manaus (Amazonia, Brazil) from February 1992 to August 1996. Of 5483 specimens of 14 carabid species collected at 53 fruit falls, 98.2 percent of the collected beetles represented the seed-feeding genus Notiobia. Four of the 7 Notiobia species were found to reproduce at Melastomataceae fruit falls. The most abundant species, N. glabrata, was found to be a Melastomataceae seed generalise while N. maxima seemed to prefer the seeds of Bellucia, and N. aulica and Af. umbrifera the seeds of Miconia. The presence of larvae indicated reproduction of N. glabrata at fruit falls of all three tree genera and reproduction of N. maxima at those of Bellucia. Fruit falls of different species and genera of Melastomataceae appeared to occur at different times of die year and not continuously throughout the year. The seed-feeding Notiobia species, which specialize on Melastomataceae, used fruit falls of figs as migratory “stepping stones” during periods when there were no Melastomataceae fruit falls. The comparable suite of fig seed-feeding specialist species of Notiobia did not appear to do the reverse and seemed to avoid Melastomataceae fruit falls. The carabid assemblage at fig fruit falls was more diverse than the assemblage at those of Melastomataceae. Among the Melastomataceae, carabid species richness was highest at Miconia fruit falls and lowest at Loreya fruit falls. The three most common predatory species caught at Ficus fruit falls were also caught at those of Melastomataceae and appeared to reproduce at both fruit fall types. The proportion of the carabid assemblage accounted by predatory species was much lower at Melastomataceae (1.8%) than at fig fruit falls (8%).  相似文献   

8.
We studied the role of red deer Cervus elaphus L. as ecosystem modifier in boreal forest (Tingvoll municipality, 62°52′ N, 8°20′ E, Norway), during early summer of 2001. The effect of grazing by red deer on ground beetles (Carabidae) abundance and diversity was investigated across a gradient of grazing pressures. We trapped ground beetles by pit-fall traps from three homogeneous winter grazing areas (ungrazed, medium grazed, heavily grazed). Bilberry Vaccinium myrtillus (the main winter food for red deer) was sampled and its dry weight was measured for the three locations. Gradient analyses showed that grazing by red deer affects carabid species composition. Grazing significantly affected the amount of bilberry, which correlated with species variation. According to our predictions, we found a higher abundance of carabids in the heavily grazed location, but the species richness and the diversity indices were similar for the three areas. This study shows that overall species composition is altered along a gradient as consequence of red deer winter grazing and that red deer act as ecosystem engineer, by reducing the bilberry heather which dominates the field layer in early summer.  相似文献   

9.
【目的】沟胸步甲属Holcoderus属于鞘翅目(Coleoptera)步甲科(Carabidae)壶步甲族(Lebiini)。本研究旨在对该属在中国分布的各个种进行分类厘定。【方法】基于中国科学院动物研究所的馆藏标本以及欧洲多家博物馆的模式标本,采用形态比较学方法开展研究。【结果】共发现中国沟胸步甲属5种,其中包括新种1种(双毛沟胸步甲H. bisetus sp. n.,模式产地:云南西双版纳),中国新纪录种3种(雅沟胸步甲H. gracilis、绿沟胸步甲H. smaragdinus和红腿沟胸步甲H. aeripennis)。提供了中国所有种类的形态描述及特征图,并编制了分种检索表。【结论】至此,我国所分布的沟胸步甲属物种从此前记录的1种增加至5种。  相似文献   

10.

Investigations were lead through in the years 1992 to 1995 at Halle (Saale) on a stand 24ha in size. Aim of the survey was to record the effects of graduate intensities of pest management on ground beetles. For this purpose 6 plots were installed on the field, 72 ‐ 200m each. Two plots served as control areas, without any application of pesticides. On two other plots intensive chemical pest management was applied. On the last two plots treatments were lead through considering the economic thresholds for weeds, fungal and insect pests according to the rules of integrated pest management. Ground beetles were sampled by using pitfall traps. In 1992 complementary methods to the pitfall trap catches, pick up of beetles after pesticide applications and semi-field-tests, on all plots were lead through. The graduate pest management was carried out 1992 and 1993 in winter wheat and 1994 in sugar beet stands. The last crop in 1995 was summer barley. In this year all plots were treated conventionally. In 1992 the differences between the total catches of ground beetles on the experimental sites were not high. In the following year most species were predominant on the control sites. In 1994 in sugar beet mechanical weed control was carried out on the control plots. The intensity of pesticide management between intensive and integrated plots differs only small. The amounts of ground beetles reached similar values on all experimental sites. In contrast to the expections the trap catches of ground beetles in the final investigations in summer barley were highest in the plots which had been treated integrated in the years before. The smallest amount was sampled in the former intensively managed sites. Renunciation of pesticides often is connected with economic losses which are not tolerable. If management is conducted considering the economic thresholds corresponding to the principles of integrated pest management negative effects on the economy of nature should not be expected for the longer term.  相似文献   

11.
记述采自中国广东始兴车八岭国家级自然保护区连唇步甲属Sofota1新种:黑连唇步甲Sofota nigrum,sp.mov.。模式标本保存在华南农业大学昆虫标本室。  相似文献   

12.
Six microsatellite loci were isolated from the ground beetle Carabus problematicus. The polymorphism ranged from two to 17 alleles and observed and expected heterozygosities ranged from 0.137 to 0.676 and 0.147 to 0.710, respectively.  相似文献   

13.
We isolated and characterized 10 microsatellite loci in the ground beetle Carabus nemoralis (Coleoptera, Carabidae), an ubiquist species largely distributed in Europe. Polymorphism ranged from 3 to 12 alleles on the 30 individuals from the same locality examined.  相似文献   

14.
Abstract. 1. Carabid beetles were sampled by means of pitfall traps on several clearcut areas and in adjacent forests.
2. A hierarchical analysis of diversity revealed a significant increase in the within-genus component of species diversity after forest cutting.
3. This trend in intrageneric diversity was obscured, with respect to total species diversity, by a nonsignificant reduction in diversity at the generic level.
4. The increase in the within-genus component of species diversity following forest cutting was consistent with the hypothesis that disturbance of a cornmunity can disrupt processes of competitive exclusion.  相似文献   

15.
We characterize six microsatellite loci from the ground beetle Carabus violaceus. The polymorphism of the loci was assessed in 46 individuals from one population. The number of alleles ranges between three and eight, and the observed heterozygosities between 0.46 and 0.76. All males are homozygous for locus CVI08106CMPG, whereas most females are heterozygous. This suggests that this locus is situated on the X chromosome. Tests in eight different species of ground beetles showed that four loci could be amplified in C. coriaceus and one each in C. glabratus, C. nemoralis, C. problematicus and Abax parallelepipedus.  相似文献   

16.
We compared the response of ground beetles (Coleoptera: Carabidae) to the creation of canopy gaps of different size (0.13, 0.26, and 0.50 ha) and age (1 and 7 years) in a bottomland hardwood forest (South Carolina, USA). Samples were collected four times in 2001 by malaise and pitfall traps placed at the center and edge of each gap, and 50 m into the surrounding forest. Species richness was higher at the center of young gaps than in old gaps or in the forest, but there was no statistical difference in species richness between old gaps and the forests surrounding them. Carabid abundance followed the same trend, but only with the exclusion of Semiardistomis viridis (Say), a very abundant species that differed in its response to gap age compared to most other species. The carabid assemblage at the gap edge was very similar to that of the forest, and there appeared to be no distinct edge community. Species known to occur in open or disturbed habitats were more abundant at the center of young gaps than at any other location. Generalist species were relatively unaffected by the disturbance, but one species (Dicaelus dilatatus Say) was significantly less abundant at the centers of young gaps. Forest inhabiting species were less abundant at the centers of old gaps than in the forest, but not in the centers of young gaps. Comparison of community similarity at various trapping locations showed that communities at the centers of old and young gaps had the lowest similarity (46.5%). The community similarity between young gap centers and nearby forest (49.1%) and old gap centers and nearby forest (50.0%) was similarly low. These results show that while the abundance and richness of carabids in old gaps was similar to that of the surrounding forest, the species composition between the two sites differed greatly.  相似文献   

17.
Labial and maxillary palps in 22 species of ground beetle larvae revealed the presence of four different types of sensilla: sensilla digitiformia, sensilla campaniformia, sensilla basiconica and sensilla chaetica. Using transmission electron microscopy techniques, the role of most of them was defined: sensilla campaniformia and sensilla chaetica are mechanoreceptors; while sensilla basiconica are chemoreceptors. Sensilla digitiformia can be both mechanoreceptors and chemoreceptors, though hygroreception may also be postulated on the basis of their abundance on the mouthparts of some hygrophilous species that depend on damp or wet patchy biotopes/seasons. The number and location of the sensory structures has been found to vary among the investigated taxa. The differences are related to the larval behavioural types, and are an adaptive response to different lifestyles, feeding habits and use of space.  相似文献   

18.
19.
Investigations concerned with ground beetle (Carabidae) dynamics in the agroecosystem have generally been limited to relatively short time periods in one crop, commonly wheat, whilst other studies have concentrated on the influence of landscape structure and non-crop habitat on beetle activity, again usually in one crop. Results of a seven-year survey at Nafferton in northern England, with recording from all crops in an organic rotation and from three types of field boundary, indicated that the lack of field boundary management had the greatest influence on ground beetle activity/density in this particular agroecosystem. However, within the crop rotation, grass/clover limited activity/density compared with that in cereal, potato and bean crops and there were also differences within cereal crops. Data from a 17-year survey at Drayton Environmental Change Network (ECN) site in midland England indicate that previous understanding of ground beetle activity and distribution in intensively managed landscapes may have been limited by temporal constraints. At Drayton, changes in surrounding crop cover, with the introduction of willow coppice and reduced area of arable land and agricultural inputs, considerably influenced ground beetle activity/density and assemblages in non-crop habitat. Small, active species dominating the assemblage in the first few years of the Drayton survey were gradually replaced by larger, non-flying species, especially after all the willow coppice had been planted. In both surveys, activity/density of ground beetles was related to disturbance, affecting vegetation cover and structure, but at the field scale at Nafferton and at the farm scale at Drayton. Longer surveys in a variety of landscapes such as those by the United Kingdom Environmental Change Network are likely to improve understanding of activity, diversity and distribution of invertebrates, which are fundamental requirements if predators such as ground beetles are required for ecosystem service provision.  相似文献   

20.
不同土地利用方式对河北坝上步甲物种多样性的影响   总被引:3,自引:0,他引:3  
王建芳  王新谱  李秀敏  刘桂霞 《昆虫学报》2010,53(10):1127-1134
为了探讨土地利用方式对步甲物种多样性的影响及其与环境因子的关系, 于2009年5-10月利用巴氏罐法, 对河北坝上塞北管理区内的灌草丛、马铃薯地、苜蓿地、围封草地、中度放牧草地和重度放牧草地6种生境的步甲进行了系统调查。结果表明: (1)共捕获步甲标本10 804号, 计10属18种, 其中强足通缘步甲Pterostichus fortipes、侧步甲Carabus latreillei和双斑猛步甲Cymindis binotata占优势, 个体数分别占总数的67.5%, 7.53%和7.06%。(2)苜蓿地中的步甲密度、物种丰富度、Margalef丰富度指数、Shannon-Wiener多样性指数和均匀度指数均较高, 其他样地较低。(3)聚类分析结果显示, 不同生境的步甲群落相似性与受干扰强度和土地利用方式一致。(4)步甲主要在6-9月活动, 高峰期为7-8月。各物种在不同土地利用方式生境内的季节变化趋势与不同生境植被生长季节相关, 步甲个体数量随着植物生物量的增加而增加。强足通缘步甲Pterostichus fortipes高峰期大多出现在植物生长旺盛的7月, 仅围封草地内的高峰出现在8月; 双斑猛步甲Cymindis binotata的高峰期出现在8-9月。(5)典范对应分析表明, 土壤含水量、土壤温度、植物盖度、植物生物量及植株高度是影响步甲群落组成的重要环境因子。结论认为, 不同土地利用方式对环境的干扰影响了步甲赖以生存的生境, 进而影响了其物种的组成和数量分布格局。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号