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131.
Invasion by alien organisms is a common worldwide phenomenon, and many alien species invade native communities. Invasion by
alien species is especially likely to occur on oceanic islands. To determine how alien species become integrated into island
plant–insect associations, we analyzed the structure of tree–beetle associations using host plant records for larval feeding
by wood-feeding beetles (Coleoptera: Cerambycidae) on the oceanic Ogasawara Islands in the northwestern Pacific Ocean. The
host plant records comprised 109 associations among 28 tree (including 8 alien) and 26 cerambycid (including 5 alien) species.
Of these associations, 41.3% involved at least one alien species. Most native cerambycid species feed on host trees that have
recently died. Alien trees were used by as many native cerambycid species (but by significantly more alien cerambycid species)
as were native trees. Native cerambycid species used as many alien tree species (but significantly more native tree species)
as did alien cerambycids. Thus, we observed many types of interactions among native and alien species. A network analysis
revealed a significant nested structure in tree–cerambycid associations regardless of whether alien species were excluded
from the analysis. The original nested associations on the Ogasawara Islands may thus have accepted alien species. 相似文献
132.
1 Previous work had suggested that adult male click beetles (Agriotes spp.) show differential responses to species specific pheromone traps. This hypothesis was tested using mark–release–recapture methods to estimate the maximum sampling range and the effective sampling area of traps for three species. 2 Captured beetles of the species Agriotes lineatus, Agriotes obscurus and Agriotes sputator were marked to show the direction of release, the distance of the release point from the trap and the replicate. Analysis of variance showed that there were significant differences in recapture rates between species and release distances. There were no significant differences between release direction and replicates. 3 Calculated linear speeds suggested differences in movement rates in the order: A. lineatus > A. obscurus > A. sputator. There were also substantial differences between the species in the maximum sampling ranges and effective sampling areas of the traps. These placed the species in the same order. 4 The results are used to estimate the minimum cost of mass trapping programmes to prevent males from mating, giving values of €165/ha/year (A. lineatus), €247.5/ha/year (A. obscurus) and €2343/ha/year (A. sputator). 5 Implications for the use of pheromone traps in wireworm pest management are discussed. It is concluded that current U.K. recommendations based on the cumulative total catch of the three species over a sampling season can be improved by considering the spatial relationships between the adult trapping system and larval distribution. The current constraint to this is the general inability to separate wireworms into species. 相似文献
133.
Brice A. McPherson Nadir Erbilgin David L. Wood Pavel Svihra Andrew J. Storer Richard B. Standiford 《Agricultural and Forest Entomology》2008,10(4):315-321
1 Sudden oak death is caused by the apparently introduced oomycete, Phytophthora ramorum. We investigated the role of bark and ambrosia beetles in disease progression in coast live oaks Quercus agrifolia. 2 In two Marin County, California sites, 80 trees were inoculated in July 2002 with P. ramorum and 40 were wounded without inoculation. Half of the trees in each group were sprayed with the insecticide permethrin [cyclopropanecarboxylic acid, 3‐(2,2‐dichloroethenyl)‐2,2‐dimethyl‐(3‐phenoxyphenyl) methyl ester] to prevent ambrosia and bark beetle attacks, and then were sprayed twice per year thereafter. After each treatment, sticky traps were placed on only the permethrin‐treated trees. Beetles were collected periodically in 2003. 3 Inoculated trees accounted for 95% of all beetles trapped. The ambrosia beetles Monarthrum scutellare and Xyleborinus saxeseni and the western oak bark beetle Pseudopityophthorus pubipennis were the most abundant of the seven species trapped. 4 Permethrin treatment delayed initiation of beetle attacks and significantly reduced the mean number of attacks per tree. Beetles did not attack any wounded or noncankered inoculated trees. 5 Trees with larger cankers trapped more beetles early in the disease. Once permethrin lost effectiveness, the number of beetle entrance tunnels was a more reliable predictor of subsequent trap catch than was canker size. 6 Beetles were initially attracted to P. ramorum cankers in response to kairomones generated in the host‐pathogen interaction. After beetles attacked the permethrin‐treated trees, aggregation pheromones most probably were the principal factor in beetle colonization behaviour. 相似文献
134.
Ground beetles (Coleoptera: Carabidae) as bioindicators 总被引:23,自引:0,他引:23
One of the primary goals of research on bioindicators is to identifyspecies or other taxonomic units that would reliably indicate disturbances inthe environment, and reflect the responses of other species or the overallbiodiversity. However, there is no perfect bioindicator and selecting the mostsuitable one depends to a great extent on the goal of the survey. In this paperwe examine the suitability of carabids as bioindicators. Carabids are frequentlyused to indicate habitat alteration. They have been used in grasslands andboreal forests where species number and/or abundances have been noted to changealong a habitat disturbance gradient. A common trend is that large, poorlydispersing specialist species decrease with increased disturbance while smallgeneralist species with good dispersal ability increase. Some species are notaffected by moderate disturbance. There is, however, not enough research todetermine how suitable carabids are for biodiversity studies, or how well theyrepresent the response of other species. We conclude that carabids are usefulbioindicators, but as crucial understanding of their relationship with otherspecies is incomplete, they should be used with caution. 相似文献
135.
Responses of aquatic macrophytes to leaf herbivory may differ from those documented for terrestrial plants, in part, because
the potential to maximize growth following herbivory may be limited by the stress of being rooted in flooded, anaerobic sediments.
Herbivory on aquatic macrophytes may have ecosystem consequences by altering the allocation of nutrients and production of
biomass within individual plants and changing the quality and quantity of aboveground biomass available to consumers or decomposers.
To test the effects of leaf herbivory on plant growth and production, herbivory of a dominant macrophyte, Nymphaea odorata, by chrysomelid beetles and crambid moths was controlled during a 2-year field experiment. Plants exposed to herbivory maintained,
or tended to increase, biomass and aboveground net primary production relative to controls, which resulted in 1.5 times more
aboveground primary production entering the detrital pathway of the wetland. In a complementary greenhouse experiment, the
effects of simulated leaf herbivory on total plant responses, including biomass and nutrient allocation, were investigated.
Plants in the greenhouse responded to moderate herbivory by maintaining aboveground biomass relative to controls, but this
response occurred at the expense of belowground growth. Results of these studies suggest that N. odorata may tolerate moderate levels of herbivory by reallocating biomass and resources aboveground, which in turn influences the
quantity, quality and fate of organic matter available to herbivores and decomposers. 相似文献
136.
Abstract: Traces within traces is a new ichnological field that is meant to shed light on significative palaeoecological aspects. Dung beetle fossil brood balls ( Coprinisphaera ispp.), from the Middle Eocene – Lower Miocene Sarmiento Formation of Patagonia, Argentina, show two different trace fossils excavated in its infillings and/or wall that reveal the presence and relationships among different components of past dung communities. Tombownichnus pepei n. isp. is represented by elongated pits, circular to elliptical in cross-section, occurring in the centre or beside ovoid mounds in the internal surface of the Coprinisphaera wall. These traces record the activity of cleptoparasites, such as other dung beetles or flies, whose larvae were probably carried passively with the dung for provisions. Tombownichnus pepei would represent the pupation chambers excavated by full grown larvae in the Coprinisphaera wall after completing their development inside provisioned dung. The other trace fossil, Lazaichnus fistulosus is represented by circular to subcircular borings occurring in Coprinisphaera walls, in connection with an internal gallery in their infillings. Its connection also with meniscate burrows and chambers in the surrounding palaeosol attributable to aestivation chambers of earthworms revealed that these organisms would have been active cleptoparasites or detritivores in dung beetle fossil brood balls. 相似文献
137.
Shelly L. Thomas Robert G. Wagner William A. Halteman 《Biodiversity and Conservation》2009,18(9):2405-2419
In order to maintain biodiversity in forests, it has been recommended that harvests be designed after patterns of natural
disturbance. Using a long-term study that includes harvest treatments designed to emulate tree-fall gap disturbances in Maine’s
Acadian forest, we examined how the species richness, abundance, diversity, and assemblage similarity of click beetles inhabiting
coarse woody material (CWM) were affected by gap harvesting and CWM characteristics (diameter, degree of decay, and type of
wood). There were few differences in beetle assemblages between 0.07 and 0.12 ha harvest gap treatments. Four of the most
common species had higher abundances under a closed forest canopy than within harvest gaps. Species richness and total abundance
were higher in CWM that had larger diameters and were more decayed. Species assemblages also differed with the degree of wood
decomposition. Diversity was higher in CWM from softwood trees than hardwood trees. Results from this study suggest that small
(<0.2 ha) harvest gaps with living trees retained throughout the gap can maintain click beetle assemblages similar to that
of an unharvested forest. Forest managers also need to address the temporal continuity of CWM, including different types of
wood (hardwood and softwood), a range of decay conditions, and a range of diameter classes, especially larger diameters (>35 cm). 相似文献
138.
Calcrete aquifers in the arid Yilgarn region of central Western Australia are a biodiversity hotspot for stygofauna. A distinct pattern of interspecific size class variation among subterranean dytiscid beetle species has been observed in 29 of these aquifers where either two or three small, medium and/or large sympatric species are found that are in some cases sister species. We used a 3.5 km2 grid of bores to sample dytiscids on a fine-scale and employed a comparative phylogeographical and population genetic approach to investigate the origins of a sympatric sister species triplet of diving beetles from a single aquifer. Mitochondrial DNA sequence data from the Cytochrome oxidase c subunit I gene revealed that all three species have high levels of haplotype diversity with ancient (∼1 million years ago) intra-specific coalescence of haplotypes, but low levels of nucleotide diversity. Population analyses provide evidence for multiple expansion events within each species. There was spatial heterogeneity in the distribution of genetic variation and abundance both within and among the three taxa. Population analyses revealed significant fine-scale differentiation with isolation by distance for Paroster macrosturtensis and P. mesosturtensis , but not the smallest species P. microsturtensis . Haplotype network analyses provided limited or no evidence for past population fragmentation within the large and small species, but substantial historical divergence was observed in P. mesosturtensis that was not spatially structured. A patchy population structure with contemporaneous and historical isolation by distance in the three species is likely to have been a significant isolating and diversifying force, preventing us from ruling out a potential role for allopatric divergence during speciation of this beetle sister triplet. 相似文献
139.
C. M. HOUSE C. A. WALLING C. E. STAMPER A. J. MOORE 《Journal of evolutionary biology》2009,22(9):1961-1966
Male reproductive success generally increases with number of mates but this need not be true for females. If females are the limiting sex, as few as one mate can be optimal. Despite the theoretical differences driving multiple mating in the sexes, multiple mating is the norm rather than the exception. Empirical investigations are therefore required to determine why females mate with multiple males. Both nonadaptive (correlated responses to selection on males, given the mean mating rates have to be the same) and adaptive (direct or indirect fitness benefits) can drive the evolution of multiple mating in females. Females of the burying beetle Nicorphorus vespilloides often mate repeatedly with the same male, but this appears to be a correlated response to selection on males rather than reflecting direct benefits to females for multiple mating. However, an unexamined alternative to this nonadaptive explanation is that females benefit by mating with multiple different males and therefore are selected for general promiscuity. Here we examine if mating polyandrously provides fitness benefits by examing the effects of number of mates (1, 2 or 3), mating system (monogamous, polyandrous) and their interaction. The only significant influence was mating more than once. This did not depend on type of mating. We suggest that unlike most other species examined, in N. vespilloides mating with the same male repeatedly or with several different males reflects an indiscriminate willingness to mate as a result of correlated selection on males for high rates of mating. 相似文献
140.
Fourteen mite species in three genera of the family Macrochelidae were collected from the body surface of dung beetles (Scarabaeidae) in Mt Merapi National Park, Jogyakarta, Indonesia. Of these, three species, Macrocheles turgoensis n. sp., M. pumilus n. sp. and Glyptholaspis merapiensis n. sp., were described as new to science. The remaining 11 species were Glyptholaspis fimicola (Sellnick, 1931), Neopodocinum spinirostris (Berlese, 1910), M. dispar (Berlese, 1910), M. entetiensis Hartini and Takaku, 2005, M. hallidayi Walter and Krantz, 1986, M. jabarensis Hartini and Takaku, 2003, M. merdarius (Berlese, 1889), M. muscaedomesticae (Scopoli, 1772), M. oigru Walter and Krantz, 1986, M. sukaramiensis Takaku, 2001 and M. sp. aff. glaber (Müller, 1860). 相似文献