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791.
Cells of the roots ofA. yokoscense growing on metalliferous habitats were fractionated into their cell wall and cytoplasmic components. About 70–90% of the
total copper, zinc and cadmium was located in the cell wall. Copper had a markedly greater affinity for the cell wall than
zinc and cadmium, and was prevented from entering the cytoplasm. A large proportion of these heavy metals in the cell wall
were exchanged as ions. The capacity of the cell wall for exchanging metal ions inA. yokoscense was higher than in other plants growing on metalliferous habitats. However, compared with different ferns unable to grow
on metalliferous habitats, this capacity was not unique toA. yokoscense. Consequetly, the root cell wall ofA. yokoscense is considered to be an important site of metal ion storage and may play the role of an excretory organ for heavy metals.
On the other hand, as proportion of the heavy metls was transported to the cytoplasm, where the metal content was much higher
than the average for normal ferns. This would suggest thatA. yokoscense has another metabolic mechanism related to metal tolerance. 相似文献
792.
Insects usually have cryptic colors to avoid detection by visually hunting predators. However, if the insects acquire toxic or repellent substances against predators, some of them develop conspicuous coloration to exhibit their unpalatability. Such warning colors allow insects to survive. In the nine-spotted diurnal moths (Erebidae: Arctiinae: Syntomini), we found the above-ground pupating species to have conspicuous colored pupae, but the ground-surface pupating species to have cryptic colored pupae. In this study, the relationships between unpalatability and coloration of these pupae are examined among three species of Amata and one species of Syntomoides. Pupae of the two species (A. germana and A. flava) are conspicuous in their color pattern with seven black dotted lines longitudinally on their pale-yellow bodies. These pupae are exposed to the aerial predators in a coarse silk mesh hanging from leaves and/or branches. The other two species (A. fortunei and S. imaon) pupate in spaces under stones, fallen twigs and leaves on the ground surface, and the pupae in a coarse silk cocoon is cryptic dark brown. Their pupation site selections are reproduced in the rearing glass vessels. Palatability assessment using lizards as a potential predator suggests that pupae of A. germana, A. flava and A. fortunei are unpalatable and the lizard's feeding response decreases with experience. However, pupae of S. imaon are all eaten (palatable). Finally, the possible evolutionary scenario of pupal colors of these four species is discussed in relation to pupation site selection and palatability. 相似文献
793.
794.
795.
Fabiane S. Annibale Richard J. Wassersug Denise de C. Rossa-Feres Fausto Nomura Cinthia A. Brasileiro Ariadne F. Sabbag Yu Zeng Jackson R. Phillips 《Austral ecology》2023,48(5):855-876
Two of the most fundamental questions in tadpole biology, also applicable to most small, under-studied organisms are: (1) ‘Why are they built the way they are?’ and (2) ‘Why do they live where they do?’ Regrettably, despite significant progress in most aspects of tadpole biology, the answers to these questions are not much better now than they were in the last century. We propose that an autecological approach, that is the careful observation of individuals and how they interact with the environment, is a potential path towards a fuller understanding of tadpole ecomorphology and evolution. We also discuss why more attention should be given to studying atypical tadpoles from atypical environments, such as torrential streams, water-filled cavities of terrestrial plants and wet rock surfaces neighbouring streams. Granted, tadpoles are rare in these settings, but in those unusual habitats the physical environments can be well described and characterized. In contrast, the more common ponds where tadpoles are found are typically too structurally complex to be easily delineated. This makes it difficult to know exactly what individual tadpoles are doing and what environmental parameters they are responding to. Our overall thesis is that to understand tadpoles we must see exactly what they are doing, where they are doing it, and how they are doing it. This takes work, but we suggest it is feasible and could greatly advance our understanding of how anuran larvae have evolved. The same strategies for studying tadpoles that we encourage here can be applied to the study of many other small and fast-moving animals. 相似文献
796.
The loss of butterfly diversity in north-western Europe has been studied extensively but much less is known about the status of other macrolepidoptera. The present paper presents results of the research on mainly day-flying larger moths carried out by Dutch Butterfly Conservation in The Netherlands. Research started in 1992 with a public campaign and a mapping programme, leading to an increase in the number of records of macrolepidoptera. Results from the mapping programme on day-flying moths showed a strong general decrease in The Netherlands, comparable with the loss of butterfly diversity. Transect counts have been undertaken since 2000 for a few species and this method is sufficient to measure trends over time if the moth densities are high enough. Another research component was to focus on marshland habitats in The Netherlands. Fifty-five characteristic marshland moth species were selected and the relative abundance of nearly all these species has declined. These trends were compared with four other countries in the Atlantic biogeographical zone. The relative abundance of the majority of marshland moths in The Netherlands was found to be higher than those in other European countries, so that The Netherlands has a special responsibility for the conservation of the moths of its marshes. Moreover, we emphasise that, next to butterflies, moths can be of great use in nature conservation because of their potential significance as indicator species in endangered habitats. 相似文献
797.
Marcia González-Teuber Alejandro Urzúa rea Morales Cristian Ibá?ez Luisa Bascu?án-Godoy 《Journal of Plant Ecology》2019,12(2):264
Aims
Desertification is a major concern in arid and semi-arid regions globally. Understanding interactions between vulnerable plant species and associated microbial symbionts may have important applications for conservation and restoration strategies in affected areas. 相似文献
798.
One of the key purposes of conservation selection strategies is to design a network of sites to support relevant biodiversity components and, therefore, decrease the risk of populations becoming isolated. To this end, it is important to be aware of the habitat locations of the target species and the threats of human activities, in order to identify areas of a high conservation priority. This paper takes the Chaharmahal and Bakhtiari province (Iran) as a case study, to highlight a network optimization for six target species of conservation concern, including the Persian leopard, Panthera pardus Pocock, wild sheep, Ovis orientalis Gmelin and wild goat, Capra aegagrus Erxleben. To run the optimization, we first generated the following input data: we modelled suitable habitats, using the InVEST model (Integrated Valuation of Environmental Services and Tradeoffs) and simulated the ecological impact of road networks (Spatial Road Disturbance Index (SPROADI), Kernel Density Estimation (KDE) and the Landscape Ecological Risk Index (ERI)). A visual inspection of the input data revealed that a large percentage of the study area constitutes a suitable habitat for the target species, however, the disturbances caused by the road demonstrate that the central and north-eastern regions of the study area are significantly affected. Indeed, approximately 10% and 25% of the study area are in the high and medium risk categories, respectively. Optimization using Marxan, shows that the north-western and southern regions of the study area should be given high conservation priority, necessary for an efficient conservation network. Habitats located in the north-central region should act as stepping-stone areas or corridors between the isolated regions in the north-east and the well-connected areas in the north-west and south. Overall, the findings of the present study show that the current network of protected areas is not contradictory to that suggested by Marxan, but has deficiencies in terms of size and stepping-stones. 相似文献
799.
Luís Fernando de Abreu Pestana Felipe Martello Renata Cristina Batista Fonseca 《Austral ecology》2023,48(4):743-760
Plantation forests substitute natural habitats and have rotation cycles of 7 years due to their high growth rates. This variation reflects on local and landscape changes, influencing habitat availability and affecting mammal communities. In this study, our general hypothesis was that the richness and composition of mammals varied in eucalyptus plantations in relation to native forest patches and in relation to the age of eucalyptus plantations. We predicted that (1) there would be lower mammalian richness and compositional differences in eucalyptus plantations compared to native vegetation due to monocultures having simplified environmental characteristics and (2) predicted that the richness and composition would vary according to eucalyptus age and that the highest values of richness would be found in plantations of up to middle age, considering that in these phases there are environmental characteristics that positively qualify these structures for a greater presence of fauna, such as the shrubby aspect of the plantations and the presence of undergrowth. We performed model selection to observe the effect of environmental variables on mammalian richness. We also performed a multivariate permutational analysis of variance, a non-metric multidimensional scaling and partitioned the beta diversity to observe how the composition was influenced by environmental variables. We found greater richness in the native vegetation compared to eucalyptus plantations. The richness of the plantations varied according to the age, with higher values up to middle age. The composition varied according to the land user/cover, with the eucalyptus age and with the management unit due to the nestedness of species. We suggest that eucalyptus plantations at early ages are more used by mammals due to the shrubby aspect of the stand, generating a positive visual effect for the search of resources and shelter, in addition to the possibility of the occurrence of grasses, some understory and lower anthropogenic disturbance. 相似文献
800.
Abstract Prime mallee lands that once supported high densities of malleefowl, Leipoa ocellata in New South Wales have been extensively cleared for agriculture. Malleefowl are now restricted largely to more and habitat. Given the added competition from introduced herbivores, there is concern that these marginal habitats may not contain sufficient food resources to support viable populations of malleefowl, particularly in times of drought. An opportunistic feeding strategy and omnivorous diet enable malleefowl to exploit a diverse array of food items. Vegetative and invertebrate food resources available to malleefowl in marginal mallee lands were monitored over a period of 1 year during drought. Food resources were varied, transient and patchily distributed. Composition and abundance fluctuated considerably, but potential food was never entirely absent. Despite the prevailing drought, food was obtainable throughout the year provided malleefowl adapted to the fluctuating availability of each of the various potential food resources. Reduced food resources in marginal habitat is not implicated as a major factor in the demise of the malleefowl. Food was most abundant between August and November, inclusive, due largely to the abundance of herbs, the diverse supply of buds, flowers and fruit on perennial shrubs, and the sporadic proliferation of cockroaches. Food availability was least, and therefore most critical, during February, March and June. The most favourable time of the year, in terms of available food resources, for the release of captive-bred individuals was during spring, around September. 相似文献