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91.
92.
J. Baird Callicott 《Journal of biosciences》2002,27(4):409-420
Classic ecological restoration seems tacitly to have taken the Clementsian “balance of nature” paradigm for granted: plant
succession terminates in a climax community which remains at equilibrium until exogenously disturbed after which the process
of succession is restarted until the climax is reached. Human disturbance is regarded as unnatural and to have commenced in
the Western Hemisphere at the time of European incursion. Classic ecological restoration thus has a clear and unambiguous
target and may be conceived as aiming to foreshorten the natural processes that would eventually lead to the climax of a given
site, which may be determined by its state at “settlement”. According to the new “flux of nature” paradigm in ecology a given
site has notelos and is constantly changing. Human disturbance is ubiquitous and long-standing, and at certain spatial and temporal scales
is “incorporated”. Any moment in the past 10,000 years that may be selected as a benchmark for restoration efforts thus appears
to be arbitrary. Two prominent conservationists have therefore suggested that the ecological conditions in North America at
the Pleistocene—Holocene boundary, prior to the anthropogenic extinction of the Pleistocene megafauna, be the target for ecological
restoration. That suggestion explicitly assumes evolutionary temporal scales and continental spatial scales as the appropriate
frame of reference for ecological restoration. However, ecological restoration should be framed in ecological spatio-temporal
scales, which may be defined temporally in reference to ecological processes such as disturbance regimes and spatially in
reference to ecological units such as landscapes, ecosystems, and biological provinces. Ecological spatio-temporal scales
are also useful in achieving a scientifically defensible distinction between native and exotic species, which plays so central
a role in the practice of ecological restoration and the conservation of biodiversity. Because post-settlement human disturbances
have exceeded the limits of such scales, settlement conditions can be justified scientifically as appropriate targets of restoration
efforts without recourse to obsolete teleological concepts of equilibria and without ignoring the presence and ecological
influence of indigenous peoples. 相似文献
93.
I. V. Epur 《Russian Journal of Marine Biology》2002,28(6):411-414
The results of 6-year-long observations on the size of some fish species of the Far East State Marine Reserve (Peter the Great Bay, Sea of Japan) suggest that resident fishes attain maximum size in the waters of the reserve. Compared to previously known sizes of fish, record values were found for the white-spotted greenling Hexagrammos stelleri (540 mm), the frog sculpin Myoxocephalus stelleri (490 mm), the snowy sculpin M. brandti (418 mm); the fringed blenny Chirolophis japonicus (520 mm), and some other fishes. These data confirm the opinion that the Marine Reserve waters are the reservation of the genofond of the inhabiting fish. 相似文献
94.
Marc Pollet 《Journal of Insect Conservation》2001,5(2):99-116
The conservation value of grassland and reed marsh habitats in Belgium was determined on the basis of dolichopodid communities (Diptera: Dolichopodidae). Four grassland and one reed marsh sites within the 'Bourgoyen-Ossemeersen' Nature Reserve (B.O.) (Ghent) were sampled with white water traps from March 1993 until March 1994. Subsequently, these soil faunas were compared with those of reed marsh habitats in 'Het Meetjeslandse Krekengebied' (M.K.) sampled in 1990. Comparisons of species communities were carried out by means of multivariate analysis techniques. The DCA and CCA on the B.O. sites produced a clear separation between the grassland and the reed marsh communities. Light intensity and soil humidity were among the most important factors determining species distributions. The comparison between the B.O. and M.K. communities revealed that sampling sites were clustered according to their geographical location rather than to habitat type. Overall species richness and diversity was not significantly different between grasslands and reed marshes. However, conservation quality estimates of the sites using the Site Conservation Quality Index (SCQI) indicated that reed marshes comprise a considerably larger number of rare and Red Data Book species. Moreover, besides typical reed marsh-inhabiting species, reed marshes also house species with other ecological affinities sometimes in rather high abundance. As a result, reed marshes are considered highly valuable for the survival of several wetland dolichopodid species. 相似文献
95.
The Abe Bailey Nature Reserve, South Africa has been identified as a potential community resource reserve compatible with biodiversity conservation. As part of the planning and public participation phase this study investigated the potential for sustainably harvesting medicinal plants. Medicinal plant use data on local species, parts used and harvesting techniques, in collaboration with neighbouring traditional healers were collected. A census of these plants was conducted in the reserve and frequency, density and abundance were calculated. A medicinal plant rating system for assessing conservation priorities was used to combine both social-qualitative and ecological-quantitative data. Five medicinal species suitable for high impact harvesting were identified. Thirty-four species have potential to be set up as harvesting trials to determine sustainable quotas. Thirty-one medicinal species including Boophane disticha, Dicoma anomala, Eucomis autumnalis, Hypoxis hemerocallidea, Pentanisia prunelloides and Indigofera daleoides are considered to be site-specific sensitive species and should not be harvested from the reserve. Following this research an on site nursery has been started at the reserve. A multi-pronged approach involving harvesting trials, propagation and plant rescue from developments to cope with escalating demand and dwindling natural populations needs to be implemented. 相似文献
96.
There is a growing body of evidence that suggests the effective functioning of marine reserves is dependent on the dispersal
and recruitment of larvae. Enhanced production inside reserves is predicted to lead to a net larval export and increased settlement
and recruitment outside reserve boundaries. However, larval retention in bays is also well documented. Since bays are increasingly
being used as reserve areas, planktonic larvae of benthic marine invertebrates were sampled from two semi-enclosed marine
reserves during flood and ebb tides to determine whether these bays are acting as net exporters of larvae. Neither reserve
was a net importer or exporter of species richness, larval abundance or diversity, although one reserve showed a small export
of species richness during the hours of darkness. Both reserves balanced the net import of some species with a net export
of others, which was generally related to adult or larval abundance, although exceptions were found in one reserve. Significant
effects of light were found, with the net import or export of some species occurring exclusively during either the hours of
daylight or darkness. An increased understanding of larval sink-source dynamics in bays is essential for ensuring their effective
use as marine reserves to meet specific conservation needs.
Guest editors: J. Davenport, G. Burnell, T. Cross, M. Emmerson, R. McAllen, R. Ramsay & E. Rogan
Challenges to Marine Ecosystems 相似文献
97.
E. Alliot M. Djabali A. Pastoureaud H. Thebault 《Biochemical Systematics and Ecology》1984,12(2):209-213
The effects of starvation on sea bass (Dicentrarchus labrax) fingerlings (initial average weight 9.5 g) at 19° in sea water were studied. Fish start to die on day 19. Proximate analysis shows that water content increases with starvation time whereas protein and lipid contents decrease. After an initial decline, nitrogen excretion remains stable from day 2 to day 14. Starvation resulted in a reduction of liver, muscle and digestive tract lipids, mainly the triglycerides which are significantly reduced within the first week of starvation. The influence of water temperature on these changes is discussed. 相似文献
98.
The range of uses of a conservation area by a nearby population was quantified by questionnaires applied to residents of Santa Helena county, Brazil. Of the 312 responses compiled, 71.2% of the residents acknowledged the presence of a conservation unit within the county limits while only 59.3% of the respondents had participated in some recreational or leisure outdoor activity within the unit. Activities cited by respondents included games (11.7%), beach visits (11.4%), cross-country walks (9.4%), and fishing (8.3%). A possible visitor fee to improve infrastructure within the area was approved by 64.9% of the interviewees. Suggested visitor fee varied from 50 cents to two dollars. 相似文献
99.
《Current biology : CB》2020,30(7):1280-1286.e2
100.
The phosphorus (P) fractions and bioavailable P in the sediments from the Quanzhou Bay Estuarine Wetland Nature Reserve were investigated using chemical extraction methods for the first time to study the distribution and bioavailability of P in the reserve sediments. A hypothesis was presented suggesting that the bioavailable P in the sediments could be evaluated using the P fractions. The total phosphorus (TP), inorganic phosphorus (IP), organic phosphorus (OP), non-apatite phosphorus (NAIP), and apatite phosphorus (AP) contents in the sediments were in the ranges of 303.87–761.59 mg kg−1, 201.22–577.66 mg kg−1, 75.83–179.16 mg kg−1, 28.86–277.90 mg kg−1, and 127.36–289.94 mg kg−1, respectively. The water soluble phosphorus (WSP), readily desorbable phosphorus (RDP), algal available phosphorus (AAP), and NaHCO3 extractable phosphorus (Olsen-P) contents in the sediments were in the ranges of 0.58–357.17 mg kg−1, 80.77–586.75 mg kg−1, 1.09–24.12 mg kg−1, and 54.96–676.82 mg kg−1, respectively. The correlation analysis results showed that the NAIP was the major component of the bioavailable P and that the impact of the AP on the bioavailable phosphorus may be minimal. Due to the low TP content in the sediments of the Quanzhou Bay Estuarine Wetland Nature Reserve, the potential pollution risks of P in the sediments may not be very high. The results also show that the bioavailable P concentrations in the sediments of the Quanzhou Bay Estuarine Wetland Nature Reserve could not be evaluated by measuring the P fractions and that the hypothesis was untenable. 相似文献