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1.
Synopsis Atlantic croaker, Micropogonias undulatus, sampled from a transect along a pollution gradient show a trend of declining growth and physical condition. This trend is apparent in the mean size of 0-group croaker, in their recent growth rate measured by marginal otolith increment widths, in longer term growth rate as indicated by relative otolith weights, and in general physical condition as measured by an index of condition of the caudal fin. We suggest that these measures are indicators of stress associated with environmental conditions. Because croaker from different positions along the pollution gradient were distinguishable, it appears that they remain for extended periods within areas of degraded environmental quality. 相似文献
2.
Distinct effects of climate warming on populations of silver fir (Abies alba) across Europe 下载免费PDF全文
3.
The influence of metabolic rate on otolith increment width in Atlantic salmon parr, Salmo salar L. 总被引:1,自引:0,他引:1
P. J. Wright 《Journal of fish biology》1991,38(6):929-933
The influence of metabolic rate on otolith accretion in Atlantic salmon parr was investigated by comparing oxygen consumption rate and increment width in fast and slow growing individuals. Increment width was found to be positively correlated to mean daily oxygen consumption in both fast growing (S1) and slow growing (S2) parr. The results support previous suggestions that a process related to metabolic rate, rather than somatic growth, governs the rate of otolith accretion. 相似文献
4.
We evaluated the spatial and temporal scales over which otolith signatures varied in a reef fish on the Great Barrier Reef
(GBR) using the non-dispersing damselfish Acanthochromis polyacanthus. We found a robust multi-element separation in otolith signatures from reef clusters in the northern and southern GBR. Variance
components indicated that this spatial scale accounted for the majority of the variation in two elemental ratios (Ba/Ca and
Sr/Ca) over the 2 years of the study. There was also significant variation in elemental signatures between otoliths collected
over two consecutive years, as well as within a season. Individual reefs within clusters were less distinguishable based on
otolith chemistry and were probably observed by differences within reefs (among sites and broods within sites). These results
indicate that it may be difficult to determine the reef of origin for individual fish using otolith chemistry, while determining
natal region seems a realistic goal. 相似文献
5.
采用“盐分增量法”测定了松嫩平原大安古河道试验站典型的羊草.星星草.碱地蒲公英群落分布区的植被蒸散量。结果表明,盐分增量法是一种测定植被蒸散量的新方法,可有效地测定植被蒸散量;植被日均蒸发量随植被盖度增加不断减少,日均蒸腾量随植被盖度增加逐渐增大,由于蒸腾量增加幅度大于同期蒸发量减少幅度,植被日均蒸散量随植被盖度增加而增大。 相似文献
6.
青海湖裸鲤生长特征的研究 总被引:13,自引:1,他引:12
对2002年5月—2003年7月采自青海湖的1174尾青海湖裸鲤样本年龄进行了耳石鉴定,并依据年龄推算了生长率。青海湖裸鲤体长与体重的关系为:W=0.000174×L2.4990(♀)、W=0.0000402×L2.7538(♂),雌、雄个体生长差异显著。其体长Von Bertalanffy生长方程为:Lt=551.9301(1-e-0.0711(t 0.3044))(♀),Lt=682.8688(1-e-0.0530(t 0.4240))(♂);体重Von Bertalanffy生长方程为:Wt=1237.3431(1-e-0.0711(t 0.3044))2.4990(♀),Wt=2567.3242×(1-e-0.0530(t 0.4240))2.7538(♂)。其雌、雄生长拐点分别为12.57龄和18.67龄。 相似文献
7.
To estimate the age and growth of dominant lanternfishes in the Kuroshio–Oyashio Transition Zone, we examined the sagittal
otolith microstructure of Symbolophorus californiensis (n = 30) and Ceratoscopelus warmingii (n = 93) collected from the western North Pacific during 1997–2003. Age of S. californiensis ranged from 81 to 541 days corresponding to postmetamorphosis stage (juveniles and adults), and the von Bertalanffy model
was fitted: L
t
= 128[1 − exp{−0.003(t − 1.52)}], where L is the standard length (mm) and t is age in days. Age of C. warmingii ranged from 6 to 416 days, and growth before metamorphosis was linear (L
t
= 0.346t + 1.51), and the von Bertalanffy model was fitted to the postmetamorphosis stage: L
t
= 80.8 [1 − exp{−0.00769(t − 34.4)}]. Growth of these two lanternfishes was faster than that of other lanternfishes in previous studies but considerably
slower than that of Japanese sardine (Sardinops melanostictus) and anchovy (Engraulis japonicus) distributed in the Kuroshio–Oyashio Transition Zone. Temperature and prey availability are discussed in relation to this
difference in growth rate. 相似文献
8.
R. Niloshini Sinnatamby Milton Shears J. Brian Dempson Michael Power 《Journal of thermal biology》2013
Predicted increases in temperature associated with climate change are expected to have consequences for fish, in particular for Arctic charr, Salvelinus alpinus, a cold-adapted fish species. Despite differences in predicted hydroecological responses to climate change in fluvial and lacustrine environments, little is known of whether fluvial and lacustrine Arctic charr populations may respond differently to increasing temperatures. In order to compare growth and thermal habitat use between habitat types, otolith-inferred average water temperatures estimated from whole otoliths and fork lengths at capture were measured for young-of-the-year (YOY) Arctic charr obtained from two proximal fluvial and lacustrine sites in Labrador, Canada. Otolith-inferred average experienced water temperatures were not significantly correlated with air temperatures at both sites, suggestive of behavioural thermoregulation by YOY. The majority of Kogluktokoluk Brook (fluvial) YOY were found using water temperatures consistent with laboratory determined preferred temperatures for juvenile Arctic charr, whereas most Tom's Pond (lacustrine) YOY were found using temperatures ranging between preferred temperatures and optimal temperatures for growth. There was no consistent difference between mean water temperatures used between YOY from the two sites. Otolith-inferred average experienced water temperatures were only correlated to fork lengths in Tom's Pond YOY. The lack of correlation in Kogluktokoluk Brook YOY is argued to reflect resource partitioning occurring as a result of territoriality known to occur among stream salmonids. The limited range of temperatures used by fluvial YOY in this study, particularly the lack of cooler temperatures, also suggests that fluvial YOY may face barriers to thermal refugia, and as a result may be particularly vulnerable to climate change. 相似文献
9.
Logan T. Berner Pieter S. A. Beck Andrew G. Bunn Scott J. Goetz 《Global Change Biology》2013,19(11):3449-3462
Russia's boreal (taiga) biome will likely contract sharply and shift northward in response to 21st century climatic change, yet few studies have examined plant response to climatic variability along the northern margin. We quantified climate dynamics, trends in plant growth, and growth–climate relationships across the tundra shrublands and Cajander larch (Larix cajanderi Mayr.) woodlands of the Kolyma river basin (657 000 km2) in northeastern Siberia using satellite‐derived normalized difference vegetation indices (NDVI), tree ring‐width measurements, and climate data. Mean summer temperatures (Ts) increased 1.0 °C from 1938 to 2009, though there was no trend (P > 0.05) in growing year precipitation or climate moisture index (CMIgy). Mean summer NDVI (NDVIs) increased significantly from 1982 to 2010 across 20% of the watershed, primarily in cold, shrub‐dominated areas. NDVIs positively correlated (P < 0.05) with Ts across 56% of the watershed (r = 0.52 ± 0.09, mean ± SD), principally in cold areas, and with CMIgy across 9% of the watershed (r = 0.45 ± 0.06), largely in warm areas. Larch ring‐width measurements from nine sites revealed that year‐to‐year (i.e., high‐frequency) variation in growth positively correlated (P < 0.05) with June temperature (r = 0.40) and prior summer CMI (r = 0.40) from 1938 to 2007. An unexplained multi‐decadal (i.e., low‐frequency) decline in annual basal area increment (BAI) occurred following the mid‐20th century, but over the NDVI record there was no trend in mean BAI (P > 0.05), which significantly correlated with NDVIs (r = 0.44, P < 0.05, 1982–2007). Both satellite and tree‐ring analyses indicated that plant growth was constrained by both low temperatures and limited moisture availability and, furthermore, that warming enhanced growth. Impacts of future climatic change on forests near treeline in Arctic Russia will likely be influenced by shifts in both temperature and moisture, which implies that projections of future forest distribution and productivity in this area should take into account the interactions of energy and moisture limitations. 相似文献
10.
Sybryn L. Maes Michael P. Perring Margot Vanhellemont Leen Depauw Jan Van den Bulcke Guntis Brmelis Jrg Brunet Guillaume Decocq Jan den Ouden Werner Hrdtle Radim Hdl Thilo Heinken Steffi Heinrichs Bogdan Jaroszewicz Martin Kopecký Frantiek Mli Monika Wulf Kris Verheyen 《Global Change Biology》2019,25(1):201-217
Forecasting the growth of tree species to future environmental changes requires a better understanding of its determinants. Tree growth is known to respond to global‐change drivers such as climate change or atmospheric deposition, as well as to local land‐use drivers such as forest management. Yet, large geographical scale studies examining interactive growth responses to multiple global‐change drivers are relatively scarce and rarely consider management effects. Here, we assessed the interactive effects of three global‐change drivers (temperature, precipitation and nitrogen deposition) on individual tree growth of three study species (Quercus robur/petraea, Fagus sylvatica and Fraxinus excelsior). We sampled trees along spatial environmental gradients across Europe and accounted for the effects of management for Quercus. We collected increment cores from 267 trees distributed over 151 plots in 19 forest regions and characterized their neighbouring environment to take into account potentially confounding factors such as tree size, competition, soil conditions and elevation. We demonstrate that growth responds interactively to global‐change drivers, with species‐specific sensitivities to the combined factors. Simultaneously high levels of precipitation and deposition benefited Fraxinus, but negatively affected Quercus’ growth, highlighting species‐specific interactive tree growth responses to combined drivers. For Fagus, a stronger growth response to higher temperatures was found when precipitation was also higher, illustrating the potential negative effects of drought stress under warming for this species. Furthermore, we show that past forest management can modulate the effects of changing temperatures on Quercus’ growth; individuals in plots with a coppicing history showed stronger growth responses to higher temperatures. Overall, our findings highlight how tree growth can be interactively determined by global‐change drivers, and how these growth responses might be modulated by past forest management. By showing future growth changes for scenarios of environmental change, we stress the importance of considering multiple drivers, including past management and their interactions, when predicting tree growth. 相似文献