山东省的菌根真菌及分布

1842年Vittadini观察到树木小根可以从在其上面形成根套的真菌中获得营养。1885年Frank发展和完善了Vittadini 的观察,提出     

“引黄济青”输水沿线水生生物分布与蓄水库富营养化关系的研究

“引黄济青”是国家“七五”重点工程,由黄河下游博兴县境内打渔张闸引水,在渠首沉沙后,再经惠民、东营、潍坊和青岛的10个县区约253km的明渠输送,到达唠山县棘洪滩蓄水库蓄存,实现向青岛市日供水3.0×10~5m~3。明渠输水过程中,来白沿线的营养物质会污染水体,加之输水在库中滞留时间长,会不会发生富营养化,这是社会普遍关注的问题。     

Small-scale environmental heterogeneity and the analysis of species distributions along gradients

Abstract. The observed distribution of a species along an environmental gradient is strongly affected by environmental variability within a quadrat. Because a quadrat does not represent a point along an environmental gradient, but rather a range of conditions, it is likely to contain species not typically associated with the mean conditions in the quadrat. Systematic relationships exist between a species' true distribution, the observed distribution as a function of mean quadrat environment, and the frequency distribution of the environment within that quadrat. The observed species habitat breadth increases and the observed maximum abundance decreases as within-quadrat environmental heterogeneity increases. If species distributions or beta diversities are to be compared among species or coenoclines, they should be correctedforintra-quadratheterogeneity.Wederive simple corrections for environmental heterogeneity. The distributions of hardwood forest understory species along a soil acidity gradient in the North Carolina piedmont are presented as an example.     

Changes in the Subcellular Distribution of Free Amino Acids in Relation to Light Conditions in Cells of Chara corallina

Subcellular concentrations of free amino acids in internodal cells of a Characeae, Chara corallina, were measured in the dark and in the light. Using an intracellular perfusion technique, we measured concentrations of amino acids in the vacuole, in the flowing sol endoplasm and in the cortical gel layer. The sol endoplasm was predominantly the cytosol. On the basis of microscopic observations, the gel layer appeared to be occupied predominantly by a layer of chloroplasts, while the sol endoplasm was free from chloroplasts. Both in the light and in darkness, the major amino acids in the internodal cells were isoasparagine, glutamic acid, aspartic acid, serine, glycine and alanine, as reported by Sakano and Tazawa (1984). The same major amino acids are found in each of the three compartments. The pattern of distribution of amino acids in the vacuole was similar to that in the sol endoplasm, but quite different from that in the gel layer. The total level of amino acids in the light was lower than that in darkness. The amino acid composition did not change very much, but the subcellular distribution of amino acids differed significantly between cells subjected to illumination and those kept in the dark. Concentrations of amino acids in both the vacuole and the gel layer decreased, whereas those in the sol endoplasm were almost constant.     

Phytoecological importance,mutual redundancy and phytological threshold values of certain climatic factors

A combination of methods (intensity of indication, floristic and mesological redundancy analysis, beta-diversity analysis, principal components analysis and Wildi's interactive ranking procedure) were used to evaluate redundancy and relative phytoecological importance among 80 climatic variables in Galicia (N.W. Spain). The information they contained was found to be adequately summarized by just 3 factors thought to play a major role in regulating the distribution of the species considered in the study area and similar areas: Baudiere's QE index, mean minimum temperature in the coldest month and mean temperature range in the coldest month. For these three factors, phytoclimatic thresholds were determined by examining beta-diversity and were used to define phytoclimatic zone types.

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Resumen Se valora la redundancia e importancia fitoecológica relative de 80 variables climáticas en Galicia (N.O. de España) empleando una combinacion de diferentes metodos (intensidad indicadora, análisis de la redundancia florística y mesológica, análisis de beta-diversidad, análisis de componentes principales y el método de ordenación interactiva de Wildi). La información contenida en esta variables es adecuadamente resumida por 3 factores que juegan un papel predominante en regular la distribución de las especies consideradas en el area de estudio y areas similares: el índice QE de Baudiere, la temperatura media de las mínimas del mes más frío y la oscilación térmica del mes más frío. Para estos factores el análisis de la beta-diversidad permitió determinar los umbrales fitoclimáticos utilizados en la definición y cartografía de las zonas fitoclimáticas.

     

Population dynamics of Gyrodactylus sp. (Monogenea) infecting the sand goby in the Oslo Fjord, Norway

Prevalence and abundance of Gyrodactylus sp. on the 1993 year-class of sand gobies Pomatoschistus minutus in the Oslo Fjord, Norway, decreased slightly during the cold months, increased as temperature increased in spring, reaching a peak in June, then decreased significantly, corresponding with a decline in the number of hosts from August. Abundance and, especially, prevalence increased again in September, and decreased in late autumn. Death of the most heavily infected hosts, and/or host resistance might be responsible for the decline in parasite numbers on post-spawners in summer. The young of the year (1994 year-class) were probably infected shortly after they commenced benthic life in July, and prevalence and abundance increased significantly throughout late summer and autumn. Parasite abundance on males was significantly higher than on females at the height of the breeding season in June, but significantly lower at the end of the breeding season in July. Two-thirds of the parasites infected the gills, oral cavity and pharynx. The proportion of parasites on the body, head and fins increased on both sexes, but significantly more so on males, during the breeding season of the host, when parasite intensity was highest. Possible routes of transmission of the parasite are discussed.     

Spatial and temporal distributions of salmonids in two ponds in Newfoundland, Canada

Spatial and temporal distributions of salmonids were examined in Junction Pond, Northeast River, Placentia and Conne Pond, Conne River, Newfoundland using Lundgren multiple-mesh experimental gillnets. Both ponds contain populations of Atlantic salmon and brook trout with Junction Pond also possessing brown trout and resident Arctic charr. For salmon parr there was a significant month effect in distribution of catch rates in both ponds, and in Junction Pond, there was a significant diel effect. There was also significant variation in catch rates by lentic zone. For brook trout, there was a significant lentic zone × month interaction in Junction Pond; in Conne Pond, the main effects lentic zone and month were significant. Highest benthic catch rates of Atlantic salmon parr occurred in the littoral zone of both ponds. Most captures of brook trout also occurred benthically in both ponds; similar to salmon parr, littoral zone catch rates were higher than those of the deeper benthic area in Conne Pond but the reverse was true for Junction Pond. For both salmon parr and brook trout, the deeper benthic area and the pelagic area were relatively important rearing habitats in each pond. The distribution of catches for brown trout (few in number relative to the other species) in Junction Pond was similar to that of brook trout while Arctic charr were found mainly pelagically. Within the benthic area, most Arctic charr were caught at depths beyond the littoral zone. There was a tendency for Altantic salmon parr and brook trout found in the deeper benthic area and the pelagic area to be significantly larger and older than those in littoral zone in each pond. Sizes of Arctic charr did not differ significantly among lentic zones.     

Significant extension in northern Australia of the known geographic range of the Shield Shrimp Triops australiensis (Crustacea: Notostraca)

The program BIOCLIM predicts the total geographic distribution of species, based upon the biogeoclimatic characteristics common to the localities at which they are known to occur. Field studies in the Northern Territory have located the Shield Shrimp Triops australiensis at localities substantially north of its known and predicted geographic distribution.     

Macrophytes and flood plain water dynamics in the River Danube ecotone research region (Austria)

In the ecotone research region of the Danube in Austria (Man-and-the-Biosphere (MaB)- project 5/21, Austrian Academy of Science) the macrophytes are one of the most important groups of organisms investigated. The species composition and the plant mass in hydrologically dynamic, and in predominantly stagnant sections of a system of lateral branches and sloughs were studied. This study showed that areas protected from frequent disturbance by floods had a greater number of species and higher biomass of aquatic macrophytes. Some species were shown to be evenly distributed throughout the branch system, whereas other species tended to form rare, but large singular patches. A set of new data elaboration techniques enabled us to describe the distribution pattern of the aquatic vegetation in this large branch system of the River Danube.