生物量

Results showed that shoot biomass of H. annuus was significantly higher than that of R. acetosa and R. hastatus; among three plant species, 134Cs specific activity in shoots was the highest in H. annuus after 50 d-treatment, however after 70 d-treatment, that in R. acetosa was the highest. Bioaccumulation ratio reached 1.5, 1.4 and 1.3 in R. acetosa, R. hastatus and H. annuus after 70 d-treatment, and the former two plants kept with trend of continuously increasing. Three plants were resistant to 134Cs contaminated soil and capable of translocating 134Cs from soil to plants. Among them, H. annuus removed greatest 134Cs amount in the aboveground part during the experiment period, and R. acetosa, R.

结果表明，向日葵地上部生物量显著高于酸模和戟叶酸模；处理50d时，向日葵地上部134Cs比活度在3种植物中达到最高，而在处理70d时，酸模地上部134Cs的比活度达到最高；处理70d时，酸模、戟叶酸模和向日葵对134Cs的富集系数均大于1，分别达到1.5、1.4和1.3，且前2种植物继续保持快速上升的趋势。3种植物对铯污染土壤具有一定的忍耐性，并具有较强的从土壤向植物转移铯的能力；在本实验期内（70d）向日葵对土壤中放射性铯的剔除能力最强，而酸模和戟叶酸模则具有更强的铯转移能力。

However, the variations in annual precipitation and mean temperatures could not explain the highest ABD in the alpine fir forest in Sergyemla Mountains because ABD distribution patterns of natural vegetation can be limited by additional climatic factors such as solar radiation, wind, moisture and related water/energy balances.

我们认为，自然植被地上部分生物量的分布格局受到更为复杂的气候因子的制约，例如太阳辐射、湿度、风、水分和能量平衡等。

However remarkable impacts were observed in the plantation in terms of community physiognomy,community structure,species composition,species richness,and biomass accumulation.1 Planting trees made community structure simple.Betula alnoidis plantation had three layers including a dominant arbor layer,a complex and well developed shrub layer and a poorly developed vine layer.The arbor layer contained few species and had a single layer.The mountain rain forest had 4 layers including the dominant arbor layer,shrub layer,grass layer and vine layer.The vine layer was well developed and very rich in species composition,and the arbor layer contained as many as 38 species that could be grouped into 3 layers.2 Sequenced by the important value,main species for the plantation and the nature forest were totally different,and the plantation had one dominant species while the nature forest contained many dominant species.3 Planting trees changed the community physiognomy.

但是人工种植西南桦林对群落的季相外貌、群落的结构、物种组成、物种丰富度以及生物量等方面有较大的影响。1人工造林使得群落结构简化，西南桦人工林的层次结构有3层，以乔木层占优势，并且有种类多而发达的灌木层，同时，藤本植物欠发达，但是乔木层树种单一，明显仅有一层；山地雨林的层次结构有4层，以乔木层占优势，还有灌木层、草本层和藤本植物，藤本植物种类多，十分发达；乔木层树种丰富，可达38种，乔木层还可分为3层。2人工造林较大程度地改变了群落的物种组成，根据重要值的大小排列，人工林和天然林的主要物种组成已经完全不同；并且人工林单优树种明显，而天然林就含有较多的优势树种。3人工造林改变了群落的外貌。

The result of these varieties is to accelerate photosynthesis and improve seedlings bio-mass accumulation.There exists some remarkable plus correlative relation between Machurian Ash seedling leaf net photosynthetic rate under light saturated condition and leaf nitrogen content.

水曲柳幼苗叶片的光饱和净光合速率与叶片氮含量之间也存在着强烈的正相关关系，适当提高氮素养分的供应会相应增加叶片中的氮含量，从而促进植物光合作用，有利于生物量的积累。

Although AM fungi and other soil microorganisms had no significant effect on above ground biomass in ryegrass and bahia grass,both AM fungi and other soil microorganisms decreased the uptake of~(89)Sr in the two grass species,though to a more or less extant.

尽管内生菌根菌和其他土壤微生物对黑麦草和百喜草的地上部分生物量没有明显影响，但它们都不同程度地降低了两种草对89Sr的吸收。

Key words: ^89Sr; ryegrass; bahia grass; soil microorganisms; AM fungus

尽管内生菌根菌和其他土壤微生物对黑麦草和百喜草的地上部分生物量没有明显影响，但它们都不同程度地降低了两种草对^89Sr的吸收。

In the lower region , the elevation of beach was higher, the plant density and biomass increased and the habitat space was enlarged, so the species and individuals numbers of benthos were both more than the uppers.

从低潮区、中潮区再到高潮区，植株高度及地上部分生物量逐渐增大，初级生产力的不断提高，沉积环境的稳定性加强，底栖动物多样性及物种丰度也相应增大。

The optimum combination of carbon source and nitrogen source was 3 % corn meal, 1.5 % glucose, 2 % bean flour and 0.2 % peptone, with the biomass of 1.781 g/100 ml.

最佳碳、氮源组合为玉米粉3.0%，葡萄糖1.5%，黄豆粉2.0%，蛋白胨0.2%，生物量为1.781g/100ml。

Clipping led to increased aboveground biomass and over-compensation in the absence of fertilization, but the degree of compensation depended on intensity, frequency and time of clipping.

不施肥，刈割可促进冷地早熟禾地上生物量的增加并发生超补偿，但补偿程度因刈割强度、刈割频度和刈割时间而异；施肥时，刈割没有或很少促进植株发生超补偿。

The study was conducted at the Poplar Forest Farm of Guan County, Shandong Province.

本项研究主要在山东省冠县毛白杨林场进行，研究了毛白杨片林的林分生长规律、生物量积累及它们与土壤条件的关系。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。