内蒙古温带草原生态系统过程对气候变化响应的实验研究

羊草草原、大针茅草原和草甸草原是内蒙古温带典型草原地区的三种主要植被类型，本文以此为研究对象，应用时空替代、温室、网室、自然降水接移、养分添加等多种方法模拟未来可能发生的气候变化，研究了这些变化对上述草原植物群落和生态系统过程的直接和间接影响。主要研究结果如下： 1. 气候变暖及其诱导的土壤养分释放速率增加对植物群落有明显的影响，表现在种种植物群落在高度、盖度、密度和生物量等都有不同程度的变化。说明我国温带草原生态系统对气候变化反应敏感。 2. 在群落说平上，气候变暖直接或间接使地上生物量提高17%～90%，但在种群水平，不同种群对模拟气候变化的响应具有很强的个性，而不具普遍性，不同种群反应的大小、方向不同。因此由在不同群落进行研究得出的推论只有部分是可能的，并且即使观测到相类似的反应，它们内在的机制也很可能是不同的。 3. 气候变化显著地影响着凋落物的分解特征。但不同的气候变化情景下，凋落物分解过程的响应不同。在温度升高降水变化不大或升高的情景下，凋落物的分解速率将加快;在气温上升，降水明显下降的情景下，凋落物的分解速率将降低。 4. 草甸草原土壤碳素释放过程和氮素矿化过程对气候变暖有明显的响应。气候变暖将促进土壤有机碳的释放，使草甸草原土壤成为碳源，同时加速氮素矿化速率，在一定程度上提高土壤有效养分的浓度。 5. 在中小尺度上，海拔样带所是应用时空替代原理，研究陆地生态系统与气候变化的理想平台，生物量是综合反应气候变化对土壤-植物系统影响的敏感指标。 6. 草原土壤有机碳和氮在2m～3m的小尺度上存在空间自相关性，其空间自相关尺度受人类活动的影响。

Daily rainfall along the United States Pacific Coast appears to conform to a square-root normal probability distribution

EXTRACT (SEE PDF FOR FULL ABSTRACT): As part of a study of climatic influences on landslide initiation, a statistical analysis of long-term (>40 years) records of daily rainfall from 24 Pacific coastal stations, from San Diego to Cape Flattery, disclosed an unexpected result - the square root of the daily rainfall closely approximates a normal distribution function. ... This paper illustrates the use of the square-root-normal distribution to analyze variations in precipitation along the mainland United States Pacific Coast with examples of orographic enhancement, rain shadows, and increase in precipitation frequency with geographic latitude.

A preliminary study on the fishery resources of the mangrove swamps of Sundarbans, West Bengal

West Bengal holds an important position in fisheries development as the state has all types of captive, culture freshwater and brackish water fisheries. A survey of forest areas of Sundarbans indicates the total annual catch to be 2500 metric tonnes. On average 4,000 persons are engaged in daily fishing with 1.5 kilogrammes of fish catch per fisherman per day and during the 6 months from September to February on an average 6,000 persons are engaged in fishing. About 70% of total catch of fish is collected during this period. Statistical analysis of the data collected for the study has clearly indicated that a rational and scientific exploitation of fish species inhabiting the rivers and creeks of Sundarbans estuary has immense economic potentialities.