Climate-related long-term faunal changes in a California rocky intertidal community [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): The effects of gradual climate change (ie, multi-decadal) on biological communities are not well understood for most natural systems, owing principally to the lack of quantitative observations in early studies. ... We resurveyed invertebrate species on an intertidal transect in central California, first established and surveyed in 1931, to assess shifts in community structure.

Quantifying global terrestrial carbon influx and storage as stimulated by an increase in atmospheric carbon dioxide concentration

EXTRACT (SEE PDF FOR FULL ABSTRACT): Measurements of spatial and temporal distributions of carbon dioxide concentration and carbon-13/carbon-12 ratio in the atmosphere suggest a strong biospheric carbon sink in terrestrial ecosystems. Quantifying the sink, however, has become an enormous challenge for Earth system scientists because of great uncertainties associated with biological variation and environmental heterogeneity in the ecosystems. This paper presents an approach that uses two driving parameters to bound terrestrial carbon sequestration associated with an increase in carbon dioxide concentration.

Culture of Moina micrura on various organic waste products

Moina micrura, a cladoceran species, is considered to be one of the best live food organisms for rearing the young larval stages of fish and prawn. Considering the importance of this species in hatchery operations the present study was undertaken to record its fecundity and life span and to culture it using different locally available organic waste products. In indoor culture, a maximum production of 2600 ind/1 and a minimum of 1050 ind/1 were obtained when treated with gram + maize oilcake and "till" oilcake respectively. In outdoor culture, a highest production of 6000 ind/1 was achieved with "Alsi" and "till" oilcakes and a lowest density of 1050 ind/1 with coconut oilcake and raw cattle dung was obtained with an inoculation rate of 5 ind/1.

内蒙古草原中生物土壤结皮生态学研究

1. 生物土壤结皮是干旱半干旱生态系统中的重要组成部分，它可通过增加土壤肥力和稳定性、影响水分再分配和植物萌发、成活、生长和繁殖而对生态系统结构和功能产生重要影响。为阐明生物结皮在内蒙古草地中的作用，本报告对两个草地生态系统进行了为期三年的调查，对生物结皮的氮素输入、对放牧的响应及其与植物的关系进行了综合研究。 2. 利用乙炔还原法，本研究对内蒙古退化草地中的生物土壤结皮中的蓝藻、地衣和地耳的氮素输入进行了为期30个月的连续测定。研究发现：1) 生物结皮固氮活性主要集中于5-10月，呈单峰型曲线，表明生物土壤结皮的固氮作用主要受温度和降雨影响;2) 生物结皮年固氮量为12.99-129.9 kg N•ha-1，98%的氮素固定于6-9月份;3) 按固氮量排序，蓝藻 (61%) > 地衣 (33%) > 地耳 (6%)，表明物种组成和丰度对生物结皮的氮素输入具重要影响。生物结皮的固氮量和季节变化表明生物结皮可以是影响退化草地中植物生长和促进退化草地恢复的重要影响因子。 3. 本研究选择三个放牧处理（长期放牧、短期围封和近期放牧）对生物结皮固氮活性进行了为期3年的研究。结果表明，与短期围封相比，长期放牧造成生物土壤结皮固氮活性下降了99.5%。固氮活性在放牧时间不足11个月时即可下降至最低水平，因此，放牧持续时间短于4个月的轮牧可能有利于生物土壤结皮的固氮。 4. 本研究选择6个放牧梯度（对照：0.00 羊/公顷, 极轻度放牧：1.33羊/公顷，轻度放牧：2.67羊/公顷，中度放牧：4.00羊/公顷，重度放牧：5.33羊/公顷，极重度放牧：6.67羊/公顷)，研究放牧强度对于生物结皮丰度、物种组成和固氮输入的影响。不同放牧强度对生物结皮丰度、物种组成和固氮输入具有重要影响，表明长期放牧可抑制生物土壤结皮在氮素输入和土壤固定方面的作用。极轻度放牧对生物土壤结皮影响不大;轻度放牧造成氮素输入降低了50%;重度和极重度放牧造成氮素输入降低了90%，并可使移动性较强的物种成为生物土壤结皮的优势组分，从而可抑制其土壤固定作用。因此，极轻度和轻度放牧是有利于生物土壤结皮固氮和固定土壤的草地利用方式。 5. 在处于恢复早期的一个退化草地中，我们对生物结皮和植物之间的关系进行了为期2年的研究。结果表明，生物结皮的丰度和物种组成与植物地上生物量和盖度高度相关。生物结皮丰度和氮素输入随植物生物量和盖度下降。结果还表明生物结皮是退化草地的主要氮素输入来源，尤其是在草地恢复初期。植物组织δ15N 低于土壤，这种差异随植物生产力增高而减小，表明生物结皮所固定氮素首先被植物利用，而后返回土壤。生物结皮的固氮输入变化可能是这种变化模式的主要原因，在分解作用和氮素损失中的同位素分馏，以及菌根真菌对于氮素的转运可能也是这种变化模式的原因。结果还显示生物土壤结皮与植物之间可能存在负反馈关系。这种自我调节的反馈过程可能是影响退化草地生态系统生产力和氮素循环的重要调节机制。

Salt-tolerance in mangrove soil bacteria

A total of sixteen bacterial species were isolated from mangrove soils of Karachi, Pakistan. Twelve of the isolates were gram positive while four were gram negative. All sixteen species showed resistance to high concentration of streptomycin, however, resistance to chloramphenicol and tetracycline was variable. The isolates tolerated up to 110‰ salinity and accumulated sodium form the media.

The development of the freezing and export of prawns in India

The paper deals with an overview on the preservation of fish by freezing process. Until a few years ago the surplus catches of fish, prawns were being dried, salted or pickled. The Kerala coast had always yielded large catches of prawns and about 5000 tons of dried prawns were annually exported to Burma and other Eastern countries. The Government of India looking at the great potential of this industry, has now, with a view to encourage exports, provided a series of incentives towards this end.