Sediment transport from continuous monitoring in a perennial Mediterranean stream

Sediment transport in the Ribera Salada stream was estimated from continuous suspended and bedload monitoring between 2005 and 2008. The Ribera Salada basin is a mountainous perennial river in the Southern Pyrenees and is representative of the extensive forestry land use in this upland region. Water and sediment fluxes have been analysed with the aim of determining the thresholds, duration, ranges and relative contributions of the two sediment transport modes (suspended and bedload), and their variability in relation to the basin's annual hydrology. The stream's hydrology in the first two sampling years was average in the context of a 10-yr series of the basin, while 2007–2008 can be classified as a wet year. The specific total sediment load during the study period amounted to 12 t km⁻²y⁻¹, a low value compared with similar Mediterranean counterparts. The maximum load (31.5 t km⁻²y⁻¹) was observed during the wettest year of the monitoring programme. During average years most of the total load (> 90%) was transported in suspension; consequently, suspended sediment transport is more frequent through time. In contrast, bedload occurs sporadically during floods that exceed certain hydraulic thresholds, corresponding to a flow equalled or exceeded 4% of the time, that yields an average shear stress of ∼ 35 N m⁻². Under such conditions bedload transport becomes relevant and, if the threshold is frequently exceeded as in relatively wet years such as 2007–2008, may constitute the majority of the total sediment load (74%). This paper provides new evidence of the distinct role of sediment transport modes in stable fluvial environments where only sporadic inputs of surplus energy (flow discharge) determine the dominant mode, magnitude and duration of their respective contribution.     

新型甜菜夜蛾诱捕器的设计与田间试验效果分析

根据甜菜夜蛾成虫飞行的生物学行为，设计出了一种结构合理、使用方便的实用新型诱捕器。在田间进行诱蛾试验，结果表明，该种诱捕器诱虫效果（平均总诱蛾量为171．5头）高于常用的水盆诱捕器（平均总诱蛾量为108．5头）和美国的Unitrap诱捕器（平均总诱蛾量为140头）。在使用过程中，操作简单、在能保证诱芯的充分散发的同时，能避免阳光直射和雨水直接冲刷诱芯。该种诱捕器几乎不受田间环境的限制，可常年使用。     

蜘蛛的几种定量采集方法

介绍了野外采集森林冠层、树干和地表层蜘蛛的冠层喷雾法、树干陷阱法和单位地表面积法,分别阐述了每种方法的特点及使用时的注意事项,并探讨了3种采集方法在生物多样性研究及保护中的应用前景。     

Integrated rodent management in outbreak-prone upland rice growing areas of Northern Laos

An integrated rodent management program was tested in outbreak-prone areas in three provinces of the Northern uplands of Laos (Luangprabang, Phongsaly, Houaphanh). In each province, it was replicated in six villages and associated upland rice fields; six neighboring villages served as negative controls. The program started end of 2010 and aimed at protecting the wet season rice harvest of 2011 against rodent damage. Rodent control techniques included sustained trapping, rodent-proofing of grain stores, rodent hunts and village sanitation campaigns, and biological rodent control using the protozoan parasite Sarcocystis singaporensis. The measures were embedded in a community approach, which was coordinated by provincial and district agricultural officers. Compared to the control villages, which showed on average 10.9% rat damage to ripening upland rice before harvest in 2011, and to the situation of the previous year (12.8%), rat damage was significantly reduced to an average of 4.3% in rice fields of the treatment villages. The incidence of rat-infested rice storage huts dropped significantly from an average of 86% in 2010 to 3.5% in 2011 in the treatment villages. Villagers from Houaphanh culled a total of 73,088 rodents over a period of about nine months, which included mainly black rats (Rattus rattus). Because the program phased out before harvest in 2011, potential losses due to rodents were predicted based on yield-damage relationships of the crop year 2010. The predicted average reduction of yield loss for 2011 was 55%, or 417.6 kg ha⁻¹, in the treatment villages when compared to the controls. The program implemented principles of ecologically-based rodent management (EBRM), the components of which are discussed. In conclusion, EBRM could be helpful in stemming as what was observed as high chronic rodent populations in the uplands of Laos. True outbreaks will require development of a suitable forecast system.     

黄板对大田葡萄二黄斑叶蝉越冬成虫的诱杀效果

[目的]明确不同类型黄板对大田葡萄二黄斑叶蝉越冬成虫的诱杀效果。[方法]研究了2种市售黄板(北京中捷黄板和浙江台州黄板)和1种自制黄板对葡萄二黄斑叶蝉越冬代成虫的大田诱杀效果。[结果]2种市售黄板的诱杀效果好于自制黄板;3种黄板正、反两面对该虫越冬代成虫的诱虫效果差异不显著;3种黄板大田诱杀双翅目、鞘翅目昆虫的效果最好,但对天敌昆虫具有一定杀伤力。[结论]为探索葡萄园无公害防治技术提供了理论依据。     

不同颜色粘虫板及食物诱集剂对蓝莓黑腹果蝇的诱集效果

[目的]寻找黑腹果蝇高效、低毒和安全的生物防治措施,为黑腹果蝇发生测报及有效防控提供参考。[方法]研究不同颜色粘虫板及食物诱集剂对蓝莓黑腹果蝇的田间诱集效果。[结果]蓝色粘虫板和葡萄、香蕉和糖醋酒液引诱剂诱捕黑腹果蝇的效果最佳。[结论]综合因素考虑,可使用蓝色粘虫板与糖醋酒液引诱剂相结合的方式防治黑腹果蝇。     

Exploring overlooked components of remote South-east Pacific oceanic islands: Larval and macrobenthic assemblages in reef habitats with distinct underwater soundscapes

1. Identifying the diverse assemblage of species inhabiting rocky and coral reef habitats in isolated oceanic environments, and the important sound cues emitted from the reef, are crucial components to understand how species locate suitable habitats for the completion of their life-cycle and, thus, the functioning of these vulnerable ecosystems.
2. Recent field information suggests that the majority of reef biodiversity comprises small cryptic invertebrates; however, knowledge on these small components is extremely scarce.
3. The present study used light attraction methods to explore the diversity of larval, post-larval and macrobenthic cryptic fauna, and hydrophones to characterize the natural soundscape of rocky and coral reef habitats at the Robinson Crusoe island (Juan Fernandez Archipelago; 33°38′S, 78°50′W), and Rapa Nui (Easter Island; 27°7′S, 109°21′W), respectively.
4. Pelagic collections found important site-specific patterns and identified two main species assemblages: early-life stages (e.g. eggs, larval and juvenile stages of crustaceans, molluscs, and fishes) and emerging macrobenthos (e.g. demersal zooplankton such as peracarid crustaceans, ostracods, copepods, and polychaetes), with the latter contributing between 73 and 98% to the total catches.
5. The soundscape records showed marked differences among sites and seasons at Robinson Crusoe island, with variable differences found between day and night. However, at Rapa Nui, there were no differences between sites, but the ambient sound was higher at night possibly due to higher snapping shrimp activity.
6. This information highlights the importance of considering small-scale (site-to-site) patterns when evaluating overlooked components of diversity (i.e. biological or acoustic) in oceanic habitats, and provides the basis for understanding the importance of natural noise in the settlement of most reef-associated species, crucial features for the conservation of these remote and vulnerable ecosystems.

     

Area-wide management of Aedes albopictus: choice of study sites based on geospatial characteristics, socioeconomic factors and mosquito populations

BACKGROUND: Aedes (Stegomyia) albopictus (Skuse), the Asian tiger mosquito, is an introduced invasive species in the United States that is responsible for a significant proportion of service requests to local mosquito control programs. This container‐utilizing mosquito is refractory to standard mosquito abatement measures in the United States. This study is part of a USDA‐ARS project to develop an area‐wide management strategy for Ae. albopictus. The goal was to identify three study sites, similar in socioeconomic parameters, geography and Ae. albopictus abundance, in urban and suburban areas in Mercer and Monmouth counties in New Jersey. Prior service requests and light trap counts and also detailed county maps were used to chose nine preliminary sites (four in Mercer and five in Monmouth) where weekly surveillance for Ae. albopictus was performed throughout the 2008 active season. RESULTS: Although outliers were detected, socioeconomic variables in the study sites within each county were fairly consistent. Ae. albopictus abundance was associated with poverty levels and had the highest maxima in Mercer, although average mosquito abundance was similar in urban Mercer and suburban Monmouth. CONCLUSION: Three study sites in each county were identified for future studies. The summer‐long surveillance also revealed socioeconomic variables critical for the development of integrated mosquito management. Copyright © 2011 Society of Chemical Industry