Mission report: a strategy to inventory, characterize, and monitor the marine region within and around the National Park and Monument boundaries of St. John, USVI, July 21- July 31, 2008

The intent of this field mission was to continue ongoing efforts: (1) to spatially characterize and monitor the distribution, abundance and size of both reef fishes and conch within and around the waters of the Virgin Islands National Park (VIIS) and newly established Virgin Islands Coral Reef National Monument (VICR), (2) to correlate this information to in-situ data collected on associated habitat parameters, (3) to use this information to establish the knowledge base necessary for enacting management decisions in a spatial setting and to establish the efficacy of those management decisions. This work is supported by the National Park Service and NOAA’s Coral Reef Conservation Program’s Caribbean Coral Reef Ecosystem Monitoring Project. The report highlights the successes of this mission.

A report on the fisheries of Uganda investigated by the Cambridge Expedition to the East African Lakes, 1930-31

There was very little previous information to use as a basis for work on Lakes Edward and George, but fortunately the region had been mapped in some detail by the Uganda-Congo Boundary Commission of 1906-08. This map served as a satisfactory foundation, but the western Congo shoreline of Lake Edward was inserted only by a dotted line, and a number of inaccuracies, particularly with regard to the islands and littoral of L. George, came to light during our survey.

用于研究快速扫视对瞳孔光反射调制作用的新方法

瞳孔与光反射系统和快速扫视系统在解剖学和功能上都有着紧密联系，但是快速扫视系统对瞳孔的光反射系统是否有调制作用尚无报道。研究这两个系统间的调制作用，必须了解光刺激不均匀和近反应对瞳孔直径变化是否有影响。该研究以人为被试，设计了一种全新的实验方法，研究光刺激不均匀和近反应对瞳孔直径变化的影响。实验方法：将被试的一只眼用密闭的眼罩罩住给予脉冲光刺激，刺激由位于眼罩内全视野范围水平排列的一排发光二极(lightemitting diodes，LEDs)给出，被试的另一只眼用来记录眼动和瞳孔直径的变化，研究水平方向的快速扫视对瞳孔对光反射时瞳孔直径变化的影响。实验结果：比较被试注视视野内不同位置的瞳孔对光反射相对收缩率无显著差异（P=0.148, 非配对样本t 检验）。结论：该方法消除了光刺激不均匀和近反应对瞳孔直径变化的影响，可用于研究快速扫视系统对瞳孔光反射系统间的调制作用。

Habitat degradation of Rhinopithecus bieti in Yunnan, China

Black-and-white snub-nosed monkeys (Rhinopithecus bieti) are endemic to the Trans-Himalayas in Northwest Yunnan and Southeast Tibet between the upper Yangtze and Mekong Rivers. Based on field surveys and previous reports, we identified the dark-coniferous forest, the mixed coniferous and broadleaf forest, and oak patches as suitable habitats (SH) for the monkeys. Summer grazing lands (SGL), which were made by local people cutting and burning the dark-coniferous forest at the high altitude belt, replaced SH. To have a general view of the status of the SH in Yunnan, we estimated the areas of SH and SGL from satellite images in 1997, and compared with areas estimated from aerial photo-based maps (ca. 1958). The work resulted in: 1) the area of SH was 4,169 km(2) in 1997; 2) SGL was 1,923 km(2); 3) during the past 40 years, the area of SH decreased by 31% (1,887 km(2)), and SGL increased by 204% (1,291 km(2)); and 4) the mean size of forest patches decreased from 15.6 to 5.4 km(2). In addition, the area of SGL is positively correlated to local human population (R-2 greater than or equal to0.53), implying that the reduction and fragmentation of habitat for Rhinopithecus bieti is a result of population growth of humans, who mostly employ traditional modes of production. Only 11 monkey groups remained in the changing habitat. Considering that forests at lower elevation were also encroached upon by farmlands in a similar way, the forest ecosystem is highly threatened. The destruction will continue unless there is a change in the mode of production in the region.

Molecular beam epitaxy growth and photoluminescence study of room temperature 1.31 mu m (InyGa1-yAs/GaAs1-x Sb-x)/ GaAs bilayer quantum wells

Molecular beam epitaxy (MBE) growth of (InyGa1-yAs/GaAs1-xSbx)/GaAs bilayer quantum well (BQW) structures has been investigated. It is evidenced by photo luminescence (PL) that a strong blue shift of the PL peak energy of 47 meV with increasing PL excitation power from 0.63 to 20 mW was observed, indicating type II band alignment of the BQW. The emission wavelength at room temperature from (InyGa1-yAs/GaAs1-xSbx)/GaAs BQW is longer (above 1.2 μ m) than that from InGaAs/GaAs and GaAsSb/GaAs SQW structures (1.1 μ m range), while the emission efficiency from the BQW structures is comparable to that of the SQW. Through optimizing growth conditions, we have obtained room temperature 1.31 μ m wavelength emission from the (InyGa1-yAs/GaAs1-xSbx)/GaAs BQW. Our results have proved experimentally that the GaAs-based bilayer (InyGa1-yAs/GaAs1-xSbx)/GaAs quantum well is a useful structure for the fabrication of near-infrared wavelength optoelectronic devices. © 2005 Elsevier B.V. All rights reserved.

Influence of growth parameters of frequency-radio plasma nitrogen source on extending emission wavelengths from 1.31 mu m to 1.55 mu m GaInNAs/GaAs quantum wells grown by molecular-beam epitaxy

High (42.5%) indium content GaInNAs/GaAs quantum wells with room temperature emission wavelength from 1.3 mu m to 1.5 mu m range were successfully grown by Radio Frequency Plasma Nitrogen source assisted Molecular Beam Epitaxy. The growth parameters of plasma power and N-2 How rate were optimized systematically to improve the material quality. Photoluminescence and transmission electron microscopy measurements showed that the optical and crystal quality of the 1.54 mu m GaInNAs/GaAs QWs was kept as comparable as that in 1.31 mu m.

长白山阔叶红松林生态系统碳密度对采伐干扰的响应研究

本研究以长白山地区原始和次生的阔叶红松林为对象，在2007和2008年共建立了8种类型10块1 ha样地。通过野外调查和取样分析，得到各样地森林生态系统的植物、枯死物和土壤碳密度值，并结合采伐样地经营历史情况（采伐时间和强度），得到长白山地区原始阔叶红松林生态系统碳密度参考值和次生阔叶红松林生态系统碳密度对采伐强度和植被恢复时间的响应特征。在此基础上，通过建立阔叶红松林乔木碳密度与生态系统碳密度的回归关系，并结合露水河林业局3个时期（1987、1995和2003年）的小班数据和原始林碳密度参考值，估算露水河林业局林业用地3个时期和潜在的碳储量。主要研究结果如下： （1）原始阔叶红松林生态系统碳密度参考值：植被、枯死物、土壤和生态系统碳密度值分别为149.18±54.57、20.93±14.33、156.39±14.99、326.50±34.52 t•ha-1。其中下木层、乔木层碳密度分别是1.55±0.74，147.63±54.39 t•ha-1；粗木质残体和枯枝落叶碳密度分别是15.64±13.66、5.29±1.72 t•ha-1；0-50 cm的各层土壤碳密度分别为62.14±6.31、46.17±10.25、27.82±6.20、12.57±4.67、7.69±2.20 t•ha-1。 （2）原始阔叶红松林生态系统碳密度对采伐干扰的响应特征为：采伐干扰均会减少生态系统碳密度；其中植被碳库对采伐干扰最为敏感且碳密度值均减少，采伐强度直接决定植被碳密度的减少程度和恢复时间；枯死物碳库对采伐干扰最不敏感且碳密度值是先增加后减少，采伐强度和植被恢复时建群树种决定枯死物碳密度的变化程度；土壤碳库对高强度采伐干扰敏感，采伐强度决定土壤碳密度是否发生变化。 （3）估算露水河林业局林业用地在1987、1995、2003年和潜在的森林生态系统碳储量分别为29.58×106 t、27.55×106 t、30.46×106 t和38.75×106 t。