Synchronicity in southern hemisphere squid stocks and the influence of the Southern Oscillation and Trans Polar Index

Squid are short lived, with highly labile populations that respond rapidly to changes in environmental conditions. This makes them a good model for studying the response of recruitment processes to environmental signals. This study examines the influence of the Southern Oscillation Index (SOI) and Trans Polar Index (TPI) on the environment and abundance of six species of commercially important squid from the southern hemisphere, all linked to major current systems connected by the Antarctic Circumpolar Current: Dosidicus gigas (Southeast Pacific), Loligo vulgaris reynaudii (Southeast Atlantic), Nototodarus sloanii, N. gouldi (Southwest Pacific), Illex argentinus and L. gahi (Southwest Atlantic). All fisheries displayed a high level of inter‐annual variability and a degree of synchronicity was seen to occur in the abundance of the three Pacific species. The SOI signal was reflected in the environment of each fishery, particularly in Pacific regions. Both indices are correlated with squid abundance, particularly during the early life history stages (SOI) and adult stages (TPI), suggesting some degree of latitudinal separation, with juveniles potentially influenced by environmental variability at lower latitudes and adults at higher latitudes.     

湖北省马尾松人工林林分生长过程表的编制

根据３６０块标准地１９３株解析木资料，采用Ｃｈａｐｍａｎ－Ｒｉｃｈａｒｄｓ函数和二次项方程分别模拟平均树高和平均胸径的生长过程，运用迭代法分指数编制了湖北省马尾松人工林林分生长过程表。经预测检验，精度很高，可应用于湖北省马尾松人工林的经营。     

水稻“精苗稳前、控蘖优中、大穗强后”超高产定量化栽培模式

【目的】寻求水稻稳定超高产的栽培模式。【方法】以早熟晚粳品种武粳15、常优1号为供试材料,其它栽培措施统一在最佳技术指标前提下,就氮肥运筹与穗肥施用叶龄期,设置了稳前优中强后、平衡促进和促前控中3种栽培模式,并以长江中下游地区单季稻大面积生产上的常规栽培模式为CK,对产量及其结构、群体生长发育动态以及根系活力等方面进行系统比较。同时,在江苏东海、兴化、高邮、常熟等地,以徐稻3号、常优1号、陵香优18、武粳15等品种为材料,进行(15—50)×667m2连片的稳前优中强后超高产栽培综合试验与扩大到100×667m2连片试验田上的生产性验证试验。【结果】2品种稳前优中强后、平衡促进2模式的实产均达到了超高产水平(≥750kg/667m2)。与CK相比,稳前优中强后、平衡促进2模式每穗粒数多、群体颖花量大,单位面积穗数、结实率和千粒重则与之相当;2模式的群体于有效分蘖临界叶龄期准时够苗,高峰苗出现在拔节期,且数量适中(适宜穗数的1.3—1.4倍),此后群体平缓消减,至抽穗期基本稳定,最终成穗率显著高于CK;其群体LAI动态与茎蘖动态趋势基本一致,最大LAI均出现在孕穗期,为8.0—8.5,成熟期仍保持3.5—4.0;群体光合势与干物质积累,2模式在生育前期(移栽—拔节期)较CK低,中期(拔节—抽穗期)与CK相当,后期(抽穗—成熟期)显著高于CK;2模式在拔节期的根系干重与CK相当,抽穗期和成熟期则显著高于CK,而这3个时期的根冠比均显著高于CK,其抽穗后(抽穗—腊熟期)的根系平均伤流量与颖花根流量均显著高于CK。同时,连续2年多地的稳前优中强后超高产综合栽培试验以及后3年扩大到100×667m2连片试验田上的生产性验证试验,实产均达800kg/667m2左右。【结论】揭示了水稻超高产栽培的根本在于"强支撑、扩库容、促充实";提出了水稻精苗稳前、控蘖优中、大穗强后的超高产定量化栽培模式。     

Ecological variations and El Niño effects off the southern coast of the Korean Peninsula during the last three decades

To explore ecosystem response to environmental changes, we investigated interannual and decadal changes in the marine ecosystem using data collected from the southern coast of the Korean Peninsula during the 1960s–1990s. Water properties such as sea surface temperature (SST) and salinity in April did not show large variation during the 1970s, but a relatively cool water mass appeared from the early to mid 1980s and a warm water mass replaced it after 1989. Chl a concentration in April, which was converted from Secchi disc information, was low (mean=1.18 mg m⁻³) during the period 1968–1980 excluding 1974, but there was a period of greater biomass for 7 years from 1981 (mean=2.78 mg m⁻³). A negative correlation ( r =−0.387, P  < 0.05) between SST and chl a in April matched high chl a during the low-SST period in the early and mid 1980s. Annual zooplankton biomass ranged from 37 to 132 mg m⁻³, but abundance was frequently high after 1984 and low during 1972–1982. The most representative pelagic fishes in the South Sea seemed to respond to the increase in planktonic organisms. Anchovy, mackerel and sardine increased in abundance since the mid 1970s. High catches of anchovy and mackerel lasted until the 1990s, whereas sardine decreased after the early 1990s. From the matrix of simple correlation coefficient, the Southern Oscillation Index (SOI) exhibited a high correlation with SST in December in the study area ( P  < 0.05). Catches of anchovy and mackerel were positively correlated with chl a and zooplankton during their early life periods, as well as with SST in December.     

森林火灾重灾年与SOI异常变化关系的分析方法

根据福建省建阳市1955-1994年的森林火灾面积统计数据和1952-1994年南方涛动指数(SO I),运用异常度辨识法分析了建阳市森林火灾重灾年前后3 a的SO I异常度变化规律和特点.结果表明,前2 a和前3 a的SO I异常度值均接近显著异常水平,前1 a的异常度值为显著异常,说明异常度辨识法对于科学预测森林火灾重灾年有重要的参考价值.     

Using seasonal climate forecasts to improve maize production decision support in Zimbabwe

Maize production in marginal tropical regions is at great risk due to rainfall variability and climate change. Climate change is set to increase the variability and uncertainty of inter-annual rainfall. Farmers who depend on rainfed maize production for their livelihoods would therefore benefit from improved climate based forecasting of production likelihood. In this study we developed a simple maize production decision support tool for Masvingo by using seasonal climate forecasts and a crop model to forecast maize yields likelihood prior to the season. We follow up on earlier studies carried out in Zimbabwe which show that the El Nino Southern Oscillation (ENSO) can be used to forecast rainfall and maize yields in Zimbabwe. An ENSO based seasonal climate analysis tool (RAINMAN) was used to produce probabilistic monthly climate forecasts for Masvingo corresponding to the phases of the Southern Oscillation Index (SOI). The climate forecasts were used to run a crop model (AquaCrop) for a variety of scenarios relevant to maize production (monthly rainfall, cultivar selection, planting date, and fertility level). The results of the simulations were similar to those observed by Phillips et al. (1997) and formed the basis for the development of an operational decision support tool. Simulated maize yields varied from 1.2 t/ha to 5.8 t/ha. The simulated yields were higher than expected average yields in a marginal region like Masvingo especially under small holder farming. The work suggested that optimal use of forecasts may lead to improved maize production in Masvingo. The study set a platform for the development of operational climate based maize production decision support tools in Zimbabwe.     

中西太平洋金枪鱼围网自由鱼群渔场重心变动及其与南方涛动指数的关系

文章根据2013—2017年中国中西太平洋金枪鱼围网船队捕捞日志,利用捕捞自由鱼群作业位置、作业时间和渔获量等数据信息,分析了自由鱼群渔场重心月间变化、年际变化与南方涛动指数(South Oscillation Index,SOI)的关系。结果显示,渔获量较高的海域海表温度(Sea surface temperature,SST)高于29℃;自由鱼群的渔场重心主要分布介于160°E—175°W;2013—2015年渔场重心有逐年向东偏移的趋势,但无明显的月间变化规律;SOI为正值时,中西太平洋“暖池”较正常年份向西偏移,自由鱼群渔场重心亦明显向西偏移;反之,自由鱼群渔场重心较正常年份向东偏移。相关性分析显示SOI和月间渔场重心的经度之间呈负相关(相关系数为?0.27,P<0.05),表明金枪鱼围网渔场变动和异常气候的发生存在密切联系。研究结果对于掌握中西太平洋金枪鱼围网渔场变动规律具有一定参考价值。     

Fluctuation in abundance of larval anchovy and environmental conditions in coastal waters off south-western Taiwan as associated with the El Niño–Southern Oscillation

Monthly abundance ( CPUE ) of larval anchovy in the coastal waters off south-western Taiwan from 1980 to 1992 (156 months) fluctuated at intervals corresponding to the 4.3- and 2.2-year cycles of the southern oscillation index ( SOI ). Also, CPUE was significantly correlated with sea surface temperature with a time lag of 3 months and nearly significantly to river flow with a time lag of 4 months, which in turn correlated with SOI at lags of 13–14 months (cross-correlation and transfer function analyses). The results suggested the presence of linkage between recruitment of the larvae and ENSO episodes, perhaps through oceanographic and meteorological conditions that affect coastal upwelling and river discharge. The Kuroshio Current, which is the western extension of the North Equatorial Current, may be one of the important mechanisms of ENSO's teleconnections affecting local climate and fisheries in the western Pacific region.