近30年毛乌素沙区的气候与厄尔尼诺/拉尼娜事件的相关分析

本文利用毛乌素沙区 8个气象站近 30年的气象资料 ,运用MicrosoftExcel2 0 0 0和X2 检验 ,分析了该区近30年来的气候变化特点及其与厄尔尼诺 /拉尼娜事件的相关程度。研究表明 :近 30年来 ,毛乌素沙区的气候总体上呈暖干化趋势 ,降水量减少 ,降水的稳定性增强 ,气温升高 ,气温的波动性增大 ,且存在明显的区内差异 ;厄尔尼诺事件对毛乌素沙区的降水量影响程度较大 ,厄尔尼诺年降水量明显减少 ,且下一年降水量增多 ;拉尼娜事件对毛乌素沙区的气温有一定影响 ,拉尼娜年气温相对降低 ;拉尼娜年降水量略有增加趋势 ,厄尔尼诺年气温有所升高 ,但都达不到统计上的相关水平。     

Spatial and temporal variation in the Argentine ant edge effect: Implications for the mechanism of edge limitation

One consequence of human land-use is the exposure of native communities to invasive human commensal species along edges. Argentine ants (Linepithema humile) invade a variety of habitats in California with consequent dramatic declines in native ants. In coastal southern California, USA Argentine ants appear to be an edge effect in small habitat fragments [Suarez, A.V., Bolger, D.T., Case, T.J., 1998. Effects of fragmentation and invasion on native ant communities in coastal southern California. Ecology 79, 2041-2056]. They invade fragments from the urban edge, but only penetrate coastal sage scrub (CSS) habitat to a distance of approximately 200 m. Using pitfall sampling in edge (<250 m from the urban edge) and interior (>600 m from the edge) habitat I tested whether there is also an Argentine ant edge effect in the largest blocks of habitat in the landscape and investigated patterns of spatial and temporal variation in native and Argentine ants. Argentine ants were common in coastal sage scrub habitat within 250 m of urban edges, but rare in interior areas. Correspondingly, native ants were significantly less abundant and diverse in edge areas as compared to interior. Over the period 1997-2000 Argentine ants did not become more abundant in interior habitat suggesting it will remain a refuge for native ants. Argentine ant abundance in edge plots varied greatly among years and sites. Annual variation in abundance was positively related to annual rainfall. Increased soil moisture near edges due to urban runoff has often been suggested as the mechanism that allows the invasion of edge but not interior habitat. This hypothesis predicts that edge habitat downslope of the urban edge should support invasions of higher abundance and greater spatial penetration than habitat upslope. However, I found that edge slope did not predict the extent of invasion, whereas, soil type did. Coarse, well-drained soils supported an Argentine ant invasion of lower abundance and lesser spatial penetration than soils that should retain more moisture. These patterns of spatial and annual variation are more consistent with a biotic flow mechanism where ants move from urban habitat into CSS sites that are temporarily favorable, rather than an abiotic flow where urban runoff causes a physical change to CSS habitat near edges. This invasion affects a substantial area of habitat, however, the inability of Argentine ants to invade interior habitat suggests that refugia for native ants will persist if large unfragmented blocks of habitat are maintained.     

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.     

ENSO事件对安徽省气候变化和旱涝灾害的影响

本文选用1960—2012年安徽省降水与气温数据资料,利用线性倾向估计法、反距离加权插值法、相关分析法和X²拟合检验等方法分析了近53年来安徽省气温和降水的时空特征以及ENSO对气候变化和旱涝灾害的影响。结果发现：（1）近53年来,El Nino事件和La Nina事件的出现频数分别为16次和15次,El Nino事件多发生在春、夏2季,结束于冬季;La Nina事件多发生在夏、秋2季,结束于春、冬季;（2）从时间上看,近53年来安徽省年降水量呈微弱的增加趋势;年平均气温呈明显的上升趋势,20世纪90年代后期升温趋势尤为明显;（3）空间上,降水量呈南多北少的分布特征,淮河以北降水呈减少趋势,而淮河以南则呈增加趋势;气温的高值中心位于皖南山区和大别山区;（4）El Nino事件使得降水量减少,气温增加,而La Nina事件使得降水量增加,气温降低,并且存在一定程度的滞后性;（5）El Nino事件和La Nina事件分别与安徽省的旱灾和涝灾存在显著的关系,旱涝灾害大多发生在ENSO事件年的当年、次年或前一年,且旱灾在连续性的El Nino事件年发生的概率更大。     

Unanticipated effect of climate change on an aquatic top predator of the Atlantic rainforest

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