Long-term region-wide declines in Caribbean corals

We report a massive region-wide decline of corals across the entire Caribbean basin, with the average hard coral cover on reefs being reduced by 80%, from about 50% to 10% cover, in three decades. Our meta-analysis shows that patterns of change in coral cover are variable across time periods but largely consistent across subregions, suggesting that local causes have operated with some degree of synchrony on a region-wide scale. Although the rate of coral loss has slowed in the past decade compared to the 1980s, significant declines are persisting. The ability of Caribbean coral reefs to cope with future local and global environmental change may be irretrievably compromised.     

Spread of diadema mass mortality through the Caribbean

Populations of the ecologically important sea urchin Diadema antillarum suffered severe mass mortalities throughout the Caribbean. This mortality was first observed at Panama in January 1983; by January 1984 it had spread to the rest of the Caribbean and to Bermuda. The sequence of mortality events in most areas is consistent with the hypothesis that the causative agent was dispersed by major surface currents over large distances. However, some of the late die-offs in the southeastern Caribbean do not fit this pattern. Several lines of indirect evidence suggest that the phenomenon is due to a water-borne pathogen. If so, this is the most extensive epidemic documented for a marine invertebrate.     

Proximal cretaceous-tertiary boundary impact deposits in the Caribbean

Trace element, isotopic, and mineralogic studies indicate that the proposed impact at the Cretaceous-Tertiary (K-T) boundary occurred in an ocean basin, although a minor component of continental material is required. The size and abundance of shocked minerals and the restricted geographic occurrence of the ejecta layer and impact-wave deposits suggest an impact between the Americas. Coarse boundary sediments at sites 151 and 153 in the Colombian Basin and 5- to 450-meter-thick boundary sediments in Cuba may be deposits of a giant wave produced by a nearby oceanic impact. On the southern peninsula of Haiti, a approximately 50-centimeter-thick ejecta layer occurs at the K-T boundary. This ejecta layer is approximately 25 times as thick as that at any known K-T site and suggests an impact site within approximately 1000 kilometers. Seismic reflection profiles suggest that a buried approximately 300-km-diameter candidate structure occurs in the Colombian Basin.     

Caribbean eocene volcanism and the extent of horizon a

Layer A and its correlative layer A" in the Caribbean have been interpreted as chert layers produced by Eocene volcanism. Exposures of Eocene volcanic rocks in Puerto Rico and the Dominican Republic may represent layer A interbedded with coarser volcanic debris and preserved near early Tertiary volcanic centers.     

Hyalinea baltica and the Plio-Pleistocene Boundary in the Caribbean Sea

The foraminifer Hyalinea baltica is found for the first time in sediments from the western Caribbean Sea. Its relationship to the Plio-Pleistocene boundary and to other criteria used to define this boundary is examined, with the result that a strict adherence to the classical definition is urged.     

Signs test applied to Caribbean deep-sea core a 172-6

Caribbean core A 172-6 of the Lamont Geological Observatory series has been subjected to a nonparametric test for trend in order to examine the distribution of selected elements and of published paleotemperature data throughout a core length of 9.35 meters. First appearance of trend below top of core has been calculated, and the results of these tests are discussed.     

加勒比松 3 个变种种源试验初报

【目的】弥补当前加勒比松遗传范围窄的不足,拓宽其遗传基础,以利于开展加勒比松杂交育种进行种质创制。【方法】采用随机完全区组设计,将 22 个种源 / 种批的加勒比松 3 个变种、湿地松种质资源种植于广东省台山市红岭种子园,分别于种植后 1 年、4 年调查生长量,将数据用于方差分析、多重比较、遗传参数估算、相关性分析等。【结果】不同树种（变种）、种源间生长差异极显著,到 4 年生时,古巴加勒比松的保存率最低（44.76%）,湿地松的保存率最高（74.95%）。对种源数量最多的洪都拉斯加勒比松进行遗传参数估算,结果显示树高、胸径、单株材积的广义遗传力介于 0.8044~0.9822 之间,表明开展洪都拉斯加勒比松种源选择可靠性较高。与台山湿地松对照相比,巴哈马加勒比松巴西种源的生长表现最好、单株材积增益达到72.73%,洪都拉斯加勒比松澳大利亚种源次之、单株材积增益为 65.85%,而古巴加勒比松的 3 个种源单株材积增益均为负值,表明古巴加勒比松变种不适宜在台山种植。【结论】国内加勒比松资源由于遗传基础狭窄,其子代在生长方面开始出现衰退现象,本研究引进的巴哈马加勒比松和洪都拉斯加勒比松资源变异丰富,部分种源在台山生长表现优异,可一定程度拓宽国内加勒比松遗传基础,为湿加松新种质创制提供宝贵材料。     

国内湿加松文献分析及对海南省湿加松发展启示

利用CNKI对我国湿加松的相关研究进行检索和整理,论述了湿加松在我国的发展现状和前景,并对比湿加松在海南省引种、繁育、生长和利用的相关研究结果,介绍了湿加松在海南的发展现状和综合开发利用途径,以期为其在海南省的推广和应用提供理论依据。     

African droughts and dust transport to the Caribbean: climate change implications

Great quantities of African dust are carried over large areas of the Atlantic and to the Caribbean during much of the year. Measurements made from 1965 to 1998 in Barbados trade winds show large interannual changes that are highly anticorrelated with rainfall in the Soudano-Sahel, a region that has suffered varying degrees of drought since 1970. Regression estimates based on long-term rainfall data suggest that dust concentrations were sharply lower during much of the 20th century before 1970, when rainfall was more normal. Because of the great sensitivity of dust emissions to climate, future changes in climate could result in large changes in emissions from African and other arid regions that, in turn, could lead to impacts on climate over large areas.     

粤西8年生加勒比松施肥效果研究

【目的】研究阳江8年生古巴加勒比松Pinus caribaea var.caribaea人工林对氮磷钾不同配比及与微量元素混施的肥效反应。【方法】设定17个氮磷钾不同配比及与微量元素混施的追肥处理,15个月后监测古巴加勒比松的生长量和养分。【结果】协方差分析结果表明,N(21.5 g·株~(-1))、P_2O_5(30 g·株~(-1))的配比处理效果最好。单株施用50 g尿素+250 g钙镁磷肥+25 g氯化钾处理15个月后,单株材积增量比空白对照平均可提高23.6%。加磷(N_2P_1K_2、N_2P_2K_2)比无磷处理(N_2P_0K_2)的生长量显著增大。另外,在氮磷钾相同情况下,添加硼对材积也有显著促进作用。【结论】磷与硼是影响郁闭后加勒比松生长的重要元素。氮磷配比对肥效反应有重要调控作用。