Intertidal seagrass in Ireland: Pressures,WFD status and an assessment of trace element contamination in intertidal habitats using Zostera noltei

Intertidal seagrass has been selected as a Biological Quality Element for the assessment of ecological status under the Water Framework Directive. In Ireland, two species of seagrass, Zostera marina and Z. noltei occur in intertidal habitats. This study presents the first comprehensive assessment of the distribution and Water Framework Directive status of intertidal seagrass in the Republic of Ireland and Northern Ireland. Most of the areas assessed, using the Water Framework Directive-compliant assessment tool, have a status of HIGH or GOOD. Only two areas were found to have a status less than GOOD and in both, the cause for the decline was smothering by opportunistic foliose green macroalgae. Linear regression showed a relationship between pressure index scores and Ecological Quality Ratio, showing the relevance of the index as a metric of anthropogenic pressure. Trace element concentrations were examined in Z. noltei tissues and Trace Element Pollution Index values were calculated. The relationship between Trace Element contamination and Water Framework Directive status was examined but the results showed little correlation. However, a relationship between the pressure index and trace element contamination was obtained. This assessment provides the most comprehensive overview of intertidal seagrass beds in Ireland and establishes a strong baseline for ongoing monitoring and assessment under the Water Framework Directive. The data provide key information on the pressures affecting these valuable habitats which will assist in the development of measures to improve and protect our transitional and coastal waters.     

四种蕨类植物根际土壤中VA菌根真菌孢子种群组成和季相变化

对４ 种移栽到温室中的蕨类植物根际土壤中的ＶＡ 菌根真菌孢子种群组成和季相变化进行了研究, 结果发现, ＶＡ菌根真菌孢子的产生具有明显的宿主依赖性和季相变化。在相同气候条件下, 不同植物根际土壤中的ＶＡ菌根真菌种群组成不同; 同种ＶＡ 菌根真菌在不同宿主植物根际土壤中, 孢子的丰富度有很大的差异。本文对影响ＶＡ菌根真菌孢子种群组成和季相变化的因素进行了讨论。     

Population of goats related to climate in western India: an ecological assessment

Western India experiences arid to dry subhumid ecoclimate. Aridity increases from east to west to the Great Indian Desert or Thar Desert. The desert economy is animal based and goats are the most common livestock; density of goats increases with increase in aridity. There are large morphological variations in goats warranting the recognition of population differences throughout the region. The present investigations were therefore undertaken to see whether there are population differences and, if so, to establish the populations on a sound ecological basis. Eleven physical measurements of the animals were made in the fields of western India in a total of 518 animals (255 adults). Five populations were initially segregated by means of a scatter diagram. Population differences were confirmed by mathematical treatments using analysis of variance (one-way and two-way) and Students-Newman-Keuls test, which yields a critical comparison among means. Discriminant analysis was used to determine whether the goat populations differed significantly between the five climo-edaphic-vegetational zones. Each population was designated according to the locality having the greatest density as: POP1Ku, POP2Sa, POP3Jh, POP4Ga, POP5Pa. The five populations occurring in distinct climo-edaphic-vegetational zones or ecological niches in western India may be referred to as ecotypes.     

Unraveling Seasonality in Population Averages: An Examination of Seasonal Variation in Glucose Levels in Diabetes Patients Using a Large Population-based Data Set

It has been shown that the population average blood glucose level of diabetes patients shows seasonal variation, with higher levels in the winter than summer. However, seasonality in the population averages could be due to a tendency in the individual to seasonal variation, or alternatively due to occasional high winter readings (spiking), with different individuals showing this increase in different winters. A method was developed to rule out spiking as the dominant pattern underlying the seasonal variation in the population averages. Three years of data from three community-serving laboratories in Israel were retrieved. Diabetes patients (N?=?3243) with a blood glucose result every winter and summer over the study period were selected. For each individual, the following were calculated: seasonal average glucose for all winters and summers over the period of study (2006–2009), winter-summer difference for each adjacent winter-summer pair, and average of these five differences, an index of the degree of spikiness in the pattern of the six seasonal levels, and number of times out of five that each winter-summer difference was positive. Seasonal population averages were examined. The distribution of the individual's differences between adjacent seasons (winter minus summer) was examined and compared between subgroups. Seasonal population averages were reexamined in groups divided according to the index of the degree of spikiness in the individual's glucose pattern over the series of seasons. Seasonal population averages showed higher winter than summer levels. The overall median winter-summer difference on the individual level was 8?mg/dL (0.4?mmol/L). In 16.9% (95% confidence interval [CI]: 15.6–18.2%) of the population, all five winter-summer differences were positive versus 3.6% (95% CI: 3.0–4.2%) where all five winter-summer differences were negative. Seasonal variation in the population averages was not attenuated in the group having the lowest spikiness index; comparison of the distributions of the winter-summer differences in the high-, medium-, and low-spikiness groups showed no significant difference (p?=?.213). Therefore, seasonality in the population average blood glucose in diabetes patients is not just the result of occasional high measurements in different individuals in different winters, but presumably reflects a general periodic tendency in individuals for winter glucose levels to be higher than summer levels. (Author correspondence: anneke@clalit.org.il)     

珀氏长吻松鼠和赤腹松鼠在保护区与非保护区各年龄松林内的种群动态

2004年6~7月,在云南省大理白族自治州苍山和洱海国家自然保护区选取4种年龄段(6~10、11~15、16~20、31~40年)的松林和保护区周围的非保护区选取7种年龄段(1~5、6~10、11~15、16~20、21~30、31~40、50年以上)的松林,每种松林设3个重复,共33个样地,在样地内随机选取3个5m×5m的样方,调查并记录样方内草本植物和灌木的种类、数量、覆盖度。在每个样地按5条样线布笼100个捕捉小兽,每天检查捕获的种类和数量。计算珀氏长吻松鼠和赤腹松鼠在小兽群落中物种优势度、时间生态位宽度、两种小兽的时间生态位重叠度;用逐步回归分析两种松鼠与松林栖境因子的关系。上述结果表明,在保护区珀氏长吻松鼠出现的时间早于(6~10年的松林开始捕获到)赤腹松鼠(16~20年的松林内开始捕获到);在非保护区,分别在31~40年和21~30年的松林内才捕到珀氏长吻松鼠和赤腹松鼠。保护区31~40年的松林内珀氏长吻松鼠和赤腹松鼠种群数量分别是同年龄段非保护区松林的3倍和3·75倍。松林底层的灌木对两种小兽的种群数量有重要影响。珀氏长吻松鼠种群数量与灌木密度呈正相关;赤腹松鼠种群数量与灌木覆盖度呈正相关,而与草本植物覆盖度呈负相关。非保护区树底植被的异质性降低,延迟了两种松鼠在松林里建立种群的时间。     

Life History,Reproduction, Growth,Population Dynamics and Production of Gammarus aequicauda (Crustacea: Amphipoda) at Extremely Low Salinities in a Mediterranean Lagoon

Aspects of the biology of Gammarus aequicauda were studied at extremely low salinities (0.3–5.7 psu) in Monolimni Lagoon, N. Aegean Sea. Samples were collected monthly from February 1998 to February 1999. Breeding occurred continuously but peaked in late spring, late summer and autumn and three cohorts were produced. The spring and summer cohorts showed fast growth (0.15 mm d^–1), accelerated maturity and life span of about three and seven months respectively, while the overwintering cohort showed a life span of about nine months. The largest individual had a body length of 23.6 mm. Mean brood size was 54.5 early embryos, while the intramarsupial loss was 46%. Population density sharply increased in late spring, summer and autumn. Secondary production calculated by Hynes' method gave a mean annual density of 1077.4 ind. m^–2, a mean annual crop (B) of 2.93 g DW m^–2, an annual production (P) of 35.03 g DW m^–2 and a P: B ratio of 11.96. Gammarus aequicauda showed a life‐history pattern similar to those previously reported for this species at higher salinity environments with comparatively large final body length and high growth rate during summer, brood size and P: B ratio, but with high embryo loss as well. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)