十堰市城区耕地土壤养分变化分析

2009年在国家测土配方施肥项目实施过程中,调查与分析了十堰市耕地土壤养分状况,与1982年的第二次土壤普查结果比较,2009年十堰市土壤的速效钾含量基本持平,有机质与碱解氮含量呈上升趋势,有效磷含量大幅度上升,而土壤pH值则下降明显。此外,还剖析了十堰市耕地养分变化的原因,并提出了提升耕地土壤养分含量的措施。     

西双版纳热带雨林树种多度与丰富度空间分布特征

基于西双版纳20 hm2森林动态监测样地内直径≥1cm的树种资料,分析该样地树种多度(个体数)和丰富度(物种数)及其方差与变异系数在7个取样尺度(5 m×5 m,10 m×10 m,20 m×20 m,25 m×25 m,50 m×50 m,100 m×100 m,200 m×250 m)的变化规律。结果显示:(1)西双版纳热带雨林样地环境异质性较大,多度和丰富度随着尺度的增加均表现非线性增加。(2)多度的方差随尺度增加而线性增加;丰富度的方差与尺度都表现出非线性的关系。丰富度的方差在尺度100 m×100 m上最大。(3)多度、丰富度和多样性指数的方差、变异系数均大于随机分布模型拟合的数值,表明树种在样地内分布不是随机分布。总之,在生物多样性的保护和管理中要特别注意,尽管多度具有可加性,只有当环境异质性不大时用小尺度多度估计大尺度多度才比较可靠;丰富度的非线性变化使得一个尺度上生物多样性"热点",在另一个取样尺度上却可能为"冷点"。     

Climatic,Edaphic Factors and Cropping History Help Predict Click Beetle (Coleoptera: Elateridae) (Agriotes spp.) Abundance

It is assumed that the abundance of Agriotes wireworms (Coleoptera: Elateridae) is affected by agro-ecological factors such as climatic and edaphic factors and the crop/previous crop grown at the sites investigated. The aim of this study, conducted in three different geographic counties in Croatia from 2007 to 2009, was to determine the factors that influence the abundance of adult click beetle of the species Agriotes brevis Cand., Agriotes lineatus (L.), Agriotes obscurus (L.), Agriotes sputator (L.), and Agriotes ustulatus Schall. The mean annual air temperature, total rainfall, percentage of coarse and fine sand, coarse and fine silt and clay, the soil pH, and humus were investigated as potential factors that may influence abundance. Adult click beetle emergence was monitored using sex pheromone traps (YATLORf and VARb3). Exploratory data analysis was preformed via regression tree models and regional differences in Agriotes species’ abundance were predicted based on the agro-ecological factors measured. It was found that the best overall predictor of A. brevis abundance was the previous crop grown. Conversely, the best predictor of A. lineatus abundance was the current crop being grown and the percentage of humus. The best predictor of A. obscurus abundance was soil pH in KCl. The best predictor of A. sputator abundance was rainfall. Finally, the best predictors of A. ustulatus abundance were soil pH in KCl and humus. These results may be useful in regional pest control programs or for predicting future outbreaks of these species.     

Effects of non-native spruce plantations on small mammal communities in subarctic birch forests

Voles and shrews are key species in northern forest ecosystems. Thus, it is important to quantify to what extent new forestry practices such as planting of non-native tree species impact these small mammals. In northern Norway stands of coastal subarctic birch forests have increasingly been converted to non-native spruce stands during the last century. This leads to changes in the forest floor vegetation and soil conditions that can be expected to negatively impact the community of ground-dwelling small mammals. In this 10-year trapping study we contrasted seasonal small mammal population abundances in spruce plantations with four birch forest varieties. Six different small mammal species were trapped (in descending order of abundance; common shrew Sorex araneus, red vole Myodes rutilus, field vole Microtus agrestis, grey-sided vole M. rufocanus, pygmy shrew S. minutus and water shrew Neomys fodiens). None of the voles appeared to exhibit temporal dynamics resembling population cycles. The three most numerous species were clearly less abundant in the spruce plantations compared to the other forest types. Autumn abundances were most impacted by spruce plantations, indicating that growth rates in the reproductive season were more influenced than winter declines. Species associated with productive forest habitats (i.e. field vole and common shrew) were most impacted by tree species conversion. Still young spruce plantations inter-mixed with birch trees and the ecotone habitat, sustained small mammal abundances comparable to the native birch forests. This implies that managing spruce plantations to maintain a mix of different tree species and high spatial heterogeneity (i.e. more ecotones), will reduce the negative impacts on the small mammal community. On the contrary, if young spruce plantations, as they age become spruce monocultures covering larger parts of the landscapes than they do presently, the negative effects on small mammal communities may be larger than observed in the present study.     

Spatial and temporal abundance of the solanum fruit fly, Bactrocera latifrons (Hendel), in Morogoro,Tanzania

Bactrocera latifrons is a newly invasive pest species in eastern Africa. Surveys to determine the spatial and temporal abundance of this fruit fly in the Morogoro Region, Eastern Central Tanzania, were conducted from April 2007 to March 2008. The surveys involved trapping of adult flies and collection of host fruits to determine the emergence of adults. The results indicated that the population of B. latifrons was generally low but that adult flies were present throughout the survey period. The population of B. latifrons based on infestation rates and incidence in host fruits, seems to be relatively high during the wet seasons, probably because of availability of many hosts. However, the population of the pest as determined by trapping, indicated a low population but without a specific pattern. The pest shows minimal response to the used attractants. The surveys further indicate that B. latifrons is more abundant in low to medium altitude areas compared to high altitude areas. The results indicate that, because of its low population, B. latifrons might be a minor pest. Results further suggest the possibility of establishing B. latifrons free areas where export valued solanaceous crops can be grown, but further research over longer periods would be needed to establish this.     

Rove beetle (Coleoptera: Staphylinidae) communities in transgenic Bt (MON810) and near isogenic maize

Field experiments were conducted to investigate the mechanism of the underlying patterns (abundance, species richness, diversity and similarity) of rove beetles in transgenic Bt (MON810) and in near isogenic maize stands in Hungary. During the three-year (2001–2003) survey, 1538 individuals and 21 species were sampled with pitfall traps. The Cry1Ab protein expressed by the MON810 maize hybrid did not influence the overall community structure. After grouping staphylinids into guilds we found no significant differences for non-aphidophagous predators and parasitoids, whereas there were significantly and marginally significantly higher abundances for predators with aphids in their diet in isogenic maize stands in 2002 and 2003 respectively. The abundance of the prey Rhopalosiphum padi (L.) showed a high fluctuation between stands and years and was numerically higher only in isogenic stands in the second half of the maize-growing season. The abundance of predatory guilds including aphids in their diet did not correlate with the total annual number of R. padi in the same year, but there was a linear correlation in successive years.     

Quantifying conservation concern - Bayesian statistics, birds and the red lists

For species that are still widespread, obtaining accurate and precise measures of population change inevitably means gathering representative sample data rather than undertaking a complete census. In the UK, a system of raising ‘alerts’ utilises stochastic models for such data to identify species in rapid (>50%) or moderate (25-50%) decline across various temporal and spatial scales. Considerable improvements in interpretation can be made by explaining annual fluctuations in terms of explicit population models (rather than trends of an arbitrary mathematical form); through the simultaneous modelling of data from a complete or partial census with those providing information on the demographic rates employed in these models; and through adopting a Bayesian rather than a frequentist statistical approach. A Bayesian approach is natural for quantifying, in the form of a probability, the support provided by the data for assigning a species to each of the categories. Based on territory mapping and ringing data for the lapwing Vanellus vanellus, we describe such an approach. Trends are estimated more precisely than those under models previously employed in the alerts context. Some smoothing is induced, but realistic responses to years of severe weather are retained, and these are expressed also via model-averaged trends in key demographic parameters. We discuss the conservation implications for this declining species, and the wider potential arising from the ability to quantify confidence that population change has exceeded a threshold either generating conservation concern or justifying a subsequent programme of action for recovery.     

山东省乡镇尺度土壤肥力空间分布特征研究

乡镇尺度上的土壤肥力指标能够代表当地的基础地力,而且还可以有效地指导科学施肥。本研究选择山东省1504个农业乡镇为研究对象,通过主成分和空间聚类分析方法,研究了山东省土壤肥力空间分布规律,以及丰缺敏感区域。主要研究结果如下：（1）山东省乡镇尺度上土壤有机质、全氮、有效磷和速效钾的平均含量分别为(12.93±0.1) g/kg、(0.87±0.01) g/kg、(31.89±0.51) mg/kg 和(128.64±1.48) mg/kg;利用土壤质量综合评价方法,将山东省各个乡镇土壤肥力分为优、中和差3类,所占比例分别为14.20%、46.67%和39.13%;总体上,山东省土壤肥力质量处于中等偏下水平,中等及以下的乡镇占总体比例为85.8%。（2）山东省土壤肥力空间分布呈现北低南高的趋势,自西向东呈现先升高后下降的趋势。其中土壤肥力相对高的地区以中部为中心,成发散式、环形分布,且途经潍坊市中部—淄博市—临沂市东北及东南部—枣庄西部与济宁连接处,构成一个S 型;山东半岛东南部地区土壤综合系数较低,有机质和 速效钾为主要限制因子;中南部、西南部及东南部地区土壤肥力等级较低的主要原因是有效磷和速效钾的含量较低;西北和北部地区,土壤肥力主要限制因子为全氮和有效磷。本研究结果对有针对性地制订适宜山东省不同区域的土壤肥力提升方案具有指导意义。     

上海宝钢生态园林植物群落类型及丰富度

运用群落生态学方法对宝钢生态园林进行植物群落的类型、组成和丰富度调查,并提出模拟地带性植物群落,构建"近自然"群落和林地的建议。       

Variations in the abundance of Pacific saury (Cololabis saira) from the northwestern Pacific in relation to oceanic-climate changes

Effects of oceanic-climate changes on the abundance of Pacific saury (Cololabis saira) in the northwestern Pacific during the last half century were investigated. Abundance indices of both large and medium size groups exhibit interannual–decadal variations, but their patterns were different. The large and medium size groups of saury are corresponding to the recruitments of winter- and spring-cohort, respectively. The abundance of large size group saury was significantly correlated with the winter sea surface temperature (SST) in the Kuroshio region, whereas the medium size group saury showed high correlations with SST in the Kuroshio–Oyashio transition zone and the Oyashio region, indicating that the two size groups are affected by subtropical and subarctic environment, respectively. Significant negative correlation between the abundance index and the southern oscillation index (SOI) suggested that El Niño-southern oscillation (ENSO) events have marked impacts on the large size group saury. Subtropical high pressure index and far east zonal index also show high correlations with the abundance of both large and medium size group saury, indicating a linkage between large-scale atmospheric circulation and the abundance of saury. These correlations demonstrate that the abundance of Pacific saury is directly affected by the SST fields through large-scale atmosphere–ocean interactions from the equatorial Pacific to mid- and high-latitude areas such as El Niño events.