我国北方潮土玉米不同生长时期古菌群落结构和丰度的变化

采用16S rRNA基因末端限制性片段长度多态性分析(T-RFLP)和实时荧光定量PCR技术,研究玉米不同生长时期土壤古菌群落组成和丰度的变化。结果表明,不同生长时期,根际土和非根际土古菌优势种群无显著变化,古菌群落组成无明显分离。乳熟期和完熟期古菌Shannon指数显著高于拔节期和抽雄期(P0.05),根际土抽雄期古菌Evenness指数显著低于其他生长时期(P0.05),非根际土不同生长时期Evenness指数差异不显著(P0.05)。土壤古菌16S rRNA基因丰度随生长时期的推进呈先升高后降低的趋势,乳熟期最高,拔节期最低,乳熟期显著高于拔节期和完熟期(P0.05),与抽雄期差异不显著(P0.05)。同一生长时期根际土和非根际土间无显著差异(P0.05)。     

Standardizing catch and effort data: a review of recent approaches

The primary indices of abundance for many of the world's most valuable species (e.g. tunas) and vulnerable species (e.g. sharks) are based on catch and effort data collected from commercial and recreational fishers. These indices can, however, be misleading because changes over time in catch rates can occur because of factors other than changes in abundance. Catch-effort standardization is used to attempt to remove the impact of these factors. This paper reviews the current state of the art in the methods for standardizing catch and effort data. It outlines the major estimation approaches being applied, the methods for dealing with zero observations, how to identify and select appropriate explanatory variables, and how standardized catch rate data can be used when conducting stock assessments.     

Bird species abundance–occupancy patterns and sensitivity to forest fragmentation: Implications for conservation in the Brazilian Atlantic forest

Developing a predictive theory for species responses to habitat fragmentation is a large, complex challenge in conservation biology, and meeting this challenge likely requires tailoring predictions to specific habitats and taxa. We evaluate the effects of fragmentation on forest birds living in three distinct forest ecosystems found in Brazilian Atlantic forest: seasonal semi-deciduous forest (SF), mixed rain forest (MF), and dense rain forest (DF). We test the hypotheses that (1) bird species most prevalent in SF (relative to other habitat types) will be least vulnerable to population declines in fragmented SF, and (2) species with stronger affiliations with DF or MF will be relatively more sensitive to fragmentation in SF. Using an exploratory statistical technique called “Rank Occupancy–Abundance Profiles (ROAPs),” we compared distribution and abundance of birds among large “continuous” areas of each forest type, then compared abundances in continuous SF forests with patterns of abundance in small fragments of SF, where edge effects could play a marked role in population dynamics. Overall, 39 species showed substantially lower local abundance, occupancy, or both in SF fragments versus continuous SF. As predicted, a higher proportion of bird species associated with DF appeared sensitive to fragmentation in SF; by contrast, species most abundant in SF and MF were similarly abundant in fragmented SF. Our study demonstrates how quantifying distribution and abundance in diverse habitats may enhance managers’ ability to incorporate species-specific responses to human disturbances in their conservation plans, and points out ways that even small reserves may have significant conservation value.     

Altitudinal terrestrial isopod diversity

We have assessed the diversity of terrestrial isopods across an elevational and habitat gradient on Mt. Panachaiko (NW Peloponnisos, Greece). Previous knowledge on the biodiversity of this mountain was restricted to very few records of individual species, and no systematic sampling had ever been applied for any animal taxon. We selected the most representative habitat types within an altitudinal range from 750 to 1700 m a.s.l., where we applied qualitative and quantitative monthly sampling using hand collecting and pitfall traps for 6 months during the snow-free period (June–November). We sampled three sites with maquis vegetation, one site with fir forest, one with sparse hawthorn vegetation and two at a highland meadow, and we compared the distribution and abundance patterns of isopod species among these habitat types. Overall, 13 isopod species were found, seven of which were also captured in pitfall traps. One species, Armadillidium lobocurvum, was extremely abundant at the most elevated sites, resulting in very uneven patterns of abundance. The habitat types with higher diversity of isopod species were the sparse hawthorns and the open maquis, and the richest month was July. We also discuss the phenology of the most abundant species at the highland meadows.     

Climate warming and the rainforest birds of the Australian Wet Tropics: Using abundance data as a sensitive predictor of change in total population size

Global average surface temperatures have increased rapidly over the last 100 years and there is accumulating evidence that climate change is already causing shifts in species’ distributions. We use extensive abundance data and expected range shifts across altitudinal gradients to predict changes in total population size of rainforest birds of Australian tropical rainforests in response to climate warming. According to our most conservative model scenario, 74% of rainforest birds of north-eastern Australia are predicted to become threatened (including 26 critically endangered species) as a result of projected mid-range warming expected within the next 100 years. Extinction risk varies according to where along the altitudinal gradient a species is currently most abundant. Upland birds are most affected and are likely to be immediately threatened by even small increases in temperature. In contrast, there is a capacity for the population size of lowland species to increase, at least in the short term. We conclude that abundance data collected across climatic gradients will be fundamental to gaining an understanding of population size change associated with climate warming.     

施肥对菜地土壤、蔬菜、径流中δ15N组成的影响

为了解施肥对蔬菜地土壤、蔬菜和地表水体中δ¹⁵N丰度的影响,选择2012至2018内施用不同肥料的28块蔬菜地（包括13块施用化肥蔬菜地、8块施用畜禽粪蔬菜地和7块施用商品有机肥加化肥蔬菜地）,采样分析表层土壤、蔬菜地上部分和地下部分及地表径流样的δ¹⁵N丰度。结果表明：施肥种类对土壤、蔬菜和地表径流中δ¹⁵N丰度均可产生显著影响,其丰度值由高至低依次为：畜禽肥>商品有机肥加化肥>化肥。蔬菜和地表水与土壤之间的δ¹⁵N丰度存在正相关。分析认为,蔬菜产品中氮同位素组成可以作为鉴定有机蔬菜的辅助依据,地表水体中δ¹⁵N丰度可作为水体中氮素污染源的指标。     

Cost-effective abundance estimation of rare animals: Testing performance of small-boat surveys for killer whales in British Columbia

Top predators are often rare, subject to anthropogenic mortality, and possess life-history traits that make them inherently vulnerable to extinction. IUCN criteria recognise populations as Critically Endangered when abundance is <250 mature individuals, but estimating abundance of rare species can be more challenging than for common ones. Cost-effective methods are needed to provide robust abundance estimates. In marine environments, small boats are more widely accessible than large ships for researchers conducting sightings surveys with limited funds, but studies are needed into efficacy of small-boat surveys. This study compares line transect and mark-recapture estimates from small-boat surveys in summer 2004 and 2005 for ‘northern resident’ killer whales in British Columbia to true population size, known from censuses conducted by Fisheries and Oceans Canada. The line transect estimate of 195 animals (95% CI 27-559) used model averaging to incorporate uncertainty in the detection function, while the mark-recapture estimate of 239 animals (CI 154-370) used a simple two-sample Chapman estimator. Both methods produced estimates close to the true population size, which numbered 219 animals in 2004 and 235 in 2006, but both suffered from the small sample sizes and violations of some model assumptions that will vex most pilot studies of rare species. Initial abundance estimates from relatively low-cost surveys can be thought of as hypotheses to be tested as new data are collected. For species of conservation concern, any cost-effective attempt to estimate absolute abundance will assist status assessments, as long as estimates are presented with appropriate caveats.     

Designing fecal pellet surveys for snowshoe hares

Index methods can be valuable for monitoring forest-dwelling vertebrates over broad spatial or temporal scales. Fecal pellet counts are often used as an index of density or habitat use of snowshoe hares, Lepus americanus, but previous surveys have used different plot types and sample sizes, leading to problems comparing results from different studies and questions about the inferential power of each study. In this paper, we use field data and simulations to examine how the precision, bias, and efficiency of four commonly used plot types vary with plot type, pellet density, and sample size. Although no one plot type was consistently superior, we recommend thin rectangles (5.08 cm × 305 cm (2 in. × 10 ft), 0.155 m²) or 1 m² circles over 0.155 m² circles or 10 cm × 10 m (1 m²) rectangles. We recommend that researchers explicitly address the power of their survey design to detect different pellet densities, because much larger sample sizes are needed at low pellet densities than at high pellet densities to obtain similar precision. Small sample sizes are also much more likely to be biased, which could lead to incorrect inferences about management of snowshoe hare populations. Both uncleared and cleared plots performed well and will have value in different research contexts.     

基于ASI法的滨海滩涂地水稻土壤有效氮、磷、钾丰缺指标

 【目的】为滨海滩涂地精准施肥提供理论依据。【方法】2005和2006年运用ASI法对位于黄海之滨的海丰农场进行土壤养分含量测定及水稻氮、磷、钾肥施用的推荐。选取60块肥力从高到低田块,利用不施肥、不施氮肥、不施磷肥、不施钾肥和施肥5个处理、3次重复的设计方案进行田间小区试验,按照相对产量＜50%时的土壤养分含量为“极低”、50%～75%为“低”、75%～95%为“中”、＞95%为“高”、再降为95%时为“过高”的标准建立土壤有效氮、磷、钾的丰缺指标体系。【结果】滨海滩涂水稻田土壤铵态氮的“极低”指标为＜2.5 mg N•L-1,“低”为2.5～11.0 mg N•L-1,“中”为11.0～19.5 mg N•L-1,“高”为19.5～34.0 mg N•L-1,“极高”为＞34.0 mg N•L-1;土壤有效磷的“极低”指标在海丰农场供试田块没有表现出来,“低”为＜13.0 mg P•L-1,“中”为13.0～28.5 mg P•L-1,“高”为28.5～60.0 mg P•L-1,“极高”为＞60.0 mg P•L-1;土壤有效钾的“极低”指标为＜35.0 mg K•L-1,“低”为35.0～95.0 mg K•L-1,“中”为95.0～175.0 mg K•L-1,“高”为175.0～335.0 mg K•L-1,“极高”为＞335.0 mg K•L-1。【结论】运用土壤养分状况系统分析法（ASI）和田间试验设计相结合是建立水稻土壤氮、磷、钾丰缺指标行之有效的方法。     

云南省小兽体表印鼠客蚤的丰富度及分布(摘要)(英文)

[目的]调查云南省印鼠客蚤的地域分布,并研究其是否与鼠疫分布一致。[方法]在云南省的22个县(市)进行现场抽样调查,采集小兽体表的印鼠客蚤并现场鉴定所获宿主,分析印鼠客蚤的地域分布、蚤指数、染蚤率。[结果]所捕获的60种小兽中,黄胸鼠的总染蚤率最高(13.04%),体表所采集的印鼠客蚤(1268)最多;褐家鼠有最高的蚤指数(0.83)。4个动物地理小区中,滇东高原小区的蚤指数(0.9)和染蚤率(21.73%)最高。[结论]印鼠客蚤主要分布在滇东高原小区,蚤指数、染蚤率和鼠疫发病率三者在云南省分布趋势相同。