Planning iterative investment for landscape restoration: Choice of biodiversity indicator makes a difference

Natural regrowth vegetation offers a cost-effective means of restoring some degraded landscapes. Worldwide, policy responses to climate change are increasing the attractiveness of investment in regrowth protection or facilitation which with strategic planning could also deliver substantial dividends for biodiversity conservation. This study compares the performance of two commonly used indicators of biodiversity conservation priority, irreplaceability and complementarity, as tools to support planning for iterative investment to protect natural regrowth of Brigalow, an endangered ecological community in subtropical eastern Australia. Brigalow covered more than seven million hectares prior to clearing, it now persists ‘intact’ on less than a tenth of that area but there are significant areas of regrowth.Data on Brigalow regrowth derived from mapping and remote sensing identify 10,555 patches covering 280,000 hectares in total. Two different classifications are used to represent Brigalow biodiversity: a land-type classification of 16 ‘regional ecosystems’ mapped at 1:100,000 scale, and a landscape-scale classification of 40 biogeographic subregions that discriminate relatively uniform landscapes at about 1:500,000 scale. Conservation targets are expressed as the extent of regrowth needed to increase the extent of intact or ‘remnant’ areas of each biodiversity feature to either 5% or 10% of its former extent. In each case, irreplaceability and complementarity are positively correlated, and either metric type could be used to identify relatively large sets of high-priority patches. However, regional-scale restoration is likely to involve iterative investment and therefore to require discrimination of relatively small sets of patches of the highest priority for biodiversity conservation. Irreplaceability is not an ideal measure of biodiversity value when planning such iterative processes, simply because irreplaceability is uninformative for ranking ‘high-value’ patches; they all have the highest possible score. This study demonstrates the importance of considering quite fundamental points when choosing metrics for conservation planning, such as the frequency distribution of values they produce. Where planning aims to identify quite small sets of very high value features metrics that are most variable among the highest value patches, like the one used for complementarity in this study, will be more useful than metrics that are strongly bounded at higher values.     

Effectiveness of a community-based intervention to improve nutrition in young children in Senegal: a difference in difference analysis

There are few studies of community growth promotion as a means of addressing malnutrition that are based on longitudinal analysis of large-scale programmes with adequate controls to construct a counterfactual. The current study uses a difference in difference comparison of cohorts to assess the impact on the proportion of underweight children who lived in villages receiving services provided by the Senegal Nutrition Enhancement Project between 2004 and 2006. The project, designed to extend nutrition and growth promotion intervention into rural areas through non-governmental organisation service providers, significantly lowered the risk of a child having a weight more than 2 sd below international norms. The odds ratio of being underweight for children in programme villages after introduction of the intervention was 0.83 (95% CI 0.686, 1.000), after controlling for regional trends and village and household characteristics. Most measured aspects of health care and health seeking behaviour improved in the treatment relative to the control.     

Variations of Bed Surface Sediment Size in a Channel Bend

Variations of sediment size and its gradation of the bed surface laver in a channel bend with nonuniform sediment are investigated experimentally. Four groups of sediment with the same initial median diameter (D _o ) but different initial size gradation (σ _o ) have been used for experiments which were run until the equilibrium bed topography was achieved. Analyses of experimental data have yielded the following results: (1) The time of equilibrium for bed evolution decreases asσ _o increases: (2) the median size of sediment (D) for a given section in the bend increases with increasing distance from the inner bank towards the outer bank, and it also increases with increasingσ _o ; (3) the value of D/D _o along the inner bank decreases with increasingσ _o , and it also shows a gradual decrease in the upper half of the bend and a slight recovery in the lower half, and (5) the transverse variation ofσ value exhibits a general trend increasing from the inner bank towards the outer bank.     

风化壳颗粒大小是决定典型干旱区硝态氮深部累积特征的关键因素

我国干旱区农田关键带过量施氮造成氮肥利用率低和土壤硝态氮大量累积,威胁生态环境安全。阐明干旱区土壤硝态氮累积特征及其影响因素,可为干旱区水肥综合管理提供科学参考。选择典型干旱区—新疆阿克苏地区为研究区域,从南向北沿地形序列布设三个钻孔点,分别为60年棉田XJ1（40°36′48.7″N,80°48′14.2″E）、32年老苹果园XJ2（41°16′16.2″N,80°19′9.1″E）和15年新苹果园XJ3（41°20′37.6″N,80°17′11.0″E）,海拔依次为971 m、1 129 m和1 213 m,采样深度依次为7.75 m、10.52 m和9.91 m,利用线性和非线性相关分析方法研究了土壤有关理化性质与土壤硝态氮浓度变异的关系。结果表明,海拔低处棉田和海拔高处不同种植年限的苹果园土壤深部均出现了硝态氮显著累积特征,深部浓度高达44 mg·kg-1,最大累积深度超过10 m。土壤含水量和不同粒径颗粒（砾石、砂粒、粉粒与黏粒）含量等关键理化性质可解释土壤硝态氮浓度垂直变异的约50%。其中,土壤含水量和土壤颗粒大小是决定土壤硝态氮深部累积特征的重要因素,土壤含水量越高、土壤颗粒越细,土壤硝态氮浓度通常越高。棉田土壤硝态氮在4 m深地下水位以下发生了明显的反硝化作用,使累积的硝态氮浓度降至较低水平（< 1 mg·kg-1）。苹果园因地下水位较深,土壤硝态氮未发生明显的反硝化作用,且已大量迁移累积至植物根系难以触及的深部区域（> 5 m）。土壤含水量是影响土壤硝态氮深部累积特征的地下部直接性因素;土壤颗粒大小通过调控土壤含水量空间变异,而成为影响土壤硝态氮深部累积特征的地下部根本性因素。     

激光粒度仪测量风成堆积物粒度的实验研究

中国北方第四纪风成堆积物的粒度是研究古气候与古环境的一个重要代用指标。粒度测量结果受到前处理方法的深刻影响。在黄土高原西部从北往南5个具有代表性的黄土剖面采集样品25块，对每个样品用不同的前处理方法处理后，用激光粒度仪进行测量。结果显示不同的前处理方法对黄土粒度测量结果会产生很大的影响。原始样品经过超声波振荡和加（NaPO3）6分散剂后，颗粒明显分散变细。在单独加入H2O2除去有机质和加入的HCl除去碳酸盐后，粒度也明显变细，而且南部的样品的差异比北部的要大。在黄土高原北部，石膏对粒度测量的影响较小。     

Impact of a Reduced Wheat Meal Sample Size on the Falling Number Test

The impact of a smaller sample of whole meal wheat (5.5 or 6.0 g) to replace the official 7.0 g used in the Falling Number test was investigated using samples of Canada Western Amber Durum (CWAD) and Canada Western Red Spring (CWRS) wheat. Use of either of the smaller sample sizes resulted in a significant shortening of the analysis time of the test. Reproducibility studies, using high and low falling number (FN) CWRS and CWAD samples, with three analyses per day over six days indicated no appreciable change in the coefficient of variation for the test using a smaller sample size. The maximum daily standard deviation of three replicates, 25.7 sec, was observed using the official 7.0‐g moisture‐corrected CWAD sample and was not significantly different from the 23.0 sec value obtained for a 5.5‐g sample of CWRS. The maximum average standard deviations observed over the six days of analysis were 13.7, 7.7, and 5.3 sec for the 5.5‐, 6.0‐, and 7.0‐g sample sizes, respectively, and were all associated with the sound, high FN, CWRS sample. While the use of 5.5 g allowed significant differentiation between high and low FN CWRS samples, the ability to discriminate high and low FN CWAD samples was lost at this sample size. FN analysis of CWRS (n = 144) and CWAD (n = 141) at 7.0 vs. 6.0 g, yielded correlation coefficients of 0.95 and 0.88, respectively. Regression analysis indicated a ±14.1 sec error associated with estimating a 7.0‐g FN value using 6.0 g of CWRS which increased to 26.4 sec for CWAD. Particle size analyses of whole meal after grinding indicated that the harder CWAD wheat fractured into a significantly greater percentage of larger particles than the corresponding CWRS. This difference may be a contributing factor to the greater variance associated with the CWAD 6.0‐g test and the inability to differentiate sound and slightly sprouted wheat at 5.5 g. Use of the 6.0‐g method, stopping the test after 200 sec, would also be applicable for screening purposes at commercial facilities where normal testing times (350–450 sec) could be reduced to meet designated quality requirements. This would offer a savings of 2.5 min/sample over the conventional method.     

植物氮素营养基因型差异研究进展

从形态学、生理生化、遗传学和分子生物学等方面综述了近年来国内外植物N素营养基因型差异的最新研究成果,并指出通过新品种选育提高植物N素利用效率切实可行。     

黄丘区小流域坝地沉积泥沙粒径剖面分布特征

坝地沉积泥沙记录了坝控小流域内土壤侵蚀特征及侵蚀环境演变的相关信息,是研究流域土壤侵蚀的重要媒介。研究通过在淤地坝内洪水冲开的一个11.66m的垂直剖面上按沉积旋回自下而上分层取样,分析沉积泥沙不同组分百分含量、特征粒径的剖面变化规律。结果表明:1)淤地坝内沉积泥沙主要以粗粉粒(0.01~0.05mm)为主,其平均含量为53.61%,且变异系数最小;2)个别层次出现粗砂(0.25~1mm),粗颗粒泥沙的出现对流域内大暴雨有一定的指示作用;3)沉积剖面的0~67cm为累积耕作层,该层的出现具有一定的时标意义;4)淤地坝沉积剖面存在粒径变异的转折点(600cm),该点可用来衡量水沙动力条件和沟道比降对泥沙粒径分布所起的作用。     

Size Guide Number and Rosin–Rammler Approaches to describe Particle Size Distribution of Granular Organic-based Fertilisers

The physical properties of organic-based fertilisers are not well known. The main objective of this study was to evaluate the range of granule size distributions of organic-based fertilisers and compare five approaches used to describe their size distribution: (1) the size guide number N_SG and uniformity index; (2) the size range variation coefficient; (3) the uniformity coefficient; (4) the geometric standard deviation of the particle size diameter; and (5) the Rosin–Rammler function. Six mineral (MF), four bulk-blended organic-based (BOF), and ten compound organic-based fertilisers (COF) were studied. Standard N_SG boxes and Tyler sieves were used to measure their granule size distribution. The size guide number ranged from 200 to 246 for MF, from 204 to 216 for BOF and from 99 to 255 for COF. The uniformity index was higher for slow release MF and for COF with N_SG>210. All five distribution parameters separated the fertilisers into similar groups. The coefficient of uniformity was the least discriminating approach in grouping the fertilisers, while the geometric standard deviation and size range variation provided similar results and the Rosin–Rammler approach was the most discriminating. The N_SG and uniformity index were estimated with the Rosin–Rammler function. Comparisons between estimated and measured size guide numbers indicated that the Rosin–Rammler function performs better for MF and for spherical granule shapes. Differences between the uniformity index values were greater for BOF, COF, and for cylindrical-shaped granules. The Rosin–Rammler function was not accurate for homogeneous and binomial particle size distributions, or for cylindrical granule shapes. However, in all other cases, this function was more precise and presented many advantages over the other methods, including the fact that it covers the entire range of particle sizes and can be used to estimate other parameters.     

激光粒度仪与沉降一吸管法测定褐土颗粒组成的比较

土壤颗粒组成是土壤的基本物理属性之一,沉降—吸管法是传统土壤颗粒分析的主要方法,激光粒度仪法是近年来新兴的粒度分析方法。为了研究二者的差异,选取了23个黏粒含量差异较大的褐土样品,采用上述两种方法对土样进行了分析。结果表明:激光粒度仪检测<0.002mm颗粒含量低于吸管法,但二者有较好的相关性,决定系数为0.97;在检测<0.02mm颗粒含量时两者比较接近,并且相关性很好,决定系数为0.99;检测<0.05mm颗粒含量时两者也比较接近,决定系数为0.91。激光粒度仪检测结果通过转换模型修正后,可以较好地反映褐土土壤颗粒组成情况。     

Sources of Variation in Oat Kernel Size

Oat kernel size uniformity is important to the oat milling industry because of the size fractionations that occur in the milling process. We measured frequency of single, double, and triple kernel spikelets and kernel mass of primary, secondary, and tertiary kernels from each spikelet type (for a total of six kernel types) to determine relative influence of kernel type, panicle position, genotype, and environment on oat kernel size for 10 oat cultivars grown at four locations. Kernel type was the most important factor affecting kernel size. Primary kernels from triple kernel spikelets were larger than primary kernels from double kernel spikelets. Tertiary kernels were the smallest. Environments that produced larger kernels also produced higher frequencies of triple kernel spikelets. Some genotypes produced no triple kernel spikelets in any environment, whereas others produced varying proportions, depending on the environment. Kernels closer to the top of the panicle were larger than those near the base. The presence of tertiary kernels was neither associated with lower groat percentages nor with increased proportions of undersized kernels. Most undersized kernels were kernel types other than tertiary.     

Limited-Information Modeling of Loggerhead Turtle Population Size

We attempt to estimate the size of a population of female loggerhead turtles. In traditional capture-recapture experiments to estimate the size of an animal population, individual animals are tagged and the information about which individuals are captured repeatedly is crucial. For these loggerhead turtle data, information about individual turtles is not available. Rather, we observe only the counts of successful and failed nestings at a location over a series of days (in our case, three). We view the turtles’ nesting behavior as an alternating renewal process, model it using parametric distributions, and then derive probability distributions that describe the behavior of the turtles during the three days via a 3-way contingency table. We adopt a Bayesian approach, formulating our model in terms of parameters about which strong prior information is available. We use a Gibbs sampling algorithm to sample from the posterior distribution of our random quantities, the most crucial of which is the number of turtles remaining offshore during the entire sampling period. We illustrate the method using data sets from loggerhead turtle sites along the South Carolina coast. We provide a simulation study which illustrates the quality and robustness of the method and investigates sensitivity to prior parameter specification.     

Conservation value of the herbaceous vegetation in hedgerows - does organic farming make a difference?

The aim was to compare and test differences in the conservation value of hedge bottom vegetation on organic and conventional farms. The studied hedgerows (28 organic and 28 conventional) were on average 14 years old and established in the same way, except that organic hedgerows were established and managed without use of pesticides. We investigated three sample plots of 10 m² in all hedgerows together with a set of 13 explanatory variables. There were no differences in soil texture between hedgerow types but organic farms had higher pH and lower conductivity. Organic farms had higher total N values, which are explained by a slightly higher content of organic matter. There was highly significant interaction between farming type and neighbouring crop type according to soil phosphate concentration. Significantly more plant species were found in the organic hedgerows. The species compositions in organic hedgerows appeared significantly more similar to semi-natural communities when compared with other plant communities. We conclude that organic farming is slightly superior with regard to conservation of herbaceous diversity of hedgerows in intensively cultivated agricultural landscapes. The possible reasons for this are discussed.     

Dry-heating makes hen egg white lysozyme an efficient foaming agent and enables its bulk aggregation

Dry-heating is considered to be one of the most promising approaches to improving the functionality of food proteins. It has been shown that even if only minor structural modifications occur during dry-heating, the foaming properties of proteins are highly improved. With the recent results obtained in the field of foam stabilization by nanoparticles or protein aggregates in mind, a study was undertaken on the impact of dry-heating of lysozyme, used as a model protein, on its foaming properties. This work highlighted the fact that dry-heated hen egg white lysozyme simultaneously exhibited enhanced foaming properties and aggregation capacity. Although the conditions that favored bulk aggregation (high ionic strength, pH, treatment duration, and protein concentration) also favored foaming properties, the large bulk aggregates were not essential to obtain the best functionality. It is envisaged that heat-treated lysozyme may self-associate at the air/water interface, stabilizing air bubbles.     

Particle Number Size Distribution and Weight Concentration of Background Urban Aerosol in a Po Valley Site

Measurements of particle size distributions and PM_2.5 from an urban background site in the Central Po Valley are analysed; the site is one of the medium–small-size cities in the central valley, without the direct influence of the metropolitan and industrial area of Milan and of the Adriatic Sea. The data comprise number concentration of particle with diameters ranging between 10 and 700 nm, PM_2.5 and main meteorological variables from February to August 2008. Daily cycles of the observed pollutants are analysed, along with auto-correlation function for particle number concentration and principal component analysis (PCA) of all the available variables; finally, the diurnal pattern of PM_2.5 low-, medium- and high-pollution events has been investigated. Total particle number concentration showed a daily pattern both in winter and summer, although different between weekdays and Sundays and with wider variations during the cold season. A daily cycle is present for the geometric mean diameter of nucleation mode particles in winter and of nucleation and Aitken mode particles in summer. PM_2.5 showed a slight daily pattern for weekdays and Sundays, similar, but lagged, to total particle count cycle. Mixing layer depth resulted the main process controlling PM_2.5, although also human activities contribute to PM_2.5 concentration and allow some deposition and (re-)mobilisation at the first hours of the day and morning rush hour, respectively, while particle number concentration responds immediately to anthropogenic sources. PCA confirmed the dependence of particle number concentration also on meteorological variables, e.g. mixing layer height, wind speed or atmospheric pressure, showing the important influence of regional meteorology on local pollution conditions. Modena can be considered a representative test area of the effect of the meteorological regime for the Central Po Valley on atmospheric particle concentration patterns, characterised by steady high-background concentration.     

噶顺戈壁地表砾石粒度特征分析

对戈壁表面砾石粒径的研究,可帮助了解戈壁特征,分析戈壁造成自然灾害的原因,认识沙粒迁移、沙漠扩展以及指导防沙工程.本研究结合野外调查,分析噶顺戈壁洪积扇21个样点砾石的粒度组成、平均粒径、分选系数、偏度和峰度等粒度特征.结果表明:1)受洪水、重力与风蚀等作用的影响,戈壁地表砾石均以中砾为主(66.35％～95.04％).海拔最高处以石质为主(85.54％),平均粒径φ值为-9.09 (545.2 mm).砾石质量分数呈现出随海拔增加,中砾质量分数降低,而粗砾质量分数升高的趋势.2)粒度特征为:平均粒径φ值变化范围为-9.09(545.2mm)～-6.15 (153.9 mm);除样点12为分选中等外,其余样点的均处于分选较好以上水平(0.28 ～0.53);偏度以负偏为主导(80.95％),地表以细砾和中砾等细粒径砾石为主;峰度中,宽平和很宽平占整体的57.14％,中等占23.81％,尖窄和极尖窄占19.05％,显示砾石分布相对较均匀,在不同位置的砾石,具有微弱的地表过程差异性.3)分选系数与平均粒径之间,无明显的相关关系;而偏度与平均粒径间,存在正相关关系.研究结果对物源的岩性及戈壁发育环境具有重要的指示意义.     

旋耕碎土质量的分形描述

建立了旋耕土壤块体大小分布的分形方程,导出了土块分布均值和方差表达式,并用已有的旋耕试验结果验证了方程的正确性。利用该方法分析了前进速度、刀轴回转速度及斜置角对斜置式旋耕的碎土程度的影响。     

中国土壤微生物量的大小

The microbial biomass C, N and P of soils all over China were determined in this study to study their affecting factors. The results, about 100-417 mg C kg^-1 soil, 18-51 mg N kg^-1 soil and 4.4-27.3 mg P kg^-1 soil, showed the biomass C, N and P in linear relationship with the soil total organic C, toal N and soil organic P. The ratios of C: N and C:P, ranging from 5.6 to 9.6 and from 11.2 to 48.4 respectively, were affected by soil pH, texture, crop rotation, macroclimate, etc. The ratio of C:N in soil biomass increases gradually from the north to the south in China.     

Size of Microbial Biomass in Soils of China

The microbial biomass C,N and P of soils all over China were determined in this study to study their affecting factors.The results,about 100-417 mg C kg^-1 soil,18-51 mg Nkg^-1 soil and 4.4-27.3mg P kg^-1 soil,showed the biomass C,N and P in linear relationship with the soil total organic C,toal N and soil organic P.The ratios of C:Nand C:P,ranging from 5.6 to 9.6 and from 11.2 to 48.4 respectively,were affected by soil pH.texture,crop rotation,macroclimate etc.The ratio of C:N in soil biomass increases gradually from the north to the south in China.