Structural response of black locust (Robinia pseudoacacia L.) and small-leaved lime (Tilia cordata Mill.) to varying urban environments analyzed by terrestrial laser scanning: Implications for ecological functions and services

Quantitative measurements of structure and morphology of urban trees are hardly exhausted so far, especially in regard to variations caused by altering urban environments. However, structure and functions of trees are heavily interwoven. In fact, knowledge about structural attributes is essential for a better understanding of urban ecosystem functions and services. In order to scrutinize spatially explicit and detailed structural attributes under varying urban environments, we acquired terrestrial laser scans and applied the according methodological approaches to the common urban tree species black locust (Robinia pseudoacacia L.) and small-leaved lime (Tilia cordata Mill.). We analyzed 52 small-leaved limes and 41 black locust trees within the city of Munich (Germany). Species as well as growing location had a significant effect on the height-diameter relation. We also found greater crown volumes for small-leaved lime. Black locust however, displayed more crown projection area and likely more shade efficient crown shapes at similar volumes. Stem inclination of black locust was found to be higher in parks than in street canyons with town squares lying in between. Furthermore, black locust displayed strong crown asymmetry in park areas, likely caused by competition with neighbors. The angles of main branches did not differ significantly between both species nor between the growing location. Branch angles, branch bending, the length of the branches as well as species and growing location had a significant effect on vertical crown center position, i.e. general crown shape. Surface complexity of lime is lower than of black locust, with its lowest manifestation in parks. Fractal-like crown surface structures, increasing surface roughness and complexity, were found to be more pronounced for black locust than for small-leaved lime. Thereby, black locust featured the highest crown surface complexity in parks, the lowest in street canyons. The results suggest that studies on spatially explicit tree structures may contribute to more target oriented tree plantings and thus, more effective exploitation of ecosystem services and benefits.     

天然青杨种群性成熟条件及性别间差异

对小五台山地区青杨种群进行野外调查和数据分析研究,发现雌雄植株的性成熟条件具有差异。雌株性成熟的最小年龄(17 a)小于雄株(21 a),而雄株性成熟时的最小胸径和株高都大于雌株,不同性别的青杨其性成熟条件存在差异,雌株性成熟时间一般早于雄株,并且其成熟时的个体也小于雄株。     

不同生境大托叶猪屎豆构件生物量分配的权衡特征

为探讨生境对大托叶猪屎豆（Crotalaria spectabilis）构件生物量分配及其权衡关系的影响,本研究选择林下和裸地2种生境,通过野外调查取样和室内分析,研究了大托叶猪屎豆构件生物量分配特征、异速生长关系及其在生境间的差异性和权衡特征。结果表明,裸地生境大托叶猪屎豆各器官干重、全株干重及繁殖分配比例均显著高于林下,但其根冠比和茎生物量比则显著低于林下。林下生境构件生物量之间多为异速生长关系,而裸地生境多为等速生长关系,但2种生境下繁殖分配速率均显著高于其他构件。繁殖分配比例随个体增大显著增加,而茎与叶生物量分配则显著降低,呈现相反的个体大小依赖性。可见,大托叶猪屎豆在面对变化环境时不同器官间具有显著的资源分配调整与权衡。     

皖南花猪消化系统生长发育研究

利用皖南花猪纯种仔猪６４头,按１,３０,４５,６０,９０,１２０,１８０,２４０,３００和３６０日龄段分别屠宰测定其胃重,;胃底腺重,肝重,小肠和大肠的重,长度和单位长度重量以分析皖南花猪消化系统的生长发育规律。供试猪６０日龄断奶,断奶后生长肥充猪供试日粮前期ＣＰ＝１７．５％,ＤＥ＝２８００ｋｃａｌ／ｋｇ;后期ＣＰ＝１５．０％,ＤＥ＝２７００ｋｃａｌ／ｋｇ;日粮粗纤维６．０％,建立了猪消化系统累积     

白刺叶片解剖结构性状异速生长与生态适应性研究

本实验以不同生境下3种白刺(西伯利亚白刺、大果白刺、唐古特白刺)叶片为研究对象,测量3种白刺的叶片解剖结构中叶片厚度、上角质层厚度、上表皮厚度、栅栏组织厚度、海绵组织厚度、下表皮厚度和下角质层厚度等性状指标,用经典异速方程(Y=βX^α)描述叶片解剖性状之间的关系。结果表明：不同生境的白刺叶片解剖性状均有显著性差异(P＜0.05),均呈显著性幂指数异速生长关系,其异速系数表现显著性差异(P＜0.05),其异速指数表现出两类完全不同的规律,一类是≈1,另一类是＜1,存在着资源分配的权衡。不同生境白刺叶片解剖性状的变异系数在0.10～0.45之间,属于相对稳定的系统演替性状。植物生境中的海拔高度、年降水量与年蒸发量是影响叶片性状的主要因素,3种白刺通过长期的外界异质性的环境因子驱动改变叶片结构性状,可以使其在不同的生境下朝着最适的异速生长曲线进化。     

Growth of <Emphasis Type="Italic">Dactylis glomerata</Emphasis> along a light gradient in the central Appalachian region of the eastern USA: I. Dry matter production and partitioning

Microsite influences on resource allocation related to silvopastoral swards undergoing repeated defoliation are unclear. Defoliating traditional pasture species according to canopy development criteria may not be appropriate when the plants grow as understory crops in woodlots. An experiment using container-grown plants was conducted under field conditions to determine how open (O), shaded woodland (W) and open-to-shaded woodland transition zones (E _O, E _W), representing the partial shade conditions found in silvopastoral settings, influenced productivity and dry matter allocation in Dactylis glomerata L. Plants established in spring (SP) and late summer (LS) were clipped each time mean sward height reached 20 cm. Dry matter production differed for SP and LS plantings, and was greater in O than W sites. Dry matter allocation to shoots of SP plants indicated some agronomic benefit associated with the E _O and E _W sites. Leaf mass did not vary with irradiance, but stembase mass did. The SP plants had numerous small tillers whereas LS plants were composed of comparatively fewer but more massive tillers. Plants growing at O, E _O and E _W were similar, whereas plants in the W site were smaller and had the fewest tillers regardless of planting time. Results suggest that defoliation management for shaded components of silvopastoral systems should be based on some index other than sward height, and that management criteria might change during the growing season. Less intensive removal (e.g., 10-cm rather that 5-cm residue) should be considered for defoliated, shade grown plants, since this could allow more stembase and nonstructural carbohydrate storage tissues to remain. The US Government’s right to retain a royalty-free, non-exclusive copyright is achnowledged.     

Maternal size dependency of ovariole number in Dastarcus helophoroides (Coleoptera: Colydiidae)

To evaluate the relationship between reproductive potential and body size of Dastarcus helophoroides Faimaire (synonym Dastarcus longulus Sharp), 17 adult females obtained under outdoor conditions were dissected individually to count the ovarioles and determine the mean size of mature eggs in ovarioles and oviducts following the measurements of fresh body weight, body length, maximum body width, maximum width of prothorax, and elytral length. Each female had two ovaries. The number of ovarioles per female varied from 36 to 154 depending on maternal body length. However, the mean length and width of mature eggs were independent of body length. There were no differences in any body-size traits and allometry between the sexes.     

Use of Body Surface Area to Calculate Chemotherapeutic Drug Dose in Dogs: II. Limitations Imposed by Pharmacokinetic Factors

Anticancer drug dosages that specify the maximum dose and minimum dosing interval that are tolerated in a population of dogs are commonly recommended. Because the differences between the effective and toxic doses of most cancer chemotherapeutics is slight, it is important to achieve therapeutic concentrations in tumor tissues at the same time that concentrations in nontarget tissues are minimized. In order to determine the dosage regimen that will most likely accomplish these goals, similar drug concentrations must be achieved in all patients dosed according to a specific regimen. Dosing based on body surface area (BSA) is generally used in an effort to normalize drug concentrations. This is because it is well recognized that measures of many physiologic parameters that are responsible for drug disposition, including renal function and energy expenditure, can be normalized by use of BSA. However, there is substantial evidence that drug disposition is not always proportional to BSA. Differences in distribution, metabolism, and excretion pathways may preclude dose extrapolation among species or among individuals within a species based on BSA. Moreover, genetic differences in drug metabolism are well recognized in humans and in laboratory animals, and it is likely that similar differences exist among breeds of dogs. A review of the pharmacokinetic disposition of several cancer chemotherapeutics suggests that studies are needed to determine the most effective method to achieve equivalent anticancer drug concentrations in diverse veterinary patients.     

The influence of rapid growth in broilers on florfenicol pharmacokinetics – allometric modelling of the pharmacokinetic and haemodynamic parameters

1. The aim of this study was to determine if the pharmacokinetics (PK) of florfenicol (FF) undergo age-dependent changes in broilers. Since drug elimination depends on cardiovascular functions, a haemodynamic study was performed in parallel.

2. Broilers of 0.68, 1.27, 2.45 and 5.13 kg were administered FF in a single intravenous dose of 30 mg/kg body weight. Plasma drug concentrations were determined using high-performance liquid chromatography and PK parameters were calculated using a non-compartmental model. Echocardiography was used to measure haemodynamic functions.

3. During growth, the area under the drug concentration-time curve (AUC_inf) increased from 25.7 ± 2.9 to 39.0 ± 8.0 mg h/l. Total body clearance (Cl_B) gradually decreased from 1.19 ± 0.14 to 0.80 ± 0.15 l/h/kg. Elimination half-life increased from 0.73 ± 0.08 to 1.07 ± 0.07 h, whereas volume of distribution (V_ss) remained unchanged. Haemodynamic measurements revealed an increase in cardiac output, from 495 ± 65 to 1303 ± 306 ml/min, in the respective body weight groups.

4. Allometric models for PK and haemodynamic parameters were developed and validated. All models proved to be statistically significant; however, only models for Cl_B and V_ss met stringent validation criteria. Model for Cl_B was used to calculate an optimal dose for a given age group that provides uniform AUC_inf.

5. Age-dependent change in FF kinetics may cause variability in therapeutic response under clinical conditions. A novel approach to the dosing protocol was proposed as a means of optimising therapeutic efficacy.     

Selective logging alters allometric relationships of five tropical tree species in seasonal semi-deciduous forests

In selectively logged forests,trees are more likely to expand their diameters(D)at the expense of height(H)growth,resulting in variations in H:D relationships.This study examines how selective logging affects the H:D allometric relationships of five common tree species and whether the effects vary with functional groups(shade-intolerant or shade tolerant)in seasonal semi-deciduous forests.Individuals of five species in a 3000 m^2(0.3 ha)plot were marked and heights and diameters recorded.Most of the species,with one exception,showed greater investment in diameter per increment of height compared to an unlogged forest,possibly because of the greater light available.This study shows the effects of selective logging on species populations as evidenced by increases in H:D ratios.Comparison of forest fragments with different degrees of human impact is important because it allows us to understand the differences in architectural characteristics caused by selective logging.