Fertilizer and planting strategies to increase biomass and improve root morphology in the natural rubber producer Taraxacum brevicorniculatum

Taraxacum brevicorniculatum produces high-quality natural rubber in its roots and could be developed as an alternative commercial source of this valuable raw material. However, current wild type accessions have a low biomass and branched roots that make them difficult to harvest. We set out to determine the optimum fertilizer and spacing requirements for T. brevicorniculatum plants in greenhouse and field trials, aiming to increase root biomass and reduce branching thus maximizing rubber yield and reducing losses during harvesting. Our preliminary data from greenhouse trials show that fertilizers containing calcium and magnesium in addition to NPK (nitrogen, phosphorus and potassium) increase root biomass by 25% compared to standard NPK fertilizer plus boron, and by 15% compared to NPK plus calcium. Fertilizers with a low N:P ratio increased the root biomass in greenhouse and field trials. Dense sowing (5-10 cm between plants) inhibits root branching and leads to the formation of single taproots that can be harvested easily. We therefore provisionally recommend the application of low N:P ratio NPK fertilizer supplemented with calcium and magnesium to closely-spaced plants in order to achieve the greatest increase in plant biomass per hectare.     

Quantitative disease resistance assessment by real-time PCR using the Stagonospora nodorum-wheat pathosystem as a model

Measuring disease resistance accurately and reproducibly is a key requirement for the introgression of partial resistance genes into breeding lines. Here, a qPCR protocol is used to measure fungal biomass, using the wheat- Stagonospora nodorum pathosystem as a model. Seven cultivars of differing reported resistance levels were used. Fungal biomass taken at 220°C thermal days after inoculation accurately predicts the final grain weight loss. It is concluded that a test based on qPCR methods is specific, quantitative, rapid and objective. Such tests could provide useful and economic tools in the development of robustly resistant crop cultivars.     

Crop diversity in homegardens of southwest Uganda and its importance for rural livelihoods

Homegardens are traditional food systems that have been adapted over generations to fit local cultural and ecological conditions. They provide a year-round diversity of nutritious foods for smallholder farming communities in many regions of the tropics and subtropics. In southwestern Uganda, homegardens are the primary source of food, providing a diverse diet for rural marginalized poor. However, national agricultural development plans as well as economic and social pressures threaten the functioning of these homegardens. The implications of these threats are difficult to evaluate, because the structure and functions of the homegardens are not well understood. The aim of the study was to identify patterns and influencing factors in the diversity of homegardens by documenting the floristic diversity and its interactions with spatial, environmental and socio-economic factors. A geographically and socially focused assessment of floristic diversity in 102 randomly selected homegardens in three districts of southwest Uganda was conducted along a deforestation gradient following a human ecology conceptual framework and testing multiple quantitative hypotheses regarding the above mentioned factors. A merged mixed-method approach was followed to provide context and feedback regarding quantitative findings. Results show a high total richness of 209 (mean 26.8 per homegarden) crop species (excluding weeds and ornamentals) dominated by food species, which constituted 96 percent of individuals and 44 percent of all species. Forest-edge homegardens maintained higher plant diversity compared to homegardens in deforested areas and near degraded wetlands. Multiple linear regression models indicated elevation, location, homegarden size, distance to market, additional land ownership (outside the homegarden) and livestock ownership as significant predictors of crop diversity. Cluster analysis of species densities revealed four garden types: ‘diverse tree gardens’, ‘small forest-edge gardens’, ‘large, old, species-rich gardens’, and ‘large, annual-dominated herb gardens’, with 98% correct classification. Location, elevation, and garden size were also important determinants in the cluster assignment. We conclude that the diversity of the studied homegardens may be changing as part of adaptive traditional practices and in response to external drivers. The identified patterns illustrate the importance of homegardens for rural livelihoods and may offer some ways to support farmers to maintain these systems as relevant mechanisms for development in Uganda.     

A comparison of anesthetic complications between diabetic and nondiabetic dogs undergoing phacoemulsification cataract surgery: a retrospective study

Objective To compare the incidence of anesthetic complications in diabetic and nondiabetic dogs undergoing general anesthesia and phacoemulsification cataract surgery. Procedure The medical and anesthetic records of all dogs undergoing phacoemulsification cataract surgery at Davies Veterinary Specialists between 2005 and 2008 were reviewed. Anesthetic records were evaluated by an ECVAA Diplomate. Dogs for which records were incomplete were excluded. The anesthetic technique, including all drugs administered in the perioperative period, was recorded. The anesthetic complications investigated included hypotension (MAP (mmHg): ≥55 none/mild; ≤54 moderate/severe), bradycardia (<60 bpm associated with hypotension) and hypothermia (esophageal temperature <36.7 °C). Where hypotension was present, the method of and response to treatment was recorded. The incidence of severe hyperglycemia (blood glucose >13.75 mmol/L (250 mg/dL)) in the diabetic group was also assessed. Results 66 diabetic and 64 nondiabetic dogs were included in the study. Diabetic dogs were more likely to develop moderate and severe intraoperative hypotension than nondiabetic dogs. Forty‐four percent of diabetic dogs had at least one episode of severe hyperglycemia whilst anesthetized. Conclusions Diabetic dogs undergoing phacoemulsification are more likely to suffer the anesthetic complications of moderate and severe hypotension than nondiabetic dogs. The increased incidence and severity of hypotension in diabetic dogs may be explained by hypovolemia secondary to hyperglycemia and resultant osmotic diuresis.     

Calibrating the liana crown occupancy index in Amazonian forests

Lianas hold an important, but understudied, role in forest dynamics, however they are difficult to measure and detailed liana measurements are time consuming. Many researchers have therefore used an ordinal scale index, the crown occupancy index (COI), to describe the liana load carried by trees. Here we assess the overall effectiveness, in terms of accuracy, precision, repeatability and efficiency, of the COI in tropical forests. We relate the COI to more detailed liana measurements at the individual tree-level and site-level, comparing sites with different levels of liana infestation. Our results show (1) that the COI accurately measures individual tree and plot level liana loads, indicated by the strong correlations between the COI and the number and basal area of lianas. However, (2) as expected, the COI is only weakly related to the basal area of lianas rooted close to the tree, which is a proxy for competition for below-ground resources. The COI is also (3) an efficient measure of liana loads, as the input time needed for a COI survey is considerably less than that of a detailed liana survey. We also (4) found a high degree of repeatability in COI classification between observers. Additionally (5), the COI can be used to differentiate between sites in terms of their overall liana canopy competition (precision), but (6) may not be a precise indicator of the site-level mean basal area of lianas in tree crowns.     

Drivers of bryophyte diversity allow implications for forest management with a focus on climate change

Understanding the major drivers of diversity in forests is crucial for ecologists, conservationists, and particularly forest managers. In most forested habitats, bryophytes are diverse and important primary producers. Here we report the first study of the relative importance of regional macroclimate as compared to local variables on abundance, species richness, and community composition of bryophytes growing in soil and in dead wood in a mountain temperate forest. Using PCA axes, we built predictor sets for macroclimate, microclimate, soil attributes, and dead wood availability. The explanatory power of each set was tested using variance partitioning. Abundance and species richness of soil bryophytes was best explained by microclimate, whereas the community composition did not distinctively differ between the environmental sets. In contrast, dead wood bryophyte abundance, species richness, and community composition was clearly driven by macroclimate. Among the single axes, the component represented best by soil moisture was the main driver for soil bryophyte abundance. In contrast, dead wood bryophyte abundance was mostly affected by components correlated with minimum global radiation and minimum temperatures as well as by the component represented by dead wood. The component represented by canopy openness was superior in explaining the community composition of both soil and dead wood bryophytes. We conclude that (1) dead wood amounts should be increased in closed stands to act as a buffer during climate changes, and (2) open canopy, which provides important habitats for soil-inhabiting bryophytes, should be provided by management with slow reforestation after natural or logging openings.     

Feed intake,growth and nutrient retention of common sole (Solea solea L.) fed natural prey and an artificial feed

This study compares growth, intake and retention efficiencies of nutrients and energy between common sole (Solea solea L.) fed ragworm (Nereis virens, Sars), blue mussel (Mytilus edulis L.) and an artificial (commercial) feed. Food types were fed to common sole (mean initial body weight: 44.9 ± 2.3 g) in excess three times a day over a 54‐day‐period. The growth rate in common sole fed the natural prey (8.5 g kg^?0.8 d^?1) was significantly higher compared to the growth rate in fish fed the artificial feed (5.1 g kg^?0.8 d^?1). Nutrient and energy intake was significantly lower in common sole fed the artificial feed than in fish fed natural prey. The only exception was fat intake which was higher in common sole fed the artificial feed in contrast to fish fed the natural prey. Nutrient and energy retention efficiencies were significantly lower in common sole fed the artificial feed than in fish fed the natural prey. In conclusion, the low growth in common sole fed the artificial feed was related to lower nutrient and energy intake as well as lower nutrient and energy retention efficiencies. It is suggested that reduced intake of the artificial feed might be related to the high dietary fat content of the artificial feed.     

Analysis on pedodiversity and spatial subset representativity—the German soil map 1:1,000,000

Knowledge about spatial soil variation in terms of measured pedodiversity, as well as the spatial distribution of soils in terms of spatial subset representativity, offers the possibility to estimate the quality and variance within a soil map. Additionally, it can help to identify representative sample locations. Demonstrated at the German soil map at a scale of 1:1,000,000, this study describes a methodology to analyze the distribution of taxonomical pedodiversity using the Simpson index and a new approach to derive representative spatial subsets based on a modified χ²‐test (χ_m²), which can be used as monitoring areas. To analyze the spatial composition of the soil map and to detect differences in the underlying mapping schemes of the German soil map 1:1,000,000, three different spatial data structures were studied: (1) the entire soil map, (2) the soil map segmented into geomorphological regions, and (3) the soil map segmented into the Federal States of Germany. Representative patches of varying sizes were statistically derived for all spatial subsets as well as the entire soil map ranging from 20 km × 20 km up to 70 km × 70 km. The results show that the measured pedodiversity is linked to both the geomorphology as well as the political borders of the Federal States. On the one hand, this reveals the uncertainty of measuring pedodiversity on the basis of soil‐class maps as the spatial representation of pedodiversity is influenced by the different mapping traditions and methods applied in the 16 Federal States of Germany. On the other hand, it allows the analysis of the aggregation schemes of different landscapes. The presented approach helps to understand large soilscapes and to compare different soil maps of different states and countries as well as to enhance the soil map with additional information. Furthermore, the representative patches can be used to select soil‐monitoring areas.     

基于ERS-1/2和Envisat ASAR数据的大区域森林制图研究

分别利用1995—2000年的ERS-1/2串行数据和2005年的Envisat ASAR数据对我国东北林区进行森林制图研究。针对ERS-1/2数据相干模型,采用一种不依靠地面实况数据而是基于MODIS植被连续覆盖产品进行训练的方法,从而实现进行大区域森林蓄积量分级制图的目的。分级制图包括0～20、20～50、50～80和80 m3/hm2 4个蓄积量等级。基于Envisat ASAR数据,采用面向对象的分类方法,进行自动化森林和非森林分类处理。基于2005年Landsat TM-5分类结果的交叉验证表明:这2种传感器SAR数据均可用于大区域森林制图。2期森林制图结果为进一步的森林变化分析以及制图更新研究提供支持。