Long-term adaptation potential of Central European mountain forests to climate change: a GIS-assisted sensitivity assessment

An ecological risk assessment is described for determining the adaptation potential of the approximately 11 000 Swiss Forest Inventory points (FIP) to a hypothetically changing climate. The core of the study is a spatially explicit forest community model that generates estimates of the potential natural vegetation for the entire potential forest area of Switzerland under today's as well as under altered climate regimes. The model is based on the Bayes formula. The probabilities of the communities occurring along ecological gradients are derived from empirical data featuring the relationships between quasi-natural vegetation types and measured site variables. Bioclimatological input variables are the quotient between July temperature and annual precipitation (model version A) or mean annual temperature (model version B). Other site variables include aspect, acidity of top soil and, to account for continentality, geographical region. Climate change scenarios are defined as follows: ‘Moderate climate change’ implies an increase of the mean annual temperature of 4°C to 1.4°C depending on the region (model version B) or an increase of the July temperature of 1.5°C (model version A). ‘Strong climate change’ implies an increase of the mean annual temperature of 2°C to 2.8°C (model version B) or an increase of the July temperature of 3.0°C (model version A).

The simulation experiment showed that the geographical distribution of 15 potential natural forest types (distinguished on the basis of floristic affinities) varies considerably with changing temperature. Under moderate warming 30–55% of the FIP change their potential natural vegetation type, whereas under strong climate change the values increase to 55–89% depending on the model version used. In the ecological risk assessment the existing tree species composition on any FIP was compared with the expected tree species composition under today's as well as under altered climate regimes. A major finding indicated that, under the current climate conditions, approximately 25–30% (depending on the model version used) of all FIP must be considered as poorly adapted, i.e. less than 20% of the actual basal area consists of tree species that are expected as dominating taxa. This definition applies for trees with a diameter at breast height (DBH) ≥ 12 cm. Moderate warming increases the percentage of poorly adapted FIP by 5–10% (relative to all FIP considered), strong warming leads to a 10–30% increase of poorly adapted FIP (relative to all FIP considered). If trees with a DBH < 12cm are considered, the percentage of FIP that have to be classified as poorly adapted is reduced significantly. There are strong regional differences as exhibited in risk maps of 10 km × 10 km resolution.     

胡杨抗盐机理初探

对两年生胡杨（Ｐ．ｅｕｐｈｒａｔｉｃａＯｌｉｖｅ）和胡杨的杂种（密叶杨（Ｐ．ｔａｌａｓｉｃａＫｏｍ）×（胡杨＋白柳（ＳａｌｉｘａｌｂａＬ））实生苗进行５０ｍＭ和２００ｍＭ氯化钠（ＮａＣｌ）溶液的盐胁迫试验。得出胡杨的四种耐盐机制：（１）减少叶片的数量和面积；（２）叶柄肉质化（叶面积随盐胁迫的增加而减少）；（３）茎和叶片的斥盐性（高盐处理时，胡杨叶片中Ｎａ＋和Ｃｌ＋的含量只有胡杨杂种的三分之一）；（４）选择吸收Ｋ＋和Ｃａ２＋以抵抗盐离子的毒性，并保持膜的完整性（胡杨茎中Ｃａ２＋的含量随着盐处理浓度的增加而增加，叶片中Ｋ＋的含量却保持不变）。     

Substrate-controlled succession of marine bacterioplankton populations induced by a phytoplankton bloom

Phytoplankton blooms characterize temperate ocean margin zones in spring. We investigated the bacterioplankton response to a diatom bloom in the North Sea and observed a dynamic succession of populations at genus-level resolution. Taxonomically distinct expressions of carbohydrate-active enzymes (transporters; in particular, TonB-dependent transporters) and phosphate acquisition strategies were found, indicating that distinct populations of Bacteroidetes, Gammaproteobacteria, and Alphaproteobacteria are specialized for successive decomposition of algal-derived organic matter. Our results suggest that algal substrate availability provided a series of ecological niches in which specialized populations could bloom. This reveals how planktonic species, despite their seemingly homogeneous habitat, can evade extinction by direct competition.     

Study of nebulization delivery of aerosolized fluorescent microspheres to the avian respiratory tract

This study investigated the delivery of an aerosol of monodisperse microspheres to the respiratory tract of birds following aerosol exposure. Adult domestic pigeons (Columbia livia domestica, n = 5 birds per timed treatment) were exposed to an aerosol of fluorescent 1.0 microm diameter carboxylate microspheres for 0.5, 1, 2, or 4 hr. During the aerosolization period, the birds were free-standing in a plexiglass treatment chamber and the aerosol was delivered using a commercial nebulizer. Immediately following aerosol exposure, the birds were euthanatized and the carcasses were intravenously infused with a modified paraformaldehyde/gluteraldehyde fixative. Evaluation of microsphere distribution was performed using a stereoscopic microscope with an epifluorescent module. The results from this study revealed that the amount of aerosolized particles delivered using a commercial nebulizer was proportional to exposure periods. Aerosol exposure periods of 0.5 hr or 1 hr did not result in a readily observable distribution of 1.0 microm fluorescent microspheres to the cranial thoracic, caudal thoracic, or abdominal air sac membranes. This was partly attributed to the relatively low concentration of the individual monodisperse microspheres in the aerosolized suspension. The 2- and 4-hr exposure periods resulted in readily observable deposition of the 1.0 mirom fluorescent microspheres in the cranial thoracic, caudal thoracic, or abdominal air sac membranes, with the 4-hr exposure period resulting in the greatest number of particles on the membrane surfaces. For each of the exposure periods, there was individual animal variation regarding the distribution and relative number of spheres deposited. This study demonstrates the widespread deposition of particles that had an aerodynamic equivalent diameter of approximately 1 microm and provides a better understanding of particle deposition efficiency within the respiratory system following aerosol exposure in birds.     

Concurrent use of a medial saphenous fasciocutaneous free tissue flap and external skeletal fixation for treatment of a distal antebrachial injury in a dog

OBJECTIVE: To report the surgical management of a traumatic distal antebrachial wound using a medial saphenous fasciocutaneous free tissue flap and a type I external skeletal fixator (ESF). STUDY DESIGN: Case report. ANIMALS: A 7-year-old spayed, female Labrador retriever. RESULT: Wound coverage and pancarpal arthrodesis were accomplished during a single anesthetic episode using a medial saphenous fasciocutaneous free tissue flap and type I ESF. A second surgical procedure was performed to expedite healing of part of the original wound that was initially left to heal by second intention. CONCLUSIONS: Free tissue transfer can be used in combination with an ESF for repair of distal antebrachial wounds, allowing orthopedic repair and soft tissue coverage in a single anesthetic episode. CLINICAL RELEVANCE: Concurrent use of free tissue transfer and carpal arthrodesis with an ESF could be used for repair of complex antebrachial wounds without need for multiple procedures, extended hospitalization, and increased cost.     

Laparoscopic ovariohysterectomy in nine dogs

Minimally invasive surgery has been found in humans to reduce pain, incidence of infections, and duration of hospitalization. Minimally invasive procedures are also being described in veterinary medicine. Laparoscopic ovariohysterectomy (OHE) was performed on nine, healthy, intact female dogs using a Harmonic scalpel. Creatine kinase values were determined both before and 12 hours following the laparoscopic OHE; the magnitude of the difference between preoperative and postoperative creatine kinase values did not correlate with length of operative time, length of incisions, or amount of hemorrhage. Complications included one dog that had an omental herniation that was primarily repaired and one dog with seroma formation. Median surgical time for all dogs was 60 minutes (range, 35 to 100 minutes).     

Recurrence of spontaneous lung lobe torsion in a pug

Lung lobe torsion (LLT) results from a displacement and twisting of a lung lobe around its bronchovascular pedicle. This relatively rare disorder affects dogs, cats, and humans. Etiologies include primary (i.e., spontaneous) and secondary torsion due to thoracic trauma, pleural space disease, thoracic surgery, pulmonary parenchyma disease, and diaphragmatic hernia repair. Although both spontaneous and secondary torsion have been described in small-breed dogs, a spontaneous LLT followed by recurrence of a spontaneous LLT > 2 years later has not been documented. This article describes the presentation, diagnosis, management, and outcome of a pug with recurrent spontaneous LLT.