Species proportions by area in mixtures of Scots pine (<Emphasis Type="Italic">Pinus sylvestris</Emphasis> L.) and European beech (<Emphasis Type="Italic">Fagus sylvatica</Emphasis> L.)

Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) dominate many of the European forest stands. Also, mixtures of European beech and Scots pine more or less occur over all European countries, but have been scarcely investigated. The area occupied by each species is of high relevance, especially for growth evaluation and comparison of different species in mixed and monospecific stands. Thus, we studied different methods to describe species proportions and their definition as proportion by area. 25 triplets consisting of mixed and monospecific stands were established across Europe ranging from Lithuania to Spain in northern to southern direction and from Bulgaria to Belgium in eastern to western direction. On stand level, the conclusive method for estimating the species proportion as a fraction of the stand area relates the observed density (tree number or basal area) to its potential. This stand-level estimation makes use of the potential from comparable neighboring monospecific stands or from maximum density lines derived from other data, e.g. forest inventories or permanent observations plots. At tree level, the fraction of the stand area occupied by a species can be derived from the proportions of their crown projection area or of their leaf area. The estimates of the potentials obtained from neighboring monospecific stands, especially in older stands, were poorer than those from the maximum density line depending on the Martonne aridity index. Therefore, the stand-level method in combination with the Martonne aridity index for potential densities can be highly recommended. The species’ proportions estimated with this method are best approximated by the proportions of the species’ leaf areas. In forest practice, the most commonly applied method is an ocular estimation of the proportions by crown projection area. Even though the proportions of pine were calculated here by measuring crown projection areas in the field, we found this method to underestimate the proportion by 25% compared to the stand-level approach.     

Regeneration dynamics in aging black pine (<Emphasis Type="Italic">Pinus nigra</Emphasis> Arn.) plantations on the south slopes of the Middle Balkan Range in Bulgaria

To study the regeneration dynamics in mature black pine (Pinus nigra Arn.) plantations in the Middle Balkan Range, Bulgaria, a total of 48 research plots (sized 0.1 ha) were established; 26 plots were established in the foothills of the mountains (foothill zone) and 22 in the main massive (mountainous zone). Pine overstorey as well as advance regeneration in subplots were recorded. Analysis of variance and regression analysis showed that in general relative stand basal area (RSBA) was the most important predictor of deciduous advance regeneration density, top height as well as age span of the regeneration layer. In the mountainous zone soil depth (SD) and the presence of mature deciduous trees (MDT) explained a significant amount of the variation in regeneration features. Lower RSBA induced by earlier thinnings resulted in higher regeneration density, larger top heights and wider age span of deciduous species. Under the pine canopy oak regeneration can persist longer compared to natural broadleaved canopies. In the studied plantations pine regeneration was confined to few scattered seedlings and regeneration groups. Based on these findings silvicultural concepts for the further management of black pine plantations in the Middle Balkan Range are discussed.     

Evaluation of Cisplatin as an electrochemotherapy agent for the treatment of incompletely excised mast cell tumors in dogs

Background: Electrochemotherapy (ECT) couples the administration of anticancer drugs with the delivery of electric pulses that increase the drug uptake through the cell membranes, resulting in an improved efficacy. Hypothesis: To evaluate the tolerability and efficacy of cisplatin (CDDP) as an ECT agent to prevent recurrence of incompletely resected mast cell tumors (MCTs). Animals: Thirty‐seven dogs. Methods: Prospective study recruiting dogs with incompletely excised MCTs as confirmed by surgeon and pathology reports. After debulking, the tumor bed and margins were infiltrated with CDDP, and then exposed to trains of biphasic electrical pulses under sedation. Five minutes after the injection of the chemotherapy agent, sequences of 8 biphasic pulses lasting 50 + 50 μs each, were delivered in bursts of 1,300 V/cm for sclerosed and of 800 V/cm for exposed lesions, with caliper or needle array electrodes, respectively. A second session was performed 1 or 2 weeks later based on clinical considerations. Results: The treatment was well tolerated with minimal adverse effects. Twenty‐nine dogs had no evidence of recurrence over the 6‐year study period, 6 had tumor recurrence, 1 died of multiple cutaneous MCTs, and 1 died of unrelated causes. The estimated median time to recurrence was 1,200 days. Recurrence was not observed among the long‐term (>1 year) treated dogs. Conclusions and Clinical Importance: ECT with CDDP appears effective in the treatment of incompletely resected MCT in dogs and could be a useful addition to the current options based on its low cost, limited toxicity, and ease of administration.     

Ganglioneuroblastoma in a cat: a rare neoplasm treated with electrochemotherapy

An 8-year-old male castrated cat was referred for sudden onset of lameness. Physical examination revealed a 1x2x1cm mass originating from a footpad of the right hind leg. A diagnosis of ganglioneuroblastoma was suggested by the tumour appearance following histopathological staining with haematoxylin and eosin and haematoxylin/van Gieson. Immunohistochemical staining for glial fibrillary acidic protein (GFAP), vimentin, neuron-specific enolase (NSE), neurofilament and S100 further confirmed the diagnosis. The staging process did not indicate metastatic spread. The cat was treated with three sessions of electrochemotherapy (ECT) 1 week apart, following local injection of bleomycin. The tumour had completely regressed within 1 week of the third ECT application and remained in remission for 402 days at which time a small recurrence was noted. The animal was given a further session of ECT using intra-lesional cisplatin and again went into remission. It remained tumour free at 450 days. Electrochemotherapy is considered a safe and effective treatment for localised neoplasms of cats and dogs and warrants further investigation.     

Electrochemotherapy for the treatment of squamous cell carcinoma in cats: a preliminary report

Squamous cell carcinomas (SCC) of the skin are commonly described in cats. Reported treatments include surgery, radiation therapy and photodynamic therapy. This preliminary study reports on the management of these lesions combining the local administration of bleomycin (plus hyaluronidase for a more uniform distribution) with permeabilizing biphasic electric pulses. Nine cats with SCC graded T(2)-T(4) were treated over a 5 year period, and each cat received two sessions of electrochemotherapy (ECT) 1 week apart. The side effects of this treatment were minimal and limited to mild erythema of the nose. Seven of the cats (77.7%) had a complete response lasting up to 3 years. ECT seems to be a safe and effective option for the treatment of feline sun-induced squamous cell carcinomas and warrants further investigation.     

Electrochemotherapy treatment for bilateral pleomorphic rhabdomyosarcoma in a cat

A 13-year-old male neutered cat was presented for the sudden growth of two nodular lesions close to the upper eyelid of both eyes. Fine-needle aspiration cytology was suggestive of mesenchymal neoplasia. The cat had conservative surgical excision in order to preserve the eyelids’ functionality; however, the histopathological report came with a diagnosis of incompletely excised bilateral pleomorphic rhabdomyosarcoma. Due to the local aggressiveness of this neoplasm, the cat was treated with two sessions of cisplatin-based electrochemotherapy, delivered 14 days apart. Systemic or local toxicities were not detected during the whole course of therapy. The cat is still in complete remission after 12 months. Electrochemotherapy is a safe and efficacious adjuvant therapy for aggressive sarcomas and warrants further investigations in order to standardise its protocols.     

Scaling issues in forest ecosystem management and how to address them with models

Scaling is widely recognized as a central issue in ecology. The associated cross-scale interactions and process transmutations make scaling (i.e. a change in spatial or temporal grain and extent) an important issue in understanding ecosystem structure and functioning. Moreover, current concepts of ecosystem stewardship, such as sustainability and resilience, are inherently scale-dependent. The importance of scale and scaling in the context of forest management is likely to further increase in the future because of the growing relevance of ecosystem services beyond timber production. As a result, a consideration of processes both below (e.g. leaf-level carbon uptake in the context of climate change mitigation) and above (e.g. managing for biodiversity conservation at the landscape scale) the traditional focus on the stand level is required in forest ecosystem management. Furthermore, climate change will affect a variety of ecosystem processes across scales, ranging from photosynthesis (tree organs) to disturbance regimes (landscape scale). Assessing potential climate change impacts on ecosystem services thus requires a multi-scale perspective. However, scaling issues have received comparatively little attention in the forest management community to date. Our objectives here are thus first, to synthesize scaling issues relevant to forest management and second, to elucidate ways of dealing with complex scaling problems by highlighting examples of how they can be addressed with ecosystem models. We have focused on three current management issues of particular importance in European forestry: (1) climate change mitigation through carbon sequestration, (2) multi-functional stand management for biodiversity and non-timber goods and services and (3) improving the resilience to natural disturbances. We conclude that taking into account the full spatiotemporal heterogeneity and dynamics of forest ecosystems in management decision-making is likely to make management more robust to increasing environmental and societal pressures. Models can aid this process through explicitly accounting for system dynamics and changing conditions, operationally addressing the complexity of cross-scale interactions and emerging properties. Our synthesis indicates that increased attention to scaling issues can help forest managers to integrate traditional management objectives with emerging concerns for ecosystem services and therefore deserves more attention in forestry.     

Electrochemotherapy for the Treatment of Multiple Melanomas in a Horse

A 22-year-old Camargue mare was referred for showing signs of discomfort during chewing, building up of food in the mouth, and foul odor from the mouth. On physical examination, the mare presented bilateral pigmented labial masses affecting the upper and lower lips, more in the form of plaques at the mucocutaneous junction as well as multiple perivulvar and perianal lumps. The skin lesions were biopsied for histopathologic examination and the clinical suspect of melanoma was confirmed. The owner elected the lesions to be treated with electrochemotherapy using the drug cisplatin. After two sessions, the nodules were shrunk by 50% and the horse’s ability to feed normally was restored: at that time, the owner had the treatment discontinued because of financial issues. The horse is still in partial remission after 1 year from the end of the treatment. Electrochemotherapy can be successfully used to palliate large melanomas in horses.     

Modeling diameter distribution of Austrian black pine (<Emphasis Type="Italic">Pinus nigra</Emphasis> Arn.) plantations: a comparison of the Weibull frequency distribution function and percentile-based projection methods

The main purpose of the present investigation is to examine and compare three methods for diameter distribution modeling in terms of their fitness to predict from stand level variables the diameter distributions of even-aged Austrian black pine (Pinus nigra Arn.) plantations in Bulgaria. The percentile-based projection method involving empirical probability density function based on 12 percentiles was the first method tested. A new modified approach based on the first method was proposed as the second alternative. The third method was the 2-parameter Weibull functional model in which parameters were recovered from the first and the second raw moments and the second central moment of the empirical distributions. The Kolmogorov–Smirnov test was applied to compare the experimental distributions with the predicted ones, and estimation of the error indices was employed to evaluate the total absolute deviation of the predicted numbers from the actual ones by diameter class. The two-parameter Weibull function proved superior to the examined alternative percentile-based projection methods and the newly proposed percentile method, without a driver percentile showed improved precision compared to the classical percentile method (with a driver percentile). The parameters of the Weibull frequency distribution function can be easily recovered from the stand quadratic mean diameter. Consequently, this diameter distribution model could be incorporated as a sub-model for stand horizontal structure characterization within the Stand Density Management Diagram modeling framework.