100,784 research outputs found
Guide de poche des dendromicrohabitats: Description et seuils de grandeur pour leur inventaire
No full textCe guide de poche est une annexe à la Notice pour le praticien: Bütler, R.; Lachat,T.; Krumm,F.; Kraus, D.; Larrieu, L., 2020: Connaître, conserver et promouvoir les arbres-habitats. Not. prat. 64:12 p
The impact of forest management on saproxylic beetles and other arthropods in a semi-deciduous forest in Southern Benin
No full textTropical forest ecosystems worldwide are suffering from anthropogenic pressures leading to deforestation and forest degradation, and resulting in a loss of biodiversity. Because tropical forests sustain over half of the planet’s life forms, their destruction might evoke an ecological crisis of global dimension. However, in spite of an increasing awareness of the general public and political authorities, tropical forests continue to deteriorate unabatedly, and numerous species are getting extinct every day. At the same time, large-scale reforestation and afforestation programmes in the tropics have been launched to produce timber and fuelwood. Moreover, it has been proposed that plantation forests have an important role to play in maintaining or enhancing regional biodiversity pools and in alleviating anthropogenic pressures on the natural forests remaining. Consequently, studies about the role of forest plantations for biodiversity conservation are emerging worldwide. However, there is a dearth of information from Africa, and basically none about the arthropod fauna in African forest plantations. The present study steps into this gap and aims to generate baseline data about the diversity of arthropods in natural and plantation forests in tropical West Africa. In doing so, it wishes to encourage and inspire the development and implementation of conservation-oriented forest management strategies.
We studied arthropod assemblages in the Lama forest reserve in Southern Benin, an area harbouring one of the last remnants of natural forest in the Dahomey gap. We compared arthropods from different types of forest, including natural, degraded and plantation forest. The fully protected core of the reserve, the so-called Noyau central, is composed of a small-scale mosaic of natural and degraded semi-deciduous Guineo-Congolian forest. It is surrounded by teak (Tectona grandis) and fuelwood (predominantly Senna siamea) plantations. The particular geographical configuration of the reserve provided an ideal set-up to study the impact of different forestry management systems on arthropod diversity and the role of plantations for biodiversity conservation.
In the first chapter, we give an overview of arthropod diversity in the Lama forest reserve, focusing on species related to biomass decomposition, and highlight its importance for biodiversity conservation. No differences in arthropod species richness were found among different forests types within the Noyau central. However, great differences were observed between forest plantations. Of the environmental variables influencing arthropod assemblages, soil type was the most important natural factor, and species richness was highest in soils with coarse texture (old plantations and isolated forest fragments). The remaining variables naturalness, understorey cover and canopy height are related to silvicultural practices and are therefore amenable to an improved, conservation-oriented forest management. High values for β-diversity suggest that all major forest habitats contribute significantly to regional species pools und should therefore be protected.
Chapters two to four deal with beetles dependent on dead wood (saproxylics). Saproxylic beetles are an exceptionally species-rich ecological group. Moreover, they are known to be highly sensitive to forest management and are therefore particularly endangered. Despite this, invertebrate diversity studies in Africa have largely ignored saproxylic beetles and their dead wood habitat.
In the second chapter, we investigate the attraction of freshly cut wood for pioneer beetles, using a newly designed trap (twin-Malaise trap) baited with native and exotic wood and exposed in both natural and plantation forests. Six species showed primary attraction and two repulsion. Three species were native wood specialists, but none were teak specialists. Among the beetles showing primary attraction, we found no economically important pest species. The twin-Malaise trap proved to be a suitable device to examine the primary attraction of beetles. However, our study also showed that the entire spectrum of wood-associated beetles cannot be sampled with this type of trap.
In the third chapter, the diversity of saproxylic beetles and their interaction with dead wood are examined for the first time in an African tropical forest. Both the quantity and quality of dead wood resources differed greatly among natural forest and plantations. Dead wood of advanced decay stage and larger size was basically absent in plantations. Despite this paucity of dead wood, saproxylic beetle diversity in teak and fuelwood plantations was surprisingly high. Nonetheless, overall species richness of saproxylic beetles was higher in natural forest, and wood beetle assemblages differed clearly between natural forest and plantations. The volumes of recently dead wood, large pieces of dead wood, coarse woody debris and standing dead trees were found to have the most significant influence on the composition of saproxylic beetle assemblages.
The last chapter focuses on standing dead trees (snags). We found similar species richness of saproxylic beetle assemblages from native and exotic snags. However, overall species richness and β-diversity were higher for native snags, reflecting higher habitat heterogeneity in the protected forest. Species assemblage composition, influenced mainly by the forest system, revealed high heterogeneity, especially among snags of native tree species. Our results showed that retaining or even creating snags is crucial to the protection of saproxylic beetle assemblages.
The results presented here provide evidence that the cultivation of exotic trees in the vicinity of natural forest may be an important element in biodiversity conservation. The system practiced in Lama forest, which combines different management intensities from unmanaged natural forest to intensively managed, short-rotation fuelwood plantations, goes well beyond the single-objective forestry approaches practiced in other tropical areas. The functional and spatial diversity of Lama forest is reflected in a high diversity of saproxylic beetles and other arthropods. The forest ecosystem as a whole benefits from the diversity and abundance of these invertebrates and the ecological services they provide (decomposition, nutrient cycling). Last not least, the rich and varied invertebrate fauna promotes species higher up the food chain feeding on them.
Several conservation-oriented management measures can be proposed to foster the role of plantation forests as habitat surrogates for forest species. In the short term, the regeneration and development of species-rich understorey vegetation of the Guineo-Congolean phytogeographical region should be promoted in plantations. Moreover, different types of dead wood should be retained to improve the resource base for saproxylic beetles. When adopting long-term strategies that aim to integrate biodiversity conservation into tropical forestry, native trees should be planted or allowed to regrow spontaneously within plantation schemes so as to provide a stock of trees that mature and die in plantations
Letter, [Author unclear] to Paulina T. Merritt
No full textHandwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
Guide de poche des dendromicrohabitats. Description et seuils de grandeur pour leur inventaire dans les forêts tempérées et méditerranéennes (2e édition)
No full textPERLCe guide de poche est une annexe à la Notice pour le praticien: Bütler R., Lachat T., Krumm F., Kraus D., Larrieu L. (2020) Connaître, conserver et promouvoir les arbres-habitats. Not. prat. 64:12 p.2e éditio
Acute aortic dissection: a case report showing penetrating thoracic aortic ulcer and infrarenal aortic rupture
No full textAn acute aortic syndrome with simultaneous presence of a penetrating aortic ulcer, an intramural haematoma, a thoracic aortic dissection and an abdominal aortic aneurysm rupture has not previously been reported. Herein, we describe our experience with a patient treated by endovascular means with an 8-year follow-up
Field Guide to Tree-related Microhabitats. Descriptions and size limits for their inventory in temperate and Mediterranean forests (2nd edition)
No full textPERLBütler R., Lachat T., Krumm F., Kraus D., Larrieu L. (2024). Field Guide to Tree-related Microhabitats. Descriptions and size limits for their inventory in temperate and Mediterranean forests. Birmensdorf, Swiss Federal Institute for Forest, Snow and Landscape Research WSL. 64 p. Second, revised edition. The Swiss Federal Institute for Forest, Snow and Landscape Research WSL conducts solution-orientated research on forests, landscapes, biodiversity, natural hazards, and snow and ice in a changing world. As a federal research institute and part of the ETH Domain, it is committed to excellence in research and implementation..
This guidebook was originally published as an annex to: Bütler R., Lachat T., Krumm F., Kraus D., Larrieu L. (2020) Know, protect and promote habitat trees. WSL Fact Sheet 64: 12 p.2nd editio
How to diagnose and treat abdominal compartment syndrome after endovascular and open repair of ruptured abdominal aortic aneurysms
No full textIntra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are frequently encountered in patients treated for ruptured abdominal aortic aneurysms (rAAA) and carry a high morbidity and mortality risk. Despite these facts, IAH/ACS are still overlooked by many physicians, timely diagnosis is missed and treatment often inadequate. All staff involved in the treatment of rAAA should be aware of the risk factors predicting IAH/ACS, the profound implications and derangements on all organ systems, the clinical presentation, the appropriate measurement of intra-abdominal pressure to detect IAH/ACS and the current treatment options for these detrimental syndromes. This comprehensive review provides contemporary knowledge that should help to improve patient survival and long-term outcome
Less invasive (common) femoral artery aneurysm repair using endografts and limited dissection
No full textOBJECTIVE: We report our experience with the treatment of femoral artery aneurysms (FAAs) under local anaesthesia with limited dissection, using endografts to facilitate the proximal anastomosis and some distal anastomoses.
METHOD: Between January 2006 and December 2010, six males, mean age 72 years (range, 65-80 years) with FAAs were treated at the University Hospital of Zurich. All operations were performed under local anaesthesia with analgosedation, except for one performed under spinal anaesthesia. After limited dissection and puncture of the anterior wall of the FAA, a sheath and a self-expanding endograft were introduced over a guide wire and with fluoroscopy they were guided intraluminally into the proximal normal neck of the FAA and deployed. Proximal arterial control was achieved with a balloon catheter introduced through the endograft. Then the FAAs were opened and distal arterial control is obtained with balloon catheters. The distal end of the stent graft was then sutured to the normal-sized distal arteries or to stent grafts placed within them.
RESULTS: Of the six FAAs, four were true and two were false anastomotic aneurysms. Mean FAA diameter was 5.0 cm (range, 3.0-6.5 cm). Four patients also had aneurysmal involvement of the external iliac artery, one patient also had deep femoral aneurysms, but deep femoral circulation was always preserved. In three of the patients, the distal anastomosis was created to the femoral artery bifurcation, in two patients to the deep femoral artery when the superficial femoral artery (SFA) was chronically occluded and in one patient to the SFA. Immediate technical success was achieved in all six patients, and graft patency was observed from 9 to 48 months (mean 29 months). There were no amputations, complications or deaths.
CONCLUSION: This technique for repair of FAAs can be performed under local anaesthesia, minimises dissection and complications and simplifies exclusion of these lesions. It is of particular value in high-risk patients with large FAAs
Periscopes, chimneys, sandwich and VORTEC to facilitate abdominal and thoracoabdominal aortic aneurysm repair
No full textThe VORTEC (VIABAHN open revascularization technique) and the chimney graft technique are tools with which to maintain or restore blood flow to the aortic branches and can be used intentionally or as a bailout procedure in open surgery or endovascular procedures. VORTEC is a stent graft-based vascular connection technique that achieves end-to-end anastomosis configuration; it is especially useful when the traditional suture technique proves (can be) cumbersome. It is also a speedy tool with virtually no blood flow interruption and no anastomotic bleeding, and patency rates compare favorably with sutured anastomosis. The chimney/periscope, as well as the sandwich graft technique (CHIMPES), is an endovascular tool using parallel endografts for maintaining or restoring blood flow to aortic branches, whereas the conventional aortic stent graft will land above their origin. It is a relatively speedy procedure allowing the use of off-the-shelf devices, even for emergency cases. When parallel grafts run in between two aortic stent graft devices, the term“sandwich” is used. Based on the published experience, both techniques seem particularly useful in aortic arch and thoracoabdominal aortic aneurysm repair, especially in high-risk or acute cases
Handwritten biographical information on Paulina T. McClung Merritt
No full textA handwritten biography of Paulina T. McClung Merritt by an unknown author, 1892.
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