Long-term effects of Macroternies termites, herbivores and annual early fire on woody undergrowth community in Sudanian woodland, Burkina Faso

Termites, herbivores and fire are recognized as major guilds that structure woody plant communities in African savanna and woodland ecosystems. An understanding of their interaction is crucial to design appropriate management regimes. The aim of this study was to evaluate the long-term impacts of herbivore, fire and termite activities on regeneration of trees. Permanent experimental quadrats were established in 1992 in the Sudanian woodland of Burkina Faso subjected to grazing by livestock and annual early fire and the control. Within the treatment quadrats, an inventory of the woody undergrowth community was conducted on termitaria occupied by Macrotermes subhyalinus, extended termitosphere (within 5 m radius from the mound base) and adjacent area (beyond 5 m from the mound base). Hierarchical analysis was performed to determine significant differences in species richness, abundance and diversity indices among vegetation patches within fire and herbivory treatments. Grazed quadrats had significantly (P < 0.001) more species and stem density of woody undergrowth than non-grazed quadrats but maintained similar level of species richness and stem density of woody undergrowth on termitaria. There were not significant differences (P>0.05) in species richness and stem density between burnt and unburnt quadrats. Termitaria supported a highly diverse woody undergrowth with higher stem density than either the extended termitosphere or rest of quadrats. The density of woody undergrowth was significantly related with mature trees of selected species on termitaria (R-2 = 0.593; P<0.001) than that on the extended termitosphere (R-2 = 0.333; P<0.001) and adjacent area (R-2 = 0.197; P<0.001). It can be concluded that termites facilitate the regeneration of woody species while grazing and annual early fire play a minor role in the regeneration of woody species. The current policy that prohibits grazing should be revised to accommodate the interests of livestock herders. (C) 2014 Elsevier GmbH. All rights reserved.

Regeneration of Juvenile Woody Plants after Fire in a Seasonally Dry Tropical Forest of Southern India

Woody tree species in seasonally dry tropical forests are known to have traits that help them to recover from recurring disturbances such as fire. Two such traits are resprouting and rapid post-fire growth. We compared survival and growth rates of regenerating small-sized individuals (juveniles) of woody tree species after dry season fire (February-March) at eight adjacent pairs of burnt and unburnt transects in a seasonally dry tropical forest in southern India. Juveniles were monitored at 3-mo intervals between August 2009 and August 2010. High juvenile survivorship (>95%) was observed in both burnt and unburnt areas. Growth rates of juveniles, analyzed at the community level as well as for a few species individually (especially fast-growing ones), were distinctly higher in burnt areas compared to unburnt areas after a fire event, particularly during the pre-monsoon season immediately after a fire. Rapid growth by juveniles soon after a fire may be due to lowered competition from other vegetative forms such as grasses, possibly aided by the availability of resources stored belowground. Such an adaptation would allow a juvenile bank to be retained in the understory of a dry forest, from where individuals can grow to a possible fire-tolerant size during favorable conditions.

Can frequency diversity provide performance gains for WSNs at 2.4GHz for the fire hydrant to above ground channel

Wireless Sensor Networks (WSNs) which utilise IEEE 802.15.4 technology offer the potential for low cost deployment and maintenance compared with conventional wired sensor networks, enabling effective and efficient condition monitoring of aged civil engineering infrastructure. We will address wireless propagation for a below to above ground scenario where one of the wireless nodes is located in a below ground fire hydrant chamber to permit monitoring of the local water distribution network. Frequency Diversity (FD) is one method that can be used to combat the damaging effects of multipath fading and so improve the reliability of radio links. However, no quantitative investigation concerning the potential performance gains from the use of FD at 2.4GHz is available for the outlined scenario. In this paper, we try to answer this question by performing accurate propagation measurements using modified and calibrated off-the-shelf 802.15.4 based sensor nodes. These measurement results are also compared with those obtained from simulations that employ our Modified 2D Finite-Difference Time-Domain (FDTD) approach. ©2009 IEEE.

Les Portugais d'Amérique : souvenirs historiques de la guerre du Brésil en 1635 : contenant un tableau intéressant des moeurs et usages des tribus sauvages, des détails instructifs sur la situation des colons dans cette partie du nouveau-monde : ouvrage destiné a la jeunesse

Illustré de 12 dessins impremés en 2 couleurs

The lowland dry zone of Sri Lanka: site for study of aquaculture development within farmer-managed irrigation systems and methodology for participatory situation appraisal

The aims of this paper are twofold. Firstly to characterise rural poverty and to give a broad overview of the agro-ecological, climatic and socio-economic conditions in Sri Lanka which shape poverty. Secondly to present the methodology employed to screen suitable field research areas and the techniques subsequently used to carry out Rapid Rural Appraisal in two upper-watersheds villages. Also presented are details of a concurrent stakeholder analysis that aimed to investigate the capacity of secondary stakeholders to promote sustainable aquatic resource development and to invite their participation in the formulation of a participatory research agenda.[PDF contains 58 pages]

Die Situation der Makrelen- und Stöckerbestände. Der deutsche Beitrag zur internationalen Bestandsabschätzung

The question has not yet been completely solved whether or not the mackerel and horse mackerel stocks in the waters from the Bay of Biscay to the Atlantic off the Norwegian coast are independent unit stocks or must be regarded rather as one stock with distinct stock components. The stock definition, however, is the basis for fishery management and is fundamental for the exploitation of the stocks. For this reason the extensive mackerel and horse mackerel egg survey carried out in 1998, is of high importance and significance for the fishery management of the two species. The survey has begun in January in Iberian waters and will eventually end in the autumn north of Scotland. To cope with this task research vessels of eight European nations are participating.

Situation awareness application

This thesis describes the design and implementation of a situation awareness application. The application gathers data from sensors including accelerometers for monitoring earthquakes, carbon monoxide sensors for monitoring fires, radiation detectors, and dust sensors. The application also gathers Internet data sources including data about traffic congestion on daily commute routes, information about hazards, news relevant to the user of the application, and weather. The application sends the data to a Cloud computing service which aggregates data streams from multiple sites and detects anomalies. Information from the Cloud service is then displayed by the application on a tablet, computer monitor, or television screen. The situation awareness application enables almost all members of a community to remain aware of critical changes in their environments.

Situation wirtschaftlich wichtiger Grundfischbestände vor Norwegen, Spitzbergen und in der Barents-See

Assessments on NE-arctic stocks of cod, haddock, saith, redfish and Greenland halibut were carried out by the ICES 'Arctic Fisheries Working Group' in August 1996. Whereas stocks of cod, haddock, and saithe are presently in fairly good and stable condition the assessments show the stocks of beaked redfish and Greenland hailibut to be just the opposite. The status of the golden redfish stock seems to be stable. More detailed information is given in this report.

Über die Situation des Kabeljaubestandes in der Nordsee, unter besonderer Berücksichtigung der Deutschen Bucht

Seit der letzten speziellen Situationsbeschreibung des Kabeljaubestandes in dieser Zeitschrift sind 4 Jahre vergangen (EHRICH, 1988). In der Zwischenzeit ist besonders den Fischern durch weitere Fangeinbußen bewußt geworden, daß sich der Zustand des Bestandes nicht verbessert, sondern im Gegenteil weiter verschlechtert hat. Die Schonmaßnahmen wie stufenweise Erhöhung der vorgeschriebenen Mindestmaschenweite auf 100 mmm und eine Reduzierung des Fischereiaufwandes in den Jahren 1991 und 1992 auf 70 % des Aufwandes in 1989 (Mindesthafenliegezeit: durchgehend 8 Tage pro Monat oder alternativ Erhöhung der Mindestmaschenweite auf 110 mm für die direkte Fischerei auf Kabeljau und Schellfisch) haben keine positive Wirkung gezeigt.

Westgrönland, der Kabeljaubestand und die hydrographische Situation im Herbst 1988

Über die positive Entwicklung des Kabeljaubestandes unter Westgrönland, ab Mitte der 80iger Jahre wurde bereits im Vorjahr berichtet. Die mit FFS "Walther Herwig" im Herbst 1987 erzielten Surveyergebnisse dokumentieren einen steilen Anstieg der Bestandsgröße sowohl hinsichtlich der Individuenzahl (Abundanz) als auch des Bestandsgewichts (Biomasse) um das 4-fache auf 583 Millionen Fische bzw. um das 6-fache auf 464000 Tonnen. Diese Bestandszunahme war zahlenmäßig zu 88% und gewichtsmäßig zu 85% auf die Rekrutierung der 3 jährigen Kabeljau des starken Nachwuchsjahrganges 1984 zurückzuführen.